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 catalysts for methane dehydro-aromatization, measured by ~1H MAS NMR, was found to be about 1 when adjusting the acid sites by altering either the SiO_2/Al_2O_3 ratios or the Mo loading. This implies that a concerted interaction between the Mo species and the Bronsted acid sites probably features the bifunctionality of the Mo/HZSM-5 catalyst. On the other hand, it was found that the driving force for Mo species to move into The HSZM-5 zeolite channels and the interaction between the Mo species and the Bronsted acid sites are Closely and proportionably related with the amount of Bronsted acid sites per unit cell.