Aluminum Hydride Polymorphs: Preparation, Characterization and Thermal Properties

摘要

Two aluminum hydride polymorphs (α-AlH3 and β-AlH_3) were prepared by desolvation of AlH3-etherate based on the organometallic synthesis method and the thermal properties of them were investigated using TG-DSC and ex situ XRD under heating and isothermal processes. The results suggest that the a polymorph is more stable than the β polymorph, and the decomposition of the less stable polymorph, β-AlH_3, occurs by an exothermic transformation to the a phase followed by the decomposition of α-AlH3 into Al and H_2, with partial direct decomposition occurring in the process of phase transition at low temperatures (<100 °C).