Pd and Pd-Ni alloy composite membranes fabricated by electroless plating method on capillary α-Al2O3 substrates

Novel home-made porous capillary alpha-Al2O3 substrates were used as mechanical supports for the Pd-based composite membranes for hydrogen permeation. The rough surface of the substrates with large open pores were modified by vacuum sol-gel dip-coating followed by high temperature calcination treatment. After the introduction of the electroless plating catalysts of Pd particles on the modified surface by an improved catalyzing process, the defect-free Pd and Pd-Ni alloy thin membranes were deposited by cost-effective and facile electroless plating technique. The Pd composite membranes showed a hydrogen permeance of 2.55 x 10(-3) mol/(s m(2) Pa-0.5) at 500 degrees C, and 730 for the permselectivity of H-2/N-2. The Pd-Ni alloy composite membranes showed a hydrogen permeance of 2.74 x 10(-3) mol/(s m(2) pa(0.5)) and 640 for the permselectivity of H-2/N-2 at the same temperature. The Pd and Pd-Ni membranes showed good long-term permeation stability at 500 degrees C under hydrogen permeation condition. Moreover, the Pd-Ni alloy composite membrane showed a better hydrogen permeation stability of more than 100 h at 300 degrees C under hydrogen permeation condition without obvious hydrogen embrittlement occurred. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.