Free-standing Pd/Ag23wt% membranes of 5 different thicknesses ranging from about 1.3 to about 5.0μm were prepared by magnetron sputtering. The H permeation was determined before and after heat-treatment in air at 300C. In all of the membranes studied, the heat treatment resulted in enhanced permeation. For some membranes, the H flux more than doubled. A permeance of 1.7 x 10−2mol/m2sPa0.5 was observed for 1.3μm-thick membranes; was one of the highest reported. Bulk diffusion was found to be the main rate-limiting step after heat treatment in air. The permeability was quite similar for all of the membranes studied after this treatment, with a mean value of 2.1 x 10−8molm/m2sPa0.5. Topographic studies, using atomic force microscopy, showed that the samples which were heat-treated in air had a higher surface roughness, larger surface area and larger surface grains than did samples which were not heat-treated in air.

Hydrogen Permeation of Thin, Free-Standing Pd/Ag23% Membranes before and after Heat Treatment in Air. A.L.Mejdell, H.Klette, A.Ramachandran, A.Borg, R.Bredesen: Journal of Membrane Science, 2008, 307[1], 96-104