Adjustment rules of oxides carriers on Ag SACs for ethylene epoxidation

The intrinsic properties of the support may greatly affect the geometry and electronic structure of the catalytic active site, thereby affecting the performance of the catalytic reaction. In this work, the ethylene epoxidation reaction on Ag single-atom catalysts (SACs) on supports with different reducibility (Ag₁/CeO₂(110), Ag₁/CeO₂(111), Ag₁/MgO(100), Ag₁/ZnO(100) and Ag₁/TbO₂(111)) were studied based on density functional theory (DFT) calculation. Through the microkinetic simulation of the reaction process, the activity and selectivity of the Ag SACs were analysed. Furthermore, by analysing the intrinsic properties of the SACs affecting the catalytic performance, the oxygen vacancy formation energy of oxide carriers is identified as a descriptor for reaction activity, and the difference between the length of the C–O bond in the transition states for the formation of ethylene oxide (EO) and acetaldehyde (AA) is identified as a descriptor for selectivity. This work provides the explanation on the adjustment rules of oxides carrier on the catalytic performance of Ag SACs, and provides guidance for the development of efficient SACs for ethylene epoxidation.