ARTICLES: Theoretical Study on Destruction Mechanism of 2,3,7,8-TCDD by O3 and NO3
ARTICLES: Theoretical Study on Destruction Mechanism of 2,3,7,8-TCDD by O3 and NO3
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DOI：
10.1088/1674-0068/23/03/303-309
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发表时间：
2010-06
影响因子：
1
通讯作者：
Zhihua Wang;Z. Wen;Jiang-rong Xu;Junhu Zhou;K. Cen
中科院分区：
文献类型：
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作者：
Zhihua Wang;Z. Wen;Jiang-rong Xu;Junhu Zhou;K. Cen
为了提高二恶英的降解效率和开发新的二恶英控制技术，采用量子化学计算方法研究了O3和NO3对2,3,7,8-四氯二henzo-对二恶英（2,3,7,8- tcdd）的降解机理。对于涉及的反应，基于B3LYP/ 6-31G (d)方法的几何优化，对微观反应过程进行了详细的分析和描述。同时，在MP2/6-311G (d,p)//B3LYP/ 6-31G (d)水平上计算反应活化能。构型分析表明，O3和NO3能以两种不同的方式破坏2,3,7,8- tcdd。O3对2,3,7,8- tcdd的破坏是通过O3的加入和C = C的裂解进行的，而NO3对2,3,7,8- tcdd的破坏是通过NO3取代氯进行的。计算结果表明，NO3对2,3,7,8- tcdd的破坏反应活化能（267.48 kJ/mol）远大于O3对2,3,7,8- tcdd的破坏反应活化能（51.20 kJ/mol）。这表明O3对2,3,7,8- tcdd的破坏比NO3对2,3,7,8- tcdd的破坏要有效得多。讨论了NO3对2,3,7,8- tcdd的破坏反应活化能大的原因。
In order to improve the destruction efficiency of dioxins and also for developing new dioxin control technology, the destruction mechanisms of 2,3,7,8-tetrachlorodihenzo-p-dioxin (2,3,7,8-TCDD) by O3 and NO3, were investigated employing quantum chemical calculations. For involved reactions, the microcosmic reaction processes were analyzed and depicted in detail based on geometry optimizations made by the B3LYP/6–31G(d) method. At the same time, the reaction activation energies were also calculated at the MP2/6–311G(d,p)//B3LYP/6–31G(d) level. Configuration analysis indicated that 2,3,7,8-TCDD could be destroyed by O3 and NO3 in two different ways. The destruction of 2,3,7,8-TCDD by O3 proceeded via the addition of O3 and the cleavage of C = C while the destruction of 2,3,7,8-TCDD by NO3 proceeded via the substitution of chlorine by NO3. Calculated results show that, the activation energy of the destruction reaction of 2,3,7,8-TCDD by NO3 (267.48 kJ/mol) is much larger than that of the destruction reaction of 2,3,7,8-TCDD by O3 (51.20 kJ/mol). This indicated that the destruction of 2,3,7,8-TCDD by O3 is much more efficient than that of 2,3,7,8-TCDD by NO3. The reason why the activation energy for the destruction reaction of 2,3,7,8-TCDD by NO3 is so large, is also discussed.