Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I. Virtasen aukio 1), 00014 Helsinki, Finland.
Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok krt. 2, Budapest H-1117, Hungary.
J Phys Chem A. 2023 Feb 9;127(5):1302-1313. doi: 10.1021/acs.jpca.2c07780. Epub 2023 Jan 25.
We have used laser-photolysis - photoionization mass-spectrometry to measure the rate coefficient for the reaction between ethyl radical and molecular oxygen as a function of temperature (190-801 K) and pressure (0.2-6 Torr) under pseudo-first-order conditions ([He] ≫ [O] ≫ [CH]). Multiple ethyl precursor, photolysis wavelength, reactor material, and coating combinations were used. We reinvestigated the temperature dependence of the title reaction's rate coefficient to resolve inconsistencies in existing data. The current results indicate that some literature values for the rate coefficient may indeed be slightly too large. The experimental work was complemented with master equation simulations. We used the current and some previous rate coefficient measurements to optimize the values of key parameters in the master equation model. After optimization, the model was able to reproduce experimental falloff curves and CH + HO yields. We then used the model to perform simulations over wide temperature (200-1500 K) and pressure (10-10 bar) ranges and provide the results in PLOG format to facilitate their use in atmospheric and combustion models.
我们使用激光光解-光电离质谱法，在准一级条件下（[He]≫[O]≫[CH]），测量了乙基自由基与氧气分子反应的速率系数随温度（190-801 K）和压力（0.2-6 托）的函数关系。我们使用了多种乙基前体、光解波长、反应器材料和涂层组合。我们重新研究了标题反应速率系数的温度依赖性，以解决现有数据中的不一致性。目前的结果表明，某些文献中的速率系数值可能确实略大。实验工作得到了主方程模拟的补充。我们使用当前和一些以前的速率系数测量值来优化主方程模型中的关键参数值。优化后，该模型能够重现实验的下降曲线和 CH + HO 的产率。然后，我们使用该模型在宽温度（200-1500 K）和压力（10-10 巴）范围内进行模拟，并以 PLOG 格式提供结果，以方便它们在大气和燃烧模型中的使用。
