This chapter investigates how N2 and 02 interact with different cations and to delineate how large is the role of a purely electrostatic effect in the adsorption process. To this end, the interactions of N2 and 02 with a positive point charge, with isolated Na+ or Li+ cations, with their dimers and with a small model cluster of zeolite have been analyzed and compared. Moreover, the role of the ionic nature of the zeolite structure around the adsorption cationic site has also been investigated, using the embedding of a large network of point charges. All these calculations are first-principle calculations, based on density functional theory (DFT). These quantum mechanical calculations on small model clusters including Li and Na cations have shown that the different N2 and 02 adsorption properties in zeolites may be explained by simple arguments. Indeed, they have demonstrated that a classical description involving electrostatic and induction energies, which depend on the quadrupole moment and dipole polarisability of these molecules repectively, is adequate to explain the basic reason for a stronger N2 adsorption.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry