Analysis of the Effect of Surface Hydrogen Concentration on the Hydrogen Oxidation Reaction: Voltammetry vs. Steady State

Abstract

Starting from the modelling of the processes involved in the hydrogen oxidation reaction, the present work provides an explanation about the origin of the differences observed between the polarization curves obtained by voltammetric sweeps and those corresponding to the steady state measurements. It was demostrated that the dependence of molecular hydrogen concentration at the electrode surface on overpotential plays a key role in the current density profile. These concepts are illustated and discussed on the basis of the voltammetric response of the reaction on platinum.