Abstract
Ni single-atom catalysts(SACs)can perform with the extremely high activity in the activation of the C-H bond,however,deactivation caused by carbon deposition became the main obstacle for commercialization.Herein,Ni/CeO2 SAC was synthesized and employed in dry reforming of methane(DRM)reaction.The oxygen vacancies(OV)with different concentrations were successfully regulated on CeO2 surface by the replacement of Ce~(4+)cation by a smaller-size cation M(M= Mg,Co,Zn).The catalyst with the highest Oy concentration has performed with the highest activity retention and a high turnover frequency of methane(14.5 s~(-1)).During the DRM process,along with the increase of the Oy concentration from 21.9% to 30.8%,the amount of carbon deposition decreased by 50%.The effective C-H activation function from Ni SACs and CO2 activation function from Oy were synergistically combined,leading to a high activity of methane conversion and an effective carbon removal process in the OV-SAC catalytic system.This work provides a novel strategy to obtain a robust Oy-SAC catalytic system for efficient and stable C-H activation.
NSTL