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.