Revisited Mechanisms for Glucose Electrooxidation at Platinum and Gold Nanoparticles

The electrooxidation of glucose on gold (Au) and platinum (Pt) nanoparticles (NPs) is investigated in alkaline medium by cyclic voltammetry after chronoamperometry at different potentials (+0.100 V, +0.200 +0.400 V vs the reversible hydrogen electrode, RHE), situ Fourier transform infrared spectroscopy, differential electrochemical mass spectrometry measurements. We show that can adsorb both metallic Au Pt surfaces low potentials, but adsorbed species are different: atoms, carbon monoxide (CO), lactones gluconate Pt-NPs, only atoms Au-NPs. On first oxidation peak between +0.050 RHE +0.250 due to adsorption into protons (H+), whereas second feature +0.800 lactone CO dioxide (CO2). For Au-NPs, not oxidized H+ transformed molecular H2, as desorbed gluconates for higher than +0.300 RHE.