Design of CuCs-doped Ag-based catalyst for ethylene epoxidation

Abstract

Our recent theoretical studies have screened out CuCs-doped Ag-based as promising catalysts for ethylene epoxidation (ACS Catalysis, 2021, 3371-3383). The theoretical results were based on surface modeling, while in the actual reaction process Ag catalysts are particle shaped. In this work, we combine Density functional theory (DFT), Wulff construction theory, and microkinetic analysis to study the catalytic performance of Ag catalysts at the particle model. It demonstrates that the CuCs-doped Ag catalysts are superior to pure Ag catalysts in terms of selectivity and activity in ethylene oxide production, which is further proved by our experimental results. The characterization analysis finds that both Cu and Cs dopants promote particle growth as well as particle dispersion, resulting in a grain boundary-rich Ag particle. Besides, CuCs also facilitates electrophilic atomic oxygen formation on catalyst surface, which is benefit for ethylene oxide formation and desorption. Our work provides a case study of Ag-based catalyst design for ethylene epoxidation by combining theory and experiment.