Metal-Organic Frameworks Impregnated with Magnesium-Decorated Fullerenes for Methane and Hydrogen Storage

A new concept is described for methane and hydrogen storage materials involving the incorporation of magnesium-decorated fullerenes within metal-organic frameworks (MOFs). The system is modeled using a novel approach underpinned by surface. potential energies developed from Lennard-Jones parameters. Impregnation of MOF pores with magnesium-decorated Mg10C60 fullerenes, denoted as Mg-C-60@MOF, places exposed metal sites with high heats of gas adsorption into intimate contact with large surface area MOF structures. Perhaps surprisingly, given the void space occupied by C-60, this impregnation delivers remarkable gas uptake, according to our modeling, which predicts exceptional performance for the Mg-C-60@MOF family of materials. These predictions include a volumetric methane uptake of 265 v/v, the highest reported value for any material, which significantly exceeds the U.S. Department of Energy target of 180 v/v. We also predict a very high hydrogen adsorption enthalpy of 11 kJ mol(-1) with relatively little decrease as a function of H-2 filling. This value is close to the calculated optimum value of 15.1 kJ mol(-1) and is achieved concurrently with saturation hydrogen uptake in large amounts at pressures under 10 atm.