Mixed oxide catalyst for the oxidative coupling of methane

A system for oxidative coupling of methane comprising:

• a source of methane;
• a source of oxygen;
• a catalytic material, wherein the catalytic material comprises a catalyst with the formula AaBbCcDdOx, and wherein:
• element A is selected from alkaline earth metals;
• elements B and C are selected from rare earth metals, and wherein B and C are different rare earth metals;
• the oxide of at least one of A, B, C, and D has basic properties;
• the oxide of at least one of A, B, C, and D has redox properties;
• a=1.0;
• b, c, and d are each in the range from about 0.01 to about 10;
• and x is a number selected to balance the oxidation state D;
• and
• elements A, B, C, and D are selected to create a synergistic effect whereby the catalytic material provides a methane conversion of greater than or equal to 15% and a C2+ selectivity of greater than or equal to 70%, and
• wherein the catalytic material produces ethane, ethylene, or combinations thereof;
• and a device for collecting or purifying the ethane, ethylene, or combinations thereof.

A method for the oxidative coupling of methane comprising:

• providing a source of methane;
• providing a source of oxygen;
• contacting the source of methane and the source of oxygen with a catalytic material, wherein the catalytic material comprises a catalyst with the formula AaBbCcDdOx, and wherein:
• element A is selected from alkaline earth metals;
• elements B and C are selected from rare earth metals, and wherein B and C are
• different rare earth metals;
• the oxide of at least one of A, B, C, and D has basic properties;
• the oxide of at least one of A, B, C, and D has redox properties;
• a=1.0;
• b, c, and d are each in the range from about 0.01 to about 10;
• and x is a number selected to balance the oxidation state of D;
• and
• elements A, B, C, and D are selected to create a synergistic effect whereby the catalytic material provides a methane conversion of greater than or equal to 15% and a C2+ selectivity of greater than or equal to 70%, and
• wherein the catalytic material produces ethane, ethylene, or combinations thereof after contact with the source of methane and the source of oxygen;
• and
• collecting or purifying the ethane, ethylene, or combinations thereof.