Aromatization of methane over supported and unsupported Mo-based catalysts

Journal Article · Wed Jan 15 04:00:00 EST 1997 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1997.1478· OSTI ID:476800

Solymosi, F; Cserenyi, J; Szoeke, A ^[1]

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1. Academy of Sciences, Szeged (Hungary); and others

The interaction of methane with unsupported and supported molybdenum compounds (Mo, MoO{sub 2}, MoO{sub 3}, Mo{sub 2}C, and MoC{sub (1-x)}) has been investigated at 973 K. ZSM-5 was used as a support. Reaction products were analyzed using gas chromatography. Changes in the composition of catalyst samples were followed by X-ray photoelectron spectroscopy. Molybdenum metal and oxides interacted strongly with methane at 973 K to give H{sub 2} (MO) and H{sub 2}O and CO{sub 2} (oxides), but only a trace amount of ethane. When these compounds were contacted with ZSM-5, the reaction pathway of methane initially was the same. Afterward, however, a dramatic change occurred in the product distribution: the formation of ethane, ethylene, and benzene came into prominence. This was particularly the case when these compounds were highly dispersed on ZSM-5. The selectivity to benzene was 80-85%. XPS analysis of Mo-containing catalysts demonstrated the formation of MO carbides during the catalytic reaction. Unsupported MO carbides behaved like metallic MO; the dominant process was the decomposition of methane to hydrogen and carbon. The deposition of Mo{sub 2}C on ZSM-5 in a well-dispersed state, however, produced a very active and selective catalyst for the conversion of methane into benzene. The results suggest that Mo{sub 2}C is the active surface species in the Mo-containing catalysts, which converts methane into ethylene, the primary compound for the production of benzene on the zeolite surface. 28 refs., 9 figs., 2 tabs.

• OSTI ID: 476800
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 2 Vol. 165; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

10 SYNTHETIC FUELS
40 CHEMISTRY
AROMATIZATION
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
METHANE
MOLYBDENUM
MOLYBDENUM CARBIDES
MOLYBDENUM OXIDES
PHOTOELECTRON SPECTROSCOPY
ZEOLITES