ABSTRACT
I. ZEOLITES
Zeolites are crystalline aluminosilicates built up from a framework of silicon and aluminium ions interconnected via oxygen ions. The silicon and aluminium ions are tetrahedrally coordinated to oxygen atoms to produce a three-dimensional aluminosilicate network that results in the formation of channels or cavities in which are located hydrated alkali metal cations balancing the negative charge on each aluminium-oxygen tetrahedron. An example of this is shown in Fig. 1, where the three-dimensional diamond-type structure of the zeolite faujasite is clearly seen.
