Siberian Federal University

Physisorption of molecular hydrogen in the pores of carbon nanomaterials is a well-known method for hydrogen storage. In this paper, we use several theoretical methods to investigate the problem of introducing hydrogen into single-walled carbon nanotubes (SWCNTs), which can be considered as model cylindrical pores. To study the interaction of molecular H2 with SWCNTs, density functional theory (DFT) calculations, symmetry- adapted perturbation theory (SAPT0) and three- dimensional visualization of non- covalent interactions within the framework of the independent gradient model (IGM) were used. It was found that the maximum values of interaction energy (Eint) correspond to the adsorption of hydrogen in SWCNTs of smaller diameter. By decomposing the energy Eint into physically significant components, it was determined that dispersion interactions (Edisp) make a dominant contribution to the attractive energy between H2 and SWCNTs. The second most important contribution is the electrostatic interactions (Eel), while induction interactions (Eind) make a minor contribution to the interaction energy. The introduction of hydrogen molecules into the studied SWCNTs was barrier-free. We believe that the results obtained are important for further study and development of new porous carbon materials for hydrogen storage