Selective and Energy Efficient Electrocatalytic CO ₂ ‐to‐Ethanol Conversion through Anion Modulation

Abstract

Abstract Ethanol, with its high market value and stable global demand, stands out as an attractive product of electrocatalytic CO 2 reduction. However, achieving high ethanol selectivity and energy efficiency at industrial current densities remains challenging. In this study, we employed a blended anion modulation strategy to enhance the selectivity and energy efficiency of CO 2 ‐to‐ethanol conversion. The Cu 2 (OH) 3 F pre‐catalyst achieved Faradaic efficiencies of 50% and 93% for ethanol and C 2+ , respectively, at 700 mA cm −2 in a blended electrolyte consisting of 2 M KOH and 1 M KCl. Comprehensive electrochemical tests, combined with in situ characterizations and theoretical analysis, revealed that chloride and hydroxide increased *CO coverage for efficient C─C coupling. Moreover, hydroxide stabilizes the *CHCOH intermediate through hydrogen bonding with the adsorbed hydroxide on the catalyst surface, while Cl synergistically enhances its reactivity by promoting water dissociation toward the ethanol pathway.