Main application fields and development prospects of mesoporous materials
Since the synthesis of MCM-41 ordered mesoporous materials by scientists at Mobil Corporation in 1992, a great deal of research has been devoted to their potential applications. In these studies, people mainly focus on their catalysis, adsorption and preparation of new high-tech advanced functional materials, etc. Among them, the application of catalytic materials with mesoporous structure is more concerned.
The structure and physical and chemical properties of ordered mesoporous materials are unique, which are manifested in their large specific surface area, generally greater than 1000m2/g; the mesoporous pore size is uniform, and its pore size varies between 2 and 50pm.
Due to the high specific surface area of mesoporous materials, it is conducive to the construction of sufficient surface active sites. The uniform size of the pores provides a good nano-confined space. The diversity expands the application of mesoporous materials in various types of catalytic reactions, especially macromolecular catalytic reactions.
According to whether the framework of mesoporous materials has
catalytic activity, mesoporous materials are often divided into two types. For
mesoporous materials whose framework does not have catalytic activity,
catalytically active components can be introduced into the pores of the
mesoporous material by guest loading, surface grafting, surface coating or
framework doping, so as to endow the mesoporous material with catalytic
activity. Compared with the assembly of guests in microporous channels, it has
higher specific surface area and larger channel space, which can assemble
larger, more complex and more types of guest molecules, and has more smooth diffusion
and transport of reactants and intermediate molecules. channel.
Therefore, mesoporous catalytic materials are often divided into the
following three types: (1) Mesoporous materials are used as host materials with
high specific surface area and ordered pore structure, and guests with high
dispersity catalytic activity are loaded to obtain host-guest catalytic
materials; (2) The framework of mesoporous material itself has no catalytic
activity. After framework substitution or surface functionalization, the
catalytic activity is achieved, which is referred to as functionalized
mesoporous catalytic material. It is a functional mesoporous catalytic
material.
