H_2O_2与HS气相抽氢、抽氧反应机理及速率常数的理论研究  

Theoretical studies of the H_2O_2+ HS reaction mechanism and rate constants in the gas phase

作　　者：王睿[1] 安一鸣 陈佳 杨晨 张鹏[1] 徐晖[2] 

机构地区：[1]陕西理工学院化学与环境科学学院陕西省催化基础与应用重点实验室,陕西汉中723000 [2]陕西省汉中市产品质量监督检验所,陕西汉中723000

出　　处：《陕西理工学院学报（自然科学版）》2015年第6期33-38,共6页Journal of Shananxi University of Technology:Natural Science Edition

基　　金：陕西理工学院科研基金资助项目(SLGQD13(2)-3;SLGQD13(2)-4)

摘　　要：采用CCSD（T）/aug-cc-p VTZ//B3LYP/6-311＋G（2df,2p）方法构建了H2O2与HS反应体系的双重态反应势能剖面,并在此基础上对各通道的速率常数进行了计算。研究结果表明,由于H2O2接近HS自由基的方式不同,H2O2与HS反应有两个不同的反应通道,相应的生成HO2与H2S（通道R1）和HSOH＋OH（通道R2）产物。通道R1和R2的表观活化能较为接近,分别为14.25~15.40 kcal/mol和13.91 kcal/mol。利用经典过渡态理论（TST）并结合Wigner矫正模型计算了216.69~298.15 K温度范围内H2O2与HS反应的速率常数。计算结果显示,通道R1的反应速率常数kR1为2.43×10^-21~4.20×10^-20cm^3/（molecule·s）,比相同温度下反应通道R2的速率常数kR2大了2~4个数量级,表明在216.69~298.15 K温度范围内,H2O2与HS反应的总速率主要取决于反应通道R1。The reaction mechanism and rate constant between the H2O2＋ HS reaction has been investigated theoretically at the CCSD（ T） / aug-cc-p VTZ / / B3 LYP /6-311 ＋ G（ 2df,2p） level of theory. The results show that the H2O2＋ HS reaction has two kinds of reaction channels depending on how the H2O2 radical approached HS,corresponding to the formation of HO2＋ H2S（ Channel R1） and HSOH ＋ OH（ Channel R2）.The apparent activation energy for Channel R1 and Channel R2 is close to each other,corresponding to14. 25 ~ 15. 40 kcal / mol and 13. 91 kcal / mol. Additionally,to estimate the importance of the two processes in the atmosphere,rate constants of Channels R1 and R2 are evaluated using the conventional transition state theory with Wigner tunneling correction. The result shows that the rate constant of Channel R1 is 2. 43 × 10^- 21~4. 20 × 10^- 20cm^3/（ molecule·s）,which is much larger by 2 ~ 4 orders of magnitude than the corresponding value of Channel R2,indicating that almost only the Channel of R1 reaction takes place in the calculation of temperature range under atmospheric conditions.

关 键 词：H2O2 HS 势能面 反应机理 速率常数 

分 类 号：O643.322[理学—物理化学]