Adsorption of Gases on Fullerene-like X<sub>12</sub>Y<sub>12</sub> (X = Be, Mg, Ca, B, Al, Ga, C; Y = C, Si, N, P, O) Nanocages
Remya Geetha Sadasivan Nair, Arun Kumar Narayanan Nair, Shuyu Sun
Abstract
Density functional theory calculations are carried out to investigate the adsorption behaviors of CO 2, NO, CO, and NH 3 on 12 fullerene-like X 12 Y 12 (B 12 N 12, Al 12 N 12, Ga 12 N 12, B 12 P 12, Al 12 P 12, Ga 12 P 12, Be 12 O 12, Mg 12 O 12, Ca 12 O 12, C 12 Si 12, C 12 N 12, and C 24 ) nanocages. The molecular electrostatic potential (MESP) analysis suggests that, for example, for the B 12 N 12, Al 12 N 12, and Ga 12 N 12 nanocages, the electron-rich regions are centered on the N atoms. The deepest MESP minimum ( V min ) values suggest that replacement of C atoms in C 24 by XY units increases the electron-rich nature of the nanocage. Generally, CO 2 is found to be physisorbed, while NH 3 is chemisorbed on the X 12 Y 12 nanocages. NO is found to be strongly adsorbed on the B 12 P 12, Be 12 O 12, Ca 12 O 12, and C 24 nanocages, and CO is strongly adsorbed on the B 12 N 12, B 12 P 12, Be 12 O 12, and C 24 nanocages. An important result is that the V min values of the X 12 Y 12 nanocages are linearly proportional to their CO 2 or NO adsorption energies. The quantum theory of atoms in molecules analysis suggests strong covalent interactions in the CO 2 /Ca 12 O 12, NO/Ca 12 O 12, NO/C 24, CO/C 24, and NH 3 /C 24 systems.