Infrared spectral characterization of acidity of zirconium pillared clays

Abstract

Montmorillonite and vermiculite intercalated with polyoxo cations of zirconium have been prepared. The nature of acidic sites has been studied by infrared (lR) spectroscopy using pyridine and ammonia as the probe molecules. The IR spectral data show three types of acid sites to be available on the pillared clay catalysts. The existence of Bronsted acid, lewis acid and weak acidic sites has been demonstrated. The effect of heat treatment on the intensities of IR spectral bands has been investigated to confirm the presence of weak acid sites to which pyridine is hydrogen bonded.