Aqueous production of secondary organic aerosol from fossil fuel emissions in winter Beijing haze
Aqueous production of secondary organic aerosol from fossil fuel emissions in winter Beijing haze
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北京冬季雾霾中化石燃料排放产生的二次有机气溶胶的水相
DOI：
10.1073/pnas.2022179118
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发表时间：
2021
影响因子：
11.1
通讯作者：
C
中科院分区：
文献类型：
--
作者：
Wang Junfeng;Ye Jianhuai;Zhang Qi;Zhao Jian;Wu Yangzhou;Li Jingyi;Liu Dantong;Li Weijun;Zhang Yange;Wu Cheng;Xie Conghui;Qin Yiming;Lei Yali;Huang Xiangpeng;Guo Jianping;Liu Pengfei;Fu Pingqing;Li Yongjie;Lee Hyun Chul;Choi Hyoungwoo;Zhang Jie;Liao Hong;C
二次有机气溶胶（SOA）是由大气中一次排放的前体物质氧化产生的，是全球细颗粒物（PM2.5）空气污染的主要贡献者。在中国城市冬季雾霾污染事件的观察表明，这种SOA的大部分来源于化石燃料燃烧，但所涉及的化学机制尚不清楚。在这里，我们报告了在北京冬季雾霾事件的现场观测，揭示了快速的水相转换的化石燃料的初级有机气溶胶（POA）SOA在高相对湿度。气溶胶质谱和元素比的分析表明，开环氧化的POA芳香族物种，导致官能化的羰基和羧酸，可能是这种SOA形成的主导机制。SOA的POA起源可以解释为什么SOA在2013-2018年期间一直在减少，以应对POA排放控制，即使挥发性有机化合物（VOCs）的排放量保持不变。
Secondary organic aerosol (SOA) produced by atmospheric oxidation of primary emitted precursors is a major contributor to fine particulate matter (PM2.5) air pollution worldwide. Observations during winter haze pollution episodes in urban China show that most of this SOA originates from fossil-fuel combustion but the chemical mechanisms involved are unclear. Here we report field observations in a Beijing winter haze event that reveal fast aqueous-phase conversion of fossil-fuel primary organic aerosol (POA) to SOA at high relative humidity. Analyses of aerosol mass spectra and elemental ratios indicate that ring-breaking oxidation of POA aromatic species, leading to functionalization as carbonyls and carboxylic acids, may serve as the dominant mechanism for this SOA formation. A POA origin for SOA could explain why SOA has been decreasing over the 2013–2018 period in response to POA emission controls even as emissions of volatile organic compounds (VOCs) have remained flat.