Bridging Homogeneous and Heterogeneous Catalysis: In-Situ Characterization and Theory of Supported Metal Complexes

University Of California-Davis, Davis CA

Investigators

Abstract

Catalysis plays a central role in chemical manufacturing, energy conversion, and environmental protection. A central challenge is to bridge homogeneous and heterogeneous catalysts: metal complexes on supports illustrate some of the best connections between them. However, there is a striking lack of their characterization with in situ techniques, which allow the structures of these catalysts to be investigated in their working state. The goal of this research is to develop and demonstrate methods of in situ spectroscopy and flow reactor techniques for investigation of oxide-supported transition metal complex catalysts in the presence of gas-phase reactants, such as paraffins, and olefins. The techniques include in situ IR, X-ray absorption near edge structure, and extended X-ray absorption fine structure spectroscopies. Theoretical approaches will utilize density functional theory. The catalysts will include oxide-supported Ta, Cr, and Zr complexes and a new zeolite-supported Pt complex. The combined characterization data and theory will permit determination of how the atomic-scale catalyst structure and the rates of the catalytic reactions depend on the structure and composition of the adsorbate and the support, as well as the reaction conditions. There is an excellent opportunity to identify reactive intermediates and establish reaction mechanisms. The grand challenge will be to predict catalytic activities. The research will have strong broader impacts through a mentorship program that involves students from underrepresented groups in research projects. An interdisciplinary IGERT program is in place that focuses on nanoscience and technology.