1995/12/01 by George H. Smudde, T.L. Slager, Charles G. Coe +2
Chemistry · Materials Science · Physics and Astronomy · #Catalytic Processes in Materials Science #Spectroscopy and Quantum Chemical Studies #Zeolite Catalysis and Synthesis
paper · doi:10.1366/0003702953965957
openalex publication_date 1995/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) and Raman spectroscopy were used to examine N 2 and O 2 adsorption on cation-exchanged (K, Na, Sr, Ca, and Li) low silica X (LSX) zeolites. IR and Raman absorption bands were observed for the molecular vibration of adsorbed N 2 and O 2 at room temperature and atmospheric pressure. The intensity (in Kubelka-Munk units) of the IR band increased with N 2 pressure and mirrored the adsorption isotherm for N 2 . Both O 2 and N 2 displayed a similar dependence of the molecular vibrational frequency on cation charge density, which suggests that both gases are interacting directly with the cations. The vibrational frequencies for adsorbed N 2 and O 2 were more sensitive to the cation charge density than to framework Al content. Infrared studies of N 2 and O 2 on mixed cation forms of LSX show that N 2 interaction was localized near individual cations within the sorption cavity of the zeolite. Thus, adsorbed N 2 can be used to probe accessibility of specific cations within the zeolite framework. The spectroscopic data are consistent with the theory that the stronger interaction of N 2 over O 2 is caused by the stronger influence of the electric field with the larger quadrupole of N 2 .