Dillon T J, Hölscher D, Sivakumaran V, Horowitz A, Crowley J N
Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany.
Phys Chem Chem Phys. 2005 Jan 21;7(2):349-55. doi: 10.1039/b413961e.
Absolute rate coefficients for the reaction of hydroxyl radicals (HO) with methanol, HO + CH3OH --> products (R1), and with ethanol, HO + C2H5OH --> products (R2) were measured over a range of temperatures using pulsed laser photolytic generation of HO coupled to its time resolved detection by pulsed laser induced fluorescence. The accuracy of the rate constants obtained was enhanced by on-line optical absorption measurements of the alcohol concentration. The temperature dependence of the rate coefficients is given by: k1(210-351 K) = 6.67 x 10(-18) T2 exp(140/T) cm3 molecule(-1) s(-1) with a rate coefficient at room temperature of (9.3 +/- 0.7) x 10(-13) cm3 molecule(-1) s(-1). For k2 we obtained: k2(216-368 K) = 4.0 x 10(-12) exp(-42/T) and a room temperature rate coefficient of (3.35 +/- 0.17) x 10(-12) cm3 molecule(-1) s(-1). The total error (at 95% confidence) associated with the rate coefficients derived from the expressions describing the temperature dependence is estimated as 7% at all temperatures. The present results, which extend the database on these reactions to cover temperatures relevant for the upper troposphere, are compared to previously published measurements, and values of k1 and k2 are recommended for atmospheric modelling.
利用脉冲激光光解产生羟基自由基（HO）并通过脉冲激光诱导荧光对其进行时间分辨检测，在一系列温度范围内测量了羟基自由基（HO）与甲醇反应（HO + CH₃OH → 产物，反应R1）以及与乙醇反应（HO + C₂H₅OH → 产物，反应R2）的绝对速率系数。通过对醇浓度进行在线光吸收测量，提高了所得速率常数的准确性。速率系数与温度的关系如下：k1(210 - 351 K) = 6.67 x 10⁻¹⁸ T² exp(140/T) cm³ molecule⁻¹ s⁻¹，室温下的速率系数为(9.3 ± 0.7) x 10⁻¹³ cm³ molecule⁻¹ s⁻¹。对于k2，我们得到：k2(216 - 368 K) = 4.0 x 10⁻¹² exp(-42/T)，室温速率系数为(3.35 ± 0.17) x 10⁻¹² cm³ molecule⁻¹ s⁻¹。在所有温度下，由描述温度依赖性的表达式得出的速率系数相关的总误差（95%置信度）估计为7%。将本研究结果（该结果扩展了这些反应的数据库，涵盖了与对流层上部相关的温度范围）与先前发表的测量结果进行了比较，并推荐了k1和k2的值用于大气建模。
