Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (6): 1061-1070.doi: 10.3866/PKU.WHXB201404032


Theoretical Study on the effect of a Single Water Molecule on the H2O2+Cl Gas Reaction

XU Qiong1, ZHANG Tian-Lei1, Lü Wen-Bin1, WANG Rui1, WANG Zhi-Yin1, WANG Wen-Liang2, WANG Zhu-Qing3   

  1. 1 School of Chemical & Environment Science, Shaanxi University of Technology, Hanzhong 723001, Shaanxi Province, P. R. China;
    2 Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, P. R. China;
    3 Shandong Provincial Key Laboratory of Ocean Environment Monitoring Technology, Shandong Academy of Sciences Institute of Oceanographic Instrumentation, Qingdao 266001, Shandong Province, P. R.China
  • Received:2014-01-20 Revised:2014-03-31 Published:2014-05-26
  • Contact: XU Qiong, WANG Wen-Liang;
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173139, 21207081), Education Department of Shaanxi Provincial Government Research Project, China (12JK0625), Funds of Research Programs of Shaanxi University of Technology, China (SLGQD13(2)-3, SLGQD13(2)-4), and Natural Science Foundation of Shandong Province, China (ZR2012DQ001).


The reaction mechanism and rate constant of the H2O2+Cl reaction, with and without a single water molecule, was investigated theoretically at the CCSD(T)/aug-cc-pVTZ//B3LYP/aug-cc-pVTZ level of theory. The calculated results show that there is only one channel for the formation of HO2+HCl in the naked H2O2+Cl reaction with an apparent activation energy of 10.21 kJ·mol-1. When one water molecule is added, the product of the reaction does not change, but the potential energy surface of the reaction becomes complex, yielding three different channels RW1, RW2, and RW3. The single water molecule in the RW1 and RW2 reaction channels has a negative influence on reducing the reaction barrier for the formation of HO2+HCl, whereas it has a positive influence in Channel RW3. Additionally, to estimate the importance of these processes in the atmosphere, their rate constants were evaluated using conventional transition state theory with the Wigner tunneling correction. The result shows that the rate constant for the naked H2O2+Cl reaction is 1.60×10-13 cm3 ·molecule-1 ·s-1 at 298.2 K, which is in good agreement with experimental values. Although the rate constant of channel RW3 is predicted to be 46.6-131 times larger than that of the naked H2O2+Cl reaction, its effective rate constant is smaller by 10-14 orders of magnitude than that of the naked reaction, that is, for the H2O2 + Cl reaction the naked reaction almost exclusively occurs under tropospheric conditions.

Key words: H2O2, Cl, Water-catalyzed, Reaction mechanism, Rate constant