FTIR spectroscopic evidence of formation of geminal dinitrogen species during the low-temperature N-2 adsorption on NaY zeolites

Adsorption of N-2 on NaY zeolites at 85 K and equilibrium pressures higher than 1 kPa results in the formation of geminal dinitrogen complexes charact erized by an IR band at 2333.5 cm(-1) (2255.4 cm(-1) after adsorption of N- 15(2)). With decreasing equilibrium pressure the complexes tend to loose on e N-2 ligand, thus forming linear species characterized by an IR band at 23 36.8 cm(-1) (2258.7 cm(-1) after adsorption of N-15(2)). All species disapp ear completely after evacuation. Co-adsorption of N-2 and CO revealed that the dinitrogen complexes are formed on Na+ cations. The changes in the conc entrations of the linear and geminal N-2 species with the changes in the eq uilibrium pressure are excellently described by equations of adsorption iso therms proposed earlier for mono- and di-carbonyls.