Selective electrochemical reduction of CO2 to CO on CuO-derived Cu nanowires

In this work, we report a new synthesis method to prepare a Cu nanowire electrocatalyst for selective CO2 reduction at room temperature and atmospheric pressure. Cu nanowire array electrodes were prepared through a two-step synthesis of Cu(OH)2 and CuO nanowire arrays on Cu foil substrates and a subsequent electrochemical reduction of the CuO nanowire arrays. The Cu nanowire arrays are able to electrochemically reduce CO2 to CO with a faradaic efficiency of ∼50% at a moderate overpotential of 490 mV, which is significantly higher than that of polycrystalline Cu foil catalysts at identical conditions. The improved faradaic efficiency for the reduction of CO2 to CO is ascribed to the enhanced stabilization for the CO2˙(-) intermediate on the high surface area Cu nanowire arrays.