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TG and DTG curves of diesel particle shift to the low temperature region with the increase of Mn doping into CeO2system, which indicates that the particle ignition combustion temperature decreases.

As an effective method, diesel particulate filter (DPF) technology has a great contribution in reducing soot emissions from diesel engines. To achieve passive regeneration of DPF at low temperatures, K-doped ce 0.5 Mn 0.5 o 2 catalysts were synthesized using sol-gel method. The effect of K-doped catalysts-K z-ce 0.5 Mn 0.5 o 2-on the oxidation of soot had been studied by thermogravimetric analysis, and the corresponding catalytic properties were evaluated based on X-ray diffraction (XRD), hydrogen temperature programmed reduction (H 2-TPR), O 2 temperature programmed desorption (O 2-TPD) Raman spectroscopy (Raman), Brunauer-Emmett-Teller (BET) and Fourier-Transform-Infrared (FTIR). The results showed that K doping facilitated the oxidation of diesel particulate matter, which was indicated by the entire mass loss curve shifting to lower temperatures. K 0.2-ce 0.5 Mn 0.5 o 2 showed the best performance among the series of K-doped catalysts. Compared with the findings for Ce 0.5 Mn 0.5 o 2 , the ignition temperature of soot oxidation (T i) had been lowered by 28 ℃, and the maximum peak combustion temperature (T m) of the dry soot decreased by 61 °C. Furthermore, compared with the ce 0.5 Mn 0.5 o 2-catalyzed reaction, K doping led to a lower activation energy and significantly improved pre-exponential factor. The minimum reaction activation energy of 27.46 kJ/mol was exhibited by K 0.2-ce 0.5 Mn 0.5 o 2. Diesel vehicles are currently attracting interest owing to their distinctive characteristics of superior power performance and fuel economic properties 1-3 while the pollutants contained in diesel exhaust gas, particularly soot, pose hazards to human's living environment and become one of the source of greenhouse gas which leads to global warming. Therefore, finding proper ways to cut down soot emissions from diesel engines become one of the researching hotpots in the study progress of diesel vehicles, that' why many researchers studied diesel particulate filters (DPF), an effective methods of lowering soot emissions by passive regeneration by chemical catalysis and improving the temperature of the diesel exhaust which is sufficient for soot to burn out. Hence, selecting a suitable catalyst is the key challenge for regeneration 4-8. It is well known that the utilization rate of rare earth resources is low, despite their abundance. CeO 2 plays an important role in three-way catalysts owing to its excellent oxygen storage and release properties 9. Generally, CeO 2 performs as an oxygen buffer to store excess oxygen quickly as the oxygen concentration in the exhaust gas is increasing to higher level, and releasing oxygen promptly at low oxygen concentrations 10-12. In addition, CeO 2 is a promising noble metal substitute for improving the anti-poisoning performance and high temperature durability of catalysts 13,14. The technology of Ce-based catalysts is still constantly improving after decades of development. The unique chemical and physical properties of rare earth-based catalysts present due to their electronic ener...

Nano-CeO2 catalysts simultaneously reduce diesel soot and nitric oxide on a catalytic activity evaluation platform.

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