Synthesis of nanocrystalline aggregate ZSM-5 zeolite with novel organosiloxane and the catalytic for C8 aromatics isomerization

This study aimed to synthesize a novel mesoporous template agent, KHBA, using 3-glycidoxypropyltrimethoxysilane (KH-560) and butylamine as raw materials, and to explore its application in the synthesis of ZSM-5 zeolites with nanocrystal aggregates. The physical and chemical properties of the synthesized ZSM-5 zeolites were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG), and low-temperature N 2 adsorption–desorption The results showed that the introduction of KHBA effectively inhibited excessive crystal growth and promoted the formation of nanocrystal aggregates with a mesoporous structure. In the synthesis system with a KHBA-to-Al 2 O 3 molar ratio ranging from 1.6 to 4.8, the external surface area and mesoporous volume of the samples increased with increasing KHBA content. The sample synthesized with a KHBA-to-Al 2 O 3 molar ratio of 4.8 exhibited the highest external surface area (250.43 m 2 /g) and mesoporous volume (0.24 cm 3 /g). In the catalytic performance test for C8 aromatic hydrocarbon isomerization, the catalyst prepared with a KHBA-to-Al 2 O 3 molar ratio of 4.8 demonstrated the best performance, with isomerization activity of 23.79%, ethylbenzene conversion of 88.94%, and xylene loss of 3.42%. These findings highlight the potential of KHBA as an effective template agent for the synthesis of high-performance ZSM-5 zeolites in catalytic applications.