In situ construction of a built-in electric field for efficient CO2 electroreduction†

Studying the structural evolution process of Cu-based heterogeneous catalysts is of great significance for converting CO₂ into valuable chemicals. In this study, we suggest an efficient synthesis method for Cu-based catalysts that facilitate the formation of heterojunctions with In₂O₃, providing a mild and effective route for CO₂ and H₂O reduction. The resulting syngas ratios (CO/H₂) are maintained within a narrow range of 0.6 to 1.5 across a broad potential window. Experiments and theoretical calculations demonstrate that the in situ reconstructed internal electric field significantly lowers the energy barrier for CO₂ reduction, favoring the formation of *CO intermediates while concurrently suppressing the hydrogen evolution reaction (HER) during the electrochemical CO₂ reduction process.