Oxygen desorption properties of Pr6O11 doped with Bi and Ce for low temperature particulate matter oxidation

Koichiro Harada, Tetsuya Oishi, Seiji Hamamoto, Takuma Kawasaki, Tatsumi Ishihara

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In this study, the effect of doping elements on the ignition temperature of soot oxidation over Pr-based oxides and the reaction mechanism was investigated. When Pr6O11 was doped with Bi and various elements that have the potential to decrease the ignition temperature, Ce doping was observed to provide the lowest ignition temperature. Isotopic exchange experiments were then performed to characterize lattice oxygen desorption via the oxygen exchange reaction, which is closely related to soot oxidation activity. While the rate of isotopic exchange was not improved by doping Pr6O11 with Bi and Ce, both the apparent activation energy and frequency factor identified from the Arrhenius plot of the exchange rate constants were lowered. The lower oxygen exchange rate for Bi- and Ce-doped Pr6O11 appears to be due to a smaller number of active sites being involved in oxygen exchange for the doped compound compared with that for pure Pr6O11. In contrast, when the doped catalyst was mixed with carbon, carbon oxidation by lattice oxygen was promoted by substitution with Bi and Ce. Thus, the presence of carbon was observed to accelerate desorption of active lattice oxygen via the oxygen exchange reaction for Bi- and Ce-doped Pr6O11. The decrease in the carbon oxidation temperature by Bi and Ce appears to be assigned to the oxygen exchange promoted by oxygen vacancy formation by reduction with carbon, which acts as a reducing agent.

Original languageEnglish
Pages (from-to)223-230
Number of pages8
JournalApplied Catalysis A: General
Volume492
DOIs
Publication statusPublished - Feb 25 2015

Fingerprint

Particulate Matter
Desorption
Oxygen
Oxidation
Carbon
Soot
Ignition
Temperature
Doping (additives)
Ion exchange
Arrhenius plots
Reducing Agents
Reducing agents
Oxygen vacancies
Chemical elements
Oxides
Rate constants
Substitution reactions
Thermodynamic properties
Activation energy

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Process Chemistry and Technology

Cite this

Oxygen desorption properties of Pr6O11 doped with Bi and Ce for low temperature particulate matter oxidation. / Harada, Koichiro; Oishi, Tetsuya; Hamamoto, Seiji; Kawasaki, Takuma; Ishihara, Tatsumi.

In: Applied Catalysis A: General, Vol. 492, 25.02.2015, p. 223-230.

Research output: Contribution to journalArticle

Harada, Koichiro ; Oishi, Tetsuya ; Hamamoto, Seiji ; Kawasaki, Takuma ; Ishihara, Tatsumi. / Oxygen desorption properties of Pr6O11 doped with Bi and Ce for low temperature particulate matter oxidation. In: Applied Catalysis A: General. 2015 ; Vol. 492. pp. 223-230.
@article{58e3d8f1a1104c2f8d5a7a1fcf1f7dc4,
title = "Oxygen desorption properties of Pr6O11 doped with Bi and Ce for low temperature particulate matter oxidation",
abstract = "In this study, the effect of doping elements on the ignition temperature of soot oxidation over Pr-based oxides and the reaction mechanism was investigated. When Pr6O11 was doped with Bi and various elements that have the potential to decrease the ignition temperature, Ce doping was observed to provide the lowest ignition temperature. Isotopic exchange experiments were then performed to characterize lattice oxygen desorption via the oxygen exchange reaction, which is closely related to soot oxidation activity. While the rate of isotopic exchange was not improved by doping Pr6O11 with Bi and Ce, both the apparent activation energy and frequency factor identified from the Arrhenius plot of the exchange rate constants were lowered. The lower oxygen exchange rate for Bi- and Ce-doped Pr6O11 appears to be due to a smaller number of active sites being involved in oxygen exchange for the doped compound compared with that for pure Pr6O11. In contrast, when the doped catalyst was mixed with carbon, carbon oxidation by lattice oxygen was promoted by substitution with Bi and Ce. Thus, the presence of carbon was observed to accelerate desorption of active lattice oxygen via the oxygen exchange reaction for Bi- and Ce-doped Pr6O11. The decrease in the carbon oxidation temperature by Bi and Ce appears to be assigned to the oxygen exchange promoted by oxygen vacancy formation by reduction with carbon, which acts as a reducing agent.",
author = "Koichiro Harada and Tetsuya Oishi and Seiji Hamamoto and Takuma Kawasaki and Tatsumi Ishihara",
year = "2015",
month = "2",
day = "25",
doi = "10.1016/j.apcata.2014.12.036",
language = "English",
volume = "492",
pages = "223--230",
journal = "Applied Catalysis A: General",
issn = "0926-860X",
publisher = "Elsevier",

}

TY - JOUR

T1 - Oxygen desorption properties of Pr6O11 doped with Bi and Ce for low temperature particulate matter oxidation

AU - Harada, Koichiro

AU - Oishi, Tetsuya

AU - Hamamoto, Seiji

AU - Kawasaki, Takuma

AU - Ishihara, Tatsumi

PY - 2015/2/25

Y1 - 2015/2/25

N2 - In this study, the effect of doping elements on the ignition temperature of soot oxidation over Pr-based oxides and the reaction mechanism was investigated. When Pr6O11 was doped with Bi and various elements that have the potential to decrease the ignition temperature, Ce doping was observed to provide the lowest ignition temperature. Isotopic exchange experiments were then performed to characterize lattice oxygen desorption via the oxygen exchange reaction, which is closely related to soot oxidation activity. While the rate of isotopic exchange was not improved by doping Pr6O11 with Bi and Ce, both the apparent activation energy and frequency factor identified from the Arrhenius plot of the exchange rate constants were lowered. The lower oxygen exchange rate for Bi- and Ce-doped Pr6O11 appears to be due to a smaller number of active sites being involved in oxygen exchange for the doped compound compared with that for pure Pr6O11. In contrast, when the doped catalyst was mixed with carbon, carbon oxidation by lattice oxygen was promoted by substitution with Bi and Ce. Thus, the presence of carbon was observed to accelerate desorption of active lattice oxygen via the oxygen exchange reaction for Bi- and Ce-doped Pr6O11. The decrease in the carbon oxidation temperature by Bi and Ce appears to be assigned to the oxygen exchange promoted by oxygen vacancy formation by reduction with carbon, which acts as a reducing agent.

AB - In this study, the effect of doping elements on the ignition temperature of soot oxidation over Pr-based oxides and the reaction mechanism was investigated. When Pr6O11 was doped with Bi and various elements that have the potential to decrease the ignition temperature, Ce doping was observed to provide the lowest ignition temperature. Isotopic exchange experiments were then performed to characterize lattice oxygen desorption via the oxygen exchange reaction, which is closely related to soot oxidation activity. While the rate of isotopic exchange was not improved by doping Pr6O11 with Bi and Ce, both the apparent activation energy and frequency factor identified from the Arrhenius plot of the exchange rate constants were lowered. The lower oxygen exchange rate for Bi- and Ce-doped Pr6O11 appears to be due to a smaller number of active sites being involved in oxygen exchange for the doped compound compared with that for pure Pr6O11. In contrast, when the doped catalyst was mixed with carbon, carbon oxidation by lattice oxygen was promoted by substitution with Bi and Ce. Thus, the presence of carbon was observed to accelerate desorption of active lattice oxygen via the oxygen exchange reaction for Bi- and Ce-doped Pr6O11. The decrease in the carbon oxidation temperature by Bi and Ce appears to be assigned to the oxygen exchange promoted by oxygen vacancy formation by reduction with carbon, which acts as a reducing agent.

UR - http://www.scopus.com/inward/record.url?scp=84921668509&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84921668509&partnerID=8YFLogxK

U2 - 10.1016/j.apcata.2014.12.036

DO - 10.1016/j.apcata.2014.12.036

M3 - Article

AN - SCOPUS:84921668509

VL - 492

SP - 223

EP - 230

JO - Applied Catalysis A: General

JF - Applied Catalysis A: General

SN - 0926-860X

ER -