Novel metal graphene framework (MGF) structures for hydrogen storage

Hierarchical novel metal graphene framework (MGF) structures designed, constructed and used for hydrogen storage by adsorption. Three different amounts of pillars used for connecting carboxylate functionalized graphene layers. The three-dimensional atomistic models optimized and then the aqua molecules removed which are coordinated to metal between graphene layers as bridge. Hydrogen storage abilities of aqua free models also investigated. The aqua existence made the structures more effective to store hydrogen according to simulation results. The highest storage capacity calculated for 181C.Aq named structure that includes aqua molecules inside could store 7.745 wt percentage hydrogen at 77 K and 100 bars pressure conditions. Hydrogen storage capacity decreases almost to half by removing aqua molecules for same structure. It is clear the coordinated aqua existence around the bridging atoms provides the spaces between graphene layers. In other word, the spaces between the graphene layers collapse by aqua removal so the hydrogen storage capacities decrease dramatically. Finally, spacing between graphene layers by bridges makes them very effective for hydrogen storage.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Hierarchical novel metal graphene framework structures were designed and used for hydrogen storage, with the addition of aqua molecules found to enhance the storage efficiency, while removal of aqua molecules in the same structure led to a significant decrease in hydrogen storage capacity.