Decrypting the Controlled Product Selectivity over Ag−Cu Bimetallic Surface Alloys for Electrochemical CO<sub>2</sub> Reduction
Daixing Wei, Yiqing Wang, Chung‐Li Dong, Zhengqi Zhang, Xinyu Wang, Yucheng Huang, Yuchuan Shi, Xiaoli Zhao, Jialin Wang, Ran Long, Yujie Xiong, Fan Dong, Mingtao Li, Shaohua Shen
Abstract
Abstract Electrochemical CO 2 reduction reaction (ECO 2 RR) with controlled product selectivity is realized on Ag−Cu bimetallic surface alloys, with high selectivity towards C2 hydrocarbons/alcohols (≈60 % faradaic efficiency, FE), C1 hydrocarbons/alcohols (≈41 % FE) and CO (≈74 % FE) achieved by tuning surface compositions and applied potentials. In situ spectral investigations and theoretical calculations reveal that surface‐composition‐dependent d‐band center could tune *CO binding strengths, regulating the *CO subsequent reaction pathways and then the product selectivity. Further adjusting the applied potentials will alter the energy of participated electrons, which leads to controlled ECO 2 RR selectivity towards desired products. A predominant region map, with an indicator proposed to evaluate the thermodynamic predominance of the *CO subsequent reactions, is then provided as a reliable theoretical guidance for the controllable ECO 2 RR product selectivity over bimetallic alloys.