Tantalum stabilized SrCoO3−δ perovskite membrane for oxygen separation

The mixed ion and electron conducting oxides of SrCo1−yTayO3−δ (0 ≤ y ≤ 0.3) powders were prepared by solid state reaction. By doping 10 mol% of tantalum on the B-site of SrCoO3, the cubic perovskite structure of the SrCoO3 is stable and a high oxygen permeation flux is achieved. The phase structure of the perovskite-type oxide of SrCo0.9Ta0.1O3−δ was characterized by X-ray diffraction (XRD) and oxygen temperature-programmed desorption (O2-TPD) revealing that SrCo0.9Ta0.1O3−δ exhibits a good phase structure stability and reversibility in air. The oxygen permeation is predominated by oxygen ion bulk diffusion at the temperature ≥ 900 °C. During the long-term operation, the SrCo0.9Ta0.1O3−δ membrane is operated at 900 °C for more than 520 h with a steady oxygen permeation flux of around 1.36 × 10−6 mol/s cm2 with a membrane thickness of 0.65 mm under He/air gradient.