Study and Development of Innovative Materials for Hydrogen Storage Activity

Hydrogen, the most abundant element in the universe, could solve problems related to environmental pollution impact. But it is difficult to store it at room temperature due to its low density. Usually, hydrogen is stored in the gas compressed form or in liquid state. During last years, research has dealt with new materials that adsorb and release hydrogen under certain temperature and pressure conditions, occupying a reduced volume. These conditions are very important, in particular, in the transport sector. At CNR-ITAE, the hydrogen storage activity is focused on different materials having promising hydrogen sorption capability. Some of these have natural origins, other ones are designed and synthetized in laboratory: Lava Etna powders, banana peels, polymeric coverage for metal alanates, composite polymers containing metal oxide. Two kinds of volcanic powders, coming from Etna eruptions (1880 and 2006), are studied and characterised. Their slight different compositions are probably responsible of their different hydrogen sorption degrees: after activation, powder of 2006 is more efficient than one of 1880. Inspired by storage literature on activated carbon obtained from vegetal matrix, a study on carbonized banana peels, focusing the attention on activation methods and porosity, fundamental points for this scope, was carried out. Hydrogen sorption properties of alanates are known, but their high reactivity with air exposition is a big limit. So, a method to cover alanates with a particular polymeric capsule (Polysulphone, Polyetilene, etc) with high selective permeability for hydrogen is studied. Previous results, demonstrated that Mn oxides are promising for H2 sorption systems. To improve their storage capabilities (3wt% at 40bar/50°C after 300 hrs), a study on the steps of synthesis is carried out. Particularly, the precipitant solvent, chlorosulphonic acid and PEEK molar ratio, Mn oxide precursor concentration, reaction time, catalysts utilisation (to improve H2 sorption kinetic reaction) were investigated.