Carburized In₂O₃ Nanorods Endow CO₂ Electroreduction to Formate at 1 A cm^–2

Abstract

The double high index of current density and Faradaic efficiency in carbon dioxide electroreduction is a great challenge. Herein, we synthesized carburized indium oxide nanorods (In2O3-C) by pyrolysis of the metal–organic framework (MOF) precursor [MIL-68 (In)]. The electronic structure of In was regulated, and the localization of negative charges was increased on the surface of the In2O3-C catalyst, resulting in a high Faradaic efficiency of 97.2% at −1.0 V vs RHE and above 90% in a wide potential range of 500 mV. Furthermore, it reached a current density of −1.0 A·cm–2 in the flow cell for producing formate efficiently. The complete reaction path from CO2 to formate on In2O3-C was in situ investigated by attenuated total reflection surface-enhanced infrared adsorption spectroscopy and 2D/3D surface-enhanced Raman spectroscopy.