Construction of Low‐Coordination Cu−C2 Single‐Atoms Electrocatalyst Facilitating the Efficient Electrochemical CO2 Reduction to Methane

Abstract

AbstractConstructing Cu single‐atoms (SAs) catalysts is considered as one of the most effective strategies to enhance the performance of electrochemical reduction of CO2 (e‐CO2RR) towards CH4, however there are challenges with activity, selectivity, and a cumbersome fabrication process. Herein, by virtue of the meta‐position structure of alkynyl in 1,3,5‐triethynylbenzene and the interaction between Cu and −C≡C−, a Cu SAs electrocatalyst (Cu−SAs/HGDY), containing low‐coordination Cu−C2 active sites, was synthesized through a simple and efficient one‐step method. Notably, this represents the first achievement of preparing Cu SAs catalysts with Cu−C2 coordination structure, which exhibited high CO2‐to‐CH4 selectivity (72.1 %) with a high CH4 partial current density of 230.7 mA cm−2, and a turnover frequency as high as 2756 h−1, dramatically outperforming currently reported catalysts. Comprehensive experiments and calculations verified the low‐coordination Cu−C2 structure not only endowed the Cu SAs center more positive electricity but also promoted the formation of H•, which contributed to the outstanding e‐CO2RR to CH4 electrocatalytic performance of Cu−SAs/HGDY. Our work provides a novel H⋅‐transferring mechanism for e‐CO2RR to CH4 and offers a protocol for the preparation of two‐coordinated Cu SAs catalysts.