Ampere-Level CO<sub>2</sub>-to-Ethanol Conversion via Boron-Incorporated Copper Electrodes
Gangfeng Wu, Chang Zhu, Jianing Mao, Guihua Li, Shoujie Li, Xiao Dong, Aohui Chen, Yanfang Song, Guanghui Feng, Xiaohu Liu, Yiheng Wei, Jiangjiang Wang, Wei Wei, Wei Chen
Abstract
Partial positive valence Cu (Cu δ+ ) sites on Cu-based electrocatalysts are important for C–C coupling to form C 2+ products; however, maintaining the stability of Cu δ+ remains a challenge. Herein, an ultrastable Cu δ+ (0 < δ < 1) site over the copper penetration electrode was constructed using boron to tailor the *CO adsorption strength and configuration for facilitating C–C coupling, which achieves a C 2+ Faradaic efficiency (FE) of 78.9% at −0.91 V (vs reversible hydrogen electrode), of which the ethanol FE reaches 52.4% with an ultrahigh partial current density of 1.25 A cm –2, far outperforming state-of-the-art electrocatalysts, corresponding to the ethanol cathodic energy efficiency (CEE) of 27.7%. Spectroscopy and computation results show that introducing boron to optimize the coordination numbers and oxidation states of surface Cu atoms enables enrichment of locally asymmetric *CO atop and *CHO intermediates to trigger asymmetric C–C coupling to form ethanol.