Abstract: As an important class of inorganic porous materials, silicaluminophosphate molecular sieves (SAPO) have been widely used in catalysis, adsorption, separation and environmental protection in recent years. The narrow porous channels of SAPO molecular sieves bring great resistance to mass transfer, which are unfavorable to the contact between reactant molecules and active sites in the pores. Reducing the grain size of SAPO molecular sieves can shorten the residence time of reactant molecules in the pores, thus improving the utilization of active centers. The research progress of small crystal SAPO molecular sieve synthesis methods in recent years was reviewed, including the mixed-template method, seed-assisted method, and so on. Furthermore, the advantages and disadvantages of these synthesis methods were elucidated. The mixed-template method was a simple and mature process for the synthesis of small crystal SAPO molecular sieves, and the future research should focus on how to reduce the use of organic templates. Other synthesis methods were mostly in the theoretical research stage, and the future research should focus not only on the optimization of the synthesis process, but also on the development of molecular sieve synthesis equipments.

Key words: silicaluminophosphate molecular sieves, small crystal, synthesis method, template