Highly Ethylene‐Selective Electrocatalytic CO<sub>2</sub> Reduction Enabled by Isolated Cu−S Motifs in Metal–Organic Framework Based Precatalysts
Chun Fang Wen, Min Zhou, Peng Fei Liu, Yuanwei Liu, Xuefeng Wu, Fangxin Mao, Sheng Dai, Beibei Xu, Xue Lu Wang, Zheng Jiang, Pan Hu, Shuang Yang, Hai Feng Wang, Hua Gui Yang
Abstract
Abstract Copper‐based materials are efficient electrocatalysts for the conversion of CO 2 to C 2+ products, and most these materials are reconstructed in situ to regenerate active species. It is a challenge to precisely design precatalysts to obtain active sites for the CO 2 reduction reaction (CO 2 RR). Herein, we develop a strategy based on local sulfur doping of a Cu‐based metal–organic framework precatalyst, in which the stable Cu−S motif is dispersed in the framework of HKUST‐1 (S‐HKUST‐1). The precatalyst exhibits a high ethylene selectivity in an H‐type cell with a maximum faradaic efficiency (FE) of 60.0 %, and delivers a current density of 400 mA cm −2 with an ethylene FE up to 57.2 % in a flow cell. Operando X‐ray absorption results demonstrate that Cu δ+ species stabilized by the Cu−S motif exist in S‐HKUST‐1 during CO 2 RR. Density functional theory calculations indicate the partially oxidized Cu δ+ at the Cu/Cu x S y interface is favorable for coupling of the *CO intermediate due to the modest distance between coupling sites and optimized adsorption energy.