Synthesis of CeO2-ZrO2 Solid Solutions by Hydrolysis.

(1) Direct precipitation of ceria-zirconia solid solutions containing more than 66.3mol% ZrO2 was successfully achieved under hydrothermal conditions by co-hydrolysis of acidic aqueous solutions of ZrOCl2 and Ce(SO4)2⋅2(NH4)2SO4.(2) The morphology of ceria-zirconia solid solutions obtained was spherical to some extent due to agglomeration of nanometer-sized primary particles.(3) The crystallite size, lattice parameter, and lattice strain of ceria-zirconia solid solutions also changed depending on the composition in the system. The morphology and crystalline phase of the precipitates were greatly influenced by the nature of anion constituent of cerium and zirconium salts.