VPI-5分子筛热相变转化成AlPO_4-8的研究

Phase Transformation of Molecular Sieve VPI-5 into AlPO4-8 and the Relationship Between Both Frameworks

VPI-5是具有十八元环超大孔道的磷酸铝分子筛,在加热过程中,随着孔道中的水分子的脱除,其骨架结构转化成具有十四元环孔道的AlPO_4-8分子筛。采用XRD及骨架结构模型计算等方法研究了这一相变过程,并对相变机理进行了探讨。

The aluminophosphate molecular sieve VPI-5 has been received much attention as a new structure containing super-large open pores with 18 tetrahedral atoms. During the propcess of dehydration and desorption of water molecules in the channeles, the framework structure can be converted into AlPO4-8, which contains 14-membered ring open pores. The process of phase transformation was studied and the mechanism about the transformation is discussed.