Facile synthesis of ZSM-5 nanosheet arrays by preferential growth over MFI zeolite [100] face for methanol conversion

Abstract In pertrochemical and biomass processes, HZSM-5 crystals with short straight channels are always preferred for easier diffusion reason and less coke formation. In this study, ZSM-5 nanosheets arrays with 50 nm straight channels are synthesized through their preferential growth over [100] faces of parent HZSM-5. The composite HZSM-5 is characterized by XRD, SEM, TEM, XPS, N 2 absorption and NH 3 -TPD and its anit-coke capability was evaluated with methanol conversion as a probe reaction. The short straight channels of HZSM-5 nanosheets facilitate the diffusion of molecules and showed extended lifetime than the corresponding parent HZSM-5. It is suggested that the [100] face of parent HZSM-5 crystal is more vulnerable than the [010] face, and produced much more defects in the alkaline recrystallization environment, and thus enabled the preferential growth of nanosheets. The mechanisms of nanosheets formation can be applied to the synthesis of ZSM-5 with shorter straight channels.