Synthesis and hydrogen permeation of Ni-Ba(Zr0.1Ce0.7Y0.2) O3-δ metal-ceramic asymmetric membranes

Ni-Ba(Zr0.1Ce0.7Y0.2)O3-delta (BZCY) metal-ceramic asymmetric membranes consisted of Ni-BZCY top membrane and porous substrate were successfully prepared and developed as hydrogen permeation membrane for the first time via a method to combine co-pressing technique and two-step sintering process. The uniform fine NiO-BZCY composite powders as the precursor of top membranes were co-synthesized through the citrate-nitrate combustion route (co-synthesis method), which was the key to fabricating Ni-BZCY thin membrane. The homogeneity and phase structure of two phases in powders were characterized using element-map technique and X-ray diffraction analysis, respectively. The fluxes through a metal-ceramic membrane of about 30-mu m-thickness were measured as a function of temperature under different feed gas hydrogen partial pressures. The results indicated the asymmetric membrane displayed high hydrogen permeation flux and using 80%H-2/N-2 (with 3% of H2O) as feed gas and dry high purity argon as sweep gas, a maximum flux of 2.4 x 10(-7) mol cm(-2)s(-1) was achieved at 900 degrees C, exhibiting the predominance of asymmetric structures. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.