“…The second one is that the surface microstructure changes under oxygen permeation condition can speed up the oxygen exchange rates, which has been verified by our previous investigation [50]. The third is that the adsorption of CO 2 on membrane surface retards oxygen exchange rates and decreases the oxygen permeation flux [3,7,40,57]. For the SDC67-SCC33 membrane, the three factors exhibit their effects at different stages.…”