Overpotential decay transients and the reaction mechanism on the Pd-H 2 electrode

Abstract

Cathodic overpotentials and overpotential decay transient curves for a smooth Pd-H 2 electrode were measured in H 2SO 4 solutions. The overpotential component that remained at about 10 -4s after interruption of the polarization current increased linearly with the logarithm of current density with a slope of about 40 mV decade -1 and its magnitude was practically independent of the solution pH. The total overpotential was pH dependent. On the basis of these observations we concluded that the Tafel-Volmer mechanism was operative. This conclusion differs from the one reported previously on porous electrodes prepared by electrodeposition.