Hydrogen: the future energy carrier.

Since the beginning of the twenty-first century the limitations of the fossil age with regard to the continuing growth of energy demand, the peaking mining rate of oil, the growing impact of CO2 emissions on the environment and the dependency of the economy in the industrialized world on the availability of fossil fuels became very obvious. A major change in the energy economy from fossil energy carriers to renewable energy fluxes is necessary. The main challenge is to efficiently convert renewable energy into electricity and the storage of electricity or the production of a synthetic fuel.

Low-temperature synthesis of LiBH4 by gas-solid reaction.

The solvent-free synthesis of LiBH(4) from LiH in a borane atmosphere at 120 degrees C and ambient pressures is demonstrated. The source of borane is a milled LiBH(4)/ZnCl(2) mixture, in which Zn(BH(4))(2) is generated by a metathesis reaction. The yield of the reaction of about 74 % LiBH(4) shows that a bulk reaction is taking place upon borane absorption by LiH.

Stability and reversibility of LiBH4.

LiBH4 is a complex hydride and exhibits a high gravimetric hydrogen density of 18.5 wt %. Therefore it is a promising hydrogen storage material for mobile applications.

Nb2O5 "pathway effect" on hydrogen sorption in Mg.

In the present work we investigate the hydrogen sorption mechanism in a MgH(2)/Nb(2)O(5) composite and analyze why Nb(2)O(5) could strongly improve hydrogen sorption kinetics in magnesium. Hereby we make use of the fact that Nb(2)O(5) nanoparticles are able to reduce the milling time significantly with the achievement of excellent sorption kinetics, and can so exclude effects occurring at long-term milling that make difficult the study of the mechanism. On the basis of extensive chemical, crystalline, and microstructural characterization of the MgH(2)/Nb(2)O(5) nanopowder system, a "pathway model" is proposed, which explains the kinetic hydrogen sorption improvement by a formation of pathways of niobium oxide species with lower oxidation state that facilitate the hydrogen transport into the sample.