Integrating Molecular Simulations and Experiments to Explore Hydrogen Adsorption and Storage in Fluorous Metal–Organic Frameworks

Hydrogen (H 2 ) stands out as the most promising clean, renewable energy source with a net zero carbon emission. Cryogenic H 2 storage for on-board vehicle applications using metal–organic frameworks (MOFs) has become a practical option with a good balance of safety, affordability, and efficiency. Before conducting extensive trials for vehicular fuel applications, it is crucial to understand the H 2 adsorption mechanism in MOFs using molecular simulations. In this work, we provide an integrated simulation and experimental investigation of H 2 uptake and storage in a series of fluorous MOFs, including the reference point structure FMOF-1a, three expansion models thereof previously obtained experimentally (FMOF-1b, FMOF-1c, and FMOF-2), and a uniform small-pore structure (FMOF-4)─all for the same 3,5-bis(trifluoromethyl)-1,2,4-triazolatosilver(I) complex empirical formula. Grand Canonical Monte Carlo simulations were employed to predict the adsorption isotherms at 77, 160, and 298 K, up to a pressure of 100 bar. Among different H 2 adsorption models simulated, the Darkrim and Levesque model agrees best with experimental adsorption data. While FMOF-1b is predicted to exhibit a greater affinity for H 2, as revealed by its higher Henry’s constant ( K H ) and isosteric heats of adsorption at infinite dilution ( Q st0 ), the highest H 2 uptake is projected for FMOF-2. Radial distribution function and density distribution analyses suggest that H 2 molecules adsorb preferentially in the small cavity region in FMOF-1b, FMOF-2, and FMOF-4. On the other hand, in FMOF-1a and FMOF-1c, the large channels are the preferred binding sites for H 2 . FMOF-2 exhibits the highest volumetric deliverable capacity (35.27 g L –1 ) under temperature- and pressure-swing conditions, highlighting its potential for practical cryogenic H 2 storage in on-board vehicle applications.