Electrochemical reduction of CO₂ on core-shell Cu/Au nanostructure arrays for syngas production

Electrocatalytically converting CO₂ to hydrocarbons is a very attractive way to use the excess electricity generated from renewable energies. In this paper, we report the electrochemical reduction of CO₂ based on Cu nanowire arrays. The Cu nanostructured electrode shows much higher current density than polycrystalline Cu. By sputter coating a thin layer of Au on the Cu nanowires, the Faradaic efficiency (FE) of CO can exceed 30%. At an overpotential of 540 mV with respect to the formation of CO, the Cu/Au core-shell nanowire array electrode catalyses the formation of syngas, a very useful gas mixture, with a stable CO/H₂ ratio.