Computational Study of Metal-Organic Frameworks for Hydrogen Sulfide Adsorption: Grand Canonical Monte Carlo and Molecular Dynamics Simulations

Hydrogen sulfide (H2S) is a highly toxic, and flammable acid gas that is widely present in confined spaces. However, conventional adsorption materials are inefficient and have poor reuse properties. Metal-organic frameworks (MOFs) show potential viability as novel materials in gas adsorption. Herein, mainstream MOFs were investigated based on molecular simulation techniques to explore the differences contributing to H2S adsorption. The adsorption process of H2S in MOFs was simulated by Grand Canonical Monte Carlo (GCMC) method, and the diffusion behavior was investigated based on molecular dynamics (MD) simulations. The results showed that the interaction energy and isosteric heat of adsorption were important criteria for determining the adsorption performance of H2S. The regulation of open metal sites could help to further enhance the adsorption of H2S, and the pore structure of MOFs affected the capture of H2S. A higher self-diffusion rate implies faster H2S capture. Hydrogen bonds affect the trapping efficiency of MOFs for H2S and the relative positions of ligands in the benzene ring cause subtle differences in adsorption. This study provides design strategies for the improvement of new high-performing MOFs for H2S adsorption in confined spaces.