Synthesis and oxygen permeation study of novel perovskite-type BaBi(x)Co_0.2Fe(0.8-x)O(3-δ) ceramic membranes

Novel perovskite-type B-site Bi-doped BaBi(x)Co_0.2Fe(0.8-x)O(3-δ) (0.1≤x≤0.5) oxide membranes were exploited and synthesized. Oxygen permeation through these membranes was studied by the GC method using a high-temperature permeation cell. High permeation fluxes were observed. The permeation flux of BaBi_0.2Co_0.2Fe_0.6O(3-δ) membrane reached about 1mlmin^-1cm^-2 under air/He gradients at 950°C. The dependence of the permeation flux on thickness for BaBi_0.3Co_0.2Fe_0.5O(3-δ) membrane was investigated in a wide temperature range from 600°C to 950°C. The permeation rate was controlled by surface exchange kinetics at lower temperatures. Bulk diffusion became partially rate-determining with rise in temperature. Oxygen temperature-programmed desorption (O₂-TPD) results showed very good oxygen adsorption and desorption reversibility of the materials. Copyright (C) 2000 Elsevier Science B.V.