Low-temperature catalytic oxidation of NO over Mn-Ce-Ox catalyst

A series of manganese-cerium oxide catalysts were prepared by different methods and used for low-temperature catalytic oxidation of NO in the presence of excess O-2. Their surface properties were evaluated by means of BET and were characterized by using scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The activity test of Mn-Ce-O-x catalysts showed that addition of Ce enhanced the activities of NO oxidation. The most active catalysts with a molar Ce/(Mn+Ce) ratio of 0.3 were prepared by co-precipitation method. The results showed that NO conversion reached 60% at 150 degrees C with a high space velocity of 50902 h(-1). The effect of doping different rare earth oxides was also investigated and the addition of small amount of Ce not only increased the surface area of MnOx but also enhanced the dispersion of Mn species in the catalyst shown by BET, SEM and XRD.