Power Jennifer, Somers Kieran P, Nagaraja Shashank S, Wyrebak Weronika, Curran Henry J
Combustion Chemistry Centre, School of Chemistry & Ryan Institute, National University of Ireland Galway H91TK33, Ireland.
J Phys Chem A. 2020 Dec 24;124(51):10649-10666. doi: 10.1021/acs.jpca.0c06389. Epub 2020 Dec 15.
This paper presents a comprehensive potential energy surface (PES) for hydrogen atom addition to and abstraction from 2-methyl-1-butene, 2-methyl-2-butene, and 3-methyl-1-butene and the subsequent ß-scission and H atom transfer reactions. Thermochemical parameters for species on the ĊH potential energy surface (PES) were calculated as a function of temperature (298-2000 K), using a series of isodesmic reactions to determine the formation enthalpies. High-pressure limiting and pressure-dependent rate constants were calculated using Rice-Ramsperger-Kassel-Marcus theory with a one-dimensional master equation. A number of studies have highlighted the fact that C intermediate species play a role in polyaromatic hydrocarbon formation and that a fuel's chemical structure can be key in understanding the intermediate species formed during fuel decomposition. Rate constant recommendations for both Ḣ atom addition to, and H-atom abstraction by Ḣ atoms from, linear and branched alkenes have subsequently been proposed by incorporating our earlier work on 1- and 2-pentene, and these can be used in mechanisms of larger alkenes for which calculations do not exist. The current set of rate constants for the reactions of Ḣ atoms with both linear and branched C alkenes, including their chemically activated pathways, are the first available in the literature of any reasonable fidelity for combustion modeling and are important for gasoline mechanisms. Validation of our theoretical results with pyrolysis experiments of 2-methyl-1-butene, 2-methyl-2-butene, and 3-methyl-1-butene at 2 bar in a single pulse shock tube (SPST) were carried out, with satisfactory agreement observed.
本文给出了氢原子加成到2-甲基-1-丁烯、2-甲基-2-丁烯和3-甲基-1-丁烯以及从这些烯烃上夺取氢原子，随后发生β-断裂和氢原子转移反应的综合势能面（PES）。利用一系列等键反应确定生成焓，计算了ĊH势能面（PES）上各物种的热化学参数随温度（298 - 2000 K）的变化。采用一维主方程的赖斯-拉姆齐格-卡斯尔-马库斯理论计算了高压极限速率常数和压力依赖速率常数。许多研究强调了碳中间物种在多环芳烃形成中起作用这一事实，并且燃料的化学结构对于理解燃料分解过程中形成的中间物种可能是关键的。通过结合我们早期对1-戊烯和2-戊烯的研究工作，随后提出了氢原子加成到直链和支链烯烃以及从直链和支链烯烃夺取氢原子的速率常数建议，这些建议可用于不存在计算结果的较大烯烃的反应机理中。目前关于氢原子与直链和支链碳烯烃反应的速率常数集，包括其化学活化途径，是文献中首次出现且具有任何合理精度可用于燃烧建模的，对于汽油反应机理很重要。我们用2-甲基-1-丁烯、2-甲基-2-丁烯和3-甲基-1-丁烯在单脉冲激波管（SPST）中2 bar压力下的热解实验对理论结果进行了验证，观察到了令人满意的一致性。
