Oxygen-permeable membranes derived from SrFe 0.2Co 0.8O 3-δ were investigated aiming at improving the permeability and integrity. An oxygen flux as large as 1.52×10 -6 mol/(cm 2·s) was observed for a 0.1 cm thick membrane of Ba 0.1Sr 0.9Sn 0.1Fe 0.1Co 0.8O 3-δ at 900 ℃ under a relatively small oxygen partial pressure gradient across the membrane(P′ O 2=2.13×10 4 Pa, P″ O 2=9.12×10 2 Pa ). The improved oxygen permeability may be attributed to the weaker association of oxygen vacancies as a consequence of partial substitution of Ba for Sr. The improved membrane stability of Sn-doped sample is likely due to the formation of SrSnO 3 second phase since the non-crystal Sr in grain boundaries is prior to reacting with Sn, which made the membrane more resistant to the corrosion from CO 2 and water vapor.
