Highly Reducible Nanostructured CeO2 for CO Oxidation

Ceria in nanoscale with different morphologies, rod, tube and cube, were prepared through a hydrothermal process. The structure, morphology and textural properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and isothermal N2 adsorption-desorption. Ceria with different morphologies were evaluated as catalysts for CO oxidation. CeO2 nanorods showed superior activity to the others. When space velocity was 12,000 mL&middot
gcat&minus
1&middot
h&minus
1, the reaction temperature for 90% CO conversion (T90) was 228 &deg
C. The main reason for the high activity was the existence of large amounts of easily reducible oxygen species, with a reduction temperature of 217 &deg
C on the surface of CeO2 nanorods. Another cause was their relatively large surface area.