The catalytic low temperature oxydehydrogenation of methane. Temperature dependence,carbon balance and effects of catalyst composition

In an earlier publication 1] it has been claimed that oxidative coupling of methane to higher hydrocarbons had been obtained with close to 100% selectivity at 600 ° C and atmospheric pressure in the presence of steam over a CaNiK oxide catalyst. These results have been confirmed in longer runs. Artifacts, such as carbonate formation on the catalyst, have been excluded. The reaction is slightly exothermic. An Arrhenius plot shows that methane oxidation to CO₂ predominates at temperatures above 600 ° C and oxidative methane coupling at lower temperatures. The importance of exact catalyst composition is demonstrated.