Formate was found to be the only adsorbed species detected with time-resolved ATR-SEIRAS during the electrooxidation of formic acid on Au in acidic media. No adsorbed CO was detected, since even in CO-saturated acidic solutions the adsorption of CO on gold is negligible. The onset of formic acid electrooxidation coincides with that of formate electroadsorption, pointing to bridge-bonded adsorbed formate as the reaction intermediate. Furthermore, at constant potential the current increases quadratically with the formate coverage, which indicates that the rate-determining step in the oxidation of adsorbed formate to CO2 is a bimolecular reaction between adjacent formate species. The rate of this reaction was unaffected by potential changes, which unequivocally confirms its chemical character.
- formic acid
- direct path
- absorbed formate
Cuesta, A., Cabello, G., Hartl, F. W., Escudero-Escribano, M., Vaz-Dominguez, C., Kibler, L. A., Osawa, M., & Gutierrez, C. (2013). Electrooxidation of formic acid on gold: An ATR-SEIRAS study of the role of adsorbed formate. Catalysis Today, 202, 79-86. https://doi.org/10.1016/j.cattod.2012.04.022