The Hydrogen Evolution Reaction on Fe Electrode Material in 1 M NaOH Solution

Abstract

Kinetics of hydrogen evolution reaction (HER) was investigated in 1 M NaOH solution at room temperature on a polycrystalline Fe electrode material which was electrochemically activated and unactivated. Studies of the HER were carried out using steady-state polarization and electrochemical impedance spectroscopy (EIS) measurements. It was found that for the Fe electrode material after activation atj= -320 mA cm-2for 24 h, the increase in the catalytic activity towards the HER was observed in comparison with that on the unactivated iron electrode material.Acimpedance behavior of the Fe electrode changed from a typical for smooth electrodes before activation (one time constant in the circuit) to that being characteristic for porous electrodes after activation (two time constants in the circuit). The reason for that is formation of solid products of the iron corrosion in alkaline solution which can cause passivation of the electrode surface and catalyse the HER.