Second Generation MOF's for Hydrogen Storage

Matzger, Adam

University of Michigan. Regents.

关键词: Saturation;    Capacity;    08 Hydrogen;    Implementation;    Symmetry;   

DOI  :  10.2172/936781
RP-ID  :  None
RP-ID  :  FC26-05NT42447
RP-ID  :  936781

美国|英语

来源: UNT Digital Library

【 摘 要 】

This final technical report summarizes work exploring strategies to generate second generation metal organic frameworks (MOFs). These strategies were (a) the formation of interpenetrated frameworks and (b) the generation of coordinatively unsaturated metal centers (open metal sites). In the first phase of the project the effectiveness of these strategies was evaluated experimentally by measuring the saturation hydrogen uptake at high pressure and low temperature of 14 MOFs. The results of these studies demonstrated that surface area is the most useful parameter that correlates with ultimate hydrogen capacity. The strategy of interpenetration has so far failed to produce MOFs with high surface areas and therefore high saturation capacities for hydrogen have not been achieved. The incorporation of coordinatively unsaturated metal centers, however, is a promising strategy that allows higher heats of H2 adsorption to be realized without compromising surface area. Based on these initial findings, research efforts in phase two have concentrated on the discovery of new ultrahigh surface area materials with metal centers capable of supporting coordinative unsaturation without structural collapse. One approach has been the synthesis of new organic linkers that have more exposed edges, which is a factor that contributes to increasing surface area, at least when considering subunits of graphene sheets. Another strategy has been to synthesize MOFs with reduced symmetry linkers in order to generate structure types that are less likely to interpenetrate. Successful implementation of these strategies has resulted in the synthesis of 7 new compounds one of which is the highest surface area Cu based MOF reported to date.