镓改性 HZSM-5 催化低碳烷烃芳构化研究进展

Benzene, toluene and xylene (BTX), as important basic chemical raw materials, are mainly obtained from petroleum-based process, such as catalytic reforming and steam cracking. However, with the increasing consumption of petroleum resources, it becomes imperative to develop new BTX production technology. Some BTX production technologies reported so far include methanol to aromatics, syngas to aromatics, CO₂ hydrogenation to aromatics and aromatization of light alkanes. Among them, the aromatization of light alkanes has attracted widespread attention due to the sufficient raw materials and low-cost process. Among many aromatization catalysts, the gallium modified HZSM-5 catalysts exhibit excellent dehydrogenation-aromatization performance and are the research hotspot in this field. This paper mainly reviewed the research progress of gallium modified HZSM-5 catalysts in the aromatization of light alkanes from the aspects of the reaction mechanism, the regulation of catalyst properties, and the operating conditions. It was summarized that the state and distribution of Ga species can be controlled by the gallium introduction way, atmosphere pretreatment and calcination temperature. Regulating the acid properties and pore structure of HZSM-5 can improve the activity and stability of catalysts. The introduction of additives such as Pd, Ag, Ni, Pt and Cr can enhance the dehydrogenation activity and improve the aromatization ability. The synergistic effect between B acid sites and L acid sites (active Ga species) in gallium modified HZSM-5 catalysts is helpful to improve the light alkanes aromatization performance. Finally, this paper pointed out that the development of multi-functional synergistic gallium modified HZSM-5 catalysts in the processes of light alkane aromatization and CO₂ co-feeding is the key to increasing BTX production and reducing CO₂ emissions.