Catalytic combustion of soot on KNO3/ZrO2 catalysts.: Effect of potassium nitrate loading on activity

Co-KNO3-ZrO2 and Co-ZrO2 were prepared. The concentration effect of potassium nitrate on the activity was studied for the oxidation reaction of soot. Catalysts were characterized using the techniques BET, XRD, DSC, TPR, and SEM and the catalytic activity was measured in a microbalance. An important decrease of the combustion temperature of soot is observed in experiments carried out with zirconium oxide alone and also a significant enhancement of the catalytic combustion rate of soot on KNO3/ZrO2 catalysts. The activity increase can be attributed to the alkaline metal ion and also to the increase of the catalyst/soot contact by the molten potassium nitrate.