The catalytic membrane reactors studied here consisted of a mixed ionic and electronic conductor dense layer (La(1−X)SrXFe(1−Y)GaYO3−δ). High temperature X-ray diffraction analysis, from room temperature to 900C under air and nitrogen atmosphere, showed a reversible monoclinic to rhombohedral phase transition around 300C, and good chemical and dimensional stabilities of La0.8Sr0.2Fe0.7Ga0.3O3−δ material. The La0.8Sr0.2Fe0.7Ga0.3O3−δ dense layer elaborated by tape casting was respectively coated with La0.8Sr0.2Fe0.7Ga0.3O3−δ on the air side and La0.8Sr0.2Fe0.7Ni0.3O3−δ on the inert side using screen printing. The influences of the dense membrane microstructure and of the surface exchange kinetics on the oxygen semi-permeation performances were evaluated. Small grain size, mainly below 1 μm in the dense membrane significantly increases the oxygen flux. A porous layer of La0.8Sr0.2Fe0.7Ni0.3O3−δ or La0.8Sr0.2Fe0.7Ga0.3O3−δ on the air or inert side of the membrane increased strongly the specific oxygen semi-permeation. The impact of the porous layer was much more important than the reduction of the grain size. In this case, surface exchange kinetics were the limiting steps of oxygen permeation, and Ni-containing formulation led to the highest flux.

Influence of Microstructure and Architecture on Oxygen Permeation of La(1−X)SrXFe(1−Y)(Ga, Ni)YO3−δ Perovskite Catalytic Membrane Reactor. E.Juste, A.Julian, P.M.Geffroy, A.Vivet, V.Coudert, N.Richet, C.Pirovano, T.Chartier, P.Del Gallo: Journal of the European Ceramic Society, 2010, 30[6], 1409-17