Y-type molecular sieves have a close-packed hexagonal structure similar to diamond. If the beta cage is used as the structural unit to replace the carbon atom nodes of the diamond, and the two adjacent beta cages are connected with hexagonal columnar cages, that is, the five beta cages are connected together with four hexagonal columnar cages, of which one beta cage is located in the center and the remaining four beta cages are located at the vertex of the tetrahedron, an octahedral zeolite crystal structure is formed. By continuing to link with this structure, the Y-type molecular sieve structure is obtained. In this structure, the large cage formed by the β cage and the hexagonal columnar cage is an eight-sided zeolite cage, and their interlinked window holes are twelve binary rings, whose average effective pore size is 0.74nm, which is the pore size of Y-type molecular sieve. X type molecular sieve and Y type molecular sieve structure is exactly the same, but Y type molecular sieve silica aluminum ratio is high, hydrothermal stability is strong, so it is more widely used.
