3. Different synthesis methods

Among the various alanates, sodium alanate, NaAlH ₄ , is the most studied for reversible hydrogen storage due to its good thermodynamic properties and rapid reaction kinetics in the presence of doping agents. It can be produced by solution chemistry, by direct synthesis at high pressure and temperature, or by high-energy mechanical grinding (mechano-synthesis) either in an inert atmosphere or in a hydrogen atmosphere. Details of these methods are given below.

NaAlH ₄ can be prepared by reacting an alkali hydride and an aluminum halide at room temperature