Yttrium-dispersed B

We report a first-principles study, which predicts that a single yttrium atom decorated on B80 fullerenes can maximally hold up six H2 molecules with an average binding energy of $-0.55\ \text{eV}/\text{H}_{2}$ . The analysis with 12 Y atoms placed at the pentagons of B80 fullerenes showed no clustering effect, and the resulting B80Y12 complex can remarkably bind up to 71 H2 molecules, yielding a gravimetric storage capacity of 6.85 wt%. The interaction between hydrogen molecules and B80Y12 complex is attributed to the Dewar-Kubas mechanism involving the empty $\text{Y}\text{-}d$ orbitals, $\text{H}_{2}\text{-}\sigma$ orbitals and $\text{H}_{2}\text{-}\sigma^{*}$ antibonding orbitals. Our work suggests a new route to better hydrogen storage material and advances our fundamental understanding of reversible hydrogen adsorption in nanostructures