Ce-Zr mixed oxides prepared in molten nitrates

Dispersed Ce0.75Zr0.25O2 and Zr0.84Ce0.16O2 cerium(IV)-zirconium(IV) mixed oxides were prepared by the flux method, from the reaction of hydrated Ce(NO3)3 and ZrOCl2 in molten NaNO3 at 450-500 °C in the presence of ammonium fluoride. The temperature and the stoichiometry of reactions were determined by mass spectrometry. Powder X-ray diffraction, specific surface area measurements (BET), and scanning electron microscopy were used to study the morphology and particle size distribution of the solid products. Preparation conditions were optimized to obtain pure oxides. Reaction at 550 °C in the presence of 1% wt. of ammonium fluoride gave the best result. © 2002 Elsevier Science B.V. All rights reserved.