Identification Of The Coke Accumulation And Deactivation Sites Of Mo2C/HZSM-5 Catalyst In CH4 Dehydroaromatization

Abstract Identifying the preferentially coking sites of Mo 2 C/HZSM-5 catalyst in the CH 4 dehydroaromatization at non-oxidative conditions was attempted by employing a physically separable Mo 2 C/α-Al 2 O 3  + HZSM-5 mixture instead of Mo 2 C/HZSM-5 as catalyst. Photographic observation on the spent Mo 2 C/α-Al 2 O 3 and HZSM-5 components separated from the deactivated mixture and their thermogravimetric analysis clearly revealed that coke accumulation occurred predominantly on the HZSM-5. Then, the comparative activity tests with the physical blends of the deactivated Mo 2 C/α-Al 2 O 3  + HZSM-5 mixture sample with fresh Mo 2 C/α-Al 2 O 3 or HZSM-5 further confirmed that the coked HZSM-5 component in the deactivated mixture definitely deactivated while that un-coked Mo 2 C constituent remained highly active.