Gas-Phase Br2 Production in Heterogeneous Reactions of Cl2, HOCl, and BrCl with Halide−Ice Surfaces
Gas-Phase Br2 Production in Heterogeneous Reactions of Cl2, HOCl, and BrCl with Halide−Ice Surfaces
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DOI：
10.1021/jp001155w
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发表时间：
2000-07
影响因子：
2.9
通讯作者：
Amy K. Huff and;J. Abbatt
中科院分区：
文献类型：
--
作者：
Amy K. Huff and;J. Abbatt
为了评估可能将气相Br2释放到北极边界层的不同非均质机制的相对重要性，在实验室中研究了Cl2、HOCl2和BrCl3与含卤化物冰面的相互作用。实验结果来自于使用与质谱仪耦合的涂层壁低压流动管的实验结果。气相反应几率是根据233K时Cl2、HOCl2或BrCl1在溴冰表面和248K时氯/溴冰表面上的一级损失来计算的，在所有情况下反应都相对较快，主要产物是气相Br2。为了确定影响这些反应动力学的主要因素，在一系列温度、冰中氢离子浓度和冰中卤化物浓度范围内进行了实验。Cl2反应几率随着冰膜中溴浓度的增加而增加，最高可达3%左右。在这一点上，冰面是完全饱和的。
In order to evaluate the relative importance of different heterogeneous mechanisms that may release gas-phase Br2 into the Arctic boundary layer, interactions of Cl2, HOCl, and BrCl with halide-containing ice surfaces were studied in the laboratory. Results are presented from experiments using a coated-wall, low-pressure flow tube coupled to a mass spectrometer. Gas-surface reaction probabilities were calculated from the first-order loss of Cl2, HOCl, or BrCl on bromide-ice surfaces at 233 K and on chloride/bromide-ice surfaces at 248 K. In all cases, the reactions were relatively fast, and the primary product was gas-phase Br2. To determine the main factors that influence the kinetics of these reactions, experiments were conducted over a range of temperatures, hydrogen ion concentrations in ice, and halide concentrations in ice. Cl2 reaction probability increases with increasing bromide concentration in the ice film, up to approximately 3% bromide. At this point, the ice surface is completely saturated w...