Conversion of halon 1211 (CBrClF2) over supported Pd catalysts

Hai Yu, Eric M. Kennedy, Azhar Uddin, Adesoji A. Adesina, Bogdan Z. Dlugogorski

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Conversion of halon 1211 has been studied over γ-Al2O 3 and supported 0.5% Pd catalysts (Pd/Al2O3, Pd/fluorinated Al2O3, Pd/AlF3, Pd/Al 2O3 pretreated with CH4 and CHClF2). The experiments were performed in the temperature range of 443-523 K, in a tubular alumina reactor. The temperature of the reactor was maintained uniformly by a three zone furnace. The reaction products were quantified with a micro gas Chromatograph and identified with a gas chromatograph-mass spectrometer. The catalysts were characterised with XRD diffractometry and the content of halogen on the catalysts was determined with an ion Chromatograph. The measurements were presented in terms of the conversion of halon 1211 and product selectivity, as functions of catalyst type, catalyst time on stream and composition of inlet gases. Transformation of Pd to Pd carbide is observed in the CH4 treated Pd/Al2O3 but not in the CHClF2 treated Pd/Al2O3 in which case Al2O3 was partially fluorinated. In the absence of hydrogen, the conversion of halon 1211 over Al2O3 and Pd/Al2O3 gives a similar product profile and the reactions follow a heterogeneous halogen exchange reaction pathway, which takes place on the positively charged aluminum ions. Introduction of hydrogen has no apparent effect on either halon 1211 conversion level or the product profile during the conversion of halon 1211 over Al2O3. Over supported Pd catalysts, major products are hydrogenated species which include CH2F2, CH4, C2H6, C3H8, CH3Br and CHF3. The most striking feature of the hydrodehalogenation reactions is the increasing CH2F2 selectivity with time on stream, especially on Pd/Al2O3 and the CH4 treated Pd/Al2O3. The changing selectivity during the catalytic hydrodehalogenation reactions is mainly ascribed to the interaction of support with Pd.

Original languageEnglish
Pages (from-to)205-215
Number of pages11
JournalCatalysis Today
Volume97
Issue number2-3 SPEC. ISS.
DOIs
Publication statusPublished - Oct 27 2004
Externally publishedYes

Fingerprint

Halon
Catalyst supports
Catalysts
Halogens
Gases
Hydrogen
Ions
Catalyst selectivity
Aluminum Oxide
Mass spectrometers
Aluminum
Reaction products
Carbides
Furnaces
Alumina
bromochlorodifluoromethane
Temperature
Chemical analysis

Keywords

  • γ-AlO
  • AlF
  • Catalytic hydrodehalogenation
  • CBrClF
  • CFC
  • CHF
  • Fluorinated alumina
  • Halon
  • Palladium

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

Yu, H., Kennedy, E. M., Uddin, A., Adesina, A. A., & Dlugogorski, B. Z. (2004). Conversion of halon 1211 (CBrClF2) over supported Pd catalysts. Catalysis Today, 97(2-3 SPEC. ISS.), 205-215. https://doi.org/10.1016/j.cattod.2004.03.069

Conversion of halon 1211 (CBrClF2) over supported Pd catalysts. / Yu, Hai; Kennedy, Eric M.; Uddin, Azhar; Adesina, Adesoji A.; Dlugogorski, Bogdan Z.

In: Catalysis Today, Vol. 97, No. 2-3 SPEC. ISS., 27.10.2004, p. 205-215.

Research output: Contribution to journalArticle

Yu, H, Kennedy, EM, Uddin, A, Adesina, AA & Dlugogorski, BZ 2004, 'Conversion of halon 1211 (CBrClF2) over supported Pd catalysts', Catalysis Today, vol. 97, no. 2-3 SPEC. ISS., pp. 205-215. https://doi.org/10.1016/j.cattod.2004.03.069
Yu H, Kennedy EM, Uddin A, Adesina AA, Dlugogorski BZ. Conversion of halon 1211 (CBrClF2) over supported Pd catalysts. Catalysis Today. 2004 Oct 27;97(2-3 SPEC. ISS.):205-215. https://doi.org/10.1016/j.cattod.2004.03.069
Yu, Hai ; Kennedy, Eric M. ; Uddin, Azhar ; Adesina, Adesoji A. ; Dlugogorski, Bogdan Z. / Conversion of halon 1211 (CBrClF2) over supported Pd catalysts. In: Catalysis Today. 2004 ; Vol. 97, No. 2-3 SPEC. ISS. pp. 205-215.
@article{4de7bfc714aa42069d6a359ca20de16c,
title = "Conversion of halon 1211 (CBrClF2) over supported Pd catalysts",
abstract = "Conversion of halon 1211 has been studied over γ-Al2O 3 and supported 0.5{\%} Pd catalysts (Pd/Al2O3, Pd/fluorinated Al2O3, Pd/AlF3, Pd/Al 2O3 pretreated with CH4 and CHClF2). The experiments were performed in the temperature range of 443-523 K, in a tubular alumina reactor. The temperature of the reactor was maintained uniformly by a three zone furnace. The reaction products were quantified with a micro gas Chromatograph and identified with a gas chromatograph-mass spectrometer. The catalysts were characterised with XRD diffractometry and the content of halogen on the catalysts was determined with an ion Chromatograph. The measurements were presented in terms of the conversion of halon 1211 and product selectivity, as functions of catalyst type, catalyst time on stream and composition of inlet gases. Transformation of Pd to Pd carbide is observed in the CH4 treated Pd/Al2O3 but not in the CHClF2 treated Pd/Al2O3 in which case Al2O3 was partially fluorinated. In the absence of hydrogen, the conversion of halon 1211 over Al2O3 and Pd/Al2O3 gives a similar product profile and the reactions follow a heterogeneous halogen exchange reaction pathway, which takes place on the positively charged aluminum ions. Introduction of hydrogen has no apparent effect on either halon 1211 conversion level or the product profile during the conversion of halon 1211 over Al2O3. Over supported Pd catalysts, major products are hydrogenated species which include CH2F2, CH4, C2H6, C3H8, CH3Br and CHF3. The most striking feature of the hydrodehalogenation reactions is the increasing CH2F2 selectivity with time on stream, especially on Pd/Al2O3 and the CH4 treated Pd/Al2O3. The changing selectivity during the catalytic hydrodehalogenation reactions is mainly ascribed to the interaction of support with Pd.",
keywords = "γ-AlO, AlF, Catalytic hydrodehalogenation, CBrClF, CFC, CHF, Fluorinated alumina, Halon, Palladium",
author = "Hai Yu and Kennedy, {Eric M.} and Azhar Uddin and Adesina, {Adesoji A.} and Dlugogorski, {Bogdan Z.}",
year = "2004",
month = "10",
day = "27",
doi = "10.1016/j.cattod.2004.03.069",
language = "English",
volume = "97",
pages = "205--215",
journal = "Catalysis Today",
issn = "0920-5861",
publisher = "Elsevier",
number = "2-3 SPEC. ISS.",

}

TY - JOUR

T1 - Conversion of halon 1211 (CBrClF2) over supported Pd catalysts

AU - Yu, Hai

AU - Kennedy, Eric M.

AU - Uddin, Azhar

AU - Adesina, Adesoji A.

AU - Dlugogorski, Bogdan Z.

PY - 2004/10/27

Y1 - 2004/10/27

N2 - Conversion of halon 1211 has been studied over γ-Al2O 3 and supported 0.5% Pd catalysts (Pd/Al2O3, Pd/fluorinated Al2O3, Pd/AlF3, Pd/Al 2O3 pretreated with CH4 and CHClF2). The experiments were performed in the temperature range of 443-523 K, in a tubular alumina reactor. The temperature of the reactor was maintained uniformly by a three zone furnace. The reaction products were quantified with a micro gas Chromatograph and identified with a gas chromatograph-mass spectrometer. The catalysts were characterised with XRD diffractometry and the content of halogen on the catalysts was determined with an ion Chromatograph. The measurements were presented in terms of the conversion of halon 1211 and product selectivity, as functions of catalyst type, catalyst time on stream and composition of inlet gases. Transformation of Pd to Pd carbide is observed in the CH4 treated Pd/Al2O3 but not in the CHClF2 treated Pd/Al2O3 in which case Al2O3 was partially fluorinated. In the absence of hydrogen, the conversion of halon 1211 over Al2O3 and Pd/Al2O3 gives a similar product profile and the reactions follow a heterogeneous halogen exchange reaction pathway, which takes place on the positively charged aluminum ions. Introduction of hydrogen has no apparent effect on either halon 1211 conversion level or the product profile during the conversion of halon 1211 over Al2O3. Over supported Pd catalysts, major products are hydrogenated species which include CH2F2, CH4, C2H6, C3H8, CH3Br and CHF3. The most striking feature of the hydrodehalogenation reactions is the increasing CH2F2 selectivity with time on stream, especially on Pd/Al2O3 and the CH4 treated Pd/Al2O3. The changing selectivity during the catalytic hydrodehalogenation reactions is mainly ascribed to the interaction of support with Pd.

AB - Conversion of halon 1211 has been studied over γ-Al2O 3 and supported 0.5% Pd catalysts (Pd/Al2O3, Pd/fluorinated Al2O3, Pd/AlF3, Pd/Al 2O3 pretreated with CH4 and CHClF2). The experiments were performed in the temperature range of 443-523 K, in a tubular alumina reactor. The temperature of the reactor was maintained uniformly by a three zone furnace. The reaction products were quantified with a micro gas Chromatograph and identified with a gas chromatograph-mass spectrometer. The catalysts were characterised with XRD diffractometry and the content of halogen on the catalysts was determined with an ion Chromatograph. The measurements were presented in terms of the conversion of halon 1211 and product selectivity, as functions of catalyst type, catalyst time on stream and composition of inlet gases. Transformation of Pd to Pd carbide is observed in the CH4 treated Pd/Al2O3 but not in the CHClF2 treated Pd/Al2O3 in which case Al2O3 was partially fluorinated. In the absence of hydrogen, the conversion of halon 1211 over Al2O3 and Pd/Al2O3 gives a similar product profile and the reactions follow a heterogeneous halogen exchange reaction pathway, which takes place on the positively charged aluminum ions. Introduction of hydrogen has no apparent effect on either halon 1211 conversion level or the product profile during the conversion of halon 1211 over Al2O3. Over supported Pd catalysts, major products are hydrogenated species which include CH2F2, CH4, C2H6, C3H8, CH3Br and CHF3. The most striking feature of the hydrodehalogenation reactions is the increasing CH2F2 selectivity with time on stream, especially on Pd/Al2O3 and the CH4 treated Pd/Al2O3. The changing selectivity during the catalytic hydrodehalogenation reactions is mainly ascribed to the interaction of support with Pd.

KW - γ-AlO

KW - AlF

KW - Catalytic hydrodehalogenation

KW - CBrClF

KW - CFC

KW - CHF

KW - Fluorinated alumina

KW - Halon

KW - Palladium

UR - http://www.scopus.com/inward/record.url?scp=5644293333&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=5644293333&partnerID=8YFLogxK

U2 - 10.1016/j.cattod.2004.03.069

DO - 10.1016/j.cattod.2004.03.069

M3 - Article

VL - 97

SP - 205

EP - 215

JO - Catalysis Today

JF - Catalysis Today

SN - 0920-5861

IS - 2-3 SPEC. ISS.

ER -