Development of Polymer-based Materials for Hydrogen Storage Applications: an overview

Nowadays, different kinds of renewable and natural energy sources such as solar, wind or geothermal energy could be the key to limiting the pollution problem. In the last years, the idea to use hydrogen a storable, clean and economical energy vector has been spread. Naturally, there are many difficulties in realising a hydrogen-based, technological and economic model: production, storage and transport. Producing hydrogen is hard, but storing, stocking and transport it is more challenging. Usually, hydrogen is stored in the gas compressed form or in liquid state. Research has dealt with new materials that adsorb and release hydrogen under specific temperature and pressure conditions, occupying a reduced volume. At CNR-ITAE, the hydrogen storage activity focuses on the study and development of different materials with promising hydrogen sorption capability. Some of these have natural origins; other are designed and synthesized in the laboratory: metal hydrides based on Mg, activated carbons coming from banana peels, coffee grounds, wood chips and algae wastes, polymeric coverage for metal alanates, composite polymers containing a metal oxide. This study summarises the most important activities and results obtained from activated carbons and Mg hydrides and will describe in greater detail the activities concerning the development of composite polymer Mn oxide-based and the polymer coverage of metal alanates. In the first case, many chemical-physical and H2 sorption/desorption studies were performed. In addition, theoretical DFT chemical modelling studies were carried out. Furthermore, a prototype tank was developed to utilise this kind of material, which supplied H2 to a fuel cell. 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 was studied.