| Abstract: | A method is disclosed for directly preparing an alkaline earth metal
borohydride, i.e. Mg(BH.sub.4).sub.2, from the alkaline earth metal
boride MgB.sub.2 by hydrogenating the MgB.sub.2 at an elevated
temperature and pressure. The boride may also be doped with small amounts
of a metal chloride catalyst such as TiCl.sub.3 and/or NiCl.sub.2. The
process provides for charging MgB.sub.2 with high pressure hydrogen above
at least 70 MPa while simultaneously heating the material to about
350.degree. C. to about 400.degree. C. The method is relatively simple
and inexpensive and provides a reversible hydride compound having a
hydrogen capacity of at least 11 wt %. |