Electrochemical reduction of CO2 in water-acetonitrile mixtures on nanostructured Cu electrode

• Nanostructured Cu electrodes show well-defined electrochemical signals in acetonitrile.
• High CO2 reduction currents are obtained in H2O/CH3CN mixture of 0.25 water molar fraction.
• Nanostructured Cu electrode is a better electrocatalyst for CO2 reduction than Cu or Au electrodes.

This communication studies the CO2 reduction reaction in H2O/CH3CN mixtures on nanostructured copper. It was found that the nanostructured copper electrode presents a well-defined voltammogram in acetonitrile, where it can be seen three signals related to adsorbed or surface attached (thin films) species. Also, it was found that the current density of CO2 reduction in mixtures H2O/CH3CN on nanostructured copper electrodes with a mole fraction around 0.25 is higher than those observed with mole fractions lower than 0.15 or higher than 0.35. Finally, nanostructured Cu electrodes show higher catalytic activity towards the CO2 reduction than copper electrode.