Based on theories of H electrode reactions at the Pd surface and self-stresses of H in thin tubular shells established earlier, transport properties of H across a tubular membrane under galvanostatic charging conditions were calculated numerically. It was found that the exited H flux was much less than the charging current since the H combination reaction took place at the outer surface. On the other hand, the overall system was in an unstable state after long-term charging. This made the determination of H diffusivity difficult in experiments. The theoretical results were in good agreement with previous experimental data.

Effects of Electrochemical Reaction and Self-Stress on Hydrogen Diffusion in Tubular Membranes during Galvanostatic Charging. W.S.Zhang: Journal of Alloys and Compounds, 2003, 356-357, 314-7