摘要
本文采用CCSD(T)/aug-cc-pVTZ//B3LYP/6-311+G(2df,2p)方法构建了HO_2+ClO反应体系的单、三重态反应势能剖面,并对该反应主通道的速率常数进行了计算研究.结果表明,HO_2+ClO反应中存在4条抽氢通道R1(HOCl+~1O_2)、R2(HOCl+~3O_2)、R3(HCl+~1O_3)和R4(HCl+~3O_3)以及2条抽氧通道R5(OOCl+HO)和R6(OClO+HO),其中抽氢通道R2(HOCl+~3O_2)和R3(HCl+1O3)的能垒比其它四个通道的能垒降低了9.08~42.90kcal·mol-1,是标题反应的优势通道.采用传统过渡态理论并结合Wigner校正对优势通道R2(HOCl+~3O_2)和R3(HCl+~1O_3)在240~425K范围内的速率常数进行了计算.计算结果表明,通道R2(HOCl+3 O2)的速率常数比R3(HCl+~1O_3)的对应值大了3~5个数量级,表明标题反应的速率主要取决于通道R2(HOCl+~3O_2).此外在298 K时,通道R2(HOCl+3O2)的速率常数为2.76×10-15 cm3·molecule-1·s-1,与实验值较为吻合.
The mechanism for the reaction of C1O with HO2 was investigated at the CCSD(T)/aug-cc- pVTZ//B3LYP/6-311+G(2df,2p) level on both the singlet and triplet potential energy surfaces, along with the rate constant calculations of the major channel. The results show that there are four hydrogen abstraction channels, namely channel R1 (HOCI+1O2), channel R2 (HOCI+3O2), channel R3 (HC1 +1O3) and channel R4 (HC1+3O3), as well as two oxygen abstraction channels, labeled as channel R5 (OOCI+HO) and channel R6 (OC1O+HO) in the HO2 +C10 reaction. The energy barrier of the hydro- gen abstraction channels R2 (HOCI+3O2) and R3 (HC1+1O3) are lower by 9.08~42.90 kcal · mo1-1 than those of the other four channels. The rate constants of the favorable channels R2 (HOC1+3O2) and channel R3 (HC1+1O3) in the 240~425 K range were evaluated by means of the classical transition state theory (TST) with Wigner tunneling correction. The calculated results show that the rate constant of channel R2 (HOC1+3O2) is larger by 3~5 orders of magnitude, indicating that the total rate constants of HO2 +C1O reaction mainly lie on the contribution oF channel R2 (HOC1+3 O2). Besides, the rate con- stant of channel R2 (HOC1+ 3O2 ) is 2.76 ~ 10-15 cma o molecule-1 · s-1 at 298 K, in excellent agreement with experimental value.
作者
王睿
凤旭凯
贾子龙
邵先钊
张强
张田雷
WANG Rui;FENG Xu-Kai;J IA Zi-Long;SHAO Xian-Zhao;ZHANG Qiang;ZHANG Tian-Lei(Shaanxi Key Laboratory of Catalysis, School of Chemical & Environmental Sciences, Shaanxi University of Technology, Hanzhong 723000, China;College of Chemistry & Materials science, Northwest University, Xiran 710127, China)
出处
《四川大学学报(自然科学版)》
CAS
CSCD
北大核心
2018年第3期585-593,共9页
Journal of Sichuan University(Natural Science Edition)
基金
国家自然科学基金(21603132
21503125
21502109)
陕西省教育厅项目(15JK1138
15JK1161)
陕西理工学院科研计划项目(SLGQD13(2)-3
SLGQD13(2)-4)
关键词
HO2
CLO
势能面
反应机理
速率常数
HO2
CIO
Potential energy surface
Reaction mechanism
Rate constant