Enhanced CO 2 Resistance for Robust Oxygen Separation Through Tantalum‐doped Perovskite Membranes

Oxygen selective membranes with enhanced oxygen permeability and CO 2 resistance are highly required in sustainable clean energy generation technologies. Here, we present novel, cobalt‐free, SrFe 1− x Ta x O 3− δ ( x =0, 0.025, 0.05, 0.1, 0.2) perovskite membranes. Ta‐doping induced lattice structure progression from orthorhombic ( x =0) to cubic ( x =0.05). SrFe 0.95 Ta 0.05 O 3− δ (SFT0.05) showed the highest oxygen flux rates reaching 0.85 mL min −1  cm −2 at 950 °C on a 1.0 mm‐thick membrane. Surface decoration can increase the permeation rate further. Ta inclusion within the perovskite lattice of SrFeO 3− δ (SF) enhanced the CO 2 resistance of the membranes significantly as evidenced by the absence of the carbonate functional groups on the FTIR spectrum when exposed to CO 2 atmosphere at 850 °C. The CO 2 resistance of Ta‐doped SF compounds correlates with the lower basicity and the higher binding energy for the lattice oxygen. SFT0.05 demonstrated high stability during long‐term permeation tests under 10 % CO 2 atmosphere.