Hydrogen binding energy of halogenated C40 cage: An intermediate between physisorption and chemisorption

In this work, the energetic of non hydrogenated and hydrogenated small mass fullerene cages with the view of assessing hydrogen storage capacity have been investigated. All calculations have been performed with the DFT as implemented within G03W package, using B3LYP exchange-functional and applying basis set 6-31G(d,p). Our calculations show that the C40 fullerene cage possesses high surface reactivity. For the first time, the hydrogen binding energy of halogenated C40 cage is calculated and it is found to be an intermediate between physisorption and chemisorption states. The 1H NMR, 13C NMR chemical shifts, FT-IR spectra and partial atomic charges have been performed for C40 and C60, C40H40 and C60H60 cages. In addition, the hydrogen storage capacity is found to be increased by doping the C40 cage with light elements. Hence halogenated C40 cage is considered to be good candidate for hydrogen storage.