Highly selective and active Cu-In2O3/C nanocomposite for electrocatalytic reduction of CO2 to CO.

The Cu-In2O3/C nanocomposite was prepared by a simple solid-phase reduction method. The introduction of In2O3 into Cu/C to form the Cu-In2O3/C nanocomposite evidently enhances the electrocatalytic activity for the selective reduction of CO2 to CO. Specifically, the Cu-In2O3/C nanocomposite exhibits higher Faraday efficiency (FE = 86.7%) at -0.48 V vs. the reversible hydrogen electrode (RHE) in the electrocatalytic reduction of CO2 to CO and larger current densities (55 mA cm-2) under a low overpotential (-1.08 V vs. RHE). These indicate its superior performance over many of the reported Cu-based catalysts [1-4]. It was also found that by rationally adjusting the applied potential, tunable syngas can be formed, which can be used to synthesize formic acid, methyl ether, methanol, synthetic fuels, or other bulk chemicals through appropriate industrial processes. Furthermore, the Cu-In2O3/C nanocomposite maintains good stability in the electrocatalytic reduction of CO2. This work demonstrates a novel strategy to convert CO2 into desired products with high energy efficiency and large current density under low overpotential by the rational designing of non-precious metal catalysts.