BCC metal membraneVanadium Niobium Tantalum a b s t r a c t Composite membranes were fabricated by sputtering 100 nm of Pd on to both sides of dense BCC metal foils (V, Ta, Nb). Under pure H 2 gas testing at 500 C the maximum permeability of all three metals exceeds previously reported values and closely approach theoretical limits. However, the stability of each membrane varied significantly due to unique failure mechanisms. Pd/V membranes failed quickly (<20 h) due to a combination of PdeV interdiffusion and high susceptibility to oxidation as shown through microscopy and compositional analysis. The Pd/Ta membranes were the most resilient to oxygen, but their mechanical integrity was relatively poor and they failed within 48 h due to PdeTa interdiffusion. In contrast, Pd/Nb membranes exhibited high permeability throughout the 168 h of testing, with no PdeNb interdiffusion observed. The decline in permeability observed during testing was attributed to partial Pd delamination as a result of membrane deformation. These results provide pathways for further development of these membranes.

No abstract