SOLID-STATE AND CATALYTIC CHARACTERIZATION OF INTERGROWN ZEOLITE STRUCTURES BASED ON 6-MEMBERED RINGS

Zeolites CSZ have been synthesized from hydrogels containing sodium and caesium cations. At low gel caesium content, a predominantly Y-type zeolite is formed that is modified extensively when higher synthesis gel caesium contents are used. High-resolution transmission electron micrographs of a CSZ zeolite prepared from caesium rich gels show that the primary structural intergrowth coexisting with faujasite is Breck's structure 6. The aluminosilicate frameworks of the CSZ zeolites react differently to treatments with steam as observed by Si-29 magic angle spinning n.m.r. spectroscopy. The steamed zeolites, when tested by n-hexane cracking, have different acidities due to the presence of metal cations and due to the different spatial distributions of aluminum in the zeolite frameworks.