First-principles study of Pd-decorated carbon nanotube for hydrogen storage

Based on first-principles plane wave calculations, we investigated the hydrogen adsorption on Pd-decorated single-walled carbon nanotubes (SWCNT). Our calculations revealed that the most hydrogen storage capacity is 2.88 wt.% with an average binding energy 292 meV for the uniformly Pd-decorated SWCNT, which is in good agreement with the experimental measurement. The electrostatic Coulomb attraction and the orbital repulsion mediate the interaction between H2 and Pd. Our results predicted the binding energy and the hydrogen storage capacity can be further enhanced by using the open-shell transition metal/SWCNT media.