Examining the Electrocatalytic Oxidation of Selected Diols at Nanoporous and Planar Pt Electrodes

We report on the electrocatalytic oxidation of 1,3-propanediol and the four butanediols at nanoporous Pt and planar solid Pt electrodes under basic conditions. We consider the reactant and Pt morphology dependencies of the electrocatalytic oxidation reactions seen for the diols. Our experimental data point to the oxidation pathway for the diols depending sensitively on the proximity of the hydroxyl groups to one another, with relatively less dependence on whether the hydroxyl functionalities are at primary or secondary positions. For vicinal diols, there are two resolvable oxidation steps, whereas for the 1,4- and 1,3-diols, the multiple processes contributing to the observed oxidation wave are not clearly resolvable. The data for two 1,3-diols show no current density enhancement for nanoporous Pt electrodes, underscoring the central role that the Pt electrode surface morphology plays in determining reaction efficiency.