Synthesis of hierarchical SAPO-۳۴ crystals with different preparationprocedures for the conversion of methanol to olefins

A series of SAPO-۳۴ molecular sieves with hierarchical porosity were prepared via fourdifferent preparation procedures with similar composition and hydrothermal conditions. Thecatalytic performance of these catalysts for methanol to light olefins reaction was investigated.The results indicated that the order of adding components in the synthesis gel has an effect on theselectivity and lifetime of the catalyst. The samples have a high proportion of framework Si (Si/(Si+ Al + P) between ۰.۴۹ to ۰.۶۲) and framework charge density (۰.۲۱<(Al–P) /(Si + Al + P) <۰.۳۸).The results proved that the prepared samples with a high degree of crystallinity ,high specificsurface area and more number of strong acid sites illustrated the high selectivity to light olefinsin the reaction of methanol to olefin. The recently results indicated the order of increasing theingredients affected the composition and crystalline phase of the product and the XRD resultsconfirmed the presence of SAPO-۵۶ phase next to the main SAPO-۳۴ phase

کلیدواژه ها:

SAPO-۳۴ ، different preparation procedures ، methanol to olefins