Zhang Tianlei, Lan Xinguang, Qiao Zhangyu, Wang Rui, Yu Xiaohu, Xu Qiong, Wang Zhiyin, Jin Linxia, Wang ZhuQing
Shaanxi Key Laboratory of Catalysis, School of Chemical & Environment Science, Shaanxi University of Technology, Hanzhong, Shaanxi 723001, P. R. China.
Analytical and Testing Center, Sichuan University of Science & Engineering, Zigong 643000, Sichuan Province, P. R. China.
Phys Chem Chem Phys. 2018 Mar 28;20(12):8152-8165. doi: 10.1039/c8cp00020d. Epub 2018 Mar 9.
To study the catalytic effects of (HO) (n = 1-3), the mechanisms of the reaction HO + HO →O + HO without and with (HO) (n = 1-3) have been investigated theoretically at the CCSD(T)/aug-cc-pVTZ//M06-2X/aug-cc-pVTZ level of theory, coupled with rate constant calculations using the conventional transition state theory. Our results show that upon incorporation of (HO) (n = 1-3) into the channel of HO + O formation, two different reactions, i.e. HO + HO(HO) (n = 1-3) and HO + HO(HO) (n = 1-3), have been observed, and these two reactions are competitive with each other. The catalytic effects of (HO) (n = 1-3) mainly arise from the contribution of a single water vapor molecule; this is because the effective rate constants with water are respectively larger by 2-3 and 3-4 orders of magnitude than those of the reactions with (HO) and (HO). Furthermore, the catalytic effects of the water monomer mainly arise from the HOHO + HO reaction, and the enhancement factor of this reaction is obvious within the temperature range of 240.0-425.0 K, with the branching ratio (k'(RW)/k) of 17.27-80.77%. Overall, the present results provide a new example of how water and water clusters catalyze gas phase reactions under atmospheric conditions.
为了研究(HO)（n = 1 - 3）的催化作用，在CCSD(T)/aug-cc-pVTZ//M06-2X/aug-cc-pVTZ理论水平下，结合使用传统过渡态理论的速率常数计算，从理论上研究了有无(HO)（n = 1 - 3）时反应HO + HO →O + HO的机理。我们的结果表明，当将(HO)（n = 1 - 3）引入HO + O形成通道时，观察到了两种不同的反应，即HO + HO(HO)（n = 1 - 3）和HO + HO(HO)（n = 1 - 3），并且这两种反应相互竞争。(HO)（n = 1 - 3）的催化作用主要源于单个水蒸气分子的贡献；这是因为与水反应的有效速率常数分别比与(HO)和(HO)反应的有效速率常数大2 - 3个数量级和3 - 4个数量级。此外，水单体的催化作用主要源于HOHO + HO反应，并且在240.0 - 425.0 K的温度范围内该反应的增强因子明显，分支比（k'(RW)/k）为17.27 - 80.77%。总体而言，目前的结果提供了一个新的例子，说明了水和水簇在大气条件下如何催化气相反应。
