The role of the oxide catalyst in the methane coupling reaction is to activate the methane to form methyl radicals. These radicals are released into the gas phase, where they react further with molecular oxygen and other hydrocarbon intermediates to form the final product mix. The preferred catalysts efficiently form methyl radicals from methane without combusting the reaction products. The main impetus of this research work has been to try to find out what controls this activity. In examining the relationship between oxide structure and activity, the authors have concentrated on the simple oxide MgO. This oxide can be prepared by three different routes: burning magnesium ribbon in air, thermal decomposition of magnesium hydroxide, and thermal decomposition of magnesium basic carbonate