T. Klassen, Helmut Schmidt University, Hamburg, Germany; G. Barkhordarian, P. A. Huhn, M. Dornheim, R. Bormann, GKSS Research Center, Geesthacht, Germany
In view of increasing pollution and exploitation of
fossile fuel reserves, renewable energy concepts are essential for the future
of our society. Hydrogen is the ideal clean energy carrier, e.g. for the
zero-emission vehicle. Light metal hydrides, e.g. Mg or Alanates, are
interesting alternatives for reversible storage of hydrogen. Nanocrystalline microstructures and
suitable catalysts facilitate reversibility and good absorption and desorption
kinetics. The aim of this presentation is to elucidate the particular advantages
of nanocrystalline microstructures and to give tentative rules for good
catalyst materials, which may also apply for other hydrides or hydrogen
reactions. Experimental sorption curves for different catalysts and
microstructures were fitted on the basis of kinetic models and discussed
regarding the respective processes. Best kinetics is obtained for MgH2
with 0.5 mole% Nb2O5. Both, absorption and desorption are
possible within 2 minutes at 300°C and a desorption rate of about 100 kW/kg was
obtained.
Light metal hydrides, e.g. Mg or Alanates, are promising for hydrogen storage in zero-emission vehicles. We aim to elucidate the mechanisms of hydrogen reaction. In particular, advantages of nanocrystalline microstructures and tentative rules for good catalysts will be discussed, which may also apply for other hydrogen reactions.
