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Magnesium and Magnesium-based alloys are considered to be promising storage media because of their hydrogen storge capacity (7.66wt.% for pure Mg), low density, low cost and high availability. However, commercial application of the magnesium hydride currently inhabited by its high absorption/desorption temperature, poor reaction kinetics, high oxidation reactivity. To overcome these disadvantages, mant researchers studied techniques such as catalysing, nanostructuring and alloying. Furthermore, milling used as a hydrogen storage material has positive effects on hydrogenation behavior because a high surface area can be obtained by milling. A few studies were conducted for MgHx intermixed with fluorides system. Yavari et al. and Ma et al. reported that MgF2 formed from the MgHx-transition metal fluorides system can be replaces the initial surface oxide later and provides a reactive and protective fluorinated surface for hydrogen uptake. Thus the absorption/deorption kinetics will be enhanced. In this research, the MgHx-CeF3 has been prepared by planetary ball milling under argon atmosphere. MgHx conatining 5 and 10 Vol.% of fluoride was charged with 17.7mm diamete Cr-steel ball into BPR 66:1. The synthesized powders were haracterized by XRD, SEM, EDS, BET and simultaneous TG/DSC analysis. The hydrogenation behaviors were measured by using Sievert's type automatic Pressure-Composition-Temperature (PCT) apparatus. The results of XRD patterns indicated that MgHx-CeF3 composites contain MgH2, CeH2, CeF3 and MgF2 respectively, after milling for 96hours. SEM observation revealed that MgHx-CeF3 composites has both small and large particle with fine particles on their surfaces. EDS image mapping of MgHx-CeF3 compotsites shown that, each element is distributed homogeneously. The specific surface area of MgHx was 1.547m2/g, that of MgHx-5, 10Vol.%CeF3 was 6.336, 4.969m2/g, respectively.

Hydrogen storage materials, Sorption kinetics, Metal hydride, MgHx-CeF3 composites, Mechanical grinding