Molecular Interactions in Nanoporous Adsorbents. Adsorption of N2 and O2 in Zeolites with Cavities or Channels: Na12A, Ca6A, NaX, and Decationated Mordenite

The adsorption of two small molecules in porous crystals presenting void volumes of different shapes (cavities of ∼12 Å diameter, channels of ∼6 Å diameter) is measured in a large range of temperatures and pressures. The data analysis shows off the difference in the intermolecular forces between N 2 and O 2 molecules; in condensed phases the molecule−molecule interaction is repulsive and it is more repulsive for N 2 . The density of the adsorbed phase is compared with that of the liquid at three temperatures; that points out the confinement effect which is dominant in the channels.