Fabrication Of Ceria And Ceria-based Oxides With3D Micro/Nano Structures And Their Catalytic Properties

The morphology of ceria and ceria-based nanomaterials has great effect on their catalytic performance. In order to design catalysts with better performance, ceria based nanomaterials with novel three-dimensinal (3D) micro/nano structures or with different chemical composition have been synthesized. This thesis focus on the precursor-based fabrication of ceria with3D hierarchical structures; synthesis of flower-like ceria a one-pot solution method; the fabrication of CeO2sub-micro spherical aggregates with controllable building blocks; preparation of Cu doped CeO2nanoparticles with high catalytic efficiency and the Cu2+assisted synthesis of hollow ceria particles.A. Fabrication of three Dimensional CeO2Hierarchical Structures by Precursor Templating.In this part, three dimensional mesoporous CeO2with hierarchical structures were synthesized through the thermal decomposition of cerium formate precursors, which were prepared by a solvothermal method. TEM, SEM, HRTEM were applied to characterize the precursors. Urchin-like Ce(HCOO)3precursors were prepared using dimethyl sulfoxide (DMSO) and ammonia solution (1M) as solvent and base source, respectively. While coral-like Ce(HCOO)3precursors were prepared using dimethyl formamide (DMF) and NH4HCO3as solvent and base source, respectively.B. A Mild Solution Strategy for the Synthesis of Mesoporous CeO2Nanoflowers Derived from Ce(HCOO)3.In this part, a facile and economical route based on an oxidation induced phase transformation in alcoholic solution was developed to prepare mesoporous CeO2nanoflowers. TEM, SEM, HRTEM and XRD were applied to characterize the products. Prompted by the mesoporous structure, high surface area and high pore volume, we speculate that these mesoporous CeO2flowers could be promising candidates for practical catalytic application.C. Monodisperse CeO2Sub-micro Spherical Aggregates with Controllable Building Blocks. In this part, monodisperse CeO2spherical have been successfully synthesized through a facile hydrothermal method. The structure and morphology of the samples were characterized by XRD, TEM, HRTEM and SEM. The building blocks (primary nanocrystals) of the spherical aggregates could be effectively tuned by adding different amount of urea. Finally, the formation mechanism of mechanism of CeO spherical aggregates was preliminarily discussed.D. Fabrication of Cu Doped Ceria Nanoparticles and Fabrication of Ceria Nanoparticles with Hollow Structures Induced by Cu2+In this part, Cu doped ceria nanospheres were successfully synthesized by a hydrothermal method. Because of the doping elements, the number of the oxygen vacancies has greatly increased, which highly improved the catalytic performance of the as-obtained. As comparison, the ceria nanoparticles with hollow structures were fabricated by adding a small amount of Cu2+. A small amount of Cu2+plays a pivotal role in constructing the hollow structures. Besides, the CO removal experiment...