Molecular Simulation Insights into Acid Gas Interactions within Ni‐Based Fluorinated Square‐Pillared Metal‐Organic Framework

The increasing prominence of metal-organic frameworks (MOFs) in gas separation technologies has sparked significant interest in their application in flue gas treatment. Nevertheless, the adsorption of acidic gases in MOFs presents significant challenges owing to their complex interactions with the framework. The adsorption interactions of acidic gases and their mixtures with [Ni(1,4-pyrazine)₂(AlF₅)]_n (ALFFIVE-Ni-Pyr) are explored while considering the flexibility of the framework. Using grand canonical Monte Carlo simulations, guest-host interactions are evaluated, focusing on gas loading, whereas molecular dynamics simulations highlight the structural dynamics induced by guest molecules within the framework. Density functional theory calculations further confirm the interactions between acidic gases and the framework. A significantly higher adsorption capacity for SO₂ than for CO₂ and NO₂ is shown in results, particularly in gas mixtures, highlighting the adaptability of the framework and its superior performance for acidic gas separation. This study aims to contribute to advancements in gas separation processes and provide valuable insights into the optimization of MOFs for industrial applications.