| Title: | Unexpected significance of a minor reaction pathway in daytime formation of biogenic highly oxygenated organic compounds |
| Author(s): | Shen H; Vereecken L; Kang S; Pullinen I; Fuchs H; Zhao D; Mentel TF; |
| Address: | "Department of Atmospheric and Oceanic Sciences & Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China. Institute of Energy and Climate Research, IEK-8: Troposphere, Forschungszentrum Julich GmbH, 52425 Julich, Germany. Physikalisches Institut, Universitat zu Koln, 50932 Koln, Germany. Shanghai Frontiers Science Center of Atmosphere-Ocean Interaction, Fudan University, Shanghai 200438, China. Institute of Eco-Chongming (IEC), 20 Cuiniao Rd., Chongming, Shanghai 202162, China. IRDR ICoE on Risk Interconnectivity and Governance on Weather/Climate Extremes Impact and Public Health, Fudan University, Shanghai 200438, China" |
| ISSN/ISBN: | 2375-2548 (Electronic) 2375-2548 (Linking) |
| Abstract: | "Secondary organic aerosol (SOA), formed by oxidation of volatile organic compounds, substantially influence air quality and climate. Highly oxygenated organic molecules (HOMs), particularly those formed from biogenic monoterpenes, contribute a large fraction of SOA. During daytime, hydroxyl radicals initiate monoterpene oxidation, mainly by hydroxyl addition to monoterpene double bonds. Naturally, related HOM formation mechanisms should be induced by that reaction route, too. However, for alpha-pinene, the most abundant atmospheric monoterpene, we find a previously unidentified competitive pathway under atmospherically relevant conditions: HOM formation is predominately induced via hydrogen abstraction by hydroxyl radicals, a generally minor reaction pathway. We show by observations and theoretical calculations that hydrogen abstraction followed by formation and rearrangement of alkoxy radicals is a prerequisite for fast daytime HOM formation. Our analysis provides an accurate mechanism and yield, demonstrating that minor reaction pathways can become major, here for SOA formation and growth and related impacts on air quality and climate" |
| Notes: | "PubMed-not-MEDLINEShen, Hongru Vereecken, Luc Kang, Sungah Pullinen, Iida Fuchs, Hendrik Zhao, Defeng Mentel, Thomas F eng 2022/10/22 Sci Adv. 2022 Oct 21; 8(42):eabp8702. doi: 10.1126/sciadv.abp8702. Epub 2022 Oct 21" |
