DOE and FreedomCAR technical targets of 6.0 and 9.0 wt.% are set forth capacities to realize a “holy grail” for hydrogen storage systems for 2010 and 2015 respectively. Alkali metal complex hydrides with high theoretical hydrogen capacity, for example: LiBH4 (18 wt.%), are being investigated for their properties to store large quantities of hydrogen. The catalytic doping of SiO2, seems to enhan...

We have developed a reactive force field (ReaxFF(MgH)) for magnesium and magnesium hydride systems. The parameters for this force field were derived from fitting to quantum chemical (QM) data on magnesium clusters and on the equations of states for condensed phases of magnesium metal and magnesium hydride crystal. The force field reproduces the QM-derived cell parameters, density, and the equat...

Pristine complex quaternary hydride (LiBH4/2LiNH2) and its destabilized counterpart (LiBH4/2LiNH2/nanoMgH2) have recently shown promising reversible hydrogen storage capacity under moderate operating conditions. The destabilization of complex hydride via nanocrystalline MgH2 apparently lowers the thermodynamic heat values and thus enhances the reversible hydrogen storage behavior at moderate te...

Conventional (e.g. MgH2) and complex hydrides (e.g. alanates, borohydrides, and amides) are the two primary classes of solid-state hydrogen-storage materials. Many of these “high-density” hydrides have the potential to store large amounts of hydrogen by weight (up to 18.5 wt% for LiBH4) and/or volume (up to 112 gL!1 for MgH2), values that are comparable to the hydrogen content of gasoline (15.8...

Rapid formation of magnesium hydroxide passivation layer during hydrolysis MgH2 seriously blocks its application as a hydrogen generation material. is also susceptible to oxidation. with Nb2O5 and/or CeO2 doping has been prepared via high energy ball milling in this work the aim enhancing performance and oxidation resistance. The phase compositions, microstructure evolution properties have syst...

We examined the catalytic effect of nanoparticle 3d-transition metals on hydrogen desorption (HD) properties of MgH(2) prepared by mechanical ball milling method. All the MgH(2) composites prepared by adding a small amount of nanoparticle Fe(nano), Co(nano), Ni(nano), and Cu(nano) metals and by ball milling for 2 h showed much better HD properties than the pure ball-milled MgH(2) itself. In par...

The stability of MgH2 has been studied up to 20 GPa using density-functional total-energy calculations. At ambient pressure alpha-MgH2 takes a TiO2-rutile-type structure. alpha-MgH2 is predicted to transform into gamma-MgH2 at 0.39 GPa. The calculated structural data for alpha- and gamma-MgH2 are in very good agreement with experimental values. At equilibrium the energy difference between these...

Hydrogen storage systems based on the combination reactor concept are promising for application of future complex hydride materials with high storage capacities and low reaction kinetics at moderate operating temperatures. In such a reactor, a fast reacting metal hydride is added to a complex hydride material in a separate compartment of the tank combining the advantages of the high storage cap...

The effects of HfCl4 and FeCl3 addition on the de/rehydrogenation properties of MgH2 were investigated. Both HfCl4 and FeCl3-doped MgH2 samples started to released hydrogen at about 270 °C, a decreased of about 70 °C and about 140 °C compared to as-milled and as-received MgH2, respectively. In terms of the desorption kinetics, the HfCl4-doped MgH2 sample showed significant improvement, with 6.0...

Reaction between a β-diketiminato magnesium hydride and carbon monoxide results in the isolation of a dimeric cis-enediolate species through the reductive coupling of two CO molecules. Under catalytic conditions with PhSiH3 , an observable magnesium formyl species may be intercepted for the mild reductive cleavage of the CO triple bond.