Secondary Organic Aerosol Formation from Reaction of 3-Methylfuran with Nitrate Radicals
Secondary Organic Aerosol Formation from Reaction of 3-Methylfuran with Nitrate Radicals
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DOI：
10.1021/acsearthspacechem.9b00068
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发表时间：
2019-06-01
影响因子：
3.4
通讯作者：
Ng, Nga Lee
中科院分区：
文献类型：
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作者：
Joo, Taekyu;Rivera-Rios, Jean C.;Ng, Nga Lee
生物质燃烧排放出大量的呋喃类物质。它们对羟基（OH）和硝酸根（NO3）具有高度反应性，可导致二次有机气溶胶（SOA）的形成。在这里，我们研究气相氧化和SOA的形成3-甲基呋喃（C5 H6 O）通过NO3反应。实验在干燥条件（RH < 5%）下并且用不同的3-甲基呋喃初始浓度（从95.9至562.8ppb）进行。我们证明，这种反应导致SOA的形成，与SOA产率范围从1.6到2.4%的有机质量负荷范围从5.1到45 μ g/m（3）。超过一半的SOA质量是在3-甲基呋喃完全耗尽后产生的，这突出了更高代或多相反应对气溶胶形成的重要性。颗粒相有机硝酸盐占有机物的39.4%，其平均挥发性（平均C* = 10（-2.9）μ g/m3）高于非硝酸盐有机化合物的平均挥发性（平均C* = 10（-33）μ g/m3）。提出了一种反应机理的基础上确定的产品，和C5 H5 NO 5和C5 H6 O3被确定为在气相和颗粒相的主要物种，分别。低聚物的形成似乎决定了SOA的组成和形成速率，并且通过RO 2 + RO 2（酰基过氧自由基）反应和颗粒相吸积反应的气相ROOR'形成都可以导致观察到的二聚（C-10）化合物的形成。这项研究的结果提供了3-甲基呋喃氧化的详细化学，可以提高我们对夜间生物质燃烧羽流中SOA和臭氧形成的影响的理解。
A significant amount of furan species is emitted from biomass burning. They are highly reactive to hydroxyl (OH) and nitrate radicals (NO3), which can lead to the formation of secondary organic aerosol (SOA). Here, we investigate gas-phase oxidation and SOA formation from 3-methylfuran (C5H6O) via NO3 reaction. Experiments are performed under dry conditions (RH < 5%) and with different initial concentrations of 3-methylfuran (from 95.9 to 562.8 ppb). We demonstrate that this reaction leads to SOA formation, with SOA yield ranging from 1.6 to 2.4% for organic mass loading ranging from 5.1 to 45 mu g/m(3). More than half of the SOA mass is generated after complete depletion of 3-methylfuran, highlighting the importance of higher-generation or multiphase reactions to aerosol formation. Particle-phase organic nitrates contribute 39.4% of organics and their average volatility (average C* = 10(-2.9) mu g/m(3)) is higher than that of non-nitrate organic compounds (average C* = 10(-33) mu g/m(3)). A reaction mechanism is proposed based on the identified products, and C5H5NO5 and C5H6O3 are determined to be the major species in the gas and particle phases, respectively. Oligomer formation appears to determine the SOA composition and formation rate, and both gas-phase ROOR' formation via RO2 + RO2 (acylperoxy radical) reactions and particle-phase accretion reactions can lead to the formation of the dimeric (C-10) compounds observed. Results from this study provide detailed chemistry of 3-methylfuran oxidation that can improve our understanding of its impact on SOA and ozone formation in nighttime biomass burning plumes.