Influence of ZSM-5 porosity and binder introduction on the coke formation in the cracking of 1,3,5-triisopropylbenzene

Abstract

Hierarchical ZSM-5 catalysts with different pore sizes from micropore to macropore and their corresponding ZSM-5-based extrudates using SiO2 binders have been successfully prepared. The series of catalysts were used for exploring the influence of pore size as well as the addition of non-acidic SiO2 binders on the catalytic performance and coke formation in the cracking of 1,3,5-triisopropylbenzene (TIPB). It is demonstrated that the TIPB conversion and stability of catalysts improve with increasing the pore sizes of ZSM-5 catalysts. The hierarchical ZSM-5 catalyst including a macropore diameter of about 60 nm exhibited the highest TIPB conversion (98.6 %) and selectivities to propylene (34.2 %) and benzene (60.8 %) with the least amount of carbonaceous compounds, compared to the microporous and mesoporous ZSM-5 catalysts. Also, the addition of non-acidic SiO2 binders has a positive effect on limiting the deactivation of ZSM-5-based extrudates during the cracking of TIPB. Less poly-aromatic species are formed for the catalyst extrudates with SiO2 binders.