Abstract: The durability of methane dehydroaromatization (MDA) has been improved by its combination with methane steam reforming (MSR). The methane conversion in the combined MSR/MDA system decreases very slowly from 11.5% at 12.5 h to 6.5% at 60 h, whereas it decreases rapidly from 14.5% at 0.5 h to 3.5% at 15 h for the MDA reaction alone. CO and H₂ produced in-situ through the MSR reaction may reduce the amount of CH_x species during the reaction, which in turn reduces the formation of coke deposited on the catalyst, prolonging the durability of the MDA reaction. High content of H₂ from the MSR process plays a major role in suppressing coke accumulation on the catalyst, especially the coke associated with the Brönsted acidic sites that are mainly responsible for the deactivation.

Key words: methane dehydroaromatization, methane stream reforming, reaction coupling, molybdenum, MCM-49, coke deposition