Preparation of catalyst and use for high yield conversion of methane to ethylene

A method of oxidative coupling of methane for the formation of heavier hydrocarbons, the method comprising the steps of:

• producing a perovskite catalyst, the catalyst produced by a process comprising:
• forming an aqueous slurry comprising an alkaline earth metal salt, a powdered metal salt and a powdered transition metal oxide, wherein the alkaline earth metal is selected from the group consisting of calcium (Ca), barium (Ba) and strontium (Sr) salts, wherein the metal salt is tin (Sn);
• wherein the transition metal oxide is titanium oxide;
• drying the slurry to form a powder;
• heating the powder at increasing temperatures at a predetermined profile;
• and
• calcining the heated powder to produce the perovskite catalyst,
• wherein the perovskite catalyst comprises a mixture including Ba+TiO2+R, wherein R is tin (Sn);
• and
• contacting a feed gas stream containing methane and oxygen in an oxidative coupling reactor under oxidative coupling conditions in the presence of the perovskite catalyst.