Enhanced Electrocatalytic Conversion of CO2 to C2+ Products via Intermediate Stabilized Cu+/Cu0 Interface Catalysts

Electrocatalytic reduction reaction of CO₂ (CO₂RR) into value-added multicarbon (C₂₊) products represents a sustainable strategy for mitigating greenhouse gas emissions and enhancing the production of high-value chemicals. Cu-based catalysts are optimal for the CO₂RR, facilitating the generation of C₂₊ products such as ethanol, which have significant industrial applications. However, converting CO₂ to C₂₊ products remains a great challenge, necessitating the simultaneous achievement of high current density, Faradaic efficiency (FE), and operational stability for industrial-scale implementation. Herein, we prepared Cu/Cu₂O catalysts with diverse morphologies and the ratio of the Cu⁺/Cu interface, which was rectified by regulating the interactions between the active interface and the intermediate (*CO). The electrochemical analysis demonstrated that reconstructed Cu/Cu₂O nanodendrites with dominant grain boundaries exhibited remarkable performance in generating C₂₊ products, achieving a Faradaic efficiency (FE) of 71.8%, including 49.7% FE of ethanol and a substantial partial current density of 390.0 mA cm^–2 within the flow cell. In situ spectroscopy characterization and theoretical calculations revealed that the increased ethanol selectivity originated from the rectification of the Cu/Cu₂O interface by the *CO intermediate, which accelerated H₂O dissociation, reduced the free energy for *CO hydrogenation to *COH, and facilitated asymmetric *CO-*COH coupling to preferentially reduce CO₂ to ethanol. This study provides profound insights into the C–C coupling pathways and sheds light on the rational design of ethanol-oriented electrocatalysts, contributing to sustainable chemical synthesis and energy utilization.