Dense, H2- and CO2-resistant, oxygen-permeable 40 wt % Ce0.9Pr0.1O2-δ-60 wt % NdxSr1-xFe0.9Cu0.1O3-δdual-phase membranes were prepared in a one-pot process. These Nd-containing dual-phase membranes have up to 60% lower material costs than many classically used dual-phase materials. The Ce0.9Pr0.1O2-δ-Nd0.5Sr0.5Fe0.9Cu0.1O3-δ sample demonstrates outstanding activity and a regenerative ability in the presence of different atmospheres, especially in a reducing atmosphere and pure CO2 atmosphere in comparison with all investigated samples. The oxygen permeation fluxes across a Ce0.9Pr0.1O2-δ-Nd0.5Sr0.5Fe0.9Cu0.1O3-δ membrane reached up to 1.02 mL min-1 cm-2 and 0.63 mL min-1 cm-2 under an air/He and air/CO2 gradient at T = 1223 K, respectively. In addition, a Ce0.9Pr0.1O2-δ-Nd0.5Sr0.5Fe0.9Cu0.1O3-δ membrane (0.65 mm thickness) shows excellent long-term self-healing stability for 125 h. The repeated membrane fabrication delivered oxygen permeation fluxes had a deviation of less than 5%. These results indicate that this highly renewable dual-phase membrane is a potential candidate for long lifetime, high temperature gas separation applications and coupled reaction-separation processes.
Keywords: CO2 tolerance; dual-phase membrane; long-term stability; oxygen separation; regenerative ability.