Impact of microstructure on oxygen semi-permeation performance of perovskite membranes: Understanding of oxygen transport mechanisms

The influence of dense membrane microstructures on semi permeation performance is still not well understood, and no consensus or explanation can be established from the literature. The apparent discrepancy is likely due to a poor understanding of the oxygen transport mechanisms through the membrane and, specifically, to the impact of the microstructure on the oxygen surface exchange kinetics. The aim of this paper is to provide a better understanding of the impact of microstructures on oxygen transport mechanisms through the membrane. Two reference materials, Ba0.5Sr0.5Fe0.7Co0.3O3 (BSFCo) and La0.5Sr0.5Fe0.7Ga0.3O3 (LSFG) perovskites, are considered to explain the discrepancies observed in the literature. •Impact of the microstructure of membrane material on the oxygen flux.•Identification of the rate determining step in relation to the membrane materials.•Experimental relation between grain size and oxygen surface exchange coefficient.