Efficient parameterization of adsorbate–adsorbate interactions on metal surfaces

Quantitative modeling of surface reactions relies on accurate potential energy surfaces that include adsorbate–adsorbate interactions. Using density functional theory calculations we introduce an efficient procedure to parameterize adsorbate–adsorbate interactions and present results for interactions between O₂, O, OH and H₂O on Pt, Ir, Rh and Pd surfaces. The targeted interactions are important when describing, for example, the electrochemical oxygen reduction reaction. However, an accurate representation of both non-directional interactions and directional hydrogen bonds remains challenging. By analyzing the dominant contributions, we find that accurate parameterizations can be constructed by separately considering surface mediated electronic interactions and pairwise hydrogen bonds. Two methods are evaluated to account for interactions beyond nearest-neighbors. Our work provides a general framework to analyze adsorbate–adsorbate interactions and present parameterizations suitable for efficient kinetic Monte Carlo simulations.