Potential dependence of methanol electrosorption on platinum

Abstract

Adsorption of methanol from acid solution onto a smooth platinum electrode is studied using fast anodic potential sweeps to determine coverages. Between 0.15 and 0.6 V (against reversible hydrogen electrode) the coverage is found to be almost independent of potential. Below 0.15 V coverage measurements are unreliable because of the very slow approach to the steady state and competition for the surface by trace impurities. The results are consistent with the hypothesis that chemisorbed methanol is a stable intermediate in a sequence of irreversible oxidation stages and that the steady-stage coverage cannot be considered as a true adsorption equilibrium.