Far Infrared Study of Cation Motion in Dry and Solvated Mono- and Divalent Zeolites X and Y.
Abstract
Far infrared ion motion bands have been observed and assigned in the spectra of dry synthetic zeolites X and Y containing Li+, Na+, K+, Rb+, Cs+, Ag+, Ca2+, Sr2+, and Ba2+ cations. The site I' and site II cation vibrational bands overlap and form the strongest feature in the spectra of samples exchanged with monovalent ions. The site I cation band appears at lower frequency than the site II envelope in these samples, but in divalent ion exchanged zeolites the opposite order occurs. A very low frequency site III cation band, typical of monovalent X zeolites, has been observed in CsY. For a given cation, the frequency on X is higher than on Y due to the higher framework charge of X zeolites. The vibrational frequencies also follow an approximate m raised to minus 1/2 power dependence for the two types of cation and the two forms of the zeolite. Solvation of the monovalent zeolites with H2O, THF, DMSO, pyridine, and CH2Cl2 results in the appearance of a new band at higher frequency than the ion-framework modes which concurrently diminish in intensity, especially the site III band. The high frequency band is due to ion motion in a solvation shell which is unsymmetric at low hydration levels and at all solvation levels with organic adsorbates.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 10, 1977
- Accession Number
- ADA038665
Entities
People
- Charles L. Angell
- Warren Mcallister
- Wayne M. Butler
- William M. Risen Jr
Organizations
- Brown University