Pichelstorfer Lukas, Roldin Pontus, Rissanen Matti, Hyttinen Noora, Garmash Olga, Xavier Carlton, Zhou Putian, Clusius Petri, Foreback Benjamin, Golin Almeida Thomas, Deng Chenjuan, Baykara Metin, Kurten Theo, Boy Michael
pi-numerics Neumarkt amW. 5202 Austria
Chemistry and Physics of Materials, University of Salzburg A-5020 Austria.
Environ Sci Atmos. 2024 Jul 9;4(8):879-896. doi: 10.1039/d4ea00054d. eCollection 2024 Aug 8.
In the last few decades, atmospheric formation of secondary organic aerosols (SOA) has gained increasing attention due to their impact on air quality and climate. However, methods to predict their abundance are mainly empirical and may fail under real atmospheric conditions. In this work, a close-to-mechanistic approach allowing SOA quantification is presented, with a focus on a chain-like chemical reaction called "autoxidation". A novel framework is employed to (a) describe the gas-phase chemistry, (b) predict the products' molecular structures and (c) explore the contribution of autoxidation chemistry on SOA formation under various conditions. As a proof of concept, the method is applied to benzene, an important anthropogenic SOA precursor. Our results suggest autoxidation to explain up to 100% of the benzene-SOA formed under low-NO laboratory conditions. Under atmospheric-like day-time conditions, the calculated benzene-aerosol mass continuously forms, as expected based on prior work. Additionally, a prompt increase, driven by the NO radical, is predicted by the model at dawn. This increase has not yet been explored experimentally and stresses the potential for atmospheric SOA formation secondary oxidation of benzene by O and NO.
在过去几十年中，二次有机气溶胶（SOA）的大气形成因其对空气质量和气候的影响而受到越来越多的关注。然而，预测其丰度的方法主要是经验性的，在实际大气条件下可能会失效。在这项工作中，提出了一种接近机理的方法来定量SOA，重点关注一种称为“自氧化”的链状化学反应。采用了一个新颖的框架来（a）描述气相化学，（b）预测产物的分子结构，以及（c）探索自氧化化学在各种条件下对SOA形成的贡献。作为概念验证，该方法应用于苯，一种重要的人为SOA前体。我们的结果表明，在低NO实验室条件下，自氧化可解释高达100%的苯-SOA形成。在类似大气的白天条件下，计算出的苯气溶胶质量持续形成，这与先前工作的预期一致。此外，模型预测在黎明时由NO自由基驱动会迅速增加。这种增加尚未通过实验进行探索，并强调了通过O和NO对苯进行二次氧化形成大气SOA的潜力。
