The diffusion of H in 3N-purity Pd and various Pd-Ag alloys (prepared from 3N5-purity Pd and 5N-purity Ag) was studied (table 132) by using sensitive permeation cell and time-lag techniques. At 260 to 640C, and compositions ranging up to 50%Ag, the results could be described by:

D (cm2/s) = A exp[-B(cal)/RT]

where B was equal to,

38000x4 + 1500x2 + 5260

and A was equal to,

-0.00265x + 0.0029

Here, x was the mole fraction of Ag.

Diffusion and Solubility of Hydrogen in Palladium and Palladium--Silver Alloy. G.L.Holleck: Journal of Physical Chemistry, 1970, 74[3], 503-11

Table 132

Parameters for H Diffusion in Pd-Ag at 260 to 640C