A new way to enhance the coke-resistance of Mo/HZSM-5 catalyst for methane dehydroaromatization

A thermal dealumination method was applied to modify HZSM-5 zeolites, and the Mo/HZSM-5 catalyst pre-dealuminated in N2 stream exhibited rather high catalytic activity and stability in the methane dehydroaromatization reaction (MDA). 29Si NMR, FT-IR and TPO measurements show that the thermal treatment of the HZSM-5 in inert atmosphere induced partial removal of tetrahedral coordinated Al from the zeolite lattices leading to elimination of the original excess strong Brönsted acid sites (known as responsible for the coke formation), and thus significantly promoted the coke-resistance of the Mo/HZSM-5 catalyst.