Atmosphere Induces Tunable Oxygen Vacancies to Stabilize Single‐Atom Copper in Ceria for Robust Electrocatalytic CO <sub>2</sub> Reduction to CH <sub>4</sub>
Fang Huang, Xiangyu Chen, Huanhuan Sun, Qingduo Zeng, Junjie Ma, Dong Wei, Jinliang Zhu, Zhengjun Chen, Taoyuan Liang, Xucai Yin, Xijun Liu, Feng Xu, Huibing He
Abstract
Abstract Electrochemical carbon dioxide reduction (ECO 2 RR) shows great potential to create high‐value carbon‐based chemicals, while designing advanced catalysts at the atomic level remains challenging. The ECO 2 RR performance is largely dependent on the catalyst microelectronic structure that can be effectively modulated through surface defect engineering. Here, we provide an atmosphere‐assisted low‐temperature calcination strategy to prepare a series of single‐atomic Cu/ceria catalysts with varied oxygen vacancy concentrations for robust electrolytic reduction of CO 2 to methane. The obtained Cu/ceria catalyst under H 2 environment (Cu/ceria‐H 2 ) exhibits a methane Faraday efficiency (FE CH4 ) of 70.03 % with a turnover frequency (TOF CH4 ) of 9946.7 h −1 at an industrial‐scale current density of 150 mA cm −2 in a flow cell. Detailed studies indicate the copious oxygen vacancies in the Cu/ceria‐H 2 are conducive to regulating the surface microelectronic structure with stabilized Cu + active center. Furthermore, density functional theory calculations and operando ATR‐SEIRAS demonstrate that the Cu/ceria‐H 2 can markedly enhance the activation of CO 2 , facilitate the adsorption of pivotal intermediates *COOH and *CO, thus ultimately enabling the high selectivity for CH 4 production. This study presents deep insights into designing effective electrocatalysts for CO 2 to CH 4 conversion by controlling the surface microstructure via the reaction atmosphere.