Conversion of methane over ZSM-5 (MFI) and Y zeolites containing a transition metal

Abstract

Conversion of methane over ZSM-5 (MFI) and Y zeolites containing a transition metal under non-oxidative condition was investigated in this research with Mo. The catalysts were prepared by the impregnation method. It has been found that the appropriate reaction temperature, the percentage of Mo loading and GHSV over Mo/HZSM-5 catalyst were 700℃, 8% by weight and 2000 h⁻¹, respectively. The main hydrocarbon products from this reaction were C₂H₄, C₂H₆ and C₆H₆. The selectivity to benzene was 73% at 12.43% methane conversion. It was suggested that the formation of benzene possibly proceeded via ethylene intermediate. With the effect of space velocity of methane, the amount of ethylene and ethane was increased when the space velocity of methane was increased from 2000 h⁻¹ to 6000 h⁻¹. 8%Mo/HZSM-5 resulted in the relatively higher activity than 8%Mo/HY. Therefore, zeolites structure had a significant effect on the catalytic performance. Additionally, CO can be generated via reaction of methane with O-atoms HZSM-5 zeolite framework at high temperature (ca. 700℃).