Synthesis of porous CuO-CeO2 nanospheres with an enhanced low-temperature CO oxidation activity.

CuO-CeO2 nanospheres with a porous structure were synthesized by an improved urea method involving first hydrothermal treatment to get Ce-Cu binary precursor and then the calcination of the precursor. The CuO-CeO2 nanospheres consist of spherical particles with diameters in the range of 300-400 nm. These nanospheres are actually composed of nanoparticles of ca. 10 nm, resulting in the formation of a mesoporous structure. Compared with conventional urea method, in which Ce-Cu binary precursor is commonly achieved in an oil bath at appropriate temperature, the Ce-Cu binary precursor obtained via the hydrothermal process could be more highly homogeneous and more highly interdispersed CuO-CeO2 thus was formed. In addition, the resulted porous CuO-CeO2 catalyst has a lower CO oxidation temperature of as low as 71 °C.