Effect of OH^-/Al ratio of pillaring solution on the texture and surface acidity of aluminium pillared clays

Abstract

A few alumina pillared montmorillonite clay samples have been prepared by varying OH^- /Al ratio of the crosslinking solution in the range of 1.5 to 1.9. Variations in OR-fAl ratio of cross linking solution has led to the different adsorption capacities of the pillared clays for nitrogen, water, benzene and pyridine adsorption isotherms. Pillared clay intercalated with crosslinking solution with OH^-/AI ratio of 1.7 shows highest adsorption capacity for water, benzene and pyridine. The nitrogen adsorption isotherms are of type-I indicating microporosity. Infrared spectra of pyridine adsorbed samples show that pillaring generates Lewis as well Bronsted type of acidity in the clays. After pillaring the number of accessible protons available on the surface of the clay is increased as compared to that in unpillared clay.