摘要

Atomically dispersed supported catalysts show superior catalytic activity and selectivity in diverse reactions, while the challenging part is identifying the active sites and revealing the reaction mechanisms, which play essential roles in rational design of efficient catalysts to massive energy consumption reduction. Herein, an atom vacancy interface (AVI) model is proposed, for the first time, based on a case study of atomically dispersed Co atoms distributed on 2H-MoS2 surfaces as promising catalysts for hydrodeoxygenation (HDO) reactions. The results show that the reactive single Co atom promotes the H-2 activation and leads to largely increased sulfur vacancies adjacent to the metals and the formation of metal vacancy interfaces on the MoS2 surface. Detailed reaction mechanism studies demonstrate that the AVI model is quite different from edge vacancy dominated unprompted MoS2 and traditionally prepared CoMoS2 catalysts. The novel structure results in a considerable reduction of energy barriers of three elementary steps including C-O scission, hydrogenation processes, and catalytic center regeneration, and eventually boots the HDO reaction at low temperature.