Enhanced Electrocatalytic Conversion of CO 2 to C 2+ Products via Intermediate Stabilized Cu + /Cu 0 Interface Catalysts

Electrocatalytic reduction reaction of CO 2 (CO 2 RR) into value-added multicarbon (C 2+ ) 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 CO 2 RR, facilitating the generation of C 2+ products such as ethanol, which have significant industrial applications. However, converting CO 2 to C 2+ 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/Cu 2 O 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/Cu 2 O nanodendrites with dominant grain boundaries exhibited remarkable performance in generating C 2+ 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/Cu 2 O interface by the *CO intermediate, which accelerated H 2 O dissociation, reduced the free energy for *CO hydrogenation to *COH, and facilitated asymmetric *CO-*COH coupling to preferentially reduce CO 2 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.