Study on Bifunctionality of Mo/HZSM-5 Catalysts for Methane Dehydro-Aromatization under Non-oxidative Condition

摘要

The optimum Mo/[H+] ratio per unit cell of the active precursors in Mo/HZSM-5 catalystsfor methane dehydro-aromatization, measured by 1H MAS NMR, was found to be about 1 when adjustingthe acid sites by altering either the SiO2/Al2O3 ratios or the Mo loading. This implies that a concertedinteraction between the Mo species and the Bronsted acid sites probably features the bifunctionality of theMo/HZSM-5 catalyst. On the other hand, it was found that the driving force for Mo species to move intothe HSZM-5 zeolite channels and the interaction between the Mo species and the Bronsted acid sites areclosely and proportionably related with the amount of Bronsted acid sites per unit cell.