Abstract: Uniform ceria nanospheres with an average size of about 320 nm were prepared by a urea-hydrothermal route. The ceria nanospheres present a core-shell configur ation constructed by nanoparticles and nanosheets and predominantly expose the (111) planes. The ammonia bubble produced by urea hydrolysis plays a cruc ial role in determining the spherical structure. The redox properties and catalytic performance of CeO2 nanospheres rely on the unique stru cture closely.

Key words: ceria, nanosphere, redox, carbon monoxide oxidation