Nonoxidative conversion of methane to aromatics over modified zeolite catalysts by transitional metals

The activity of different transitional metals over modified HZSM5 catalysts for methane conversion to aromatics was compared. The first group of catalysts was Moimpregnated HZSM5 zeolites with 1, 3 and 6 wt% of Mo. The second group was M(3 wt%) impregnated HZSM5 (M: Ag, Cd, Cr, Mo, Zn and Mn). The catalytic activity of the first group was investigated at 600, 700 and 800 °C and gas hourly space velocity (GHSV) of 1500, 2250, 3600 [ml.g1.h1]. Likewise, the second group of catalysts was examined at 700°C and GHSV of 2250 [ml.g1.h1]. The catalyst samples were appropriately characterized by XRD, BET and SEM techniques. The effect of loaded transitional metals on the methane conversion was sorted on the basis of benzene yield as following: 3%wt Mo gt; 3%wt Zn gt; 3%wt Mn gt; 3%wt Ag gt; 3%wt Cd gt; 3%wt Cr. The highest methane conversion was 11.13% obtained over the Mo(3 wt%)impregnated HZSM5 catalyst.