Zeozymes , encapsulated catalysts

Encapsulation of enzyme active sites in the intracrystalline pore volume of zeolites and molecular sieves is possible and sterically induces selectivity in oxygenation as well as in hydrogenation reactions. We denote the new catalysts, generated as result of a host-guest interaction between the zeolite (host) and the complex (guest) as ZEOZYMES, a family of materials which can function as supramolecular catalysts. 

The application of zeolite encapsulated metal chelate complexes in catalysis is a promising area of research. In particular shape selective oxidations catalyzed by metallophthalocyanines (MPc), shown in Figure 1, included in synthetic faujasite (FAU) type zeolites (2-10) appear to be competitive with other molecular sieve based catalysts that may have commercial potential. The restricted apertures ( 7.4 A) to the supercages (12A) in FAU type zeolites precludes removal of the large MPc complex unless the zeolite lattice is destroyed. Such physically trapped complexes have been termed ship-in-a-bottle complexes as well as zeozymes (to reflect the biomimetic reactivity that is often associated with these catalysts). 

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