Steady-state permeation studies and gas-volumetric measurements were used to investigate the diffusion of H and D (table 135). In these tests, the low-pressure side of the diffusion cell was kept at 1atm, while the pressure on the high-pressure side was varied from 1 to 17atm. The Pd used was of 3N-purity, and the D was of 2N7-purity. When the D or H concentration was low, the results between 20 and 100C could be described by:

H:     D (cm2/s) = 3.65 x 10-3 exp[-5.6(kcal/g-atom)/RT]

D:     D (cm2/s) = 2.5 x 10-3 exp[-5.15(kcal/g-atom)/RT]

G.Bohmholdt, E.Wicke: Zeitschrift für Physikalische Chemie, 1967, 56[3-4], 133-54

Table 135

Parameters for H and D Diffusion in Pd Alloys at 20 to 100C