大气化学与全球气候变化 - Atmospheric Chemistry and Global Climate Change Research Group @ IAP CAS - Page 2

New Publication: ozone formation potential of acetaldehyde

组内消息 2021-06-11

乙醛是大气环境中重要的含氧的挥发性有机物(OVOC),是臭氧生成的重要前体物。目前已有研究表明,在部分城市地区乙醛对臭氧污染的贡献已经高于其他OVOC。然而,目前关于乙醛光化学反应的烟雾箱实验研究较少,仅有的实验研究主要关注在低相对湿度(RH)条件下不同光照强度对乙醛光化学反应臭氧生成的影响,而关于RH和反应前体物浓度比值的影响规律目前仍未见报道。此外,目前广泛应用的近显式化学反应机制MCM(Master Chemical Mechanism)对乙醛光化学反应的模拟准确性仍然有待评估,并且由于乙醛同样是其他VOC物种光化学反应的中间产物,因此MCM机理对乙醛光化学反应模拟的准确性显得尤为重要。本研究结合烟雾箱实验和数值模拟方法对乙醛光化学反应过程进行了详细研究。
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气溶胶水中锰铁离子催化氧化二氧化硫的反应动力学

组内消息 2020-10-30

近年来SO2在气溶胶表面的非均相反应被认为是大气污染期间硫酸盐的一种重要来源。本文在烟雾箱中研究了气溶胶水中锰离子和铁离子催化氧化SO2的反应动力学。得到了气溶胶水中锰离子催化氧化SO2反应的动力学,发现与本体水不同,锰离子在离子强度很高的气溶胶水中催化氧化SO2的反应速率比同等条件下本体水中速率提高了2个数量级,而铁离子离子在颗粒水中并没有表现出催化氧化SO2的性质。确定气溶胶水中锰离子和铁离子协同催化氧化SO2作用有限。一般约20%的SO2可通过非均相反应氧化,本研究进一步确定了非均相反应中的48% - 86%的硫酸盐来自气溶胶水中锰离子和铁离子催化氧化。该研究成果已经发表在Atmospheric Environment上。

Highlight
• Catalytic oxidation of SO2 with low concentrations by metal ions has been studied in aerosol water.
• The Mn2+-catalytic oxidation rate of SO2 by O2 in aerosol water is 2 orders of magnitude higher than that in bulk water.
• Fe3+ and Mn2+ may only have a small synergistic catalysis in aerosol water, which is not as significant as in bulk water.

Zhang, H., Xu, Y., Jia, L., 2021. A chamber study of catalytic oxidation of SO2 by Mn2+/Fe3+ in aerosol water. Atmos. Environ. 245, 118019. https://doi.org/10.1016/j.atmosenv.2020.118019

New publication in STE:The functional group signatures of aerosol from α-pinene

组内消息 2020-06-01

The role of functional groups in the understanding of secondary organic aerosol formation mechanism from α-pinene

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Highlights
•The SOA is characterized by O–H groups in the OH channel and C=O groups in the O3 channel

•The nO−H/nC=O ratio is a good parameter in revealing the difference of SOA between the O3 and OH oxidation channels

•The SOA from OH channel is mainly formed by autoxidation of RO2 radicals

•Different structures of RO2 radicals are responsible for the difference functional group signatures of SOA

Full text:https://doi.org/10.1016/j.scitotenv.2020.139831