The invention relates to a composition containing a catalyst suitable for producing ethylene and other C.sub.2+ hydrocarbons at high selectivity while improving both methane conversion and product yield. Particularly, the catalyst contains mixed metal oxides having at least one alkali earth metal and at least one rare earth metal along with an alkali metal promoter in the form of an alkali metal or in the form of an alkali metal tungstate. The invention further provides a method for preparing such a composition, using a calcination process to calcine the alkali metal promoters together with mixed metal oxides. Additionally, the invention further describes a process for producing C.sub.2+ hydrocarbons, using such a composition.

An OCM catalyst composition characterized by general formula A.sub.aLa.sub.bE.sub.cD.sub.dO.sub.x; 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.

An OCM catalyst composition characterized by general formula A.sub.aLa.sub.bE.sub.cD.sub.dO.sub.x; 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.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the inlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first palladium component; a second catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the second catalytic region comprises a second palladium component; a third catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the third catalytic region comprises a third rhodium component; and wherein the third catalytic region overlies the second catalytic region.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the inlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first palladium component; a second catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the second catalytic region comprises a second palladium component; a third catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the third catalytic region comprises a third rhodium component; and wherein the third catalytic region overlies the second catalytic region.

The invention relates to a composition containing a catalyst suitable for producing ethylene and other C.sub.2+ hydrocarbons at high selectivity while improving both methane conversion and product yield. Particularly, the catalyst contains mixed metal oxides having at least one alkali earth metal and at least one rare earth metal along with an alkali metal promoter in the form of an alkali metal or in the form of an alkali metal tungstate. The invention further provides a method for preparing such a composition, using a calcination process to calcine the alkali metal promoters together with mixed metal oxides. Additionally, the invention further describes a process for producing C.sub.2+ hydrocarbons, using such a composition.

The invention relates to a composition containing a catalyst suitable for producing ethylene and other C.sub.2+ hydrocarbons at high selectivity while improving both methane conversion and product yield. Particularly, the catalyst contains mixed metal oxides having at least one alkali earth metal and at least one rare earth metal along with an alkali metal promoter in the form of an alkali metal or in the form of an alkali metal tungstate. The invention further provides a method for preparing such a composition, using a calcination process to calcine the alkali metal promoters together with mixed metal oxides. Additionally, the invention further describes a process for producing C.sub.2+ hydrocarbons, using such a composition.

A supported oxidative coupling of methane (OCM) catalyst comprising a support and an OCM catalytic composition characterized by the general formula A.sub.aZ.sub.bE.sub.cD.sub.dO.sub.x; 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.

A supported oxidative coupling of methane (OCM) catalyst comprising a support and an OCM catalytic composition characterized by the general formula A.sub.aZ.sub.bE.sub.cD.sub.dO.sub.x; 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.

The presently claimed invention relates an automotive catalyst system which can be used to selectively reduce carbon monoxide. The system comprises a first close coupled three-way conversion catalytic article in fluid communication with an engine exhaust outlet, a catalytic article located downstream of and in fluid communication with the first close coupled three-way conversion catalytic article, a tail-pipe catalytic article arranged downstream in fluid communication and 1.0 to 10 feet away from the catalytic article at a position selected from before or behind a resonator, before or after a muffler, between the resonator and the muffler, inside the muffler, inside the resonator, and at a tail pipe end.