BASE AND ACID SITES IN ALKALINE-EARTH CATION-EXCHANGED X-ZEOLITES

Citation
J. Xie et S. Kaliaguine, BASE AND ACID SITES IN ALKALINE-EARTH CATION-EXCHANGED X-ZEOLITES, Catalysis letters, 29(3-4), 1994, pp. 281-291
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry Physical
Journal title
ISSN journal
1011-372X
Volume
29
Issue
3-4
Year of publication
1994
Pages
281 - 291
Database
ISI
SICI code
1011-372X(1994)29:3-4<281:BAASIA>2.0.ZU;2-N
Abstract
Alkaline earth exchanged X zeolites are characterized by pyrrole chemi sorption using FTIR spectroscopy. Lewis basic, Lewis acidic (cations) and also Bronsted acidic sites were detected in these zeolites. Based on a local environmental model, the charges on oxygens (basic sites) a nd cations are further calculated using the electronegativity equivale nce method. The NH stretching frequencies of pyrrole chemisorbed on bo th basic and acidic sites are well correlated with these charges. This relationship supports the early idea that the alkaline earth cations in faujasite exist in the form of (MOH)1+.