Zhang, Hui; Lou, Shanshan; Yang, Fan; Fan, Keyi; Gu, Zhengxin; Li, Wangbo; Chen, Yihe; Gan, Yizhen; Ma, Lushan; Wang, Guoliang; Yang, Hui

CHEMICAL ENGINEERING JOURNAL

2025, ,

Zhang, Hui; Lou, Shanshan; Yang, Fan; Fan, Keyi; Gu, Zhengxin; Li, Wangbo; Chen, Yihe; Gan, Yizhen; Ma, Lushan; Wang, Guoliang; Yang, Hui

The electrochemical CO2 reduction reaction (CO2RR) in acidic electrolytes can achieve higher carbon utilization efficiency. However, challenges remain, such as the competitive hydrogen evolution reaction (HER), structural instability of the catalysts, particularly copper-based catalysts designed for multi-carbon (C2+) products. In this study, we designed an imidazolium salt-functionalized Cu2O@SiO2 catalyst which simultaneously enhanced CO2 capture and selective CO2RR to C2+ products in an acidic electrolyte. In-situ and quasi-in-situ characterizations demonstrate that this strategy not only stabilizes the metastable Cu+ species but also enhances CO2 and *CO adsorption and promotes the critical *CO-*COH coupling essential for C2+ generation, with mechanistic insights corroborated by theoretical calculations. The optimized catalyst achieves a remarkable Faradaic efficiency of 71.54 % (+/- 3.85 %) for C2+ products at 400 mA cm-2, displaying a 2.1-fold enhancement over pristine Cu2O (33.84 %), along with effective suppression of the HER. A single-pass carbon efficiency of 32.43 % was obtained in a pH = 2 electrolyte with the operational stability. This dual-functional catalyst architecture combining imidazolium salts modification with protective nano-shell engineering provides a promising strategy for advancing acidic CO2RR systems toward practical applications.