Electrochemical Impedance Study on the Kinetics of Hydrogen Evolution at Amorphous Metals in Alkaline Solution

Abstract

The mechanism of the hydrogen evolution reaction on the amorphous metals and in at has been studied by electrochemical impedance spectroscopy in the frequency range . Comparative measurements were carried out on polycrystalline Ni and Pt electrodes. Analysis and discussion of the data is based on a theoretical transfer function derived for the Volmer‐Tafel reaction mechanism. Formal rate constants could be obtained from a nonlinear least squares fit of the impedance data and were compared with previous results obtained from an analysis of steady‐state polarization curves. Participation of surface and/or bulk diffusion steps of H atoms at low overpotentials is indicated on by a time constant arising at low frequencies in the impedance spectra.