Novel La _0.7 Sr _0.3 FeO _{3 − δ} /(La _0.5 Sr _0.5 ) ₂ CoO _{4 + δ} composite hollow fiber membrane for O ₂ separation with high CO ₂ resistance

Abstract

Recently, the reported Perovskite/Ruddlesden-Popper composite with significant improvement of oxygen surface kinetics has been adopted into gas separation process. Here, we report a novel La0.7Sr0.3FeO3 − δ/(La0.5Sr0.5)2CoO4 + δ (LSF-LSC) composite hollow fiber membrane (HFM), which was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and thermal expansion test, etc. The O2 permeation test results indicated that, under sweeping gas of pure He (100 mL min−1), the composite HFM exhibited the superior O2 permeability (0.72 mL min−1 cm−2) at the temperature of 950°C with respect to the single La0.7Sr0.3FeO3 − δ (LSF) membrane, acid-etched membrane, and (La0.5Sr0.5)2CoO4 + δ (LSC)-coated membrane. Moreover, the composite membrane exhibited high CO2 tolerance as well as phase stability. The generation of hetero-interface between Ruddlesden-Popper phase and perovskite phase could be responsible for the improvement of the oxygen transportation over the fabricated composite membrane.