Homogeneous Catalysis A part of 529-0502-00L Catalysis Jeroen A. van Bokhoven, Marco Ranocchiari !1 Dr. Marco Ranocchiari Laboratory for Catalysis and Sustainable Chemistry (LSK) OSUA/204 5232 Villigen PSI Switzerland email: [email protected] tel: +41 (0)56 310 58 43 Fr, 10.45 – 11.30 HCI J 7 Prof. van Bokhoven We, 9.45-11.30 HCI J4 !2 Topics: 1. Basic Concepts Catalysis, Oxidative addition, reductive elimination, migratory insertion, elimination 2. Reactions with CO a. Hydroformylation (Rh, Co, Ir) (including asymmetric hydroformylation) b. Carbonylation of alcohols (Monsanto Process) 3. Reactions with Olefins a. Olefin oxidation b. Wacker process (olefin hydration) c. Carbene complexes d. Polymers by Metathesis e. The Shell Higher Olefins Process (SHOP) 4. Homogeneous, heterogeneous and MOF catalysts a. Differences between homogeneous and heterogeneous catalysis (slides and script) b. Metal-organic frameworks (MOFs) - slides !3 Learning Material and Books Script http://www.vanbokhoven.ethz.ch/education/index 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 Catalysis Edited by: J.A. Moulijn, P.W.N.M. van Leeuwen and R.A. van Santen !4 The EXAM 30 min Oral Exam 20 min heterogeneous 10 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. !5 AMMONIA SYNTHESIS !6 METATHESIS OF OLEFINS !7 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). !8 Heterogeneous Catalysis Pt surface C2H4 + H2 !!!!!→ C2H6 ! !9 THE IMPORTANCE OF CATALYSIS 80% of all materials you see in your everyday life have seen at one point or another a catalyst HETEROGENEOUS CATALYSTS Process Catalyst Equation Iron Making ammonia ! Making synthesis gas (carbon monoxide and Nickel ! hydrogen) 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 ! source: http://www.essentialchemicalindustry.org/processes/catalysis-in-industry.html !10 ZEOLITE CATALYSTS 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) ! source: http://www.essentialchemicalindustry.org/processes/catalysis-in-industry.html !11 HOMOGENEOUS Manufacture Catalyst Equation Ethane-1,2-diol Sulfuric acid ! 2,2,4-Trimethylpentane Hydrogen fluoride (iso-octane) ! Phenol and propanone Sulfuric acid ! Bisphenol A Sulfuric acid ! source: http://www.essentialchemicalindustry.org/processes/catalysis-in-industry.html !12 HYDROFORMYLATION OF OLEFINS HOMOGENEOUS Transition Metal-Catalyzed Reaction: Linear:branched ratio Manufacture Catalyst Equation determined by: Linear aldehydes from olefins Co/Rh molecular complexes CHO - Steric hindrance (the reaction CHO + (Hydroformylation of olefins) + CO + H2 R1 R1 R1 ! linear branched is under kinetic control) Rh and Ir with promoters Acetic acid CH3OH + CO → CH3COOH Polycyclopentadiene (metathesis) WCl6/WOCl4/Et2AlCl (Metton) Active site in the MOF*: Question: Can we predict which functional H OC CO group/MOF should we have ! Rh OC PPh2 within the environment around Polypropylene Titanocenes with MAO CH2M=CH2-CHO3 → [CH2–CH2]n O M | the active site to improve linear/ O CH3 O F O O F branched ratio? We hope that *This active site has already been synthesized for topology computations will give the MIL-101(Al) answer 25 !13 Challenges in Catalysis Photocatalytic water splitting for hydrogen production CO2 reduction Selective methane activation Understand how to design catalyst structures to control catalytic activity and selectivity !14.