| Summary: | 碩士 === 國立雲林科技大學 === 工業化學與災害防治研究所 === 94 === Abstract
The purpose of this study was to prepare develop nano-particle Zn-Ti mixed oxide aerogel and obtaininvestigate relation of their tiny structures with surface and electrical properties. The work used the sol-gel method to synthesize Zn-Ti oxide colloid solution and the supercritical fluid drying to form aerogel powders. The particle shape aerogel was identified as with HRTEM and FESEM and size was measured to be 10 nm. The X-ray diffraction spectra showed crystalline phases of zinc titanium oxide(Zn2Ti3O8) and Anatase. O2- deficiencies existed on the surface of aerogel as analyzed by XPS.
These aerogels were evaluated by the reaction of methanol oxidation, carried out in a fixed-bed flow reactor. Dimethyl ether was the most dominant product, and its selectivity was enhanced with addition of zinc species to titania matrix. Methyl formate was favorably observed over the catalyst of Zn/Ti=0.1 oxide, due to the presence of O2- deficiencies.
Electrical properties of the aerogels were analyzed by impedance spectroscopy. Impedance spectroscopy showed a depedance on the particle size and O2- deficiencies. They were evaluated in the media of air, and three contributions to have been resolved, including the contribution of bulk, the intergranular contact and the electrode contact. A correlation between particle structure, catalytic activity and electrical property is proposed in the study.
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