Synthesis and oxygen permeation study of novel perovskite-type BaBixCo0.2Fe0.8−xO3−δ ceramic membranes

Novel perovskite-type B-site Bi-doped BaBixCo0.2Fe0.8−xO3−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 BaBi0.2Co0.2Fe0.6O3−δ membrane reached about 1 ml min−1 cm−2 under air/He gradients at 950°C. The dependence of the permeation flux on thickness for BaBi0.3Co0.2Fe0.5O3−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.