Reaction between magnesium ammine complex compound and lithium hydride

The possibility of using ammonia as a hydrogen carrier is examined for the reaction between magnesium ammine complex MgCl2(NH3)6 and lithium hydride LiH. Sample was milled at low temperature of −40 °C to avoid decomposition of MgCl2(NH3)6 during the milling. The effects of milling time, milling speed (revolutions per minute), and catalysts on hydrogen storage properties were investigated by thermogravimetry, thermal desorption mass spectroscopy, and X-ray diffraction experiments. Experimental results indicated that a milled composite of Mg(NH3)6Cl2 and catalyzed-LiH desorbed the ∼100% H2 gas even at 125 °C in a closed system. The reverse reaction also proceeded by separately cooling MgCl2 at lower temperature than 100 °C and heating LiNH2 at 300 °C in the closed system.