Epoxidation of O2 and C3h6 on M1/Pta Single-Atom Catalyst: Theory and Calculation Simulations

Abstract

Density functional theory (DFT) computational studies of a series of single-atom catalysts (SACs) Geometry of M1/PTA (M1 = Mn, Fe, Co, Ru, Rh, Pd, Os, Ir, Pt; phosphor tungstic acid (PTA) = [PW12O40 ]3− ), different spin multi-gravity, adsorption site screening, metal–support interactions and M1/PTA SACs catalyzed catalytic cycle for O2 and olefin oxidation. Studies have shown that the most likely anchoring sites for isolated single atoms on M1/PTA SACs are the 4-fold hollow sites. The molecular orbitals of the PTA-Os bonds exhibit non-bonding properties. Greatly preserved the catalytic activity of M1/PTA. Os/PTA and Ru/PTA SACs have better activation ability for oxygen molecules, because the catalysts produce dissociative adsorption of O2 , which greatly weakens the bond energy of the O-O bond. Finally, the mechanism of Os/PTA SACs catalyzing the epoxidation of O2 and propylene is proposed, and  the rate determination step (RDS) was 24.48 kcal·mol-1 for the reaction.

Keywords: Singlet-Atom Catalyst, phosphor tungstic acid, Density Functional Theory, Epoxidation