Impact of Criegee Intermediate Reactions with Peroxy Radicals on Tropospheric Organic Aerosol
Impact of Criegee Intermediate Reactions with Peroxy Radicals on Tropospheric Organic Aerosol
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DOI：
10.1021/acsearthspacechem.0c00147
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发表时间：
2020-10-15
影响因子：
3.4
通讯作者：
Orr-Ewing, Andrew J.
中科院分区：
文献类型：
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作者：
Chhantyal-Pun, Rabi;Khan, M. Anwar H.;Orr-Ewing, Andrew J.
过氧自由基和羰基氧化物（Criegee 中间体）是在 OH 和臭氧引发的碳氢化合物氧化过程中在对流层中产生的。先前已证明这些物质之间的反应会形成高度氧化的分子，这些分子可以凝结形成二次有机气溶胶。这里，腔衰荡光谱与激光闪光光解相结合用于直接测量 CH2OO 与 CH3O2 和 CH3C(O)O-2 反应的速率系数。发现速率系数在测量不确定度内相似，并且仅较弱地依赖于温度（243-310 K 范围内）和压力（20-100 Torr，N-2）。在这些条件下获得的组合速率系数为k(CH2OO+RO2，RO2=CH3O2/CH3C(O)O-2)=(2.4+/-1.2)×10(-11)cm(3)分子(-1)s(-1)。使用 STOCHEM-CRI 进行的全球建模，通过生成 Criegee 中间体的单萜化学进行更新，并辅以区域盒模型，表明此类 Criegee 中间体 + 过氧自由基反应可贡献约 1.3% 的世界森林地区二次有机气溶胶产量。
Peroxy radicals and carbonyl oxides (Criegee intermediates) are produced in the troposphere during OH and ozone-initiated oxidation of hydrocarbons. Reactions between these species have previously been shown to form highly oxidized molecules which can condense to form secondary organic aerosols. Here, cavity ring-down spectroscopy coupled with laser flash photolysis was used to measure directly rate coefficients for reactions of CH2OO with CH3O2 and CH3C(O)O-2. The rate coefficients were found to be similar within the measurement uncertainties and only weakly dependent on temperature (in the range 243-310 K) and pressure (20-100 Torr, N-2). A combined rate coefficient of k (CH2OO + RO2, RO2 = CH3O2/CH3C(O)O-2) = (2.4 +/- 1.2) x 10(-11) cm(3) molecule(-1) s(-1) was obtained under these conditions. Global modeling using STOCHEM-CRI, updated with monoterpene chemistry generating Criegee intermediates and supplemented by regional box modeling, shows that this class of Criegee intermediate + peroxy radical reactions can contribute up to similar to 1.3% of secondary organic aerosol production in forested regions of the world.