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In this study, Al 2 O 3 , ZrO 2 , La 2 O 3 , and Y 2 O 3 were separately introduced into Pt/CeO 2 -MnO x catalyst to improve the thermal stability of catalysts and obtain a better soot and NO oxidation activity after thermal treatment. CeO 2 -MnO x -RO x (R = Al, La, Y, or Zr) mixed oxides were prepared by a co-precipitation method. The catalysts were characterized by XRD, BET, H 2 -TPR, CO chemisorption, XPS, TG analysis, soot–TPO, and NO–TPO. It is found that the introduction of R n + into CeO 2 -MnO x markedly increases the thermal stability of the catalysts for soot and NO oxidation, remaining a better catalytic oxidation activity. On the one hand, after high-temperature aging, for the modified catalyst Pt/CeMnRO x , the ignition temperature of soot oxidation ( T i ) and maximal soot oxidation rate temperature ( T m ) increase by 30–50 °C and 4–32 °C, respectively, whereas Al 3 + -modified catalyst shows the best thermal stability. On the other hand, due to a key role of NO 2 as a strong oxidizing agent in soot oxidation process, the NO oxidation activity is often considered as an important aspect. This work shows that R n + -modified catalysts display a better stability on NO oxidation activity after aging. Some factors leading to the thermal deactivation of catalysts are also discussed in this paper. [ABSTRACT FROM AUTHOR]

This paper addresses the possibility that dielectric-barrier-discharge (DBD) can provide in situ fuel processing to manipulate methane diffusion flame, and this technology may be extended to other higher-order hydrocarbon fuels. In this work, an in situ fuel processing system, by coupling a DBD generator to the fuel nozzle, was developed to examine the chemical effect of the DBD on enhanced ignition and inhibited extinction of a CH 4 /O 2 /Ar counterflow diffusion flame. Experimental results show that 25 kHz plasma reduces the ignition temperature by approximately 180 K, and extends the extinction limit by approximately 20% with a moderate stretch rate. DBD sustained in the fuel stream is expected to perform as a pool of radicals and active molecules to promote combustion, which was verified by the diagnosis of several key intermediate species. In situ planar laser-induced fluorescence (PLIF) technique mapped the profile of CH radical, and gas chromatograph measured some stable species, such as hydrogen and higher order hydrocarbons. Hydrogen is more reactive fuel; therefore, this paper gives further insight into hydrogen-enriched ignition by CHEMKIN-PRO, and it is found that the acceleration is approached through more efficient generation of H radical. • The dielectric-barrier-discharge (DBD) was used as in situ fuel processing technology and applied to a counterflow burner. • The plasma can decrease the ignition temperature by approximately 180 K and extend the extinction limit by approximately 20% under certain conditions. • The PLIF technique was employed to determine CH radical and verify in situ plasma effect, while a gas chromatograph was used to measure H 2 produced by plasma. • The kinetics of hydrogen enriched ignition were analyzed using CHEMKIN-PRO. [ABSTRACT FROM AUTHOR]