Bimetallic In₂O₃/Bi₂O₃ Catalysts Enable Highly Selective CO₂ Electroreduction to Formate within Ultra-Broad Potential Windows

CO2 electrochemical reduction reaction (CO2RR) to formate is a hopeful pathway for reducing CO2 and producing high-value chemicals, which needs highly selective catalysts with ultra-broad potential windows to meet the industrial demands. Herein, the nanorod-like bimetallic In2O3/Bi2O3 catalysts were successfully synthesized by pyrolysis of bimetallic InBi-MOF precursors. The abundant oxygen vacancies generated from the lattice mismatch of Bi2O3 and In2O3 reduced the activation energy of CO2 to *CO2 center dot-$$ {}<^>{\ast }{\mathrm{CO}}_2{\cdotp}<^>{-} $$ and improved the selectivity of *CO2 center dot-$$ {}<^>{\ast }{\mathrm{CO}}_2{\cdotp}<^>{-} $$ to formate simultaneously. Meanwhile, the carbon skeleton derived from the pyrolysis of organic framework of InBi-MOF provided a conductive network to accelerate the electrons transmission. The catalyst exhibited an ultra-broad applied potential window of 1200 mV (from -0.4 to -1.6 V vs RHE), relativistic high Faradaic efficiency of formate (99.92%) and satisfactory stability after 30 h. The in situ FT-IR experiment and DFT calculation verified that the abundant oxygen vacancies on the surface of catalysts can easily absorb CO2 molecules, and oxygen vacancy path is dominant pathway. This work provides a convenient method to construct high-performance bimetallic catalysts for the industrial application of CO2RR.