Enhancing the oxygen permeation rate of Ba0.5Sr0.5Co0.8Fe0.2O3 − δ membranes by surface loading Co3O4 nanorod catalysts

• Co3O4 nanorod catalysts were self-assembled on the surface of Ba0.5Sr0.5Co0.8Fe0.2O3 − δ membranes.
• Co3O4 nanorod catalyst improves the surface exchange reaction of BSCF membrane.
• With the modification of Co3O4 catalysts, the oxygen permeation rate of BSCF membrane was significantly improved.

To modify the oxygen permeability of Ba0.5Sr0.5Co0.8Fe0.2O3 − δ (BSCF) membrane, Co3O4 nanorod catalysts were self-assembled onto the surface of the BSCF membrane by a hydrothermal process. Phase structures and morphology of the BSCF membrane self-assembled with Co3O4 nanorod catalysts were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that Co3O4 nanorods with spinel structure and of about 100 nm in diameter and 3 μm in length were grown on the surfaces of BSCF membrane. The loading of Co3O4 nanorods can effectively improve the oxygen permeability of BSCF membrane. At 600 °C, the oxygen permeation rate of BSCF membrane with 1 mm in thickness modified by Co3O4 nanorod catalysts reaches 0.47 ml · min− 1 · cm− 2, which is 11.5 times higher than that of the bare BSCF membrane under Air/He gradient. At 850 °C, the oxygen permeation rate of the modified BSCF membrane reaches 1.76 ml · min− 1 · cm− 2, which is 0.3 ml · min− 1 · cm− 2 higher than that of bare BSCF membrane.