Synthesis of Ce Gd O (CGO) nano ceramic for low temperature … 3/Issue 9/IJEIT1412201403_06.pdf · 2014-05-16 · (CGO) nano ceramic ... glass beaker and heated to evaporate on a

ISSN: 2277-3754

ISO 9001:2008 Certified International Journal of Engineering and Innovative Technology (IJEIT)

Volume 3, Issue 9, March 2014

26

Synthesis of Ce0.8Gd0.2O2 (CGO) nano ceramic

powders by citrate-nitrate route of auto-combustion

for low temperature solid oxide fuel cell (SOFC)

applications Y. M. Alyousef*, F.S.Alenazey, M.Ghouse, G.N.Almutairi and A.E.Aldossary

Y.M.Alyousef, email: [email protected], F.S.Alenazey, email: [email protected], M.Ghouse, email: [email protected], G.N.Almutairi, email: [email protected],

A.E. Aldossary, email: [email protected]

Energy Research Institute, King Abdul Aziz City for Science and Technology (KACST) PO.Box.6086, Riyadh 11442, Saudi Arabia

Abstract: In the present investigation, Ce0.8Gd0.2O2 (CGO)

nano powders were prepared by citrate-nitrate route of auto-combustion

with citrate to nitrate ratio 0.30since CeO2 based oxide has high

ionic conductivity; it is used as electrolyte for low temperature

SOFC application. Also the CGO powders are used for inter

layers due to their good electrical properties to enhance the

performance of SOFC cells. The as prepared powder was calcined

at 700oC for 6hrs to remove carboneous residues using Thermolyne

47900 furnace and characterized the powders using SEM / EDS ,

TEM , Particle size analyzer, XRD, DTA and TGA techniques and their

results are presented. The porosimetry analysis depicts that the

surface area the CGO powders was decreased from 70.31m2/g to

38.32 m2/g after calcination ofthe powder at 700

oC/6hrs.From

the by Debye Scherrer equation the average crystallite size of the

powderwas found to be around 13.86 nm for as prepared CGO

powder and around 18.52 nm for calcined powder. TGA studies

indicates that thereis no weight loss after temperature of 750oC

indicating completion of combustion.

Key words: CGO (Gd-doped Cerium Oxide), SOFC, Porosimetry,

CeO2, auto-combustion.

I. INTRODUCTION

The Solid oxide fuel cells (SOFCs) are prominent candidates of

power generators that covert chemical energy directly and with

high efficiency, into electricity while causing little pollution.

These power generating systems have attracted a considerable

attention because of their environment amity, and fuel flexibility

[1,2]. The current status of the development of a cell unit is

based on yttria-stabilized zirconia (YSZ) solid electrolyte

and electrodes consisting of Sr-doped LaMnO3 (Cathode)

and Ni-YSZ cermet (Anode) [3,4]. Among the cathode

materials reported (La, Sr) MnO3 (LSM) based perovskite,

due to their stability and high electro catalytic activity for

oxygen reduction at high temperatures, are the most

extensively studied and investigated materials for O2

reduction [5-9]. In spite of significant efforts have been put

until now by various researchers, fundamental questions on

the mechanism and kinetics of the O2 reduction reaction and

on the electrode behavior of LSM materials under fuel-cell

operation conditions still remain unsolved.

It is known that by decreasing the operating temperature

reduces both electrolyte conductivity and electrode kinetics

so the cell performance is hindered. In order to reduce the

increase in electrolyte resistance due to lower cell operating

temperature , it is common practice to reduce the electrolyte

(YSZ) thickness [10-13] or using high ionic conducting

electrolyte materials such as doped lanthanum gallate

(LaGaO) [14,15] and Gadolinium doped ceria (CGO)

[16,17]. Higher electrical conductivity of CeO2 material can

be achieved by doping with divalent or trivalent cations such

as ca, Y, La, Gd and Smetc [18]. While Dusasetre and

Kilner [19] reported that when 30wt% Gd0.1Ce0.9O1.95

(GDC) was added to the LSCF the polarization resistance

was decreased by four times, Murry et al [20] discovered

that the addition of 50% Gd0.2Ce0.8O1.9 (GDC) to

La0.6Sr0.4Co0.2Fe0.8O3(LSCF) produced a factor of about 10

times reduction in polarization resistance. However

performances are depending on the LSCF-GDC composite

cathode sintering and microstructure like grain size and

porosity and compositions [19-22].

It is reported by Leng et al [23] that the development of

LSCF GDC composite cathodes using glycine-nitrate

combustion method for low-temperature solid oxide fuel

cells with thin film GDC electrolyte. The polarization

resistance of pure LSCF cathode sintered at 975oC /2hrs was

1.2 Ωcm2at 600oC.The lowest polarization resistance of

0.17Ωcm2was achieved at 600oC for LSCF-GDC (40%-

60%) composite cathode.Several researchers have attempted

by different techniques [22-26] for preparing CGO materials

for SOFC cathode materials for their attractive electrical

properties. Many researchers have been trying to develop

new solid electrolyte materials with higher ionic

conductivity than YSZ at intermediate temperatures (500-

700oC), and doped ceria materials are promising [27].

The main design requirements for the Electrolyte material

[28] include:

i) Ionically conductive (should be characterized by

oxygen ion transport numbers close to 1

ii) Electronically insulating;

iii) Chemically stable at high temperature; iii) chemically

stable in reducing and oxidizing environments;

iv) Gas tight / free of porosity;

v) Production as a uniformly thin layer (to minimize

Ohmic losses);

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vi) Thermal expansion that matches electrodes; vii) Use

inexpensive materials.

In the present investigation, nano crystalline material of

CGO powders for using as inter layers / electrolyte in SOFC

cells were prepared by the auto-ignition technique since it is

a simple and more economical way of making nano powder

sand their characterization was carried out using SEM/EDS,

TEM , XRD, Porosimetry (particle size analyzer) , TGA /

DTA techniques.

II. EXPERIMENTAL

A. Preparation of Powders

The Ce0.8Gd0.2O2 (CGO) nano ceramic powders were

prepared by modified auto-combustion technique [23,29,30]

using Ce(NO3)3 6H2O (BDH),Gd(NO3)39H2O, Citric acid

(BDH)and distilled water. The precursor solution was

prepared by mixing individual aqueous solution of the above

chemicals in a molar ratio of 0.8: 0.2 respectively for CGO.

To the mixed all nitrate solutions, required citric acidwas

added. The citrate / nitrate ratio used in the present

experiments was 0.3. The solution was taken in a Pyrex

glass beaker and heated to evaporate on a hotplate using

magnetic stirrer until a chocolate colored gel was formed.

When the heating was continued further, the gel gets

completely burnt on its own and becomes light and fragile

ash. The ash was calcined at 700oC/6hrs in a Barnstead

Thermolyne 47900 Furnace (USA). Fig. 1 shows the flow

Sheet for the preparation of CGO Powder by auto-ignition

technique.Table 1 shows CGO powder samples prepared.

Fig 1- Flow Sheet for the preparation of Ce0.8Gd0.2O2 Powders

by auto-combustion technique [23, 29].

Table 1-Batches of CGO Powders prepared by auto-combustion

Sample No Cathode Powder

# 133 a # 133 b

Ce0.8Gd0.2O2 (CGO)

CGO: a: As prepared, b: calcined at 700oC/6hrs

B. SEM / EDS Characterization

Small amounts of the samples were spread on adhesive

conductive aluminum tapes attached to sample holders,

coated with thin films of gold and examined by the

Scanning Electron Microscope. The equipment used for

analysis was OXFORD INCA 250 Energy Dispersive X-ray

Analyzer (EDS) installed on Quanta 200 Scanning Electron

Microscope operated at 20KV. TheEnergy Dispersive X-ray

Analyzer (EDS) was used to determine the elemental

compositions at area and spot. Images at higher

magnification were collected on FEI Quanta 3DF SEM.

Imaging was performed in Secondary Electron (SEI) mode

only using an accelerating voltage of 20keV. Also some

CGO samples were also analyzed using another SEM

Machine -SEM / EDAX, NNL 200, Holland.

TEM Characterization

Some CGO samples were analyzed using TEM

Equipment, 200kV, TEM-2100F, JEOL, Japan at high

magnification to study their microstructures.

C. XRD Characterization

(a) A part of the samples were analyzed by X-Ray

Diffractometry (XRD) System, JDX 8030, JEOL Co., and

Japan for phase characterization. The X-ray Diffractometry

with CuKα radiation at 40KV and 35mA was used for phase

analysis with in a diffraction angle 2 theta range 10-70o and

particle size determination from X-ray line broadening

technique using the following Debye Scherrer Equation

[31]:

t = 0.9λ / B Cos Ø

where t = Average crystallite size in nm, λ = the wave

length (0.15418nm) of Cu Kα radiation, B the width (in

radian) of the XRD diffraction peak at half of its maximum

intensity (FWHM) , and Ø the Bragg diffraction angle of the

line, and B is the line width at half peak intensity.

(b) Also, the samples were analyzed XRD with

PANalyticalX'Pert PRO XRD, with Voltage = 40kV and

Current = 40mA using CoKα radiation (λ = the wave length

of 0.1789nm) for comparison.

(c)For comparison to find approximate average particle

size, the following equation was used:

DBET : 6 / (SBET x dth) [32] where DBET is the average

particle size in nm , SBETSurface area in m2/g and dth the

theoretical density of the material in gr/cc. [assuming that

the particles have spherical shape and uniform size]

D. Porosimetry Characterization

1. Particle Size Distribution

Particle size distribution analysis was done using particle

size analyzer Mastersizer 2000 manufactured by Malvern

Cerium nitrate

Gadolinium nitrate

Aqueous Solution

Citric Acid c/n = 0.3

Heating on Hotplate

(SolutionTemp.1000C)

Ash

Calcination of Ce0.8Gd0.2O2 Powders

at 7000C / 6hrs in air

Dried Gel

Gel Formation

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Instruments U.K. This instrument works on the bases of

laser diffraction and is equipped with Hydro 2000S liquid

feeder with a capacity of 50 to 120 ml. This feeder has a

built-in ultrasound probe with an inline pump and stirrer.

This instrument is capable to measure particle size

distribution within a range of 0.02 to 2000 μm. The distilled

water was used as dispersant. Sample was added to the

dispersant to have an obscursionlimit in the range of 5-20 %.

The calculation of particle size distribution was done using

Mie theory.The samples were analyzed with and without

using ultrasound probe. This instrument measures the

particle size distribution on the bases of volume of sample

particles.

2. Surface Area, Pore Volume and Pore size measurement

The surface area of samples was measured using

Autosorb-1C instrument manufactured by Quanta Chrome,

USA. Samples were taken in the range of 0.1-0.2 g in a cell

and were degassed at 300oC for 3 hrs to remove any

absorbed material on the surface. Nitrogen gas was used as

adsorbent.

The BJH Method cumulative adsorption has been used to

calculate pore volume cc/gr and pore size in oA. The surface

area (m2/g) of the as prepared powder and after calcinations

at 700oC have been calculated.

3. TGA / DTA Characterization

In order to determine the decomposition behavior of the

CGO samples, around 7-8mg of the samples were loaded in

an alumina crucible and put inside the thermo balance of TG

Machine (Perkin-Elmer Thermal Analysis). The thermal

decomposition behavior was studied up to 800oC that was

raised at a rate of ~10oC per minute. The Thermal

Gravimetric Analysis (TGA) and Differential Thermal

Analysis (DTA) of CGO powders plots are presented.

III. RESULTS AND DISCUSSION

A. SEM / EDS and TEM Characterization

Figures 2a–2b show the nano-sized particles observed by

Scanning electron microscopy from the Ce0.8Gd0.2O2 (CGO)

powder samples calcined under oxygen atmosphere at

700oC/6hrs which were prepared by auto combustion

technique using metallic nitrates. The SEM images show the

porous structure and consist of gas cavities. This porosity

resulted from the gases released during the reaction of citric

acid and nitrates. It is noted from the Figures that the

porosity of the calcined powders at 700oC reduced as per

expectation. Figures 2c, and 2d show the EDS patterns of

Ce0.8Gd0.2O2 powders before and after calcination

respectively. The Figures show the presence of Ce, Gd, C, O

peaks. Also analysis of elements present at point 1 and point

2 are given. The residual C element from the citric acid

probably that had not been combusted yet is shown in EDS

in the as prepared powder. However, C content has been

reduced in the calcined powders. By increasing the

calcinations temperature, Carbon content could be further

minimized.The SEM images of CGO powdertaken from

another Machine are shown in Figures 2e-2h. These images

indicate highly porous structure of the nano sized CGO

powders prepared from combustion technique. It is seen big

gas cavities formed in the CGO powder indicating chemical

reaction occurred during combustion.These SEM images are

similar to the others reported [33-35].

Fig 2 a SEM of CGO (As prepared #133a)

Fig 2 b SEM of CGO (Calcined at 700

oC /6hrs -133b)

Fig 2c EDS of CGO (as prepared) sample # 133a

Fig 2 d EDS of CGO (Calcined at 700

oC / 6hrs) sample # 133b

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Analysis: as prepared by CGO Powder

Analysis: Calcined CGO Powder

Spectrum C O Ge Ce Gd Total

P1 12 32.31 0 43.28 12.41 100

P1 8.38 27.83 0 50.45 13.33 100

Mean 10.2 30.07 0 46.86 12.87 100

Fig 2e SEM Images of CGO Powder #133a

Fig 2f SEM Images of CGO Powder #133a

Fig 2g SEM Images of CGO Powder #133b

Fig 2h SEM Images of CGO Powder #133b

Figures 3a -3d show the TEM micro-photographs of as

synthesized CGO powders. It is seen that at high

magnification the porous micro-structure appears for CGO

agglomerates. It is clearly seen that the nano-sized CGO

crystals are with uniform size and compact distribution. The

TEM images show the particle sizes are in the range of 10-

50nm.The TEM images seen here are similar to the authors

reported elsewhere [35].

Spectrum C O Ce Gd Total

P1 38.28 27.31 26.7 7.76 100

P2 32.03 31.15 28.5 8.27 100

Mean 35.15 29.23 27.6 8.02 100

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Fig 3a TEM Image 120K # 133a

Fig 3bTEM Image 200K # 133a

Fig 3c TEM Image 120K # 133b

Fig 3d TEM Image 200K # 133b

B. XRD Characterization

Figures 4a and 4bshow the XRD patterns with CuKα

radiation for the as prepared powder (#133a) and calcined

powders of Ce0.8Gd0.2O2 at700oC (# 133b) respectively. It is

seen from the Figures that the calcined powder has well

crystalline perovskite phase of Ce0.8Gd0.2O2.These results

are in agreement with other authors reported elsewhere

[27,30,36] forming pure CGO phase. The X-ray line

broadening technique scherrer’s equation was used the size

determination of small crystallites. The values obtained here

may not be true particle size. However it is seen that the

crystallite size were found to be 13.70nm for as prepared

CGO powder and 16.55nm for calcined powder with CuKα

radiation , as shown in Table 2. Table 2 -XRD Data to determine the average crystallite size of

the CGO powders prepared by auto combustion technique

With CuKα Radiation With CoKα Radiation

λ (Co) = 0.15418nm λ (Co) = 0.1789nm

S.no. B Crystallite size,

B Crystallite size,

FWHM t (nm) FWHM t (nm)

133a 0.58 13.7 0.6978 13.3

133b 0.48 16.55 0.4929 18.71

t = 0.9 x λ / B Cos Ø , B= FHHM in o, B =[FWHM x 22/7 ÷ 180 ]=

FWHM x 0.017460

(a) Sample # 133a

(b) Sample #133b

Fig. 4 XRD patterns of Ce0.8 Gd0.2O2 (CGO) Powders prepared by

auto combustion technique ( a ) As prepared CGO Powder (Top) ,

(b) calcined at 700oC/ 6hrs (bottom)- With CuKα Radiation

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Figures 5a and 5b show the XRD patterns with CoKα

radiation λ = the wave length (0.17898nm) for the as

prepared powder (#133a) and calcined powders of

Ce0.8Gd0.2O2 at700oC (# 133b) respectively. The crystallite

size were found to be 13.30 nm and 18.71 nm respectively

for as prepared and calcined powders. It is also seen that

there is some shift in the peaks and crystallite size is similar

to the peaks obtained with CuKα radiation. It is observed

that the crystalline size increase for the powder calcined at

700oC is not significant; it is only few nanometers

difference. It is well known that the numbers of factors are

responsible for the nanosize of the resulting powders. The

crystallite size of the as prepared powders depends on the

citrate to nitrate (c/n) ratio during combustion process.

20 30 40 50 60 70 80 90 100 110 120

2Theta (°)

500

1000

1500

2000

2500

3000

3500

Inte

nsity (

counts

)

Sample #133a

20 30 40 50 60 70 80 90 100 110 120

2Theta (°)

1000

2000

3000

4000

5000

6000

Inte

nsity (

counts

)

Sample # 133b

Fig. 5 XRD patterns of Ce0.8 Gd0.2O2 (CGO) Powders prepared by

auto combustion technique ( a ) As prepared CGO Powder (Top) ,

(b) calcined at 700oC/ 6hrs (bottom)- With CoKα Radiation.

C. Porosimetry Characterization

Table’s 3-6 show the surface area data, pore volume data,

pore size data and the particle size distribution (with

ultrasound and without ultrasound), average particle of the

prepared and calcined CGO powders as respectively. Table

3 shows that the surface area data of the CGO powders of as

prepared and calcined at 700oC. It is seen that the surface

area for as prepared powder was 70.31m2/gr and 38.32 m2/gr

for calcined powder respectively. The surface area reduced

after calcination due to increase in particle size as per

expectation.It is seen that the approximate average particle

size of the as prepared and calcined CGO powders are 14

nm and 26 nm respectively using the equation [32]. It can

be seen that these values are quite comparable with the

particle size values obtained from XRD data. Table 4shows

the pore volume data of as prepared and calcined CGO

powders using BJH method with adsorption and desorption.

It is seen that the pore volume values for prepared powders

and calcined powders at 700oC are 0.275 cc/gr and 0.143

cc/gr (desorption) respectively. Also, it is depicted that the

pore volume of calcined CGO powder prepared and calcined

powders are 0.218 cc/gr to 0.1012 gr/cc respectively for

adsorption .It is seen that for both the cases the pore volume

values of the calcined CGO powder reduced after

calcination This may due to may be due to sintering taken

place at high temperature (700oC) and subsequently

shrinkage might have occurred. Such observation is in

agreement with the others reported elsewhere [37, 38].

Table 3 -Surface Area Data of Ce0.8 Gd0.2 O2 (CGO) Powders

Sample ID Number

Surface Area (m2/g) Multipoint BET

Average particle size with [DBET = 6/dth x SBET ]

[ 32]

nm

133 a 70.31

12.60

133b 38.32

23.02

DBET = Average particle size, dth = density of CGO (6.8 gr/cc) and

SBET = Surface area, m2/gr

Table 4-Pore Volume Data of Ce0.8Gd0.2O2 Powders [pores with

radius less than 473.3Ao at P/Po = 0.973]

Sample

ID no.

BJH Method

Cumulative

Pore Volume

(cc/g)

133a Adsorption 0.218

Desorption 0.275

133b

Adsorption 0.1012

Desorption 0.1427

Table 5 shows the pore sizedata of the as prepared and

calcined CGO powders with adsorption and desorption

using BJH method.It is seen that the pore size increased for

clacined powders (adsorption) [37,38]. However, for

desorption the pore size is decreased for calcined powders.

Table 6 shows the particle size distribution (volume

weighed mean) of the CGO powders for with and without

ultrasound. It is seen that there is decrease in the average

particle size (volume weighed mean) for the calcined

powders at 700oC for both with ultrasound and without

ultrasound experiment. This may be due to sintering during

calcination. However the reason for this is not well

understood.So this requires further studies using suitable

technique. Table 5-Pore Size Data of Ce0.8Gd 0.2O2Powders

Sample ID no BJH Method Pore Size (°A)

133a Adsorption 14.36

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Desorption 19.57

133b Adsorption 16.05

Desorption 10.42

a: as prepared , b: calcined at 700oC/6hrs

Figures 6a and 6b show the particle size distribution for

the as prepared CGO powders for with ultrasound and

without ultrasound respectively from BJH absorption

experiments. It is seen that the particle size distribution is

relatively large with size as small as 0.15 – 1µm and as large

as about 600µm being present for with ultrasound and

without ultrasound respectively. Majority of the particle size

lies in the range of 10-130µm for with ultrasound and 10-

600µm for without ultrasound respectively and the volume

weighted mean (average particle size) of the powder

isapproximately 70.02µm, 45.92µm for without ultrasound

and with ultrasound experiment respectively.

Fig 6a - Particle size distribution of CGO Powder (as prepared) # 133a

[with ultrasound]

Fig 6 b - Particle size distribution of CGO Powder (as

prepared) # 133a [without ultrasound]

Figures 7a and 7b show the particle size distribution for

the calcined CGO powders at 700oC for with ultrasound and

without ultrasound respectively from BJH absorption

experiments. It is also seen that the particle size distribution

is relatively large, with size as small as 0.15 – 1µm and as

large as about 700µm being present for with ultrasound and

without ultrasound respectively. Majority of the particle size

lies in the range of 10-100µm for with ultrasound and 10-

200µm for without ultrasound respectively and the volume

weighted mean( average particle size ) of the powder is

approximately 60.72µm , 40.08µm for without and with

ultrasound experiment respectively for calcined powders.

Fig 7a - Particle size distribution of CGO Powder (Calcined at 700

oC)

# 133b [with ultrasound]

Fig 7b - Particle size distribution of CGO Powder (Calcined at 700

oC)

# 133b [without ultrasound]

It is seen clearly from the Table 6 and Figures 6 and 7

that the ultrasounds might have helped in breaking the large

agglomerates and brought the particle size distribution

narrower. With calcination temperature of 700oC the particle

size (agglomerate size) increases but with the help of the

ultrasounds the aggregates gets fragmented which indicates

the agglomerates are soft which is observed by the

preparation by either sol-gel or combustion synthesis.

Actually with increase in calcination temperature the

agglomerate size should increase and surface area should

decrease thereby.It is observed that evenif there is a chance

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of formation a soft agglomerates with higher calcination

temperature, the effect gets nullified after ultrasounds.

Table 6 -Particle Size Distribution of Ce0.8 Gd0.2 O2 (CGO)

Powders

Sample ID no. Volume Weighted Mean ((μm)

With Ultrasound

Without Ultrasound

133a 45.92 70.02

133b 40.08 60.72

D. TGA / DTA Characterization

Figures 8-9 show the Thermo Gravimetric Analysis

(TGA) and Differential Thermal Analysis (DTA) plots for

the gels of CGO in the temperature range of 20-

860oCrespectively for as prepared and calcined powders.

The DTA plot depicts that at low temperature at 25oC and

22oC the removal of physically adsorbed water occurred for

as prepared and calcined CGO powders respectively. The

TGA plot shows that the CGO powders exhibit quite low

total weight losses of 4% and 2.5% respectively for as

prepared and calcined powders respectively when heated up

to 810oC which suggests the occurrence of basically

complete combustion reaction during powder synthesis

CGO phase since mass loss process is stabilized.A drastic

weight lossis observed in the TGA curves between 250-

300oC can be possibly attributed to the decomposition of

metal-citrate complexes.This is confirmed with an weak

exothermic peak occurred at 325oC and 350oC in the DTA

curve for as prepared and calcined powders due to the

combustion of residual carbon of the decomposition of the

CGO dried powders respectively. The TGA data shows that

to obtain pure CGO powder, a calcination temperature

should be around 750oC. The results reported here are in

agreement with other authors reported elsewhere [39-41].

a) As prepared powder

b) Calcined powder at 700oC

Fig 8 DTA Plots of CGO powder

a) As prepared powder

b) Calcined powder at 700oC

Fig 9. TGA Plots of CGO powder

IV. CONCLUSIONS

The following conclusions are drawn from the present

investigation:

The Ce0.8Gd0.2O2 (CGO) nano ceramic powders for

cathodes were successfully prepared by auto combustion

technique with c/n ratio of 0.3.

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SEM and TEM images indicate that the Particle

size of CGOare in the range of 50-100nm.

XRD patterns show the presence of the perovskite

Ce0.8Gd0.2O2 phases.

Porosimetry analysis shows that the surface area of

CGO powder reduced from ~76 m2/g – 38 m2/g after

calcining at 700oC.

The volume weighed mean (average particle size)

of the CGO powder was approximately 40.07µm and

60.72µm for with and without ultrasound experiment

respectively for calcined powders.

The pore volume of the calcined CGO powders is

reduced.

A TGA plot indicates that there is no significant

weight loss after reaching temperature of 750oC which

indicates the completion of combustion and forming oxide

phase.

FUTURE WORK

It is worth mentioning that it is planned to fabricate NiO-

YSZ layers by tape casting and sinter at appropriate

temperature and cut to the size of single cells (MEAs) of

16mm diax 1.5mm thick and apply LSM and CGO layers as

electrolyte inter layer over NiO-YSZ surface and study their

electrochemical properties with and without CGO inter

layers. The results will be communicated soon.

ACKNOWLEDGEMENT

Author's thanks are due to Mr. Mahmoud Al-Manea, Dr.

Shahreer Ahmad, and Mr. Abdul Jabbar Khan, Technology

Center (TC), Saudi Arabian Basic Industries Corporation

(SABIC), Jubail, Saudi Arabia for providing SEM/EDS and

XRD analysis result of Cathode powder samples. Author's

thanks are due to Dr. Naseem Akhtar of Research Institute

(RI), KFUPM, and Dhahran, Saudi Arabia for providing

Porosimetry analysis of the powders.

Also, Author's thanks are due to Mr. Hussama Zahrani,

Mr.Bassam Aldrwesh and Mr. Mohammad Asiri of Energy

Research Institute, King Abdulaziz City for Science and

Technology (KACST) for their assistance during the

experiments.

Author’s thanks are due to Mr. Abu Hazza of Petroleum

and Petrochemicals Research Institute for providing XRD

patterns for CGO powders. Authors would like to thank

Mr.Raed of AERI for analyzing CGO powders using DTA

and TGA techniques. Authors also thank Engr. Abdul

Rahman and Engr.Abdulazeez Ibrahem Alromaeh of

National Nano Technology Research Center, KACST for

their help for analyzing our samples using SEM / EDAX

and TEM techniques.

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AUTHOR BIOGRAPHY

Prof. Yousef M. Alyousef received his Bachelor’s degree in Mechanical

Engineering from King Saud University, Riyadh, Saudi Arabia, in 1995,

and his MS in Nuclear Engineering at Purdue University, West Lafayette,

USA in 2000 and his Ph.D. degree in Mechanical Engineering at Carnegie

Mellon University, Pennsylvania, USA in 2004. He is Professor and

Director of Energy Research Institute at King Abdul-Aziz City for Science

and Technology (KACST), Riyadh. His research interest is mainly

focusing on the areas of renewable energy, Fuel Cell and Energy Efficiency

Prof. Alyousef has published several Technical Papers in the International

Journals and presented several papers in the International Conferences. He

has about 25 technical papers to his credit.

Dr. Feraih Alenazey is an Assistant Research Professor at Energy

Research Institute, KACST, and Riyadh Saudi Arabia. He received his PhD

degree in Chemical Engineering from UNSW, Australia, in 2011. He has

about 10 technical papers published in National and International Journals

and presented in international Conferences. He is working in the field of

hydrogen production, fuel cells and catalysis.

Dr. Mohammad Ghouse received his Doctorate degree (PhD) in

Metallurgical Engineering (1980) from the Indian Institute of Technology

(IIT) Madras, Chennai, India. He has a Master’s degree (M.Tech) in

Materials Science and Technology (1975), a Bachelor’s degree (B.Tech) in

Chemical Engineering (1972), from the University College of Technology,

Osmania University, and Hyderabad, India. Dr. Ghouse worked in the

Corporate R&D division of Bharat Heavy Electricals Limited (BHEL),

Hyderabad, India from 1980-1989 holding different positions. Dr. Ghouse

was a recipient of prestigious NRDC (National Research and Development

Corporation) Award with cash and a Citation in 1991 by the Government of

India, New Delhi, India.

Dr. Ghouse has served as an Assistant Professor during 1989-1990 in the

Department of Chemical Engineering, King Saud University (KSU),

Riyadh, Saudi Arabia, worked as a Scientific Specialist during 1991-1993

at Solar Programs, King Abdulaziz city for Science and Technology

(KACST), Riyadh, Saudi Arabia. He was promoted to an Associate

Research Professor in 1994 and as Research Professor in 2000 at Energy

Research Institute, KACST, Riyadh. He was actively involved in the

development of Phosphoric Acid Fuel Cells (PAFC), Proton Exchange

Membrane Fuel Cells (PEMFC) and Solid Oxide Fuel Cells (SOFC) since

1991.

Prof. M.Ghouse has published several technical papers in the National and

in the reputed International Journals and presented in National and

International Conferences. He has 50 technical papers and a patent to his

credit. He has supervised PhD thesis on Fuel Cells and Materials Science

and guided several MS and BS Projects.

Prof. M. Ghouse was an active member (1976-2000) and is a Life Member

(since 2000) of the Society for Advance-ment of Electrochemical Science

and Technology (SAEST), Karaikudi, Tamil Nadu, India, and International

Association for Hydrogen Energy, USA (since 1995).He reviews regularly

the technical papers published in the International Journal of Hydrogen

Energy , Journal of Energy, Journal of Energy Conversion and

Management.

Prof. Ghouse is the Editorial Board Member of World Journal of

Engineering since 2009. He chaired several National and International

Conferences. The biography Prof. M .Ghouse was published in Madison’s

Who’s Who 2010 (USA), and in International WHO'S WHO of

Professional 2010, 2012, (USA), and Marquis WHO’S WHO in the World

for the 15th (1998), 16th (1999),18

th (2001) Edns (USA), and Who’s Who in

Science & Engineering(USA), 2002.

His main areas of interest include: Hydrogen Energy, Fuel Cells (PAFC,

PEMFC and SOFC), Materials Science and Technology, Corrosion, Electro

Metallurgy.

Dr. Ghzzai Almutairi is an Assistant Research professor, Energy Research

Institute, King Abdulaziz City for Science and Technology (KACST). Dr.

Almutairi received his PhD degree in Chemical Engineering in 2013 at

Centre for Hydrogen and Fuel Cell Research, School of Chemical

Engineering, University of Birmingham, UK. His dissertation work was on

Solid Oxide Fuel Cell (SOFC), and his M.S and B.S. degrees in Chemical

Engineering from King Saud University at Riyadh.

Dr. Almutairi has been working on both Proton Exchange Membrane Fuel

Cell (PEMFC) and SOFC for the last 10 years at the Energy Research

Institute. He was actively working in the fabrication of SOFC and PEMFC

electrodes and their physical and electrochemical evaluations. He has

published about 10 technical papers in reputed International journals and

presented several papers in conferences.

His main interest is in the development of electrode materials for solid

oxide fuel cells and Lithium-Ion Battery applications.

Engr. Abdul Rahman E Aldossary received his BS degree in Chemical

Engineering from the King Saudi University, Riyadh, Saudi Arabia in

2006. He is actively working in the preparation nanoceramic powders used

for SOFC application and testing of SOFC mono cells.

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