Progress in polymeric material for hydrogen storage application in middle conditions R. Pedicini a, * , B. Schiavo c , P. Rispoli b, c , A. Saccà a , A. Carbone a , I. Gatto a , E. Passalacqua a a CNR-ITAE, Institute for Advanced Energy Technologies “N. Giordano”, Via Salita S. Lucia sopra Contesse, 5, 98126 Messina, Italy b ITA, Institute for Advanced Technologies, SS113, n.174, C. da Milo, 91100 Trapani, Italy c Affiliated University of PalermoeDICGIM, Viale delle Scienze, Bdg, 90128 Palermo, Italy article info Article history: Received 14 May 2013 Received in revised form 11 October 2013 Accepted 25 November 2013 Available online xxx Keywords: Manganese oxide synthesis Chemicalephysical characterisation Hydrogen storage measurements abstract Hydrogen sorption using a manganese oxide anchored to PEEK (Poly(ether-ether-keton)) matrix was studied. The functionalization process and the obtained results on hydrogen storage capability of the synthesized polymer are reported. The functionalised polymer was characterised by Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray diffraction and Volumetric Hydrogen sorption measurements. Different synthesis conditions in terms of precursor concentration and reaction time were used and the direct correlation between manganese oxide percentage and hydrogen storage capability was confirmed. In this way different powders were synthesised. It is assumed that the sample with 78 wt% (SPMnO6) forms a combination of mixed manganese oxides since different reticular planes were observed. On this sample, promising results regarding to hydrogen capability at 110  C and 60 bar were obtained, in particular 1.1 wt% hydrogen sorption was recorded. Moreover, this value, after about 30 h, remains quite constant. These preliminary results demonstrate the capability of such compound to absorb hydrogen, for this reason further morphological and structural studies are in progress with the aim to better understand the mechanism involving the storage. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction The advantage of using hydrogen fed fuels cells instead of the other competitive technologies which use diesel or petrol or other hydrocarbons as fuel, stays in the possibility to reduce emission theoretically up to zero. Compared to internal combustion engines, also those one fed with hydrogen, fuel cells have higher efficiency, and, if a low temperature type is used, such as PEFC (Polymer Electrolyte Fuel Cells) or AFC (Alkaline Fuel Cells), NO x emission can be avoided as well. In addition, hydrogen should be produced from carbon-free sources, i.e. mainly water, through water splitting processes (electrolysis or other photo-mediated processes) driven by clean energy from renewable sources (wind, sun, tides, micro- organism, etc...). For these reason, hydrogen is considered one of the best alternative to conventional fuels but its storage currently implies the use of high pressure vessel with a consequent high risk for transportation. To solve this problem hydrogen storage on solid state materials is considered a more safe and effective way for different applications. In particular, the development of safe, compact, and high capacity storage systems is decisive for the use of fuel cells as power generator in portable and automotive applications. The current target set by the U.S. Department of Energy for 2017 requires the development of systems able to store 5.5 wt% of hydrogen [1]. Several materials including metal hydrides [2e4], complex metal hydrides [5], metal organic frameworks [6e8], carbon nanotubes [9e12], graphite and activated carbon [13,14] and metal/carbon nanostructures [15] exhibit promising charac- teristics as potential materials for hydrogen storage. Metal hydrides are actually considered the best class of mate- rials for hydrogen storage but their high intrinsic weight, due to presence of heavy metals, limits their use for a real application. Moreover, the hydrogen desorption involves energy-inefficient endothermic processes due to the use of high temperatures and/ or pressures that further limits the practical use [16]. For example, the hydrogen sorption content of MgH 2 is 7.6 wt% [17], but in the desorption reaction (2.4 wt%) the stored hydrogen is involved in the endothermic process, leaving only 5.2 wt% available for use. This problem is reduced but still significant with complex hydrides. Titanium-catalyzed alanates, which stores 5.5 wt% H 2 [18,19], re- quires 0.9 wt% H 2 for the dehydrogenation enthalpy, leaving only 4.6 wt% available. In both cases, the used energy exclusively * Corresponding author. Tel.: þ39 090 624 277; fax: þ39 090 624 247. E-mail address: rolando.pedicini@itae.cnr.it (R. Pedicini). Contents lists available at ScienceDirect Energy journal homepage: www.elsevier.com/locate/energy 0360-5442/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.energy.2013.11.073 Energy 64 (2014) 607e614