Synthesis and Characterization of 40 wt % Ce(0.9)Pr(0.1)O(2–δ)–60 wt % Nd(x)Sr(1−x)Fe(0.9)Cu(0.1)O(3−δ) Dual-Phase Membranes for Efficient Oxygen Separation

Dense, H(2)- and CO(2)-resistant, oxygen-permeable 40 wt % Ce(0.9)Pr(0.1)O(2–)(δ)–60 wt % Nd(x)Sr(1−x)Fe(0.9)Cu(0.1)O(3−)(δ)dual-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 Ce(0.9)Pr(0.1)O(2−)(δ)–Nd(0.5)Sr(0.5)Fe(0.9)Cu(0.1)O(3−)(δ) sample demonstrates outstanding activity and a regenerative ability in the presence of different atmospheres, especially in a reducing atmosphere and pure CO(2) atmosphere in comparison with all investigated samples. The oxygen permeation fluxes across a Ce(0.9)Pr(0.1)O(2−)(δ)–Nd(0.5)Sr(0.5)Fe(0.9)Cu(0.1)O(3−)(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/CO(2) gradient at T = 1223 K, respectively. In addition, a Ce(0.9)Pr(0.1)O(2–)(δ)–Nd(0.5)Sr(0.5)Fe(0.9)Cu(0.1)O(3–)(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.