Abstract
We report formation of alanate composites by high energy ball milling method under inert atmosphere and the decomposition temperature and kinetic studies of the decomposition temperature. Alanate/niobium fluoride composite decreases the decomposition temperature comprehensively compared to chloride and oxide alanate composites implying the fluoride was the most favorable catalyst. Hydrogen desorption as well as kinetics increases with increasing temperature up to 200 degrees C of alanate/niobium fluoride composite. XRD analysis demonstrated that fluoride decomposes completely with sodium alanate during ball milling provides better homogeneous mixture for hydrogen desorption due to its low melting temperature. This work also shows the oxide during ball milling remain as such without mixing with the alanate due to high melting point and have least effect in reducing the decomposition temperature. All the composite samples were characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TGA) coupled with differential scanning calorimetry (DSC). The dehydrogenation behavior of alanate composite samples was performed by using Sievert's volumetric apparatus under vacuum conditions at different temparatures.