Mechanochemical synthesis and thermal decomposition of Mg(AlH4)2

Abstract Magnesium alanate Mg(AlH 4 ) 2 has been synthesized by mechanochemically activated metathesis reaction between NaAlH 4 and MgCl 2 without solvent, this metathesis reaction proceeded completely. The thermal decomposition behavior of solvent-free Mg(AlH 4 ) 2 has been analyzed by TG/MS and DSC. It has been confirmed that Mg(AlH 4 ) 2 decomposes in two steps: the first decomposition reaction Mg(AlH 4 ) 2  → MgH 2  + 2Al + 3H 2 is exothermic and starts at about 115 °C. The second one Mg H 2 + 2 Al → 1 2 A l 3 M g 2 + 1 2 Al + H 2 is endothermic in total and starts at about 240 °C, although the formation reaction of Al 3 Mg 2 (3Al + 2Mg → Al 3 Mg 2 ) is exothermic.