A Monte Carlo simulation study of the effect of carbon topology on nitrogen adsorption on graphite, a nanotube bundle, C-60 fullerite, C-168 schwarzite, and a nanoporous carbon

摘要

The effect of carbon topology on nitrogen adsorption at zero coverage on a variety of carbonaceous materials: graphite, a nanotube bundle, C-60 fullerite, C-168 schwarzite, and a nanoporous carbon is studied systematically using full atomistic Monte Carlo simulations. The pairwise additive site - site Lennard-Jones potential of Bojan and Steele is used to model the carbon - nitrogen interaction of adsorbent - adsorbate. The Henry constant is found to increase in the order of graphite < nanotube bundle < C-60 fullerite < C-168 schwarzite < nanoporous carbon, and the isosteric heat of adsorption increases in the order of graphite < nanotube bundle < C-168 schwarzite < C-60 fullerite < nanoporous carbon. The latter order is consistent with the degree of curvature, as characterized by the carbon coordination number around nitrogen in favorable adsorption sites. With increasing temperature, the Henry constant significantly decreases on all the carbonaceous materials studied, while the isosteric heat remains nearly constant on graphite, nanotube bundle, and C-60 fullerite, decreases slightly on C-168 schwarzite, and to a greater extent on nanoporous carbon.