The surfactant-assisted synthesis of CeO2 nanowires and their catalytic performance for CO oxidation

Synthesis of CeO2 assemblies through interaction with short-chain dicarboxylic acids under facile hydrothermal conditions

CeO₂ assemblies with various morphologies were synthesized via a facile hydrothermal method using short-chain dicarboxylic acids as the only added agent. It is demonstrated that the morphology of CeO₂ assemblies depends on the chain-length of the dicarboxylic acids. The reaction with propanedioic acid (PA) results in durian-like ceria assemblies. Comparatively, ethanedioic acid (EA) tends to precipitate with Ce³⁺ at the beginning, and then guides the formation of lamellar octahedral assemblies. The catalytic performance towards CO oxidation of the as-synthesized CeO₂ with different morphologies was investigated. Compared with lamellar octahedral assemblies, durian-like CeO₂ assemblies showed better catalytic performance, giving complete CO conversion at 350 °C, due to its properties of unique oxygen vacancies, loosely packed pore structure and larger specific surface area.

CeO₂ assemblies with various morphologies are hydrothermally synthesized using short-chain dicarboxylic acids as the only added agent.

Facile morphology control of 3D porous CeO2 for CO oxidation

3D porous CeO₂ with various morphologies was successfully synthesized via a facile precipitation using glycine as the soft bio-template. During the synthesis, it was demonstrated that the morphology of CeO₂ depended on the molar ratio of reactants. Furthermore, the catalytic performance towards CO oxidation of the as-synthesized CeO₂ with different morphologies was investigated. CeO₂ with a bowknot shape showed excellent catalytic performance, giving complete CO conversion at 370 °C, due to its properties of much higher oxygen vacancies, loosely packed pore structure and larger specific surface area.

Different morphologies of CeO₂ were obtained via a green and facial method, which realized CO complete conversion at 370 °C.

Ceria Nanotube Formed by Sacrificed Precursors Template through Oswald Ripening

Controllable preparation of ceria nanotube was realized by hydrothermal treatment of Ce(OH)CO₃ precursors. The gradually changing morphologies and microstructures of cerium oxide were characterized by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. A top-down path is illuminated to have an insight to the morphological transformation from nanorod to nanotube by adjusting the reaction time. The growth process is investigated by preparing a series of intermediate morphologies during the shape evolution of CeO₂nanostructure based on the scanning electron microscopy image observation. On the basis of the time-dependent experimental observation, the possible formation mechanism related to oriented attachment and Oswald ripening was proposed, which might afford some guidance for the synthesis of other inorganic nanotubes.