Ag supported on electrospun macro-structure CeO2 fibrous mats for diesel soot oxidation

Lee, Chanmin; Park, Joo Il; Shul, Yong Gun; Einaga, Hisahiro; Teraoka, Yasutake

doi:10.1016/j.apcatb.2015.03.008

Cited by 101 publications

(45 citation statements)

References 65 publications

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“…In common with our Ag-K/CZA catalyst, even the most active examples reported to date [12,27,30] operate within the temperature range associated with heavy-duty diesel vehicles, such as buses and trucks, for which very effective passive soot-control already exists. However, these catalysts could, in principle, be used to limit the amount and frequency of fuel injection on light-duty diesel vehicles that are fitted with actively regenerated particulate filters.…”

Section: Discussionmentioning

confidence: 97%

Using real particulate matter to evaluate combustion catalysts for direct regeneration of diesel soot filters

Ramdas

Nowicka

Jenkins

et al. 2015

Applied Catalysis B: Environmental

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a b s t r a c tThe particulate produced by internal combustion engines has a complex composition that includes a large proportion of porous soot within which condensed and adsorbed organic molecules are trapped. However, many studies of the catalytic combustion of particulate are based on the assumption that commercially produced carbon can be used as a reliable mimic of engine soot. Here we show that soot removed from a diesel particulate filter is rich in the polyaromatic molecules that are the precursors of the solid particulate. Through a combination of solvent extraction and evolved gas analysis, we have been able to track the release and transformation of these molecules in the absence and presence of combustion catalysts. Our results reveal that, although the rate of combustion of the elemental carbon in diesel soot is higher than that of graphite, deep oxidation of the polyaromatic molecules is a more demanding reaction. An active and stable Ag-K catalyst lowers the combustion temperature for elemental carbon by >200 • C, but has little effect on the condensed polyaromatic molecules. The addition of a secondary catalyst component, with aromatic-oxidation functionality is required to target these molecules. Although the combined catalyst would not enable a completely passive regeneration system for diesel passenger cars, it would improve the efficiency of existing active systems by reducing the amount of fuel-injection required for trap regeneration.

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Section: Discussionmentioning

confidence: 97%

Using real particulate matter to evaluate combustion catalysts for direct regeneration of diesel soot filters

Ramdas

Nowicka

Jenkins

et al. 2015

Applied Catalysis B: Environmental

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“…However, particulate matter (PM) from diesel engine emissions is gradually evolving to a serious threat to human health and the global environment [1,2,3,4]. Increasingly stringent emission regulations require solutions based on appropriate post-processing technology and improvements to the engine.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Oxidation of Soot on a Novel Active Ca-Co Dually-Doped Lanthanum Tin Pyrochlore Oxide

Wang

Cui

et al. 2018

Materials

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A novel active Ca-Co dually-doping pyrochlore oxide La2−xCaxSn2−yCoyO7 catalyst was synthesized by the sol-gel method for catalytic oxidation of soot particulates. The microstructure, atomic valence, reduction, and adsorption performance were investigated by X-ray powder diffraction (XRD), scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), H2-TPR (temperature-programmed reduction), and in situ diffuse reflection infrared Fourier transformed (DRIFTS) techniques. Temperature programmed oxidation (TPO) tests were performed with the mixture of soot-catalyst under tight contact conditions to evaluate the catalytic activity for soot combustion. Synergetic effect between Ca and Co improved the structure and redox properties of the solids, increased the surface oxygen vacancies, and provided a suitable electropositivity for oxide, directly resulting in the decreased ignition temperature for catalyzed soot oxidation as low as 317 °C. The presence of NO in O2 further promoted soot oxidation over the catalysts with the ignition temperature decreased to about 300 °C. The DRIFTS results reveal that decomposition of less stable surface nitrites may account for NO2 formation in the ignition period of soot combustion, which thus participate in the auxiliary combustion process.

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“…5,7 Diesel particulate lters (DPFs) combined with catalytic combustion of renewable technology is considered to be an efficient aer-treatment of soot oxidation; 3,5,[8][9][10] an effective catalyst with a lower light-off temperature is extremely important for DPF regeneration. 5,7,[9][10][11][12][13] Recently, CeO 2 has not only been reported to be used successfully in three-way catalysts, [14][15][16][17] but also as an excellent catalyst for soot combustion, 3,7,12,[18][19][20] because of its remarkable oxygen storage capacity (OSC) and redox property. Thus, CeO 2 -based catalysts have been investigated by several researchers, with respect to CeO 2 doped with noble (e.g., Ag, Pt and Pd), 17,21 transition (Cu, Mn, Co and Fe), [22][23][24] and lanthanide (La and Pr) metals.…”

Section: -6mentioning

confidence: 99%

Design structure for CePr mixed oxide catalysts in soot combustion

Fan

Zhu

et al. 2017

RSC Adv.

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Four CePr mixed oxides with different structures were designed and synthesized using a solid-phase grinding method: a uniform solid solution of Ce and Pr (CePr-NN), Pr 6 O 11 -coated CeO 2 (CePr-NO), CeO 2 -coated Pr 6 O 11 (CePr-ON), and particle packing of CeO 2 and Pr 6 O 11 (CePr-OO) were obtained, and characterized by XRD, H 2 -TPR, TEM and TG. The results show that CePr-NN exhibits the best low temperature catalytic activity among the CePr catalysts. CeO 2 is the major active phase on the surface of the CePr catalysts, and the use of Pr 6 O 11 as the framework maintains the thermal stability of the CePr composite oxide. Moreover, both the oxygen storage capacity and mobility of the active oxygen of the catalyst were improved with the incorporation of Pr into CeO 2 , resulting in a higher combustion rate. The "molten state" which appeared during the preparation when nitrate was used as the precursor, plays a significant role in the migration of Ce and Pr, and is the premise of forming different structures of solid solution or coating structure.

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Ag supported on electrospun macro-structure CeO2 fibrous mats for diesel soot oxidation

Cited by 101 publications

References 65 publications

Using real particulate matter to evaluate combustion catalysts for direct regeneration of diesel soot filters

Using real particulate matter to evaluate combustion catalysts for direct regeneration of diesel soot filters

Catalytic Oxidation of Soot on a Novel Active Ca-Co Dually-Doped Lanthanum Tin Pyrochlore Oxide

Design structure for CePr mixed oxide catalysts in soot combustion

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