Catalytic Combustion of Diesel Soot on Co−Sr−K Catalysts

Abstract

The catalytic activities of Co3O4, Sr(NO3)2, Co−Sr, and Co−Sr−K catalysts were studied, and the effect of the contact mode on the soot onset ignition temperature and soot oxidation rate was also discussed. All the catalysts were characterized by X-ray diffraction and thermogravimetry/differential scanning calorimetry. The catalytic activities were evaluated by a soot oxidation reaction using the temperature-programmed reaction system. The soot onset ignition temperature is 370 °C for Co−Sr catalysts with molar ratios of 1:1 and 2:1, which is the same as that of pure Co3O4. The Co−Sr catalysts containing KNO3 can greatly lower the soot onset ignition temperature. The catalytic activity of pure Co3O4 and Sr(NO3)2 is affected by catalysts−soot contact intensity, which has nearly no effect on the soot onset ignition temperature and soot oxidation rate for Co−Sr catalysts with appropriate ratios. The cooperation of Co3O4 and Sr(NO3)2 can accelerate the soot oxidation rate and reduce the effect of the soot−cata...