Postsynthetic Metalation of a New Metal–Organic Framework To Improve Methane Working Storage Capacity

In the design of metal–organic frameworks (MOFs) for methane storage, a balance must be struck between the porosity of the MOF, the internal pore environment, the adsorption thermodynamics, and the density. Herein, we report the design of a new Zr-MOF, termed MOF-700, which was metalated with various Cu­(II) salts to produce an isoreticular series of three new, highly porous MOFs (MOF-701, MOF-702, and MOF-703). The position of the metalated sites was determined by X-ray absorption spectroscopy, and the metalated frameworks were found to display high volumetric methane storage working capacities [206 cm3(STP) cm–3 at 298 K and 5.0–80.0 bar for MOF-701]. This constitutes an improvement of 50% over the performance of the parent MOF-700 [137 cm3(STP) cm–3] and highlights the prospect of optimization of methane working storage capacity by postsynthetic metalation.