Silicoaluminophosphate (SAPO)molecular sieves, as one class of the most important inorganic crystalline materials, have attracted extensive attentions from both industrial and academic fields due to their uniform microporous structures, large surface area, tunable acidity and high thermal/hydrothermal stabilities. In particular, they are excellent heterogeneous solid acid catalysts with mild acidity and regular channel systems. Considerable efforts have been made to explore new SAPO molecular sieves encouraged by their huge application potentials.

Solvent also has a strong influence on the crystalline products. The polarity, solubility, vapor pressure and other characteristics of solvent can change the status of reactants and crystallization mechanism resulting in different crystalline phase. In recent years, the research group led by Prof. Tian Peng and Prof. Liu Zhongmin synthesized SAPO molecular sieves by using organic amines as solvents and OSDAs simultaneously. A lot of SAPO molecular sieves were synthesized efficiently, and some new OSDAs for directing SAPO-34 molecular sieve were found which may have significant effect on its acidity and MTO catalytic performance. The intense interactions between the organic amines and inorganic species as well as the strong basic environment of aminothermal condition promote the crystallization of SAPO molecular sieves. Meanwhile, the crystallization pathway may change due to the shortage of water. It is reasonable to expect some new SAPO phase under such an aminothermal system.

In this work, the research group reports the synthesis of SAPO molecular sieves by using alkanolamine as both a solvent and a template, with the assistance of quaternary amine co-template and fluoride mineralizing agent. Alkanolamine, possessing dual features of organic amine and alcohol, brings new opportunities for the discovery of SAPO molecular sieves. Two SAPO phases with –CLO (SAPO-DNL-1) and MEI (ECR-40F) topologies were synthesized.