Liu Yang, Song Hongwei, Li Jun
School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.
State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.
Phys Chem Chem Phys. 2020 Oct 28;22(41):23657-23664. doi: 10.1039/d0cp04120c.
The reaction OH + HO2 → H2O + O2 is a prototype of radical-radical reactions. It plays an important role in interstellar/atmospheric chemistry and combustion, and considerable attention has thus been dedicated to its kinetics. In our previous work, we reported an accurate full-dimensional potential energy surface for the title reaction on the ground triplet electronic state. The quasi-classical trajectory (QCT) approach was employed to investigate its kinetics. Although the QCT rate coefficients were in good agreement with some experimental and theoretical results, QCT cannot account for the quantum mechanical effects, such as zero-point vibrational energy, recrossing, and tunneling, which may significantly affect the rate coefficients, particularly at low temperatures. In this work, the reduced-dimensional quantum dynamics and ring polymer molecular dynamics calculations were carried out to examine these effects and their impact on rate coefficients over the temperature range of 300-1300 K.
反应OH + HO₂ → H₂O + O₂是自由基-自由基反应的一个典型例子。它在星际/大气化学和燃烧过程中起着重要作用，因此其动力学受到了广泛关注。在我们之前的工作中，我们报道了基态三重态电子态下该反应精确的全维势能面。采用准经典轨迹（QCT）方法研究了其动力学。虽然QCT速率系数与一些实验和理论结果吻合良好，但QCT无法考虑量子力学效应，如零点振动能、再穿越和隧穿，这些效应可能会显著影响速率系数，尤其是在低温下。在这项工作中，进行了降维量子动力学和环聚合物分子动力学计算，以研究这些效应及其在300 - 1300 K温度范围内对速率系数的影响。
