The effect of electrical parameters, surface roughness, surface contamination and electrolyte concentration (NaOH or H2SO4 solution) upon the permeation rate through a 0.05mm Pd membrane was reported. Diffusion measurements were carried out using an electrochemical permeation cell under transient conditions. The cathodic side of the membrane was subjected to a constant concentration or flux, while the anodic side was kept permanently at a negligibly low concentration. The diffusion coefficient was deduced from the charging or stripping current, as expressed as a function of time. Reliable values were obtained only from stripping curves under potentiostatic charging conditions. It was found that, at 5 to 50C, the diffusion of H could be described by:

D (cm2/s) = 2.48 x 10-3 exp[-5.21(kcal/mol)/RT]

R.V.Bucur: Zeitschrift für Physikalische Chemie, 1985, 146[2], 217-29