Electrochemical reduction of CO2 on Ag/MnO2 binary catalyst

Ag and gamma-MnO2 binary catalyst was tested as a cathode catalyst candidate for carbon dioxide reduction reaction in electrolytic cell. Prepared gamma-MnO2 was characterized by X-ray diffraction (XRD) and a field-emission scanning electron microscope (SEM). The electrocatalytic activity of Ag/gamma-MnO2 binary catalyst toward CO2 reduction was investigated by cyclic voltammetry (CV). The results of CV measurement indicated that Ag/gamma-MnO2 containing 10 wt% of silver was found to have a higher catalytic activity than carbon-supported 10 wt% Ag and improve catalytic performance as much as that of 50 wt% of carbon-supported Ag. The suggested binary catalyst with low content of Ag had a substantial improvement in catalytic activity. It is anticipated manganese dioxide plays a crucial role in electron transport and stabilization of intermediate enhancing multiple electron participation in reduction process. This result, along with its exceedingly low cost, thus suggests that gamma-MnO2 is indeed a promising co-catalyst toward CO2 reduction.