Thermodynamic and Kinetic Destabilization of Magnesium Hydride Using Mg-In Solid Solution Alloys

摘要

Efforts to thermodynamically destabilize magnesium hydride (MgH_2), so that it can be used for practical hydrogen storage applications, have been a difficult challenge that has eluded scientists for decades. This letter reports that MgH_2 can indeed be destabilized by forming solid solution alloys of magnesium with group Ⅲ and ⅣB elements, such as indium. Results of this research showed that the equilibrium hydrogen pressure of a Mg-0.1In alloy is 70% higher than that of pure MgH_2. The temperature at 1 bar hydrogen pressure (T_(1bar)) of Mg-0.1In alloy was reduced to 262.9 ℃ from 278.9 ℃, which is the T_(1bar) of pure MgH_2. Furthermore, the kinetic rates of dehydrogenation of Mg-0.1In alloy hydride doped with a titanium intermetallic (TiMn_2) catalyst were also significantly improved compared with those of MgH_2.