Effect of metal and nonmetal on adsorption of hydrogen in torus-type C₁₂₀

Highlights: • The orbitals populations of torus-type C₁₂₀ are changed by substituted group. • The accumulate fields of H₂ are changed by metal or nonmetal modifications. • The hydrogen storage capacity of torus-type Li-C₁₂₀ is enhanced by Li. • The molecular frontier orbitals influence hydrogen storage properties of Li-C₁₂₀. The hydrogen adsorption properties for the torus-type C₁₂₀, and the changes of adsorption influenced by nonmetal and metal have been systematically investigated. The results show that, in the pristine torus-type C₁₂₀, the inner carbon atoms have more negative static potential than the outer ones. H₂ intends to accumulate at the area near inner carbon atoms. However, torus-type C₁₂₀ is modified by nonmetal (N and O) or metal (Li), the accumulated fields of H₂ are changed. Li can evidently enhance the hydrogen storage capacity. The most gravimetric density is predicted to be 7.21 wt% for the 8Li-C₁₂₀ in 77 K and 1200 kPa.