| By liquid phase precipitation method in this paper to explore different physical mechanism of the preparation of CeO2, research of this paper is divided into three parts:Ammonia-joint oxalate precipitation mechanism research of preparation of ultrafine CeO2. Of CeO2grain size distribution, apparent density, tap density, characterizing the morphology, liquidity, dispersion, specific surface area. And by using X-ray diffraction (XRD), Fourier infrared diffraction, the Ce3+/Ce4+test means such as to determine the ammonia conversion mechanism of the precipitation to oxalic acid precipitation: ammonia after precipitation, Ce(OH)3was oxidized to Ce(OH)4, addition of increase gradually with the oxalic acid, oxalic acid, have the effect of reducing the Ce4+ion reduction into Ce3+, to generate Ce2(C2O4)310H2O.By oxalic acid precipitation on the research of the preparation of large particles CeO2take amatsu loading density. Research in the process of oxalic acid precipitation for the amount of ammonium nitrate Zate potential of precipitation particles and the influence of the dispersion. Using elemental analysis, XRD, thermal analysis, infrared testing techniques to determine the composition and structure of the precursor for Ce2(C2O4)3.The ammonia-cerium ammonium bicarbonate precipitation preparation of high specific surface area of rare earth compounds. Through the study of ammonia-process for the amount of ammonium nitrate, ammonium bicarbonate coprecipitation of different surfactant addition amount on the precipitation particles Zate potential impact, found that adding ammonium nitrate than without ammonium nitrate precipitation the whole system more stable, add the amount of ammonium nitrate and the molar ratio of cerium to1it is concluded that the specific surface area, the largest. Using elemental analysis, XRD, thermal analysis, infrared testing technology to determine the composition and structure of the precursor for Ce2(CO3)2O H2O. |
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