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Titel |
Substrate effects in the photoenhanced ozonation of pyrene |
VerfasserIn |
S. A. Styler, M.-E. Loiseaux, D. J. Donaldson |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 11, no. 3 ; Nr. 11, no. 3 (2011-02-14), S.1243-1253 |
Datensatznummer |
250009305
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Publikation (Nr.) |
copernicus.org/acp-11-1243-2011.pdf |
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Zusammenfassung |
We report the effects of actinic illumination on the
heterogeneous ozonation kinetics of solid pyrene films and pyrene adsorbed
at air-octanol and air-aqueous interfaces. Upon illumination, the
ozonation of solid pyrene films and pyrene at the air-aqueous interface
proceeds more quickly than in darkness; no such enhancement is observed for
pyrene at the air-octanol interface. Under dark conditions, the reaction of
pyrene at all three interfaces proceeds via a Langmuir-Hinshelwood-type
surface mechanism. In the presence of light, Langmuir-Hinshelwood kinetics
are observed for solid pyrene films but a linear dependence upon gas-phase
ozone concentration is observed at the air-aqueous interface. We interpret
these results as evidence of the importance of charge-transfer pathways for
the ozonation of excited-state pyrene. The dramatically different behaviour
of pyrene at the surface of these three simple reaction environments
highlights the difficulties inherent in representing complex reactive
surfaces in the laboratory, and suggests caution in extrapolating laboratory
results to environmental surfaces. |
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