INDIUM AND GALLIUM CONTAINING ZSM-5 ZEOLITES - ACIDITY AND CATALYTIC ACTIVITY IN PROPANE TRANSFORMATION

Surface acidity and propane transformation on In- and Ga-containing ZS M-5 type zeolites were investigated to find relation between the acidi c character of catalysts prepared by conventional or solid state ion-e xchange and the catalytic activity in alkane aromatization. On the bas is of the concentration of Bronsted and Lewis acid sites measured by I R spectroscopy the In and Ga containing samples may be ordered into th ree main groups. The presence of Bronsted acid sites results in cracki ng of the hydrocarbon molecules, whereas the aromatization activity is attributed to Lewis acidity associated with the intimate contact of t he oxide/zeolite assemblies.