A theoretical study of the oxidation of Hg0 to HgBr2 in the troposphere
A theoretical study of the oxidation of Hg0 to HgBr2 in the troposphere
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DOI：
10.1021/es034680s
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发表时间：
2004-03-15
影响因子：
11.4
通讯作者：
Skov, H
中科院分区：
文献类型：
--
作者：
Goodsite, ME;Plane, JMC;Skov, H
元素汞（Hg-0）氧化为二价气态二溴化汞（HgBr 2），这被认为是春季北极汞耗竭事件中Hg-0的去除原因。本文通过对相关速率系数的理论计算，探讨了这一过程的机理。Rice-Ramsberger-Kassel-Marcus（RRKM）理论，连同从头计算的量子计算，在需要时，被用来估计以下内容：重组率系数的汞与溴，碘，和O;的热离解率系数的HgBr;和重组率系数的HgBr与溴，碘，OH，和O-2。一种机制的基础上的初始重组的汞与溴，其次是另外的第二个自由基（Br，I，或OH）的竞争与热离解的HgBr，是能够解释所观察到的速率的Hg-0去除，无论是在北极枯竭事件和低纬度地区。
The oxidation of elemental mercury (Hg-0) to the divalent gaseous mercury dibromide (HgBr2) has been proposed to account for the removal of Hg-0 during depletion events in the springtime Arctic. The mechanism of this process is explored in this paper by theoretical calculations of the relevant rate coefficients. Rice-Ramsberger-Kassel-Marcus (RRKM) theory, together with ab initio quantum calculations where required, are used to estimate the following: recombination rate coefficients of Hg with Br, I, and O; the thermal dissociation rate coefficient of HgBr; and the recombination rate coefficients of HgBr with Br, I, OH, and O-2. A mechanism based on the initial recombination of Hg with Br, followed by the addition of a second radical (Br, I, or OH) in competition with thermal dissociation of HgBr, is able to account for the observed rate of Hg-0 removal, both in Arctic depletion events and at lower latitudes.