Stability of Microtubular Membranes Based on Ba0.5Sr0.5Co0.8 – xFe0.2MoxO3 – δ Oxides

Abstract

The stability of microtubular (MT) membranes based on Ba_0.5Sr_0.5Co_{0.8 – x}Fe_0.2Mo_xO_{3 – δ} oxides (BSCFMx) prepared by the phase inversion technique is studied. It is shown that the MT membranes with the BSCFMx composition exhibit long-term stability and resistance to thermal cycling in the air/helium gradient. The maximum oxygen fluxes were obtained for MT membranes with the composition Ba_0.5Sr_0.5Co_0.75Fe_0.2Mo_0.05O_{3 – δ} (\({{J}_{{{{{\text{O}}}_{2}}}}}\) = 7.6 mL cm^–2 min^–1 at T = 850°С and pO_2.1 = 0.21 atm). A detailed equilibrium phase diagram for the BSCFM5 oxide is obtained. The absence of undesired phase transitions is demonstrated.