Oxygen vacancies enriched Bi based catalysts for enhancing electrocatalytic CO2 reduction to formate

Abstract Electrochemical reduction of CO2 is still far away from the practical application because of the stability of CO2 and the diversity of reduction products. It is thus of great importance to further explore catalysts with high efficiency for CO2 reduction to targeting products. Herein, for the first time, a hybrid of BiOx decorated with carbon thin layer is developed as high active electrocatalyst for CO2 conversion, which is synthesized by pyrolysis using Bi MOF as precursor and sacrificial template. It is found that the as-prepared BiOx catalyst is enriched with oxygen vacancies stabilized by the decorated carbon thin layer. The oxygen vacancies enriched BiOx catalyst exhibits superior performance for CO2 reduction to formate, achieving a maximum Faradaic efficiency of 89.3% and a maximum current density of 37.8 mA cm−2. The thin carbon layer and oxygen vacancies improve the charge transfer of the catalyst and hence in favor of the high formate current density. The defects of oxygen vacancies play a vital role in CO2 adsorption and activation and thereby further enhancing the electrocatalytic ability for formate production.