H diffusion through partially internally oxidized Pd-alloy membranes

The H flux (J) has been measured through multilayer membranes of Pd and Pd–Al alloy prepared by internal oxidation of the alloy. A plot of 1/J against thickness of the Pd layers, 2dPd, is linear for a series of different 2dPd values. This justifies assumptions of the model used to derive the relation between 1/J and 2dPd. DH for Pd and the alloy can be obtained from intercepts of the plot using known pH2pH2–H content isotherms. Since it has been shown that internal oxidation leads to more reproducible and poison-resistant Pd based membranes, the multilayer technique is an alternate way to obtain DH for Pd alloys.