Sugunan, S; Rahna, K S(Indian Journal of Chemistry, July , 2002)
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Abstract:
The incorporation of transition metal oxide pillars such as those of iron and chromium along with Al2O3, pillars within
the interlayers of a montmorillonite clay is investigated. The surface acidity of these catalysts has been evaluated for the first
time employing the equilibrium adsorption of an electron donor, perylene, and the results are compared with those obtained
by temperature programmed desorption of ammonia. The principle is based on the ability of a catalyst surface site to accept
a single electron from an electron donor like perylene to form charge transfer complexes and the amount of adsorbed species
is measured quantitatively by UV-vis spectroscopy. Fina1ly, an attempt has been made to correlate the acidity determined by
the two independcnt methods and the catalytic activity of present systems in the benzoylation of toluene with benzoyl
chloride. Incorporation of Fe and Cr has changed the properties of AI pitlared montmorillonite. Fe pillared systems have
been found to be vcry good catalysts for benzoylation reaction