A High-Performance Cu–Zn Alloy Electrode for CO ₂ Conversion to CO in an Organic Electrolyte in a Three-Membrane Electrolyzer with Na ₂ CO ₃ /Cl ₂ Cogenerated Simultaneously

A three-membrane electrolyzer has been constructed for CO2 electroreduction to CO in an organic electrolyte, with Na2CO3 and Cl2 cogenerated. In order to improve the CO2 conversion efficiency, a porous Cu–Zn alloy electrode has been prepared by coelectrodeposition of Zn and Cu on copper foam. When the Zn content reaches 35.2%, the Cu–Zn alloy exhibits high performance. At the applied potential of −1.8 V (vs SHE), the current density reaches to 116.6 mA cm–2, with the Faradaic efficiency of CO formation stabilized at 94.2% for 50 h. Density functional theory calculations reveal that the formation of the Cu–Zn alloy modulates the electronic structures of Cu and Zn atoms, leading to shifts in their d-band centers. This electronic adjustment adjusts the adsorption energy of CO2 and the desorption energy of *CO on the electrode surface, thereby enhancing the activity and selectivity of the electrochemical reduction of CO2 to CO.