Structures and electronic properties of WmCunH2 (m+n ≤ 7) clusters

Geometric and electronic structures of WmCunH2 (m + n ≤ 7) clusters have been systematically calculated by density functional theory (DFT) at the generalized gradient approximation (GGA) level for ground-state structures. For all W–Cu clusters, H atoms prefer to attach to W atoms in this system during adsorption. And more electrons transfer from H atom to W atom with the growth of the size of the cluster which benefits the hydrogen storage. Analysis of stability properties and electronic properties shows that hydrogen adsorption and dissociation process take place more efficiently at the W2Cu3H2 cluster than the others. Due to high thermodynamic stability and adsorption energy of W5CuH2 cluster among WmCunH2 (m + n ≤ 7) clusters, W5Cu is more suitable for hydrogen storage.