Faujasite (FAU) and its hexagonal analog (EMT) was investigated in the catalytic cracking of n-heptane. Measurements were conducted with Aerosil-200 bound catalysts in an integral fixed bed reactor at 723 K. Catalytic activity is related to the concentration of Bronsted acid sites of the zeolite framework. Catalytic behaviour of dealuminated and subsequently acid leached varieties evidences that extra-framework aluminium species formed during dealumination contribute to catalysis. The distribution within the spectrum of the products of reaction clearly demonstrates that pathways producing alkenes and free hydrogen are involved in the scission of the parent hydrocarbon.