Reducing CO2 into value-added chemicals and fuels by electrochemical reduction of CO2 (CO2ER) in an aqueous medium is considered a potential way to store intermittent renewable energy and alleviate the energy crisis. Cu-based catalysts are a common electrocatalyst used in CO2ER. However, selectivity has always been a difficult problem to solve, especially in terms of the production of C1 products. Based on the characteristics of the carbon framework and the CoP2O6 species, herein, Cu and CoP2O6 co-anchored N-doped hollow carbon spheres (CoP2O6/HCS-Cu) with a precisely controllable copper content were prepared, in order to produce formate with a high current density and Faraday efficiency from CO2ER. The ratio of copper to cobalt has a strong influence on the catalytic performance of the catalyst. In addition, the experimental results and density functional theory calculations show that CoP2O6 is an important factor in promoting the formation of formate.
Keywords: CoP2O6; copper/carbon catalysts; electrochemical reduction of CO2; formate; hollow carbon spheres.