Main Applications and Prospects

As mentioned earlier in this chapter, it is the social demands and wide applications of porous materials that keep them under continuous exploration. From natural zeolites to synthesized ones, from low-silica zeolites to high-silica ones, from aluminosilicate molecular sieves to aluminophosphate-based ones, from extra-large microporous materials to mesoporous materials, and from inorganic porous frameworks to MOFs, together with newly emerging macroporous materials, all these porous materials have ordered and uniform porous systems. 

we would like to take ZSM-5 as an example to illustrate the relationship between structure and function. ZSM-5 has an interconnected 2-D 10-membered-ring channel system ([100] 10 5.1 x 5.5 - [010] 10 5.3 x 5.6 ). Since the Si/Al ratio of ZSM-5 can be varied from 10 to infinity as found in pure-silica silicalite-I, the type, acidity, and distribution of acidic sites can also be controlled accordingly. Furthermore, because of its special channel system, ZSM-5 may function very differently for different molecules. For example, the diffusion, the adsorption/desorption, the reaction rate, and the formation of intermediate and final product of molecules may vary to a great extent. ZSM-5 has been widely used in petroleum refining as a catalyst with good shape-selectivity. 

Since 1950s, there have been three traditional fields of application for molecular sieves and porous materials 1) separation, purification, drying and environment treatment process 2) petroleum refining, petrochemical, coal and fine chemical industries 3) ion-exchange, detergent industry, radioactive waste storage, and treatment of liquid waste. In addition to the traditional application fields, zeolites and related porous materials may also find applications in new areas such as microelectronics and molecular device manufacture. 

1 The Traditional Fields of Application and Prospects of Microporous Molecular Sieves 

According to Marcilly s proposal in 2001, in the next 20 years, there will be several new application fields in petroleum refining and petrochemical industries [19] 

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