In order to assess membrane architecture-related effects on the O transport through ferrite-based mixed conductors, a series of planar ceramic membranes with dense layers made of the dual-phase (SrFeO3−δ)0.7(SrAl2O4)0.3 composite were appraised at 1023 to 1223K under oxidizing conditions. The asymmetrical membranes with porous La0.5Sr0.5FeO3−δ and (SrFeO3−δ)0.7(SrAl2O4)0.3 supports were fabricated by a 2-stage compaction procedure using various pore-forming additives and sintering at 1623–1723K. Analysis of the O permeation fluxes through model symmetrical membranes showed significant limiting role of the composite surface O exchange. At temperatures above 1173K, a substantially improved performance was observed for asymmetric self-supported composite membranes with the dense layer thickness of 0.12mm, surface-modified with (SrFeO3−δ)0.7(SrAl2O4)0.3–Pt mixture. At 1023 to 1173K, higher O fluxes were achieved using perovskite-type La0.5Sr0.5FeO3−δ as the porous support material.

Processing and Oxygen Permeability of Asymmetric Ferrite-Based Ceramic Membranes. A.V.Kovalevsky, V.V.Kharton, F.M.M.Snijkers, J.F.C.Cooymans, J.J.Luyten, J.R.Frade: Solid State Ionics, 2008, 179[1-6], 61-5