Fabrication, characterization, and application of palladium composite membrane on porous stainless steel substrate with NaY zeolite as an intermediate layer for hydrogen purification

Abstract

Palladium composite membrane with excellent stability was successfully prepared using the electroless plating (ELP) route on a porous stainless steel (PSS) support for hydrogen separation. In order to modify the average pore size of PSS support and to prevent inter-metallic diffusion, the NaY zeolite layer was coated on the PSS support with the seeding and secondary growth method. A high-temperature membrane module was designed by Solid work software and fabricated from 316 L stainless steel with a knife-edge seal. The microstructures and morphologies of the samples were analyzed using XRD, BET, AFM, FESEM and EDX techniques. Permeation experiments were carried out with binary mixtures of H2/N2 with various ratios (90/10, 75/25 and 50/50) and pure H2 and N2 at different temperatures (350, 400 and 450 °C) and feed pressures (200–400 kPa). Hydrogen permeation tests showed that the membrane with a thickness of about 7 μm had a hydrogen permeance of 6.2 × 10−4 mol m−2 s−1 Pa−0.5 with an ideal H2/N2 selectivity of 736, at 450 °C. In addition, the results of stability tests revealed that the membrane could remain stable during a long-term operation by varying temperature and feed gases.