title: Catalytic mechanism of transition-metal compounds on Mg hydrogen sorption reaction.
abstract: The catalytic mechanisms of transition-metal compounds during the hydrogen sorption reaction of magnesium-based hydrides were investigated through relevant experiments. Catalytic activity was found to be influenced by four distinct physico-thermodynamic properties of the transition-metal compound: a high number of structural defects, a low stability of the compound, which however has to be high enough to avoid complete reduction of the transition metal under operating conditions, a high valence state of the transition-metal ion within the compound, and a high affinity of the transition-metal ion to hydrogen. On the basis of these results, further optimization of the selection of catalysts for improving sorption properties of magnesium-based hydrides is possible. In addition, utilization of transition-metal compounds as catalysts for other hydrogen storage materials is considered.
authors.affiliation: Institute for Materials Research, GKSS Research Centre Geesthacht GmbH, D-21502 Geesthacht, Germany. Gagik.Barkhordarian@gkss.de
authors.forename: Gagik
authors.initials: G
authors.lastname: Barkhordarian
authors.forename: Thomas
authors.initials: T
authors.lastname: Klassen
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Bormann