Enhanced Electrocatalytic Reduction of CO₂ via Chemical Coupling between Indium Oxide and Reduced Graphene Oxide

Abstract

The chemical coupling interaction has been explored extensively to boost heterogeneous catalysis, but the insight into how chemical coupling interaction works on CO₂ electroreduction remains unclear. Herein we demonstrate how the chemical coupling interaction between porous In₂O₃ nanobelts and reduced graphene oxide (rGO) could substantially improve the electrocatalytic activity toward CO₂ electroreduction. Such an In₂O₃-rGO hybrid catalyst showed 1.4-fold and 3.6-fold enhancements in Faradaic efficiency and specific current density for the formation of formate at -1.2 V versus reversible hydrogen electrode relative to the catalyst prepared by physically loading of In₂O₃ nanobelts onto rGO, respectively. The density functional theory calculations and electrochemical analysis together revealed that the chemical coupling interaction boosted CO₂ electroreduction activity by improving electrical conductivity and stabilizing key intermediate HCOO^-*. The present work not only deepens an understanding of chemical coupling effect but also provides an effective lever to optimize the catalytic performance toward CO₂ electroreduction.