State of surface oxide films at Pt anodes and “volcano” behaviour in electrocatalysis for anodic Cl2 evolution

摘要: Abstract The kinetic behaviour of the electrolytic Cl 2 evolution reaction at Pt anodes is investigated in relation to state surface oxidation electrode. Electrode surfaces various preoxidation were examined with respect values recombination rate constant, k , for ∓ rate-controlling step that characterizes kinetics acid media. Interesting electrocatalytic effects are observed, depending on which proceeds. In particular, a clear “volcano plot” demonstrated between constant and extent as measured by reduction charge Q separate negative-going potentiodynamic sweep experiments. An optimum oxidation, corresponding an oxide film ca. 500 μC cm −2 gives highest . relationship depends, however, quite substantially mode surface, e.g. potential holding, restricted range cycling or pulsing high positive potentials. results indicate how electrocatalysis this anodic sensitive electrode surface.