Kinetics of H(D)-absorption in Pd cathodes

Abstract

An experimental set-up has been built up to follow the hydrogenation (deuteration) kinetics of Pd cathodes during their electrochemical loading in galvanostatic conditions. Several Pd sheets have been loaded at different current densities in 600 ml of aqueous solution of 0.1 M LiOH. The electrolyte temperature and cathode potential against a platinum wire immersed in the same solution have been recorded during the loading process. X-ray diffraction, scanning electron microscopy and energy dispersive analyses of X-rays were used in sample characterization. The H-absorption rate has been found to depend on current density, on the other hand the H/Pd reached was ≈0.55 in all the electrolysis accomplished. A brief discussion is made on the kinetic aspects of the absorption process and the role played by the Pd surface.