NOx-assisted soot oxidation based on Ag/MnOx-CeO2 mixed oxides

In previous studies, Ag/CeO2 catalyst showed the high activity on NOx-free soot oxidation. For additional improvement of oxidation activity, Mn was introduced in Ag/CeO2 and NOx-assisted soot oxidation was performed. NOx-assisted soot oxidation activities showed the large difference between the cata...

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Bibliographic Details
Published inApplied catalysis. A, General Vol. 627; p. 118396
Main Authors Lee, Eun Jun, Kim, Min June, Choung, Jin Woo, Kim, Chang Hwan, Lee, Kwan-Young
Format Journal Article
LanguageEnglish
Published Amsterdam Elsevier B.V 25.10.2021
Elsevier Science SA
Subjects
Adsorbed NOx
Adsorption
Ag/MnOx-CeO2
Catalysts
Cerium oxides
Low temperature
Mixed oxides
Nitrogen oxides
NO oxidation
Oxidation
Soot
Soot oxidation
Adsorbed NOx
NO oxidation
Ag/MnOx-CeO2
Soot oxidation
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Summary:In previous studies, Ag/CeO2 catalyst showed the high activity on NOx-free soot oxidation. For additional improvement of oxidation activity, Mn was introduced in Ag/CeO2 and NOx-assisted soot oxidation was performed. NOx-assisted soot oxidation activities showed the large difference between the catalysts. Especially, Ag/2MnOx-1CeO2 catalysts showed remarkably improved T20 at 349 °C compared with T20 of Ag/CeO2 at 464 °C (each T50 is 391 °C and 400 °C, and each Tmax is 514 °C and 509 °C). NO oxidation activity was increased as the mole ratio of Mn increased, while amount of NO adsorption was increased in Ag/MnOx-CeO2 mixed oxide compared to other catalysts. Especially, Ag/2MnOx-1CeO2 catalysts showed NO oxidation activity at low-temperature and NO desorption at appropriate temperature. As a result, it was confirmed that not only the NO oxidation activity but also the NOx adsorption characteristics are the most important factors in NOx-assisted soot oxidation. Accordingly, Ag/2MnOx-1CeO2 catalysts were proposed as optimal catalysts. [Display omitted] •Ag/MnOx-CeO2 catalysts were synthesized according to the mole ratio of Ce/Mn.•Ag/2MnOx-1CeO2 catalysts showed highest NOx-assisted soot oxidation activity compared to other catalysts.•NOx adsorbed on the catalyst was main factor in low-temperature soot oxidation.•NO was oxidized to NO2 by the Mn active site and the oxidized NO2 was adsorbed on the Ce surface site.
ISSN:0926-860X
1873-3875
DOI:10.1016/j.apcata.2021.118396