Synthesis And Property Of Mixed Conducting Materials For Oxygen Permeation

By combining the air separation and the catalytic partial oxidation of methane (POM) to syngas into one reactor, dense ceramic reactor technology, which is considered as the key of the one of the most promising routes for methane conversion, is expected to significantly reduce the capital costs of conversion of natural gas to liquid added-value products, and enhance the reliability and performance of the POM reaction. Based on the special mixed ionic-electronic conducting (MIEC) ability at high temperatures (typically above 973K), MIEC oxides not only showed promising possibility as the membrane materials in catalytic membrane reactor, but also had wide applications in oxygen separation, oxygen-enriched combustion and solid oxide fuel cell (SOFC). Related researches also gather the theories and techniques of Chemical Engineering, Catalysis and Materials, and are forming a new field in membrane science.In order to meet the needs of the conversion of natural gas in the engineering applications, the present researches started with the basic relationships among the composition, structure, synthesis and property of MIEC oxides with the aid of the advanced characterization methods of materials and the high temperature oxygen permeation / partial oxidation of methane (POM) measurements in our laboratory. Most of the attentions were focused on the design, exploitation, synthesis and application of MIEC oxides, which classified the present researches into three parts:1. Synthesis and properties of a novel Al₂O₃-doped SrCo0.8Fe0.2O3-δMIEC oxides Based on the theories of the material design in our group, a new series of Al₂O₃-doped SrCo0.8Fe0.2O3-δ(SCFA) MIEC oxides were synthesized by directly doping Al3+ into the SrCo0.8Fe0.2O3-δ(SCF) phase, a perovskite-type oxide with excellent oxygen permeability but limited stability (especially in the POM reaction). By systematically investigating the dependences of composition, structure and property of SCFA on the doping amount of Al₂O₃ (1, 3, 5 and 10 wt.%), we found that (1) The solid solubility of Al₂O₃ in SCF was between 3-5wt.%, near which the...