Dependence of the properties of titanium-pillared clays on the host matrix: a comparison of montmorillonite, saponite and rectorite pillared materials

Abstract

Titanium pillared clays using montmorillonite, saponite and rectorite hosts have been prepared from TiCl 4 –ethanol solutions. The products have been characterised structurally by PXRD and IR studies and for acidity by cyclohexylamine and pyridine adsorption–desorption studies. Catalytic activity data for pentanol dehydration and cumene cracking are also presented. The amount of Ti incorporated is related to the cation-exchange capacity of the host. The thermal stability of the pillared material decreases from rectorite through montmorillonite to saponite. Cyclohexylamine desorption suggests that the saponite sample has the highest acidity, and this is reflected in the highest conversion for cumene cracking. In the case of pentanol dehydration, however, the highest activity is seen for the rectorite sample, despite its apparent lower acidity. Similar effects have been reported previously for this reaction with alumina pillared clays.