Reversible CO 2 storage and efficient separation using Ca decorated porphyrin-like porous C 24 N 24 fullerene: a DFT study.

The search for novel materials for effective storage and separation of CO 2 molecules is a critical issue for eliminating or lowering this harmful greenhouse gas. In this paper, we investigate the potential application of a porphyrin-like porous fullerene (C 24 N 24 ) as a promising material for CO 2 storage and separation using thorough density functional theory calculations. The results show that CO 2 is physisorbed on bare C 24 N 24 , implying that this material cannot be used for efficient CO 2 storage. Coating C 24 N 24 with Ca atoms, on the other hand, can greatly improve the adsorption strength of CO 2 molecules due to polarization and charge-transfer effects. Furthermore, the average adsorption energy for each of the maximum 24 absorbed CO 2 molecules on the fully decorated Ca 6 C 24 N 24 fullerene is -0.40 eV, which fulfills the requirement needed for efficient CO 2 storage (-0.40 to -0.80 eV). The Ca coated C 24 N 24 fullerene also have a strong potential for CO 2 separation from CO 2 /H 2 , CO 2 /CH 4 , and CO 2 /N 2 mixtures.