Nitrate radical generation via continuous generation of dinitrogen pentoxide in a laminar flow reactor coupled to an oxidation flow reactor
Nitrate radical generation via continuous generation of dinitrogen pentoxide in a laminar flow reactor coupled to an oxidation flow reactor
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DOI：
10.5194/amt-2019-470-supplement
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发表时间：
2020-01
影响因子：
3.8
通讯作者：
A. Lambe;E. Wood;J. Krechmer;Francesca Majluf;L. Williams;P. Croteau;M. Cirtog;A. Féron;Jean-Eudes Petit;A. Albinet;J. Jimenez;Zhe Peng
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文献类型：
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作者：
A. Lambe;E. Wood;J. Krechmer;Francesca Majluf;L. Williams;P. Croteau;M. Cirtog;A. Féron;Jean-Eudes Petit;A. Albinet;J. Jimenez;Zhe Peng
抽象的。氧化流动反应器（OFR）是研究有机气溶胶的形成和氧化老化以及其他应用的新兴工具。迄今为止，大多数OFR研究都涉及羟基自由基（OH）的产生，以模拟白天的氧化老化过程。相比之下，由于用于产生NO3的常规技术的复杂性，在现代OFR中使用硝酸根（NO3）来模拟夜间氧化老化过程受到限制。在这里，我们提出了一种新的方法，使用层流反应器（LFR），连续产生五氧化二氮（N2 O 5）在气相中在室温下从NO2 + O3和NO2 + NO3反应。然后将N2 O 5注入暗势气溶胶团（PAM）OFR中并分解生成NO3;此后，该方法被称为“OFR-1 N2 O 5”（其中“i”代表“注入”）。为了评估OFR-iN 2 O 5方法对不同化学系统的适用性，我们提出了实验和模型表征的综合NO3暴露，NO3：O3，NO2：NO3，NO2：O2作为LFR和OFR条件的函数。这些参数被用来调查的命运的代表性的有机过氧自由基（RO 2）和芳香族烷基自由基产生的挥发性有机化合物（VOC）+ NO3反应，和挥发性有机化合物是对O3和NO3的反应。最后，我们证明了OFR-iN 2 O 5的方法产生和表征二次有机气溶胶从β-蒎烯+ NO3反应。
Abstract. Oxidation flow reactors (OFRs) are an emerging tool for studying the formation and oxidative aging of organic aerosols and other applications. The majority of OFR studies to date have involved the generation of the hydroxyl radical (OH) to mimic daytime oxidative aging processes. In contrast, the use of the nitrate radical (NO3) in modern OFRs to mimic nighttime oxidative aging processes has been limited due to the complexity of conventional techniques that are used to generate NO3. Here, we present a new method that uses a laminar flow reactor (LFR) to continuously generate dinitrogen pentoxide (N2O5) in the gas phase at room temperature from the NO2 + O3 and NO2 + NO3 reactions. The N2O5 is then injected into a dark Potential Aerosol Mass (PAM) OFR and decomposes to generate NO3; hereafter, this method is referred to as “OFR-iN2O5” (where “i” stands for “injected”). To assess the applicability of the OFR-iN2O5 method towards different chemical systems, we present experimental and model characterization of the integrated NO3 exposure, NO3:O3, NO2:NO3, and NO2:O2 as a function of LFR and OFR conditions. These parameters were used to investigate the fate of representative organic peroxy radicals (RO2) and aromatic alkyl radicals generated from volatile organic compound (VOC) + NO3 reactions, and VOCs that are reactive towards both O3 and NO3. Finally, we demonstrate the OFR-iN2O5 method by generating and characterizing secondary organic aerosol from the β-pinene + NO3 reaction.