(478e) Effect of pH on the Electrocatalytic Oxidation of Glycolic Acid

Both bulk and near- (electrode) surface electrolyte properties alter electrocatalytic reaction activity and selectivity. The electrolyte pH dictates protonation/deprotonation equilibria in the bulk as well as the near-surface electric field and ion concentration, each of which can impact the mechanism of a given catalytic reaction. Using detailed measurements on a Pt (111) single crystal electrode, we examine the pH dependence of the kinetics of electrocatalytic glycolic acid oxidation. Though at acidic pH no significant reactions were observed apart from glycolate adsorption, with an increase in pH the rate of the glycolate oxidation reaction increases. We make a comparison to the pH dependence of the oxidation of other similar, small molecules, such as formic acid (Joo et al., 2014). We expect that by understanding the mechanism of the oxidation of many functionalized small organic molecules, we can build a more complete picture of the oxidation of larger, more complex molecules, such as those found in bio-oil and during biomass-derived organics electrochemical upgrading.

Reference:

1. Joo, J., Uchida, T., Cuesta, A., Koper, M. T. M., & Osawa, M. (2014). The effect of pH on the electrocatalytic oxidation of formic acid/formate on platinum: A mechanistic study by surface-enhanced infrared spectroscopy coupled with cyclic voltammetry. Electrochimica Acta, 129, 127–136. https://doi.org/10.1016/j.electacta.2014.02.040