Observation of Cu2+-H2 Interactions in a Fully Desolvated Sodalite-Type Metal-Organic Framework

摘要

The investigation of metal-organic frameworks has become one of the most active areas of chemical research, owing in part to their potential utility for hydrogen storage.[1] Unlike main-group and transition-metal hydrides, which chemically bind H2 and usually release it only at high temperatures, metal-organic frameworks and other high-surface-area adsorbents establish weak van der Waals interactions with H2 molecules, such that uptake and release can be achieved by a simple pressure swing. Typically, H2 adsorption enthalpies of only 5-7 kJ mol-1 characterize these weak interactions,[2] necessitating the use of cryogenic temperatures to achieve significant H2 uptake. It has been proposed, however, that adsorption enthalpies of approximately 15 kJ mol-1 would be optimal for H2 storage at 25 ℃ and at fuel-cell operating pressures of 1.5-100 bar.[3] To address the challenge of producing adsorbents with an enhanced H2 affinity, we have undertaken efforts to generate microporous metal-organic frameworks bearing a high concentration of coordinatively unsaturated metal centers.