A method is disclosed for directly preparing an alkaline earth metal
borohydride, i.e. Ca(BH.sub.4).sub.2, from the alkaline earth metal
hydride and the alkaline earth metal boride. The borohydride thus
prepared is doped with a small portion of a metal chloride catalyst
compound, such as RuCl.sub.3, TiCl.sub.3, or a mixture of TiCl.sub.3 and
palladium metal. The process provides for mechanically mixing the dry
reagents under an inert atmosphere followed by charging the mixed
materials with high pressure hydrogen at about 70 MPa while heating the
mixture to about 400.degree. C. The method is relatively simple and
inexpensive and provides reversible hydride compounds which are free of
the usual contamination introduced by prior art wet chemical methods.