Hydrogen storage properties of hexagonal C14 Laves phase Cu2Cd: A DFT study

Hexagonal C14 Laves phase Cu2Cd (AB(2)) is metallic in nature, which is stabilized by Cu-Cd and Cd-Cd interactions. The compound could be used as a potential hydrogen storage material. Accordingly, using the density functional theory, hydrogen absorption properties of Cu2Cd were calculated. The electronic structures and chemical bonding in the compounds via crystal orbital Hamilton population analysis were also investigated. Different sites for the absorption of hydrogen were identified. The volume of the unit cell was observed to expand with an increase in H-loading in the compound with an increment as large as 13% by volume. The binding energies of H were found to be close to similar to 60 kcal/mol. Density of states of hydrogenated configurations showed a modification of the electronic structure after hydrogen absorption. Chemical bonding and Bader charge analysis revealed that the Cd-H interactions are noticeably stronger than the Cu-H interactions in the hydrogenated configurations.