Enhancement of oxygen permeation by La0.6Sr0.4CoO3-δ coating in La0.7Sr0.3Ga0.6Fe0.4O3-δ membrane

A La0.7Sr0.3Ga0.6Fe0.4O3-δ membrane with perovskite structure is fabricated by a conventional solid-state reaction. As the oxygen permeation flux of the La0.7Sr0.3Ga0.6Fe0.4O3-δ membrane was lower than commercial gas separation membranes, we coated a La0.6Sr0.4CoO3-δ layer to enhance the oxygen permeation flux. The La0.6Sr0.4CoO3-δ coating was very effective for increasing oxygen flux, as the flux was as much as 2 to 6 times higher than that of an uncoated La0.7Sr0.3Ga0.6Fe0.4O3-δ membrane. Moreover, the oxygen permeation flux was strongly influenced by the porosity of the coating layer. XRD analysis after the oxygen permeation confirmed that Ga-based membranes have a phase stability.

La0.6Sr0.4CoO3-δ coating was very effective for the oxygen permeation flux in the La0.7Sr0.3 Ga0.6Fe0.4O3-δ perovskite inorganic membrane. In particular, the oxygen flux was strongly influenced by the porosity of the coating layer. The result indicates that the oxygen permeation flux can be controlled by the microstructure of the La0.6Sr0.4 CoO3-δ coating layer in the La0.7Sr0.3Ga0.6Fe0.4O3-δ membrane. Additionally, phase stability was confirmed at the La0.7Sr0.3Ga0.6Fe0.4O3-δ membrane and porous La 0.6 Sr 0.4 CoO 3- δ c oated La0.7Sr0.3Ga0.6Fe0.4O3-δ membrane.