Abstract: Mesostuctured CeO₂ and CeO₂-ZrO₂ composite were synthesized via sol-gel method using cerium acetate and zirconium acetate as inorganic species, block copolymer P123 as surfactant, respectively. The obtained samples were characterized by XRD, N₂ adsorption-desorption, TEM, HRTEM, and SAED. Results show that the mesostrutured CeO₂ possesses crystalline framework with the average pore size of ca. 10nm. In particular, it’s revealed that the inorganic framework consists of highly oriented nanocrystals with the preferential orientation parallel to the channel arrays. In situ TEM observation equipped with the heating holder demonstrates that the mesostructured CeO₂ maintains perfect pore integrity up to 800℃ due to the confined growth tendency of oriented grains. Mesostructured CeO₂-ZrO₂ composite remains the similar framework structure when ZrO₂ molar ratio is less than 30%, however, it appears to transform to random oriented polycrystalline mesostructure when ZrO₂ molar ratio is higher than 30%.

Key words: highly preferential oriented, mesostructured CeO₂, in situ TEM, thermal stability