(153e) Supported Metal Oxides As Model Oxide Catalysts

Israel E. Wachs

OperandoMolecular Spectroscopy & Catalysis Laboratory

Department of Chemical & Biomolecular Engineering

Lehigh University, Bethlehem, PA 18015

Supported metal oxide catalysts consist of an active metal oxide surface phase dispersed on a high surface area oxide support. The molecular nature of the active surface metal oxide phase can be varied from isolated sites to oligomeric sites to nanoparticles by controlling the metal oxide surface coverage and the synthesis method. Unlike supported metal catalysts, supported metal oxide catalysts are model oxide systems that allow for determining the (1) influence of metal oxide domain size on the specific reactivity (TOF), (2) number of catalytic active sites involved in the kinetic rate-determining-step, (3) influence of oxide ligands (isolated, oligomeric or nanoparticles) on the specific reactivity, and (4) influence of adjacent secondary surface metal oxides on the molecular structure and specific reactivity of the primary surface metal oxide. The surface chemistry and kinetics of supported metal oxide catalysts will be presented to highlight the fundamental insights provided by these model oxide catalysts.