VOL. 28 OCTOBER 1984 NO. · UK ISSN 0032-1400 PLATINUM METALS REVIEW A quarterly survey of research on the platinum metals and of developments in their application in industry VOL

UK ISSN 0032-1400

PLATINUM METALS REVIEW

A quarterly survey of research on the platinum metals and of developments in their application in industry

VOL. 28 OCTOBER 1984 NO. 4*

Con tents

Platinum Group Metal Catalysis at the End of This Century

Platinum Anti-Cancer Drugs

The Solubility of Hydrogen in the Platinum Metals under High Pressure

Thermophysical Data on Platinum

A Report of Fuel Cell Technology

Catalysts for Sealed Gas Lasers

The Chemistry of thePlatinum Group Metals

High Temperature Durability Trial

A Valuable Review of Ruthenium

Platinum and Early Photography

The Johnson Matthey Collection

J. B. Boussingault and Platinum

Abstracts

New Patents

Index to Volume 28

Communications should be addressed to The Editor, Platinum Metals Review

Johnson Matthey Public Limited Company, Hatton Garden, London E C l N SEE

150

'57

158

'64

165

I 66

I 68

'74

'77

178

I 8 8

'89

190

196

200

Platinum Group Metal Catalysis at the End of This Century PROBABLE SYSTEMS AND THE PROCESSES RASED ON T H E M

By G. J. K. Acres The Johnson Matthey Group

At the annual meeting of the Royal Society of Chemistry, held earlier in the year at Exeter University, Dr. Acres, Director of Research, Johnson Matthey, gave some predictions about platinum group metal catalysed reactions in the year 2000. This article is based upon his lecture.

In looking to the year 2000 and the developments likely to occur in the field of platinum metal catalysis, it is at first sight perhaps tempt- ing to suggest that both the catalyst systems as they are known today, and the processes for which they are used, will be superseded by significantly more efficient catalysts and processes allied to those operating in biochemical processes. For example, one might propose that ammonia will be synthesised at near-ambient temperature, and that methane and synthesis gas will be efficiently converted into fuels and chemical intermediates. Additionally it might be expected that the direct conversion of fuels into electrical energy will become established technology during the next I 5 years. All of this, one might conjecture, would be built on an ability to model catalysts and processes from basic principles. But can and will platinum group metal catalysts develop to this stage by the turn of the century?

To answer this question it is as well to look first at some of the major catalytic processes used in the chemical industry today. These are illustrated in Table I which shows some of the better known processes, the date they were first commercialised and the relevant industry.

It is notable that many of the processes were used 50 or more years ago, that the catalyst and process conditions have not changed significantly since their inception, and that platinum group metals are used in at least half of the applications. A large number of the improvements in catalyst and process have been concerned with better reproducibility in catalyst manufacture and increased durability under reaction conditions. History, therefore, suggests that platinum group metal catalysed processes, once established, tend to remain in use with development occurring continuously rather than in quantum jumps. In some areas of the chemical industry platinum metal catalysts have replaced base metal catalysts, and this is not surprising considering the range of reactions which the six metals catalyse, see Table 11.

Currently platinum group metal catalysts are unique in terms of activity and selectivity for many hydrogenation and oxidation reactions, and as a result they are being used increasingly in the synthesis of chemicals and intermediates. Extrapolating into the future, therefore, it can be said that platinum group metal catalysts will continue to be utilised at the turn of the century. If this is to be the case, it is now necessary to consider the form they are likely to take, and the new processes and systems in which they will be used by the year 2000.

Platinum Croup Metal Catalysts for AD 2000 and Beyond

With the majority of catalytic reactions, one or more of the reactants is adsorbed on the catalyst surface, where reaction takes place. The products then desorb, to be replaced by further reactant. The reactants adsorbed on the

Platinum Metals Rev., 1984, 28, (4) 150-157 150

Table I Maior Catalytic Processes Used i n t h e Chemical Indus t ry

Platinum

Platinum

Platinum

Platinum

Industry

Palladium Ruthenium Rhodium Iridium

Palladium Ruthenium Rhodium Iridium

Palladium

Palladium Ruthenium

Ruthenium

Ruthenium Palladium

Rhodium

Ruthenium Rhodium Iridium

Rhodium

Osmium

Petroleum refining

Fertilisers

Bulk chemicals

Plastics

Fine chemicals

Fats and oils

Pollution control

Application

Catalytic cracking Catalytic alkylation Platforming

Ammonia oxidation Ammonia synthesis

Sulphuric acid Methanol synthesis Ethylene oxide Acetaldehyde Steam reforming

Polyethylene

Hydrogenation

Hydrogenation

Oxidation

Discovery

1915 1935 1950

1838 1913

1831 1924 1931 1960 1962

1955

1900

1901

1949

catalyst surface form chemisorbed activated complexes in equilibrium with reactant in the non-adsorbed condition. The same is true of the products, and it is the relative strengths of adsorption of the reactants and the products which determine how fast the reaction takes place. If eirher the reactant or the product is too strongly absorbed on the catalyst surface then

the equilibria will be biased towards the adsorbed state and the reaction will proceed slowly. If the reactant is too weakly adsorbed then the equilibrium will be biased towards the non- adsorbed state, the concentration of activated complexes will be low, and again the rate of reaction will be slow. Only when the reactants are adsorbed with intermediate strength and

Table II React ions Catalysed by Pla t inum G r o u p Metals

Reaction

Hydrogenation

Oxidation

Dehydrogenation

H ydrogenolysis

Synthesis Ammonia Methanol Hydrocarbons Acetic acid

Hydroformylation

Carbonylation

cis-Hydroxylation

Platinum Metals Rev., 1984, 28, (4) 151

250

200

u - E ‘1. : 1%

f e 2 Yoo n a

n

b

Y X

L-

Fig.

Ti V Cr Mn Fe Co Ni Cu Z r Nb Mo Ru Rh Pd Ag Hf Ta W Re 0 s I r Pt Au

Here initial heats of adsorption of oxygen, carbon monoxide and hydrogen are plotted as a function of the catalyst metal. For each reactant there is a significant decrease on moving from left to right, best illustrated here by oxygen on nickel, palladium and platinum. (After G. C. Bond, Platinum Metals Rev., 1979,23, (2), 5 0 )

the products less strongly adsorbed will the reaction proceed at a commercially interesting rate. Heats of adsorption are related to strengths of adsorption and one test of catalytic ability is the measurement of the heat of adsorption. Figure I illustrates the key function that makes the platinum group metals unique as catalysts (I) . Most of the commercially interesting reactants are adsorbed with moderate strength on the six platinum metals, which explains why these rare and intrinsically valuable metals are used to catalyse so many reactions in preference to more abundant elements, some of which exhibit catalytic properties.

Since the heat of adsorption and thus the strength of adsorption contribute exponentially to the activation energy, minor changes in the heat of adsorption result in major changes in the catalytic activity. This can be seen in Figure

2 which illustrates the catalytic activity of the elements of Groups VA, VIA, VIIA, VIII and IB for ethylene hydrogenation. Clearly the platinum group metals are several orders of magnitude more active than the elements of the other Groups ( I ) .

Similar volcano-shaped curves exist for many other reactions and this illustrates the unique properties of platinum group metal catalysts. For this reason alone platinum group metals will continue to be used.

The Form of the Catalysts T o envisage the form that platinum group

metal catalysts will take in the next few decades it is necessary to look at the materials currently used and then to consider how they may be improved in the future. Since they possess high intrinsic activity, the platinum group metals can be used in the form of bulk metal, indeed


Ruthenium

Palladium

a z P

-2.

! n > I w -3.

w -I

I L

.Chromium

Y-51 , . , . , - VA V I A VIIA VlII I B

PERIODIC GROUP NUMBER

Fig. 2 The rate of ethylene hydrogenation on various metals, relative to rhodium = 1, is plotted here as a function of the Periodic Group Number. The superior catalytic activity of the platinum group metals is clearly illustrated. (After G . C. Bond, Platinum Metals Rev., 1979,23, (2) . 51 )

this was the system originally described at the start of the nineteenth century for ammonia oxidation. Recent progress includes the addition of promoters such as rhodium, and a better understanding of the mechanisms of sintering and metal diffusion phenomena (2, 3).

Alternatively, of course, supported catalysts may be employed and here the range of supports and hence of support surface chemistry is so large that preparation techniques become all important (4). In this field great improvements are being made, and these promise to convert the present art of catalyst preparation into a science.

Platinum on alumina catalysts have been one of the workhorse catalysts of the refining and chemical industries for the last thirty-five years, but even they can still be improved. Impregna- tion technology has changed as the reaction between the platinum salts and the alumina surface has become better understood. Now other platinum group metals and even base metals can be incorporated to improve catalyst performance. For high temperature applications, phase changes in the alumina can be slowed down by the addition of stabilisers. Additionally, current trends suggest the use of other oxide supports particularly titania and zirconia, while the use of molecular sieves as supports is still at an early stage of development. For demanding applications in liquid phase catalysis, platinum on carbon catalysts have reached a high degree of sophistication. It is now possible to control the platinum crystallite size and its dispersion on the carbon support accurately, and to forecast exactly the metal location within the support structure.

New reaction possibilities have been opened up by the recent application of platinum group metal homogeneous catalysts to industrial processes. In the 1960s it was widely thought that homogeneous catalysis had great potential, promising operation under mild conditions, with benefits of high activity, selectivity and durability. Some of this early enthusiasm has had to be tempered by practical experience; none-the-less industrial application has been very successful. Today rhodium catalysed

hydroformylation of propylene to n- butylaldehyde takes place at low temperature (90 to 12o'C) and low pressure (7 to 25 atm). The catalyst, which is dissolved in triphenyl phosphine at a concentration of 200 ppm rhodium, is very active, highly selective and durable. By the year 2000 the range of such reactions is likely to be expanded using either very dilute solutions or supported catalyst systems.

In heterogeneous catalysis the control of activity/selectivity is dependant on controlling the crystallite size of the catalyst, such crystallites containing many metal atoms. On the other hand homogeneous catalysts are usually single metal atom species. It is now possible to bridge these two technologies by using metal cluster compounds containing a number of metal atoms, for example [H2Rh13(C0)24I3- and H2FeRuIOs(CO)1,. Platinum group metals readily form such cluster compounds which may be used as conventional homogeneous catalysts, supported homogeneous catalysts or precursors in the preparation of heterogeneous catalysts. In each of these three systems the metal-metal bonded structure is retained to impart new and unusual properties. For example with heterogeneous catalysts it is anticipated that very close control of crystallite size with multi centre adsorption will be achieved. With homogeneous cluster catalysts the adsorption may be further modified by the ligands, so changing the activity/selectivity abilities of the catalyst. This novel technology offers exciting new possibilities in catalyst design which are likely to be important for both new and established processes by the end of the century (5).

Environmental Control Catalysts One of the more recent developments in the

application of platinum group metal catalysts is for environmental control, and in particular control of the emissions from motor vehicles. This is at present the largest single application of platinum group metal catalysts and it is likely to expand in the future.

As is now well known, motor vehicles


burning hydrocarbons as fuel emit in their exhaust fumes, in addition to water and carbon dioxide, a quantity of other compounds especially carbon monoxide, nitrogen oxides and unburnt hydrocarbons; in ultra violet light these form a photochemical smog.

So far engine modifications alone have not reduced the pollutants sufficiently but catalytic systems have been developed for this purpose. Two systems are presently in use and likely to form the basis of emission control systems for petrol/alcohol fuelled cars in the future (6). The first system removes carbon monoxide and hydrocarbon pollutants over promoted platinum based catalysts. In the second system carbon monoxide, hydrocarbons and nitrogen oxides are controlled catalytically by a platinum-rhodium catalyst containing base metal promoters. These two catalyst systems represent some of the most advanced catalyst technology available, and to date over IOO

million units have been purchased. The increasing use of diesel engined vehicles

in the U.S.A. has resulted in proposed legislation to control the emission of particulate pollutants, and again the challenge has been taken up by catalyst technology. A platinum- rhodium alloy catalyst has been developed which reduces particulates; and polyaromatic hydrocarbons and odour have been largely eliminated from the exhaust stream (7). As long as internal combustion engines remain in use, catalytic emission control is likely to be necessary.

Although accepted solutions have been found to the problem of controlling the pollution from motor vehicles, the control of the pollutants that form “Acid Rain” will require altogether more radical approaches. The emission of both sulphur dioxide and nitrogen oxides from power stations provides a situation in which the two pollutants act synergistically to create a problem bigger than that posed by the two pollutants alone. The removal of sulphur dioxide has a number of solutions including catalytic fuel desulphurisation in which the sulphur is removed from the fuel before it leaves the refinery. Nitrogen oxides, however,

are potentially a bigger problem, as they are formed from atmospheric nitrogen during the combustion process. Measurement of man-made nitrogen oxide emissions in the U.S.A. during I 980 revealed that stationary fuel combustion, consisting of coal fired power generation and hydrocarbon fuelled turbines together with domestic and commercial boilers, produces 52.2

per cent of these emissions while mobile sources such as motor vehicles create 45.6 per cent. The relationship between nitrogen oxides formation and flame temperature is shown in Table 111.

Clearly, the way to reduce nitrogen oxide emissions is to reduce flame temperature or even eliminate the flame completely. Already experimental gas turbines using catalytic com- bustors instead of conventional flame com- bustors have been run successfully. The use of catalysts in a Rover gas turbine engine (8) virtually eliminated nitrogen oxide emissions without loss of engine efficiency. This technology is applicable to oil or gas fired burners and is likely to constitute a major new use of advanced platinum group metal catalyst technology, derived from existing, highly successful car emission control catalyst systems.

The catalytic engine is an exciting application of catalytic combustion technology (9). The benefits of this system include the ignition of leaner mixtures to give better fuel economy and reduced emission of pollutants, while ignition at

Table 111

Formation of Nitrogen Oxides a1 Elevated Temperatures

Temperature O C

1093

1316

1538

1760

1982

Equilibrium concentration

of nitrogen oxides,

PPm

180

5 50

1380

2600

41 50

Time of formation of

500 ppm nitrogen oxides, s

-

1370

16.2

1 .I 0.1 17


Fig. 3 Sometime before the end of this century the demand for oil is experled 10 exceed the supply. Possible produe- tion and demand curves for the Western World, based upon predictions by Shell, show a sub- stantial gap which will have to be met by the use of alternative fuels

optimum compression ratio improves fuel economy further. An additional advantage is that the engine can operate normally on a range of conventional hydrocarbon fuels, or even on alternative fuels such as methanol. This is one of the new concepts in advanced platinum catalyst technology which has possible applications towards the end of this century.

Synthetic Fuels and Chemicals The imminence of the long foreseen gap

between oil demand and production is a matter of some dispute, but on one thing all authorities are agreed; sometime, probably towards the middle or end of the 1990s~ a gap will develop between the demand for oil and the ability to supply it. One such forecast is shown in Figure 3. By the year 2000, in this scenario, there will be a shortage of oil and the need for alternative fuels to bridge the gap will be great. Luckily the interconversion of natural energy sources into fuels and chemicals can potentially be mediated by catalytic processes. This will be a major challenge to catalyst technology in the year 2000. As an example of the use of the platinum group metals in this technology to improve synthetic fuels let us consider the Fischer-Tropsch reaction in which CS - C35 hydrocarbons are selectively manufactured from synthesis gas (carbon monoxide + hydrogen). Two metals of Group VIlI may be used to catalyse the Fischer- Tropsch reaction, namely iron and ruthenium. A comparison of iron and ruthenium as catalysts is shown in Figure 4 and it is notice-

able that ruthenium is more selective, producing a narrower fraction centred on Cs - C1l

which is suitable as a petrol fraction. The use of ruthenium supported on

HZSM-5 zeolite gives a petrol fraction with no

Fig. 4 Improved fuels can be manufactured from synthesis gas by the Fischer-Tropsch reaction using either an iron or a ruthenium catalyst. At a reaction pressure of 8 bars, ruthenium (e l 235'C) is more selective for the production of liquid fuels suitable for use in spark ignition engines than iron ( a t 260°C), while if the pressure is increased to 30 bars ruthenium catalyses an even more selective fraction


Visible Light

I

Ruthenium Complex

P1/TiO2/RuO2 2Hz0 2Hz 0 2

Fig. 5 Over recent years there hab been an abundance of research seeking to harness light as a source of useful energy, the system illustrated here being one of the more successful attempts to decompose water into hydrogen and oxygen. Much remains to be done and the task is, perhaps, one of the most challenging facing scientists

hydrocarbons larger than C I Z and the selectivity is essentially unaltered when the ruthenium loading is decreased from 5 per cent to I per cent metal. Based on this, one may expect to see advanced catalyst systems capable of selectively producing a wide range of fuels and feedstocks.

Fuel Cells Fuel cells produce electricity by the direct

combination of fuels without the limitations imposed by burning fuel, raising steam and rotating a conventional turbine generator ( I 0).

Catalyst technology for the hydrogedair cells using either alkaline or acid electrolytes is now well established. Highly dispersed platinum on carbon catalysts exist in which the metal is dispersed in an almost atomic state. The normally used catalyst has metal crystallites of about 208L diameter. The limiting factor with these cells is not platinum technology but capital costs. Examples of currently used fuel cells are the Space Shuttle I 2 kW unit and the Combined Heat and Power 40 kW unit. This latter unit, incorporating a reformer and an inverter, uses methane or naphtha as fuel and is on extended field trials in both the U.S.A. and Japan. The big brother to the 40 kW unit is the 4.8 MW Peak Lopping Station which again uses natural gas as fuel,

with an incorporated reformer. Units have been installed in New York and Tokyo. The principal benefits of these units are high efficiency and environmental compatibility.

A breakthrough in the use of fuel cells is likely to occur if one that directly uses a readily available fuel can be developed. Possibilities exist for using methanol as a direct fuel; already a prototype golf cart is operating which uses a direct methanol cell. Similar cells also exist for portable consumer electronics, for example video cameras. However, the exploitation of these cells is currently limited by the catalyst technology, since the activity and durability of the platinum-ruthenium on carbon catalysts is relatively low. This forms a major challenge to platinum group metal catalyst technology, which must be met if methanol fuelled cells are to be widely exploited.

Photocatalytic Hydrogen Finally a speculative look at the year 2000 in

terms of a challenging goal that requires advanced platinum group metal catalyst technology, namely the visible light induced decomposition of water. One of the systems investigated is highlighted in Figure 5.

The process uses a sensitiser plus a dual function catalyst. Briefly, the decomposition mechanism involves the excitation of a ruthenium compound dissolved in water by visible light, resulting in the transfer of electrons from this compound to a platinum + ruthenium catalyst. The electrons migrate to the platinum covered areas of this catalyst where they split water and produce hydrogen; at the same time oxygen is formed at the ruthenium covered areas. One of the many problems that will have to be overcome if this system is ever to find application is the spatial separation of the hydrogen and oxygen generating centres so that the two gases can be recovered in pure form.

Summary and Conclusions It is clear that industrial processes which at

present make use of platinum group metal catalysts will continue to do so into the next


century, although it is expected that both the catalysts and the processes will have been improved by continuous development. Hopefully, further deterioration in the environment will be prevented, and both existing and foreseen platinum metal technology has much to contribute to this.

By the year 2000 diminished reserves of gaseous and liquid fossil fuels will be conserved by the more efficient use of fuels, as in the

catalytic engine, while fewer losses will occur when electrical energy is generated directly from the fuel. Chemicals and fuels will be manufactured from more widely available feedstock, principally synthesis gas produced from coal using platinum group metal catalysts.

Although widely used at present, platinum group metal catalysis will undoubtedly have an even greater role to perform at the start of the next century.

References

I G.C.Bond, Plarinum Metals Rev.,r 979,23,(2),46 2 R. T. K. Baker, R. B. Thomas and J. H. F.

Notton, Platinurn Metals Rev., 1974, IS, (4), 130 3 M. Flytzami-Stephanopoulas and L. D. Schmidt,

Prog. Surf. Sci., I 979, 9, 83 4 G. J. K. Acres, A. J. Bird, J. W. Jenkins and F.

King, Spec. Period. Rep. Catalysis Vol. 4, London, Royal Society of Chemistry, I 98 I , 1-30

5 B. C. Gates and J. Lieto, Chemtech, 1980, 10, (3), 195; ibid, 1980, 10, (4), 248

6 G. J. K. Acres and B. J. Cooper, Platinum Metals

7 E. J. Sercombe, Platinum Metals Rev., 1975, 19,

8 B. E. Enga and D. T. Thompson, Platinum

9 R. H. Thring, Platinurn Metals Rev., 1980, 24,

10 H. Van den Broeck and D. S. Cameron, Platinum

Rev., 19723 16, (3h 74

( 1 1 9 2

Metals Rev., 1979,23, (4X 134

(41, '26

Metals Rev., 1984,28, (2), 46

Platinum Anti-Cancer Drugs More than 30,000 cancer patients in the

United States of America are now being treated each year with a combination of drugs which includes Cisplatin. This combination is particularly effective against testicular cancer but Cisplatin is also approved by the Food and Drug Administration (F.D.A.) for first line therapy of ovarian and bladder tumours. These three tumours affect over 60,000 of the 800,ooo new cancer cases reported in the U.S.A. each year. Marketed by Bristol-Myers of New York-who in their 1983 Annual Report to stockholders included a special report on the search for new anti-cancer drugs-Cisplatin is now the leading anti-cancer drug in the U.S.A. and is also registered widely in Europe and most recently ( I 984) in Japan. The compound resulted from a research programme started at Michigan State University in 1965 and sponsored by Rustenburg Platinum Mines and Johnson Matthey. It was developed into a viable product by way of a major project by Johnson Matthey in association with universities, institutes and hospitals in the United Kingdom and in the U.S.A. To produce the drug, Johnson Matthey Inc. set up a special unit at West Whiteland, Pennsylvania in 1978, built to standards approved by the F.D.A. The bulk

drug is supplied to Bristol-Myers for conversion to the final dosage form, suitable for patients treated intravenously, although alternative treatment routes are being investigated. Work on less toxic analogues of Cisplatin,

namely Carboplatin and Iproplatin, was reported at the Second International Platinum Group Metal Chemistry Conference at Edin- burgh, in July 1984. As with Cisplatin, research on the chemistry and pharmacology of these two compounds was progressed by Johnson Matthey through collaborative projects with U.K. institutions notably the Royal Marsden Hospital/Institute of Cancer Research (London) for Carboplatin, and the Christie HospitaVUniversity of Manchester Institute of Science and Technology for Iproplatin. Bristol- Myers have licensed these compounds from Research Corporation and Johnson Matthey, respectively. A major comparative clinical study for these compounds and Cisplatin is now in progress in parallel with the registration procedure for Carboplatin in Europe. Preliminary results show promising activity against a number of other tumours suggesting that a greater proportion of cancer patients will benefit from platinum chemotherapy in the late I 980s. P.C.H.


The Solubility of Hydrogen in the Platinum Metals under High Pressure By V. E. Antonov, I. T. Belash, V. Yu. Malyshev and E. G. Ponyatovsky Institute of Solid State Physics, U.S.S.R. Academy of Sciences, Chernogolovka, 1J.S.S.R.

The technique for compressing macroscopic volumes 0.f hydrogen to record pressures of tens of kilobars, developed in the Institute of Solid State Physics of the USSR Academy of Sciences, has permitted the ,first syntheses of the hydrides o,f a number of metals namely: manganese, iron, cobalt, molybdenum, technetium, rhenium and gold. This paper presents the results of the application of the technique ,for the hydrogenation of the platinum metals. The data obtained on hydrogen solubility at high pressures are used to estimate its equilibrium solubility at atmospheric pressure.

The first metal hydride investigated was that of palladium (I), but more than 120 years passed before the synthesis of a hydride of a second platinum metal, rhodium, occurred (2). To date hydrides of all the transition metals have been synthesised except those of the remaining four platinum metals and tungsten

As far as the platinum metals are concerned, this situation has not resulted from any lack of attempts to synthesise platinum, iridium, osmium and ruthenium hydrides, but is due to their low levels of acceptability of hydrogen into their lattices. This inertness or resistance to hydrogen absorption is characterised by the fact that although the chemical potential of hydrogen dissolved in the metal can be very high, solubilities of hydrogen corresponding to equivalent high external pressures of hydrogen gas, are generally very low.

Even the development of very high chemical potentials within the above metals by traditional non-equilibrium methods (for example, by electrolysis) has not previously been successful in introducing very high hydrogen contents.

The most direct way to increase the chemical potential of the hydrogen is to compress the hydrogen to high pressures. By this means we

(3-5).

have synthesised rhodium hydride (2) by using molecular hydrogen compressed to P H ~ 250 kbar, and recently the range of investigation has been extended to P H ~ Z Z 90 kbar. In this paper we will summarise observations made on platinum metals under such record hydrogen pressures.

The specimens were of 99.99 per cent purity. Palladium, rhodium, iridium and platinum specimens were cut from polycrystalline foils approximately 0. I mm thick, while the ruthenium and osmium specimens with a thickness of about 0. I 5mm were cut from single crystals. Hydrogen compression was carried out by a method which has been outlined (6) and later described in detail (4).

Hydrogen significantly alters the electrical resistance of a metal in which it is dissolved. Thus changes in the electrical resistance of specimens can serve as a conveniently measurable indicator of processes occurring in metal- hydrogen systems at high pressures. Some forms of electrical resistance-pressure isotherms measured in the present work are shown in Figures I and 2. The measurements were obtained as the pressure was altered in steps, each pressure being maintained until any observed drift in resistance had stopped, and the pressure simultaneously became constant. It


Fig. I I so therms of e lec t r i ca l resistance of p a l l a d i u m and rhodium in a hydrogen atmosphere: 0 w i t h increase in pressure 0 w i t h decrease in pressure I t 0 is the resistance of a

specimen a t a tmospher ic pressure a n d room tempera ture

5

4

3

1.7

1 .:

250'C \ Pd-H

2b 4 0 $0 80 HYDROGEN PRESSURE kbnr

J Y

Fig. 2 I so therms of elec- 2 0 t r i ca l resistance of r u t h e n - ium, osmium, iridium and p l a t i n u m a t a tempera ture of 250°C measured w i t h i n r r m s r in p r ~ s s u r e : 0 in an i n e r t m e d i u m

1 0

16

1.84

1

2 . 2 1

RUTHENIUM 1 1.4 '

2 0 40 60 00 PRESSURE htur

0 i n h y d r o g e n KO as def ined in F i g u r e 1 1


should be noted that when the measurements were performed in an inert medium (hexane) no such drifts were observed.

The observations of the drifts in a hydrogen atmosphere are consistent with alterations of the hydrogen content of the specimen. A change of hydrogen concentration in a metal-hydrogen solid solution is a diffusion process, and the duration of the resistance drift characterises the kinetics of the specimen attaining the hydrogen content corresponding to the new magnitude of P H ~ In order that the hydrogenation of the specimens to equilibrium concentrations would occur in a reasonable time, the greater part of the investigations was conducted at elevated temperatures ( 2 2 5 0 0 ~ ) .

For the determination of hydrogen solubility in platinum metals, samples were equilibrated for 24 hours at fixed values of temperature and hydrogen pressure. The high-pressure chamber was then rapidly cooled down to approximately -18oOC; the pressure was next reduced to atmospheric and the specimens were removed from the chamber and stored in liquid nitrogen until their hydrogen contents were determined; this was carried out by a method which has been described elsewhere (5). Testing has shown that at the temperature of liquid nitrogen, no

Fig. 3 Temperature-hydrogen pressure phaw diagram of the rhodium-hydrogen system: 0 preSsure o f the hydride formation

0 prtbsqure o f the hytlridt. decomposition transition y,+y2

transition y2+y ,

detectable loss of the hydrogen takes place from the samples prepared in this way for at least one year.

Palladium The palladium-hydrogen system is one of the

most important and interesting metal-hydrogen systems, and much attention has been paid to its thorough investigation. A detailed review and analysis of the available data on this system can be found elsewhere ( 7 , 8).

As far as the phase composition of the palladium-hydrogen system is concerned, hydrogen and palladium form wide regions of interstitial solid solutions with essential reten- tion of the f.c.c. structure of the lattice of the metal atoms. The T-n diagram (where n is the ratio of hydrogen to metal atoms) of the palladium-hydrogen system exhibits a discontinuity corresponding to co-existence of the isomorphic phases y~ and y 2 (in other literature (7 , 8) designated t i and p or t~ and t k ' ) , depleted and enriched with hydrogen, respectively. On the T-PH, diagram, this is reflected by lines corresponding to the y I + y 2 and y2 + y l , isomorphic transformations ter- minating at a critical point, with parameters of Tcr=2920C, (pH,),,= I 9.7 bar and n,,=o.25 (7) .


Table I

T h e Dependences of the Quantities Entering into Equation ( i ) on Hydrogen Pressure P for T = 25OoC, /3 = 2.5 A3/atom Hydrogen and Po = f, = 1 bar

1 10 20 50 90

I I - I r n > I

1.443 38.0 0.97 37 253.6 504 0.7 1 360 6477 2545 0.50 1.3 x 1 0 3 5.96 x lo6 7.72 x 104 0.18 1.4 x 104 4.4 x 1 0 9 2.1 x 106 0.044 9.2 x 104

n/n 0 ‘p-po’j I P. kbar f, kbar kT

Our measurements have shown that at temperatures above 2ooOC and hydrogen pressures up to 90 kbar, no other transformations occur in the palladium-hydrogen system, and hydrogen solubility in the y 2 phase increases monotonically with pressure up to a hydrogen:metal atomic ratio of n z I at PH, = 90 kbar. Figure I shows a typical isother- mal plot showing changes with pressure of the electrical resistance of the y 2 phase of the palladium-hydrogen system at high pressures. Resistance drifts taking place after alterations of pressure continued for several minutes.

Rhodium The hydriding of rhodium, like that of

palladium, is structurally describable in terms of y1 and y2 interstitial hydrogen solid solution phases, developed from an initial f.c.c. metal lattice whose lattice parameter only finally increases by z 6 per cent (2). At atmospheric pressure and T = - 190’C the lattice spacing of the rhodium hydride with n = 1.02 & 0.03 is a = 4.020A.

The onset of the y1 + y2 transition in the rhodium-hydrogen system at high hydrogen pressures, is indicated by an abrupt increase in the electrical resistance of the specimen, and the y 2 hydride decomposition ( y z + y I transition) by an abrupt decrease in the resistance, see Figure I . The T-PH, diagram of the rhodium- hydrogen system constructed on the basis of a study of the resistance behaviour (9), is shown in Figure 3. As is seen from Figure 3, the temperature dependence of the pressure of the

y2+ 71 transition can be interpolated by a straight line with a slope dT/dpH2z q°C/kbar. At T 2 275OC the extent of the hysteresis of the y1 e y2 transformation is difficult to ascertain in view of the experimental scatter. At T < 27soC, the experimental pressures required for the y1 + y2 transition have been found to increase rapidly, and at ZOOOC it has not been found possible to form the y 2 hydride phase, even at pressures up to P H ~ = 90 kbar.

The observed behaviour of the y l + y2 and y 2 + y l transition curves in Figure 3 makes it somewhat difficult in this case to comment on hypotheses concerning T-PH, diagrams of metal-hydrogen systems (10, I I). Namely that relationships corresponding to true thermodynamic equilibrium are more closely represented by plots of the y1 + y2 hydride formation transition rather than plots of temperature against pressures corresponding to the y2 + y1 hydride decomposition transition.

In the case of the y2 + y1 transition, a linear extrapolation of the slope of the line in Figure 3 yields P H 2 z 25 kbar for the pressure of the y 2 + y 1 transition at OK. From this it would seem reasonable to conclude that the pressure corresponding to thermodynamic equilibrium betyeen yl and y2 phases will not be less than 25 kbar at any temperature above OK.

The essential thermodynamic instability of rhodium hydride shows itself in its strong tendency to decompose back into rhodium and molecular hydrogen. Release of hydrogen from specimens becomes noticeable, even at T z - IOOOC, and at room temperature the


Table II

Hydrogen Solubility in Hutheiiirrm. Orniium. Iricliuni and Pla t inum at 250°(:. The Values ol' n,.l Art, Estiniattvl froni

the Experimental \.'alric~s ii,.,l,lkiiig Equat ion ( i )

Metal Ruthenium Osmium Iridium Platinum

"exp (PH = 90 kbar) 0.03 0.003 5 0.005 5 0.005

"cal (PH,= 1 bar) 3 x 1 0 - 7 3 x 1 0 - 8 5 5 x 1 0 - 8 5 5 x

t

hydride is decomposed in a few minutes. At high hydrogen pressures, the rates of the processes of hydrogen absorption and desorption are quite different, depending on initial and final compositions of the solid. When the pressure is changed in regions of uniformity of either the y l or yz phases, the periods of resistance drift extend only to times AT z 10 to 30 minutes at all temperatures in the range 50 < T < 4ooOC. However when y , + y 2 transitions occur, A s z 1.5 hours at T >, 275OC and this increases to approximately 10 hours at 225OC. The times of resistance drift when y2 + yl transitions occur are somewhat less temperature dependent: Ar z 2.5 hours at T >, 25ooC, approximately I day at IOOOC and approximately I o days at 5oOC.

At 250 < T < 4oo0C, maximum solubilities of hydrogen in the y1 phase initial range of solid solution of hydrogen in rhodium correspond to n 5 0.0 I . However hydrogen contents in the y2 phase are much higher, corresponding to n z I , and ar: almost independent of pressure and temperature.

Huthenium and Osmium Both metals have an h.c.p. lattice. At

T = 250°C, the hydrogen solubility in ruthenium and osmium increases continuously with pressure, reaching n = 0.03 0.01 and n = 0.003 & 0.00 I 5 , respectively, at PH2 = 90 kbar. An increase in the hydrogen concentration in ruthenium and osmium leads to a deviation of the electrical resistance isotherms for these metals when in a hydrogen atmosphere,

compared to those in an inert medium, see Figure 2. In a hydrogen atmosphere a pressure change resulted in a drift in the samples' resistance, lasting for about 2 hours in the case of ruthenium and about 30 minutes for osmium.

The ruthenium-hydrogen and osmium- hydrogen solutions obtained were unstable at room conditions and decomposed into metal and molecular hydrogen in about I day and 10

minutes, respectively.

Iridium and Platinum The metals have a f.c.c. lattice. The hydrogen

content of samples obtained by treatment at T = 250OC and PH2 = 90 kbar reached n = 0.005. At atmospheric pressure and room temperature, the hydrogen completely escaped from the samples in less than a minute. It is to be noted, however, that the behaviour of the electrical resistance of iridium and platinum in a hydrogen atmosphere did not differ significantly from that in an inert medium, see Figure 2. No resistance drift was observed after changes in the hydrogen pressure. In this con- nection, it remains obscure whether, under the experimental conditions, the hydrogen dissolved in the bulk of the metals or if, for example, adsorption took place only on macrodefects.

In view of such low hydrogen solubility in ruthenium, osmium, iridium and platinum even at Pcll = 90 kbar, it would be interesting to estimate what solubility should be observed in these metals under hydrogen pressures of the


order of I bar, which are usually employed for hydrogenation. This might be done by assum- ing that these hydrogen in metal solutions are ideal.

Employing the usual expression for the thermodynamic potential of the solution (12) and representing the chemical potential of molecular hydrogen as pH2= po(T) + kTlnf, the pressure dependence of the concentration of an ideal dilute solution of hydrogen in the metals can be obtained as an expression for the anticipated ratio n/no of the solubility (hydrogen content) n at pressure P to the solubility, no at a pressure Poof I bar:

where k is Boltzmann’s constant, f is the fugacity of hydrogen at temperatureT and pressure P, p is the partial volume of hydrogen in the solution. The exponential factor accounts for an increase in the chemical potential of the hydrogen dissolved in a metal with increasing pressure, due to an increase in the sample volume resulting from the dissolved hydrogen.

For all the metal-hydrogen solutions of Group VI-VIII transition metals and their alloys studied, z 2.5 A3/atom hydrogen, (7 ,4 , 5). The pressure dependences of the quantities entering into Equation (i) are illustrated in Table I. With P0=1 bar and

T = 25ooC, hydrogen is practically an ideal gas, and fox PD The magnitudes o f f for high values of P are estimated by means of the extrapolation formulae (13) using the value of po (25oOC) = - 14783 cal/mole molecular hydrogen ( I 4).

As shown in Table I, the equilibrium concentration of hydrogen in an ideal metal- hydrogen solution at PHI= I bar has to be approximately 105 times lower than that at P H ~ = 90 kbar. For the platinum metals, this yields the magnitudes of hydrogen concentration at PH2 = I bar listed in Table 11.

The obtained values of the equilibrium hydrogen concentration in a perfect defect-free lattice of ruthenium, osmium, iridium and platinum at atmospheric pressure are small compared with the concentration of hydrogen which could be trapped by various micro- and macrodefects and open surfaces ( IS) . For this reason, the effective values of hydrogen sciubility in these metals determined from direct experiments on hydrogen absorption at pressures of the order of I bar may be significantly higher than those of the “true” solubility. For instance, the available experimental data show (3) that at P H 2 = I atm and T = 25ooC, the concentration of hydrogen in platinum should correspond to n x I O - ~ which is approximately 200 times higher than follows from our estimates.

References I T. Graham, Phil. Trans. Roy. SOC., I 866,156,399 2 V. E. Antonov, I. T. Belash, V. F. Degtyareva

and E . G. Ponyatovsky, Dokl. Akad. Nauk SSSR, 19787 2399 (2), 342

3 M. Hansen and K. Anderko, “Constitution of Binary Alloys”, New York, Toronto, London, McGraw-Hill Book Company, 1958

4 E. G. Ponyatovsky, V. E. Antonov and I. T. Belash, Usp. Fiz. Nauk, 1982, 137, 663 (Sow.

5 V. E. Antonov, I. T. Belash, V. Yu. Malyshev, E. G. Ponyatovsky and N. A. Tulina, Dokl. Akad. Nauk SSSR, 1983,269, (3), 617

6 I. T. Belash and E. G. Ponyatovsky, USSR Patent 741 105; 1980

7 E. Wicke and H. Brodowsky, in: “Hydrogen in Metals”, Top. In Appl. Phys., 29, Ed. G. Alefeld and J. Volkl, Berlin, Springer, 1978, p. 73

8 F. A. Lewis, Platinum Metals Rev., 1982, 26, (I), 20; I 982,26, (2), 70; I 982,26, (3), I 2 I

PhYS. W . 3 1982, 25, (81, 596)

9 V. E. Antonov, I. T. Belash, V. M. Koltygin and E . G. Ponyatovsky, Dokl. Akad. Nauk SSSR,

10 M. Stackelberg and P. Ludwig, Z. Natutforsch.,

I I N. S. Scholtus and W. K. Hall, 3. Chem. Phys.,

12 L. D. Landau and E. M. Lifshitz, “Statisticheskaya Fizika”, Moscow, Nauka, 1976 (Engl. Transl.: “Statistical Physics”, New York, Pergamon, 1979)

13 I. A. Yurichev, Teplojzika Vysokikh Temperatur, (High Temperature Thermophysics), 1979, 17, (6), I 187

I 4 H. W. Wooley, R. B. Scott and F. G. Brickwedde, 3. Res. NBS, 1948,41,379

1 5 P. V. Geld, R. A. Ryabov and E. S. Kodes, “Vodorod i Nesovershenstva Structury Metalla”. (Hydrogen and Imperfections of Metal Structure), Moscow, Metallurgiya, I 979

1979,248, ( I ) , 131

I 9647 19a3 93

19635 399 868


Thermophysical Data on Platinum KESIS‘I‘IVITY A N D CONDUCTIVITY VALUES HECOMMENDED

Platinum is one of several key materials whose thermophysical properties such as electrical and thermal conductivities, heat rapacity, coefficient of thermal expansion and diffusivity are used internationally as a basis for calibration and reference purposes. The choice of platinum among this key group of materials (which includes iron, copper, tungsten, silicon and sapphire) is based on its stability and inertness, its ready availability in high purity, its well-established electrical resistance- temperature relationship between I 3.8 and I 2ooK, measured for the International Practical Temperature Scale (IPTS), and the consistency of measurements of thermal conductivity made at several national laboratories over the temperature range 100 to 12ooK.

“Recommended” values of these properties for this group of materials are currently being prepared through the CODATA Task Group on Thermophysical Properties of Solids, which consists of an international co-operation between national laboratories. The recommended values of the electrical resistivity and thermal conductivity of platinum were reported by Guy K. White of the CSIRO Division of Applied Physics, Sydney, Australia, during the conference, “Thermal Conductivity 17”, held at Gaithersburg, Maryland, U.S.A., in June 1983.

Electrical Hesistivity The task of selecting data for platinum has

been made easier because of its role in the realisation of the temperature scale (IPTS) which is defined from 13.8 to 904K. Further efforts to extend the range of platinum resistance thermometers to the gold point ( I 337.6K) has contributed further data. The data have been corrected for factors such as thermal expansion and impurity scattering and fitted to polynomial equations. The recommended values are summarised in the Table as a function of temperature between 20 and

2000K. Resistivity at temperatures below 13.8K is not considered to be sufficiently accurate for recommended values to be assigned. Above this temperature accuracy is considered to be within 0.1 per cent, although only 0.3 per cent above I 3ooK.

T h e r m a l Conductivity The 1972 survey of the data by CINDAS has

been taken as the basis for this study with more recent data at temperatures above I oooK being included. The influence of the purity of the platinum, defined by the average resistance

I t w m n i c d e d ‘I’herniophysical Values

Temperature K

20 40 60 80 100 200 273 300 3 50 400 450 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

Resistivity 10-8Qm

0.03669 0.4038 1 1.1186 1.953 1 2.8040 6.91 69 9.82 10.87 1 12.805 14.712 16.592 18.445 22.070 25.588 28.996 32.292 35.473 38.540 41.50 44.35 47.09 49.74 52.34 54.93 57.51 60.1 1 62.76

Conductivity W/m

47 5 141 95 83 78 72.6 71.7 71.6 71.6 71.8 72.0 72.2 73.0 74.0 75.2 76.6 78.1 79.9 81.8 83.9 86.1 88.4 90.6 (90) 92.7 (90) 94.5 (90) 96.0 (89) 97.4 (88)

Platinum Metals Rev., 1984, 28, (4) 1644165 164

ratio, on the low temperature values has also been examined. This leads to the conclusion that the accuracy of the recommended values lies within 10 per cent below IOOK, but improves to less than 3 per cent between 100

and 3ooK and less than 2 per cent in the range 300 to 12ooK. Above 12ooK accuracy decreases to 1 0 per cent uncertainty. The recommended values are again summarised in the Table; the values above rooK have been corrected for expansion. Those given for temperatures above 16ooK are based on data that leads to values of the Lorenz ratio that are

considered to be too high. More plausible values of the conductivity are given in the Table in brackets, but the author cautions that more measurements in this temperature range are needed.

The conference proceedings of “Thermal Conductivity 17” have been published by Plenum Press, New York, 1983 and readers of Platinum Metals Review are advised to refer to the original paper for a fuller description of the recommended values for both resistivity and conductivity, and for the basis on which they have been derived. C.W.C.

A Report of Fuel Cell Technology The latest briefing of members of The Fuel

Cell Users Group of the Electrical Utility Industry of the United States of America, which took place in Portland, Oregon in July, was designed to provide attendees with a thorough understanding of the status of technology development of the fuel cell. At the meeting it was apparent that, for a number of reasons, the move toward commercial exploitation of fuel cell technology was proceeding at a faster rate than in the past.

Although the 4.8MW phosphoric acid fuel cell power plant in New York is inactive the other demonstration plant built by United Technologies Corporation (U.T.C.), operated in Japan by the Tokyo Electric Power Company, successfully completed Phase I of the programme, that is the generation of 4.5MW of alternating current, in February. The unit ran for roo hours during early June and the Phase 2 endurance test is continuing. While neither has been entirely satisfactory the experience gained has encouraged U.T.C. to proceed to the next stage of development. Twenty-three I IMW units of improved design are to be built and will be offered at competitive prices under guaranteed performance conditions. Additionally, in a programme sponsored by the Gas Research Institute, U.T.C. are manufacturing forty-nine 4okW fuel cells for on-site testing; four by the Department of Defense and the remainder by commercial participants. These phosphoric acid cells incorporate platinum-containing catalysts supplied by Johnson Matthey. To date the longest uninterrupted run has exceeded 75 days, and is continuing. It is important to note that these units are employed under actual working condi-

tions at sites that include a laundry, offices and sports clubs where the combined heat and electric power output, and the environmental acceptability of fuel cells are of great benefit.

The modular construction of fuel cell power plants provided the flexability that will enable the power utilities to respond to changes in the predicted requirements for new and replace- ment generating capacity. The utilities are also seeking plant efficiency and reliability. With this in mind the Westinghouse Electric Corporation has now been given a contract by the Southern California Edison Company to design a 7.5MW fuel cell intended for the utility’s transmission and distribution system.

The meeting was addressed by Mr. K. W. Maxwell, Managing Director of Rustenburg Platinum Mines who spoke of the large reserves that are available to meet the growing market for platinum, and the lead time that is necessary to establish new mining capacity. The known platinum reserves of the Merensky Reef are more than 300 million ounces, while beneath this is another platinum-bearing reef, known as UG2, which also contains in excess of 300 million ounces. It has been estimated that by the year 2000 the demand for platinum to be , used in fuel cells for markets in the U.S.A. and Japan could amount to 580,000 ounces. A major investment of capital and a lead time of I 8 to 30 months would be required to meet this demand. Rustenburg Platinum Mines is closely watching developments to ensure that sufficient platinum is available when it is required.

In view of the useful function performed by The Fuel Cell Users Group in North America, Johnson Matthey have suggested the formation of a similar group in Europe. G.J.K.A.


Catalysts for Sealed Gas Lasers PLATINUM METALS ON TIN OXIDE ENSURE LONG LIFE

By D. S. Stark Royal Signals and Radar Establishment, Ministry of Defence, Malvern, Worcestershire

Platinum group metals, finely dispersed and supported in porous tin (IV) oxide, have been shown to catalyse the oxidation of carbon monoxide gas even at low ambient temperatures. Such catalysts, recently introduced into sealed carbon dioxide TEA (transversely excited atmospheric pressure) lasers developed at the Ministry of Defence Royal Signals and Radar Establishment, have been a crucial factor in the achievement of prolonged operation of such devices.

Carbon dioxide TEA lasers emit ultra-short pulses of infrared radiation, with a wavelength of approximately 10.6 microns, at extremely high peak powers (- I MW) in narrow, nearly parallel beams. Examples of their applications include high resolution range-finding and target tracking. Advantages over conventional laser range-finders using wavelengths close to the visible include much better penetration of smoke and fog and far greater eye safety.

Optical gain in carbon dioxide TEA lasers occurs in a pulsed, uniform electric discharge in a carbon dioxide-nitrogen-helium gas mixture at atmospheric pressure. The difficult problem of generating a uniform discharge at this high pressure, is solved by pre-illuminating the entire active volume with ultra-violet (u.v.) radiation from nearby subsidiary discharges fired immediately before the main volume is energised. Each U.V. pulse uniformly pre-ionises the gas throughout the optical gain region and prevents the development of localised arcs.

For minimum system size, the laser must give maximum peak power output per unit discharge volume. This necessitates operation at the highest possible carbon dioxide concentration, up to 60 per cent of the total gas, which in turn makes it harder to maintain a uniform discharge. Operation in these difficult conditions was only achieved if the laser was con-

tinually flushed through with fresh gas. However, a device for field use must be capable of prolonged sealed operation without gas replenishment. The principal factor preventing this was the dissociation of carbon dioxide into carbon monoxide and oxygen, low concentrations of the latter rapidly degrading the discharge into localised arcs.

Prolonged operation of a sealed, high-carbon dioxide laser was first reported in 1978 (I). In this device a short length of platinum wire at a temperature of approximately I IOOOC continuously catalysed the recombination of carbon monoxide and oxygen. Over 2.5 x 106

pulses were achieved at the modest pulse repeti- tion frequency (PRF) of z Hz.

However, for some applications, such as rapid range-finding, PRFs of about IOO Hz are needed. In such cases, the greater generation of carbon monoxide and oxygen requires correspondingly increased catalyst speeds. In these conditions a hot platinum wire would not only consume excessive power but would also create a cooling problem.

Porous Tin Oxide Supports Clearly, there was a requirement for a

catalyst with greatly increased activity, preferably at ambient temperature, which would eliminate the need for both additional heating power and a cooling system. Other workers have shown that platinum or palladium, very finely dispersed and supported in porous tin (IV) oxide would, at temperatures between 82 and 2oo0C, catalyse the oxidation of carbon monoxide in the presence of a considerable excess of oxygen (2). Their measurements, in entirely different conditions and not directed towards lasers, were made in the absence of carbon dioxide and used 20 per cent oxygen in the presence of 6 per cent carbon monoxide and


74 per cent nitrogen. They showed that the constituents of this combination of stannic oxide and platinum metals acted synergistically, thus activating oxidation rates for carbon monoxide much greater than those due to each component in isolation.

In experiments at the Royal Signals and Radar Establishment several materials including palladiudstannic oxide, platinudstannic oxide and the best commercial catalyst (Hopcalite), were exposed to typical TEA laser gas mixtures at one atmosphere pressure in a sealed vessel (3). Carbon dioxide concentrations up to 60 per cent were used, the balance being nitrogen and helium. The carbon dioxide was then partially dissociated by firing tungsten arcs just long enough to create carbon monoxide and oxygen concentrations of 6 to 8 per cent and 3 to 4 per cent, respectively. The subsequent carbon monoxide and oxygen removal rates and the corresponding carbon dioxide generation rates were determined by mass spectrometry as functions of catalyst temperature, exposure time and partial pressures of the interacting gases. The experiments were performed with each catalyst at a number of different temperatures between 44OC and -27°C; all demonstrated measurable activities.

The best results were obtained with 1.8 weight per cent palladium and 1.3 weight per cent platinum, each supported on stannic oxide, which showed apparent activation energies of 39.7 kJ/mol (standard deviation 6 per cent) and 4 I .4 kJ/mol (standard deviation 5 per cent), respectively. For equal masses, the room- temperature activities were nearly a factor of 70 greater than for the best commercial catalyst. Moreover, unlike the commercial catalyst, which rapidly deteriorated, they retained their activity despite repeated exposure to moist air.

Platinum group metaystannic oxide catalysts have now been successfully used in high-PRF, high-carbon dioxide TEA lasers and prolonged sealed operation of these devices has recently been reported (4). In order to achieve high-PRF operation, a fan drives the hot gases from the electric discharge continuously round a closed loop in which they are cooled before being

returned to the discharge region. During circulation, the gases pass between metal plates coated with platinumgroup metalhtannic oxide catalyst which continuously recombines the carbon monoxide and oxygen generated in the discharge. The catalyst, at an equilibrium temperature up to 5o°C, is unheated except by the hot discharge gases and therefore requires neither additional power source nor cooler.

The laser is sealed with a carbon dioxide-rich gas mixture which is typically 50 per cent carbon dioxide-33 per cent nitrogen-17 per cent helium and provides output peak powers of about I MW. Over 2 x 10' pulses have been obtained from a single gas fill. Operation is mostly at a continuously applied PRF of 30 Hz, or in regularly repeated bursts of loo Hz. By contrast, without the catalyst, the laser discharge consistently failed after only 3 x lo3 pulses, through the rapid accumulation of excessive oxygen. With the catalyst, on the other hand, the oxygen concentration is maintained continuously below 0.3 per cent throughout the test. There has been no evidence of any deterioration of either the catalyst or the gas discharge which would prevent the achievement of much longer lives.

The use of platinum group metaystannic oxide catalysts in carbon dioxide lasers is covered by Ministry of Defence patent rights (5 ) .

Acknowledgements Acknowledgements are due to R.S.R.E. colleagues

including P. H. Cross for laser design work and D. Brumhead for preparation of early catalyst samples. P. Smith of the International Tin Research Institute, London, supplied initial samples and technical information, and A. Holt and M. Cheek of Universal Matthey Products Limited developed supported catalysts under a Ministry of Defence (DCVD) Con- tract.

Copyright 0 Controller HMSO, London, 1984.

References I D. S. Stark, P. H. Cross and M. R. Harris,3. Phys.

2 G. C. Bond, L. R. Molloy and M. J. Fuller, 3.

3 D. S. Stark and M. R. Harris, 3. Phys. E , 1983,

4 D. S. Stark, A. Crocker and N. A. Lowde,J. Phys.

5 D. S. Stark, British Parent 2,028,571B; 1978

E, 1978, 11, (41, 31 I

Chem. Soc., Chem. Commun., 1975, ( is) , 796

16, (61,492

E, 1983, 16, ( 1 I) , 1069


The Chemistry of the Platinum Group Metals A REVIEW OF THE SECOND INTERNATIONAL CONFEKENCE

By B. A. Murrer Johnson Matthey Group Research Centre

Following a successful meeting held in Bristol in 1981, the second international conference to deal entirely with the chemistry of the platinum group metals was held at the University 0.f Edinburgh in July 1984, sponsored by the Dalton Division of the Royal Society of

Chemistry. The conference attracted over three hundred participants from both academic and industrial organisations in twenty three countries. There were twenty seven lectures, and in excess 0.f one hundred posters presented during the week. The lectures are sum- marked here, while a book containing abstracts of the posters only is available from the Royal Society of Chemistry.

Topics covered at Edinburgh included cluster and organometallic chemistry, catalysis, biological aspects and physical methods. The conference was opened by Professor Joseph Chatt of the University of Sussex, who gave his impressions of progress since he first became involved in this field. It was particularly appropriate that Professor Chatt should address the conference as it was he who had organised the first small conference on the co-ordination chemistry of the platinum group metals some thirty five years ago. From that time onwards the interest in their organometallic chemistry has increased enormously, leading to the development of the industrially important area of homogeneous catalysis, to a far greater understanding of cluster chemistry and, more recently, to the successful use of platinum group metal compounds in medicine. His introduction was also enlivened by reminiscences of some of the leading personalities formerly involved in these areas of research.

The first lectures of the conference considered homogeneous catalysis; Professor J. Halpern of the University of Chicago presented the results of his investigations of the mechanism of homogeneous hydrogenation by

anionic ruthenium hydride complexes. The activity of the orthometallated species K+[RuH 2(PPh 3) 2(PPh 26 6H 4)]- in homogeneous hydrogenation was reported in 1980 when it was shown to reduce ketones, esters, nitriles and polycyclic aromatics as well as olefins. Originally this unusual reactivity was ascribed to the hydride groups in the anionic catalyst but Professor Halpern went on to show that this is not the case as for instance, hydrogenation of anthracene to 1,2,3,4-tetrahydroanthracene proceeds via a co-ordinated 1,3diene intermediate. A number of anionic ruthenium hydride phosphine complexes were isolated and all gave the same activity, showing that the original orthometallated complex, formed by ruthenium insertion into the C-H bond of an ortho carbon in a triphenylphosphine ligand, is probably not itself involved in the catalytic cycle. These anionic species decompose with protonic reagents so the hydrogenation of ketones and nitriles, which yields alcohols and amines, respectively, as products is not likely to involve them to any great extent. By examina- tion of single steps, Professor Halpern showed that two catalytic cycles operate with the common intermediate being a solvated form of


[RuH2(PPh3)3]. In the course of this work straightforward syntheses of catalytically active compounds were developed and it is hoped that their unusual selectivity will make them useful laboratory reagents.

Professor B. Bosnich of the University of Toronto discussed his work on metal-catalysed Claisen and Cope rearrangements. These rearrangements are highly stereospecific and widely used in synthetic organic chemistry, but are generally very slow requiring several hours at 2oo0C to go to completion. Such harsh treatment may cause decomposition so a catalysed reaction would be very useful and leads to the possibility of using optically resolved (chiral) ligands on the metal catalyst to achieve asymmetric synthesis. Bosnich screened a number of noble metal complexes and found that [PdC12(PhCN)2] gave a remarkable rate acceleration (reaction complete in a few hours at room temperature) with the same stereochemical control as in the uncatalysed rearrangement. The Pdo complex [Pd(PPh3)4], gave considerable deuterium scrambling but the stereochemistry of the starting material was still preserved. This was explained in terms of a dissociation of the imidate ester starting material (a) to a palladium r-ally1 complex and an amide anion followed by their recombination to give the amide (b).

In conclusion, Professor Bosnich emphasised that Pd"') catalysis can be widely applied in organic syntheses and that further work will be aimed at introducing chiral centres into the products.

In his lecture entitled Reactivity and Selectivity in Catalysis Dr. J. M. Brown of the University of Oxford described some of his more recent work on homogeneous hydrogenation catalysis. Results from model compound studies and NMR evidence suggested that a cis-bis- phosphine rhodium complex could be an inter-

mediate in the hydrogenation of olefins with Wilkinson's catalyst [RhCl(PPh,),]. The asymmetric hydrogenation of olefins with catalysts with chiral ligands to give optically active products was also discussed, with particular emphasis on the use of stable iridium complexes as models for the corresponding transient rhodium complexes which are intermediates in the reaction.

One of the most interesting new develop ments in organometallic chemistry and of considerable potential in commercial terms, is the activation of C-H bonds in saturated hydrocarbons. This was reviewed by Professor W. A. G. Graham from the University of Alberta who then described his own work in the area. In his laboratory the activation of cyclohexane was discovered by accident, as irradiation of a solution of the pentamethylcyclopentadienyl complex [lr(C0)2q5-CsMes] in cyclohexane under hydrogen was expected to give a trihydride, but instead gave a cyclohexyl derivative where iridium had inserted into a C-H bond. The presumed I 6-electron intermediate in this case, either [Ir(CO)qS-CSMes] or [Ir(C0)2q3-CsMes], is so reactive that Professor Graham stated that he has yet to find a hydrocarbon with which it does not react. A similar osmium complex [OsH2(CO)q6-C6Me6] also gave products of insertion in photolysis in alkane solvents, but with some decomposition. Direct conversion of hydrocarbons to functionalised derivatives is possible but a commercially viable system is some way off as yet.

Organometallic Chemistry Professor R. Poilblanc of CNRS, Toulouse

described the synthesis and reactions of iridium and rhodium bi- and trimetallic species where the metal atoms were bridged with sulphur- based ligands and Dr. A. J. Deeming of University College, London reviewed the occurrence of metallocarboxylic acids and their role in the homogeneously catalysed water gas shift reaction (CO + H 2 0 = €I2 + C02). He then presented his work on iridium complexes for instance cis,cis,trans-[IrC12(COOH)(CO) (PPhMe2)2], prepared by addition of methyl


chloroformate to the square planar truns- [IrCI(CO)PPhMe2)2] and subsequent hydrolysis of the ester. In the presence of base, the carboxyl group was lost to give an iridium hydride via an Irl intermediate, and in acid an iridium carbonyl was obtained via protonation of the carboxyl group and loss of water. In his lecture on organic transformations at ruthenium centres Dr. S. A. R. Knox of Bristol University illustrated the conversion of a bridging car- bony1 ligand in a metal-metal bonded diruthenium compound to a bridging methylene ligand. This could then be converted to a bridging methyl group by protonation or to a bridging methyne by hydride abstraction. The bridging methyne ligand reacted readily with alkyllithium reagents to give substituted bridging methylene groups which may possibly be thought of as model compounds for the Fischer- Tropsch reaction on metal surfaces.

Professor H. Werner of the University of Wiirzburg described the preparation of rhodium cyclopentadienyl complexes with small, normally highly reactive organic molecules as ligands. Complexes of thio-, seleno- and telluroformaldehyde were prepared by reaction of NaSH, NaSeH or NaTeH with [RhI(CH21)$CsHs(PMe3)]. With nucleophiles (pyridine, phosphines, sulphides) this compound gave ylid complexes such as [ RhI( CH 2PR 3) r] 'C 5H 5(PMe 3)]+ by attack of the nucleophile on the co-ordinated iodomethyl group. A similar rhodium compound with a co- ordinated vinylidene ligand could be converted to complexes with thioketene and thioace- taldehyde ligands. Professor G. van Koten of the University of Amsterdam described his work on the oxidative addition of alkyl halides to platinum complexes where reversible alkyl shifts from platinum to a carbon atom of the ligand were observed.

Cluster Chemistry The session on cluster compounds was

opened with a lecture by Professor Sir Jack Lewis of Cambridge University who gave an overall view of the cluster chemistry of ruthenium and osmium. Professor Lewis

showed that synthetic methods for homo- and heterometallic clusters are now becoming rationalised, particularly since the introduction of tertiary amine oxides for the stepwise removal of carbonyl ligands. With the aid of molecular models he then demonstrated how clusters can be built up and taken apart to give a wide variety of new metal atom frameworks. Large cluster compounds particularly those containing large proportions of metal atoms may be analogous to bulk metals and Dr. A. Ceriotti of the University of Milan described the synthesis and characterisation of some very large platinum and platinudnickel clusters such as [Pt3n(C0)44H2l2-. Heating this platinum cluster gave a larger cluster which is not yet fully characterised but had a diameter of 20.5A by high resolution electron microscopy, which would correspond to about IOO platinum atoms.

Professor S. G. Shore from Ohio State University presented his results on the synthesis of the anions of ruthenium carbonyl clusters and discussed their relevance in catalysis of the water gas shift reaction. Treatment of [ R u ~ ( C O ) ~ ~ ] or [H4Ru4(CO)12] with potassium hydride or an alkali metal together with benzo- phenone gave high yields of anionic clusters, the structure of which could be altered by varying the stoichiometry. Reaction of these anions with clusters of other metals gave mixed metal clusters. Catalysis of the water gas shift reaction by anions containing four ruthenium atoms did take place but the overall reaction was extremely slow (approximately 3 turnovers per day at IOOOC under 0.9 atm carbon monoxide). The activity could be improved slightly by the addition of chelating biphosphines. This could be a true example of catalysis by an intact cluster, as the mononuclear anion [HRu(CO)$ does not survive the reaction conditions.

The synthesis of mixed metal clusters containing palladium and platinum by reaction of square planar d n trans-dichloro complexes containing a variety of ligands with a number of sodium carbonylmetallates such as Na[Mn(CO)s] was described by Dr. P. Braunstein of the Universitk Louis Pasteur,


Strasbourg. A mixed metal cluster [PdzMozCp~(CO)a(PPh3)~1 on a support of alumina gave an active and selective catalyst for the carbonylation of nitrobenzene to phenylisocy anate.

Heterogeneous Catalysis The importance of the surface topography of

a supported catalyst and the state and effect of adsorbed hydrocarbons was discussed by Dr. G. Webb of Glasgow University in his lecture entitled “Transformations of Hydrocarbons Catalysed by Platinum Group Metals”. Dr. Webb described the two extreme types of reactions: those which are structure insensitive, such as olefin hydrogenation where the catalyst dispersion and type of support have little effect on the activity per metal atom and those which are structure sensitive such as hydrogenolysis where more than one metal site is believed to be involved. He then described some of his recent work which showed that in the hydrogenation of ethylene with a palladiudsilica catalyst the surface is rapidly and irreversibly covered by a monolayer of carbonaceous material which is not itself hydrogenated. There is a growing body of evidence that for most reactions of hydrocarbons the catalyst surface is almost completely covered with an organic layer which has a significant effect on catalytic activity. The exact role of this layer is not yet defined but in some cases it acts as a slow poison, perhaps due to graphitisation, whereas in other cases it dramatically enhances the catalytic activity. The layer may also act as a hydrogen reservoir or even as an electron donor, hence lowering the work function of the metal. In conclusion, Dr. Webb stressed that the organic layer is a vital part of a catalyst and that models used for supported catalysts should take account of this monolayer coverage of carbonaceous material.

Dr. B. Harrison of the Johnson Matthey Group Research Centre in his lecture on the preparation of noble metal catalysts began with a survey of uses of heterogeneous platinum group metal catalysts and pointed out that the amount of noble metal used in pollution control systems, particularly catalytic converters on

automobiles, will soon exceed that used for catalysis in the petrochemical industry. He then illustrated the importance of selecting the correct catalyst precursor in the preparation of supported metal catalysts and the relevance of the control and understanding of the firing procedure to obtain the required dispersion. Dr. Harrison concluded with a description of two applications of catalyst technology, automobile emission control and fuel cells, where a deep understanding of the catalyst preparation is necessary in designing and developing a successful catalyst.

Photolysis of Water In his lecture on platinum group metals and

the photodissociation of water, Dr. A. Harriman of the Royal Institution reviewed the different approaches to water photolysis and commented that there has been a recent slackening of interest in this area although the problems are by no means solved. He then went on to describe his work with metalloporphyrins as stable photosensitisers which absorb in the visible spectrum and can be readily modified. During a hydrogen evolution catalysis test an aqueous solution of a zinc metalloporphyrin with methyl viologen and EDTA as hydrogen donor gave 200ml hydrogen per hour from one litre of solution on the roof of a building in London. Metalloporphyrins were also successfully used as redox catalysts in the oxygen evolution reaction.

Dr. D. J. Cole-Hamilton of the University of Liverpool discussed his recent work on low valent platinum complexes, especially [HPt(PEt 3)3]+. Ultraviolet irradiation of a solution of this complex in dilute sulphuric acid leads to the catalytic production of hydrogen, together with the formation of persulphate. Silver ion catalyses the decomposition of persulphate to oxygen and sulphate, giving catalytic water photolysis. The disadvantages with this system are that it requires U.V.

illumination and the turnover number is very low. A similar platinum complex [PtHCl(PEt&] was shown to be active for the conversion of glucose to hydrogen and carbon dioxide in


alkaline solution and this may have potential uses in conversion of waste carbohydrate.

Medical Uses of the Platinum Group Metals

The increasingly important use of the platinum group metals in medicine was comprehensively covered in three lectures. Dr. E. W. Stern of Engelhard Industries gave an overview of their applications. In addition to the well known use of platinum compounds in cancer chemotherapy the radioactive isotope 1921r may be used in radiotherapy, when a small amount of the metal inside a plastic tube is placed inside or close to a tumour. The dose of radiation is then contained within a small area, minimising damage to the patient and increasing the safety of medical personnel. Another iridium isotope is used in autoradiography. In this case I9OOs is irradiated with neutrons to give l9IOs which is then converted to [0sCl6l2-. A solution of this relatively long-lived isotope is injected into the patient where the short-lived decay product 191mIr (t+=4.9 s) emits y- radiation which is detected in autoradiography. The highly toxic OsO4 has a surprising use in treatment of inflammatory arthritis of the knee. A solution of the reagent is injected into the knee where some precipitates as insoluble oxides. This gives relief of pain and swelling in 60 to 70 per cent of patients with few side effects. The treatment has been used in Sweden and Norway since 1978. Dr. Stern concluded with a list of potential medical uses for platinum group metals as a variety of compounds have been shown to be effective as radiosensitisers, antiviral and antiparasitic agents and bacteriocides.

Dr. P. Sadler of Birbeck College began with a summary of the metal compounds which have been tested for antitumour activity by the National Cancer Institute. Of 13,000 compounds tested (remarkably few compared with the number of organic compounds screened) about one thousand were active. Of these, thirteen platinum complexes have entered clinical trials but there are indications that ruthenium complexes may also be effective with

about 20 per cent of the compounds tested showing some activity. The characterisation and some reactions of two of the latest platinum drugs in clinical trials, Carboplatin UM8, diammine-I, I -cyclobutanedicarboxylato- platinum(II)] and Iproplatin UM9, cisdichloro- trans-dihydroxo-bis(2 - aminopropane)platinum (IV)] were then illustrated followed by a description of the preparation of platinum complexes with nitroimidazole ligands for use as radiosensitisers.

Carboplatin

Iproplatin

Dr. H. Calvert of the Institute of Cancer Research gave a clinician's eye view of the development and use of platinum complexes in cancer chemotherapy. He described the remarkable results obtained with Cisplatin [cis- diamminedichloroplatinum(II)] in the treatment of testicular cancer and its uses against other types of cancer. However, the major side effects of this drug, nephrotoxicity and prolonged nausea and vomiting, limit its use. Two second generation drugs, Carboplatin and Iproplatin, developed in conjunction with Johnson Matthey Research are currently being evaluated as less toxic analogues. Carboplatin is being used at the Royal Marsden Hospital in single agent therapy for advanced ovarian cancer in a randomised comparison with high dose Cisplatin. Results to date show equivalent activity with greatly reduced side effects, particularly elimination of kidney toxicity and hearing loss and reduced nausea and vomiting. Iproplatin which is being used for the treatment of ovarian cancer at the Christie Hospital,


Manchester is showing similar results though with slightly greater toxicity than Carboplatin. Additional trials of Carboplatin at the Royal Marsden Hospital suggest that its reduced toxicity will allow platinum therapy to be used for a'wider range of cancers, where results for small cell lung cancer has been promising.

Physical Techniques Three lectures illustrated the use of NMR to

solve a wide variety of problems in platinum group metal chemistry. Professor J. W. Faller of Yale University described a novel method of determination of the structure of palladium Z-

ally1 complexes by NMR spectroscopy of complexes with a paramagnetic, encapsulated Coz+ ion incorporated into a phosphine ligand. The use of high pressure NMR in the determination of rates of solvent and electron exchange reactions of platinum group metal solvates was discussed by Professor A. E. Merbach of the University of Lausanne. Dr. C. A. Fyfe of the University of Guelph, Ontario reviewed the theory of high resolution solid state NMR, a technique of rapidly growing importance in diverse areas of chemistry. The use of solid state NMR was illustrated with a study of supported homogeneous catalysts, where phosphine ligands could be shown to be almost fully oxidised, and hence become inactive, during some methods of catalyst preparation.

Dr. J. A. Harrison of the University of Newcastle-upon-Tyne began with a summary of electrode kinetics and went on to describe the range of instrumental methods available to investigate the electrode reactions of inorganic compounds and electrocatalysis on electrodes based on platinum group metals. The technique of resonance Raman spectroscopy was described by Professor R. J. M. Clark of University College, London and its use illustrated in the study of mixed valence platinum chain compounds. Dr. J. Evans from the University of Southampton in his lecture on the role of EXAFS (extended X-ray absorption fine structure) in platinum group metal chemistry showed how this technique could be used to

determine the distances of atoms from a central metal atom. Examples were given from homogeneous catalysis (the orientation of ligands in a rhodium catalyst for asymmetric hydrogenation), heterogeneous catalysis and surface science. One of the strengths of the technique is that samples may be solid, in solution, on a surface or even in the gas phase. Professor N. Sheppard of the University of East Anglia discussed the use of vibrational spectroscopy to characterise metal surfaces and its relevance to the study of noble metal catalysts on oxide supports. Two recent developments have greatly aided work in this area: Fourier transform and computing techniques and electron energy loss spectroscopy. By a combination of these techniques and comparison with model metal cluster compounds, Professor Sheppard was able to show that the major species resulting from ethylene adsorption on platinudsilica have one carbon atom bridging two or three metal atoms.

The use of thermodynamics in the extraction and refining of the platinum group metals was discussed by Dr. J. R. Taylor of the Johnson Matthey Group Research Centre. The various processes were presented as far as possible in thermodynamic terms, relating the process reactions to the basic thermodynamic properties of the platinum group metals and associated minerals. Refining was discussed in terms of a possible hydrometallurgical route, and the smelting and converting operations, where ways of modelling the complex matte phase using thermodynamic data based on the component binary systems, were described.

The talks at the conference provided an excellent overview of the current state of knowledge in platinum metals chemistry, and the posters gave an opportunity for presenta- tion of very recent results. The high concentration of academic research in this area is reveal- ing opportunities for more commercially orientated work particularly in the area of catalysis. Representatives from academia and industry from many different parts of the world were able to discuss their mutual interests, and subsequent collaborative work is likely to result.


High Temperature Durability Trial THREE-WAY PLATINUM METALS CATALYST COMPLETES 50,000 MILES AT MAXIMUM VEHICLE SPEED

By A. J. J. Wilkins Johnson Matthey Chemicals Limited

During July 1983 the Government of the Federal Republic of Germany tabled proposals to introduce legislation effective from January I 986 that would, in practice, require three-way catalysts to be fitted to gasoline-fuelled automobiles for the control of hydrocarbon, nitrogen oxide and carbon monoxide emissions. It was stated that to facilitate this objective unleaded fuel would be made available. Although catalysts for this purpose are already in production for use in the United States of America and Japan it was suggested that they might not be entirely suitable for European applications. This was because catalysts fitted to European vehicles could be subjected to long periods of high speed driving, producing high temperature exhaust conditions which would be a very severe test of catalyst durability.

Johnson Matthey Chemicals Limited have now completed a 50,000 mile high speed durability trial with a United States specifica- tion vehicle fitted with a three-way catalyst to determine the extent to which the catalyst deactivated under such conditions. At the end of the trial the emission levels were still within the California 1983 model year limits, that is less than 0.41, 0.7 and 7.0 grams per mile of hydrocarbons, nitrogen oxides and carbon monoxide, respectively.

The test vehicle was a 1.8 litre Volkswagen Scirocco tuned to meet California 1983 model year emission limits, the fuevair supply being controlled by an oxygen sensor feedback system (Bosch “K” jetronic). A Johnson Matthey three-way catalyst of standard production size but specifically designed for high temperature operation was fitted. The catalyst which contained platinum and rhodium in the ratio of 5 : I was deposited on a ceramic monolith support at a loading of 40 g per cubic foot. A

similar imitation unit which did not contain noble metals was used to obtain baseline emissions from the vehicle.

The trial was conducted by the Motor Industry Research Association (MIRA) on their high speed durability track at Nuneaton, Warwickshire, England, between November I 983 and April I 984. The vehicle was operated at its maximum speed of 105 m.p.h. for the majority of the trial with short low speed, low temperature periods during refuelling stops. Continuous recordings were taken of the inlet and outlet temperatures to the catalyst, exit temperatures ranging between 930 and 950°C for most of the trial. This meant that catalyst mid-bed temperatures were as high as 950 to I ooooc.

As this trial was designed to test the high temperature durability of the catalyst the gasoline used contained very low levels of lead (< I mg/l) as specified for the United States, and as a result catalyst poisoning was negligible.

Catalyst Performance During the trial the performance of the

catalyst was assessed by both the current U.S. test procedure, that is the FTP7S test (German Government proposal) and the ECE-15 test (current European test) at zero, 5,000 and 10,000 miles, and at 10,ooo mile intervals thereafter. At each test point the baseline emissions of the vehicle were checked by removing the catalyst and substituting the imitation unit. In all cases sufficient catalyst and baseline tests were conducted (normally two) to ensure the results were consistent. Normal servicing proce- dures as laid down in the manufacturer’s handbook were followed throughout the trial.

The results from the trial were extremely encouraging. Data for the FTP75 and ECE-15


Ttemperatures than those used in the U.S.A., where maximum speed limits are in force. To establish catalyst high temperature durability, the Motor Industry Research Association has conducted high speed trials on their test track a t Nuneaton, where a Volkswagen Scirocco fitted with a Johnson Matthey platinum-rhodium three-way catalyst has successfully completed 50,000 miles, mostly a t a speed of 105 miles per hour

tests are sumrnarised in Table I and Table 11, respectively. During the FTP75 test the emissions exceeded the limits at some points but this was usually caused by faults in the control

system and at 50,000 miles all the emissions were within the California limits, see Figure 2.

Deterioration factors were calculated at 2.02 for hydrocarbons, 2.52 for nitrogen oxides and

Mileage

0 5,000

10,000 20,000 30,000 38,000 50,000

For. comparison

Table I

Catalyst Performance in the FTP75 Test

Average emissions, grams per mile Conversion efficiency, per cent

HC NO, co HC NO, co

0.29 0.1 5 3.59 82 95 78 0.1 7 0.20 3.19 92 92 82 0.2 5 0.1 7 3.48 85 94 79 0.23 0.3 1 4.39 85 88 73 0.51 0.37 5.86 73 85 68 0.50 0.48 6.20 71 80 65 0.41 0.46 5.01 73 72 69

0.4 1 0.7 7 .O California 1983 model year limits


Fig. I Emission control catalysts for use in Europe are likely to be subjected to higher exhaust

I Fie. 2 Exhaust emis-

Mileage

0 5,000 10,000 20,000 30,000 38,000 50,000

For. comparison

$o,61 Carbon monoxide

\

Average emissions, grams per test Conversion efficiency, per cent

HC NO* co HC NO* co

0.79 0.08 5.20 88 98 88 0.72 0.66 6.05 92 85 88 0.96 0.40 7.27 88 90 86 0.88 0.58 6.43 87 86 84 1.60 0.67 14.40 87 81 66 1.78 0.99 1 1.23 75 77 74 1.60 1.03 10.78 76 64 76

15.0 Narjes proposal fin

ISDg

-"- fo 2 ~ / ~ t i y d r o c a r b o n s

E 5 Nitrogen oxides

4 .2.0"

1 I 5,000 lob00 20,000 30.000 4 W O O 50,000

MILES

as a function of mileage, the lines being drawn through mean values of stable test points. The 1983 Californian limit for the three emissions are indicated by the appropriate broken horizontal line

I .zz for carbon monoxide; although higher than those obtained with catalysts destined for the U.S. market (normally 1.0 to 2.0) these figures are considered to be good, bearing in mind the operating conditions. Likewise catalyst conversion efficiencies were acceptable.

Emissions during the ECE-15 test were also very low. Exhaust temperatures in this test are lower than during the FTP75 cycle, and therefore it is a good measure of the activity of a severely aged catalyst. One of the most severe proposals for European vehicles has been suggested by Narjes, and would restrict hydrocarbon plus nitrogen oxide emissions to 6

grams per test, and carbon monoxide to 15 grams per test. At 50,000 miles all three emissions were within these limits.

The successful completion of this trial has demonstrated that modifications made to the technology currently used for the production of three-way catalysts have resulted in a catalyst capable of withstanding temperatures of 950 to iooo°C for very prolonged periods. It is con- fidently predicted that this technology, together with further improvements in catalyst design which are now being made, will enable platinum group metal autocatalysts suitable for all European driving conditions to be produced.

Table II

Catalyst Performance in the ECE- I5 Trsl

176

sion levels during the FTP75 test are dotted

A Valuable Review of Ruthenium T h e Chemistry of Ruthenium, Topics in Inorganic and General Chemistry 19 BY ELAINE A. SEDDON AND KENNETH R. SEDDON, Elsevier, Amsterdam and New York, 1984, I 374 pages, Dfl. 650.00 (approx. $250)

The scope of this new monograph covers the coordination chemistry, organometallic chemistry, structural chemistry, spectroscopy, kinetics, electrochemistry and photochemistry of ruthenium, and particular emphasis is placed on synthesis and structures reflecting the approach of many modem inorganic chemists. The book deals with literature from 1804 to 1978 and updates the excellent account “The Chemistry of the Rarer Platinum Group Metals” by W. P. Griffith published in 1967. The need for such a work is reflected by the fact that Griffith’s text contained 400 references whereas this volume has almost 4,000. It aims to cover the literature comprehensively.

In the introduction the scope and organisation of the book are defined and the history, extraction, properties and applications of ruthenium are dealt with briefly. The following chapter addresses the concept of oxidation state. The vagueness and inadequacies of formal oxidation state are discussed critically and a new scheme, the MLX concept for systemising descriptive inorganic chemistry, which has been developed by Drs. M. L. H. and J. C. Green at Oxford is defined and applied to ruthenium. The advantages and limitations of this scheme are described concisely. It is appropriate that oxidation states are discussed in some detail as the text is structured around this concept.

The chapters dealing with individual oxidation states of ruthenium are organised such that the reader may rapidly access details or references on a specific compound. Each section is subdivided into synthesis, simple properties, structure, spectroscopic properties, reactions and electrochemistry. The reader is also aided by the inclusion of classified tables which list the compounds and their salient physical properties. The discussion is concise and interesting with unusual features clearly highlighted and well presented.

In the chapter on ruthenium(II1) the nature of ruthenium trichloride is discussed in sufficient detail to aid the synthetic inorganic chemist. Another highlight of this 180 page section is the critical discussion of the controversy surrounding the electronic structure of p-pyrazine-bis[penta ammine ruthenium(I,II)] salts.

The mammoth task of clarifying the diverse chemistry of ruthenium(I1) occupies 5 50 pages. The authors attempt to stress important areas such as penta ammine(dinitrogen)ruthenium(II) and 2,2’-bipyridine and I, I o-phenanthroline complexes of ruthenium(I1). In the latter case there is a useful discussion of the different synthetic methods that have been employed. Relatively new areas such as carbene complexes are also described.

Recent reviews relating to the chapters on ruthenium carbonyl clusters and ruthenium nitrosyls have been published and sections in the book aim to complement these. The final chapter is devoted to the photophysics and photochemistry of [Ru(bipy)#+ and related complexes, which is justified because of the importance of the photocatalytic decomposition of water. However, it was disappointing that the authors did not develop the topic of homogeneous catalysis more fully. It is difficult to gain an insight on the considerable research effort devoted to this field without reading the primary literature.

Although an extensive review on the organometallic chemistry has recently appeared (in Comprehensive Organometallic Chemistry, I 982), this authoritative and instructive review deals with the full chemistry of ruthenium and, overall, will provide valuable aid to synthetic inorganic chemists who wish to get an appreciation of ruthenium complexes. The organisation of the book is such that the text will form a valuable reference source. M.J.H.R.


Platinum and Early Photography SOME ASPECTS OF THE EVOLUTION OF THE PLATINOTYPE

Ian E. Cottington The Johnson Matthey Group

The stability of platinum was well known, and the light sensitivity of

some of its salts had been studied, long before a practical photographic process was available. Early photographic prints based upon silver salts lacked permanence, however, so alternatives were sought and eventually a much improved process using platinum was evolved. These platinotype prints became very popular around the turn of this century but the non-availability 0.f platinum for this application during the First World War resulted in the virtual disappearunce o,f the process f rom commercial photography. This article considers some of the work and just a ,few o,f the many people who contributed to the success of the platinum printing process which, fortunately, is still practised by a small number of creative enthusiasts.

Just over one hundred years ago in 1883 Their booklet “Die Platinotypie” had been Captain William de Wiveleslie Abney, published in Austria in the previous year and ( I 843-1 920) rendered a considerable service to because of the theoretical and practical photographers throughout the English speaking importance of the subject the Photographic world by publishing in the journal of the Society obtained the English copyright (2). The Photographic Society-later to become the Royal Photographic Society of Great Britain- a translation of an award winning dissertation by two Austrian army officers, Captain Josef Pizzighelli and Baron Arthur von Hub1 (I).

When “Die Platinotypie” was first published in Vienna it included an original platinotype frontispiece, measuring 4 x 4.5 inches, produced from a negative taken by the court photographer Victor Angerer (4). In addition to the English translation serialised in The Photographic Journal, and reprinted three years later as a brochure ( 5 ) , the dissertation was also translated into French and published in Paris in 1883 (6); unfortunately it appears that none of these versions included the platinotype frontispiece reproduced here


Austrians first gave a very brief survey of some of the early work on the light sensitive properties of some platinum salts. They then went on to describe the use of these salts in photography, including their own notable contribution to the advancement of platinum printing, because

“by our researches we hope to have brought within the reach both of the amateur and the professional photographer a process of reproduc- tion which, in our opinion, as regards the phenomena of printing as well as the artistic effect of the results, is a most important one.” (3)

Their work was both important and timely and “it was undoubtedly due to the publication of this translation that platinotype printing was very much popularised. In proof of the accuracy of this opinion, every following photographic exhibition showed an increasing number of exhibits in platinotype.” ( I )

However the key person in the development of the processes they described was William Willis, junior, of Rromley, Kent, England.

By 1883 photography had already passed through many stages of increasingly successful

Platinum Metals Rev., 1984, 28, (4)

development and utilisation; and although the word photography had been used only since 1839 the action of light, or more correctly radiant energy, upon specific metal salts had been observed several decades earlier. While it is neither practical nor necessary to give here a full account of all the work that contributed to this progress it is perhaps worth noting some of the more significant observations and experiments, particularly those carried out by workers who also aided the growth in the knowledge of platinum,

In the year 1763 Dr. William Lewis, one of the earliest researchers on platinum and the author of a book containing the first authoritative and comprehensive work on the history and properties of platinum (7), repeated and extended work carried out many years earlier by Johann Heinrich Schulze (1687-1744) who in 1727, when professor of medicine at the University of Altdorf near Nuremburg, published his discovery that a particular silver salt was sensitive to light. When Lewis died in 1781 his notebooks relating to this work were bought by the potter Josiah Wedgwood. At the same time Alexander Chisholm, who had been

When their dissertation was published Captain Josef Pizzighelli (1849-1912) was head of the army photographic department in Vienna. Although he was transferred shortly afterwards he eontinucad with his work to improve platinum printing paper. He retired I‘rom the army in 1805, w i t h the rank of cdonel and moved t o Florc-nce whew he hwame presidenl o f the Society Fotographica Italiana. A t the time Baron Arlhur von Hub1 ( I I W - 1932) was an artillery offiwr study- ing chemistry at the technical c*ollege in Vienna, where J o s e f Mar ia Ei1t.r ( I t i 5 5 - 1 9 4 4 ) gave lecturc.s i n photochemistry. Hiibl later became a field marshall and head of the Austrian Military Geographical Institute.

179

Lewis’s assistant since about I 750, entered service with Wedgwood as chemical assistant and tutor to his fourth son Thomas. As is well known, in 1802 Thomas Wedgwood, together with Humphry Davy, published a method of reproducing drawings on glass with silver nitrate or chloride. This was a major contribution to the advance of photography and it seems very probable that Wedgwood would have known of the earlier work by Schulze, with Lewis providing the link.

In the meantime, in 1776, Torbern Olof Bergman ( I 7 3 y 1 7 8 4 ) professor of chemistry at the University of Uppsala, and perhaps best known to readers of this journal for proposing the name platinum for the element previously known as platina (8), discovered the light sensitivity of silver sulphate and oxalate (9).

Light Sensitive Platinum Salts A number. of people were now investigating

photochemical reactions, including the German pharmacist and chemist Adolph Ferdinand Gehlen, who also conducted detailed experiments on mercury-platinum alloys during the Chenevix/Wollaston controversy over the nature of palladium. l‘he first reference to the light sensitivity of the compounds of platinum, and of uranium occurred in a summary of Gehlen’s experiments published in 1804 (10).

Adolph Ferdinand Gehlen 1775-181 5

A notable contributor to chemistry, Gehlen held the chair of chemistry at the Munich Academy of Sciences from 1807 until his death from arsenic poisoning in 1815. During the period 1803 to 1810 he edited the journal Neues Allgerneines Journal der Cheniie, later Journrtl j i ir Chernir und I’hynik then Journctl fiir Chernie, Physik, und Mineralogie. It was in the first of these titles that he published an account of his investigations on the decomposition by lighl of metal chlorides, including platinum chloride dissolved in a mixture of ether and alcohol. This is the first known report of the light sensitivity of a platinum salt

As well as being greatly involved in the investigation of the catalytic properties of platinum the celebrated chemist Johann Wolfgang Dobereiner ( I 780-1 849) was also engaged in photochemical researches. In I 826 he reduced platinic chloride from its solution by the action of light, and two years later he described the light sensitivity of platinum chloride in an alcoholic solution, and of sodium platinum chloride mixed with alcohol and caustic potash. His observation of the light sensitivity of ferric oxalate was later to contribute significantly to the development of platinum printing for he appreciated that platinum chloride together with oxalic acid forms metallic platinum in light. Additionally he reported that the brown solution of sal- ammoniac of iridium is light sensitive when mixed with oxalic acid ( I I).

In the summer of 1832, Sir John F. W. Hers- chel ( I 792-1 87 I), made public remarkable facts that he had observed “nearly two years ago”. In a letter to Dr. Daubeny, read before the British Association at Oxford on June 22, 1832, Hers- chel reported that if a solution of platinum with


aqua regia had the excess acid neutralised with lime and was then cleared by filtration, no significant precipitation took place when additional lime water was added provided the mixture was made and kept in the dark. However, when it was exposed to sunlight, or even cloudy daylight, a copious white or pale yellow precipitate formed. This reaction was confined tc, the violet end of the spectrum and could be prevented by shielding the solution with red or yellow liquid filters ( I 2).

It is well-known that Herschel enquired into many branches of science, and it has been reported that his chemical experiments with platinum commenced when he came across an old crucible of platinum salts left behind by Sir William Herschel, his father (I 3). However, despite the significance of his work with platinum the son’s greatest contribution to photography was probably the introduction of hyposulphite of soda as the first practical agent for fixing photographic images.

Although Herschel is remembered principally as an astronomer and as such was involved in examining improved optical glass produced in platinum containers by Michael Faraday, he was also a very skilled investigator of photochemical reactions. In 1844, when Robert Hunt (1807-1887) published his “Researches on Light”-laimed to be the first history of photography-he acknowledged the generous assistance that he had received throughout his enquiries from Herschel (14). At the time Hunt was Secretary to the Royal Cornwall Polytechnic Society, and one of the leading photographers of the day. Later he returned to London where he held a number of important appointments, including the Chair of Experimental Physics at the Royal School of Mines, and he was one of the distinguished scientists who in 1879 proposed George Matthey for election as a Fellow of the Royal Society. Hunt was probably the first person to try to utilise the light sensitivity of platinum salts to produce a paper printing process and in his book-where he used the term PLATINOTYPES-he described his early experiments, many of which were to serve as the basis

of study by later workers. However neither his work with platinum nor that of Herschel resulted in a workable process.

Platinum Toning As early as 1840 gold had been used for

toning camera-produced images, greatly enhancing their appearance and also improving their permanence ( I 5). Possessing somewhat similar properties it is not surprising that in time platinum was also considered for this purpose. As far as is known the Frenchman Ernest de Caranza was the first to publish a method of toning positive photographs with platinum, this being in February 1856. His work was reported in several journals ( I 6) and just weeks later on April 21st a letter from Edward C. Cortis describing an alternative process appeared in the Journal of the Photogra- phic Society, of London.

During the late 1 8 ~ 0 s and 1860s platinum images toned by processes the same as or similar to that of Caranza were being produced by many workers. Only two of these will be considered here. First, Charles John Burnett ( I 820-1 907) a Scot who belonged to one of the oldest families in Aberdeenshire, although he was described on patent applications as a gentleman of 21 Ainslie Place, Edinburgh, the city where he spent much of his early life. Secondly Robert Sellon Sellon (I 832-1 877) a military engineer who served for most of his life in India.

Burnett is credited with being the first person to exhibit prints produced using platinum, this being at the British Association meeting held in Aberdeen in 1859. A newspaper report of the final day of the meeting, Wednesday 21st September, from Section B-Chemical Science, President Dr. Daubeny, records that

“Mr. C. J. Burnett showed some specimens illustrating the use of platinum in photography.” (17) Evidently an enthusiastic experimenter,

Burnett was described as “one of the sub- discoverers in the art whose names would be imperishable in the annals of photography” ( I 8) and, indeed, several of his contributions are still


recorded in the standard text on the history of photography (19). For a period he was also a prolific writer to the photographic journals, submitting both articles and letters to the editors. In doing so he engaged in a certain amount of argument and disagreement as to what he had discovered, and where and when his work had been reported or exhibited. Certainly in 1859 he was writing authoritatively on the toning of prints with platinum and palladium (20), while he considered that “the salts of rhodium, iridium and ruthenium, also deserve trial in this way” (21). It is apparent that Burnett was one of the leading contributors to the advancement of the use of platinum group metals in photography. However, until an exhaustive study can be made of his life and work it is perhaps sufficient to quote an assessment from a book written much nearer the time by two recognised authorities on photography:

“It is difficult to know exactly what merit is to be assigned to Burnett; his papers are very numerous, and it is not easy to distinguish actual experiments from mere suggestions. However, it is quite evident that in 1857 he had endeavoured to tone silver prints with platinum and showed prints so toned in 1855. This fact gives him priority over Caranza, although his paper, not having been published until 1857, somewhat militates against this claim. Anyway his uranium experiments developed with platinum, taking the date at 1859, when they were published, although they are stated to have been produced in 1857, and shown in the same year, gives him priority over De Luynes and St. Victor. . . .

“Lastly, as the proposer of, if he did not actually use, the platinous salts, both for silver toning and developing prints in uranium, Burnett merits considerable kudos. It is, indeed, remarkable how near he came to discovering a really practical platinum process, namely, the Willis’ platinum in the bath process. Burnett used ammonio-ferric oxalate, and fixed the ammonio oxalate; and he knew that platinum salts acted as developers of paper so prepared. If only, instead

.

Whether he continued his interest in photography during this period, or later in life when he returned to Aberdeenshire is not known.

An Explanation of the Contribution from India

A short list of people who had worked on the indirect production of platinum images, by treating silver prints obtained in the normal way with solutions of platinum, was given in “Die Platinotypie” and supported by references. Two of these occurred in I 864 in the same issue of The Photographic News, a weekly journal that recorded progress in photography, and the first item reads, in part:

“We have before us a very interesting series of prints, illustrating a series of experiments undertaken to test the value of several other easily reducible metals, besides gold. The metals used were platinum, rhodium and iridium alone, and combined with each other, and with gold. The experiments were undertaken by Captain Sellon, whose residence in India prevents the ready reference we should have desired to enable us to state many particulars at present unexplained. The form of salt used in each instance was a sodiochloride of the metal, so prepared for convenient exportation . . .” (23).

By this time British army engineers in India were including photographic apparatus among their scientific equipment (24). In addition, the first photographic society in India had been founded in Bombay in 1854 and an early issue of a journal produced by this society contained a communication from London reporting that

“M. Ernest de Caranza has communicated to the Academy of Sciences at Paris a novel method, or rather a novel application of a chemical substance in the toning of positive photographs, namely the chloride of platinum. He states that the colours produced by a bath containing this substance are most beautiful.” ( 2 5 )

It seems reasonable to suppose that this information would have become known to those in Bombay who were interested in photography.

of wandering Off into experiments with nearly every known and unknown salt, he had stuck to and perfected this one process, it cannot be doubted that the present platinotype process

One of the first objectives of the Photographic Society of Bombay was to attempt to overcome the difficulty of obtaining Pure chemicals (26). _ _ -

must have been forestalled for many years.” (22) It may therefore seem surprising that in such a Not only did Burnett “wander off into situation Sellon was able to experiment with the

production of platinum photographic images. However, it is now suggested that close family

experiments”, he also left Scotland for many years to undertake sheep farming in Australia.


links would have enabled him to overcome his relative isolation from other workers in Europe, and would have provided him with the materials he required.

When Percival Norton Johnson, the founder of the firm that later became Johnson Matthey, required additional capital to support his gold refining business he was able to obtain a sub- stantial sum from a brother-in-law, William Richard Baker Smith, who thus gained not only a financial interest but also the right to introduce his sons into the business. William R. B. Smith was a naval officer who had served with great distinction in the Napoleonic Wars and in 1847, on being nominated the heir of a maternal aunt, Sophia Sellon, he and his family assumed his mother’s maiden name. By his second marriage he had eleven children and his three oldest sons by this union, Richard Edward Gore, Percival and Robert Sellon all served in India. However, it seems that the only soldier in India with the surname Sellon to rise above the rank of lieutenant was Robert Sellon Sellon, who was in India between 1852 and 1877, initially as an officer in the Bombay Corps of Engineering. He spent much of his time in public works and held the rank of captain during the period from 1858 to 1870 (27). Adaughter recalled that her father was “one of the pioneers of wet plate photography” and that some 70 years after his death “his pictures after all these years show very little fading” (28). There can be no doubt that he was the Captain Sellon experimenting with the use of platinum salts for photographic purposes.

Meanwhile in London Commander William R. B. Sellon had introduced his fourth son Frederick into the business, but this young man died shortly afterwards, in I 850. The following year his place was taken by the next son, John Scudamore Sellon, who in 1860 became a partner in Johnson Matthey which by then had been involved with the platinum metals for almost half a century.

In July 1855 Robert Sellon Sellon was married in Karachi to Harriet, a daughter of Captain Thomas A. Souter, and four years later Robert’s brother John Scudamore Sellon

married Harriet’s sister Fanny Maria, in London. Thus it is suggested that the probability of regular communications between the two brothers, one a major supplier of the platinum metals in London and the other a potential user in India, was increased. Indeed it is evident that the ties between these two branches of the family were maintained for, in time, one of Robert’s sons and two of John’s were to become directors of Johnson Matthey. In addition another of Robert’s sons, Ernest Marmaduke Sellon became a director of Johnson Matthey & Company Incorporated, a small platinum marketing company established in New York in July I 9 I 9.

The Work of William Willis Using toning processes it was possible to

apply platinum photographic images to glass or porcelain, where they could be fixed by a lead containing flux, but platinum toning never found any general photographic application. Indeed, no practical platinum printing process was available until the efforts of William Willis, junior, came to fruition. The elder son of a well- known engraver who had originated the aniline process used for copying engineering drawings (29), Willis worked as an engineer before moving into banking. He left the bank to work with his father on a new photographic silver process known as Alsthetype, but finding that the silver process was not permanent he determined to find a metal that would be stable under all conditions, and eventually selected platinum (30).

Many difficulties had to be overcome, but in 1873 he received his first patent for the invention of “Improvements in Photo-Chemical Printing” (3 I). This involved the application of solutions of simple or compound salts of platinum, iridium or gold to the surface of paper, wood or other materials suitable for printing photographic images on. In this original process three coating operations were carried nut, the first using a solution of chloro- platinate or chloro-platinite of sodium. When this was dry the next coating, preferably the nitrate of silver, was applied and this was


followed by a final coating with a solution of ferric oxalate, or tartrate. Once dry the material was ready for exposure through a photographic negative, then the image was developed in a solution of potassium or ammonium oxalate. The picture was next rinsed in dilute acid, washed, immersed in a solution of hyposulphite of soda and again washed. This platinotype process was long and complicated, but was the subject of constant development and in 1878 and 1880 Willis received further patents for inventions that both simplified and improved on the original process (32, 33).

In 1881 William Willis was awarded the Progress Medal by the Photographic Society for his invention of the platinotype process. The medal was received on his behalf by Herbert Bowyer Berkeley (1851-1891) one of the senior employees of the Platinotype Company, the firm founded by Willis to manufacture platinum papers for the photographic trade. In thanking the Photographic Society, Berkeley, an excellent photographer who made many significant contributions to the subject, stated that

William Willis 184 1- 1923

In addition to his photochemical patents between 1888 and 1905 Willis shared seven patents relating to other inventions with Mr. W. H. Smith, the works manager of his factory at Penge. These included a lamp for producing a particularly bright light for photographic purposes and airtight containers for storing sensitised platinum photographic papers, for these were degraded in a moist atmoqhere. Willis was attracted to scientific work of any description, at one time particularly. the spectrographic analysis of metal and mineral samples collected by friends he had made during visits to the U.S.A. In addition his scientific knowledge was available to his two local hospitals both of which obtained their first X-ray apparatus because of his appreciation of their usefulness

Mr. Willis was engaged in perfecting the platinotype process, and hoped before long to have something new to lay before the Society.

Paper manufactured by the Platinotype Company was marketed in the U.S.A. by Willis and Clements of Philadelphia but other organisations on both sides of the Atlantic also started to produce their own variety of platinum printing papers. However, Willis continued with his researches and two further patents relating to improvements in his process followed in 1887 (34, 35).

Platinum prints were superior in so many respects to those produced by other processes. When correctly developed, and adequately cleared and washed the prints remained in good condition unless the paper support was burnt or physically damaged. The texture of this support could be selected to contribute to the overall appearance of the picture, thus beautiful art papers as well as vellums and fine tissues were employed. Of course, there was no emulsion to mask this texture as the image consisted solely of platinum metal. Additionally the use of platinum enabled a very wide range of tones to be reproduced on the positive print, including the most delicate gradations recorded on the negative, while by varying the components of


The factory of the Platinotype Company a t Penge was regarded as a model one, in the sense that no scientific or technical means were neglected and no expense spared in making the materials as perfect as was humanly possible. Before a roll of photographic paper was released from the factory it was tested by exposing a sample through one of a number o f standard negatives. The sepia print reproduced here, showing the painting entitled “Souvenir de Mortefontaine” by the French artist Corot, is believed to be one such test print. I t was given to Arthur J. Webb when he was employed as William Willis’s private research assistant and remained in the possession of hi5 family until 1980 when i t was presented to Johnson Matthey. The sepia paper, with its beautiful warm, brown tone was discovered by accident and involved the presence of mercury, although attempts were made to keep the process secret (Size of photograph 15% x 12 inches)

the sensitiser and the developer the grey colours characteristic of platinotype prints could be varied from a harsh black through to browns, or even red.

The Platinotype Company bought its platinum from Johnson Matthey in the form of the salt potassium chloro-platinite and Johnson Matthey’s figures for the early part of this century show that sales of this salt reached a peak of 14,965 oz in 1905 (36); it is perhaps significant that it was at about this time that the price of platinum first exceeded that of gold. In addition, the decline in the popularity of the platinotype process was due, in part, to the worthwhile improvements that had been made

in other photographic processes and in the quality of the materials available.

Later Willis responded by introducing a silver-platinum Satista process (37) and a palladium process but neither achieved the success of the platinotype.

The link between Willis and Johnson Matthey was not confined to the supply of platinum salts. Much of Willis’s early funda- mental research was undertaken in a laboratory built in the garden of his residence in Bromley, and here for a time he employed as his private chemist a man named Arthur James Webb. In I 905 Willis decided to move into the country to Brasted Chart, Kent, and not wishing to uproot


William Willis bought his platinum, in the form of the s a l t p o t a s s i u m c h l o r o - plat ini te , f rom Johnson Matthey and the latter’s sales figures for this chemical illustrate the rise and fall in t h e p o p u l a r i t y of t h e platinotype process. The largest amount was sold in 1905, about the time that the pr ice of p la t inum first exceeded that of gold. A gradual decline in sales followed over the next nine y e a r s u n t i l r e s t r i c t i o n s imposed in the U.K. during the war interrupted the supply of platinum for this purpose. Following the dea th of William Willis the Platinotype Company passed to his brother John Willis, who incorporated it as a private limited company in 1021 but in 1932 it was voluntarily wound up


For a time William Willis occupied South Hill House on Mason’s Hill in Bromley, Kent and this building in the garden o f the residence served as his private laboratory and work- shop. The figure standing in the doorway is A. J. Webb. Reproduced from a platinotype print made in 1905

186

his young assistant, Willis introduced him to Johnson Matthey. Webb was an honours graduate of both Oxford and London Universities and had some three years experience with the chemistry of the platinum metals. As a result, Johnson Matthey was pleased to offer him employment and he soon made significant improvements in the platinum refinery at Hatton Garden.

By I 9 I 3 Johnson Matthey sales of potassium chloro-platinite were down to 4,544 02. With the start of the First World War greatly increased demands were made on the chemical manufacturing industry and this led to an unprecedented use of platinum. Unfortunately it also put a temporary stop to the use of the metal for platinotype photography.

Towards Photographic Perfection with the Platinum Metals

When presenting the Progress Medal for the invention of the platinotype process the Pre- sident of the Photographic Society said:

“The excellence of the results obtained by this process has been rendered evident by the specimens shown in our last two exhibitions, and in the very fine enlargements exhibited at the Society’s meeting in April, 1880. These mark a new era in photography.. .the quality of permanence has come to be regarded as one of the chief recommendations of the platinotype process, which in the hands of Mr. Willis has gradually progressed so far towards perfection that pure platinum-black . . . constitutes the sole ingredient left in the texture of the paper”. (38)

Despite the application of the newest technology, it must be accepted that the mechanical processes used to print this journal are incapable of reproducing the beautiful appearance of the best original platinotype photographic prints. For this reason, and with some regret, the platinotype prints illustrated here have been selected for their historic interest, rather than their aesthetic appeal. However, readers are most earnestly advised to visit one of the museums or libraries holding early platinotypes and there see for themselves the beautiful works of art that were being

This view of the interior of Willis’ private laboratory, with darkroom beyond. shows his assistant A. J. Webb preparing for the move to Brasted Chart. After Willis moved the house was no longer used as a private residence, and the site has since been redeveloped. The platinotypt- prints from which this illustration and the preceding one were prepared remain in the possession of the Webb Family and, as far as is known, they have not been published previously


produced by this process around the turn of the A c k n o w l e d g e m e n t s century by the leading photographers of the The author has gained much background informa-

tion from the standard texts on the histories of day; they are to be disappointed. photography and of the platinum metals, principally Perhaps then they may wish to seek out some of the Epstean translation of J. M. Eder’s “History of the contemporary images that are now being Photography”, ‘‘The History of Photography” by H.

Gernsheim and A. Gersheim, and “A History of produced in the platinum metals by a Platinum and its Allied Metals” by D. McDonald and number of DhotoeraDhic artists on both sides of L. B. Hunt, Johnson Matthey, London, 1982.

is currently enjoying a modest revival (39). House are reproduced by courtesy of Mr. R. S. Webb.

References I J . Werge, “The Evolution of Photography”, 23 (G. Wharton Simpson), Phorogr. News, April 15,

24 R. Desmond, “India Office Library & Records,

2 5 Phorogr. SOC. Bombay J., Feb.-June 1856, (13-

4 J. Pizzighelli und A. Hubl, “Die Platinotypie”, 26 Phorogr. SOC. Bombay J., Jan. 1855, ( I ) , ii-iii, Wien und Leipzig, 1882 “Introductory Address”

5 Capt. Pizzighelli and Baron A. Hiibl, 27 The National Army Museum, London, “The “Platinotype”, Harrison and Sons, London, I 886 Hodson Index”

6 J. Pizzighelli and A. Hubl, “La Platinotypie”, 28 Private communication from Mrs. V. M. Pasteur Gauthier-Villars, Paris, I 883 to Mr. D. McDonald, October I oth, 1947

7 W. Lewis, “Commercium Philosophico- 29 William Willis, (snr.), Brirish Parenr, 2800; 1864 Technicurn”, London, IT63; see F. w. Gibbs, Platinum Metals Rev., I 963, 7, (2), 66-69

31-39 J, M. Eder, ‘tHistory of photography>?, trans, by E. Epstean, Columbia University Press, New York, 1945, P. 95

Piper & Carter, London, I 890, p. 109; Reprinted Edition by Arno Press Inc., New York, 1973

2 W. de W. Abney, Photogr. J., Jan.-May 1883, New Series VII, (4-8), 67

I 864, VIII, (293), 182

Report 1974”, 1 5

3 J. Pizzighelli and A. Hubl, op. cir., (Ref. 2), 69 171, 54

30 (E. A. Salt), Photogr. J., June 1923, LXIII, 300 3 I William Willis, junior, British Parenr, 201 I ; I 873

33 William Willis, junior, British Parenr, I I I 7; 1880 34 William Willis, British Parenr, I 68 I ; I 887 35 William Willis, British Parent, 16,003; I 887

10 Op. cir., (Ref. 9), p. 147 36 Unpublished records, Johnson Matthey & Co I I Op. cir., (Ref. 9), pp. 172, 177 1 2 J. F. W. Herschel, Phil. Mug., 1832, I, 58-60 37 William Willis, British Parent, 20,022; 1 9 1 3 1 3 L. Schaaf, Hisr. Photogr., 1980, 4, (3), 181 38 (J. Glaisher), Photogr. J., 24 June 1881,V, (9), 149 14 R. Hunt, “Researches on Light”, Longman, 39 J. Hafey and T. Shillea, “The Platinum Print”,

L’ B‘ Hunt, Rev’> I9”> ’49 ( I ) , 32 William Willis, jnr., Brjrjsh Parenr, 2800; 1878

Limited

Brown, Green, and Longmans, London, I 844; Reprint Edition by,Arno Press Inc., New York,

Graphic Arts Research Center, New York, I 979

I 973, P. iv

3, (401, 14

( 1 3 w 3 (P. 2)

1 5 P. Ellis, ColdBull., 1975, & ( I ) , 7-12 1 6 (For example)J. Phorogr. SOC., March 21, 1856,

17 The Daily Scotsman, Thursday, Sept. 22, 1859,5,

I 8 Phorogr. 3. (Liverpool), Jan. I 5 , I 859, VI, 22

19 H. Gernsheim and A. Gernsheim, “The History of Photography”, Thames and Hudson, London,

20 C. J. Burnett, Phorogr. 3. (Liwerpool), July I ,

21 C. J. Burnett, Phorogr. 3. (Liverpool), Aug. I ,

22 W. de W. Abney and L. Clark, “Platinotype; its Preparation and Manipulation”, Sampson Low, Marston & Co., London, I 895, p. 26-27

I969

1859, VI, 162, and Aug. I , 185-186

1859, VI, 123

The Johnson Matthey Collection As a contribution to the revival of platinum

printing Johnson Matthey Incorporated of Malvern, Pennsylvania are working with Tom Shillea of the Rochester Institute of Technology to improve the platinum group metal salts used for this photographic process. In addition they have assembled for exhibition a collection of some of the most outstanding examples of platinotypes produced throughout the years by noted American artists. Organisations interested in displaying this collection should communicate with Mr. J. H. Povey, Manager of Public Affairs at Johnson Matthey Inc., Malvern, Pennsylvania I 9355-2 I 96, U.S.A.


produced by this process around the turn of the Acknowledgements century by the leading photographers of the The author has gained much background informa-

tion from the standard texts on the histories of day; they are to be disappointed. photography and of the platinum metals, principally Perhaps then they may wish to seek out some of the Epstean translation of J. M. Eder’s “History of the contemporary images that are now being Photography”, ‘‘The History of Photography” by H.

Gernsheim and A. Gersheim, and “A History of produced in the platinum meta1s by a Platinum and its Allied Metals” by D. McDonald and number of photographic artists on both sides of L. B. Hunt, Johnson Matthey, London, 1982.

and to the librarians, who contributed information. of the platinum metals for photographic Prints The platinotypes of the laboratory at South Hill is currently enjoying a modest revival (39). House are reproduced by courtesy of Mr. R. S. Webb.

the Atlantic. In the U.S.A. in particular, the use Thanks are also due to the historians of Photography

J . B. Boussingault and Platinum Boussingault D. Reidel Publishing Company, Dordrecht and London, 1984, 280 pages, L35.50

BY F. W. J. McCOSH,

Most of the distinguished chemists of nineteenth century France have formed the subjects of intensive study and the preparation of biographies but Jean Baptiste Boussingault (I 802-1 887) has hitherto been neglected in this respect. The major part of his long career (his many papers published in Comptes Rendus and Annales de Chimie et Physique extend over more than sixty years) was devoted to agricultural chemistry, but for readers of this journal interest attaches more to his work on platinum in his youth.

When only eighteen and a student- demonstrator at the newly formed &ole des Mines at Saint-Etienne, Boussingault attempted to produce an alloy of platinum and carbon but succeeded only in making a low melting platinum silicide, setting fire to his laboratory in the process. Undeterred, he visited Paris and called upon Gay-Lussac to present him with a copy of the resulting paper which was duly published in 1821 in the Annales. Still only twenty years old, he was recruited by Alexander von Humboldt who was organising a group of scientists, at the behest of Sim6n Bolivar, to investigate the mineral and agricultural potentialities of newly liberated Colombia. First appointed as a professor at the Escuela Nacional de Mineros in BogotP, Boussingault was given assignments that took him to various parts of the country as mine inspector, prospector and assayer, and it was during one of these missions that he climbed to a nine thousand feet high plateau near Medellin where gold mining was being carried on and discovered rounded grains of native platinum in the ore that was being mined, so establishing the source of the alluvial platinum that had been discovered and extracted for some forty years in the Choc6 region. This he reported in a letter to his patron Humboldt who promptly had it published in the Annales de Chimie et Physique in I 826.

This discovery of the source of the alluvial platinum coincided with the zenith of Bolivar’s career and prompted the Colombian Congress to propose the erection of a large equestrian statue of the Great Liberator in the main square of BogotP, Boussingault being instructed to superintend its casting and erection. He was well aware, however, that all the mines of Colombia could not possibly yield the necessary quantity of platinum and that in any case it was not then capable of being melted and cast. By diplomatic delaying tactics he was able to wait until the whole idea had been forgotten and in the event he received only two kilograms of platinum which he used to make several pieces of apparatus for himself. His brother-in-law Sylvestre Vaudet, a building contractor in Paris, also suggested that Boussingault should export platinum to Europe, but nothing came of this idea.

Boussingault returned to France in 1832, accepting a number of professional appointments, first at Lyon and later at the Sorbonne and the Conservatoire des Artes et Mitiers in Paris, now pursuing his classic studies in soil science and plant nutrition, later being awarded the Copley Medal by the Royal Society “for his long, continued and important researches and discoveries in agricultural chemistry”. Later in life he moved into the field of steel metallurgy and was among the first to study the alloying effects of chromium, although he never lost his interest in platinum.

Dr. McCosh, who contributed an article to this journal on Boussingault’s activities some seven years ago (Platinum Metals Rev., 1977,z1, (3), 97-roo), has delved extensively into the relevant archives and has presented a most interesting and detailed account of the life and work of his subject against the background of the slow development of chemistry, the chemical industry and metallurgy in nineteenth century France. L. B. H.


ABSTRACTS of current literature on the platinum metals and their alloys

PROPERTIES Anisotropy and Magnetostriction of Pt-Fe Alloys M. PARDAVI-HORVATH, L. I. VINOKUROVA and v. YU. I V A N O V , ~ . Magn. &Magn. Mater., 1984, 41, (1-31, 349-351 Temperature and magnetic field dependencies of magnetisation, magnetostriction and thermal expansion were measured for ordered Pt-Fe alloys in the range 25-32at.O/oFe of the transition from antiferromagnetism to ferromagnetism, through formation of clusters embedded in the antiferromag- netic matrix. Anisotropy of the critical fields were determined and the reorientation of the vector of antiferromagnetism was followed. Tetragonal distor- tion of the lattice accompanies the change of the effective anisotropy field.

Solubility of Protium, Deuterium, and Tritium in the a Phase of Palladium R . L A s S E R , P ~ ~ ~ . Rev. B, 1984,29, (8), 4765-4768 The first solubility determinations of T in bulk Pd are presented for the pressure range 0.0 I 6 < p < I .33 bars, temperature range 60-4oo°C and concentration range, x, in PdT, of 0.0015-0.02. Also the first comparative study of the pressure-composition- temperature relationship of all H isotopes in Pd at low concentrations is described.

Some Transport Properties of Palladium Films M. A. ANGADI and s. M. SHIVAPRASAD, 3. Mater. Sci.,

The effect of deposition rate and substrate temperature on the electrical resistivity, TCR and thermoelectric power of Pd films of 2-25nm thickness was found to be marked. Higher rates of deposition and substrate temperatures result in larger grains and hence changes in transport properties.

Effect of Heat-Treatment on the Hydrogen Sensitivity of ZnO Thin Films Loaded with Palladium Salts w. B. LI, H. YONEYAMA and H. TAMURA, Marer. Chem. Phys., 1984, 10, (I), 69-81 Porous ZnO thin films were impregnated with Pd salts from their aqueous solutions, heat treated and assessed for H z sensitivity. During impregnation of PdC12, a ZnClz.4Zn(OH)z phase is formed, in a surface region which retards the appearance of the H Z sensitivities. By heating the sample at 140-200°C this phase is decomposed, but the impregnated PdCIz is not decomposed, and a remarkable HZ sensitivity appears, even at room temperature. Similar situa- tions hold in the loading of other I'd salts.

19849 199 (71, 2396-2400

Solidification Structures in Single Crystal Copper-Rhodium Alloys with [ Rh] < 15 at.% c. TSELENTIS, M. JARDINIER-OFFERGELD and F. BOUILLON,Ann. Chim. (Paris), 1984, 9, (2), 141-144 Cu-Rh single crystal alloys containing 1.5-1 5 at.% Rh were grown unidirectionally from the melt. A dendritic-cellular or sometimes dendritic structure as predicted by Titler's criteria occurred, and could be identified by microscopy after chemical etching. It is shown that this microsegregation could be reduced by high temperature annealing. Times required to homogenise the solidification structures are shorter than the values predicted by the Fleming model.

Electrical Resistance in Sirperronclucting .Amorphous Alloy Zr Jr:!,, N. TOYOFA, A. INOUE, K. MATSUZAKI, T. FUKASE and 1'. MASUMOTO, J. Phys. SOC. Jpn., 1984, 53, (3), 924-927 The electrical resistance of Zr701r30 (p = 300p l2 cm, Tc= 3.67K) was examined. The resistance increases by 3.770 on cooling from 3ooK down to roK where it has a hump, and then decreases rapidly approaching Tc. Above 27K any magnetoresistance is not detected, but between I .7K<T< 27K a positive magnetoresistance is seen and becomes saturated above H,= 12-13T.

Surface Coordination Chemistry o f Ruthenium. A Survey of Ruthenium (001 ) Surface Chemistry K. L. SHANAHAN and E. L. MUEITERTIES, 3 . Phys. Chem., 1984,88, ( I 0), I 996-2003 The chemisorption behaviour of a range of organic and inorganic molecules on the basal plane of Ru, RU(OOI) was studied. The close-packed Ru surface proved to be very reactive and most of the studied molecules were irreversibly chemisorbed at 25°C. Only CO, PF3, CF3CN, HCN and (CN)2 showed some degree of molecular thermal desorption after adsorption at 25°C.

CHEMICAL COMPOUNDS Synthesis of the First Pt-Au Cluster by an Unexpected H+-Substitution at trans- PtH(CI)L2 P. BRAUNSTEIN, H. LEHNER, D. MAT, A. TIRIPICCHIO and M. ~FIRIPICCHIOCAMELLINI, Angew. Chem., Int. Ed. E n d . , 1984~23, (4), 304-305 In a novel type of exchange reaction at monohydridoplatinum complexes, trans-PtH(C1)Lz (L=phosphane), H+ is replaced by AUZLZ. The compound formed is the first to contain Pt-Au bonds.


A New Type of Decaosmium Cluster Geometry: the Synthesis and X-Ray Structure Analysis of 0 s I"( S ) 2 ( CO) 23 J. P. ATTARD, B. F. G. JOHNSON, J. LEWIS, J. M. MACE, M. McPARTLIN and A. SIRONI, 3. Chem. soc., Chem. Commun., 1984, (9X 595-597 Pyrolysis of os3(co)12 with elemental S gives a range of clusters including O S ~ ( S ) ~ ( C O ) ~ , ossS(Co)i~, Os6(CO)18, O S ~ ( S ) ~ ( C O ) ~ O and Os~~(S)t(C0)23. X-ray analysis shows that the last cluster has a new type of Oslo metal core geometry.

Synthesis of Ruthenium and Osmium Dichalcogenide Single Crystals H. EZZAOU~A, R. HEINDL and J. LORIERS,~ . Muter. Sci.

Single crystals of Ru and 0 s dichalcogenides have been grown for the first time using molten Te and, in the case of RuSz and OsS2, also molten S.

Pentamethylcyclopentadienyl Diruthenium Chemistry N. I. FORROW and s. A. R. KNOX, 3. Chem. SOC., C h m . Commun., 1984, ( I I), 679-681 The chemistry of the di-Ru centre, when stabilised by qCsMe5 ligands, provides examples of new organic transformations such as isomerisation of ethylene to ethylidene and addition of ethylene to vinylidene. It also provides examples of new species such as Ru,(CO)2@-H2) (q-CsMes)~.

h l t . 3 19849 39 (719 625-626

ELECTROCHEMISTRY Application of the S.P.E. Method to Organic Electrochemistry. IV. Electro- chemical Reduction of Aromatic Nitro Compounds on Pt-S.P.E. z. OGUMI, H. YAMASHITA, K. NISHIO, z. TAKEMARA and s. YOSHIZAWA, Denki Kagaku, 1984,52, (3), 180-184 The electrochemical reduction of nitrobenzene and nitrobenzene sulphonic acid was studied on Pt-S.P.E. prepared with Nafion as the S.P.E. material. The reduction of m-nitrobenzene sulphonic acid yielded metanilic acid with very high current efficiency. No reaction selectivity was observed between the two products on Pt-S.P.E., although conditions were favourable to p-aminophenol production.

Reactions of Collodial Platinum in Aqueous Solutions Containing Methyl Viologen, Its Cation Radical, and Hydrogen, Studied by Pulse Radiolysis M. BRANDEIS, G. s. NAHOR and J. RABANI, 3. Phys. Chem., 1984,88, (8), 1615-1623 The reactions of methyl viologen ions, MV2+ and MV' and H2 in the presence of colloidal Pt were investigated by pulse radiolysis. In pH range 1.5-4 all the reducing species were converted into H2. At pH 10, practically all the reducing species produce MV+, while from pH 6-8 the predominant species were Pt particles loaded with H2 as hydride ions.

Hydrous Oxide Formation on Platinum - A Useful Route to Controlled Platinization L. D. BURKE and M. B. c. ROCHE, 3. Electroanal. Chem. Interfacial Elecrrochem., 1984, 164, (z), 3 I 5-334 The formation of thick hydrous oxide films on Pt under triangular potential cycling conditions was studied as a function of sweep rate, sweep limits and pH. The results showed that increasing the cycling rate (from s-~ooV/s) decreased the optimum upper limit (from 2.8-2.2V in acid) for thick film growth. Hydrous oxide growth was observed in both acid and base but not at intermediate pH values of 4.c-9.0. A brief study of the methanol electrooxidation reaction at initially smooth Pt activated by potential cycling and followed by cathodic reduction of the hydrous film, showed that excellent control of the surface roughness and, hence, the level of electrocatalytic activity of the electrode surface was possible.

Specific Features of the Adsorption of Organic Compounds on Platinum at High Positive Potentials. Methanol Solutions L. n. MIRKIND, v. E. KAZARINOV, G. L. AL'BERTINSKII and v. N. ANDREEV, Akad. Nauk SSSR, Efektrokhim.,

Studies were made of the mechanism of adsorption of organic compounds on Pt anodes in aqueous and methanol solutions. The effect of the potentials, time of adsorption, volumetric concentration of adsorbate and potential of electrosorption on the amount of firmly adsorbed particles and the nature of the solvent was studied. Detailed explanations are provided.

Potentials of Zero Charge and the Electric Double Layer Structure of Platinum and Palladium in Dimethylsulphoxide

Akad. Nauk SSSR, Elektrokhim., 1984, 20, (7), 945-950 Curves of the differential capacity were measured on renewable Pt and Pd electrodes in perchlorate solutions and alkali metal halogenides in dimethylsulphoxide (DMSO). The potentials of zero charge were found to be -0. I 5 and OV for Pt and Pd, respectively. A considerable surface activity of DMSO on Pt and Pd was established together with the growth of specific adsorbed anions in the order Clod-< CI-< Br-< I- and weak surface activity of cations which increased in the order Li+< Na+< K+.

Effect of Platinum Elements Additions on the Active Dissolution of Plastic Chromium in Sulfuric Acid N. D. TOMASHOV, G. P. CHERNOVA and E. N. USTINSKY, Corrosion (Houston), 1984, 40, (3), 134-137, 138 Alloys based on plastic Cr with 0.1-0.4wt.% Ru, Pt, Ir or Pd were investigated in 40% H2.504 in the active state under cathodic polarisation (-0.175v). All the studied additions of delaying elements are responsible for the reduced anodic dissolution of Cr. Two mechanisms decelerated the dissolution.

1984920, (71,883487

E. YU. ALEKSSEVA, V. A. SAFONOV and 0. A. PETRII,


Hydrogen Chemical Potentials, Surface Heterogeneities and Solution Diffusive Processes in Hydrogen Electrode Reactions

and M. c. WITHERSPOON, Int. 3. Hydrogen Energy, 1984,9, (41, 303-307 Surface and substrate H potential measurements were used to find rates of permeation of dissolved H2 molecules to and from Pd and Pd alloy electrode surfaces through the Brunner-Nernst layer. These co- joint measurements made it possible to compare the upper limiting H chemical potentials at catalytically active surfaces under H bubble evolution during electrolysis in acid, alkaline and neutral salt solutions. (57 Refs.)

Hydrolysis of the Palladium( 11) Ion in a Sodium Chloride Medium N. B. MILIC and z. D. BUGARCIC, Transition Met. Chem., 1984,9, (9, 173-176 The hydrolysis of the Pd(I1) ion in a NaCl medium was studied at 25OC by the e.m.f. method. The extent of the Pd hydrolysis depends upon the concentration of both Pd and the NaCl medium. Thus the extent of hydrolysis increases with increasing Pd concentration at a definite pH, but decreases with increasing NaCl concentration. The stability constants of the complexes obtained, PdOH+ and Pd4(0H$+ also differ slightly, depending upon the NaCl concentration.

Dioxygen Evolution from Inorganic Systems. Water Oxidation Mediated by RuO:! and TiO:!-RuOZ Colloids

PELIZZE~TI, Inorg. Chim. Acta Articles and Letters, 19843 91 (b9), (415301-305 The kinetics of reduction of aqueous solutions of Ce'" and Ru(bpy)j+ in the presence of catalytic amounts of RuOz colloids stabilised with polybrene and colloidal Ti02 particles loaded with Ru02 have been investigated by stopped-flow spectro- photometric techniques. The effect of pH, catalyst preparation and loading concentration have been considered. The TiOdRuO 2 colloidal particles (45nm radii) are extremely active catalysts.

Studies of the Stability of RuS2 Single Crystals and the Photo-Oxidation of Halides H. EZZOUIA, R. HEINDL, R. PARSONS and H. TRIBUTSCH, 3. Electroanal. Chem. Interfacial Electrochem., I 984, 165,(1/2), 155-166 Anodic photocorrosion of n-RuS2 is very slow under moderate conditions but can be accelerated under extreme conditions of high potentials and rapid 0 2 evolution. The stability is mainly thermodynamic, but may be kinetic to some extent. RuS2 shows an onset of photocurrent which is shifted strongly to lower potentials in the series C1-, Br-, I-. This is related to improved kinetics of the oxidation reaction due to adsorption of the intermediate species.

F. A. LEWIS, R. C. JOHNSTON, S. G. McKEE, A. OBERMANN

C. MINERO, E. CORENZI, E. PRAMAURO and E.

PHOTOCONVERSION Visible Light Induced Hydrogen Production from in Situ Generated Colloidal Rhodium-Coated Cadmium Sulfide in Surfactant Vesicles Y.-M. TRICOT and J. H. FENDLER, 3. Am. Chem. SOC.,

The first use of vesiclestabilised, in situ formed, Rh catalyst-coated colloidal semiconductor CdS in artificial photosynthesis is reported. Band-gap excitation by visible light (A > 35onm) of Rh-coated CdS in dihexadecylphosphate surfactant vesicles produced Ht in the presence of thiophenol, and the H1 production was sustained for approximately 48h. After 48h, more than 90% of PhSH was consumed. These systems may provide means for viable solar energy conversion.

Photochemistry of the Tris( 2,2'-bip)i- ridine)Rulhenium( I I ) - Peroxydisulfate System in Aqueous and Mixed Acetonitrile- Water Solutions. Evidence for a Long-Lived Photoexcited Ion Pair H. s. WHITE, w. G. BECKER and A. I. BARD, 3. Phys. Chem., I 984,88, (9), I 840-1 846 The photooxidation of Ru(bpy):+ by peroxydisulphate, was investigated by steady-state luminescence quenching and emission lifetime techniques in aqueous and mixed CHICN-H~O solutions. The results are consistent with the formation of a ground-state ion pair [Ru(bpy):+.S20;-]. The lifetime of the photoexcited ion pair-ion pair association constant and oxidative rate constant are reported for aqueous and CH ~CN-HIO solutions. The lifetime of the photoexcited ion pair [Ru(bpy),:+.S20k]* is unusually long, ranging from 0-1 I ,us in H20 to 0-53 ps in 50% CH3CN.

Photosubstitution Reactions of Ru( bpy):! XY"' Complexes

(I0),'440-'445

1984,106, (8), 2475-2476

D. V. PINNICK and B. DURHAM, Inorg. Chem. 1984, 2 3 ,

The quantum yields for the photosubstitution of a series of Ru(bpy)2XYn' complexes have been measured. The ligands X and Y span the range of the spectrochemical series from C1- to CO. The correla- tion between the energy of the lowest energy charge- transfer transition and quantum yield is discussed.

Improvement of the Photoelectrochemical Change of H2S over CdS Suspensions Using RuS2 as a Catalyst D. H. M. W. THEWISSEN, E. A. VAN DER ZOUWEN-ASSINK, K. TIMMER, A. H. A. TINNEMANS and A. MACKOR, 3. Chem. SOC., Chem. Commun., 1984, (14), 941-942 Illumination of a suspension of CdS particles loaded with 0.5wt.S RuS2 leads to photocatalytic H2 evolution from alkaline S2-/SO$- solutions with a formal quantum efficiency of 0.12 at 47onm; in comparison with the analogous system, CdS/o.gwt.% RuO2, this represents an improvement by a factor of 7.


LABORATORYAPPARATUS AND TECHNIQUE A Miniature Palladium-Palladium Oxide Enzyme Electrode for Urea Determination N. J. SZUMINSKY, A. K. CHEN and c. c. LIU, Biorechnol. Bioeng., 1984, 26, (6), 642-645 The preparation and evaluation of I'd-I'd0 pH urea electrodes, based on the combination of immobilising urease are described. Full response of the urea electrode was obtained five minutes after transferring the electrode into the test buffer solution, the response characteristics were sensitive to details in the urease-BSA coating of the Pd-PdO pH electrode, and gave reproducible results. The electrode was stable for more than three weeks when EDTA was added to the test and storage buffer solutions.

Magnetic Compton Profile Measurement Using Circularly Polarized Gamma-Rays from Oriented 'ylmIr Nuclei N. SAKAI, 0. TERASHIMA and H. SEKIZAWA, Nucl. Instrum. Methods Phys. Res., 1984,221, (z), 419-426 Circularly polarised I 2gkeV prays from oriented L9LmIr nuclei were used to measure the Compton profile of magnetic electrons in ferromagnetic Fe. Radioactive isotope I9'Os (which decays to 19'Ir) in Fe metal, 'Hd4He dilution refrigeration and a solid state detector with a large active diameter remarkably improved the accuracy of the magnetic Compton profile measurement.

HETEROGENEOUS CATALYSIS Kinetics of Hydrogenation of Melted Benzoic Acid on Palladium Catalyst

KUL'KOVA and M. I . TEMKIN, Akad. Nauk SSSR, Kiner. Karal., 1984, 25, (3), 578-582 The rate of hydrogenation of melted benzoic acid was measured on suspended Pdactivated C catalyst at 130, 150 and 17ooC and H2 pressure of 0.8-gMPa. An agreement was observed between the kinetic equation previously established and the present measurement. The kinetic equation could be applied to hydrogenation processes of benzoic acid.

Hydrogenolysis of Alkanes. Part I. - Hydrogenolysis of Ethane, Propane and n-Butane on 6% Pt/SiOz (EUROPT-I ) G. c . BOND and x. YIDE, J. Chem. SOC., Faraday Trans.

The hydrogenolysis of ethane, propane and n-butane was studied on a 6.3%Pt/SiO2 catalyst (EUROPT-I). Treatment of the catalyst in H2 at 623-1 I73K led to a loss of capacity for Hz chemisorption greater than that attributable to an increase in particle size and to an even greater loss of activity of n-butane hydrogenolysis, which was partly restorable by oxidation. Extensive reorganisation of the metal occurs during a short oxidation at 873K.

V. YU. KONYUKHOV, 1. M. GENKINA, D. I. PERAZICH, N. V.

1.9 19849 80, (41,969-980

Catalysis of the Exchange of Hydrogen and Carbon Isotopes in the Water/ Hydrogen and Bicarbonate/Formate Redox Couples: A Comparison of the Exchange Current Densities on Palladium s. CHAO, c . J. STALDER, D. P. SUMMERS and M. s. WRIGHTON, J. Am. Chem. SOC., 1984, 106, (9), 2723-2725 The exchange of H and C isotopes in the CO,H-/HCO? aqueous redox couple occurs at a rate that is of the same order of magnitude as the H isotope exchange in the H20/H2 aqueous redox system at 298K, using a Pd based heterogeneous catalyst. The catalysts were Pd, Pt on C, PQ.

A Study of the Structure Sensitivity of the Propylene Hydrogenation Reaction over Supported Platinum and Palladium Catalysts E. RORRIS, Ph.D.Thesis, Northwestern Univ., I 983, Diss. Absrr. Int. B, I 984,44, ( I 0), 3 I 46 Propylene hydrogenation was investigated over a series of PdSi02 and PdSiO 2 catalysts; preparations, pretreatments and morphologies were examined. O n Pt/SiOz prepared by impregnation a four-fold enhancement in the turnover frequency occurred as the temperature of treatment in H2 decreased 450°C to -5oOC. Pd/SiO2 had a maxima in the turnover frequency at a H2 treatment temperature of -100°C. Formation of /J-phase of Pd hydride reduced the catalytic activity. Pd catalysts were much more active than Pt catalysts in hydrogenating propylene.

The Oxidation of CO and Hydrocarbons over Noble Metal Catalysts

The oxidation of CO, C3H6, 1-hexene and toluene under excess 0 2 was studied over Pt, Pd and Rh in the form of unsupported wires or supported on p Alz03 or CeOdA1203. The kinetics were affected by the state of metal dispersion, pretreatment temperature, reaction conditions and the presence of Ce02. Two types of surface sites are postulated to explain the results.

Effects of Catalyst Addition to Coal on C 0 2 Adsorption Kinetics of Coal and Char K. OTTO, H. SOREK, L. BARTOSIEWCZ and M. SHELEF, Fuel, I 984,63, (4), 477-48 I

The surface area of Illinois No. 6 coal, impregnated with a series of C gasified catalysts, including Ru, Pd, Pt and Rh was measured by CO2 adsorption before and after pyrolysis. Catalyst addition decreased the surface area of coal accessible to COz in all cases.

Catalytic Combustion R. PRASAD, L. A. KENNEDY and E. RUCKENSTEIN, Caral. Rew. -Sci. Eng., 1984~26, (I), 1-58 A review is given of principles of catalytic combustion, NO, formation and control, catalyst systems including Pt, Ru, Pd, 0 s and Ir catalysts, and the kinetics of fuel oxidation. (I 27 Refs.)

Y.-F. YU YAO,J. Caral., 1984, 87, (I), 152-162


Mechanism of Reactions on Multimetallic Catalysts

A review is given of the mechanism of hydrocarbon reactions carried out on supported and unsupported Ru-Cu, Ru-Au, Ru-Pt, Ru-Fe, Pt-Au, Pt-Ir, Pt-Fe bimetallic systems, by considering the effect of particle size, dispersion, matrix effect, change in H2 coverage, metal-support interaction and suppression of ageing effects. (98 Refs.)

Preparation of Catalysts. Part 2. Depositing a Metal Compound on a Support. Impregnation and Drying c . MARCILLY and J.-P. FRANCK, Rev. Imr. Fr. Per., 1984, 39, (319 337-364 Impregnation and drying, which are two of the operating principles involved in preparing supported metal catalysts are examined. An analysis of the different phenomena accompanying the drying of a simple system composed of one or two pores, then of a more complex system made up of a support with a wide pore distribution, is given. Amonx complexes examined are IrClb, PdCIi- and Pt(NH3):+(56 Refs).

Synthesis Gas Conversion Utilizing Mixed Catalyst Composed of CO Reducing Catalyst and Solid Acid. 11. Direct Synthesis of Aromatic Hydrocarbons from Synthesis Gas

L. GUCZ1,J. Mol. C a d . , 1984, 25, 13-29

K. FUJIMOTO, Y. KUDO and H.-O. TOMINAGA, 3. caral., 1984, 87, (I), '36-143 The synthesis of aromatic hydrocarbons from CO and H2 was studied under pressure using Pd/SiO* and zeolites. Combination of PdSi02 with H-ZSM-5 or H-mordenite gave aromatic hydrocarbons with selectivities > 5 0 % . PdSiO2 with H-Y gave few aromatics. Tetramethyl and pentamethyl benzenes were mostly formed on H-ZSM-5, significantly different from aromatics formed by the methanol reaction on H-ZSM-5.

Optimize Syngas to Naphtha over Ruthenium Catalysts

Process., 1984,63, (6), 95-1 00 The optimisation of a catalyst system for production of crackable feedstock from the partial combustion cracking byproduct syngas was investigated. A series of studies with a number of Co and Ru catalysts using various supports, such as C, AlzO3, H-ZSM-5 zeolite, silica gel and silicalite were performed, Studies were also done with K-promoted R d A 1 ~ 0 3 catalysts and Ru-Ni/AIzO, catalysts. Results were compared, selectivities examined and the effects of surface area were measured. The H s C O ratio was fixed by the conditions of the ethylene production process, and to maximise the C2+ selectivity to obtain the highest possible yield of feedstock crackers to ethylene. An optimised K-promoted RdA1203 catalyst had campaigns of over 1000 hours on stream. The C2+ selectivities averaged -90%.

R. A. STOWE and C. B. MURCHISON, Hydrocarbon

Promoting Effect of V, Mu. \K' and He on the Hate of C - 0 Bond Dissociation of Adsorbed CO in Methanation on Ru/AlnOa

NIIZUMA, T. HATTORI and Y. MURAKAMIJ. Chem. SOC., Chem. Commun., 1984, ( I I), 678-679 Studies of the effect of the addition of V, Mo, W and Re on the rate of C-0 bond dissociation of adsorbed CO in methanation on RdA1203 catalysts was made using pulse surface reaction rate analysis, coupled with an emissionless diffuse reflectance i.r. spectrometer. The addition of these elements was found to increase greatly the rate of dissociation.

High Molecular Weight Hydrocarbons from the Fischer-Tropsch Process with a Pre-oxidized Ruthenium Zeolite Catalyst

SOC., Chem. Commun., 1984, (9), 626-628 The catalytic performance of zeolite based Ru catalyst in the Fischer-Tropsch reaction depends on the sequence of oxidatiodreductions to which they are subjected. With finely divided Ru particles, obtained by reducing [R~(NH+,]~+-exchanged synthetic faujasitic zeolite, CH, is the main product, but when the zeolite is first oxidised in air at 4oo0C, forming Ru02 crystallites which can then be reduced, longer-chain hydrocarbons are produced at low reaction temperatures (I 55OC).

T. MORI, A. MIYAMOTO, N. TAKAHASHI, M. FUKAGAYA, H.

M. AUDIER, J. KLINOWSKI and R. E. BENFIELD,J. Chem.

HOMOGENEOUS CATALYSIS Gas Phase Acetoxylation of 1,3- Butadiene over Palladium Catalysts. Part 1. The Catalytic Activity and Structure of Pd-Sb-KOAc Catalysts n. SHINOHARA,APP~. Caral., 1984,10, (I), 27-42 The gas phase acetoxylation of 1,3-butadiene over Pd catalysts was studied. The Pd-KOAc catalyst gave a very low activity and selectivity to 1,4- diacetoxybutene-2. The main product was I-acetoxy- 1,3-butadiene but, by adding some third components to the catalyst, higher activity and selectivity were obtained; Sb and Bi were the most effective third components. The highest activity was obtained at -0.4 Sb:Pd atomic ratio. It is concluded that the active species on the Pd-Sb-KOAc catalyst is an inter- metallic compound, such as Pd3Sb.

Comparison of Homogeneous and Heterogeneous Palladium Hydrogenation Catalysts

Soc., 1984~61, (41,756-761 1. A. HELDAL and E. N. FRANICEL, 3. Am. oil Chem.

Mechanistic and kinetic studies of Pd-catalysed hydrogenation at atmospheric pressure and 30-100°C were carried out with methyl sorbate, methyl linoleate and conjugated linoleate. Homogeneous Pd catalysts and particularly Pd- acetylacetonate [Pd(a~ac)~] were significantly more selective than Pd/C in the hydrogenation of sorbate to hexenoates, mainly trans-2-hexenoate.


Synthetic Applications of the Palladium- Catalyzed Oxidation of Olefins to Ketones J. T S U J L S y n t ~ s i s , 1984, (51,369-384 A review of the oxidation of olefins to ketones with Pd(I1) salts is presented. Emphasis is placed on the catalytic oxidation of terminal olefins to methyl ketones and the application to organic synthesis. Also regioselective oxidation of some internal olefins by the participation of 0 functions is given. (I 20 Refs.)

0 x 0 Complexes of Ruthenium (VI) and (VII) as Organic Oxidants

LEY and M. SCHRODER,J. Chem. s o c . , Perkin Trans. I, 1984, (4), 681-686 Oxidation of a variety of saturated and unsaturated primary and secondary alcohols by [Ru04I2-, [RuO$, trans-Ba [Ru(OH)203], [RuOzCl$ and [RuO*(bipy)C12] was studied. [Ru04I2- was found to be useful catalytically in conjunction with [S208l2- under basic aqueous conditions. Both [Ru04I2- and [Ru04]- oxidise primary alcohols to carboxylic acids and secondary alcohols to ketones. The new species [PPh4][RuO2C13] and also [Ru02(bipy)C12] cleanly oxidised a wide range of alcohols to aldehydes and ketones without attacking double bonds.

G. GREEN, W. P. GRIFFITH, D. M. HOLLINGSHEAD, S. V.

CORROSION PROTECTION Detection of Hydrogen Generated by Corrosion Reactions Using a Solid Electrolyte Probe s. B. LYON and D. J. FRAY, Muter. Perform., 1984, 23, (4), 23-25 A solid state electrolyte probe for H Z detection either inside solid steel pipes or in the environment has been developed. The probe has different designs depending on the application but all use Pd. The probes are used to monitor corrosion in steel.

ELECTRICAL AND ELECTRONIC ENGINEERING Thermoelectric Effects in Cold Work in Pt/lO%Rh and Pt/13%Rh Versus Pt Thermocouples

(2), 61-66 The effects of cold work introduced in handling Pt- Rh:Pt thermocouples have been investigated. Changes in the Seebeck coefficient of up to -4onVPC and errors in calibration of up to -0.4% were found. Above 2ooOC recovery in the Seebeck coefficient toward its pre-cold-worked value occurred at an increasing rate with temperature, but in the Pt- Rh leg, unlike the Pt leg, the recovery was incomplete. A residual effect, attributed to Pt-Rh, of up to -wV remained in the thermocouple e.m.f. after recovery anneals had been applied. Recom- mendations are made for handling high quality Pt- based thermocouples.

R. E. BENTLEY and T. L. MORGAN,Melro~ogia, 1984, 20,


The Effect of Environment and Materials Properties on the Friction and Wear Behaviour of Precious Metal Electrical Contact Alloy Couples L. E. POPE and R. W. ROHDE, IEEE Trans. Components , Hybrids, Manuf. Technol., 1984, CHMT-7, ( I ) , 56-60 The friction and wear behaviour of Pd base (ASTM B54o) alloy couple and Au base (ASTM B541) were tested in air with 35-45% relative humidity, high purity air and in ultra high purity He. The microstructures and hardness were varied by age hardening, heat treatments and/or cold rolling. The poorest friction performance occurred in the He atmosphere. 0 2 in the environment improved the unlubricated friction performance significantly.

High-Efficiency Ion-Implanted Silicon Solar Cells M. B. SPITZER, s. P. TOBIN and c. J. KEAVNEY, IEEE Trans. Electron Devices, 1984, ED-31, (5), 546-550 The development of solar cells with AM1 conversion efficiency of 18% is reported. The cell comprises an n+-p-p+ structure, fabricated from float zone Si of resistivity 0.3S)cm. The front contact pattern made for Ti-Pd-Ag yielded a shadow loss of 3-4%. The back contact was formed by full-area Ti-Pd-Ag metallisation. The growth of Si02 passivation for reduction of the surface recombination velocity was shown to be important for high cell performance.

Properties of Galvanic Pd-Ni-Coatings at Plug Contact H. GROSSMAN, M. HUCK and G. SCHAUDT, Meta l1 (Berlin), 1984~38, (7), 631-639 The properties of PdNiX (X= 20,35) electrodeposits (with and without AuCo flash) are discussed in comparison to AuCo and Pd+Au-Co(fl). SEM and optical investigations, and measurements of microhardness, frictional forces, contact resistance and internal stress of the electrodeposits were used to describe the friction wear characteristics. The electrodeposits were corroded in H2S, SO2 and NO2 at 400 ppb each for 6 days, and after exposure at 398K and 473K for 96 hours. T h e PdNi20 + AuCo(fl) layers on connectors were found to be at least equivalent to high carat AuCo and Pd + AuCo(fl). The Pd and Ni were in solid solution.

Measurement of the Tunnelling and Hopping Parameters in RuOz Thick Films

Technol., 1984, XI, (2), 123-136 Thick fllm resistors containing a mixture of conductive RuO2 and PbjB2SiOlo have been produced on [(A1203)0.~6(Mg0)0.~] substrates. The TCR of the films was measured for different particle size and concentration of the conductor particles. The TCR was a function of temperature in all the films. From the measured values of negative TCR the tunnelling parameter (Y and hopping parameter B were determined. The results suggest that hopping is important for the low concentration films.

N. Cl HALDER and R. J. SNYDER, E lecrrocompnent s c i .

195

N E W PATENTS METALS AND ALLOYS Amorphous Alloys

Multilayer amorphous alloys are made by rapidly cooling two layers of metal between high-speed rollers. Examples of the pairs of metals include Fe75Si~B I S / P ~ ~ ~ . S S I I ~ . ~ and Fe55NidPdgoSi20.

Titanium Alloys

The fatigue resistance of Ti alloys is increased by ion implantation of a platinum group metal.

TOKYO SHIBAURA DENKl K.K. U.S. Patent 4,428,416

UNITED TECHNOLOGIES CORP. U.S. Patent 4,433,005

CHEMICAL COMPOUNDS Bismuth Pyrochlores E. I. DU PONT DE NEMOURS & co. US. Patent 4,420,422 Pyrochlores of formula Bi2-xM.M',0 7-z are made by firing a mixture of Bi oxycarbonate, M carbonate and MI02 and dissolving out any unreacted material with mineral acid. M is Cu, Cd, Pb, In, Gd and/or Ag, M' is Ru andor Ir, x is 0-0.5 and z is 0-1. The finely divided products are useful as the conductive phase in screen printed thick film resistors.

ELECTROCHEMISTRY Electrochemical Cell ELECTRICITY COUNCIL British Appl. 2,127,856A Electrochemical cells may have an anode of Ti coated with Ru02, Pt or Pt and Ir. One such cell is used in the oxidation of cerous to ceric in aqueous H2S04.

Flexible Electrode GOULD INC. British Appl. 2,129,830A The outer protective and electrically conductive sheath of an elongated dimensionally stable flexible electrode, for use in salt water environments, is preferably formed of RuO2.

Supported-Membrane Diffusion Cell JOHNSON MAlTHEY P.L.C. European Appl. I 06,523 In an apparatus for separating gases by means of a selectively permeable membrane, the membrane is reinforced with a perforated support. The support may be a perforated metal sheet or a sheet of woven metal gauze. The membrane is secured to the support close to each hole in the support. A foil of Ag-Pd is used as the membrane for H2 diffusion.

Chlorine Dioxide Manufacture DIAMOND SHAMROCK CORP. U.S. Patent 4,426,263 C102 is produced by electrolysis of a Na chlorate-H2S04 solution using a cathode coated with catalytic mixed oxides of Ru and Rh, Ru and Pd, Rh and Pd, Ir and Rh, Ir and Pt or, Ru, Rh, Pd.

Electrocatalysts EXXON RESEARCH & ENGINEERING CO.

US. Patent 4,43403 I In various organic electrocatalytic oxidation reactions the catalytic anode coating is a mixed oxide of pyrochlore structure and general formula M ~ ( M ' Z - ~ M ' ' ~ ) O ~ - ~ where x and y are each 0-1, M is Pb, Bi or T1, M' is Pb, Bi, T1 or Sn and M" is Rh, Ir, Ru or Os, such as PbzRu206.5.

Hydrogenation Process KERNFORSCHUNGSANLAGE JULICH Gm.b.H.

German Offen. 3,235,578 Methanol is converted to CH4 and 0 2 by reaction with H2 which is produced simultaneously by electrolysis of, for example a phosphoric acid solution. The anode is preferably made of Pt and the cathode is a foil of Pd through which the H2 diffuses to contact the alcohol, the reverse side of the foil being coated with a Ru catalyst.

ELECTRODEPOSITION AND SURFACE COATINGS High Temperature Coatings AVCO CORP. European Appl. 107,508 Coatings for protecting components of turbine engines consist of MCrAl compositions containing 0.01-3% lanthanide metal(s) and optionally 0.1-10% noble metal, preferably Pt and/or o.1-8% refractory metal. M is a solid solution of Mo, W or Nb in Ni and/or Co.

Palladium-Silver Electroplating Baths LEARONAL INC. European Appl. I I 2,56 I An excess of strong acid added to the plating bath brings the plating potentials of Pd and Ag closer together so that they may be deposited simultaneously. In one example methane sulphonic acid is used with Pd diaminodinitrite and AgNO3.

Platinum Electroplating BELL TELEPHONE LABORATORIES INC.

U S . Parent 4,427,502 Films of improved properties are obtained by electrodeposition of Pt and its alloys from baths containing a 3--2oC polyamine such as 1,3- diaminopropane or diethylenetriamine.

Palladium Alloy Electroplating K.K. SUWA SEIKOSKA AND NISSHIN KASEI K.K.

U. S. Parent 4,42 8,802 An improved Pd-Ni alloy plating solution which can be replenished by the addition of a solid Pd complex contains 5-30gh Pd, added as (Pd(NH3)4C12.H201, and 5-30&/1 Ni, added as Ni acetate or I N ~ ( N H ~ ) z ( S O ~ ) ~ . ~ H 20 I .


Electrodeposited Palladium Alloys LANGBEIN-PFANHAUSER WERKE A.G.

U.S. Patent 4,430,172 The corrosion resistance of a Ni-Pd alloy coating containing 30-9owt.% Pd, formed by electrodeposition from a bath containing ~-3ogh Pd and 5-30&/1 Ni, is improved by including a benzene sulphonyl urea in the bath.

LABORATORYAPPARATUS AND TECHNIQUE Hydrogen Concentration Meter NAI'IONAI. RESEARCH DEVELOPMENT CORP.

British Appl. 2,128,751A A H2 concentration meter includes a conductive component, such as Pd or a Pd alloy, in which Hz is soluble and mobile, a reference electrode which can reversibly accept H Z and which may include anodised Ir, and a solid state electrolyte such as partially hydrated zirconia.

Catalytic Combustible Gas Detectors ENGLISH ELECTRIC VALVE CO. LTD.

British Appl. 2,129,134A A combustible gas detector element includes a heat- able wire filament made of Pt or one of its alloys, embedded in a pellet of an oxidation Pd or Pt catalyst and a carrier therefor.

Pressure Sensor

A pressure sensor, particularly for use in an I.C.E., includes a quartz plate provided with electrode@) by printing with an electrically conductive metal ink, such as an ink containing 15% Au, 2% Pt and 0.066% Rh.

Gas Sensor

M. A. BROOKS AND J. MILER U.S. Patent 4,426,406

WESTINGHOUSE ELECTRIC CORP. US. Patent 4,428,817

A thin film solid-electrolyte sensor for the low- temperature measurement of 0 2 and combustible gases in the presence of each other includes a catalytic electrode chosen from platinum group metals and porous Au or Ag containing perovskite type oxide impregnations and a noncatalytic electrode which may be a poisoned platinum group metal, Au, Ag or a lanthanide metal chromite among others.

JOINING Ductile Brazing Alloys G.T.E. PRODUCTS CORP. European Appl. I 10,4 18 Ductile alloys which contain a reactive metal but still can be rolled down to a foil contain 0.1-4% Ti, Zr and/or V and only one metal selected from Pd, Au, Ag, Fe, Ni, Cu and Al. A typical alloy contains 3% Ti and 97% Pd and is used to bond Mo.

Silver Solder DEGUSSA A.G. German Offen. 3,235,574 An alloy for soldering an oxide-containing Ag contact material to a substrate consists of Ag with 2c-35% Cu and o.1-5% Pd.

HETEROGENEOUS CATALYSIS


Internal Combustion Engines BL CARS LTD. British Appl. 2,129,489A Projections or depressions arranged in the combustion chamber of an I.C.E., of the liquid fuel injection compression ignition type, are coated with a catalytic film of a platinum group metal or a platinum group metal compound.

Olefin Hydroxylation EXXON RESEARCH & ENGINEERING CO.

British Appl. 2,129,800A Olefins are hydroxylated using an 0 s oxide catalyst and NaOH co-catalyst in the molar ratio of Na:Os of

Traction Drive Fluids IDEMITSU KOSAN co. LTD. British Appl. 2,130,600A A base stock for a traction drive fluid is prepared by contacting naphthalene or tetralin or their alkyl derivatives with a Friedelcrafts catalyst followed by hydrogenation using a hydrogenation catalyst containing Pt or Ru.

Reforming Catalysts

0.1:1 t020:1.

EXXON RESEARCH & ENGINEERING CO. European Appl. 107,389

Hydrocarbon reforming catalysts prepared by a specified procedure consist of zeolite L, ion exchanged with Group IA metal(s) and/or Ba and impregnated with o.1-6% Pt, Pd and/or Ir.

Laser Catalyst UNIVERSAL MATTHEY PRODUCTS L'TD.

European Appl. I 07,47 I A catalyst for the oxidation of CO in breathable gases to CO2 consists of a stannic oxide carrier impregnated with 0.5-576 Pt and 0.1-25% Ni or Mn. The catalyst may by used to remove CO produced by a C02 gas laser.

Hydrocarbon Reforming Catalyst EXXON RESEARCH & ENGINEERING CO.

European Appl. I I 1,036 A high activity catalyst able to operate in severe conditions contains 0.1-2% Pt, 0.1-2% Ir, 0.01-0.1% Cu, 0.001-3% Se and 0.1-2.5% halogen (Clz) on A1203 or another oxidic support.

Multimetallic Hydrocarbon Conversion Catalyst UOP INC. European Appl. I I 1,578 A conversion catalyst of exceptional selectivity and resistance to deactivation consists of A 1 2 0 3 or another

oxide carrier supporting 0.01-2% platinum group metals such as Pt, Pd, Ir or Rh, o.os-~% Co, o.o1-5% Sn, o.or-5% P and 0.1-3.5% halogen.

Dehydrogenation Catalysts UOP INC. U.S. Patent 4,420,649 Catalysts for the conversion of alkanes to olefins or ethylbenzene to styrene consist of a porous carrier such as A1203 impregnated with 0.01-2% Pt, 0.01-2% Ru and 0.01-5% Re formed by thermal decomposition of a carbonyl complex.

Reforming Catalyst UOP INC. U.S. Parent 4,426,279 A hydrocarbon reforming catalyst preferably consists of a refractory carrier such as A1203 impregnated with about 0.4% Pt, I % CI and 0.5% I' applied as a compound such as hypophosphorous acid.

Catalyst for I.C. Engine Exhausts PROCArALYSE US. Patent 4,426,319 A catalyst for the purification of automobile exhaust gases consists of a particulate or monolithic carrier, preferably A1203, impregnated with Ce, Fe, Ga and/or Y, Pt, and/or Pd, and l r and/or Rh.

Hydrocarbon Cracking Process CHEVRON RESEARCH CO. U.S. Patent 4,427,536 In a process for cracking S-containing hydrocarbons, a sorbent for S oxides, such as finely divided A1203, is impregnated with a mixture of I'd, and Pt or Ir which catalyses the oxidation of SO2 to SO1 while minimisine the formation of NO,.

Catalyst System BP CHEMICALS LTD. European Appl. 106,656 Homologous carboxylic acids or esters are obtained by reacting an olefin with a formic acid or ester in the presence of Ir chloride promoted with CH31 and p-toluene sulphonic acid.

Rhodium and Ruthenium Complex Catalysts PENNWALT CORP. European Appl. 106~91 I

In a process for the production of amines by photo- activated reaction of olefins with NH3 or a primary or secondary amine, the catalyst may be Ru(PPh3)3C12 or Rh(PPh3)3CI among others.

Hydroformylation Catalyst TEXACO DEVELOPMENT CORP.

European Appl. 107,430 Aldehydes and alcohols are obtained by reacting olefins with CO and Hz in the presence of Ru oxide dispersed in tetrabutylphosphonium bromide.

Alcohol Production from Synthesis Gas TEXACO DEVELOPMENT CORP.

European Appl. 108,848 Methanol and other alcohols may be obtained in a highly selective manner by using a catalyst consisting of a Ru compound, a Re or Mn compound and a quaternary ammonium or phosphonium compound. An inert oxygenated solvent and an optional Group VB donor ligand such as a phosphine are also present.

"

Cont inuous Hydrogen Perox ide

DEGUSSA A,G, European Appl. I I I, I 33 The anthraquinone process is operated with a I'd black suspension in a new in the form of a meander tube.

Rhodium Polymer Complex Catalysts

Hydrocarbon Conversion Catalyst Production STANDARD OIL co. (INDIANA) US. Parent 4,433, I 90 A catalyst for the dehydrogenation andor isomerisation of normal alkanes, especially butane, consists of AMS-IB crystalline borosilicate molecular sieve ion exchanged with I'd or I't and optionally also with La or another metal.

lsomerisation Catalyst AKADEMIE DER WISSENSCHAFTEN DER D.D.R.

East German Patent 206,489 A catalyst for the hydroisomerisation of n. paraffins consists of an A1203 carrier supporting 0.1-2% Pt, 0.1-2% Cr and 0.8-1.4% CI. A typical catalyst contains 0.5% Pt, 0.35% Cr and 1.3% CI and is used for hexane isomerisation.

HOMOGENEOUS CATALYSIS Carbonylation Catalyst SHELL INTERNATIONAL RESEARCH Mij. B.V.

European Appl. 106,379 The formation of carboxylic acids or their anhydrides or esters by carbonylation of olefins in the presence of water, carboxylic acid or alcohol is preferably catalysed by a system consisting of Pd(OAc)2, PPh3 and ptoluene sulphonic acid.

POLYMER SCIENCES CORP. U.S. Parent 4,424,3 12 Catalysts for the asymmetric hydrogenation of unsaturated N-acyl aminoacids are made by reacting a polymer from a pyrrolidine phosphine, a hydro- philic vinyl monomer and a divinyl monomer with a Rh-diene complex such as [Rh(cod)lC12.

Oxidation Catalyst System PHILLIPS PETROLEUM co. US. Parent 4,434,082 A low-corrosion catalyst for use in the oxidation of olefins to ketones preferably consists of Pd chloride, a phosphomolybdovanadic acid and cetyltrimethyl ammonium chloride.

Catalyst System TEXACO INC. U.S. Parenr 4,434,246 A catalyst for the conversion of synthesis gas to ethylene glycol and lower alkanols is a dispersion of a Ru derivative such as Ru02 and a substituted benzene in tetrabutylphosphonium bromide.


1)e-Emulsifier Production TH. GOLDSCHMIDT A.G. German Offen. 3,3 I 2,576 A de-emulsifying agent for crude oiywater emulsions lanthanide is made by reacting a silane with a diene polymer in the presence of a noble metal catalyst such as Pt Infrared Source ethylene pyridine dichloride. HEWLETr-PACKARD CO. European Appl. 106,43 I

A small, inexpensive i.r. source having near black-

thicker layer of Ag andor coating the metal with a protective layer of mixed metal oxides, preferably

FUEL CELLS body emission at 2-2opm consists of a narrow ceramic tube heated with a wound coil of Pt, Rh

Fuel Cell Catalyst and/or Ir wire. INTERNATIONAL BUSINESS MACHINES CORP.

European Appl. 106,197 A catalyst for use in fuel cells consists of a carrier such as C coated with thin, flat, isolated crystallites of Pd, Pt or Ag, formed by electrodeposition.

CORROSION PROTECTION Resistant Alloy Structures TURBINE METAL TECHNOLOGY INC.

European Appl. 108,797 Fe, Co, Ni and their alloys are protected from corrc- sion, erosion and wear by a diffusion coating of Pt, Rh or Pt ternary or quaternary alloy filled with interdispersed refractory particles. A typical coating consists of A1203 particles in an alloy of Rh, Pt, Ni and Al.

Laminated Material for Equipment W.C. HERAEUS G.m.b.H. European Appl. 108,860 Pipes, equipment, etc., liable to come into contact with corrosive atmospheres, especially chemical apparatus, are made from a laminate formed by explosion bonding a steel base to a thin layer of Pt, Pd, Ir, Ti, Nb, Ta, Zr, Ni, Mo, Au, Ag, and/or alloys.

CHEMICAL TECHNOLOGY Colour Photographic Material

The Ag halide emulsion used in a colour photographic material having a polymeric cyan-forming coupler can be chemically sensitised by a Au compound such as a chloroaurate or Au trichloride, or by a salt of Pt, Pd, Ir, Rh or Ru.

FUJI PHOTO FILM CO. LTD. British 2,I 32,370A

ELECTRICAL AND ELECTRONIC ENGINEERING Energy Control Window Films omc.u, COATING LABORATORY INC.

European Appl. 106,223 An energy control window film is claimed which

Low Resistance Elastic Connector

In a connector electro-conductive filaments isolated from each other are allowed to penetrate an electrically insulating elastomer across its thickness to reduce its resistance. The filaments may be stainless steel fibres activated with Pd and plated with Cu, Ni and Au.

Thin Film FET Device

TORAY INDUSTRIES INC. European Appl. 110,383

MATSUSHITA ELECTRIC INDUSTRIAL CO. LTD. European Appl. I I 1,568

A thin film electric field light-emitting device has a thin fluorescent film, a thin dielectric film and electrodes made of Au for applying the voltage. The new dielectric which is superior to Y oxide is a compound of formula AB206 where A is Pd, Sn, Zn, etc., and B is Ta or Nb.

Thick Film Electrodes E. I. DU PONT DE NEMOURS & co. US. Patent 4,426,356 Capacitor electrodes are applied to the green substrate by printing, using an ink consisting of a liquid organic medium and a mixture of 7 ~ 9 5 % Ag, Au, Pt and/or Pd with 0.5-30% specified metal oxide, fluoride, phosphate or glass, preferably Ge02 or PbsGe3011.

Spark Plug Electrode

An improved central electrode for a sparking plug is obtained by sintering a mixture of Ti oxide, carbide or nitride, Pd and/or Pt, and Ag, Rh and/or Ru.

NGK SPARK PLUG CO. LTD. U.S. Patent 4,427,915

MEDICAL USES Organic Platinum Complexes G. E. ADAMS, 1. J. STRATFORD AND 1. AHMED

British Appl. 2,13 1,020A Novel bis(nitrc-I-imidazolyl alkylamine) Pt complexes are useful in increasing the sensitivity of tumour cells to radiation in radiotherapy and in enhancing damage to tumours by chemotherapeutic agents.

shows good performance and can be produced

coating apparatus. The environmental stability and economically and efficiently in a high-rate roll- Dip1atinum Naphthazarinate

RESEARCH CoRP. European Appl. I 09,677 durability of the conventional thin film Ag layer are increased very considerably by alloying the Ag with a small amount of Pd or forming a composite of very thin flash layers of Pd on one or both sides of the

New anticancer agents are complexes of two atoms of Pt wirh halide, amine and other substituents with one molecule of naphthazarine, such as bisdiamine bis-dichloro-p-naphazarinato-diplatinum.


AUTHOR INDEX TO VOLUME Page

Acres, G. J. K. 150, 165 Adrian, H. 134 Aikhlev, B. 135 Aktas, 2. 137 Akyurtlu, 1. 137 Al'bertinskii, G. L. 19 1 Albinati, A. 85 Alekseeva, T. V. 36 Aleksseva, E. YU. 191

Anderson, D. P. 136 Andersson, S. L.-T. 37 Andrew, V. N. 191 Andriollo, A. 140 Anpdi, M. A. 190 Antonov,V.E. 133,135,158 Antonova,T. E. 133,135 Antoshin, G. V. 37 Arai, M. 88 Aramata, A. 134 M i l e s , D. R. 137 Asami, K. 33 Aspnes, D. E. 87 Aston, M. K. 135 Attard, J. P. 191 Audier, M. 194 Awano, K. 35

Alper, H. 39

Baboian, R.

Baird, T. Baltzer, P. Baranowski, B. Bard, A. J. Baronetti, G. T. Bartosiewicz, L. Bartur, M. Basset, 1. M. Beck, M. T. Becker, W. G. Belash, 1. T. 133, Beletskaya, I. P. Beltrame, P. Belyatskii, V. N. Benedek, R. A. Benfield, R. E. Bentley, R. E. Bergbreiter, D. E. Berger, H. Berseneva, F. N. Bichsel, R. Bindner, P. E. Blanton, J. R. Blech, I. A. Blokhina, V. M. Bogomolov, D. B. Bond, G. C. Bouillon, F. Bowman, R. C. Bracey, J. D. Bradley, P. G. Brailovski, S. M. Brandeis, M.

Bachmann, H.4. 90

126 88

139 133

135, 192 137 193 31

138 138 192

135, 158 139 89 37

107 194 195 36 85

133 85

132 36

132 134 34

20, 193 I90 133 138 135 90

191

Brauer, YU. A. Braunstein, P. Brown, D. Brown, F. R. Brunner, H. Buckel, W. Budd, A. E. R. Buffat, B. Bugarcic, 2. D. Burnagin, N. A. Bumagina, I. G.

Page 132 I90 31 37 90

133 115 33

192 139 139

Burch, R. 138 Burke, L. D. 56.87, 191

Caillod, J. 88 Camara, M. J. 34 Cameron, D. S. 19.46 Cantrell, J. S. 133 Carkovic, I. 140 Carrapico, F. 136 Casalone, G. 89 Castro, A. A. 137 Celotti, G. 132 Cerveny, L. 36,88, 138 Chan, A. 137 Chao. S. 34, 193 Chaston, 1. C. 61 Chemleva, T. A. 132 Chen, A. K. 193 Chen, B. 36 Chen, N. 32 Chen, Y. W. 89, 139 Chemova, G. P. 34, 19 1 Chevalier, B. 32.85, 134 Clark, R. J. H. 32 Clarke, J. K. A. 88 Cohen, S. S. 132 Conti, M. 132 Corbiere, 1. A. M. 31 Corenzi, E. 192 Corsini, A. 137 Corti, C. W. I64 Cottington, 1. E. 52, 53, 75,

108, 116, 178 Crawford, J. E. 37 Creaner, A. C. M. 88 Csanyi, L. 1. 87 Culpaz, M. 137 Czeska, B. 33

Dannetun, H. M. Darensbourg, D. J. Dautremont-Smith,H Davidson, R. S. Davies, J. A. Davison, J. B. Dehnicke, K. De Mipel, S. R. Demazeau, G. Dimitrov, D. Domanov, v. P. Donnefly, V. M. Durham, B.

14 I 39

I.C. 32 139 132

38,89 33

137 33

137 135 31

192

Page

Dyrin, V. G. 36

Edwards, M. A. 32 Eisenberg, R. 33 Emmel, P. G. 22 Enyo, M. 87 Etourneau, J. 32, 85, 134 Etter, D. E. 133 Evans, J. I38 EzzaouiaH. 191. 192

Dyer, P. N. 37

Fehrenbach, C. Fellmann, 1. D. Fendler, J. H. Fenske, D. Ferino, 1. Finocchiaro, R. S. Forni, L. Forrow, N. J. Franck, J.-P. Franicel, E. N. Fray, D. J. Fromm, E. Fujiawa, K. Fqjimoto, K. Fukagaya, M. Fukase, T. Fukuoka, A.

Gagne, R. R. Galas, A. M. R. Galbacs, S. M. Gallezot, P. Galoshina, E. V. Gamari-Seale, H. Gancheva, M. Garrou, P. E. Gaset, A. Gaudiello, J. G. Gazarov, R. A. Geerken, B. M. Genicon, J. L. Genkina, 1. M. Gennaro, A. Gentle, T. M. Giessen, B. C. Gignoux, D. Grim, G. C. Godart, C. Goldenberg, E. Gol'dfard, YU. YA. Gomez-Sal, J. C. Gonzalez, R. D. Goodwin, J. E. Goodwin, 1. G. Gorodetskii, A. E Gorodyskii, A. V. Gorokhova, L. T. Griitzel, M. Green, G. Green, M. L. Griessen. R.

35 38

192 33 89 84 89

191 194 194 195 84 33

36. 194 I94 I90 140

140 32 87 88

133 31

137 38 89

135 137 31 32

193 86 88 84 85

137 32 88

137 85

139 139 89 34 88

134 139 195 14 I

28

GMth, W. P. GrifBths, K. Grishina, J. M. Gromov, V. I. Gross, M. E. Grossman, H. Gruenke, L. A. Gryaznov, V. M. Guczi, L. Guha, S. Gupta, L. C. Gursky, J. C. Gurvitch, M. Guseva, M. 1.

Page 195 132 86

133 141 195 132

86, 135 I94 39 32

134 32 34

Hagenmuller, P. 33,85, 134 Halder, N. C. 39,195 Haller, G. L. 37 Hanada, N. 37 Hara, M. 33 Harrap, K. R. 14 Harvey, K. C. 35 Hasegawa, S. 37 Hashimoto, K. 33 Hattori, T. 194 Haushalter, J. P. 34 Heindl, R. 191, 192 Heitbaum, J. 86 Heldal, J. A. 194 Heller, A. 84, 87, 136 Hendriksen, D. E. 140 Henein, G. 91 Herlach, D. M. 84 Hen, R. K. 35 Heywood, A. E. 7 Hidai, M. 140 Higashi, 1. I34 Huai, H. 136, 139 Hiramoto, M. 87 Huao, T. 38 Hitzfeld, M. 133 Hodeau, J. L. 133 Hollingshead, D. M. 195

Hsu, C. S. 140 Huck, M. 195 Hunt, D. J. 139 Hunt, L. B. 52.62, 76, 114,

125, 189 Hursthouse, M. B. 32 Hydes, P. C. 21, 157

Horanyi, G. 33

Ibers, J. A. Iehara, T. Ikuo, A. Ikushima, A. J. Imelik, B. Ino, H. Inoue, A. Inoue, H. Irie, R. Ishikawa, T.

86 87

136 39 88 84

190 89 87 88

3 1 Ishiyama, 1. 136


Page Ivanov, V. YU. 190 Ivlieva. V. 134

Jackman, T. E. 132 Jackson, S. D. 139 Jacobs, P. A. 35 Jardinier-Offergeld, M. I90 Jasinski, R. J. 38 Jenkins, J. W. 98 Jinzaki, Y. 39 Johansen, B. V. 136 Johnson, B. F. G. 19 1 Johnson, M. W. 134 Johnson, R. L. 134 Johnston, R. C. 192 Joo, F. 138 Jung, C. W. 38

Kaedyama, I. 35 Kd, K. 87 Kalck, P. 89 Kdyanasundaram, K. 136 Kanamori, S. 91 Kaneko, M. 88, 135 Kannanov, N. K. 34 Kao, W.-H. 134 Karavanov, A. N. 135 Karlicek, R. F. 31 Kiistner, J. 84 Katayama-Aramata, A. 33 Katsohashvili, YA. R. 137 Kawanishi, Y. Kazanskii, V. B. Kazarinov, V. E. Keavney, C. J. Kemmler-Sack, S. Kendelewicz, T. Kennedy, L. A. ' Keszler, D. A. Kharkova, L. B. Kharlamova, T. A. Kharlamov, v. v. Kharson, M. S. Khidekel, M. L. Khramov, A. V. K i e b m , A. P. G. Kim, M. J. Kmura, H.

Kiss, 1. T. Kita, H. Kitamura, N. Kiwi, J. Klarup, D. G. Klela J. B.

Kipennan, s. L.

35 36

191 195 86 91

193 86 88

134 89

138 139 34 38

132 89

138 139

33,87 35

139 88 35

Kleperis, J. J. Kleshcbevnikov, A. M. Klinowski, J. Knauf, R. Knothe, M. Knox, S. A. R. Kobayashi, M. Kolotyrkin, Y. A. M. Komiyama, H. Komiyama, M.

132 135 194 134 33

191 37

135 89

139

Page Konyukbov, V. YU. 193 Koopman, P. G. 1. 38 Kostyukovskli, M. M. 138 Koyasu, Y. Kozlov, N. S. Kozova, L. Krogmann, K. Kubiak, C. P. Kudo, Y. Kuhnen, N. C. Kulikova, E. A. Kul'kova, N. V. Kurimura, Y. Kunnoo, M. Kuvinova, 1. L. Kuwana, T.

Lamhert, S. E Liisser, R. Lauks, I. Lazareva, L. I. Leconte, M. Lehner, H. Lejay, P. Lejemble, P.

Levinson, M. Levinter, M. E. Levy, F.

Leu, Ic-J.

140 137 137 32

90, 140 194 36

137 193 135 32

135 134

85 190 32 86

138 190

85, 134 89 36 32 36

85.134 Leis, F. A. 13,86, 192 Lewis, J. 191 Ley, s. v. 195 Li, W. B. 190 Lii x. 87 Lin, L. 35 Lindau, I. 91 Lipovich, V. G. 138 Liu, C. C. 193 Loginova, A. N. 36 briers, J. 191 Lubnin, E. N. 135 Lucci, A. 31 Lue, J. T. 39 Lumsden, J. B. 84 Lundstrom, 1. 14 1 Lunsford, J. H. 34 Luss, A. R. 132 Lynch, T. J. 36 Lyon, S. B. 195

McCarthy, M. 87 McGill, I. R. 106 McKee, S. G. 86,192 MacLaughlin, D. E. 32 McNulty, G. S. 138 McPartlin, M. 191 Mace, J. M. 191 Mackor. A. 192 Madalena-Costa, F. 136 Madgavkar, A. M. 36 Magemis, 1. P. 86 Mape, J. T. 86 Maire, Y. 89 Norowski, S. 133 Makovsky, L E. 37

Page Malyshev, V. YU. 133, 158 Mantovani, S. 132

Maran, F. 86 Marcilly, c. 194 Marezio, M. 133 Marko, L 89 Marks, D. N. 140 Maronglu, B. 89 Martens, J. A. 35 Martinez, M. 140 Maruno, T. 84 Masel, R. 1. 31 Massardia, 1. 88 Masumoto, H. 84

Maple, M. B. 85

Masumoto, T. 33,89, 190 Mat, D. 190 Matsumura, M. 34,87 Matsushima, T. 85 Matsuzaki, K. 190 Matveev, v. v. 137 Matzumoto, T. 91 Mebdi, H. 137 Melson, G. A. 37,38 Mlkhalcako, 1.1. 31 Milgram, A. A. 31 Milk, N. B. 192 Minacbev, KH. M. 37,89 Minero, C. 192 Mirkind, L. A. 191 Mitchell, M. D. 138 Miyamoto, A. 194 Mizuno, M. 32 Moissev, V. P. 137 Mokhlcsur Rahman,

A. F. M. 90 Molodkin, A. K. 134 Moravskii, A. P. 34 Moreno Fuken, R. 86 Morgan, T. L. 195 Mori, T. 194 Modmoto, M. 38 Moriya, S. 88

Moyes, R. B. 139 Mostovaya, L. YA. 137

Mozcleski. E J. 140 Muetterties, E L. 88, 190 Murakami, Y. 35,194 Murchison, C. B. Murrer, B. A.

Nahor, G. S. Naito, S. Nakqjjima, H. Nakao, Y. Nakayama, T. Namork, E Nava, F. Nechaeva, N. E. Nefedov, B. K. Nefcdov, 0. M. Nguyen Thi Thanb Ni Zhe-Ming Niizuma, H. Nishio, K.

Konobas, YU. I. 132 MaUya,N. 140 Nishiyha, Y.


194 168

191 37 33 35 88

136 132 88 36 89 36

136 194 19 I 88

Niwa, M. Nobili, C. Noda, H. Nordquist, A. F. Norton, K. A. Norton, P. R. Nod, R.

Ohennann, A. ogumi, 2. Ohnishi. R. ohsbiro, Y. ohsugi, Y. Ohsumi, T. Ohta, T. Ohtani, T. ojjima, 1. okuda, 0. Okuda, Y. Orita, H. O~am~ra, K. Oswald, A. E. Otsuka, R. Otto, K. Ovdes, C. OZRka, F.

Paccard, D. Pais, M. S. S. Pakkanen, T. A. Pal4 M. Palecek, E Pan, J. T. Pan, S. H. Panchishnyi v. 1. Pandey, K. K. Panov, s. Yu.

Page 35

132 136 37

135 132 87

192 191 134 38 38 38 90 85

139 36 39 37

133 140 84

193 39 85

85 136 86 39

137 132 91

137 38 89

Papa, L. E 141 Pardnvi-HoWath, M. 190 Parera, J. M. 137 Park, Y. 0. 31 Parks, R. D. 32 Parsons, R. 192 Paseka, I. 88 Pecrce-Landers, P. J. 38 Pelizzetti, E 192 Penchev, V. 137 Perazich, D. I. 193 Petemson, L-G. 141 Petrignani, J.-F. 39 Petril, 0. A. 191 Petro, W. G. 91 Pidaszek, J. 109 Pierantozzi, R. 37 Pignatel, G. 132 Pinnick, D. V. 192 Plavnik, G. M. 137 Polova, N. M. 36 Polyakova, v. P. 84 Ponyatovsky,E.G. 135,158 Pope, L. E 195 Posh, B. M. 138 Pouchard, M. 33 Pramauro, E. 192 Prase4 R. 193 Pregosin, P. s. 85

Premachandran, V. Prigent, M. Pryde, E. H. Puddephatt, R. J. Puippe, J. C1. Pursiainen, J.

Queirolo, G.

Rabani, J. Raevskaya, M. V. Rand, D. A. J. Rashupkin, V. I. Rassian, V. H. G. Raub, C. 1. Reavill, L. R. P. Reid, F. H. Reisch, J. C. Remeika, J. P. Rena-Descalzi, L. Renner, H. Resasco, D. E. Reuter, W. Rizmayer, E. M. Roche, M. B. C. Rohde, R. W. Rojas, D. Rorris, E Rosch, M. Rowe, M. S. Rozental, A. L. Ruckenstein, E. Riiegger, H. Russell, M. J. H.

Page 39 Shelef, M. 88 Shera,E.B.

140 Shida, J. 32 Shifiett, W. K.

1 I7 Shinohara, H. 86 Shivaprasad, S. M.

Shkitov, A. M. 132 Shlapak, M. S.

Shpiro, E. S. 191 Shubina, T. S. 132 Sbvets, V. A. 135 Simon, N. M. 133 Su0ni.A. 88 Suotkiia, I. G. 63 Smeaton, W. A.

2 Snyder, R. J. 54 Siiderberg, D.

140 SOJ%& S. A. 133 137 126 37

134 33

191 195 138 193 32

7 137 193 85

177 Ruzicka, V. 36.88, 138

Safonov, S. A. 137 Safonov, V. A. I9 1 Safronova, L A. I39 saho, Y. 34 Saia, R. J. 132 saito, Y. 87 Sakai, N. 193 Sampathkumaran,E.V. 133 Sanchez-De1gado.B. A. 140 Sariego, R. 140 Sass, A. S. 36 Sato, S. 34, 135 Savel'eva, G. A. 36 Savitskii, E. M. 84 Scannell, R. A. 56 Scelza, 0. A. 137 Schaller, H.-U. 86 Schaudt, G. 195 Schnoes, K. J. I4 1 Schriider, M. 195 Scurrell, M. S. 31

Sekiuawa, H. 193

Shafuovich, V. YA. 34 Shan Xiao-Quan 136 Shanahan, K. L. 190 Shgnina , M. A. 36 Sharma, S. P. 91 Shebaldova, A. D. I39

Searles, R. A. 12

Sell, J. A. 35

Page 193 134 38 89

194 190 89 90 37

133 36 89

191 137 25

195 I4 1 89

Sokolovskaya, E. M. 1 3 2 Sorek, H. 193 Spencer, A. 90 Spicer, W. E 91 Spitzer, M. B. 195 Sproles, E. S. 91 Srinivasan, S. 133 Ssebuwufu, P. J. M. 86 Stalder, C. J. 34. 193 Stark, D. S. 166 Stock, L. M. 37 Stocker, P. J. 84 Stolt, K. 31 Stowe, R. A. I94 Stradins, J. P. 132 Stuchberv. A. E. 35

_ I

Sturzenegger, B. Subomura, H. T. Sulpice, A. Summers, D. P. Sundman, B. Sunna, K. Suzuki, K. Suzuki, R. 0. Swartzendruber,L. Swifi, H. E. Szuminsky, N. J.

'Takagi, Y. Takahashi, N. Takahishi, M. Takemara, Z. Takeris, S. J. Takeuchi, R. Tamura, H. Tamura, K. Tanaka, A. Tanaka, K. Tanaka, T. Tatsumi, T. Tazuke, S. Tedoradze, G. A. Temkin, M. 1. Temkin, 0. N. Terashima, 0. Teratani, S. Thanh, N. T. Theolier, A.


117 87 32

34, 193 32.85

88 87

133 J. 32,85

36 193

136 37, 194

I36 191 132 38

190 37 84

38, 136 38 36 35

134 I93 90

193 136 138 138

Page Thewissen, D. H. M. W. 192 Thomii, A. I34 Thornson, S. J. 36 Tien, C. 32 Timmer, K. 192 Timofeev, N. 1. 133 Tinnemans, A. H. A. 192 Tiripicchio, A. 190 TiriDicchio-Camellini,

M. Titova, L. 1. Tkachenko, 0. P. Tobin, S. P. Tokumitsu, K. Tomashov, N. D. Tominaga, H.-0. Torkos, K. Torrazza, S. Toshima, N. Tournier, R. Toyota, N. Tri, T.-M. Tributsch, H. Tricot, Y. M. Triggs, P. Trofimov, M. I. Tsai, C. L. Tse, K.-T. Tselentis, C. Tseung, A. C. Tsubomura, H. Tsuchida, E. Tsuji, H. Tsuji, J. Tsuji, Y.

Uchida, H. Uchida, Y. Umezawa, Y. Underhill, A. E. Uosaki, K. Usha, S. Ustinsky, E. N. Utimoto, K.

Valagene, E. G. Valderrama, M. Valencia. N.

I90 137 37

195 84

34, 191 36, 194

33 89

136 32

190 88

192 192 134 89 84 37

190 139 34

135 84

195 38.90

84 I40 34 32 87

133 191 89

37 I 4n

Wagner, F. Wagner, F. E. Wang, C. Wang, H.-T. Warren, L. F. Wassermann, E. F. Watanabe, K. Watanabe, Y. Waterstrat, R. M.

Page 33

134 35

89, 139 136 84 84

38,90 85

Webb, G. 36 Weitkamp, J. 35 Welewski, M. 33 Wells, P. B. 139 White, H. S. 192 Whyman, R. 90, 139 Wilde, B. E. 84 Wdkins, A. J. J. I74 Williams, M. D. 91 Willsau, J. 86 Witherspoon, M. C. 192 Woodruff,W.H. 135 Woods, R. 135 Woolf, L. D. 85 Wrighton, M. S. 34, 193 Wu, J. 90, 140 WU, J.-C. 36 Wu, R. 35

Xu, H. 32

Yagodovskii, V. D. Yakovleva, A. A. Yamada, A. Yamada, Y. Yamaguti, K. Yamamoto, A. Yamamoto, T. Yamamura, T. Yamashita, H. Yamazaki, T. Yanchuk, A. F.

Yazdani, A. Yide, X.

Yang, c.

31.86 135

88, 135 136 135 85 85 34

19 I 87

137 32 31

193 . .- Yokoyama, A. 89

Van Bekkum, H. Yoneyama, H. 190 Van Den Broeck, H. 46 Yoshizawa* s. 191 Van Der Zouwen-Assink, yu yao, v.-F. 193

192 Yuen, M. F. 32 E. A. Van Duyne, R. P. Vannicc, M. A. Vartanov, I. A. Vasekii, V. V. Venturello, G. Viadimirov, B. G. Vianello, E. VGayaraghavan, R. Vinokurova, L. 1. Vlasse, M. Vogel, R. F. Vojtiskova, M. Volkenshtein, N. V. Voronova, L I. Vovchenko, G. D.

202

34 138 138 132 31 34 86

133 190 85 36

137 133 84 86

Zaitsev, B. E. Zalavuidiiov, R. K Zelyaeva, E. A. Zhang, Li Zhiltzova, 0. A. Zhizhenko, G. A. Zhmurko, G. P. Zhu, J. Ziemann, Z. Zingaro, R. A. Zsednai, A. Zubarev, YU. A. Zvara, 1.

I34 .H. 34

86 136 34

137 132 32

133 140 87

31.86 135

SUBJECT INDEX

a = abstract Page Absorption, H, in Pd, Pd alloys 13,31 Acetoxylation, butadiene over Pd-Sb-KOAc, a I94 Acetylene, hydrogenation on Pt foil, a 86 Adsorption, CO, H,O, on Pd/rare earth oxides, a 138

CO,NO on Pt (410), a 31 CO, on coal. a 193

33 H, on Pd-Rh catalysts in H,SO,, HCI, a 86 organic compounds on Pt anodes, a 191 0, in polycrystalline Rh 85 phenol on Pt and graphite anodes, a 134

AIROF, pH dependence, a 32 Alcohols, aliphatics, hydrogenation over Ru-Ni

membrane catalysts, a 135 37

for H, photoproduction, a 87 oxidation at Pt-SPE, a 134

oxidations by Ru complexes, a 140 by Ru(V1) and (VII), a 195

phenol, adsorption, oxidation on Pt and graphite anodes, a 134

2-propanol, photocatalytic dehydrogenation, a 87

and 0 s complexes, a 140 production from alcohol oxidation, a 140

Rh, a 140 88 35

n-decanes hydrocracking over Pt/AI,O,, a 137 n-heptane, aromatisation, a 35, 137 n-hexane, hydroisomerisation over Pd/zeolite, a 36 hydrogeneolysis over Pt/SiO, (EUROPT-I) a I93

35 n-pentane, isomerisations, a 137, 138

36

Rh/AI,O,, a 36 90 37

138 88

Pd/SiO,, a 193 36

glycerol at platinised Pt electrode, a

methyl, carbonylation over Rh/X zeolites, a

Aldehydes, ,r./?-unsaturated, hydrogenation by Ru

Aliphatic Acids, unsaturated, hydroformylation over

Alkanes, n-butane, conversion over Pt-Mo/Y-zeolite, a C,-C,,. conversion over Pt/HZSM-S, a

methane, oxidation over Pt/support, a

reactions over Pt-Au/support, a 88 Alkene, -alkyne, hydrogenation over Pd catalysts, a

allene, hydrogenation, low pressure over

arylation by Pd catalysts, a ethylene, pretreatment effect on Rh/Y zeolite, a I-heptene. hydrogenation over Pd catalysts, a

propylene, hydrogenation over Pt/SiO,,

Alkynes, alkene, hydrogenation over Pd catalysts, a 2-butyne- 1,4-diol, hydrogenation for y-keto acid

2-octyne hydrogenation with I-heptene over Pd catalysts, a 138

Ally1 Chloride, reduction at platinised Pt electrode, a 33 Amides, N-alkylation by RuCI,(PPh,)?, a 90 Amines, secondary, synthesis, from primary, a 38 Ammonia, catalytic oxidation gauzes 109 Arenes, a 38 Aromatisation, n-heptane on PtKL, P

I hexene, hydrogenation by Pt catalysts, a

production, a 39

Arora-Matthey, 20th Anniversary 53 Arsenic, environmental sampling, a Arylation, by Pd complex catalysts, a Aryltrimethyltins, synthesis, over “ligandless” Pd, a

Beam Leads, Ti/Pt/Au, failure suppression, a Benzene, hydrogenation, a

Benzoic Acid, hydrogenation over Pd/C, a Book Reviews, Amorphous Metallic Alloys

photocatalysed hydroxylation by RuO,/TiO,, a

Boussingault, history Catalysis in C , Chemistry Catalysis Volume 6 Chemistry of Ruthenium Phase Diagrams of Precious Metal Alloys

136 89,90

139

91 38

136 193 106 189 21 5 2

177 108

TO VOLUME 28

Page Bronzes, (RE)Pd,S,! preparation, characterisation, a 84 1.3-Butadiene. reactions over platinum metals, a 90, 194

Cancer, antitumour drugs 157,168 chemotherapy, Pt complexes, symposium 14

Carbon, isotope exchange with H, over Pt, Pd catalysts. a

Carbon Oxides, CO. adsorption, a I93

31, 138 chemisorption, a 139 conversion under transient air/fuel ratio, a 35 detection by Ru(I1) octaethylporphyrin, a 137 oxidation, a 139, 193 reaction with H, over Pd/TiO,, a 138 from low heat value gas combustion,

reduction, a 36 I93 90 39

Carbonylation, methanol, by Rh/X-zeolites, loading, a 37 Carboplatin 14, 157, 168 Carboxylic Acids, decarboxylation by platinised

Catalysis, asymmetric, a 90, 139

21 etching of gauzes in NH, oxidation I09 future predictions 150 heterogeneous, a 35,36,37,88,89, 137, 138, 139,

193, 194 homogeneous, a 38,39,89,90, 139, 140, 194, 195 hydrogenation, novel electronic effects, in 98 impregnation and drying processes, a 194 organometallic, 2nd Intl. Platinium Metal Conf. 168 recent advances 52 2nd Europ. Symp. 20

35, 137 conference 22 high temperature durability trial 174

combustion, review 12, 193 Iridium Complexes, IrClt-, a 194

reactions I68

CO,, adsorption on coal, a produced in fuel cell, a reaction with H, to form methyl formate, a

TiO,, a 34

bimetallic phase transfer, a 39 in C , chemistry, book review

Catalysts, automotive exhaust, a

lIr(CO)?q’-C5Me5 I , in hydrocarbon

Ir carbonyl/Al,O,, preparation, a 37

0 s carbonyl/Al,O,, preparation, a 37

Osmium Complexes, for aldehyde hydrogenation, a 140

Os,(CO),,/AI,O,, SO,, TiO,, chemisorption

Os/SiO,, Fischer-Tropsch, for olefin of CO, 0,, a 139

homologation, a 138

alkyne-alkenes, a 36, 138 Palladium, black, hydrogenation of

colloidal Pd hydrosols/support, a 35 comparison of heterogeneous and

homogeneous, a I94 for alkene arylation, a 90 for heterocycle synthesis, a a9 for NaHCO, reduction, a 34 Pd-Sb-KOAc, Pd-Bi-KOAc, for

acetoxylation, a 194 surfaces, catalytic chemistry under UHV, a 88 wire, for CO, hydrocarbon oxidation, a 193

89 Pd-Rh, H, adsorption in H,SO,, HCI, a 86

synthesis, a 38 for olefin arylation, a 89 with reducing potential, a 38 Pd(I1) azo complexes, nitrobenzene

hydrogenation, a 139 PdCIi-, a 194

Palladium Alloys, Pd-0-Zr, for methanation, a

Palladium Complexes, for N-heterocyclic


Catalysts (contd) Page PdCI,-CuCI, for butadiene-1.3 oxidation, a 90 (n-C,H,PdCI),, for Me$ reaction with

nitrobenzene, a 139 [PdCI,(PhCN),I, organic syntheses 168 Pd/y-Al,O,, Pd/CeO,/Al,O,, for CO,

hydrocarbon oxidation, a 193 Pd/activated C, modified, for alkyne-alkene

hydrogenation, a 138 Pd/C, for benzoic acid hydrogenation, a 193 Pd/C, Pd/PQ, for H, C isotope exchange, a 193

89 Pd/MgO, ESR study, a 36 Pd/PS, preparation and use, a 36 Pd/RE oxides, adsorption, catalytic

activity, a 138 Pd/SiO,, reactions, a 138, 193 Pd/SiO, gel for hydrogenation of

alkyne-alkenes, a 36 Pd/SiO, + zeolites, for H,/CO

conversions, a 194 bis(allyl)Pd/SiO,, a 138 Pd/stannic oxide, in TEA lasers I66 Pd/TiO,, activity for CO/H, reaction, a 138 Pd/zeolite, n-hexane hydroisomerisation, a 36 bis(allyl)Pd/X-zeolite, Y-zeolite, a 138 Pd-Cu/zeolite, for propylene oxidative

acetoxylation, a 89 Pd-Cuhordenite zeolite, toluene

disproportionation, a 36 Platinum, modified for hydrogenation study, a 88

wire for CO, hydrocarbon oxidation, a 193 Platinum Alloys, hydrocarbon reactions, a 194 Platinum Complexes, Pt(NH,):+, a 194

PtCl,-4PbC,,, for water gas shift reaction, a 33 PtCI,(PPh,),-SnCI,-Et,N, a 38

Pt-Au/Aerosil, clusters, a 88 Pt/AI,O,, hydrocracking of n-decanes, a 137

in I.C.E., deactivation, a 137 methane oxidation, a 35 mufRers. for diesel engine exhaust

purification. a 88 optimisation during pentane isomerisation, a 137 radial profiles, a 137

Pt/yAl,O,, Pt/CeO,/AI,O,, for CO, hydrocarbon oxidation, a 193

Pt, Ag particles/Al,O,, C, SiO, metal-support

Pd/C-K,CO,, for furan production, a

. . intiriction, a

Pt-Pb/Al,O,, isomerisation of n-pentane, a Pt-Re/AI,O,, radial profiles, a (NH,),PtCl,, (NHJzPtCl6, Pt(NH,),CIJy-AI,O,,

MgO, SO,, properties, a Pt-Sn/Al,O,- CI, activity for n-heptane

reforming, a Pt/CdS powder, for H, production, a Pt/C, Pt/PQ: for H, C isotope exchange, a Pt/ceramic, in wood-burning stove WMgO, ESR study, a Pt/colloidal resin, for H, photoproduction, a Pt/SiO,, (EUROPT-1) for alkane hydrogenolysis,

for methane oxidation. a for propylene hydrogenation, a

Pt/SiO,-Al,O,, methane oxidation, a Pdstannic oxide, in TEA lasers Pt/support, for low heat value gas combustion, a Pt/colloidal hydrosols/support, a Pt/TiO,, clusters, a

for decarboxylation of carboxylic acids, a NaOH-coated for H,O photolysis, a

Pt-Au/TiO,, clusters, for hydrogenolysis, a Pt/KL, PthJaX, for n-heptane aromatisation, a Pt/Mo/Y-zeolite, activity in n-butane

Pt-Ru/HY-zeolite, for Fischer-Tropsch, a Pt/HZSM-5, for n-alkane conversion, a Platinum Metals, additions to coal, a

conversion. a


88 138 137

137

35 34 193 115 36 136

a193 35

193 35 166 36 35 88 34 135 88 137

88 36 35 193

Catalysts (contd) Page

in combustion, a 193 ultrafine, organic syntheses, a 139

syntheses, 1980 study, a 89

for CI, evolution, a 33

Platinum Metal Complexes, in organic

Platinum Metals/Ce/Al,O, beads, three-way - _ catalysts, a 35

Platinum Metals, Oxides/IiO,, for benzene hvdroxvlation. a 136

Platinum Metalh-CdS, n-InP, n-SrTiO,, n-TiO,, electrical contact properties, a 87

Rhodium, for hydroformylation, a 140 193

Rhodium Alloys, Pd-Rh, H, adsorption, in H,SO,, HCI, a 86

Rhodium Complexes, for asymmetric reactions, a 90, 139

for photocatalysis, a 87 90

Rh(CO),C,,, for water gas shift reaction, a 33 lRh(COD)LI, IRh,(COD),L'I, for H,

transfer reaction, a 140 Rh( I)triphenylphosphine/ion-exchange

material, for hydrogenation, a 138

Rh/AI,O,, low pressure allene hydrogenation, a 36 Rh/y-Al,O,, RVCeO,/AI,O,, for CO,

hydrocarbon oxidation, a 193 tris(allyl)Rh/Al,O,, a 138 Rh-K/Cr,O,/pAl,O,, for toluene steam

Rh-coated CdS, in artificial photosynthesis, a Rh/SiO,, Fischer-Tropsch, for olefin

Colloidal Rh hydrosols/support, a 35 RhCI,/TiO,, in CO-H, reaction, conditions, a Rh-Ag/TiO,, SMSI effect, a 37 Rh/X-zeolite, in methanol carbonylation,

loading effects, a 37 tris(allyl)Rh/X-zeolite, a 138 Rh/Y-zeolite, for ethylene hydroformylation,

pretreatment effects. a 37 Ruthenium, RuO, for coal oxidation, a 37, 140 Ruthenium Alloys, for hydrocarbon reactions, a 194 Ru-Ni, membrane, for alcohol hydrogenation, a 135 Ruthenium Complexes, for aldehyde

hvdroaenation, a 140 Ru(1l)bisdiazadiimines. MV photoreduction, a 35 Ru(bpy)i+. polymer pendant electrode, a 88 Ru(bpy)i+ - peroxydisulphate, photo-

oxidation, a 192 IRu(bpy),(CO)CII+, a 38 Ru(bpy),XY"+, quantum yields, a 192 Ru-Co for hydroformylation. a 140 Ru and Co carbonyls. for y-keto acids, a 39 HRu,(CO);,, HCO,Ru,(CO);,, for alkyl

formate production, a 39 RuCI,(PPh,),, a 38.90 RuCI,( 1,3-bis(4-methyl-2-pyridylimino)-

isoindolines for alcohol oxidation, a 140 Kf[RuH,(PPh,),(PPh,C,H3l-, in

hydrogenations 168 I RuO,l-. IRuO,l'-, IRuO,(bipy)CI,I as

oxidants. a I95 Ru-Rh, bimetallic, a 90

194 Ru/Al,OJSiO,. a 37 Ru-Co/Al,O,, SO,, studies, a 37 [Ru,(CO),J/AI,O,, MgO, cluster effects, a

wire, for CO, hydrocarbon oxidation, a

[Rh'(CO),Br,l- in CO/CO, fuel cell, a

Rh-Ru, bimetallic, homogeneous, a 90

dealkylation, a 89 192

homologation, a 138

37

Ru/AI,O, + promoter, in methanation, a

37 [H,Ru,(CO),,I/AI,O,, MgO, cluster effects, a 37 RuS,-CdS, photocatalysis, a 192 Ru(lI)triphenylphosphiie/ion-exchange material,

for hydrogenation, a 138 RuO,/polypyrrole, for H,O photodissociation, a 87 Ru0,-polybrene, for 0, evolution, a 192

204

Catalysts (contd) Page 38

139 138

RuCI,/PR,, for secondary amine synthesis, a Ru/SiO,, deactivation, CO oxidation, a

RuCI,/SiO,, for benzene, cyclohexene

Ru/support for syngas conversion to ethylene, a 194 Ru0,-TiO, colloids, 0, evolution, a 192 RuO,DiO,, paramagnetism, a 139 Ru/zeolites, CO, H, chemisorption, a 139

Fischer-Tropsch, a 89, 194 Ru-Pt/HY-zeolite, for Fischer-Tropsch, a 36 RdZSM-5, synthesis gas conversion, a 38

Cells, semiconductor-metal/SPE/Pt, a 87 Chemisorption, CO, 0, on 0 s carbonyl clusters, a 139

H, on Pd foil, film, a 31 suppression on Rdzeolites, a 139

190

electrode, a 33 33

Chromium Alloys, plastic, with Pt, Pd, Ir, Ru additions. effect on anodic dissolution, a 191

Cisplatin 14,157, 168 Coal, effects of catalyst addition on CO,

adsorption, a 193 indirect liquefaction over Ru/support, a 38 oxidation, a 37, 140

Coatings, Pd-Ni 54, 194

Combustion, catalytic, review 12, 193 Compton Profile, in Fe, measured by "'l'"Ir nuclei, a 193

Fischer-Tropsch, for o l e h homologation, a

hydrogenation, a 38

inorganics, organics, on Ru(001). a Chloral Hydrate, reduction at platinised Pt

Chlorine, evolution on platinum metals, a

Composite, ZGS Platinum "Trim" 7

Conference, cancer chemotherapy 14 Catalysis by Metals 20 Fuel Cells 19, 165 Hydrogen in Metals 13 2nd Intl. Platinum Group Metal Chemistry 157, 168 2nd Intl. Platinum Seminar 22 Thermal Conductivity 164

34 effects on Pd contacts, a 91 H, detector for pipes, a 195 photo, of n-RuS, single crystals, a 192 protection, a 90

Cracking, hydrocracking, alkanes, a 137 Crystallisation, 0 s dichalcogenides, single

crystals, a 191 84

190 191 85

38, 140

Corrosion, behaviour, Ti-Pd, ion implantation, a

in amorphous Pd-Si alloys, a Ru-Cu alloy single crystals, a Ru dichalcogenides, single crystals, a

Cyclohexene, reactions over platinum metals, a RuS, single crystals, properties, a

Dehydrogenation, 2-propano1, photocatalysis, a 87 Deltalog, thermocouple calibration monitor 107 Detectors, film thickness, calibration, a 136

hydrogen, a 141, 195 atomic, a 35

88 86

H,. a 86, 132, 133 137

Diesel Engines, exhaust pollution control, a Diffusion, gas electrode, C,Pt activated, a

DNA, relaxation by OsO, probe, a

Electrical Contacts, Ta-lr, in Schottky barriers Pd alloy, wear and friction, a Pd connectors, corrosion effects, a Pd inlay coupons, corrosion effects, a

52 195 91 91

Pd-Ni coatings 54 Pt,Rh,Ru for Schottky junctions, a 87 Ti/Pt, blistering during gas anneal, to

GaAs/AI-Ga--As), a 91 Ru-Cu alloys 62

164 33, 34, 86, 87, 134, 135, 191, 192

Electrical Resistivity, with temperature, of Pt Electrochemistry, a

Electrochromism, iridium oxide hydrous films Electrodeposition, 0 s on Co, Cu, Fe, Ag, a

PdNi, mechanical, corrosion properties, a Pd-Ag alloys from ammoniacal electrolytes Pt on Co, Cu, Fe, Ag, a Ru, from sulphamate, a hydrated Ru oxide films, a

Electrodes, anodes, Pt, organic adsorption on, a impressed current, Pt clad Nb, a Pt and graphite, phenol behaviour, a RuO,/ZrO,-coated Ti, 0, evolution at, a

C, gas diffusion, Pt corrosion of, a cathodes, Pd-Zr, for H, evolution from

Pd. anion erowth. in DMSO. zero charge H.O. a

potentid, a I

Pd, Pd alloy, H chemical potential, a Pd, H, uptake in, a Pd-PdO, urease, for urea detection, a Pt, in alkaline fuel cells

anion growth, in DMSO, zero charge

hydrous oxide formation, a + Hg adatoms, catalytic oxidation, a

potential, a

Pt-PVAA/GC, platinum microparticles,

Page 56 35

1Y5 117 35 88

136 191 90

134 87 86

87

1Y 1 192 31

193 46

191 191 86

activity, a 134 Pt-SPE, a 33,134, 191 platinised CdS, for H, evolution, a 87

photo, RuO,/n-GaP for H,O photo- platinised Pt, a 33

dissociation, a photoresponsive, Ru(bpy):+ coated, a Ag/GaAs/Ru(bpy):+, Raman scattering, a thin film, tris(2,2'-bipyridine)Ru(II)Pt, a

Electrolytes, ammoniacal, for Pd-Ag electro-

Electronics, Pd-Ni plating in Emission Control, automotive exhaust

deposition

catalysts conference

Energy, solar cells, a Esters, from syngas by Ru-Rh, homogeneous, a Etching, acid, of Pt, inhibition by 0,, a

catalytic of Pt, Rh-Pt gauzes Ethylene, reactions over platinum metals, a

diesel engine exhaust, a

87 88 34 34

117 54, 114

150, 174 22 88 87 90

132 109

37,86,194

Films, Pd, transport properties, a 190 Pt on Si, stress, reflectivity, a 132 Pt and Ni on i 100 > Si, metallurgical, electrical

behaviour. a 132 Ru, a 141 Ru(I1) oxide, electrodeposition, a 136 Ta + Pd, H, absorption rate, a 84 thickness monitors, calibration, a 136

Fischer-TroDsch. reactions. a 36.89.138.194 Formaldehyhe, for H, photbproduction, a

'

Formic Acid, reactions with platinum metals, a Friction, of Pd electrical contact couples, a Fuel Cells

alkaline, for vehicle propulsion

electrocatalysts, a future predictions U.S. National Seminar, 1983, Florida

c o / o , , a

Furan, preparation, a

Gauzes, Pt, Rh-Pt catalytic etching

Glass, ZGS platinum "TriM" handling equipment Glasses, metallic, palladium, a

Glycerol, reactions at platinised Pt electrode, a

Pt in CO/O, fuel cell, a

superconducting, book review

87 86,87

195 165 46

90, 140 33

150 19 89

109 90

7 31,84

106 33


Page Halides, photooxidation, by RuS,, a 192 n-Heptane, reforming by Pt-Sn/AI,O,-CI catalysts, a 35 Heterocycles, synthesis, Pd catalysed, a 38,89 n-Hexane, hydroisomerisation over Pd/zeolite, a 36 I-Hexene, hydrogenation, by modified Pt catalysts, a 88 History, J. 8. Boussingault, book review 189

First organometallic compounds, Zeise's salt 76 Macquer and melting platinum 25 platinotype photography I78 Russian platinum coins 126 thermal analysis 125

I38 I93

aromatic, direct systhesis from syngas, a I94 long-chain, from Fischer-Tropsch reaction, a 194 rnultimetallic catalysts, conference 80

35 140 89

140 37

140 13, 31,84

Homologation, of olefins by Fischer-Tropsch, a Hydrocarbons, C,H,, I-hexene, toluene, oxidation, a

Hydrocracking, n-alkanes over Pt/HZSM-5, a Hydroformylation, aliphatic acids, by Rh, a

catalysts for, survey for 1980, a cyclohexene, by Co-Ru complexes, a ethylene. pretreatment of Rh/Y-zeolite, a

activation with COz for methyl formate

adsorption on Pd-Rh catalysts in H,SO,, HCI, a 86 on Pd-rare earth oxides, a 138

chemisorption, a 31, 139 detectors, a 141, 195

atomic, a 35 diffusion 86,132,133 ernbrittlement in Pd-Ag alloys, a 84 isotopes. exchange with C over Pt, Pd

catalysts, a 193 solubility in Pd, a I90

permeation in Pd electrodes, H chemical potential measurement, a 192

photoproduction, (I 87 from colloidal Pt, in Ru(bpy):+, a 136 at platinised CdS electrode, a 87 by Rh-coated CdS, a 192 by CdSIRuS,, a 192

34 from solar cells, a , 136

3 3 electrochemical. on Pd-Zr cathode. a 87 at Pt-PVAA/GC electrode. a 134 at Pt-SPE electrode, a 33

reaction with C O over Pd/TiO,, a I38 sensitivity of ZnO thin films with Pd salts, a I90 solubility in platinum metals under high pressure 158 transfer reactions over Rh complexes, a 140

36. 138 novel electronic effects 98 Pd(l1) azo complexes, a 139 over Pd-W, a 133

Pd/C. a 193 Pd/SiO,, a 193 Pt foil. a 86 Pt modified. a 88 Pt/SiO,, a 193 platinum metal nitrosyls, a 38

Rh complexes, asymmetric, a 90 Rh-, Ru-(PPh,),sulphonated complexes, a 138 Rh/AI,O,, a 36 Ru and 0 s complex catalysts. a 140 Ru-Ni membrane catalyst, a 135 RuCI,/SiO,, liquid-phase, a 38

Hydrogenolysis, alkanes on Pt/SiO, (EUROPT-I). a 193 Hydroxylation, benzene, by RuO,/TiO,, a 136

I-olefin, over Rh catalyst, a Hydrogen, absorption in Pd

production, a 39

from Na sulphite, platinised CdS, a

production. by water gas shift reaction, a

Hydrogenation, over Pd catalysts, a

platinum metal colloid/support, a 35

Ion, implantation. for Pd-Ti surfaces, a 34 Iproplatin 14. 157, 168

Page

graphic behaviour, a 135 hydrogen solubility in 158 """'lr nuclei. to measure Compton Profiles. a 193

Iridium Alloys, LalrSi,, superconductivity, a I34 Zr,olr,o, amorphous, electrical resistance, a 190

Iridium Complexes, review, a 86 Iridium Oxides, electrochromic, hydrous films 56

32 33

Isomerisatinn, reactions over platinum metals, a 35.36. 137, 138, 191

Iridium, compound, radioactive. thermochromato-

films. AIROF, SIROF, pH dependence, a Iridium Perovskites, MLaMglrO,. properties, a

Johnson Matthey Collection, American platinotype exhibition I78

Ketones, production, a 140,195

Langmuir, Irving, history Lasers

Macquer, Pierre Joseph, history Maenetic Storaee

31 31.91, 166

Magnetism. OsTn y-Fe,O,. in recording discs RPd,Si. a Pd-Cu-Fe-Si amorphous alloys, ordering, a Pd W. changes during hydrogenation. a R5Pt, compounds, a Pt-Co thin films Pt-Fe alloys. a rhodium borides, ternary, a CeRuS, . a RuOhiO, . paramagnetism. a

Matthey Rustenburg, solvent extraction plant Medical, uses of platinum group metals 14, Methanation, over platinum metals, a Methane, oxidation, over Pt/support, a Methyl Formate, production over Ru complexes. a

25 I I6 I I6

85, 133 84

133 31 75

84, 190 85 3 2

139 2

157. 168 89, 194

35 39

Naphtha, production from syngas over Ru, a Nitrobenzene, reactions over platinum metals Nitrogen Oxides, NO, adsorption on Pt(410). a

I94 98, 139. 191

31 emissions, catalytic control 22. 174

Olefins, reactions over platinum metals, a 35, 89, 138, 195 Organometallie Complexes 32,38

in organic syntheses, 1980 survey, a 89 Pd, Pt complexes, properties, a 85 platinum anti-tumour drugs 14 Zeise's salt. history 76

Osmium, hydrogen solubility in 158 in magnetic discs I I6 Os(V1). Os(VII1) acidic behaviour, a 87 thick targets, cross sections, a I34

85 Osmium-Iron, phase diagrams, a 85

chemical oxidation, a 135

Osmium Alloys, Osmium-Hafnium, phase diagram, a

Osmium Complexes, Os(bpy):+, Os(phen):+ electro-

0 s dichalcogenides. P 191 PPh,M,lOs(NO)CI,l, preparation. a 33 0s-S-CO clusters. synthesis, a 191

Osmium Tetroxide, for electron microscopy, a I36 probe for DNA. a 137

Oxidation, alcohols, a 134. 195 ammonia, catalytic gauzes I09 1.3-butadiene over PdCI,-CuCI,, a 90 catalysts for, 1980 survey, a 89 CO. a 139, 193 coal, by RuO,. a 37, 140 formic acid on Pt electrode, a 86

33

I95

glycerol at platinised Pt electrode, a methane, over Pt/support, a 35 olefins to ketones. over Pd(I1) salts, a


31 134

Pd.Pt thin films on silicides, a phenol on Pt and graphite anodes, a

- - chemisorption on 05 carbonyl clusters, a evolution from RuO, systems, a inhibition of Pt acid etching, a interaction with Pt(100). a reduction at Pt electrodes, a

Oxvaen, adsorotion over olatinum metals. a 36,85, 138 139

87, 192 132 173

Palladium, absorption of hydrogen

Pd-Mo, cluster PrPd,, a (RE) Pd,S, bronze, a

thin, on silicides, oxidation, a transport properties, a

foil, H chemisorption on, a H, diffusion in, colour effect, a H solubility in in As environmental sampling, a in solar cells, a in ZnO film, H, sensitivity, a overlayers on Ta films, H, absorption in, a a-palladium solubility of H,D,T in, a Pd(II)ion, hydrolysis, a Pd/n-GaAs, growth, a

electrical contacts, wear, friction, a Palladium-Beryllium, metallic glasses, a Palladium-Boron, metallic glasses, a Palladium-CoDDer-Hydrogen. suuer-

addition to steel, a compound, [ Pd(NH,),CI,I, precipitation, a

films, H chemisorption on, a

Palladium Alloys, absorption of hydrogen

.. ~ - . conductivity, a

Palladium-Copper-Iron-Silicon, amorphous, a 84 EuPd,Si,, magnetic susceptibility, a 133 Palladium-Gold-Silicon, amorphous crystallisation

33, iji

13 84 33

I68 32 86 31 31

190 31

132 158 136

39, 195 190 84

190 192 91 13

I95 31 31

133

behaviour, a 133 Palladium-Hydrogen-Silver, structure, electrical

resistivity at high H, pressures, a 135 Palladium-Hydrogen-Zirconium, amorphous,

crystalline phases, a 133 Palladium-Iron, magnetic susceptibility, by

SQUID, a 133 Palladium -Nickel, coatings 54, 114 Palladium- Phosphorus 106 Pd,,Pt,,. H, diffusion in, a 86 Palladium-Silicon, amorphous, crystallisation, a 84 Palladium-Silver, for electrodeposition 1 I7

H embrittlement, a 84 Palladium-Titanium, surfaces, ion implanted, a 34 Palladium-Tungsten, electrical, magnetic

properties during hydrogenation, a 133 Palladium-Zirconium, amorphous. a 87. 133

Palladium Complexes, organometallics preparation, . . properties. a 85

Palladium Hydride, H, diffusion in, activation volume, a*.

Palladium Sdicides, formation, for solar cells, a Pd,,Si,,. H absorption in, a RPd,Si. magnetic properties, a

Paraffins, branched-chain, by Fischer-Tropsch, a pH, dependence of Ir oxide films, a Phase Changes, in RE-rhodium ternary borides, a Phase Diagrams, 0s-Hf, a

0s-Fe. a Au-R-Rh, at I00O0C, a Pt-Ir-Ru. at 1400°C. a

133 39 31 85 36 32 85 85 85

132 132

Pt-Pd-Ru, at 140O0C, a 132 Pt-Ru-Rh, at 14OO0C, a 132 platinum metal alloy systems, book review 108 Ho(Rh,_,Ru,),B, at >1.3K, a 134 Ru-Fe. a 32


Page Pheromones, production, over Pd catalysts, a 89 Photocatalysis, a 34, 87.88. 135, 136, 168, 192

future predictions 130 Photography, platinotype, history I78 Photo-Kolbe, reaction, a 34 Plating, Pd-Ni 54, 114 Platinotype. photography, history 178 Platinum, acid etching, a 132

activation of C electrode, corrosion effect, a 86 anodes. organic adsorption on, a 191 beam leads, Ti/Pt/Au, a 91 cladding on Nb impressed current anodes, a 90 coins, Russian, history I26 colloidal, reactions of MVzf, MV+ and H,, a 191 compounds, lanthanides, magnetic properties, a 3 1

clusters

radioactive, thermochromatographic Pt-Au, the first, a

behaviour, a electrode + Hg adatoms for HCOOH

oxidation, a films, Cu on, a

on Au colloidal, for calibration, a on Si, stress, kinetics, a on silicides, oxidation, a

foil, hydrogenations of C,H,, C2H, on, a hydrogen solubility in hydrous oxide formation, a laser-induced deposition on InP, a melting, early attempts, history Pt( loo), reaction with 0,, phases, a silicide formation in Pt/Ni/Si, Ni/Pt/Si, a surface composition after polarisation, a thermal diffusion in n-type Si, a

Platinum Alloys, Platinum-Cobalt, magnetic thin

Platinum-Gold-Rhodium, phase diagram, a Platinum-Iron, magnetic properties,

Pds,Pt19, H, diffusion in, a Platinum-Rhenium, properties, a Platinum-Rhodium, cyclic voltammetry on, a

surface composition after polarisation, a

films

anisotropy in, a

Platinum Complexes, in cancer chemotherapy, symposium

organometallics, preparation, properties, a [Pt(dien)II [Pt(dien)I,lI,, a lPh,Asl [Pt(SnCI,) (1,5-cod)l, a IH,NCH,CH,NH~,.82 IF’t(C,O,),I. 2H,O,

ID conductor, a

168 I90

135

86 31

I36 132 31 86

158 191 31 25

132 132 135 I32

15 132

84, 190 86 84

135 135

14 85 32 85

32 Zeise’s salt, history 76

132 Platinum Metals Alloys, phase diagrams, a book review 108

methane, a 32 38

105 136

automotive exhaust 22, 150, 168 high temperature durability trial 174

CO, a 137 diesel engine exhaust, a 88 Pt/ceramic catalyst in wood-burning stove 1 I5 platinum metal nitrosyls, a 38

Powder Metallurgy, history, for platinum coins 126 Propylene, reactions over platinum metals, a 89, 193 Pyrroles, production over Pd catalysts, a 89

Platinum Metals Complexes, bis(dipheny1phosphine)-

nitrosyls, in pollution control, a

Pollution Control, As in water, detector, a Poisoning, lead, on Pd catalyst

Quinone, hydrogenation 98

Reduction, catalysts for, 1980 survey, a Refining, platinum metals, new Royston plant Resistors, RuO, thick film, a

89 2

39, 195

207

Page Review, bis(dipheny1phosphine)meth~e-platinum

group metal complexes, a 32 catalytic combustion 12,193 homogeneous asymmetric catalysis, a hydrocarbon reactions on bimetallic catalysts, a hydroformylation of unsaturated fatty acids, a IF, Rh complexes, a olefins to ketones with Pd(l1) salts, a organometallic complexes of Pt,Pd, a platinum metal nitrosyls in pollution control, a solar cells, a superconductivity in platinum metals and alloys transition metals in organic syntheses, a ultrafine metal particles in organic syntheses, a

Rhodium, compounds, ErRh,B,, ferromagnetism,

H,Ru,Rh,(CO),,, clusters, synthesis,

Rh-Er-Sn, crystal structure, a RE-Rh-B, phases, magnetism, a Ho(Rhl-xRuX)4B4, phase diagrams, a (Sm-Er) Rh,B, superconducting magnetic

Zr,Rh, superconducting film tunnel

superconductivity, a

structure, a

transitions, a

junctions, a hydrogen solubility in polycrystalline, 0, adsorption, a silicides, LaRh,Si,, La,Rh Si LaRhSi,, crystal

structure, superconducthli. a surface composition, aRer polarisation, a

Rhodium Alloys, Rhodium-Copper, single crystals, a Rhodium-Gold-Platinum, phase diagrams, a Rhodium-Molybdenum-Phosphorus, super-

Rhodium-Platinum. surface comwsition after conducting glasses

polarisation Rhodium Complexes, ~ R h 4 ( C o ) , , l , [ ~ 6 ( ~ ~ ) , 6 ~ ,

interaction with AI,O,, TiO,, TiO, + SiO,, a 138 iodopentaamminerhodium(lII), photoaquation, a 34 IRh(C,H,O,N),CI. H,OL [Rh(C,H602N,l . H,O, a 134

139 I94 140 86

195 85 38

136 63 89

139

32

86 133 85

134

85

32 158 85

134 135 190 132

106

135

Rh porphyrins, a 87, 136 review, a

compound, BaRul-,Co,O,-,, structure, a clusters CeRu,Si,, magnetic properties, a RuS,, single crystals, growth, properties, a n-RuS,, stability, anodic photocorrosion, a electrodeposition from sulphamate, a hydrogen solubility in H,Ru,Rh,(CO),,, clusters, synthesis,

[Ru(001)1 chemisorption on, a Ru(II), Ru(IV) in TiO,+ Ta, a vapour deposition, a

Ruthenium, chemistry, book review

structure, a

Ruthenium Alloys, Ho/Rh-.Ru.),B., phase . “ ... . ~

diagrams, a Ruthenium-Copper, for electrical contacts Ruthenium-Iron phase diagram, properties, a Ruthenium-Molybdenum-Phosphorus, super-

conducting glasses

methylviologen, a

Ru dichalcogenides, a pentamethylcyclopentadienyl di-Ru, chemistry, a Ru(phen):+, electrochemical oxidation, a 135

Ruthenium Complexes, Ru(bipy):+ reduction, a tri~(2,2~-bipyridine)Ru(II) quenching by

Ru,(CO),OI-H,! (&Me,),, a

86 177 86

168 32 85

192 88

158

86 190 134 141

134 62 32

106 34

135 19 I 191 191

Page Ruthenium Oxides, electrodeposition, a 136

39, 195

dissociation, a 87 37,140

Schottky Bamers 52.91 Schottky Junction, effect in air and H,, a 87 SIROF, pH response, a 32 SMSI, effects, a 37,138 Sodium Bicarbonate, reduction over Pd catalysts, a 34 Solar Cells, a 39,136,195

2 SQUID, for magnetic susceptibility in PdFe, InMn, a 133

84 115

Superconductivity, LalrSi,, crystal structure, a I34 Zr,,,lr,o, electrical resistance, a I90 Pd-Cu-H solid solutions, a 133 in platinum metals and alloys 63

RuO,, thick film resistors, TCR in Ru0,-polypyrrole films, for H,O photo-

RuO, for coal oxidation, a

Solvent Extraction, platinum metals, new plant

Steel, Pt effect on sulphide stress cracking, a Stoves, wood-burning, platinum catalyst in

Erkh,B,, a 32

Er-Rh-Sn. crvstal structure. a 133 (Sn-Er)Rh,B,, magnetic transitions, a 85

Rh-La-Si,’a 134 W R h , -.Ru,),B,, a 134 Zr,Rh films, tunnel junctions, a 32

Synthesis Gas, conversions over platinum metals, u 38.90.194

Tantalum, films + Pd, H, absorption, a Temperature Measurement, Deltalog thermocouple

monitor history nuclear thermometry, a

Thermal Analysis, history Thermal Conductivity, temperature values of

Thermocouples, platinum :rhodium-platinum platinum

history recalibration device

Thermoelectric Power, of Pd films, a Thick Films, RuO, resistors, a Thin Films, Ir oxide, electrochromic. hydrous

Ir-Ta, metal-semiconductor contact 0 s + y-Fe,O, sputtered, in storage discs Pd on silicides, oxidation, a Pd salts in ZnO, H, sensitivity of, a Pt, anodic Cu on, properties, a Pt-Co sputtered magnetic Pt on silicides, oxidation, a Zr,Rh superconducting tunnel junctions, a

Toluene, reactions over platinum metals, a Tritium, solubility in Pd, a

84

107 125 39

125

I64 61,195

125 107 I90

39, 195 56 52

116 31

190 31 75 31 32

36.89 190

I-Undecene, hydrogenation by Pt catalysts, a Urea, determination by Pd-PdO urease electrode, a

88 193

Voltammetry, a 32,34,135

Water, photochemical splitting, a 34,87,135,136 Water Gas Shin Reaction, a 33,37,38 Wear, on Pd electrical contacts, a 195 Willis, William, history 178 Wood, burning stove, Pt catalyst in 115

Young’s Modulus, glassy Pd-Si-H alloys, u 84

Zcise, William Christopher, history ZGS Platinum “TriM”


76 7

Documents

VOL. 28 OCTOBER 1984 NO. · UK ISSN 0032-1400 PLATINUM METALS REVIEW A quarterly survey of research on the platinum metals and of developments in their application in industry VOL