Gerrits Nick, Bogaerts Annemie
Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University P.O. Box 9502 2300 RA Leiden The Netherlands
Research Group PLASMANT, Department of Chemistry, University of Antwerp Universiteitsplein 1 BE-2610 Wilrijk Antwerp Belgium.
EES Catal. 2025 Apr 22. doi: 10.1039/d5ey00062a.
Vibrational excitation of reactants plays an important role in heterogeneous and plasma catalysis by increasing the reactivity of various rate-controlling steps. Therefore, state-of-the-art microkinetic models attempt to include this effect by modelling the change in reaction rate with the Fridman-Macheret approach. Although this approach is ubiquitous in simulations of plasma catalysis, it is not well established how accurate it is. In this work, we evaluate the Fridman-Macheret approach by comparing it to vibrational efficacies obtained with molecular dynamics simulations. Unfortunately, the agreement is extremely poor ( = -0.35), raising questions about the suitability of using this method in describing vibrationally excited dissociative chemisorption on metal surfaces, as is currently the norm in plasma catalysis. Furthermore, the approach lacks vibrational mode specificity. Instead, we propose an alternative model at comparable computational cost, which is fitted to theoretical vibrational efficacies obtained with molecular dynamics. Our model uses (1) the barrier height to dissociative chemisorption, (2) an indication of how "late" the barrier is, and (3) the overlap of vibrational modes and the reaction coordinate at the barrier. These three features lead to a considerable qualitative and quantitative ( = 0.52) improvement over the Fridman-Macheret approach. Therefore, we advise to make use of our new model, since it can be readily plugged into existing microkinetic models for heterogeneous and plasma catalysis.
反应物的振动激发通过提高各种速率控制步骤的反应活性，在多相催化和等离子体催化中起着重要作用。因此，目前最先进的微观动力学模型试图通过用弗里德曼 - 马切雷特方法对反应速率的变化进行建模来纳入这种效应。尽管这种方法在等离子体催化模拟中普遍存在，但其准确性如何尚未得到充分证实。在这项工作中，我们通过将弗里德曼 - 马切雷特方法与分子动力学模拟获得的振动效率进行比较来评估该方法。不幸的是，两者的一致性非常差（= -0.35），这引发了关于在描述金属表面上振动激发的解离化学吸附时使用这种方法是否合适的疑问，而这正是目前等离子体催化中的常规做法。此外，该方法缺乏振动模式特异性。相反，我们提出了一种计算成本相当的替代模型，该模型与分子动力学获得的理论振动效率相拟合。我们的模型使用（1）解离化学吸附的势垒高度，（2）势垒“延迟”程度的指示，以及（3）振动模式与势垒处反应坐标的重叠。这三个特征使得该模型在定性和定量方面（= 0.52）比弗里德曼 - 马切雷特方法有了相当大的改进。因此，我们建议使用我们的新模型，因为它可以很容易地插入到现有的用于多相催化和等离子体催化的微观动力学模型中。
