Insights of Fe₂O₃ and MoO₃ Electrodes for Electrocatalytic CO₂ Reduction in Aprotic Media

Transition metal oxides (TMO) have been successfully used as electrocatalytically active materials for CO₂ reduction in some studies. Because of the lack of understanding of the catalytic behavior of TMOs, electrochemical methods are used to investigate the CO₂ reduction in thin-film nanostructured electrodes. In this context, nanostructured thin films of Fe₂O₃ and MoO₃ in an aprotic medium of acetonitrile have been used to study the CO₂ reduction reaction. In addition, a synergistic effect between CO₂ and the TMO surface is observed. Faradic cathodic processes not only start at lower potentials than those reported with metal electrodes, but also an increase in capacitive currents is observed, which is directly related to an increase in oxygen vacancies. Finally, the results obtained show CO as a product of the reduction.