Abstract A realistic molecular-level description of catalytic reactions on single-crystal metal surfaces can be provided by stochastic multisite lattice-gas (msLG) models. This approach has general applicability, although in this report, we will focus on the example of CO-oxidation on the unreconstructed fcc metal (1 0 0) or M(1 0 0) surfaces of common catalyst metals M = Pd, Rh, Pt and Ir (i.e., avoiding regimes where Pt and Ir reconstruct). These models can capture the thermodynamics and kinetics of adsorbed layers for the individual reactants species, such as CO/M(1 0 0) and O/M(1 0 0), as well as the interaction and reaction between different reactant species in mixed adlayers, such as (CO + O)/M(1 0 0). The msLG models allow population of any of hollow, bridge, and top sites. This enables a more flexible and realistic description of adsorption and adlayer ordering, as well as of reaction configurations and configuration-dependent barriers. Adspecies adsorption and interaction energies, as well as barriers for various processes, constitute key model input. The choice of these energies is guided by experimental observations, as well as by extensive Density Functional Theory analysis. Model behavior is assessed via Kinetic Monte Carlo (KMC) simulation. We also address the simulation challenges and theoretical ramifications associated with very rapid diffusion and local equilibration of reactant adspecies such as CO. These msLG models are applied to describe adsorption, ordering, and temperature programmed desorption (TPD) for individual CO/M(1 0 0) and O/M(1 0 0) reactant adlayers. In addition, they are also applied to predict mixed (CO + O)/M(1 0 0) adlayer structure on the nanoscale, the complete bifurcation diagram for reactive steady-states under continuous flow conditions, temperature programmed reaction (TPR) spectra, and titration reactions for the CO-oxidation reaction. Extensive and reasonably successful comparison of model predictions is made with experimental data. Furthermore, we discuss the possible transition from traditional mean-field-type bistability and reaction kinetics for lower-pressure to multistability and enhanced fluctuation effects for moderate- or higher-pressure. Behavior in the latter regime reflects a stronger influence of adspecies interactions and also lower diffusivity in the higher-coverage mixed adlayer. We also analyze mesoscale spatiotemporal behavior including the propagation of reaction–diffusion fronts between bistable reactive and inactive states, and associated nucleation-mediated transitions between these states. This behavior is controlled by complex surface mass transport processes, specifically chemical diffusion in mixed reactant adlayers for which we provide a precise theoretical formulation. The msLG models together with an appropriate treatment of chemical diffusivity enable equation-free heterogeneous coupled lattice-gas (HCLG) simulations of spatiotemporal behavior. In addition, msLG + HCLG modeling can describe coverage variations across polycrystalline catalysts surfaces, pressure variations across catalyst surfaces in microreactors, and could be incorporated into a multiphysics framework to describe mass and heat transfer limitations for high-pressure catalysis.

中文翻译：

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催化表面反应的真实多点晶格气体建模和 KMC 模拟：金属 (100) 表面 CO 氧化的动力学和多尺度空间行为

摘要 随机多位点晶格气体 (msLG) 模型可以提供对单晶金属表面催化反应的真实分子级描述。这种方法具有普遍适用性，尽管在本报告中，我们将重点介绍常见催化剂金属 M = Pd、Rh、Pt 的未重构 fcc 金属 (1 0 0) 或 M(1 0 0) 表面上的 CO 氧化示例和 Ir（即避免 Pt 和 Ir 重构的机制）。这些模型可以捕获单个反应物物种的吸附层的热力学和动力学，例如 CO/M(1 0 0) 和 O/M(1 0 0)，以及混合中不同反应物物种之间的相互作用和反应。 adlayers，例如 (CO + O)/M(1 0 0)。msLG 模型允许填充任何空心、桥和顶部站点。这使得对吸附和吸附层排序以及反应构型和与构型相关的障碍的描述更加灵活和现实。 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adspecies 吸附和相互作用能，以及各种过程的障碍，构成了关键的模型输入。这些能量的选择受实验观察以及广泛的密度泛函理论分析的指导。模型行为通过动力学蒙特卡罗 (KMC) 模拟进行评估。我们还解决了与反应物种类（例如 CO）的非常快速扩散和局部平衡相关的模拟挑战和理论后果。这些 msLG 模型用于描述单个 CO/M(1 0 0) 和 O/M(1 0 0) 反应物吸附层。此外，它们还用于预测纳米级的混合 (CO + O)/M(1 0 0) 吸附层结构、连续流动条件下反应稳态的完整分叉图、程序升温反应 (TPR) 光谱和滴定反应用于 CO 氧化反应。模型预测与实验数据进行了广泛且合理成功的比较。此外，我们讨论了从低压的传统平均场型双稳态和反应动力学到中压或高压的多稳态和增强波动效应的可能转变。后一种情况下的行为反映了物种相互作用的更强影响，以及更高覆盖率混合adlayer 中的较低扩散率。我们还分析了中尺度时空行为，包括双稳态反应和非活动状态之间反应扩散前沿的传播，以及这些状态之间相关的成核介导的转变。这种行为受复杂的表面传质过程控制，特别是混合反应物吸附层中的化学扩散，我们为此提供了精确的理论公式。msLG 模型以及对化学扩散率的适当处理使时空行为的无方程异质耦合晶格气体 (HCLG) 模拟成为可能。此外，msLG + HCLG 建模可以描述多晶催化剂表面的覆盖变化、微反应器中催化剂表面的压力变化、