用于乙烯环氧化反应的CuCs掺杂银基催化剂设计

最近的理论研究筛选出CuCs掺杂Ag基催化剂是一种高效的乙烯环氧化催化剂ACS Catal. 11，3371 (2021)]. 然而，该工作是基于研究表面建模预测Ag基催化剂的性能，在实际反应过程中，Ag基催化剂是颗粒状的. 本文结合密度函数理论、Wulff构造理论和微观动力学分析来研究Ag基催化剂在颗粒模型上的催化性能. 研究表明，CuCs掺杂Ag基催化剂在选择性和活性方面都优于纯Ag基催化剂，这一点通过实验得到了证明. 进一步地表征分析发现，CuCs掺杂能促进颗粒的生长以及颗粒的分散，从而形成富含晶界的Ag颗粒. 此外，CuCs促进了催化剂表面亲电氧的形成，这均有利于环氧乙烷的形成和解吸. 本工作为理论与实验相结合的催化剂设计提供了一个案例研究.

Design of CuCs-doped Ag-based Catalyst for Ethylene Epoxidation

Our recent theoretical studies have screened out CuCs-doped Ag-based promising catalysts for ethylene epoxidation ACS Catal. 11, 3371 (2021)]. 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 micro kinetic 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, which is further proved by experimental validation. The characterization analysis finds that both Cu and Cs dopant promote particle growth as well as particle dispersion, resulting in a grain boundary-rich Ag particle. Besides, CuCs also facilitate electrophilic atomic oxygen formation on catalyst surface, which is benefitial for ethylene oxide formation and desorption. Our work provides a case study for catalyst design by combining theory and experiment.