Impact of molecular structure on secondary organic aerosol formation from aromatic hydrocarbon photooxidation under low-NO<sub><i>x</i></sub> conditions
The molecular structure of volatile organic compounds determines their oxidation pathway, directly impacting secondary organic aerosol (SOA) formation. This study comprehensively investigates the impact of molecular structure on SOA formation from the photooxidation of 12 different eight- to nin...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2016-08-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/10793/2016/acp-16-10793-2016.pdf |
| _version_ | 1818179842790653952 |
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| author | L. Li L. Li P. Tang P. Tang S. Nakao S. Nakao S. Nakao D. R. Cocker III D. R. Cocker III |
| author_facet | L. Li L. Li P. Tang P. Tang S. Nakao S. Nakao S. Nakao D. R. Cocker III D. R. Cocker III |
| author_sort | L. Li |
| collection | DOAJ |
| description | The molecular structure of volatile organic compounds determines their
oxidation pathway, directly impacting secondary organic aerosol (SOA)
formation. This study comprehensively investigates the impact of molecular
structure on SOA formation from the photooxidation of 12 different eight-
to nine-carbon aromatic hydrocarbons under low-NO<sub><i>x</i></sub> conditions. The
effects of the alkyl substitute number, location, carbon chain length and
branching structure on the photooxidation of aromatic hydrocarbons are
demonstrated by analyzing SOA yield, chemical composition and physical
properties. Aromatic hydrocarbons, categorized into five groups, show a yield
order of ortho (<i>o</i>-xylene and <i>o</i>-ethyltoluene) > one substitute
(ethylbenzene, propylbenzene and isopropylbenzene) > meta
(<i>m</i>-xylene and <i>m</i>-ethyltoluene) > three substitute
(trimethylbenzenes) > para (<i>p</i>-xylene and <i>p</i>-ethyltoluene). SOA
yields of aromatic hydrocarbon photooxidation do not monotonically decrease
when increasing alkyl substitute number. The ortho position promotes SOA
formation while the para position suppresses aromatic oxidation and SOA
formation. Observed SOA chemical composition and volatility confirm that
higher yield is associated with further oxidation. SOA chemical composition
also suggests that aromatic oxidation increases with increasing alkyl
substitute chain length and branching structure. Further, carbon dilution
conjecture developed by Li et al. (2016) is extended in this study to serve
as a standard method to determine the extent of oxidation of an alkyl-substituted aromatic hydrocarbon. |
| first_indexed | 2024-12-11T21:10:18Z |
| format | Article |
| id | doaj.art-d4355c9553554798bc1b7e7381d25e1b |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-11T21:10:18Z |
| publishDate | 2016-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-d4355c9553554798bc1b7e7381d25e1b2022-12-22T00:50:45ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242016-08-0116107931080810.5194/acp-16-10793-2016Impact of molecular structure on secondary organic aerosol formation from aromatic hydrocarbon photooxidation under low-NO<sub><i>x</i></sub> conditionsL. Li0L. Li1P. Tang2P. Tang3S. Nakao4S. Nakao5S. Nakao6D. R. Cocker III7D. R. Cocker III8University of California, Riverside, Department of Chemical and Environmental Engineering, Riverside, CA 92507, USACollege of Engineering – Center for Environmental Research and Technology (CE-CERT), Riverside, CA 92507, USAUniversity of California, Riverside, Department of Chemical and Environmental Engineering, Riverside, CA 92507, USACollege of Engineering – Center for Environmental Research and Technology (CE-CERT), Riverside, CA 92507, USAUniversity of California, Riverside, Department of Chemical and Environmental Engineering, Riverside, CA 92507, USACollege of Engineering – Center for Environmental Research and Technology (CE-CERT), Riverside, CA 92507, USAcurrently at: Clarkson University, Department of Chemical and Biomolecular Engineering, Potsdam, NY 13699, USAUniversity of California, Riverside, Department of Chemical and Environmental Engineering, Riverside, CA 92507, USACollege of Engineering – Center for Environmental Research and Technology (CE-CERT), Riverside, CA 92507, USAThe molecular structure of volatile organic compounds determines their oxidation pathway, directly impacting secondary organic aerosol (SOA) formation. This study comprehensively investigates the impact of molecular structure on SOA formation from the photooxidation of 12 different eight- to nine-carbon aromatic hydrocarbons under low-NO<sub><i>x</i></sub> conditions. The effects of the alkyl substitute number, location, carbon chain length and branching structure on the photooxidation of aromatic hydrocarbons are demonstrated by analyzing SOA yield, chemical composition and physical properties. Aromatic hydrocarbons, categorized into five groups, show a yield order of ortho (<i>o</i>-xylene and <i>o</i>-ethyltoluene) > one substitute (ethylbenzene, propylbenzene and isopropylbenzene) > meta (<i>m</i>-xylene and <i>m</i>-ethyltoluene) > three substitute (trimethylbenzenes) > para (<i>p</i>-xylene and <i>p</i>-ethyltoluene). SOA yields of aromatic hydrocarbon photooxidation do not monotonically decrease when increasing alkyl substitute number. The ortho position promotes SOA formation while the para position suppresses aromatic oxidation and SOA formation. Observed SOA chemical composition and volatility confirm that higher yield is associated with further oxidation. SOA chemical composition also suggests that aromatic oxidation increases with increasing alkyl substitute chain length and branching structure. Further, carbon dilution conjecture developed by Li et al. (2016) is extended in this study to serve as a standard method to determine the extent of oxidation of an alkyl-substituted aromatic hydrocarbon.https://www.atmos-chem-phys.net/16/10793/2016/acp-16-10793-2016.pdf |
| spellingShingle | L. Li L. Li P. Tang P. Tang S. Nakao S. Nakao S. Nakao D. R. Cocker III D. R. Cocker III Impact of molecular structure on secondary organic aerosol formation from aromatic hydrocarbon photooxidation under low-NO<sub><i>x</i></sub> conditions Atmospheric Chemistry and Physics |
| title | Impact of molecular structure on secondary organic aerosol formation from
aromatic hydrocarbon photooxidation under low-NO<sub><i>x</i></sub> conditions |
| title_full | Impact of molecular structure on secondary organic aerosol formation from
aromatic hydrocarbon photooxidation under low-NO<sub><i>x</i></sub> conditions |
| title_fullStr | Impact of molecular structure on secondary organic aerosol formation from
aromatic hydrocarbon photooxidation under low-NO<sub><i>x</i></sub> conditions |
| title_full_unstemmed | Impact of molecular structure on secondary organic aerosol formation from
aromatic hydrocarbon photooxidation under low-NO<sub><i>x</i></sub> conditions |
| title_short | Impact of molecular structure on secondary organic aerosol formation from
aromatic hydrocarbon photooxidation under low-NO<sub><i>x</i></sub> conditions |
| title_sort | impact of molecular structure on secondary organic aerosol formation from aromatic hydrocarbon photooxidation under low no sub i x i sub conditions |
| url | https://www.atmos-chem-phys.net/16/10793/2016/acp-16-10793-2016.pdf |
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