CeO2-supported LaMnO3 perovskite oxides were prepared to study their catalytic properties in the oxidation of NO to NO2. To prepare the catalyst and investigate the interaction between LaMnO3 and CeO2, two deposition methods were used. Extended X-ray absorption fine structure studies confirmed that perovskite oxide phases were formed on the CeO2 support. Moreover, X-ray photoelectron spectroscopy and temperature-programmed reduction with H-2 studies revealed that the reduction temperatures for perovskite oxides and CeO2 support decreased by the deposition followed by calcination at 650 A degrees C, and that the interaction between the LaMnO3 and CeO2 support can be controlled by changing the preparation method. The LaMnO3/CeO2 catalyst in which LaMnO3 was highly dispersed on CeO2 exhibited higher NO oxidation activity than either LaMnO3 or CeO2. The thermal stability of the LaMnO3/CeO2 catalyst was compared with that of alumina-supported LaMnO3 catalysts over 850-1050 A degrees C. [GRAPHICS] .