مشخصات پژوهش

In this study, we synthesized zeolite catalysts by combination of multiple templates through hydrothermal method. TPABr, as a micropore template, nonionic copoly mer F127, and cationic surfactant CTAB as co-mesoporogens were utilized. We used the RSM method to design different template compositions. Twenty identified catalysts were synthesized, characterized, and evaluated for their catalytic perfor mance in MTP process. An R2 value of 0.9966 for the established quadratic model by using response surface methodology indicated a negligible lack of fit. According to the model, all three variables and their interactions affected selectivity of pro pylene. Characterizations results confirmed the changes in the efficiency of hier archical zeolites in practice and modeling. It was shown that the amounts of SDA and mesoporogens in catalyst composition were effective on intensity of diffraction peaks, orientation, morphology, functional groups, acidity, surface area, and size of pores. Moreover, performance of catalyst samples showed that presence of both mesoporogens (CTAB and F127) along with TPABr in catalyst composition led to a more efficient process. Average value of propylene selectivity for HZC (catalyst with central point composition) and HZO (optimum catalyst obtained by modeling) were 58 and 58.8, respectively. The outcomes of the present work suggested that catalysts with the composition of templates in the vicinity of the central point had the highest surface area, high mesopore volume, proper acidity promoting alkyla tion–dealkylation reactions, high stability, and highest selectivity to propylene.