Optimizing C─C Coupling on Cu <sup>0</sup> /Cu <sup>+</sup> /Ga Interfaces by Enhancing Active Hydrogen Absorption for Excellent CO <sub>2</sub> ‐to‐C <sub>2+</sub> Electrosynthesis
Xiaoning Qi, Yikai Yang, Y. C. Lan, Xiuming Bu, Siwei Yang, Di Yin, Hongwen Huang, Johnny C. Ho, Xianying Wang
Abstract
Abstract The electrocatalytic reduction of CO 2 (CO 2 RR) to high‐value chemicals and fuels offers a promising route for a clean carbon cycle. However, it often suffers from low catalytic activity and poor selectivity. Heterostructure construction has been shown to be an effective strategy for producing multi‐carbon products, but the synergistic mechanisms between multiple active sites resulting from the reconstruction process remain unclear. In this study, a Ga 2 O 3 /CuO heterostructure is established via a simple sol–gel method to produce C 2+ products. Experimental results demonstrate that Ga 2 O 3 stabilizes Cu + to form Cu 0 /Cu + /Ga active centers and enhances water‐splitting ability during the reaction. The improved hydrogen absorption on the Ga site shifts the C─C coupling reaction pathway from * OCCO to the asymmetric * OCCHO coupling path with a lower energy barrier. As a result, the catalysts exhibit superior CO 2 RR performance, achieving a 70.1% C 2+ Faradaic efficiency at −1.2 V RHE in a flow cell, with ethylene Faradaic efficiency reaching 58.3% and remaining stable for 10 h.