Atomistic Adsorption of Oxygen and Hydrogen on Platinum Catalysts by Hybrid Grand Canonical Monte Carlo/Reactive Molecular Dynamics

Abstract

The reactivity of a metal catalyst depends strongly on the adsorbate coverage, making it essential for the reactivity models to account for the in situ structures and properties of the catalyst under reaction conditions. The use of first principle based thermodynamic approaches to describe adsorbate–adsorbate interaction though attractive for its technical rigor is tedious and computationally demanding especially for metal nanoparticles. With the advent of empirical reactive force fields (ReaxFF), there is a great deal of interest to advance simulation approaches like hybrid grand canonical Monte Carlo reactive molecular dynamics (GCMC/RMD) that enable efficient use of ReaxFF to model the adsorptive states. The predictive ability of GCMC/RMD relies upon the quality of the force field, which in turn depends upon the training set used for its parametrization. To this end, we investigate the adsorption behavior of O and H over the Pt catalysts using the newly developed Pt/O/H ReaxFF. We assess the thermodyna...