Fullerene-impregnated IRMOFs for balanced gravimetric and volumetric H2 densities: A combined DFT and GCMC simulations study

This paper aimed to study the effects of fullerene (C-60) impregnation on the isoreticular metal-organic framework (IRMOF) materials MOF-650 (ZnO4 nodes were connected to azulenedicarboxylate linkers), MOF-5(ZnO4 nodes were connected to benzenedicarboxylate linkers), and IRMOF-10 (ZnO4 nodes were connected to biphenyldicarboxylate linkers) for H-2 storage, these IRMOFs had similar structures but different pore volumes and organic linkers. Density functional theory (DFT) and grand canonical monte Carlo (GCMC) calculations indicated that C-60 plays an important role in balancing the gravimetric and volumetric H-2 densities of the IRMOFs. The C-60@IRMOFs revealed improved volumetric density when H-2 was undersaturated but reduced gravimetric density under H-2 saturation. The saturated gravimetric H-2 density of the IRMOFs was decided by the free volume. At 77 K, C-60@MOF-650 had a gravimetric H-2 density of 5.3 wt% and volumetric H-2 density of 42 g/L under 10 bar, and C-60@IRMOF-10 had a gravimetric H-2 density of 7.4 wt% and volumetric H-2 density of 43 g/L under 18 bar. These values nearly meet the United States Department of Energy (DOE) gravimetric and volumetric H-2 density ultimate targets (gravimetric H-2 density, 6.5 wt%; volumetric H-2 density, 50 g/L) under ambient pressures. Among the studied IRMOFs, C60@MOF-650 and C60@IRMOF-10 demonstrated the best H-2 storage properties at 233 and 298 K. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This paper investigates the effects of fullerene (C-60) impregnation on various isoreticular metal-organic framework (IRMOF) materials for H-2 storage. It was found that C-60 played a key role in balancing the gravimetric and volumetric H-2 densities of the IRMOFs, with C-60@IRMOF-10 showing the best H-2 storage performance among the studied IRMOFs at different temperatures and pressures.