Promoting Water Activation via Molecular Engineering Enables Efficient Asymmetric C–C Coupling during CO<sub>2</sub> Electroreduction
Zi‐Yu Du, Si-Bo Li, Ge-Hao Liang, Yimeng Xie, A Yao‐Lin, Yi Zhang, Hua Zhang, Jing‐Hua Tian, Shisheng Zheng, Qing‐Na Zheng, Zhou Chen, Weng Fai Ip, Jinxuan Liu, Jian‐Feng Li
Abstract
Water activation plays a crucial role in CO 2 reduction, but improving the electrocatalytic performance through controlled water activation presents a significant challenge. Herein, we achieved electrochemical CO 2 reduction to ethene and ethanol with high selectivity by promoting water dissociation and asymmetric C–C coupling by engineering Cu surfaces with N–H-rich molecules. Direct spectroscopic evidence, coupled with density functional theory calculations, demonstrates that the N–H-rich molecules accelerate interfacial water dissociation via hydrogen-bond interactions, and the generated hydrogen species facilitate the conversion of *CO to *CHO. This enables the efficient asymmetric *CHO–*CO coupling to C 2 products with a faradaic efficiency (FE) ∼ 30% higher than that of the unmodified catalyst. Moreover, by adjustment of the relative *CHO/*CO coverage via Cu surface facet regulation, the selectivity can be entirely switched between C 2 products and CH 4 . These mechanistic insights further guided the development of a more efficient catalyst by directly modifying Cu 2 O nanocubes with the N–H-rich molecule, achieving remarkable C 2 product (mainly ethene and ethanol) FEs of 85.7% at a current density of 800 mA cm –2 and excellent stability under nearing industrial conditions. This study advances our understanding of the CO 2 reduction mechanisms and offers an effective and general strategy for enhancing electrocatalytic performance by accelerating water dissociation.