THE USE OF CARBON CATALYSTS AND OF NITROUS-OXIDE IN PROMOTING THE CONVERSION OF METHANE

This paper reports on the coupling of methane to C-2 and higher hydrocarbons over a carbon catalyst in the absence and presence of nitrous oxide and a lithium-promoted carbon catalyst in the absence and presence of nitrous oxide. The kinetics of the methane conversion were studied in a flow system over the temperature range 700-1100 degrees C. At 850 degrees C the conversion of methane was increased by a factor of about 800 in the presence of the carbon catalyst. The selectivity to C-2 hydrocarbons was, however, low and the main products were hydrogen and carbon. The Li/carbon catalyst was similarly effective and led to a better selectivity for C-2 hydrocarbons. Nitrous oxide had a strong promoting effect on the homogeneous coupling of methane but a less noticeable effect in the presence of the catalysts. Nitrous oxide improved the selectivity to C-2 hydrocarbons. Under the conditions of the present experiments the carbon-lithium oxide catalyst is able to facilitate the oxidative coupling of methane to give 36% conversion with selectivity to C-2 hydrocarbons over 70%.