(265c) Performance Appraisal of Coverage-Explicit Mean-Field Microkinetic Modelling Strategies

Mean-field microkinetic models (MF-MKM) are important tools to rationalize the dynamics of a catalytic reaction on a surface. Parameterizations against density functional theory calculations often neglect the influence of lateral interactions between adsorbed intermediates on adsorption energies and reaction rates. However, it is well known that lateral interactions can affect predicted kinetic characteristics of a catalytic reaction. While explicit models based on the lattice-based kinetic Monte Carlo (kMC) approach can address this gap, they are computationally expensive and cannot be generalized to multiple reaction systems. In this work, we explore the consequences of common parameterization strategies employed to incorporate coverage effects in MF-MKM approaches. We define a simple two step reaction network on a hexagonal lattice with distance-dependent adsorbate-adsorbate interactions and neighbor-dependent reaction rates consistent with those commonly found on metal surfaces. We solve the model explicitly using kMC to provide ground-truth kinetic results. We then compare the kinetics of the same network using common approaches to parameterizing a coverage-explicit MF-MKM model. We highlight the performance of these schemes relative to predictions from the explicit model. Through these comparisons, we subsequently refine the parameterization procedure and establish a robust paradigm that yields results more faithful and consistent with the lattice kMC approach.