Permeation of Hydrogen in Palladium

Abstract

Experimental studies on the permeation of hydrogen in a palladium plate 1-2×10 -4 m in thickness were carried out at a constant temperature under the application of a constant hydrogen pressure in the respective ranges from 261 to 191 K and from 66.5 to 2660 Pa. Hydrogen permeabilities obtained in the permeation experiment are expressed by the formula kkD exp (ΔH/k B T), where K and D are the solubility constant and the diffusion coefficient, respectively. The factor k is a share rate of time, expressing the time needed for the bulk diffusion to bring forth the permeation by kt, where t is the total time of observation of permeation, and ΔH is the increase of the heat of solution of hydrogen, relative to the bulk, in the subsurface layers, where k=1/2 and ΔH=3.16×10 -21 J (0.046eV).