Ordered microporous and mesoporous materials with inorganic hosts: definitions of terms, formula notation, and systematic classification

Terms are defined which are related to ordered microporous and mesoporous materials with inorganic host structures of all kinds (poroates), and a notation for writing crystal–chemical formulae of these poroates is proposed. Both terms and notations have been developed on the basis of a systematic classification. The classification is based on the atomic structure and the chemical composition of the host and on the size and shape of its pores. Classification parameters are chosen such that the classification reflects relationships between structurally, chemically, and technologically relevant aspects, such as exchange, separation, catalytic, and enclathration properties of these poroates. A list of parameters provides for almost any amount of structural and chemical information to be derived from the general crystal–chemical formula. For practical purposes, however, this rather intricate formula can and should be simplified considerably by omitting those parameters that are irrelevant for the problem under consideration. The terms defined and the formula notation derived here are the basis of a nomenclature of structural and compositional characteristics of ordered microporous and mesoporous materials with inorganic hosts which is proposed by the IUPAC.