In situ Fourier transform infrared reflection absorption spectroscopic studies of glucose oxidation on platinum in acid

Electrochemical oxidation of α-D( + )-glucose on a polycrystalline platinum electrode in 0.1 M HC1O₄ was studied in situ by Fourier transform infrared reflection-absorption spectroscopy. The spectra showed unambiguously that the major adsorbate on the platinum surface during the glucose oxidation over the potential range -0.20 to +0.40 V vs. a saturated calomel reference electrode is linearly adsorbed CO. The strong adsorption of this species inhibits the electrode reaction. The oxidation products in the solution were found to be gluconolactone, carboxylic acids and CO₂ whose formation occurred to the greatest extent in the platinum oxide region.