M. Bajus et Mh. Back, THE USE OF CARBON CATALYSTS AND OF NITROUS-OXIDE IN PROMOTING THE CONVERSION OF METHANE, Applied catalysis. A, General, 128(1), 1995, pp. 61-77
This paper reports on the coupling of methane to C-2 and higher hydroc
arbons over a carbon catalyst in the absence and presence of nitrous o
xide and a lithium-promoted carbon catalyst in the absence and presenc
e of nitrous oxide. The kinetics of the methane conversion were studie
d in a flow system over the temperature range 700-1100 degrees C. At 8
50 degrees C the conversion of methane was increased by a factor of ab
out 800 in the presence of the carbon catalyst. The selectivity to C-2
hydrocarbons was, however, low and the main products were hydrogen an
d carbon. The Li/carbon catalyst was similarly effective and led to a
better selectivity for C-2 hydrocarbons. Nitrous oxide had a strong pr
omoting effect on the homogeneous coupling of methane but a less notic
eable effect in the presence of the catalysts. Nitrous oxide improved
the selectivity to C-2 hydrocarbons. Under the conditions of the prese
nt experiments the carbon-lithium oxide catalyst is able to facilitate
the oxidative coupling of methane to give 36% conversion with selecti
vity to C-2 hydrocarbons over 70%.