Research on hydrogen adsorption characteristics of Pt decorated cup-stacked carbon nanotubes

A kind of new carbon-based material called cup-stacked carbon nanotubes decorated by Pt atom (CSCNTs-Pt) is analyzed to hydrogen adsorption by density functional theory (DFT). The electron density difference, partial density of states, and electrostatic potential are used to display hydrogen adsorption behaviors on CSCNTs-Pt substrate. The optimization results show that only one hydrogen molecule can be chemically adsorbed by the polarization effect of Pt and the others are physically lateralized by Kubas interaction where H-H bond lengths of adsorbed hydrogen molecules are increased. Moreover, the hydrogen molecule near the end of the cone axis is hard to chemisorption due to curvature. Compared with planar graphene, single-wall carbon nanotubes, and nanocones, up to eight hydrogen molecules can be accommodated under the substrate because the ninth hydrogen molecule breaks original adsorption stability. With the increase of hydrogen molecules from one to eight, Pt electron transfer is promoted with enhanced orbital hybridization.

Automated summary

In this study, the hydrogen adsorption behavior on a new carbon-based material called CSCNTs-Pt was analyzed using DFT. The results showed that Pt decorated carbon nanotubes can achieve both chemical adsorption and physical bonding of hydrogen. Up to eight hydrogen molecules can be accommodated on the substrate, and the electron transfer of Pt is promoted with the increase of hydrogen molecule number.