Hydrogen adsorption on 3d transition-metal-doped organosilica complexes

The adsorption of H2 on a series of 3d transition-metal (TM)-doped organosilica complexes is investigated using density functional calculations. We show that a modified benzene-silica (MBS) model with the 3d TM atoms can adsorb H2 as dihydride or dihydrogen configurations except the model with Fe, Co, or Ni, which can store hydrogen as dihydrogen forms only. The maximum numbers of H2 molecules adsorbed are one to three for the various TM atoms, with the average binding energies of 0.4–0.9 eV. We propose that the TM–MBS (TM = Sc, Ti, and V) complexes can be the building blocks in designing hydrogen storage materials.