The permeability of membranes to H was investigated, before and after exposing them to a glow-discharge plasma. It was noted that a preliminary treatment of activated material (which had been subjected to long-term annealing in vacuum at about 1000K) by means of a glow-discharge plasma did not cause any changes in permeability. The effects of plasma-treating a partially activated sample (which had been heated for 1h in vacuum) depended greatly upon the irradiation conditions. When treated in the cathodic regime (with the membrane serving as a cathode), the rates of surface permeability processes increased. When compared with the effect of H heat-treatment, the time required to attain permeability conditions which corresponded to the activated state was reduced. The effects of bombarding the membrane surface with H+, He+ and Ar+ were monitored via determinations of the methane yield during annealing. The results indicated that the permeability activation effect was caused by decarburization. Treatment in the anodic regime caused a decrease in the rate of H permeation. This was attributed to the presence of thin films.

G.P.Glazunov: International Journal of Hydrogen Energy, 1997, 22[2-3], 263-8