Cu-based catalysts are boosting electrocatalysts in CO₂ reduction reactions to high-value multicarbon (C₂₊) products. Because of the unstable Cu⁺ species and the unclear microscopic structure in reactions, Cu-based catalysts still face significant challenges of low selectivity and poor durability at high current density. Herein, we report a thermodynamically driven comproportionation strategy for forming a Cu⁰/Cu⁺/Cu⁰ interface to stabilize Cu⁺ species. When tested in a flow cell containing neutral electrolyte, the sample showed a high C₂₊ products Faradaic efficiency (FE_C2+) of 92.3% at a partial current density of 276.9 mA cm⁻². In a membrane electrode assembly, the sample achieved a 90.1% FE_C2+ and maintained continuous operation for over 50 h at industrial current density. Further investigation demonstrates outstanding FE_C2+ of >80% at a large industrial current of 10 A. Mechanism studies reveal that the Cu⁰/Cu⁺/Cu⁰ interface lowers the energy barrier for C–C coupling in the reaction, thus facilitating the conversion of CO₂ to C₂₊ products.

铜基催化剂正在推动电催化剂在 CO ₂还原反应中生成高价值的多碳 (C ₂₊ ) 产品。由于Cu ⁺物种不稳定和反应中微观结构不明确，铜基催化剂仍然面临选择性低和高电流密度下耐久性差的重大挑战。在此，我们报告了一种热力学驱动的复合策略，用于形成 Cu ⁰ /Cu ⁺ /Cu ⁰界面以稳定 Cu ⁺物质。当在含有中性电解质的流通池中进行测试时，样品在276.9 mA cm ^-2的部分电流密度下表现出92.3%的高C ₂₊产物法拉第效率（FE _C2+ ） 。在膜电极组件中，样品实现了 90.1% FE _C2+，并在工业电流密度下连续运行超过 50 小时。进一步的研究表明，在 10 A 的大工业电流下，FE _{C2+出色，>80%。机理研究表明，Cu} ⁰ /Cu ⁺ /Cu ⁰界面降低了反应中 C-C 耦合的能垒，从而促进了转化CO ₂转化为C ₂₊产物。