Palladium (Pd) membranes on porous stainless steel (PSS) were prepared by electroless plating. An intermediate layer of NaX nanozeolite was employed to modify the pore size of the PSS support and improve the hydrogen permeability. NaX nanozeolites were synthesized using convectional hydrothermal method. The NaX intermediate layer was coated by vacuum-assisted method on the PSS surface. The structure and morphology of the prepared membranes were characterized using SEM, XPS and XRD analysis. Permeation measurements were conducted using H-2, N-2 and mixture of H-2/N-2 at different temperatures (350-450 degrees C), and trans-membrane pressures (4-8 bar). The results indicated that the permeability and hydrogen selectivity were increased by enhancement in temperature and pressure. The hydrogen fluxes in H-2/N-2 mixtures were lower than those corresponding to pure hydrogen at the same partial pressures and temperatures. The obtained results suggests that the use of NaX nanozolite is an effective intermediate layer in Pd/PSS membranes for hydrogen separation. (C) Copyright 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.