Synthesis and hydrogen adsorption properties of a new iron based porous metal-organic framework

摘要

A new metal-organic framework [Fe_3O(OOC-C_6H_4-COO)_3(H_2O)_3]Cl·(H_2O)_x was synthesized with a speciu0001c surface area of 2823 m~2/g and a lattice parameter of 88.61 A. Isostructural with MIL-101, this compound exhibits similar hydrogen adsorption properties, with maximum adsorption capacity of 5.1wt.% H at 77 K. The adsorption enthalpy of hydrogen for MIL-101 and ITIM-1 (MIL-101Fe) at zero coverage was calculated for a wide temperature range of 77 K ÷324 K, considering corrections for the variation of hydrogen gas entropy with the temperature. The resulted adsorption enthalpy is 9.4 kJ/mol for MIL-101, in excellent agreement with the value reported in literature from microcalorimetric measurements, and a value of 10.4 kj/mol at zero coverage was obtained for ITIM-1 (MIL-101Fe).