Abstract: A multilayer supported oxidative coupling of methane (OCM) catalyst composition (support, first single oxide layer, one or more mixed oxide layers, optional second single oxide layer) characterized by formula AaZbEcDdOx/support; A is alkaline earth metal; Z is first rare earth element; E is second rare earth element; D is redox agent/third rare earth element; the first, second, third rare earth element are not the same; a=1.0; b=0.1-10.0; c=0.1-10.0; d=0-10.0; x balances oxidation states; first single oxide layer (Zb1Ox1, b1=0.1-10.0; x1 balances oxidation states) contacts support and one or more mixed oxide layers; one or more mixed oxide layers (Aa2Zb2Ec2Dd2Ox2, a2=1.0; b2=0.1-10.0; c2=0.1-10.0; d2=0-10.0; x2 balances oxidation states; AaZbEcDdOx and Aa2Zb2Ec2Dd2Ox2 are different) contacts first single oxide layer and optionally second single oxide layer, and second single oxide layer (AO), when present, contacts one or more mixed oxide layers and optionally first single oxide layer.

Abstract: A multilayer supported oxidative coupling of methane (OCM) catalyst composition (support, first single oxide layer, one or more mixed oxide layers, optional second single oxide layer) characterized by formula AaZbEcDdOx/support; A is alkaline earth metal; Z is first rare earth element; E is second rare earth element; D is redox agent/third rare earth element; the first, second, third rare earth element are not the same; a=1.0; b=0.1-10.0; c=0.1-10.0; d=0-10.0; x balances oxidation states; first single oxide layer (Zb1Ox1, b1=0.1-10.0; x1 balances oxidation states) contacts support and one or more mixed oxide layers; one or more mixed oxide layers (Aa2Zb2Ec2Dd2Ox2, a2=1.0; b2=0.1-10.0; c2=0.1-10.0; d2=0-10.0; x2 balances oxidation states; AaZbEcDdOx and Aa2Zb2Ec2Dd2Ox2 are different) contacts first single oxide layer and optionally second single oxide layer, and second single oxide layer (AO), when present, contacts one or more mixed oxide layers and optionally first single oxide layer.

Abstract: An OCM catalyst composition characterized by general formula AaLabEcDdOx; wherein A is an alkaline earth metal; wherein E is a first rare earth element; wherein D is a redox agent or a second rare earth element; wherein the first rare earth element and second rare earth element are different; wherein a is 1.0; wherein b is 0.01-10.0; wherein c is 0-10.0; wherein d is 0-10.0; and wherein x balances the oxidation states. The alkaline earth metal is selected from the group consisting of Mg, Ca, Sr, Ba, and combinations thereof. The first rare earth element and the second rare earth element can each independently be selected from the group consisting of Sc, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Y, Tb, Dy, Ho, Er, Tm, Yb, Lu, and combinations thereof. The redox agent is selected from the group consisting of Mn, W, Bi, Sb, Sn, Ce, Pr, and combinations thereof.

Abstract: A supported oxidative coupling of methane (OCM) catalyst comprising a support and an OCM catalytic composition characterized by the general formula AaZbEcDdOx; wherein A is an alkaline earth metal; wherein Z is a first rare earth element; wherein E is a second rare earth element; wherein D is a redox agent or a third rare earth element; wherein the first rare earth element, the second rare earth element, and the third rare earth element, when present, are not the same; wherein a is 1.0; wherein b is from about 0.1 to about 10.0; wherein c is from about 0.1 to about 10.0; wherein d is from about 0 to about 10.0; and wherein x balances the oxidation states.

Abstract: An OCM nanoplate catalyst comprising ?25 wt. % nanoplates; wherein a nanoplate is a three-dimensional object defined in accordance with ISO/TS 80004-2:2015; wherein a nanoplate is characterized by a first external dimension (thickness (t)?100 nm), a second external dimension (length (l)>t), and a third external dimension (width (w)>t); wherein l and w can be the same or different; and wherein l?5 t, w?5 t, or l?5 t and w?5 t; and wherein the OCM nanoplate catalyst has general formula AaZbEcDdOx; wherein A=alkaline earth metal; Z=first rare earth element; E=second rare earth element; D=redox agent/third rare earth element; wherein the first, second, and third rare earth element are not the same; wherein a=1.0; wherein b=1.0 to 3.0; wherein c=0 to 1.5; wherein d=0 to 1.5; wherein (b>(c+d)); and wherein x balances the oxidation states.

Abstract: An OCM nanoplate catalyst comprising >25 wt. % nanoplates; wherein a nanoplate is a three-dimensional object defined in accordance with ISO/TS 80004-2:2015; wherein a nanoplate is characterized by a first external dimension (thickness (t)>100 nm), a second external dimension (length (l)?t), and a third external dimension (width (w)?t); wherein l and w can be the same or different; and wherein l?5 t, w?5 t, or l?5 t and w?5 t; and wherein the OCM nanoplate catalyst has general formula AaZbEcDdOx; wherein A=alkaline earth metal; Z=first rare earth element; E=second rare earth element; D=redox agent/third rare earth element; wherein the first, second, and third rare earth element are not the same; wherein a=1.0; wherein b=1.0 to 3.0; wherein c=0 to 1.5; wherein d=0 to 1.5; wherein (b>(c+d)); and wherein x balances the oxidation states.

Abstract: A supported oxidative coupling of methane (OCM) catalyst comprising a support and an OCM catalytic composition characterized by the general formula AaZbEcDdOx; wherein A is an alkaline earth metal; wherein Z is a first rare earth element; wherein E is a second rare earth element; wherein D is a redox agent or a third rare earth element; wherein the first rare earth element, the second rare earth element, and the third rare earth element, when present, are not the same; wherein a is 1.0; wherein b is from about 0.1 to about 10.0; wherein c is from about 0.1 to about 10.0; wherein d is from about 0 to about 10.0; and wherein x balances the oxidation states.

Abstract: A catalytic material for oxidative coupling of methane includes: a catalyst with the formula AaBbCcOx, wherein: A is selected from alkaline earth metals; B and C are selected from rare earth metals, and wherein B and C are different rare earth metals; and the oxide of at least A, B, and C has basic, redox, or both basic and redox properties, and wherein the elements A, B, and C are selected to create a synergistic effect whereby the catalytic material provides an oxygen conversion of greater than or equal to 50% and a C2+ selectivity of greater than or equal to 70%, and wherein the catalyst provides the oxygen conversion and selectivity at a temperature of 797° F. (425° C.) or greater. The catalyst can be used in an oxidative coupling of methane reactor at lower feed temperatures compared to other catalysts.

Abstract: An OCM catalyst composition characterized by general formula AaLabEcDdOx; wherein A is an alkaline earth metal; wherein E is a first rare earth element; wherein D is a redox agent or a second rare earth element; wherein the first rare earth element and second rare earth element are different; wherein a is 1.0; wherein b is 0.01-10.0; wherein c is 0-10.0; wherein d is 0-10.0; and wherein x balances the oxidation states. The alkaline earth metal is selected from the group consisting of Mg, Ca, Sr, Ba, and combinations thereof. The first rare earth element and the second rare earth element can each independently be selected from the group consisting of Sc, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Y, Tb, Dy, Ho, Er, Tm, Yb, Lu, and combinations thereof. The redox agent is selected from the group consisting of Mn, W, Bi, Sb, Sn, Ce, Pr, and combinations thereof.