Hierarchical Porous ZSM-5 Zeolite Synthesized by in situ Zeolitization and Its Coke Deposition Resistance in Aromatization Reaction

Hierarchical ZSM-5 zeolites with micro-, meso- and macroporosity were prepared from diatomite zeolitization through a vapor-phase transport process on solid surfaces. The aromatization performance of the catalysts was investigated on a fixed bed reactor by using FCC gasoline as feedstock. The crystal phase, morphology, pore structures, acidity and coke depositions of the hierarchical ZSM-5 zeolites were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption/desorption, Fourier transform infrared (FT-IR) and thermogravimetry-mass spectrogram (TG-MS), respectively. The results show that the prepared hierarchical ZSM-5 zeolite possesses excellent porosity and high crystallinity, displaying an improved aromatization performance and carbon deposition resistance due to its meso- and macroporous structures.