Preparation of Mixed Ionic Electronic Conducting (MIEC) Membrane Supported on Al₂O₃ Substrate: Effects of Substrate Morphology

Two types of solvents [N-methyl-2-pyrrolidone (NMP) and dimethyl sulfoxide (DMSO)] were used in the preparation of alumina (Al₂O₃) dope suspensions whereby the dope was allowed to experience phase inversion in the coagulation bath. The green body of alumina discs were sintered at 1450°C and the morphologies of prepared alumina-NMP and aluminaDMSO were studied. To improve the catalytic activity of the oxygen transport membrane for oxygen separation purposes, surface modifications of the membranes were carried out using different mixed ionic electronic conducting (MIEC) oxides catalysts (LCF 91 and LSF 55). The oxide powders and viscous sol were synthesised using sol-gel method and calcined at 950°C to form pure perovskite structure of MIEC materials and studied using XRD while the specific surface area of the calcined powder was measured using BET (Brunauer-Emmett-Tellet) technique. The honey-like MIEC sols were used for surface modification and conducted via dip-coating method and the morphology of the surface-modified alumina membranes were analysed using SEM with EDS mapping. From the study, it was found that the amount of MIEC oxide deposited onto alumina-DMSO is higher than alumina-NMP.