Hydrogen storage on MgO supported TiMgn (n = 2–6) clusters: A first principle investigation.

The current study explores the potential of MgO-supported finite-sized TiMg n (n = 2–6) nanoclusters as hydrogen storage materials, employing density functional theory with a spin-polarized generalized gradient approximation (GGA). These systems' structural stability and electronic characteristics reveal that supported clusters offer superior hydrogen storage capabilities compared to their unassisted counterparts. Various parameters, including cluster-adsorption energy (E ads), hydrogen-adsorption energy in supported clusters (E ads -H), HOMO-LUMO gap, vertical ionization potential (VIP), vertical electron affinity (VEA), chemical potential (μ), and chemical hardness (ɳ) are computed. Substrate support notably enhances the thermodynamic stability and chemical reactivity of the TiMg 5 cluster when contrasted with the bare TiMg 5 cluster. Furthermore, a remarkable increase in the gravimetric hydrogen storage density, from 1.63 wt% for bare Mg 5 clusters to 3.45 wt% for bare TiMg 5 clusters, reaching 5.62 wt% in the supported TiMg 5 cluster system is observed. These findings indicate the substrate-supported TiMg 5 cluster as a promising candidate for hydrogen storage applications. [Display omitted] • Utilized DFT to investigate hydrogen storage capabilities of Mg n and TiMg n (n = 2–6) clusters supported on MgO. • Upon hydrogenation, Mg 5 and TiMg 5 clusters exhibited heightened chemical hardness, enhancing their resistance to reactions. • H 2 storage efficiency was credited to the plenty of reactive sites on the cluster's surface and the system's stability. • Achieved hydrogen gravimetric density of 5.62 wt% in supported TiMg 5 clusters through hydrogen adsorption. • Among different TiMg n clusters, supported TiMg 5 demonstrated superior efficiency in both hydrogen storage and dissociation. [ABSTRACT FROM AUTHOR]