Bimetallic oxide electrocatalyst with interfacial structure for enhanced electrocatalytic CO2 reduction

Abstract

The development of electrochemical carbon dioxide reduction reaction (eCO2RR) electrocatalysts with high selectivity, high activity, low cost and high enrichment is an important research direction. We report a bimetallic oxide (CuO-Sb2O3) nanocomposite catalyst with interfacial structure formed by modifying CuO with Sb2O3 to enhance CO2 reduction. The CO faraday efficiency (FE) of CuO-Sb2O3 reaches 96.2 % in a CO2-saturated KHCO3 electrolyte at −1.05 V vs. RHE, which is better than that of pure CuO (28.2 %) and pure Sb2O3 (0 %, hydrogen only). In addition, CuO-Sb2O3 with an interfacial structure presents good stability. The increased activity of eCO2RR in producing CO is due to the unique surface and interfacial structure to capture CO2, and interfacial distortions and oxygen vacancies in its internal CuO and Sb2O3, which can provide more active centers and larger electrochemical active surface area (ECSA) to provide electron transfer and promote the formation of CO products. Besides, the interfacial effect for strong adsorption of *COOH and desorption of *CO improves the selectivity of CO.