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We show here that palladium-lutetium foil Pd–11.2 wt % Lu membrane can be efficiently used for hydrogen separation via its diffusion at temperatures 300–500°С. Several correlations of the membrane structure morphology and the specific permeability of the membranes are considered. Particular attention is placed in analysis of the membrane surface studied by atomic force microscopy using the phase contrast mode. The studies performed are addressed the problem of the membrane durability for the cyclic operation up to 40 h in hydrogen atmosphere. [ABSTRACT FROM AUTHOR]

The purity of hydrogen, which is an alternative energy carrier in powder sources of distributed energy resource systems and, in particular, is the feed stock for fuel cells, should be no less than 99.9999 vol % purity High-purity hydrogen can be prepared only via its separation as a result of selective diffusion through metallic membranes manufactured from specific membrane palladium-based alloys prepared in the form of thin foils. In the present work, the combination of deformation and annealings under different conditions is used to prepare the Pd–7.70 wt % Lu alloy in the form of foil 50 µm thick, whose specific hydrogen permeability is studied in the course of cyclic heating and cooling in a hydrogen atmosphere in a temperature range of 300–500°С. The Pd–7.70 wt % Lu membrane is shown to demonstrate high and stable hydrogen permeability. The evolution of the surface structure of the membrane in the course of its operation in the hydrogen atmosphere is studied by atomic force microscopy using the phase contrast mode. [ABSTRACT FROM AUTHOR]