Na decorated B6 cluster and its hydrogen storage properties

The structures and hydrogen storage properties of sodium atoms decorated B-6 clusters are investigated by the B3LYP method with a 6-311+G (d, p) basis set. For NamB6 (m = 1-3) clusters, Na atoms are always inclined to separate far enough from each other and not cluster together on a B-6 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 B-6 cluster is 17.91 wt% with an adsorption energy per H-2 molecule (AAE/H-2) of 0.6851 kcal.mol(-1). The appropriate AAE/H-2 and preferable gravimetric density of the two Na atoms decorated B-6 cluster complex indicate that it is feasible for hydrogen storage application in ambient conditions.