Chemisorption of hydrogen on a V5+ cluster

The binding between V5+ and hydrogen is studied by collision induced dissociation of the cluster-adsorbate V5+H2. Vanadium clusters are produced by laser vaporization and injected into an electromagnetic ion trap. After mass separation of V5+, the pulsed addition of hydrogen yields V5+H2. The desorption of hydrogen is studied by acceleration of V5+H2 with variable rf voltages and collisions with argon atoms. From the threshold voltage necessary for dissociation a binding energy of H2 on V5+ of 2.4 ± 0.3 eV is estimated. This value is consistent with a dissociative chemisorption of hydrogen.