Datensatz

Zusammenfassung

The cathodic hydrogen peroxide, H2O2, reduction in HClO4 proceeds by two parallel mechanisms, the “normal” H2O2 reduction, and a remarkable autocatalytic reaction path. Chemisorbed hydroxyl groups OHad, formed as an intermediate on the silver electrode, are considered to constitute the autocatalytically active species. In order to obtain a clearer conception of the species OHad, the state of Ag(111) electrodes in inert electrolytes of varying pH is analysed with electrochemical and surface science tech-niques. Experiments with Second Harmonic Generation yield particularly valuable results. The surface studies, along with numerical simulations of the adsorption dynamics, indicate that the species OHad is identical with the discharged surface hydroxyl species formed as a relatively stable intermediate in the anodic oxidation of OH- to surface-Ag2O.