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Y-type molecular sieves are microporous crystalline materials with a skeletal structure. The most basic structural units that make up this skeleton are silicoxy and aluminoxy tetrahedra, which form secondary structural units such as four-membered rings, six-membered rings, and eight-membered rings through Si-O or Al-O bonds. These secondary structural units then combine with each other to form β-shells. Eight β-cages are arranged in a diamond crystal structure; in this structure, each carbon atom is replaced by a β-cage. Adjacent β-cages are connected through six-membered rings composed of Si-O-Si(Al), forming octahedral zeolite cages. These octahedral zeolite cages are interconnected along the three crystal axes through twelve-membered rings, thereby forming a unit cell. The dodecahedral ring is the main pore of octahedral zeolites, with a pore size of approximately 0.74 nm. Figure 2: Crystal structure of Y-type molecular sieve 3.2 Synthesis of Y-type molecular sieve 3.2.1 Synthetic raw materials The main raw materials for synthesizing Y-type molecular sieve are silicon sources, aluminum sources, alkalis, and water. Common silicon sources include water glass and silica sols. Different silicon-containing compounds have a significant impact on the synthesis of certain zeolites; they affect not only the crystallization rate but also the quality of the product, and may even lead to unexpected results. Common aluminum sources include sodium aluminate, aluminum sulfate, aluminum oxide, etc. The type and purity of the aluminum source have a significant impact on the quality and physicochemical properties of the product. Y-type molecular sieves are synthesized in a certain alkaline environment, so an alkali must be present. Since the structural units that form zeolites have different stabilities at various alkali levels, zeolites synthesized under different alkali conditions are also different. Water has good dissolving capacity, which facilitates the mixing and movement of various components ； Water enables silicon- and aluminum-containing substances to form hydroxylated ions, facilitating further polycondensation reactions ； The amount of water can control the alkalinity of the medium, thereby promoting and regulating the rearrangement of various components in the system as well as the growth of certain zeolite seeds. Therefore, a certain amount of water must be present in the reaction mixture for synthesizing zeolites to ensure that the reaction proceeds in a direction favorable for a specific type of zeolite.