Catalytic Combustion of Soot over the Highly Active (La0.9K0.1CoO3)x/nmCeO2 Catalysts

The highly active (La0.9K0.1CoO3)(x)/nmCeO(2) catalysts consisting of comparably sized La0.9K0.1CoO3 active component and CeO2 support nanoparticle were studied on the catalytic combustion of soot by temperature-programmed oxidation (TPO) technique. The properties of oxygen species and the redox performances of catalysts were investigated by the method of O-2-TPD and H-2-TPR. During TPO process, all supported oxide catalysts showed lower T than the corresponding nanometer CeO2 support or pure La0.9K0.1CoO3 perovskite. The best catalytic activity was obtained over (La0.9K0.1CoO3)(2)/nmCeO(2) catalyst (T-m = 354 degrees C), and its catalytic activity for the combustion of soot is as good as supported Pt catalysts. During the catalytic combustion of soot, the surface alpha oxygen species should play an important role. The formation of surface oxygen-containing complexes (SOC) may be one of the key intermediate species according to the results of in situ DRIFT, and NO2 released by surface nitrate species remarkably promote the soot oxidation.