Influence of Pt decoration on the hydrogen storage performance of cup-stacked carbon nanotubes: A DFT study

The hydrogen adsorption behaviour of cup-stacked carbon nanotubes (CSCNTs) decorated with the platinum atom at four positions of the conical graphene layer (CGL) is investigated using density functional theory. The optimization shows that the inside lower edge position (IL) results have the best hydrogen adsorption parameters among the four positions. The Pt-H-2 distance is 1.54 angstrom, the H-H bond length (l(H-H)) is 1.942 angstrom, and the hydrogen adsorption energy (E-ads) is 1.51 eV. The hydrogen adsorption of CSCNTs decorated by Pt at the IL position also has larger E-ads and l(H-H) than the Pt-doped planar graphene, Pt-doped single-wall carbon nanotubes and Pt-doped carbon nanocones. The Pt atom at the IL position has a more significant polarization effect on the adsorbed H-2, it has trends to convert H-2 into two separate H atoms. While the hydrogen adsorption behaviour at other positions belongs to the Kubas coordination, the l(H-H) and the Eads increased not significantly. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The hydrogen adsorption behavior of cup-stacked carbon nanotubes decorated with platinum atoms at different positions of the conical graphene layer was investigated. The optimization results showed that the inside lower edge position had the best hydrogen adsorption parameters. The hydrogen adsorption at this position exhibited larger adsorption energy and bond length compared to other positions, and the platinum atom at this position had a significant polarization effect on the adsorbed hydrogen molecules.