Experimental and Theoretical Studies of Rate Coefficients for the Reaction O(3P) + C2H5OH at High Temperatures

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• 作者：Chih-Wei Wu ; Yuan-Pern Lee ; Shucheng Xu ; M. C. Lin
• 刊名：Journal of Physical Chemistry A
• 出版年：2007
• 出版时间：July 26, 2007
• 年：2007
• 卷：111
• 期：29
• 页码：6693 - 6703
• 全文大小：352K
• 年卷期：v.111,no.29(July 26, 2007)
• ISSN：1520-5215

文摘

Rate coefficients of the reaction O(³P) + C₂H₅OH in the temperature range 782-1410 K were determinedusing a diaphragmless shock tube. O atoms were generated by photolysis of SO₂ at 193 nm with an ArFexcimer laser; their concentrations were monitored via atomic resonance absorption. Our data in the range886-1410 K are new. Combined with previous measurements at low temperature, rate coefficients determinedfor the temperature range 297-1410 K are represented by the following equation: k(T) = (2.89 ± 0.09) ×10^-16T^1.62 exp[-(1210 ± 90)/T] cm³ molecule^-1 s^-1; listed errors represent one standard deviation in fitting.Theoretical calculations at the CCSD(T)/6-311+G(3df, 2p)//B3LYP/6-311+G(3df) level predict potentialenergies of various reaction paths. Rate coefficients are predicted with the canonical variational transitionstate (CVT) theory with the small curvature tunneling correction (SCT) method. Reaction paths associatedwith trans and gauche conformations are both identified. Predicted total rate coefficients, 1.60 × 10^-22T^3.50exp(16/T) cm³ molecule^-1 s^-1 for the range 300-3000 K, agree satisfactorily with experimental observations.The branching ratios of three accessible reaction channels forming CH₃CHOH + OH (1a), CH₂CH₂OH +OH (1b), and CH₃CH₂O + OH (1c) are predicted to vary distinctively with temperature. Below 500 K, reaction1a is the predominant path; the branching ratios of reactions 1b,c become ~40% and ~11%, respectively, at2000 K.