LAUSR

Abstract Grand canonical Monte Carlo simulations were conducted at T = 77 and 298 K to predict adsorption isotherms for hydrogen in two aluminum-based Metal-Organic Frameworks (MOFs) with the same framework topology, MOF-519 and MOF-520. We explored the effects of pressure on hydrogen adsorption in both materials. In addition, the adsorption mechanism as well as the preferred adsorption sites in both materials were also studied. The GCMC results showed that MOF-519 exhibited an excellent storage capacity for H 2 at lower pressure, which can be attributed to its high adsorption heat. While at higher pressure, MOF-520 showed much better hydrogen adsorption performance due to its high specific surface area and pore volume. The results also indicated that the strongest adsorption sites for H 2 in MOF-519 were near the oxygen atoms of bicarboxylic linkers, while aluminum-oxygen clusters were preferential adsorption sites for hydrogen in MOF-520.