Methane Pyrolysis over Carbon Catalysts
S.D. Kushch1, V.Е. Muradyan1, P.V. Fursikov1, Eu.I.Knerelman1 V.L.Kuznetsov2 and Yu.V. Butenko2
1Institute of Problem of Chemical Physics Russian Academy of Sciences, 18 Institutsky prospect, Chernogolovka, Moscow Region, Russian Federation, 142432
2Boreskov Institute of Catalysis SB RAS, 5 Lavrentieva str., 630090 Novosibirsk, Russia
Methane pyrolysis at the temperature range of 550-1000° C in gas flow reactor with fixed bed of mixed catalysts based on carbon materials of various structure (fullerene cocoons, fullerene black, vacuum black, cathode deposit, onion-like carbon, glassy carbon, carbon fibers, mineral shungite and graphite) has been studied. Methane pyrolysis products, including stoichiometric amount of hydrogen are C3-C4 alkanes, C2-C4 alkenes, aromatics and pyrolytic carbon. Methane pyrolysis is carried out both on a catalytic surface and in a volume and contribution of the surface is determined by pyrolysis temperature. Materials with curved carbon surface show an activity in methane dehydrogenation at lower temperatures, than materials with planar basic structure elements. Materials with a small specific surface area favor methane aromatization at 950–1000° C with formation of mainly benzene, toluene and naphthalene. The primary activation of C–H bond in methane at temperatures of lower than 850° C, as well as the multiple dehydrogenation conversions resulting in the formation of pyrolytic carbon and its precursors (aromatics), are, probably, heterogeneous reactions.