Thermal stability of ceria catalyst on alumina and its surface oxygen storage capacity

Ceria catalyst on alumina was studied by X-ray diffraction, electron microscopy and oxygen storage capacity (OSC) measurement. The particle size of CeO2, prepared by an impregnation method, was found to increase with elevated heat treatment (HT) temperatures, from 7 nm at 600 deg. C to 31 nm at 1200 deg. C for 3 h. The total OSC measured at 600 deg. C decreased with increasing HT temperature, however OSC per specific surface area of CeO2 was maintained for present 10-30 mol% ceria-doped catalyst. The relationship between OSC per Ce-mol and specific surface area of ceria suggested that amount of lattice oxygen site for OSC at 600 deg. C in CeO2 nanocrystals was 5μmol/m2, which was not dependent on particle size of CeO2