OH自由基引发的2,3,7,8-四氯代二苯并呋喃降解机理的理论研究  

The mechanism study of the degradation reaction of 2,3,7,8-TCDF initiated by OH radical

作　　者：张坤[1] 孙胜敏[1] 张辉[1] 

机构地区：[1]哈尔滨理工大学化学与环境工程学院,黑龙江哈尔滨150080

出　　处：《东北师大学报（自然科学版）》2014年第4期103-109,共7页Journal of Northeast Normal University(Natural Science Edition)

基　　金：教育部博士点专项基金资助项目(20112303110005);黑龙江杰出青年基金资助项目(JC201206)

摘　　要：对2,3,7,8-四氯代二苯并呋喃(2,3,7,8-TCDF)的OH自由基加成反应机理以及后续的单分子降解反应机理进行了理论研究.从微观反应动力学角度解释了常温下2,3,7,8-TCDF作为二噁英类物质难降解的根本原因,并阐述了其在高温下的单分子降解反应机理.采用密度泛函理论,计算得到了反应势能面上各稳定点的几何结构,同时完成了简谐振动频率分析,并通过内禀反应坐标理论计算出各反应通道的最低能量路径.结果表明,OH自由基容易加成到2,3,7,8-TCDF上,但后续的降解反应的能垒过高,因此2,3,7,8-TCDF降解反应只能在高温下进行.In this paper,the mechanism on the addition reaction of 2,3,7,8-TCDF with OH radical and subsequent unimolecular decomposition reaction are investigated by theoretical calculation.The recalcitrance of 2,3,7,8-TCDF at room temperature is explained from the perspective of microscopic kinetic,and the mechanism of unimolecular degradation reaction at high temperature is expounded simultaneously.In this study,the density functional theory is employed to calculate the equilibrium geometries of the stable points on the reaction potential energy surface,and the harmonic vibration frequencies analysis is completed.The minimum energy path（MEP）is obtained by The intrinsic reaction coordinate（IRC）theory.The study results show that the OH radical addition reaction of2,3,7,8-TCDF can occur easily,but the degradation reaction of 2,3,7,8-TCDF can only happen at high temperatures due to the high energy barrier of subsequent unimolecular degradation reaction.

关 键 词：2 3 7 8-四氯代二苯并呋喃 二噁英 过渡态 降解机理 

分 类 号：O641.1[理学—物理化学]