Ultrasonication: A competitive method of intercalation for the preparationof alumina pillared montmorillonite catalyst

A Ca2+-montmorillonite clay has been pillared with aluminium hydroxy polyca tions using ultrasonic technique. This pillared clay is compared with that obtained by conventional method of pillaring. XRD, FTIR in the framework re gion and surface area measurements elucidate that ultrasonically achieved p illaring is very homogeneous as compared to conventional technique. The uni form pillaring is responsible for the enhanced thermal and hydrothermal sta bility. However, the use of ultrasonics does not alter the inherent propert ies such as acidity of the pillared clays, as indicated by IR spectroscopy of adsorbed pyridine. The catalytic activities in the decomposition of prop an-2-ol and cumene further confirms the strong acidity of the pillared clay s, obtained either by ultrasonic or conventional techniques. In the time on stream studies for both the reactions, slower deactivation was observed on pillared clay prepared by ultrasonication route. Thus, the pillared clay c an be obtained via., ultrasonication method of intercalation within 20 min at ambient temperature, with improved textural properties leading to higher stability of the material, without compromising on acidity or catalytic ac tivity of the pillared clay. (C) 1999 Elsevier Science B.V. All rights rese rved.