Bottom-Up Approach to the Coarse-Grained Surface Model: Effective Solid–Fluid Potentials for Adsorption on Heterogeneous Surfaces

Coarse-grained surface models with a low-dimension positional dependence have great advantages in simplifying the theoretical adsorption model and speeding up molecular simulations. In this work, we present a bottom-up strategy, developing a new two-dimensional (2D) coarse-grained surface model from the “bottom-level” atomistic model, for adsorption on highly heterogeneous surfaces with various types of defects. The corresponding effective solid–fluid potential consists of a 2D hard wall potential representing the structure of the surface and a one-dimensional (1D) effective area-weighted free-energy-averaged (AW-FEA) potential representing the energetic strength of the substrate–adsorbate interaction. Within the conventional free-energy-averaged (FEA) framework, an accessible-area-related parameter is introduced into the equation of the 1D effective solid–fluid potential, which allows us not only to obtain the energy information from the fully atomistic system but also to get the structural dependence of...