New Directions in Zeolite Catalysis

Abstract

Summary It is likely that the catalytic performance of a much broader variety of zeolites and related microporous materials will be routinely scrutinized in the nineties. In shape selective catalysis, reactions of larger molecules will play an increasing role. Even in petroleum refining and the manufacture of commodity petrochemicals, there is room for novel applications of zeolite catalysts. Two examples, viz. dewaxing by isomerization and isobutane/butene alkylation are discussed in some detail. The use of zeolite catalysts for the synthesis of organic intermediates and fine chemicals continues to be a thrust area. It is desirable that synthetic organic chemists routinely employ molecular sieve catalysts. Stereoselective catalysis in zeolites is still an underdeveloped field. The same holds for base catalysis in zeolites, especially shape selective base catalysis, but new approaches can be perceived in this area. Coupling of the exothermic MTO process and the endothermic hydrocarbon cracking on ZSM-5 type catalysts allows an almost thermoneutral production of lower olefins. The role of zeolites as hosts for a variety of guests is recognized by an ever increasing number of researchers. Ship-in-the-bottle catalysts or shape selective photochemistry are just a few examples for host/guest chemistry in zeolites.