An investigation was made of the permeation of normal H, and of H which was enriched with para-H, through a Pd-23%Ag membrane. At 350 to 400K, the activation energy for permeation was equal to 4.9kcal/g-atom for normal H, and equal to 3.54kcal/g-atom for H which was enriched with para-H. The differing activation energies were attributed to the differing dissociation energies of normal H and of H which was enriched with para-H.
L.Fitoussi: Comptes Rendus, 1968, 267[26], 1742-5
Table 138
Diffusivity of D in Pd-25%Ag as a Function of Concentration
[D (cm2/s) = α+ βC + γC2 + δC3]
T (C) | α | β | γ | δ | C ([H]/[M]) |
300 | 9.52 x 10-6 | 1.91 x 10-4 | -1.98 x 10-3 | 7.07 x 10-3 | 0.037-0.290 |
400 | 2.35 x 10-5 | 1.47 x 10-4 | -1.26 x 10-3 | 7.49 x 10-3 | 0.023-0.224 |
500 | 4.85 x 10-5 | -2.04 x l0-6 | 1.17 x 10-3 | 0 | 0.014-0.156 |