One-step synthesis of hierarchical lamellar H-ZSM-5 zeolite and catalytic performance of methanol to olefin

In this paper, a hierarchical lamellar H-ZSM-5 zeolite (HLHZ) was successfully synthesized for methanol to olefin (MTO) by one-step crystallization, using urea instead of sodium hydroxide, and PEG2000 as soft-template. Urea was conducive to the formation of H-ZSM-5 zeolite directly after calcination to decomposed NH4+ into NH3 and remain H+ on the framework of ZSM-5 zeolite, thereby reducing the energy consumption caused by further ion exchange. The results showed that urea could guide the formation of b-axis-oriented lamellar H-ZSM-5 zeolite (LHZ) directly, and PEG2000 effectively guide the formation of HLHZ while reducing crystal particles size. Moreover, HLHZ exhibited longer catalytic lifetime and higher olefin selectivity. In conclusion, this work provided an energy-efficient and eco-friendly synthesis strategy, which conformed to the principles of green chemistry.