气候变化领域集成服务门户(CCPortal): Heterogeneous oxidation of amorphous organic aerosol surrogates by O3, NO3, and OH at typical tropospheric temperatures

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DOI	10.5194/acp-20-6055-2020
	Heterogeneous oxidation of amorphous organic aerosol surrogates by O3, NO3, and OH at typical tropospheric temperatures
	Li J.; Forrester S.M.; Knopf D.A.
发表日期	2020
ISSN	16807316
起始页码	6055
结束页码	6080
卷号	20 期号:10
英文摘要	Typical tropospheric temperatures render possible phase states of amorphous organic aerosol (OA) particles of solid, semisolid, and liquid. This will affect the multiphase oxidation kinetics involving the organic condensedphase and gaseous oxidants and radicals. To quantify this effect, we determined the reactive uptake coefficients (γ) of O3, NO3, and OH by substrate films composed of single and binary OA surrogate species under dry conditions for temperatures from 213 to 313 K. A temperature-controlled coated-wall flow reactor coupled to a chemical ionization mass spectrometer was applied to determine γ with consideration of gas diffusion transport limitation and gas flow entrance effects, which can impact heterogeneous reaction kinetics. The phase state of the organic substrates was probed via the poke-flow technique, allowing the estimation of the substrates' glass transition temperatures. γ values for O3 and OH uptake to a canola oil substrate, NO3 uptake to a levoglucosan and a levoglucosan/xylitol substrate, and OH uptake to a glucose and glucose/1,2,6-hexanetriol substrate have been determined as a function of temperature. We observed the greatest changes in γ with temperature for substrates that experienced the largest changes in viscosity as a result of a solid-to-liquid phase transition. Organic substrates that maintain a semisolid or solid phase state and as such a relatively higher viscosity do not display large variations in heterogeneous reactivity. From 213 to 293 K, γ values of O3 with canola oil, of NO3 with a levoglucosan/xylitol mixture, and of OH with a glucose/1,2,6-hexanetriol mixture and canola oil, increase by about a factor of 34, 3, 2, and 5, respectively, due to a solid-to-liquid phase transition of the substrate. These results demonstrate that the surface and bulk lifetime of the OA surrogate species can significantly increase due to the slowed heterogeneous kinetics when OA species are solid or highly viscous in the middle and upper troposphere. This experimental study will further our understanding of the chemical evolution of OA particles with subsequent important consequences for source apportionment, air quality, and climate. © Author(s) 2020.
关键词	aerosol air temperature amorphous medium gas flow hydroxide nitrate oxidation ozone surrogate method troposphere Brassica napus var. napus
语种	英语
来源机构	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/132016
推荐引用方式 GB/T 7714	Li J.,Forrester S.M.,Knopf D.A.. Heterogeneous oxidation of amorphous organic aerosol surrogates by O3, NO3, and OH at typical tropospheric temperatures[J]. Atmospheric Chemistry and Physics,2020,20(10).
APA	Li J.,Forrester S.M.,&Knopf D.A..(2020).Heterogeneous oxidation of amorphous organic aerosol surrogates by O3, NO3, and OH at typical tropospheric temperatures.,20(10).
MLA	Li J.,et al."Heterogeneous oxidation of amorphous organic aerosol surrogates by O3, NO3, and OH at typical tropospheric temperatures".20.10(2020).