Microporous framework solids definitions

The traditional definition of a zeolite refers to microporous, crystalline, hydrated aluminosilicates with a tliree-dimensional framework consisting of comer-linked SiO or AlO tetrahedra, although today the definition is used in a much broader sense, comprising microporous crystalline solids containing a variety of elements as tetrahedral building units. The aluminosilicate-based zeolites are represented by the empirical fonmila... 

The definition for catalytic purposes of a zeolite reads as follows a crystalline material with micropores and cation-exchange capacity that is insoluble in water and common organic solvents and has sufficient thermal stability that allows removal of all pore-filling agents present in the as-synthesized materials. This definition is narrower than that of the IZA Constitution, which includes mesoporous solids, metal organic frameworks (MOFs), cationic and anionic clays [3]. 

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