Copper as an Electron Hunter for Enhancing Bi2O2CO3 Electrocatalytic CO2 Conversion to Formate

Cu‐doped Bi2O2CO3 catalyst with copper (Cu) acting an electron hunter for conversion of carbon dioxide into formate is developed. The Cu‐Bi2O2CO3 catalyst with hollow microsphere structure extends the duration of CO2 retention on the catalyst, providing a greater number of active sites. It exhibits remarkable performance with conversion efficacy of 98.5% and current density of 800 mA cm−2 across a wide potential window (−0.8 to −1.3 V vs RHE). Density functional theory investigations reveal that the presence of copper (Cu) significantly enhances the charge density at the active sites and influences the local electronic structure of bismuth (Bi), thereby reducing the energy barrier associated with the transformation of *OCHO species into formate. Copper, as an electron hunter, can regulate the local electronic structure of Bi2O2CO3 and adsorb OCHO* key intermediates during the electrocatalytic CO2 reduction process. It is greatly improving the formate selectivity of Bi‐based catalysts, this unique structural design is expected to provide new understanding and help for the development of Bi‐based catalysts.