Highly efficient electrochemical CO2 reduction over crystalline–amorphous In2O3–CeOx heterostructures

Abstract

The electrochemical reduction reaction of CO₂ (CO₂RR) to fuels and chemicals is a promising approach to consume greenhouse gases and mitigate the dependence on fossil fuels. Herein, we synthesized an effective crystalline–amorphous In₂O₃–CeO_x heterostructure, which exhibited high catalytic performance for CO₂-to-formate conversion. The maximum faradaic efficiency (FE) of 94.8% was achieved, and above 90% FE can be maintained in a wide potential range from −0.8 to −1.2 V vs. RHE. Detailed studies showed that In₂O₃ functioned as the active site for CO₂ activation and formate formation, and the amorphous CeO_x was beneficial for the electron transfer, leading to the electronic structure reconfiguration of In₂O₃. Hence, the In₂O₃–CeO_x heterostructure enhanced the adsorption of *OCHO intermediates and lowered the energy barrier forming *HCOOH from *OCHO.