The Role of Phase Mixing Degree in Promoting C−C Coupling in Electrochemical CO2 Reduction Reaction on Cu‐based Catalysts

• Published in: Angewandte Chemie International Edition 2024-04, Vol.63 (16), p.e202400952-n/a
• Main Authors: Wang, Yinuo, Yang, Fei, Xu, Hongming, Jang, Juhee, Delmo, Ernest P., Qiu, Xiaoyi, Ying, Zhehan, Gao, Ping, Zhu, Shangqian, Gu, M. Danny, Shao, Minhua
• Format: Article
• Language: English
• Subjects: Absorption spectroscopy; C2+ generation; Carbon dioxide; Catalysts; Chemical reduction; CO2 reduction reaction; Controllability; Copper; Coupling; Defects; defects management; Electrochemistry; Infrared absorption; Infrared spectroscopy; infrared spectrum; Spectroscopy
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202400952

Cu‐based catalysts have been identified as the most promising candidates for generation of C2+ products in electrochemical CO2 reduction reaction. Defect engineering in catalysts is a widely employed strategy for promoting C−C coupling on Cu. However, comprehensive understanding of defect structure‐to‐activity relationship has not been obtained. In this study, controllable defects generation is achieved, which leads to a series of Cu‐based catalysts with various phase mixing degrees. It is observed that the Faradaic efficiency toward C2+ products increases with the phase mixing degree, reaching 81 % at maximum. In situ infrared absorption spectroscopy reveals that the catalysts with higher phase mixing degree tend to form *CO more easily and possess higher retention of *CO under high overpotential window, thereby promoting C−C coupling. This work sheds new light on the relationship between defects and C−C coupling, and the rational developed of more advanced Cu‐base catalysts. A comprehensive investigation on defect structure‐to‐activity relationship in electrochemical CO2 reduction reaction by mixing various phases. The efficiency of C−C coupling increased with phase mixing degree of Cu‐based catalysts, with a maximum FE of 81 % toward C2+ products. Mechanistic investigation revealed that the increased phase mixing degree facilitated *CO formation and retention at low and high overpotential, respectively.