Hoffmann Max J, Bligaard Thomas
Department of Chemical Engineering , Stanford University , Stanford , California 94305 , United States.
SUNCAT Center for Interface Science and Catalysis, SLAC , National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States.
J Chem Theory Comput. 2018 Mar 13;14(3):1583-1593. doi: 10.1021/acs.jctc.7b00683. Epub 2018 Feb 7.
Mean-field microkinetic models in combination with Brønsted-Evans-Polanyi like scaling relations have proven highly successful in identifying catalyst materials with good or promising reactivity and selectivity. Analysis of the microkinetic model by means of lattice kinetic Monte Carlo promises a faithful description of a range of atomistic features involving short-range ordering of species in the vicinity of an active site. In this paper, we use the "fruit fly" example reaction of CO oxidation on fcc(111) transition and coinage metals to motivate and develop a lattice kinetic Monte Carlo solver suitable for the numerically challenging case of vastly disparate rate constants. As a result, we show that for the case of infinitely fast diffusion and absence of adsorbate-adsorbate interaction it is, in fact, possible to match the prediction of the mean-field-theory method and the lattice kinetic Monte Carlo method. As a corollary, we conclude that lattice kinetic Monte Carlo simulations of surface chemical reactions are most likely to provide additional insight over mean-field simulations if diffusion limitations or adsorbate-adsorbate interactions have a significant influence on the mixing of the adsorbates.
平均场微动力学模型与类似布朗斯特-埃文斯-波拉尼的标度关系相结合，已被证明在识别具有良好或有前景的反应性和选择性的催化剂材料方面非常成功。通过晶格动力学蒙特卡罗方法对微动力学模型进行分析，有望如实地描述一系列原子特征，包括活性位点附近物种的短程有序。在本文中，我们以fcc(111)过渡金属和硬币金属上的CO氧化“果蝇”示例反应为契机，开发了一种适用于速率常数差异极大这一数值挑战情况的晶格动力学蒙特卡罗求解器。结果表明，对于无限快速扩散且不存在吸附质-吸附质相互作用的情况，实际上有可能使平均场理论方法和晶格动力学蒙特卡罗方法的预测相匹配。作为一个推论，我们得出结论，如果扩散限制或吸附质-吸附质相互作用对吸附质的混合有显著影响，那么表面化学反应的晶格动力学蒙特卡罗模拟很可能比平均场模拟提供更多的见解。
