Studies on synthesis and dehydrogenation behavior of magnesium alanate and magnesium–sodium alanate mixture

Magnesium alanate (Mg(AlH4)2)(Mg(AlH4)2) has been synthesized by mechanochemically activated metathesis reaction involving MgCl2MgCl2 and NaAlH4NaAlH4. Its dehydrogenation kinetics and storage capacity has been studied by using Sievert's type apparatus. We have obtained dehydrogenation capacity of 2.7 wt% H2H2 from Mg(AlH4)2+2NaClMg(AlH4)2+2NaCl during the first decomposition step at 140∘C and 1.1 wt% H2H2 during second step decomposition at 280∘C. Efforts were carried out to reduce NaCl content from the product using Soxhlet extraction technique. The Soxhlet extracted product gives the total dehydrogenation capacity of 4.7 wt% H2H2. To enhance the storage capacity, we have synthesized a complex hydride consisting of mixture: xMg(AlH4)2+yNaAlH4xMg(AlH4)2+yNaAlH4(0