Advances in the Kinetic Study of the Hydrogen Electrode Reaction on Metals: Theoretical and Experimental Aspects

Abstract

Advances in the interpretation of the experimental polarization curves of the hydrogen electrode reaction under the Volmer-Heyrovsky-Tafel mechanism are presented and discussed. A rigorous kinetic treatment is compared with usually employed methods, based in the separation of the faradaic current contribution and later evaluation of the Tafel regions by approximated kinetic analysis. The advanced formalism includes the simultaneous occurrence of the Volmer-Heyrovsky and Volmer-Tafel routes and the evaluation of elementary kinetic parameters by the correlation of the experimental polarization curves in the whole range of overpotentials, from hydrogen evolution to hydrogen oxidation. On its basis, the inapplicability of the approximated methods is demonstrated.