Binary solids consisting of an alkali metal, sodium, and an alkaline earth, strontium, supported on silica have been examined for their catalytic activity, selectivity, and stability in the oxidative coupling of methane. The catalysts prepared by co-impregnation, sequential and reverse sequential methods have been compared for various loadings and the effect of tetrachloromethane (TCM) introduced into the feedstream has been examined. With all preparations the introduction of TCM into the feedstream increased both the selectivities to Ca hydrocarbons and the conversions of methane. However, the greatest enhancement occurred with the 1.5% Na, 10% Sr/SiO2 sequentially prepared catalyst for which the highest selectivity was 84% at a conversion of 20%. Catalysts containing 2.5-5.0% Na and 10% Sr prepared by sequential impregnation also showed, in the presence of TCM, the highest stabilities under reaction conditions with conversions and selectivities remaining constant for up to 80 h on-stream at 800 degrees C reaction temperature. The enhanced stabilities of the catalyst are attributed to the formation of one or more new phases from the strong interaction between the support and the supported materials.