Catalytic activity in relation to acidic properties of acid-treated Egyptian clays

Abstract

Egyptian kaolinite and montmorillonite clays are subjected to acid treatment. The surface areas of the treated samples have been determined by nitrogen adsorption at - 196°C, the number of OH groups by ignition at 1200°C, and the acidic properties by pyridine adsorption in the temperature range 150-400°C. The catalytic cracking of cumene and conversion of isopropanol on the original and acid-treated clays have also been investigated. A fraction of the OH groups is found to be inactive for both cracking and dehydration reactions. The cumene cracking activity is related to the number of acid groups/cm2 and is sensitive to acid strength. Isopropanol dehydration is related to the total acidity and is less sensitive to the strength of the acid sites.