title: Hydrogen multicenter bonds and reversible hydrogen storage.
abstract: A new strategy for reversible hydrogen storage based on the properties of hydrogen multicenter bonds is proposed. This is demonstrated by carrying out ab initio calculations of hydrogen saturation of titanium and bimetallic titanium-aluminum nanoclusters. Hydrogen saturation leads to the formation of exceptionally and energetically stable hydrogen multicenter bonds. The stabilization results from sharing of the hydrogen atom electron density with the frontier orbitals of the metal cluster. The strength of the hydrogen multicenter bonds can be modulated either by varying the degree of hydrogen loading or by suitable alloying. Mode-specific infrared excitation of the vibrational modes associated with the multicenter hydrogen bonds can release the adsorbed hydrogen, thereby enabling efficient reversible hydrogen storage. The possible formation of hydrogen multicenter bonds involving titanium atoms and its implication to hydrogen adsorption/desorption kinetics in hydrogen cycled Ti-doped NaAlH(4) is also discussed.
authors.affiliation: Department of Chemistry, University of Nevada Las Vegas, 4505 Maryland Parkway, Las Vegas, Nevada 89154, USA. tarakesh@unlv.nevada.edu
authors.forename: P
authors.initials: P
authors.lastname: Tarakeshwar
authors.forename: T J Dhilip
authors.initials: TJ
authors.lastname: Kumar
authors.forename: N
authors.initials: N
authors.lastname: Balakrishnan