Dynamic Frustrated Lewis Pairs on Ceria for Direct Nonoxidative Coupling of Methane

Abstract

While the regulation of surface oxygen vacancy (VO) of ceria is an effective methodology to construct solid frustrated Lewis pairs (FLPs), the intrinsic properties and potential applications of solid FLPs are not well-demonstrated. Herein, we present a theoretical study on the formation rules and dynamic behaviors of FLPs on CeO2(110) and their performance on nonoxidative conversion of methane. The density functional theory studies show that the formation of solid FLPs on CeO2(110) is dependent on the number of oxygen vacancies (VOs). The FLPs constructed by three or more VOs are stable in thermodynamics, whereas the FLPs containing few VOs (i.e., VO monomer and VO dimer) are less stable but can be dynamically formed via thermal fluctuation and reactant-adsorption, as observed by ab initio molecular dynamics simulations. Hence, the general existence of FLPs on reduced CeO2(110) surface under reaction conditions is revealed. Calculations on methane activation show that FLPs are active for C–H bond breaking...