Nitrogen physisorption on defective C60

Nitrogen physical adsorption, from 50 up to 120 K, on a defective C-60 fullerene solid is studied with Grand Canonical Monte Carlo computer simulations. New adsorption sites are produced due to the creation of a vacancy in the fcc crystal structure of C-60. The distributions of molecules with respect to their gas-solid and gas-gas interaction energies are analyzed. The contribution of the internal cavity of the solid to the total surface area is estimated from the local isotherms. The adsorbate cross-sectional area is calculated at all temperatures. The isosteric heat of adsorption is calculated from the Henry's Law constant. The adsorption energy distribution functions are discussed comparing the simulation results with experimental isotherms.