ADVANCED NANOSTRUCTURED MATERIALS AS MEDIA FOR  HYDROGEN STORAGE

E. David, V. Niculescu, C. Sandru, M. Constantinescu

National Institute of Cryogenics & Isotopic Technologies, Rm.Valcea, P.O.Box 10, Code 240050, Romania

In a future sustainable energy system based on renewable energy, environmentally harmless energy carriers like hydrogen, will be of crucial importance [1, 2]. One of the major impediments for the transition to a hydrogen based energy system is the lack of satisfactory hydrogen storage alternatives. Hydrogen storage in nanostructured materials has been proposed as a solution for adequate hydrogen storage for a number of applications, in particular for transportation [3].
This paper is a preliminary study with the focus on possibilities for hydrogen storage in zeolites, alumina and nanostructured carbon materials [4-8]. The adsorption properties of these materials were evaluated in correlation with their internal structure. From N2 physisorption data the BET surface area (SBET), total pore volume (PV), micropore volume (MPV) and total surface area (St) were derived. H2 physisorption measurements were  performed at 77 K and to a pressure of 1 bar. From these data were determined the adsorption capacities of sorbent materials. It is concludent that microporous adsorbents, e.g activated carbons, display appreciable sorption capacities. Based on their micropore volume, carbon-based sorbents have the largest adsorption capacity for H2, over 200 cm3 (STP)/g, at the prevailing conditions. By increasing the micropore volume (~ 1 cm3/g) of sorbents and optimization of the adsorption conditions it is expected to lead to adsorption capacity of ~ 560 cm3 (STP)/g, close to targets set for mobile applications. 

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