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Methane and ethane activation without adding oxygen: promotional effect of W in Mo-W/HZSM-5

Research paper by She-Tin Wong, Yide Xu, Linsheng Wang, Shetian Liu, Guangjin Li, Maosong Xie, Xiexian Guo

Indexed on: 01 Mar '96Published on: 01 Mar '96Published in: Catalysis Letters



Abstract

The conversions of methane and ethane over Mo/HZSM-5 and W/HZSM-5 catalysts are compared. A reaction model for hydrocarbon formation over Mo/HZSM-5 catalysts is proposed, which involves heterolytic splitting of methane and a molybdenum-carbene intermediate. Ethene is shown to be the initial product of methane conversion, and it undergoes further reaction to form aromatics in a solid acid environment. The promotional effect of addition of tungsten in the Mo-W/HZSM-5 catalyst in methane conversion reaction suggests the formation of Mo-W mixed oxide. The product selectivity patterns of Mo/HZSM-5 and W/HZSM-5 catalysts in ethane conversion reaction are consistent with a dual-path model involving dehydrogenation and cracking (or hydrogenolysis) of ethane. The rates of both these reactions over Mo/HZSM-5 are higher than over W/HZSM-5.