The Effects of Multiple Electroplated Zinc Layers on the Inhibition of Hydrogen Permeation Through an Iron Membrane

Abstract

The Devanathan-Stachurski permeation technique 1-3 was used to investigate the rate of hydrogen permeation through an iron membrane with consecutively electroplated zinc layers. Hydrogen evolution rates and hydrogen permeation rates were followed as functions of time at different applied potentials. Hydrogen evolution and permeation decrease with each successive zinc layer until finally reaching an average decrease of 93 and 96%, respectively, as compared with bare iron. Hydrogen surface coverage, exchange, current density, absorption-adsorption reaction constant, and hydrogen recombination constant were estimated on bare iron and on zinc-plated iron. It was found that the decrease in the permeation rate of hydrogen through the iron membrane was due to (i) the decrease of hydrogen discharge rate and (ii) the suppresion of hydrogen absorption and adsorption on the deposited zinc layers.