Data for journal article: Stability of electrodeposited manganese oxide films under electrochemical carbon dioxide reduction conditions

This is the data from the paper: Stability of electrodeposited manganese oxide films under electrochemical carbon dioxide reduction conditions. Paper abstract: Electrodeposition of manganese oxide onto a boron-doped diamond electrode substrate was carried out, to explore the application of the films as an electrocatalyst for CO2 reduction. The films were characterized as δ-MnO2 using Raman spectroscopy and x-ray photoelectron spectroscopy. The films were found to remain intact but to undergo partial reduction to Mn3O4 at -1.0 V in N2-saturated 0.1 M KHCO3 electrolyte. However, when the solution was saturated with CO2 the δ-MnO2 film underwent significant dissolution, indicating the formation of solution Mn(II) products. This result was attributed to the more acidic pH of the CO2 saturated solution. Given that such Mn oxide materials have been reported as successful CO2 reduction electrocatalysts under identical conditions, this result was unexpected, but could be explained by a decreased kinetic stability of the electrodeposited film compared to Mn oxide materials prepared by other methods. Some mitigation approaches to improve the stability of the electrodeposited films are therefore proposed.