Low-Temperature Direct Synthesis of Nanoparticles of Fluorite-Type Ceria–Zirconia Solid Solutions by “Forced Cohydrolysis” at 100°C
✍ Scribed by Masanori Hirano; Toshio Miwa; Michio Inagaki
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 378 KB
- Volume
- 158
- Category
- Article
- ISSN
- 0022-4596
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✦ Synopsis
Nanometer-sized particles ranging from 2 to 3 nm of CeO 2 (ceria)+ZrO 2 (zirconia) solid solutions with cubic and/or tetragonal 6uorite-type structure in the wide composition range from 20 to 100 mol% CeO 2 , without a trace of monoclinic ZrO 2 phase, could be directly synthesized at low temperature of 1003C from acidic aqueous solutions of ZrOCl 2 and (NH 4 ) 2 Ce(NO 3 ) 6 by forced simultaneous hydrolysis, i.e., 99forced cohydrolysis.:: Analytical values of CeO 2 /ZrO 2 ratio in the as-precipitated solid solutions showed fairly good agreement with starting compositions in the solutions. The proceeding of the hydrolysis and formation rate of 6uorite-type solid solutions tended to slow down at near median composition. Any change in crystalline phase of as-precipitated solid solutions was not observed by powder X-ray di4ractometry after heat treatment in air below 10003C. Ceria+zirconia solid solutions with 6uorite structures containing large amount of ZrO 2 maintained high surface area after heat treatment at 10003C.