Na decorated B₆ cluster and its hydrogen storage properties

The structures and hydrogen storage properties of sodium atoms decorated B₆ clusters are investigated by the B3LYP method with a 6-311+G (d, p) basis set. For Na_mB₆ (m=1–3) clusters, Na atoms are always inclined to separate far enough from each other and not cluster together on a B₆ cluster surface so that each Na atom has sufficient space to bind hydrogen molecules. The hydrogen storage gravimetric density of a two Na atoms decorated B₆ cluster is 17.91 wt% with an adsorption energy per H₂ molecule (AAE/H₂) of 0.6851 kcal·mol^-1. The appropriate AAE/H₂ and preferable gravimetric density of the two Na atoms decorated B₆ cluster complex indicate that it is feasible for hydrogen storage application in ambient conditions.