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Multi-generation oxidation mechanism of M-xylene: Unexpected implications for secondary organic aerosol formation
https://orcid.org/0009-0004-8578-1009
https://orcid.org/0000-0003-0803-7337
Abstract Secondary organic aerosol (SOA) affects air quality, human health and climate. The multi-generation reactions of volatile organic compounds (VOCs) have become key process for explaining the SOA formation. M-xylene, as one of the most important VOCs in urban atmosphere, has got extensive study. However, the reaction mechanism of the first-generation products hydroperoxides (M-ROOH) and organonitrates (M-RONO2) remain unknown. In this work, the hydroxyl radicals (·OH) initiated reactions of M-ROOH and M-RONO2 were investigated by employing quantum chemical methods and kinetics modeling. The results show that new ring-retaining epoxides, a range of dialdehydes and less volatile hydroperoxides and organonitrates are formed, contributing to SOA formation. By adopting the unveiled new mechanism into the SOSAA box modeling, we found that the yield of SOA from m-xylene oxidation is up to 38%, which is comparable to the experimental value (36%). This work advances current understanding of multi-generation chemistry and elucidates the role of aromatic hydrocarbons oxidation in the formation of SOA.
Graphical abstract Display Omitted
Highlights The formation mechanism of a novel epoxides formed from second-generation oxidation of m-xylene was revealed. The contribution (∼33%) of m-xylene oxidation to the SOA formation was evaluated by box model. Epoxides formed by hydroperoxides and organonitrates derived from AHs are highly structurally dependent.
Multi-generation oxidation mechanism of M-xylene: Unexpected implications for secondary organic aerosol formation
https://orcid.org/0009-0004-8578-1009
https://orcid.org/0000-0003-0803-7337
Abstract Secondary organic aerosol (SOA) affects air quality, human health and climate. The multi-generation reactions of volatile organic compounds (VOCs) have become key process for explaining the SOA formation. M-xylene, as one of the most important VOCs in urban atmosphere, has got extensive study. However, the reaction mechanism of the first-generation products hydroperoxides (M-ROOH) and organonitrates (M-RONO2) remain unknown. In this work, the hydroxyl radicals (·OH) initiated reactions of M-ROOH and M-RONO2 were investigated by employing quantum chemical methods and kinetics modeling. The results show that new ring-retaining epoxides, a range of dialdehydes and less volatile hydroperoxides and organonitrates are formed, contributing to SOA formation. By adopting the unveiled new mechanism into the SOSAA box modeling, we found that the yield of SOA from m-xylene oxidation is up to 38%, which is comparable to the experimental value (36%). This work advances current understanding of multi-generation chemistry and elucidates the role of aromatic hydrocarbons oxidation in the formation of SOA.
Graphical abstract Display Omitted
Highlights The formation mechanism of a novel epoxides formed from second-generation oxidation of m-xylene was revealed. The contribution (∼33%) of m-xylene oxidation to the SOA formation was evaluated by box model. Epoxides formed by hydroperoxides and organonitrates derived from AHs are highly structurally dependent.
Multi-generation oxidation mechanism of M-xylene: Unexpected implications for secondary organic aerosol formation
https://orcid.org/0009-0004-8578-1009
https://orcid.org/0000-0003-0803-7337
Abstract Secondary organic aerosol (SOA) affects air quality, human health and climate. The multi-generation reactions of volatile organic compounds (VOCs) have become key process for explaining the SOA formation. M-xylene, as one of the most important VOCs in urban atmosphere, has got extensive study. However, the reaction mechanism of the first-generation products hydroperoxides (M-ROOH) and organonitrates (M-RONO2) remain unknown. In this work, the hydroxyl radicals (·OH) initiated reactions of M-ROOH and M-RONO2 were investigated by employing quantum chemical methods and kinetics modeling. The results show that new ring-retaining epoxides, a range of dialdehydes and less volatile hydroperoxides and organonitrates are formed, contributing to SOA formation. By adopting the unveiled new mechanism into the SOSAA box modeling, we found that the yield of SOA from m-xylene oxidation is up to 38%, which is comparable to the experimental value (36%). This work advances current understanding of multi-generation chemistry and elucidates the role of aromatic hydrocarbons oxidation in the formation of SOA.
Graphical abstract Display Omitted
Highlights The formation mechanism of a novel epoxides formed from second-generation oxidation of m-xylene was revealed. The contribution (∼33%) of m-xylene oxidation to the SOA formation was evaluated by box model. Epoxides formed by hydroperoxides and organonitrates derived from AHs are highly structurally dependent.
Multi-generation oxidation mechanism of M-xylene: Unexpected implications for secondary organic aerosol formation
Lu, Ruiqi (author) / Zhou, Putian (author) / Ma, Fangfang (author) / Zhao, Qiaojing (author) / Peng, Xiaoke (author) / Chen, Jingwen (author) / Xie, Hong-Bin (author)
Atmospheric Environment ; 327
2024-04-03
Article (Journal)
Electronic Resource
English
Secondary organic aerosol formation from the photo-oxidation of benzene
| Elsevier | 2011