高等学校化学学报 ›› 2014, Vol. 35 ›› Issue (10): 2191.doi: 10.7503/cjcu20140310

• 物理化学 • 上一篇    下一篇

单个水分子对HO2+H2S反应主通道影响的理论研究

许琼1(), 王睿1, 张田雷1, 张浩林1, 王志银1, 王竹青2   

  1. 1. 陕西理工学院化学与环境科学学院, 汉中 723001
    2. 山东省科学院海洋仪器仪表研究所, 山东省海洋环境监测技术重点实验室, 青岛 266001
  • 收稿日期:2014-04-04 出版日期:2014-10-10 发布日期:2014-09-30
  • 作者简介:联系人简介: 许琼, 女, 副教授, 主要从事理论与计算化学研究. E-mail: xuq@snut.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 21207081)、 陕西省教育厅科研项目(批准号: 12JK0625)、 陕西理工学院科研计划资助项目(批准号: SLGQD13(2)-3, SLGQD13(2)-4)和山东省自然科学基金(批准号: ZR2012DQ001)资助

Theoretical Studies on the Single Water Molecule’s Effect on the Main Channel of H2S+HO2 Reaction

XU Qiong1,*(), WANG Rui1, ZHANG Tianlei1, ZHANG Haolin1, WANG Zhiyin1, WANG Zhuqing2   

  1. 1. School of Chemical & Environment Science, Shaanxi University of Technology, Hanzhong 723001, China
    2. Shandong Provincial Key Laboratory of Ocean Environment Monitoring Technology, Shandong Academy of Sciences Institute of Oceanographic Instrumentation, Qingdao 266001, China
  • Received:2014-04-04 Online:2014-10-10 Published:2014-09-30
  • Contact: XU Qiong E-mail:xuq@snut.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.21207081), the Education Department of Shaanxi Provincial Government Research Project, China(No.12JK0625), the Funds of Research Programs of Shaanxi University of Technology, China(Nos SLGQD13(2)-3, SLGQD13(2)-4) and the Natural Science Foundation of Shandong Province, China(No.ZR2012DQ001)

摘要:

采用CCSD(T)/aug-cc-pVTZ//B3LYP/6-311+G(2df,2p)方法对HO2+H2S反应及单分子水参与其主通道的微观机理和速率常数进行了研究. 结果表明, HO2+H2S反应主通道为生成产物为H2O2+HS的通道, 其表观活化能为14.94 kJ/mol. 考虑单分子水对主产物通道的影响发现, 所得的势能面比无水参与的反应复杂得多, 经历了H2O…HO2+H2S(RW1), HO2…H2O+H2S(RW2)和H2O…H2S+HO2(RW3)3个通道, RW1~RW6共6个路径. 其中通道RW1是水分子参与HO2+H2S反应主通道的优势通道. 在216.7~298.2 K温度范围内通道RW1的有效速率常数呈现出正温度系数效应, 在298 K时, k'RW1/ktotal达到54.2%, 表明在实际大气环境中水分子对HO2+H2S反应的主通道具有明显影响.

关键词: HO2+H2S反应, 水催化, 反应机理, 过渡态理论

Abstract:

The reaction mechanism and rate constant for the major channel between HO2 and H2S, without and with a water molecule, were investigated theoretically at the CCSD(T)/aug-cc-pVTZ// B3LYP/6-311+G(2df, 2p) level. The goal of the present investigation is to determine how the single water molecule can affect the reaction mechanisms and kinetics for the major channel of HO2+H2S reaction and estimate the importance of water effects on the major channel of HO2+H2S reaction. The calculated results show that the HO2+H2S reaction mainly occurs through the channel of H2O2+HS formation with the apparent activation energy of 14.94 kJ/mol. When one water molecule is added, the reaction mechanism of the major channel becomes quite complex yielding three different reaction channels of H2O…HO2+H2S(RW1), HO2…H2O+H2S(RW2) and H2O…H2S+HO2(RW2). For single water-catalyzed the major channel of HO2+H2S reaction, channel RW1 is dominant and path RW1 is the most favorable. Additionally, to estimate the importance of channel RW1 in the atmosphere, its rate constant is evaluated using the conventional transition state theory with Wigner tunneling correction. The calculated results show that the effective rate constant of path RW1 increases with the temperature increases. At 298 K, the value of k'RW1/ktotal is up to 54.2%, indicating that the single water molecule has a obvious effect on the major channel of atmospheric reaction of HO2+H2S. The present study provides further insight into water effects in the atmospheric chemistry.

Key words: HO2+H2S reaction, Water-catalyzed, Reaction mechanism, Transition state theory

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