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

Abstract

Hydrogen molecules adsorption and storage in Sc coated Si@Al(12) cluster were investigated using density functional theory methods. Scandium atoms can bind strongly to the surfaces of Si@Al(12) due to the charge transfer between Sc and Si@Al(12), and do not suffer from clustering on the substrate. Si@Al(12) cluster coated with three and four Sc atoms can adsorb 16 and 18 H(2) molecules with a binding energy of 0.28-0.63 eV/H(2), corresponding to hydrogen storage capacity of 6.0 and 6.3 wt %, respectively. The stable Si@Al(12) can be applied as one of candidates for hydrogen storage materials at ambient conditions.