Hydrogen sorption properties of MgH2/10 wt.% graphite

V. FUSTER; F.J. CASTRO; G. URRETAVIZCAYA

Moscú

Simposio; International Symposium "Metal-Hydrogen Systems. Fundamentals and Applications"; 2010

Chemistry Department, Lomonosov Moscow State University

Hydrogen storage in magnesium based systems is largely studied due to the high hydrogen capacity and low cost of this metal. Nevertheless, the drawbacks related to the slow sorption kinetics and high thermodynamic stability of the hydride still give rise to many efforts in order to overcome these issues. Among others, one possibility to improve the hydrogen sorption properties of Mg is the addition of graphite. In this paper, MgH2/10 wt.% graphite prepared by reactive mechanical alloying under H2 atmosphere [1] is studied. The evolution of the desorption behaviour of samples extracted at different milling times, i.e. with different hydrogen content, is analyzed by DSC. The microstructure is studied by optical and electronic microscopy. The sorption properties for different amounts of hydride in the sample are studied by high pressure calorimetry (HPDSC) and conventional isothermal volumetric measurements. The relationship between the hydrogen desorption rate and the hydrogen content in the sample is associated with the reaction mechanism. References 1. V. Fuster, G. Urretavizcaya, F.J. Castro, J. Alloys Compd. 481 (2009) 673-680.