The influence of adsorbed molecules on the framework vibrations of Na-Faujasites studied with FT Raman spectroscopy

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 51; no. 12; pp. 2147 - 2159
• Main Authors: Ferwerda, R, van der Maas, J.H
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16-11-1995
• ISSN: 1386-1425
• DOI: 10.1016/0584-8539(95)01473-5

The use of FT Raman spectroscopy in the elucidation of the structural parameters of Faujasitic zeolites is investigated. Because fluorescence is less of a problem on excitation with a near-infrared laser, FT Raman spectroscopy allows one to probe the effects of in situ heat treatments on the zeolite structure. A correlation is found between the bending vibrations of the Y zeolites and their unit cell size. The vibrations, however, are severely influenced by the charge distribution within the zeolite. Hence, the position of the charge-balancing cations and the water content affect the Raman spectra. Pyridine adsorption results in a rearrangement of the cations or water molecules still present in the structure after activation, and thus alters the vibrations of the zeolite lattice.