Sc-coated Si@Al12 as high-capacity hydrogen storage medium

Hydrogen molecules adsorption and storage in Sc coated Si@Al12 cluster were investigated using density functional theory methods. Scandium atoms can bind strongly to the surfaces of Si@Al12 due to the charge transfer between Sc and Si@Al12, and do not suffer from clustering on the substrate. Si@Al12 cluster coated with three and four Sc atoms can adsorb 16 and 18 H2 molecules with a binding energy of 0.28–0.63 eV/H2, corresponding to hydrogen storage capacity of 6.0 and 6.3 wt %, respectively. The stable Si@Al12 can be applied as one of candidates for hydrogen storage materials at ambient conditions.