Synthesis of hierarchical porous zeolite and its performance in n-heptane cracking

A series of hierarchical porous zeolites (ZSM-5–ZRP-1) was synthesized by adding different contents of ZRP-1 to the procedure of hydrothermal synthesis of ZSM-5. The prepared samples were characterized by using N2 adsorption–desorption, XRD, SEM, TEM, NH3-TPD, Py-FTIR and investigated in cracking of n-heptane. The results indicate that physicochemical properties and catalytic performances of ZSM-5–ZRP-1 samples are quite different from those of HZSM-5 or ZRP-1. ZSM-5–ZRP-1 samples have a lot of mesopores and suitable amount of B + L acid sites as well as higher L/B ratio compared with HZSM-5 or ZRP-1, and also show medium acid amount and strength. These lead to a higher selectivity of olefins (ethylene plus propylene) obtained on it.

Figure optionsDownload as PowerPoint slideHighlights
► Hierarchical zeolites (ZSM-5-ZRP-1) were synthesized by hydrothermal method.
► ZSM-5-ZRP-1 catalysts possess unique physicochemical properties.
► The enhanced activity of ZSM-5-ZRP-1 is related to its physicochemical properties.