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DOI	10.5194/acp-21-7845-2021
	On the similarities and differences between the products of oxidation of hydrocarbons under simulated atmospheric conditions and cool flames
	Benoit R.; Belhadj N.; Lailliau M.; Dagaut P.
发表日期	2021
ISSN	1680-7316
起始页码	7845
结束页码	7862
卷号	21 期号:10
英文摘要	Atmospheric oxidation chemistry and, more specifically, photooxidation show that the long-term oxidation of organic aerosol (OA) progressively erases the initial signature of the chemical compounds and can lead to a relatively uniform character of oxygenated organic aerosol (OOA). This uniformity character observed after a long reaction time seems to contrast with the great diversity of reaction mechanisms observed in the early stages of oxidation. The numerous studies carried out on the oxidation of terpenes, and more particularly on limonene for its diversity of reaction sites (endo- A nd oxocyclic), allow this evolution to be studied. We have selected, for their diversity of experimental conditions, nine studies of limonene oxidation at room temperature over long reaction times to be compared to the present data set obtained at elevated temperature and short reaction time in order to investigate the similarities in terms of reaction mechanisms and chemical species formed. Here, the oxidation of limonene-oxygen-nitrogen mixtures was studied using a jet-stirred reactor at elevated temperature and atmospheric pressure. Samples of the reacting mixtures were collected and analyzed by highresolution mass spectrometry (Orbitrap) after direct injection or after separation by reverse-phase ultra-high-pressure liquid chromatography and soft ionization, i.e., (+/-) HESI and (+/-) APCI. Unexpectedly, because of the diversity of experimental conditions in terms of continuous-flow tank reactor, concentration of reactants, temperature, reaction time, mass spectrometry techniques, and analysis conditions, the results indicate that among the 1138 presently detected molecular formulae, many oxygenates found in earlier studies of limonene oxidation by OH and/or ozone are also produced under the present conditions. Among these molecular formulae, highly oxygenated molecules and oligomers were detected in the present work. The results are discussed in terms of reaction pathways involving the initial formation of peroxy radicals (RO2), isomerization reactions yielding keto-hydroperoxides, and other oxygenated intermediates and products up to C25H32O17, products which could derive from RO2 autoxidation via sequential H shift and O2 addition (C10H14O3,5,7,9,11) and products deriving from the oxidation of alkoxy radicals (produced by RO2 self-reaction or reaction with HO2) through multiple H shifts and O2 additions (C10H14O2,4,6,8,10). The oxidation of RO2, with possible occurrence of the Waddington mechanism and of the Korcek mechanism, involving H shifts is also discussed. The present work demonstrates similitude between the oxidation products and oxidation pathways of limonene under simulated atmospheric conditions and in those encountered during the self-ignition of hydrocarbons at elevated temperatures. These results complement those recently reported by Vereecken and Noziere and confirm for limonene the existence of an oxidative chemistry of the alkylperoxy radical beyond 450K based on the H shift (Noziere and Vereecken, 2019; Vereecken and Noziere, 2020). © 2021 Author(s).
语种	英语
scopus关键词	atmospheric chemistry; hydrocarbon; nitrogen; oxidation; oxygen; terpene
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246870
作者单位	CNRS-INSIS, ICARE, Orleáns, France; Université d'Orleáns, Orleáns, France
推荐引用方式 GB/T 7714	Benoit R.,Belhadj N.,Lailliau M.,et al. On the similarities and differences between the products of oxidation of hydrocarbons under simulated atmospheric conditions and cool flames[J],2021,21(10).
APA	Benoit R.,Belhadj N.,Lailliau M.,&Dagaut P..(2021).On the similarities and differences between the products of oxidation of hydrocarbons under simulated atmospheric conditions and cool flames.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(10).
MLA	Benoit R.,et al."On the similarities and differences between the products of oxidation of hydrocarbons under simulated atmospheric conditions and cool flames".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.10(2021).