Benzene, toluene, and xylene production by direct dehydroaromatization of methane over WO_y/HZSM-5 catalysts

Tungsten oxide catalysts supported on HZSM-5 (XWO_y/HZSM-5) were prepared with a variation of tungsten oxide loading (X = 4, 6, 8, 10, and 12 wt%) for use in the production of BTX (Benzene, Toluene, and Xylene) through methane dehydroaromatization. The effect of tungsten oxide loading on the acid properties and catalytic activities was investigated. It was found that strong acidity of XWO_y/HZSM-5 catalysts showed a volcano-shaped trend with respect to tungsten oxide loading and 8WO_y/HZSM-5 catalyst exhibited the highest strong acidity. In the methane dehydroaromatization, acid property of XWO_y/HZSM-5 catalysts was closely related to BTX yield. Initial BTX yield increased with increasing strong acidity of the catalysts. Among the catalysts tested, 8WO_y/HZSM-5 catalyst with the highest strong acidity showed the best catalytic performance in terms of initial BTX yield. It is concluded that an optimal tungsten oxide loading of XWO_y/HZSM-5 catalysts was required for maximum BTX production in the methane dehydroaromatization.