Yield of Formyl Radical from the Vinyl+O_2 Reaction
Yield of Formyl Radical from the Vinyl+O_2 Reaction
复制标题
乙烯基O_2反应甲酰自由基的产率
DOI：
10.1002/kin.20823
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Akira Matsugi and Akira Miyoshi
中科院分区：
文献类型：
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作者：
M. Futakawa;T. Naoe;H. Kogawa;K. Haga;K. Okita;Akira Matsugi and Akira Miyoshi
利用脉冲激光光解/光腔衰荡光谱技术研究了室温下乙烯基自由基（C2 H3）与O2反应生成的甲酰基自由基（HCO）.测得C2 H3 + O2和HCO + O2反应的速率常数分别为（8.60 ± 0.87）× 10− 12和（5.55 ± 1.00）× 10− 12 cm 3 molecule − 1 s −1，与前人的研究结果一致. HCO自由基的产率为ε（HCO）= 0.222 ± 0.066，在10-100 Torr压力范围内与压力无关。Rice-Ramsperger-Kassel-Marcus计算结合先验能量分布模型可以再现实验HCO‐自由基产率，并表明C2 H3 + O2反应中形成的HCO自由基的相当一部分迅速解离为H + CO。在总压为1 Torr时观察到HCO自由基的第一CO‐伸缩激发态HCO（0，0，1）;通过包括热HCO自由基的弛豫的动力学模拟，其时间曲线令人满意地再现。这些实验、理论和模拟结果为C2 H3 + O2反应中形成的热HCO自由基的迅速解离提供了坚实的证据。给出了外推至更高温度和更宽压力范围的产品特定速率常数。建议的燃烧模拟机制的影响进行了讨论。
The yield of formyl (HCO) radical from the reaction of vinyl (C2H3) radical with O2has been investigated by using a pulsed laser photolysis/cavity ring‐down spectroscopy technique at room temperature. The rate constants for the C2H3+ O2and HCO + O2reactions were measured to be (8.60 ± 0.87) × 10−12and (5.55 ± 1.00) × 10−12cm3molecule−1s−1, respectively, which were consistent with preceding studies. The yield of HCO radical was determined to beϕ(HCO) = 0.222 ± 0.066, and it was independent of pressure in the pressure range 10–100 Torr with He or N2buffer. The Rice–Ramsperger–Kassel–Marcus calculation combined with a prior energy distribution model could reproduce the experimental HCO‐radical yield and indicated that a significant portion of HCO radicals formed in the C2H3+ O2reaction promptly dissociated to H + CO. The first CO‐stretch excited state of HCO radical, HCO(0,0,1), was observed at the total pressure of 1 Torr; the time profiles of which were satisfactory reproduced by a kinetic simulation including the relaxation of hot HCO radicals. These experimental, theoretical, and modeling results provide solid evidence for the prompt dissociation of hot HCO radicals formed in the C2H3+ O2reaction. The product‐specific rate constants that extrapolated to higher temperature and wider pressure ranges are presented. Implications of the suggested mechanism for combustion modeling are also discussed.