Molecular Sieve Catalyst | Classification of molecular sieve catalysts

Molecular Sieve Catalyst

Molecular sieves are divided according to the size of the pores, and there are molecular sieves smaller than 2 nm, 2-50 nm and larger than 50 nm, which are called microporous, mesoporous and macroporous molecular sieves respectively. Molecular sieves can be divided into three categories according to the pore size: microporous, mesoporous and macroporous molecular sieves. Microporous molecular sieves have the advantages of strong acidity, high hydrothermal stability, and special "shape-selective catalysis" performance, but they also have disadvantages such as narrow pore size and large diffusion resistance, which greatly limit their application in macromolecular catalytic reactions. Mesoporous molecular sieves have the characteristics of high specific surface area, large adsorption capacity, and large pore size, which can solve the problem of mass transfer and diffusion to a certain extent. However, their weak acidity and poor hydrothermal stability limit their industrial applications. In order to solve the above problems, researchers have developed hierarchical porous molecular sieves, which combine the advantages of mesoporous and microporous molecular sieves and have immeasurable application prospects in the petrochemical field.