Co-modulating CO Adsorption and Interfacial Water Dissociation through a Lewis Acid Site Boosts Industrial CO₂-to-Ethylene Conversion

Copper-based electrocatalysts have shown great potential for electrolytic CO₂ reduction (CO₂RR) to value-added multi-carbon products but suffer from poor selectivity and activity due to the uncontrollable CO adsorption and sluggish C–C coupling kinetics. Herein, we develop a dopant-driven interfacial engineering strategy by incorporating chromium (Cr) into copper oxide, which in situ reconstructs to Cu–CrO_x heterointerfaces under CO₂RR conditions. Combined experimental and theoretical analyses reveal that Lewis acidic CrO_x clusters tailor the electronic structure of Cu sites, thereby strengthening the CO adsorption and accelerating C–C coupling. The Cu–CrO_x interface also promotes water dissociation to supply active hydrogen species for multiple hydrogenation steps. The optimized catalyst achieves a 59.2% faradaic efficiency for ethylene and maintains stable operation for over 110 h at 2.45 V in a membrane electrode assembly electrolyzer. This work highlights dopant-enabled interfacial engineering as a versatile strategy for steering CO₂RR activity and selectivity toward multi-carbon products, offering mechanistic insights that advance the field.