Oxygen permeability and CO2-tolerance of Ce0.9Gd0.1O2−δ – SrCo0.8Fe0.1Nb0.1O3−δ dual-phase membrane

Ce0.9Gd0.1O2−δ–SrCo0.8Fe0.1Nb0.1O3−δ dual-phase membranes (CGO-SCFN DPM) with different weight ratios were successfully prepared by solid-state reaction method. The microstructure, oxygen permeability, rate-determining step, and oxygen permeation stability using CO2 as sweep gas were systematically investigated. It was found that the oxygen flux through DPM decreases with the increase of CGO content. For membranes of 80CGO-20SCFN with the thicknesses of 1.0 mm and 0.6 mm, the bulk-diffusion resistance and the interfacial exchange resistances of each side were determined according to a permeation mode. A stable oxygen flux of 0.80 mL min−1·cm2 at 900 °C for the 0.6 mm thick membrane with a porous coating on the permeate side was achieved in comparison of 0.48 mL min−1·cm2 for the 1.0 mm membrane without coating. The 80CGO-20SCFN DPM also shows a good tolerance to pure CO2, the oxygen flux could reach 0.50 mL min−1·cm2 at 900 °C.