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 %.
STATEMENT OF GOVERNMENT INTEREST
The United States Government has rights in this invention pursuant to Contract No. DE-AC04-94AL85000 between the United States Department of Energy and Sandia Corporation, for the operation of the Sandia National Laboratories.
PARTIES TO A JOINT RESEARCH AGREEMENT
The invention claimed herein was made as a result of activities undertaken within the scope of a joint research agreement initiated by the U.S. Department of Energy to establish a Metal Hydride Center of Excellence by and between Sandia National Laboratories and several other partners on Oct. 1, 2004 including Brookhaven National Laboratory (BNL); California Institute of Technology; Carnegie Mellon University; General Electric--Global Research: HRL, LLC; Internatix Corporation; the Jet Propulsion Laboratory (JPL); the National Institute of Standards and Technology (NIST); Oak Ridge National Laboratory (ORNL); Savannah River National Laboratory (SRNL); Stanford University; the University of Hawaii; the University of Illinois at Urbana-Champaign; the University of Nevada, Reno; the University of Pittsburgh; and the University of Utah.