UC Davis

Zeolites are nanoporous, aluminosilicate materials commonly used as catalysts in the chemical industry. The addition of metal atoms gives zeolites a wide range of catalytic activities while synthesis conditions can control the hydrophobicity, size, and shape of the pores. To aid computational studies of zeolites, we developed software to streamline the preparation of atomic structures for simulations. In conjunction with density functional theory calculations, these capabilities are employed to study Sn/Ti catalysts on silica for the Henry reaction. Next, I study Lewis-acidic tin zeolites of interest for biomass conversion and pharmaceutical production. The tin atom can be found in closed, hydrolyzed open, and open defect configurations, each with distinct catalytic properties. Computational studies of Sn-BEA for the epichlorohydrin ring opening reaction demonstrate the effect of active site speciation on turnover frequency. Active site characterization is challenging in tin zeolites, which limits our understanding of their catalytic properties and makes it difficult to improve synthetic techniques. To address this, we use high-throughput DFT calculations and experiments to validate TMPO as a 31P NMR probe that can distinguish open defect and closed sites in BEA. We use a similar approach to study acetonitrile 15N NMR probes, which can distinguish closed, hydrolyzed open, and open defect sites in Chabazite. These new techniques will improve zeolite characterization and accelerate catalyst development.