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

Electrocatalytic reduction of CO into multicarbon (C) products offers a promising pathway for CO 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 CO to ethanol. This catalyst exhibits an ethanol faradaic efficiency (FE) of 47% and a formation rate of 320 μmol h cm, with an overall C product faradaic efficiency (FE) reaching ∼77.8%. We attribute this performance to the catalyst's sharp tip, which generates a strong local electric field, thereby accelerating CO activation and facilitating C-C coupling for deep CO reduction. 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 CO electroreduction, presenting a new avenue for catalyst design aiming at converting CO to ethanol.