Homogeneous Catalysis

A part of 529-0502-00L Catalysis

Jeroen A. van Bokhoven, Marco Ranocchiari

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Dr. Marco Ranocchiari

Laboratory for Catalysis  and Sustainable Chemistry (LSK) OSUA/2045232  Villigen PSI Switzerlandemail: marco.ranocchiari@psi.ch tel: +41 (0)56 310 58 43

Fr, 10.45 – 11.30 HCI J 7

Prof. van BokhovenWe, 9.45-11.30 HCI J4

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Topics:1. Basic Concepts

Catalysis, Oxidative addition, reductive elimination, migratory insertion, elimination

2. Reactions with COa. Hydroformylation (Rh, Co, Ir)b. Carbonylation of alcohols (Monsanto Process)

3. Reactions with Olefinsa. Olefin oxidationb. Wacker process (olefin hydration)c. Carbene complexesd. Polymers by Metathesise. The Shell Higher Olefins Process (SHOP)

4. Homogeneous, heterogeneous and MOF catalystsa. Differences between homogeneous and heterogeneous catalysis (slides and script)b. Metal-organic frameworks (MOFs) - slides

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Learning Material and Books

Scripthttp://www.vanbokhoven.ethz.ch/education/catalysis.html

Basics:R. H. Crabtree, The Organometallic Chemistry of the Transition Metals, Wiley, 2009

Industrial Processes:G. P. Chiusoli, P. M. Maitlis, Metal-catalysis in Industrial Organic Processes, RSC Publishing, 2008

Industrial perspective with some details on the chemistry:S. Bhaduri, D. Maitlis, Homogeneous Catalysis - Mechanisms and Industrial Applications, Wiley, 2000

Details on homogeneous catalysts:Piet W. N. M. van Leuween, Homogeneous Catalysis - Understanding the Art, Kluwer Academic Publishers

Online:Catalysis - An Integrated Approach to Homogeneous, Heterogeneous and Industrial CatalysisEdited by: J.A. Moulijn, P.W.N.M. van Leeuwen and R.A. van Santen

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The EXAM

30 min Oral Exam

20 min heterogeneous10 min homogeneous, overlap and MOF catalysts

The GOALS

- Understanding and discussing catalytic processes based on homogeneous complexes

- Understanding and learning catalytic cycles of transition metal molecular catalysts

- Understanding the differences between homogeneous and heterogeneous catalysts and supported molecular catalysts.

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AMMONIA SYNTHESIS

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3/2H2+1/2N2 NH3

• "detonator of the population explosion"

• produces 450 million tonnes of nitrogen fertilizer per year

WithoutCatalyst

WithCatalyst

ΔH

reaction coordinate

METATHESIS OF OLEFINS

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Catalysis is a phenomenon related to kinetics!A Catalyst opens a new reaction pathway:

The equilibrium position is determined by by thermodynamic parameters of the reaction and NOT by the presence of the catalyst (ΔG0 < 0 → K > 1).

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Heterogeneous CatalysisC2H4 + H2 C2H6

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Pt surface! →!!!!

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THE IMPORTANCE OF CATALYSIS80% of all materials you see in your everyday life have seen at one point or another a catalystHETEROGENEOUS CATALYSTS

source: http://www.essentialchemicalindustry.org/processes/catalysis-in-industry.html

Process Catalyst Equation

Making ammonia Iron

Making synthesis gas (carbon monoxide and hydrogen)

Nickel

Catalytic cracking of gas oil Zeolite Produces:a gas (e.g. ethene, propene)a liquid (e.g.petrol)a residue (e.g. fuel oil)

Reforming of naphtha Platinum and rhenium on alumina

Making epoxyethane Silver on alumina

Making sulfuric acid Vanadium(V) oxide on silica

Making nitric acid Platinum and rhodium

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ZEOLITE CATALYSTS

source: http://www.essentialchemicalindustry.org/processes/catalysis-in-industry.html

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Process Catalyst Equation

Catalytic cracking of gas oil Zeolite Produces: a gas (e.g. ethene, propene) a liquid (e.g.petrol) a residue (e.g. fuel oil)

Reforming of naphtha

Platinum and rhenium on zeolite

Disproportionation of methylbenzene Zeolite

Dealkylation of methylbenzene Zeolites

Making cumene (1-methylethyl)benzene< Zeolite (ZSM-5)

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HOMOGENEOUS

source: http://www.essentialchemicalindustry.org/processes/catalysis-in-industry.html

Manufacture Catalyst Equation

Ethane-1,2-diol Sulfuric acid

2,2,4-Trimethylpentane (iso-octane)

Hydrogen fluoride

Phenol and propanone Sulfuric acid

Bisphenol A Sulfuric acid

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HOMOGENEOUS Transition Metal-CatalyzedManufacture Catalyst Equation

Linear aldehydes from olefins (Hydroformylation of olefins)

Co/Rh molecular complexes

Acetic acid Rh and Ir with promoters CH3OH + CO → CH3COOHPolycyclopentadiene (metathesis) WCl6/WOCl4/Et2AlCl (Metton)

Polypropylene Titanocenes with MAO CH2=CH2-CH3 → [CH2–CH2]n | CH3

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HYDROFORMYLATION OF OLEFINS

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Active site in the MOF*:

Linear :branched ratio determined by:- Steric hindrance (the reaction

is under kinetic control)

*This active site has already been synthesized for topology MIL-101(Al)

Question: Can we predict which functional

group/MOF should we have within the environment around the active site to improve linear/

branched ratio?

Reaction:

We hope that computations will give the

answer

R1+ CO + H2 R1

CHO R1

CHO+

linear branched

PPh2O

O

O

O

MOF

MOF

RhOC

COOCH

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Challenges in Catalysis

Photocatalytic and electrocatalytic water splitting for hydrogen production

CO2 reduction

Selective methane activation

Understand how to design catalyst structures to control catalytic activity and selectivity

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