Synthesis and Characterization of 40 wt % Ce₀.₉Pr₀.₁O₂−δ−60 wt % NdxSr₁₋ₓFe₀.₉Cu₀.₁O₃−δ Dual-Phase Membranes for Efficient Oxygen Separation

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.