what molecular sieve？

Molecular sieve, often called zeolites or zeolite molecular sieves, are classically defined as "aluminosilicates with a pore (channel) framework structure that can be occupied by many large ions and water". According to the traditional definition, molecular sieves are solid adsorbents or catalysts with a uniform structure that can separate or selectively react molecules of different sizes. In a narrow sense, molecular sieves are crystalline silicates or aluminosilicates, which are connected by silicon-oxygen tetrahedra or aluminum-oxygen tetrahedra through oxygen bridges to form a system of channels and voids, thus having the characteristics of sieving molecules. Basically, it can be divided into several types of A, X, Y, M and ZSM, and researchers often attribute it to the solid acid category.