Atmospheric oxidation of indene initiated by OH radical in the presence of O2 and NO: A mechanistic and kinetic study.
Atmospheric oxidation of indene initiated by OH radical in the presence of O2 and NO: A mechanistic and kinetic study.
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DOI：
10.1016/j.chemosphere.2020.127331
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发表时间：
2020-06
期刊：
影响因子：
8.8
通讯作者：
Zhezheng Ding;Yayi Yi;Wen-xing Wang;Qingzhu Zhang
中科院分区：
文献类型：
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作者：
Zhezheng Ding;Yayi Yi;Wen-xing Wang;Qingzhu Zhang
多环芳烃（PAHs）在大气中的降解会产生有机污染物，这些有机污染物会促进二次有机气溶胶（SOAs）的形成，并加剧其致癌性。茚是不完全芳族的类苯乙烯双环烃的实例。采用量子化学方法在M06-2X/6-311++G（3df，2 p）//M06-2X/6-311+G（d，p）水平上研究了O2和NO存在下茚在OH引发下的常压氧化反应.氧化产物为含氧多环芳烃（OPAH），包括羟基茚、茚酮、二醛和2-（甲酰基甲基）苯甲醛。计算结果表明，7-茚自由基是多环芳烃的前体，在初始反应中产生率高达35.29%，表明OH引发的氧化增加了茚在大气中的环境风险。基于Rice-Ramsperger-Kassel-Marcus（RRKM）理论计算了关键基元反应的速率常数。初始反应的总速率常数为1.04 × 10− 10 cm 3 molecule − 1 s − 1，茚的大气寿命为2.74 h。这项工作提供了一个全面的了解茚的氧化机制和研究结果可能有助于澄清茚在大气中的命运。
The atmospheric degradation of polycyclic aromatic hydrocarbons (PAHs) can generate organic pollutants that contribute to the formation of secondary organic aerosols (SOAs) and exacerbate their carcinogenicity. Indene is an example of styrene-like bicyclic hydrocarbons that are not fully aromatic. The OH-initiated atmospheric oxidation of indene in the presence of O2and NO was investigated using quantum chemical methods at M06–2X/6–311++G(3df,2p)//M06–2X/6-311+G(d,p) level. The oxidation products are oxygenated polycyclic aromatic hydrocarbons (OPAHs) containing hydroxyindene, indenone, dialdehydes and 2-(formylmethyl)benzaldehyde. Calculation results showed that 7-indene radical, which is the precursor of various PAHs, has a high production ratio that is 35.29% in the initial reaction, indicating that the OH-initiated oxidation increase the environmental risks of indene in the atmosphere. The rate constants for the crucial elementary reactions were calculated based on Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The overall rate constant of the initial reaction is calculated to be 1.04 × 10−10cm3molecule−1s−1and the atmospheric lifetime of indene is determined as 2.74 h. This work provides a comprehensive understanding on the oxidation mechanisms of indene and the findings could help to clarify the fate of indene in the atmosphere.