Role of excited CF3CFHO radicals in the atmospheric chemistry of HFC-134a

T. J. Wallington; M. D. Hurley; J. M. Fracheboud; J. J. Orlando; G. S. Tyndall; J. Sehested; T. E. Møgelberg; O. J. Nielsen

Role of excited CF₃CFHO radicals in the atmospheric chemistry of HFC-134a

T. J. Wallington^*, M. D. Hurley, J. M. Fracheboud, J. J. Orlando, G. S. Tyndall, J. Sehested, T. E. Møgelberg, O. J. Nielsen

^*Corresponding author for this work

129 Citations (Scopus)

Abstract

The atmospheric degradation of HFC-134a (CF₃CFH₂) proceeds via the formation of CF₃CFHO radicals. Long path length FTIR environmental chamber techniques were used to study the atmospheric fate of CF₃-CFHO radicals. Two competing reaction pathways were identified for CF₃CFHO radicals: reaction with O₂, CF₃CFHO + O₂ → CF₃C(O)F + HO₂, and decomposition via C-C bond scission, CF₃CFHO + M → CF₃ + HC(O)F + M. CF₃CFHO radicals were produced by two different reactions: either via the self-reaction of CF₃CFHO₂ radicals or via the CF₃CFHO₂ + NO reaction. It was found that decomposition was much more important when CF₃CFHO radicals were produced via the CF₃CFHO₂ + NO reaction than when they were produced via the self-reaction of CF₃CFHO₂ radicals. We ascribe this observation to the formation of vibrationally excited CF₃CFHO* radicals in the CF₃CFHO₂ + NO reaction. Rapid decomposition of CF₃-CFHO* radicals limits the formation of CF₃C(O)F and hence CF₃COOH in the atmospheric degradation of HFC-134a. We estimate that the CF₃COOH yield from atmospheric oxidation of HFC-134a is 7-20%. Vibrationally excited alkoxy radicals may play an important role in the atmospheric chemistry of other organic compounds.

Original language	English
Journal	Journal of Physical Chemistry
Volume	100
Issue number	46
Pages (from-to)	18116-18122
Number of pages	7
ISSN	0022-3654
Publication status	Published - 14 Nov 1996

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@article{1782228be4cb401ba2d9186736ec951c,

title = "Role of excited CF3CFHO radicals in the atmospheric chemistry of HFC-134a",

abstract = "The atmospheric degradation of HFC-134a (CF3CFH2) proceeds via the formation of CF3CFHO radicals. Long path length FTIR environmental chamber techniques were used to study the atmospheric fate of CF3-CFHO radicals. Two competing reaction pathways were identified for CF3CFHO radicals: reaction with O2, CF3CFHO + O2 → CF3C(O)F + HO2, and decomposition via C-C bond scission, CF3CFHO + M → CF3 + HC(O)F + M. CF3CFHO radicals were produced by two different reactions: either via the self-reaction of CF3CFHO2 radicals or via the CF3CFHO2 + NO reaction. It was found that decomposition was much more important when CF3CFHO radicals were produced via the CF3CFHO2 + NO reaction than when they were produced via the self-reaction of CF3CFHO2 radicals. We ascribe this observation to the formation of vibrationally excited CF3CFHO* radicals in the CF3CFHO2 + NO reaction. Rapid decomposition of CF3-CFHO* radicals limits the formation of CF3C(O)F and hence CF3COOH in the atmospheric degradation of HFC-134a. We estimate that the CF3COOH yield from atmospheric oxidation of HFC-134a is 7-20%. Vibrationally excited alkoxy radicals may play an important role in the atmospheric chemistry of other organic compounds.",

author = "Wallington, {T. J.} and Hurley, {M. D.} and Fracheboud, {J. M.} and Orlando, {J. J.} and Tyndall, {G. S.} and J. Sehested and M{\o}gelberg, {T. E.} and Nielsen, {O. J.}",

year = "1996",

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language = "English",

volume = "100",

pages = "18116--18122",

journal = "Journal of Physical Chemistry",

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T1 - Role of excited CF3CFHO radicals in the atmospheric chemistry of HFC-134a

AU - Wallington, T. J.

AU - Hurley, M. D.

AU - Fracheboud, J. M.

AU - Orlando, J. J.

AU - Tyndall, G. S.

AU - Sehested, J.

AU - Møgelberg, T. E.

AU - Nielsen, O. J.

PY - 1996/11/14

Y1 - 1996/11/14

N2 - The atmospheric degradation of HFC-134a (CF3CFH2) proceeds via the formation of CF3CFHO radicals. Long path length FTIR environmental chamber techniques were used to study the atmospheric fate of CF3-CFHO radicals. Two competing reaction pathways were identified for CF3CFHO radicals: reaction with O2, CF3CFHO + O2 → CF3C(O)F + HO2, and decomposition via C-C bond scission, CF3CFHO + M → CF3 + HC(O)F + M. CF3CFHO radicals were produced by two different reactions: either via the self-reaction of CF3CFHO2 radicals or via the CF3CFHO2 + NO reaction. It was found that decomposition was much more important when CF3CFHO radicals were produced via the CF3CFHO2 + NO reaction than when they were produced via the self-reaction of CF3CFHO2 radicals. We ascribe this observation to the formation of vibrationally excited CF3CFHO* radicals in the CF3CFHO2 + NO reaction. Rapid decomposition of CF3-CFHO* radicals limits the formation of CF3C(O)F and hence CF3COOH in the atmospheric degradation of HFC-134a. We estimate that the CF3COOH yield from atmospheric oxidation of HFC-134a is 7-20%. Vibrationally excited alkoxy radicals may play an important role in the atmospheric chemistry of other organic compounds.

AB - The atmospheric degradation of HFC-134a (CF3CFH2) proceeds via the formation of CF3CFHO radicals. Long path length FTIR environmental chamber techniques were used to study the atmospheric fate of CF3-CFHO radicals. Two competing reaction pathways were identified for CF3CFHO radicals: reaction with O2, CF3CFHO + O2 → CF3C(O)F + HO2, and decomposition via C-C bond scission, CF3CFHO + M → CF3 + HC(O)F + M. CF3CFHO radicals were produced by two different reactions: either via the self-reaction of CF3CFHO2 radicals or via the CF3CFHO2 + NO reaction. It was found that decomposition was much more important when CF3CFHO radicals were produced via the CF3CFHO2 + NO reaction than when they were produced via the self-reaction of CF3CFHO2 radicals. We ascribe this observation to the formation of vibrationally excited CF3CFHO* radicals in the CF3CFHO2 + NO reaction. Rapid decomposition of CF3-CFHO* radicals limits the formation of CF3C(O)F and hence CF3COOH in the atmospheric degradation of HFC-134a. We estimate that the CF3COOH yield from atmospheric oxidation of HFC-134a is 7-20%. Vibrationally excited alkoxy radicals may play an important role in the atmospheric chemistry of other organic compounds.

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M3 - Journal article

AN - SCOPUS:33748481542

SN - 0022-3654

VL - 100

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EP - 18122

JO - Journal of Physical Chemistry

JF - Journal of Physical Chemistry

IS - 46

ER -

Role of excited CF₃CFHO radicals in the atmospheric chemistry of HFC-134a

Abstract

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