Sn-Doped CuOx with engineered electronic structure for efficient CO2 electroreduction to CO

Cu-based catalysts have attracted considerable attention for electrocatalytic reduction of CO2 owing to their potential to produce value-added products. However, achieving high selectivity toward specific products and long-term stability at high current densities still remains challenging over Cu-based catalysts. Herein, highly selective and durable Sn-doped CuOx catalysts (R-SnCuOx) were synthesized via distributed preparation and in situ reconstruction for reduction of CO2 to CO. At cathodic reduction potentials, Sn doping stabilizes the Cu(I) active center through electronic regulation, thereby enhancing the reduction resistance of R-SnCuOx. R-SnCuOx with optimized Sn loading of 7.2 wt.% achieved a maximum CO Faradaic efficiency around 97.5%and a CO partial current density of 296 mA cm-2 in a membrane electrode assembly. Furthermore, it still maintained over 90% CO selectivity after 16 h at 150 mA cm−2. Mechanistic studies indicate that incorporation of Sn modulates the surface electronic configuration of Cu2O, concomitantly lowering the rate-determining step activation energy barrier and intensifying the CO-generation kinetics in CO2 electroreduction. Meanwhile, techno-economic assessment studies on the economic feasibility of the reduction of CO2 to CO indicate that industrial-scale production is achievable by optimizing carbon single-pass conversion and current density. This study provides valuable insights for realizing the industrial application of electrocatalytic CO2 reduction to CO.