Preparation and properties of perovskite-dispersed titania membranes

Defect-free SrCo_{0 8}Fe_{0 2}0₃ perovskite-dispersed titania (perovskite-titania) membrane was successfully prepared by sol-gel method combined with wet impregnation process. In this experiment, titania membrane was immersed in a perovskite solution, dried and calcined to obtain perovskite dispersed in titania membrane. The phase composition and membrane morphology of the membrane were characterized by thermogravimetric analysis (TGA), X-Ray Diffraction (XRD) spectroscopy, Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). The TEM result demonstrated that perovskite particles were well-dispersed among the titania particles. The SEM analysis showed that a uniform membrane approximately 0.5 μm thick on titania support was obtained after multiple coatings and calcination at 400°C. 0₂ and N₂ permeability across the perovskite-titania membrane was measured to investigate membrane performance. From the permeability result, both gases appeared to decrease as the operating temperature increased, indicating that surface diffusion gradually reduced. The separation of 0₂ from its binary mixtures containing N₂ was possible because the value of separation factor N₂/0₂ was slightly higher than the theoretical Knudsen diffusion.