A composite oxide including a metal element represented by the composition of general formula:

A.sub.nX.sub.y,

represents an element selected from the group consisting of Sc, Y, and a trivalent lanthanoid; X represents an element selected from the group consisting of Ca, Sr, and Ba; n is 0<n<1; y is 0<y<1; and n+y=1. Also, a metal-supported material in which cobalt particles are supported on the composite oxide.

A composite oxide including a metal element represented by the composition of general formula:

A.sub.nX.sub.y,

represents an element selected from the group consisting of Sc, Y, and a trivalent lanthanoid; X represents an element selected from the group consisting of Ca, Sr, and Ba; n is 0<n<1; y is 0<y<1; and n+y=1. Also, a metal-supported material in which cobalt particles are supported on the composite oxide.

A system for oxidative conversion of a mixed hydrocarbon feed stream to a product stream containing at least one olefin is provided. The system includes a plurality of reactors each capable of oxidatively dehydrogenating at least a portion of a hydrocarbon in the mixed hydrocarbon feed, and each reactor able to operate at different set of reaction conditions from other reactors in the plurality of reactors. All of the reactors use the same oxygen transfer agent to produce at least one olefin. In some embodiments, at least one reactor is optimized to oxidatively couple methane to produce ethylene, while other reactors are optimized to oxidatively dehydrogenate ethane to ethylene or to oxidatively dehydrogenate propane to ethylene and/or propylene. All of the reactors feed into a single regeneration unit for the oxygen transfer agent. A method of oxidatively converting the mixed hydrocarbon feed to an olefin is also provided.

A system for oxidative conversion of a mixed hydrocarbon feed stream to a product stream containing at least one olefin is provided. The system includes a plurality of reactors each capable of oxidatively dehydrogenating at least a portion of a hydrocarbon in the mixed hydrocarbon feed, and each reactor able to operate at different set of reaction conditions from other reactors in the plurality of reactors. All of the reactors use the same oxygen transfer agent to produce at least one olefin. In some embodiments, at least one reactor is optimized to oxidatively couple methane to produce ethylene, while other reactors are optimized to oxidatively dehydrogenate ethane to ethylene or to oxidatively dehydrogenate propane to ethylene and/or propylene. All of the reactors feed into a single regeneration unit for the oxygen transfer agent. A method of oxidatively converting the mixed hydrocarbon feed to an olefin is also provided.

A composition for catalysis of a Haber-Bosch process comprises an anion vacant lattice and a Haber-Bosch catalyst (e.g. Fe Ru). Suitable anion vacant lattices include oxynitrides and oxides, which may be doped or undoped, including Ce.sub.aM.sub.bO.sub.2-XN.sub.Y (Formula III) M is one or more elements with a valence lower than +4. “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1 (approximately). X is greater than 0 and less than 2. Y is greater than zero and less than or equal to X. A process employing the composition produces ammonia.

A composition for catalysis of a Haber-Bosch process comprises an anion vacant lattice and a Haber-Bosch catalyst (e.g. Fe Ru). Suitable anion vacant lattices include oxynitrides and oxides, which may be doped or undoped, including Ce.sub.aM.sub.bO.sub.2-XN.sub.Y (Formula III) M is one or more elements with a valence lower than +4. “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1 (approximately). X is greater than 0 and less than 2. Y is greater than zero and less than or equal to X. A process employing the composition produces ammonia.

An exhaust gas purifier is disposed in an exhaust gas passage of an engine, and includes: a DPF for capturing PM contained in exhaust gas; an SCR catalyst provided downstream of the DPF in a direction of flow of the exhaust gas, and for reducing NO.sub.x contained in the exhaust gas for purification in the presence of NH.sub.3; an injection unit provided between the DPF and the SCR catalyst, and for supplying urea to the SCR catalyst so as to supply NH.sub.3 to the SCR catalyst; and an AMOX provided downstream of the SCR catalyst in the direction of flow of the exhaust gas, and for removing NH.sub.3 having passed through the SCR catalyst. The DPF does not contain Pt or Pd, and contains Rh. The AMOX contains Pt.

An exhaust gas purifier is disposed in an exhaust gas passage of an engine, and includes: a DPF for capturing PM contained in exhaust gas; an SCR catalyst provided downstream of the DPF in a direction of flow of the exhaust gas, and for reducing NO.sub.x contained in the exhaust gas for purification in the presence of NH.sub.3; an injection unit provided between the DPF and the SCR catalyst, and for supplying urea to the SCR catalyst so as to supply NH.sub.3 to the SCR catalyst; and an AMOX provided downstream of the SCR catalyst in the direction of flow of the exhaust gas, and for removing NH.sub.3 having passed through the SCR catalyst. The DPF does not contain Pt or Pd, and contains Rh. The AMOX contains Pt.

A composite oxide catalyst includes Ce that is a first metal, La that is a second metal, and a third metal as contained metals. The third metal is a transition metal, or a rare-earth metal other than Ce and La. A Ce content in the contained metals is higher than or equal to 5 mol % and lower than or equal to 95 mol %. An La content in the contained metals is higher than or equal to 2 mol % and lower than or equal to 93 mol %. A content of the third metal in the contained metals is higher than or equal to 2 mol % and lower than or equal to 93 mol %.

A composite oxide catalyst includes Ce that is a first metal, La that is a second metal, and a third metal as contained metals. The third metal is a transition metal, or a rare-earth metal other than Ce and La. A Ce content in the contained metals is higher than or equal to 5 mol % and lower than or equal to 95 mol %. An La content in the contained metals is higher than or equal to 2 mol % and lower than or equal to 93 mol %. A content of the third metal in the contained metals is higher than or equal to 2 mol % and lower than or equal to 93 mol %.