CO2-assisted formation of grain boundaries for efficient CO–CO coupling on a derived Cu catalyst

• Published in: National Science Open Vol. 2; no. 2
• Main Authors: Zhuang-Zhuang Niu, Li-Ping, Chi, Zhi-Zheng, Wu, Peng-Peng, Yang, Ming-Hui, Fan, Min-Rui Gao
• Format: Journal Article
• Language: English
• Published: Beijing EDP Sciences 01.03.2023; Science Press
• Subjects: defective sites; electrochemical CO2 reduction; Electrodes; Electrolytes; Energy; Grain boundaries; Morphology; multicarbon products; Nitrates; perovskite oxide; Scanning electron microscopy; Spectrum analysis; structural evolution; Transmission electron microscopy
• ISSN: 2097-1168; 2097-1400
• DOI: 10.1360/nso/20220044

The electrochemical CO2 reduction reaction (CO2RR) on Cu catalyst holds great promise for converting CO2 into valuable multicarbon (C2+) compounds, but still suffers poor selectivity due to the sluggish kinetics of forming carbon–carbon (C–C) bonds. Here we reported a perovskite oxide-derived Cu catalyst with abundant grain boundaries for efficient C–C coupling. These grain boundaries are readily created from the structural reconstruction induced by CO2-assisted La leaching. Using this defective catalyst, we achieved a maximum C2+ Faradaic efficiency of 80.3% with partial current density over 400 mA cm−2 in neutral electrolyte in a flow-cell electrolyzer. By combining the structural and spectroscopic investigations, we uncovered that the in-situ generated defective sites trapped by grain boundaries enable favorable CO adsorption and thus promote C–C coupling kinetics for C2+ products formation. This work showcases the great potential of perovskite materials for efficient production of valuable multicarbon compounds via CO2RR electrochemistry.