Efficient CO2 electroreduction to ethanol enabled by tip-curvature-induced local electric fields

• Published in: Nanoscale 2024-07, Vol.16 (27), p.13011-13018
• Main Authors: Zhou, Jing, Liang, Qianyue, Huang, Pu, Xu, Jing, Niu, Tengfei, Wang, Yao, Dong, Yuming, Zhang, Jiawei
• Format: Article
• Language: English
• Subjects: Alcohols; Bonding strength; Carbon dioxide; Catalysts; Chemical reduction; Curvature; Efficiency; Electric fields; Electrowinning; Ethanol; Hydrogen bonding; Raman spectroscopy; Reaction kinetics
• ISSN: 2040-3364; 2040-3372; 2040-3372
• DOI: 10.1039/d4nr01173b

Electrocatalytic reduction of CO2 into multicarbon (C2+) products offers a promising pathway for CO2 utilization. However, achieving high selectivity towards multicarbon alcohols, such as ethanol, remains a challenge. In this work, we present a novel CuO nanoflower catalyst with engineered tip curvature, achieving remarkable selectivity and efficiency in the electroreduction of CO2 to ethanol. This catalyst exhibits an ethanol faradaic efficiency (FEethanol) of 47% and a formation rate of 320 μmol h−1 cm−2, with an overall C2+ product faradaic efficiency (FEC2+) reaching ∼77.8%. We attribute this performance to the catalyst's sharp tip, which generates a strong local electric field, thereby accelerating CO2 activation and facilitating C–C coupling for deep CO2 reduction. In situ Raman spectroscopy reveals an increased *OH coverage under operating conditions, where the enhanced *OH adsorption facilitates the stabilization of *CHCOH intermediates through hydrogen bonding interaction, thus improving ethanol selectivity. Our findings demonstrate the pivotal role of local electric fields in altering reaction kinetics for CO2 electroreduction, presenting a new avenue for catalyst design aiming at converting CO2 to ethanol.