Füchsel Gernot, Zhou Xueyao, Jiang Bin, Juaristi J Iñaki, Alducin Maite, Guo Hua, Kroes Geert-Jan
Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
Institut für Chemie und Biochemie-Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustraße3, 14195 Berlin, Germany.
J Phys Chem C Nanomater Interfaces. 2019 Jan 31;123(4):2287-2299. doi: 10.1021/acs.jpcc.8b10686. Epub 2019 Jan 4.
The HCl + Au(111) system has recently become a benchmark for highly activated dissociative chemisorption, which presumably is strongly affected by electron-hole pair excitation. Previous dynamics calculations, which were based on density functional theory at the generalized gradient approximation level (GGA-DFT) for the molecule-surface interaction, have all overestimated measured reaction probabilities by at least an order of magnitude. Here, we perform ab initio molecular dynamics (AIMD) and AIMD with electronic friction (AIMDEF) calculations employing a density functional that includes the attractive van der Waals interaction. Our calculations model the simultaneous and possibly synergistic effects of surface temperature, surface atom motion, electron-hole pair excitation, the molecular beam conditions of the experiments, and the van der Waals interaction on the reactivity. We find that reaction probabilities computed with AIMDEF and the SRP32-vdW functional still overestimate the measured reaction probabilities, by a factor 18 for the highest incidence energy at which measurements were performed (≈2.5 eV). Even granting that the experiment could have underestimated the sticking probability by about a factor three, this still translates into a considerable overestimation of the reactivity by the current theory. Likewise, scaled transition probabilities for vibrational excitation from ν = 1, = 1 to ν = 2 are overestimated by the AIMDEF theory, by factors 3-8 depending on the initial conditions modeled. Energy losses to the surface and translational energy losses are, however, in good agreement with experimental values.
HCl + Au(111)体系最近已成为高活化解离化学吸附的一个基准，据推测这种化学吸附会受到电子 - 空穴对激发的强烈影响。先前基于广义梯度近似水平（GGA - DFT）的分子 - 表面相互作用的动力学计算，都至少将测量得到的反应概率高估了一个数量级。在此，我们进行了从头算分子动力学（AIMD）以及包含有吸引力的范德华相互作用的密度泛函的带电子摩擦的从头算分子动力学（AIMDEF）计算。我们的计算模拟了表面温度、表面原子运动、电子 - 空穴对激发、实验的分子束条件以及范德华相互作用对反应性的同时且可能协同的影响。我们发现，用AIMDEF和SRP32 - vdW泛函计算得到的反应概率，对于进行测量的最高入射能量（≈2.5 eV），仍比测量得到的反应概率高估了18倍。即使假设实验可能将粘附概率低估了约三倍，这仍然意味着当前理论对反应性的高估程度相当大。同样，AIMDEF理论高估了从ν = 1、 = 1到ν = 2的振动激发的标度跃迁概率，高估倍数在3 - 8倍之间，具体取决于所模拟的初始条件。然而，向表面的能量损失和平动能量损失与实验值吻合良好。
