(621co) Computational Study of Catalysts and Reaction Processes for Propene Epoxidation Using Molecular Oxygen As Oxidant without Co-Reductants

Authors: 
Yang, B., New Mexico State University
Manz, T. A., New Mexico State University

Propylene oxide (PO) is a key intermediate in the chemical industry and one of the most produced chemicals worldwide by mass. All of the existing commercial methods for PO production consume H2 as a co-reactant (e.g., H2O2 and cumene processes) or produce co/by-products. Propene epoxidation utilizing O2 as oxidant without co-reactants or co-products could potentially give economic and environmental benefits. In our study, a new propene epoxidation reaction scheme and catalysts are designed to fulfill this goal. Previous research has shown the active allylic H atom in the propene molecule is the main cause of by-product formation. We discuss strategies for overcoming this limitation. We performed computational screening studies using density functional theory (DFT) calculations to identify suitable catalysts and reaction processes. Complete reaction cycles for each catalyst were computed, including ground state and transition state energies. Chemical potential diagrams were calculated that describe the relative energies of different catalyst forms as a function of the oxygen atom chemical potential. Effective activation barriers, possible side reactions, and catalyst deactivation reactions have been studied for each catalyst.