Liu Dapeng, Khaled Fethi, Giri Binod R, Assaf Emmanuel, Fittschen Christa, Farooq Aamir
Clean Combustion Research Center, King Abdullah University of Science and Technology , Thuwal 23955, Kingdom of Saudi Arabia.
Université Lille , CNRS, UMR 8522 - PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France.
J Phys Chem A. 2017 Feb 9;121(5):927-937. doi: 10.1021/acs.jpca.6b10576. Epub 2017 Jan 27.
Reaction rate coefficients for the reaction of hydroxyl (OH) radicals with nine large branched alkanes (i.e., 2-methyl-3-ethyl-pentane, 2,3-dimethyl-pentane, 2,2,3-trimethylbutane, 2,2,3-trimethyl-pentane, 2,3,4-trimethyl-pentane, 3-ethyl-pentane, 2,2,3,4-tetramethyl-pentane, 2,2-dimethyl-3-ethyl-pentane, and 2,4-dimethyl-3-ethyl-pentane) are measured at high temperatures (900-1300 K) using a shock tube and narrow-line-width OH absorption diagnostic in the UV region. In addition, room-temperature measurements of six out of these nine rate coefficients are performed in a photolysis cell using high repetition laser-induced fluorescence of OH radicals. Our experimental results are combined with previous literature measurements to obtain three-parameter Arrhenius expressions valid over a wide temperature range (300-1300 K). The rate coefficients are analyzed using the next-nearest-neighbor (N-N-N) methodology to derive nine tertiary (T, T, T, T, T, T, T, T, and T) site-specific rate coefficients for the abstraction of H atoms by OH radicals from branched alkanes. Derived Arrhenius expressions, valid over 950-1300 K, are given as (the subscripts denote the number of carbon atoms connected to the next-nearest-neighbor carbon): T = 1.80 × 10 exp(-2971 K/T) cm molecule s; T = 9.36 × 10 exp(-3024 K/T) cm molecule s; T = 4.40 × 10 exp(-4162 K/T) cm molecule s; T = 1.47 × 10 exp(-3587 K/T) cm molecule s; T = 6.06 × 10 exp(-3010 K/T) cm molecule s; T = 3.98 × 10 exp(-1617 K/T) cm molecule s; T = 9.08 × 10 exp(-3661 K/T) cm molecule s; T = 6.74 × 10 exp(-7547 K/T) cm molecule s; T = 3.47 × 10 exp(-1802 K/T) cm molecule s.
利用激波管和紫外区域的窄线宽OH吸收诊断技术，在高温（900 - 1300 K）下测量了羟基（OH）自由基与九种大支链烷烃（即2 - 甲基 - 3 - 乙基戊烷、2,3 - 二甲基戊烷、2,2,3 - 三甲基丁烷、2,2,3 - 三甲基戊烷、2,3,4 - 三甲基戊烷、3 - 乙基戊烷、2,2,3,4 - 四甲基戊烷、2,2 - 二甲基 - 3 - 乙基戊烷和2,4 - 二甲基 - 3 - 乙基戊烷）反应的速率系数。此外，在光解池中使用OH自由基的高重复率激光诱导荧光对这九种速率系数中的六种进行了室温测量。我们将实验结果与先前文献中的测量结果相结合，得到了在宽温度范围（300 - 1300 K）内有效的三参数阿伦尼乌斯表达式。使用次近邻（N - N - N）方法分析速率系数，以得出OH自由基从支链烷烃中提取H原子的九个叔位（T, T, T, T, T, T, T, T, 和T）位点特异性速率系数。在950 - 1300 K范围内有效的推导阿伦尼乌斯表达式如下（下标表示与次近邻碳原子相连的碳原子数）：T = 1.80 × 10 exp(-2971 K/T) cm³ molecule⁻¹ s⁻¹；T = 9.36 × 10 exp(-3024 K/T) cm³ molecule⁻¹ s⁻¹；T = 4.40 × 10 exp(-4162 K/T) cm³ molecule⁻¹ s⁻¹；T = 1.47 × 10 exp(-3587 K/T) cm³ molecule⁻¹ s⁻¹；T = 6.06 × 10 exp(-3010 K/T) cm³ molecule⁻¹ s⁻¹；T = 3.98 × 10 exp(-1617 K/T) cm³ molecule⁻¹ s⁻¹；T = 9.08 × 10 exp(-3661 K/T) cm³ molecule⁻¹ s⁻¹；T = 6.74 × 10 exp(-7547 K/T) cm³ molecule⁻¹ s⁻¹；T = 3.47 × 10 exp(-1802 K/T) cm³ molecule⁻¹ s⁻¹。
