Recent developments in catalysis by zeolites

Abstract

The catalysis of hydrocarbon cracking, isomerisation, alkylation, hydrogen transfer and related reactions, by zeolites has been extensively studied during the last two decades. Much of the work in this area has been carried out on faujasite and mordenite—type zeolites in their acidic forms. As a result of the enormous number of studies devoted to this subject a fair understanding of acid—catalysis by zeolites has resulted. Recently several excellent reports have reviewed the subject 11—71 . A characteristic feature of zeolites is their promoting effect in bimolecular reactions and their selectivity due to the shape of thc channels. The shape—selectivity has also been reviewed recently 8—10 I. More recently among the many branches of zeolite chemistry three topics have attracted the attention i.e. i) Since the discovery of a new class of zeolites called ZSM—5 or pentasil at Mobil Laboratories interest has been refocussed on shape selectivity catalysis by small pore zeolites of the mordenite or