Application fields and development prospects of microporous molecular sieves

Application fields and development prospects of microporous molecular sieves

For half a century, molecular sieves have played an increasingly important role in petroleum processing, petrochemical and fine chemicals, and environmental chemicals as the main catalytic materials, adsorption separation materials and ion exchange materials. Nevertheless, the role of molecular sieves in the above three traditional fields still has great prospects for development. First, there are 213 molecular sieves with known structures so far (2013). Look, there is still a lot of room for development. However, so far, only A, X and Y faujasite, mordenite, ZSM-5, ZSM-11, MCM-22, L, B, erionite, RHO, CHA have been used on an industrial scale. , AEL type and TS, and less than twenty kinds of SAPO-34, SAPO-11, SAPO-31 and so on.

ZSM-5 molecular sieve

It is speculated that in the next two decades, due to the need for the development of fine chemicals and intermediate chemicals, as well as the renewal and development of traditional application fields of petroleum processing, petroleum processing and coal chemicals, the application of molecular sieves in catalysis and adsorption separation will be further promoted. great development in the field.

Secondly, in the past 20 years, due to the development of new catalysis fields of molecular sieves, such as base catalysis of molecular sieves, catalysis of ultra-large microporous molecular sieves, redox catalysis and chiral catalysis of molecular sieves, as well as the rise of micropore-containing hierarchical porous composite materials, more Advances in bifunctional and even multifunctional molecular sieve catalysts. This will provide a strong foundation for the further development of molecular sieves in the field of catalysis and adsorption separation.

Thirdly, due to the diversity and controllability of the above-mentioned structures and properties, a large number of advanced functional materials based on microporous substances have been developed and developed on this basis. open up.

The microporous host-guest composites can be classified into the following four categories according to the different assembling guest species. The first type is a composite system composed of a porous body and metal or metal clusters; the second type is a composite material formed by a porous body, a polymer and a carbon material, and the carbon material includes carbon nanotubes and fullerenes; the third type is mainly It is a host-guest composite material composed of functional nanoparticles such as inorganic semiconductors formed in the pores or cavity cages of the porous host; the fourth type is the porous host and organic molecules, metal complexes, cluster compounds, supramolecular drug molecules, etc. host-guest material. Considering the pore size of the host material, the size and properties of the guest molecules, different methods of assembly, grafting, anchoring, loading, etc. have been developed to prepare and synthesize a large number of composite guest materials with specific properties. Functions and types of membranes, nano-states, special morphologies and perfect crystals. These materials have developed and developed a large number of specific functions by virtue of the functions of highly dispersed guest species, or the synergistic effect of host and guest species, and formed a new scientific field with important development prospects.