title: Catalytic evaluation of promoted CeO2-ZrO2 by transition, alkali, and alkaline-earth metal oxides for diesel soot oxidation.
abstract: Series of mixed metal oxides were synthesized by gel-combustion method and their catalytic activities for soot oxidation were investigated. The catalysts were M-Ce-Zr (M = Mn, Cu, Fe, K, Ba, Sr), and xK-20Mn-Ce-Zr (x = 0, 5, 10, 20), they were characterized by XRD, SEM, TPR and BET surface area techniques. The results of soot temperature programmed oxidation (TPO) in an O2 oxidizing atmosphere indicate that K-Ce-Zr has the highest catalytic activity for soot oxidation under loose contact condition, due to enhancement of the soot and catalyst contacts. On the other hand, under a tight contact condition, Mn-Ce-Zr and Cu-Ce-Zr nano-composites have high activities for soot oxidation and lower the soot TPO peak temperatures by about 280 and 270 degrees C, respectively, as compared to non-catalytic soot oxidation. Furthermore, the addition of up to 10 wt.% potassium oxides into Mn-Ce-Zr increases its catalytic activity and further reduces the soot TPO peak temperature by about 40 degrees C under loose contact condition.
authors.forename: Ali
authors.initials: A
authors.lastname: Alinezhadchamazketi
authors.forename: Abas Ali
authors.initials: AA
authors.lastname: Khodadadi
authors.forename: Yadollah
authors.initials: Y
authors.lastname: Mortazavi
authors.forename: Ahmad
authors.initials: A
authors.lastname: Nemati
mesh_terms: D000397:Air Pollution / Q000517:prevention & control*; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D010084:Oxidation-Reduction; D053260:Soot / Q000737:chemistry*; D013696:Temperature; D001335:Vehicle Emissions; D015040:Zirconium / Q000737:chemistry*
chemical_list: D053260:Soot; D001335:Vehicle Emissions; D002563:Cerium; C030583:ceric oxide; D015040:Zirconium; C028541:zirconium oxide