Reversible hydrogen storage capacity of vanadium decorated small boron clusters (BnV2, n=6-10): A dispersion corrected density functional study

We present our theoretical investigation on hydrogen storage capacity of vanadium decorated small boron clusters (BnV2, n = 6-10) employing dispersion-corrected density functional theory. Stabilities of the clusters during H2 adsorption are confirmed from the global reactivity parameters. BnV2 clusters are found to adsorb up to ten H2 molecules in quasi-molecular form via Kubas-Niu-Rao-Jena kind of interactions with average adsorption energy in the range of 0.17-0.26 eV/H2. ADMP molecular dynamics simulation reveals the thermal stability, structural integrity and reversibility of BnV2, n = 6-10 at room temperature (300 K). The maximum practical hydrogen storage capacity at temperature up to 80 K and pressure ranges of 1-60 bar are found to store up to 8.75-10.78 wt% which is well above the target set by US-DOE (5.5 wt% by 2025). The results obtained from our investigations assure the potential of vanadium decorated small boron clusters for reversible hydrogen storage.