Study Of Methane Anaerobic Aromatization Catalyst Hzsm-5 Vector

Methane non-oxidative aromatization is very significant to utilization of resources and science of catalysis. Mo/HZSM-5 catalyst has a very good catalytic performance in methane non-oxidative aromatization. HZSM-5 has particular pore structure and acidity, and it is proved to be a very good support. The effect of support properties on catalytic performance of Mo/HZSM-5 in methane non-oxidative aromatization is studied in this paper. Catalytic performance of 6%Mo/HZSM-5 catalysts with different SiO2/Al2O3 ratios is investigated. It is found that, the lower SiO2/Al2O3 ratio is, the stronger the acidity of HZSM-5 is, and the higher the conversion rate of methane is. In addition, catalytic performance of 6% Mo/HZSM-5 with the same SiO2/Al2O3 ratio but different crystallinity is tested. The results show that crystallinity does not significantly affect the catalytic performance. Therefore, the catalytic performance of Mo/HZSM-5 for methane non-oxidative aromatization doesn't mainly depend on crystallinity, but acidity of support. Catalytic performance of 6% Mo/HZSM-5 with different crystal size is investigated. It is proved that , there is a close correlation between the activity of reaction and the acidity of HZSM-5. Catalytic performance of 6% Mo/HZSM-5 with the close acidity of HZSM-5 but different crystal sizes is also tested. It is found that, the smaller the crystal size is, the higher the activity of reaction is. Based on the above, it is suggested that HZSM-5 is not only the support of catalyst, but also plays an acid catalytic role. The influence of nanosizd HZSM-5 and microsized HZSM-5 zeolites on catalytic performance of Mo/HZSM-5 in methane non-oxidative aromatization is studied. Nanosize HZSM-5 loaded with Mo has much better catalytic performance than microsize HZSM-5 loaded with Mo. It is found that, nanosize HZSM-5 is nano-particla agglomeration, and microsized HZSM-5 is a kind of twins crystals. Catalytic performance of Mo/HZSM-5 prepared by high-temperature hydrothermal method is also studied. No activity of the reaction results from the extraction of framework aluminum and the decrease of its reductive ability.