CexZr1-xO2 solid solutions deposited over silica surface were investigated by X-ray diffraction (XRD), Raman spectroscopy (RS), and high-resolution transmission electron microscopy (HREM) techniques in order to understand the role of silica support and the temperature stability of these composite oxides. For the purpose of comparison, an unsupported CexZr1-xO2 was also synthesized and subjected to characterization by various techniques. The CexZr1-xO2/SiO2 (CZ/S) (1:1:2 mole ratio based on oxides) was synthesized by depositing CexZr1-xO2 solid solution over a colloidal SiO2 support by a deposition precipitation method and unsupported CexZr1-xO2 (CZ) (1: 1 mole ratio based on oxides) was prepared by a coprecipitation procedure, and the obtained catalysts were subjected to thermal treatments from 773 to 1073 K. The XRD measurements disclose the presence of cubic phases with the composition Ce0.75Zr0.25O2 and Ce0.6Zr0.4O2 in CZ samples, while CZ/S samples possess Ce0.75Zr0.25O2, Ce0.6Zr0.4O2, and Ce0.5Zr0.5O2 in different proportions. The crystallinity of these phases increased with increasing calcination temperature. The cell a parameter estimations indicate contraction of ceria lattice due to the incorporation of zirconium cations into the CeO2 unit cell. Raman measurements indicate the presence of oxygen vacancies, lattice defects, and displacement of oxygen ions from their normal lattice positions in both the series of samples. The HREM results reveal, in the case of CZ/S samples, a well-dispersed nanosized Ce-Zr-oxides over the surface of amorphous SiO2. The structural features of these crystals as determined by digital diffraction analysis of experimental images reveal that the Ce-Zr-oxides are mainly in the cubic geometry and exhibit high thermal stability. Oxygen storage capacity measurements by a thermogravimetric method reveal a substantial enhancement in the oxygen vacancy concentration of CZ/S sample over the unsupported CZ sample.