Adsorption of gases on benzene-preplated graphite

Abstract We measured volumetrically adsorption isotherms of N 2 , Ar, CH 4 , and Kr on benzene-preplated graphite at 77 K. N 2 and Ar exhibit a new step on the isotherm at 5.0 and 4.3 Torr, respectively, suggesting some phase transition of the gases adsorbed on a single layer of benzene. On the other hand, CH 4 and Kr show layerwise condensation transitions even when one monolayer of benzene is preadsorbed, implying that benzene is displaced by these gases, but to the smallest extent among those observed previously for other systems. Benzene is also found to be soluble in N 2 , Ar, and Kr.