CATALYTIC CONVERSION OF METHANE TO BENZENE OVER MO ZSM-5/

Dehydroaromatization of methane to benzene occurs over a 2 wt% Mo/ZSM- 5 catalyst at 700 degrees C under non-oxidizing conditions. Following an initial induction period, during which CH4 reactant reduces the ori ginal Mo6+ ions in the zeolite to Mo2C and deposition of coke occurs, a benzene selectivity of similar to 70% at a CH4 conversion of 8-10% c ould be sustained for more than 16 h. X-ray photoelectron spectroscopy and X-ray powder diffraction measurements indicate that the reduced M o is highly dispersed in the channels of the zeolite. Initial activati on of CH4 reactant occurs on Mo2C sites, leading to the formation of C 2H4 as the primary product. The latter then undergoes subsequent oligo merization reactions on acidic sites of the zeolite to form aromatic p roducts.