Li, Shoujie; Dong, Xiao; Wu, Gangfeng; Song, Yanfang; Mao, Jianing; Chen, Aohui; Zhu, Chang; Li, Guihua; Wei, Yiheng; Liu, Xiaohu; Wang, Jiangjiang; Chen, Wei; Wei, Wei

NATURE COMMUNICATIONS

2024, 15, 2041-1723

Li, Shoujie; Dong, Xiao; Wu, Gangfeng; Song, Yanfang; Mao, Jianing; Chen, Aohui; Zhu, Chang; Li, Guihua; Wei, Yiheng; Liu, Xiaohu; Wang, Jiangjiang; Chen, Wei; Wei, Wei

Synthesis of valuable chemicals from CO2 electroreduction in acidic media is highly desirable to overcome carbonation. However, suppressing the hydrogen evolution reaction in such proton-rich environments remains a considerable challenge. The current study demonstrates the use of a hollow fiber silver penetration electrode with hierarchical micro/nanostructures to enable CO2 reduction to CO in strong acids via balanced coordination of CO2 and K+/H+ supplies. Correspondingly, a CO faradaic efficiency of 95% is achieved at a partial current density as high as 4.3 A/cm(2) in a pH = 1 solution of H2SO4 and KCl, sustaining 200 h of continuous electrolysis at a current density of 2 A/cm(2) with over 85% single-pass conversion of CO2. The experimental results and density functional theory calculations suggest that the controllable CO2 feeding induced by the hollow fiber penetration configuration primarily coordinate the CO2/H+ balance on Ag active sites in strong acids, favoring CO2 activation and key intermediate *COOH formation, resulting in enhanced CO formation.