Composite Membranes Based on Pd–Cu and Pd–Pb Solid Solutions

Abstract

Composite membranes with a thin selective layer based on the Pd–46 at % Cu or Pd–5 at % Pb solid solution on the surface of a bilayer heterostructure with two-level porosity in the form of Kh18N10T steel/nanoporous titanium oxide (steel/rutile) are fabricated. The structure of the selective 4-μm-thick layer is found to have no through pores, and a metal does not penetrate into the nanopores in titanium oxide. The selective layer in both versions has a fine submicrocrystalline granular structure, which is caused by the presence of a second component in the Pd–Pb layer and by a two-phase composition of the Pd–Cu layer. In the temperature range 200–300°C, the hydrogen permeability of the membrane based on the two-phase Pd–Cu solid solution is higher than the membrane based on the Pd–Pb solid solution by a factor of 1.7–2.0.