Selective oxidation of methane to ethane and ethylene over various oxide catalysts

Preliminary results are reported for the oxidative coupling of methane to give ethane/ethylene mixtures over a series of different catalyst formulations; the temperature range studied is 650-850°C. A comparison is made of the behaviour of lead/alumina and lithium/magnesia materials. It is found that the former samples give ethane and ethylene plus a predominance of CO₂ whereas the latter give ethane and ethylene plus a mixture of CO, CO₂ and H₂; at higher temperatures, the lead materials give also H₂ and CO. The lithium-containing materials are much more stable than the lead-containing ones; the latter lose lead, probably by volatilisation of the metal. A number of other oxide materials have also been examined and have been found to be less effective, having lower activities and selectivities than the lead- and lithium-containing systems.