Non-oxidative dehydroaromatization of methane over Ga-promoted Mo/HZSM-5-based catalysts

The catalytic performance of Mo-based catalyst supported on HZSM-5 has been studied in the absence of oxygen for methane dehydroaromatization in a fixed-bed continuous flow quarts reactor. The results showed that addition of small amounts of gallium to Mo-H2SO4/HZSM-5 catalyst further improved the catalytic performance, and yields of C-2-C-11 hydrocarbons increased from 7.84 to 8.96%. TPR proved that the addition of gallium was advantageous for the reduction of MoO3 on HZSM-5 zeolite. Meanwhile, the amount of coke formation on Ga-Mo/HZSM-5 catalyst decreased gradually with increasing gallium contents. TPO results suggested that the type of coke, such as active carbon and inert carbon, deposited on Ga-Mo/HZSM-5 catalyst depends considerably on time-on-stream. The more inert carbon war formed on the surface of catalysts with increasing time-on-stream. (C) 2001 Elsevier Science B.V. All rights reserved.