A new synthetic procedure to make the condensed phase hydrogen storage material, ammonia borane (NH3BH3, abbreviated as AB), is described and compared with previous literature procedures. Ammonia borane with a gravimetric density ca. 194 gm H2/kg and a volumetric density ca. 146 H2/liter, is a promising chemical hydrogen storage material for fuel cell powered applications. The work shows that ammonium borohydride, NH4BH4, formed in situ by the metathesis of NH4X and MBH4 salts (M = Na, Li; X = Cl, F) in liquid NH3, can be induced to decompose in an organic ether to yield AB in near quantitative yield. The purity of the AB prepared by this one-pot synthetic strategy is sufficient to meet the thermal stability requirements for on-board hydrogen storage.
Revised: July 2, 2009 |
Published: July 5, 2008
Citation
Heldebrant D.J., A.J. Karkamkar, J.C. Linehan, and T. Autrey. 2008.Synthesis of Ammonia Borane for Hydrogen Storage Applications.Energy & Environmental Science 1, no. 1:156-160.PNNL-SA-61234.