Hydrogen Absorption/Desorption in Nanostructured Fe- and Ti-Doped Mg₂Ni Alloys

Abstract

Nanostructured Mg2Ni, Fe-doped and Ti-doped Mg2Ni alloys for hydrogen storage applications have been produced by means of Mechanically Activated Self-propagating High temperature Synthesis (MASHS). Different molar compositions of Fe and Ti (0.1; 0.3 and 0.5) have been studied in order to determine their influence in the hydrogen sorption properties. Different Mg-Ni based alloys have been tested in order to study their hydrogen sorption behavior. The hydrogenation was carried out in a Pressflow Gas Controller. Subsequently, the dehydrogenation process was conducted by means of a Differential Scanning Calorimetry (DSC) equipped with an H2 detector of the purged gas. The MASHS method has been demonstrated to be effective for the obtainment of nanostructured pure and doped Mg2Ni intermetallics. In addition, the materials produced showed hydrogen storage capacities superior to 4wt%, especially in the case of Fe-doped Mg2Ni and a slight reduction of desorption temperature was reached with Ti-doped Mg2Ni. Finally, the activation energy of the dehydrogenation process was evaluated and Ti-doped sample exhibited the lower activation energy value. Obtained results are promising for technological applications of Mg-based alloys.