Temperature and pressure dependence of the rate coefficient for the reaction between ClO and CH3O2 in the gas-phase.
Temperature and pressure dependence of the rate coefficient for the reaction between ClO and CH3O2 in the gas-phase.
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DOI：
10.1039/c2cp22834c
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发表时间：
2012-02
期刊：
影响因子：
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通讯作者：
K. Leather;A. Bacak;R. Wamsley;A. Archibald;Alexander Husk;D. Shallcross;C. Percival
中科院分区：
文献类型：
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作者：
K. Leather;A. Bacak;R. Wamsley;A. Archibald;Alexander Husk;D. Shallcross;C. Percival
使用湍流技术和化学电离质谱检测系统对 CH(3)O(2) + ClO 反应进行了温度和压力动力学研究。 CH(3)O(2) + ClO 反应的总速率系数得到了阿伦尼乌斯表达式： k(10)(T) = (1.96(−0.24)(+0.28)) × 10(-11) exp[(-626 ± 35)/T] cm(3) molecular(-1) s(-1) 其中与速率系数相关的不确定性在一个标准偏差水平下给出。在一定的压力 (100-200 Torr) 和温度 (298-223 K) 范围内，没有观察到压力依赖性。与之前的两项低温研究相比，在较低温度下测得的较小速率系数被认为是由于二次化学反应的减少和反应物检测方面更高的灵敏度而产生的（因此采用了低得多的初始浓度）。这些新数据将极地平流层中涉及 CH(3)O(2) + ClO 反应的臭氧损失循环的有效性降低了约 1.5 倍，并限制了该反应对对流层热带和热带外清洁海洋环境的重要性。
A temperature and pressure kinetic study for the CH(3)O(2) + ClO reaction has been performed using the turbulent flow technique with a chemical ionisation mass spectrometry detection system. An Arrhenius expression was obtained for the overall rate coefficient of CH(3)O(2) + ClO reaction: k(10)(T) = (1.96(−0.24)(+0.28)) × 10(-11) exp[(-626 ± 35)/T] cm(3) molecule(-1) s(-1) where the uncertainty associated with the rate coefficient is given at the one standard deviation level. Over a range of pressure (100-200 Torr) and temperature (298-223 K) no pressure dependence is observed. The smaller rate coefficients measured at lower temperatures compared with both previous low temperature studies are believed to arise through the reduction of secondary chemistry and greater sensitivity in terms of reactant detection (hence much lower initial concentrations were employed). These new data reduce the effectiveness of ozone loss cycles involving reaction of CH(3)O(2) + ClO in the polar stratosphere by around a factor of 1.5 and restrict the importance of the reaction to the tropical and extra-tropical clean marine environments in the troposphere.