abstract |
A multilayer supported oxidative coupling of methane (OCM) catalyst composition (alpha-Al2O3 support, first single oxide layer, one or more mixed oxide layers, optional second single oxide layer) characterized by formula AaZbEcDdOx/alpha-Al2O3; 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 alpha-Al2O3 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. |