Fabrication of porous Au/Cu alloy catalyst for CO2 electro-reduction to CO in three-chamber electrolyzer: With Cl2 and NaOH produced as byproducts

Abstract

A three-compartment electrolyzer has been developed for the electro-reduction of CO2 to CO in an organic electrolyte, with NaOH and Cl2 produced as byproducts. In order to improve the performance of the electrolyzer, we have prepared an Au/Cu alloy electrode using a novel non-cyanide electroplating method with high porosity. By expanding the specific surface area of the cathode, and providing a large number of active sites for CO2 electro-reduction, the cathodic current density reaches to 92.7 mA·cm−2, and the Faradaic efficiency of CO formation remains stable at 94.0 %. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations analysis identified that alloying tune the electronic structure of the Au and Cu surface, resulting in promoting the activation of CO2.