Catalysis is central to the production of chemicals and fuels, and advances in catalysis are needed to address many problems we face in energy and the environment. Experimental measurements probing the surface science of catalysis and atomic level characterization of new materials for catalysis play a key role in catalyst development. Research in our group addresses problems in both metal and oxide catalysts.
Structure and Chemistry of Alloy and Oxide Films at Bimetallic Pt Surfaces
Nearly all metal-based heterogeneous catalysts are bimetallic or multimetallic systems. Advances in predicting the properties and tailoring the structures of bimetallic interfaces are needed in order to speed progress in developing new catalysts with higher selectivity and designing nanoscale materials with improved functionality. Theoretical advances have been great over the past few years, providing much needed guidance, but the chemistry and stability of metastable phases and nanostructures that are formed at such interfaces is often exquisitely sensitive to small changes in composition or structure and so often defies prediction. We now have the tools available to provide additional information on correlations between the structure and reactivity of bimetallic interfaces, which is needed to advance the field.
Heterogeneous Catalysts for Olefin Metathesis
Propylene (C3=) is the second largest feedstock for the petrochemical industry and a shortage is developing that will increase over the next decade. To meet this demand, industry is turning to heterogeneous olefin metathesis catalysis via C2= + C4= → 2C3=. A key challenge is to improve performance of catalysts for this reaction. Unlike the well-defined, single-site homogeneous olefin metathesis catalysts, lack of fundamental information about the active sites on commercial heterogeneous olefin metathesis catalysts based on supported metal oxides (Re2O7, MoO3 and WO3) has hindered further development. We will address this obstacle by investigating designed surface oxide species on planar single-crystal oxide supports to elucidate molecular/electronic-catalytic activity/selectivity relationships.