The present invention provides a methane oxidation catalyst comprising one or more noble metals supported on zirconia, wherein the zirconia comprises tetragonal zirconia and monoclinic zirconia, and wherein the weight ratio of tetragonal zirconia to monoclinic zirconia is in the range of from 1:1 to 31:1. The invention further provides a process for preparing a methane oxidation catalyst, a methane oxidation catalyst thus prepared and a method of oxidizing methane.

A lean burn engine exhaust treatment articles comprising a low temperature lean NO.sub.x trap (LT-LNT) composition and methods for their use is disclosed. A lean burn engine exhaust gas treatment system including the lean burn engine exhaust treatment articles is also disclosed. The low temperature lean NO.sub.x trap (LT-LNT) compositions can comprise a washcoat layer on a carrier substrate, the washcoat layer including a platinum group metal component impregnated on a first support material comprising at least 50% alumina. The washcoat layer may further include a low temperature NO.sub.x storage material comprising a bulk particulate reducible metal oxide. Methods of monitoring the aging state of a lean burn oxidation catalyst in a lean burn engine catalyst system are also disclosed.

An oxidation catalyst for treating an exhaust gas produced by a compression ignition engine comprising: a substrate; a catalytic material disposed on the substrate, wherein the catalytic material comprises platinum (Pt); and a region comprising a capture material, wherein the capture material comprises a Pt-alloying metal disposed or supported on a refractory oxide, wherein the refractory oxide comprises at least 65% by weight of zirconia, wherein the region is arranged to contact the exhaust gas after the exhaust gas has contacted and/or passed through the catalytic material.

A lean NO.sub.x trap composition for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO), and the trapping and reduction of nitrogen oxides (NO.sub.x) is disclosed. The lean NO.sub.x trap composition can have a washcoat layer on a carrier substrate including a first support material comprising greater than 50% by weight of a reducible metal oxide; 10 to 30% by weight of alkaline earth metal supported on a second support material comprising a refractory metal oxide and 50% or less by weight of a reducible metal oxide and; and a platinum group metal component supported on at least one of the first support material and/or the second support material. A portion of the first support material may further include 0.5% to 10% by weight of an alkaline earth metal.

Provided are a method for producing a composite oxide and the composite oxide. The method includes steps of: (a) preparing a Ce aqueous solution not less than 80 mol % of which Ce ions are tetravalent, and a Zr aqueous solution; (b1) mixing the Zr aqueous solution and a portion of the Ce aqueous solution to prepare a mixed aqueous solution (X1); (c1) hydrothermally processing the solution (X1); (b2) adding the remainder of the Ce aqueous solution of step (a) to a colloidal solution (Y1) of a composite salt obtained from step (c1) to prepare a colloidal solution (Y2) of a composite salt; (c2) hydrothermally processing the solution (Y2); (d) mixing a colloidal solution (Y3) of a composite salt obtained from step (c2) with an alkaline solution and a surfactant to prepare a precipitate; and (e) calcining the precipitate.

Disclosed is a process for the preparation of 1,3,3,3-tetrafluoropropene, comprising: (a) a compound having the formula CF.sub.3-xCl.sub.xCHClCHF.sub.2-yCl.sub.y and in the presence of a compound catalyst, undergoes, through n serially-connected reactors, gas-phase fluorination with hydrogen fluoride, producing 1,2,3-trichloro-1,1,3-trifluoropropane, and 1,2-dichloro-1,1,3,3-tetrafluoropropane; in said formula, x=1, 2 or 3; y=1 or 2, and 3x+y5; (b) 1,2,3-trichloro-1,1,3-trifluoropropane, and 1,2-dichloro-1,1,3,3-tetrafluoropropane undergo, in the presence of a dehalogenation catalyst, gas-phase dehalogenation with hydrogen, producing 3-chloro-1,3,3-trifluoropropene, and 1,1,3,3-tetrafluoropropene; (c) 3-chloro-1,3,3-trifluoropropene and 1,1,3,3-tetrafluoropropene undergo, in the presence of a fluorination catalyst, gas-phase fluorination with hydrogen fluoride, producing 1,3,3,3-tetrafluoropropene. The present invention is primarily used to produce 1,3,3,3-tetrafluoropropene.

An exhaust gas purification catalyst includes: a first catalyst unit that consists of a hydrogen generating catalyst including a noble metal and an oxide that contains lanthanum, zirconium and an additional element such as neodymium; a second catalyst unit that consists of an oxygen storage/release material and a perovskite oxide disposed in contact with the oxygen storage/release material and represented by the general formula La.sub.xM1.sub.1-xM2O.sub.3-, where La is lanthanum, M1 is at least one element selected from the group consisting of barium (Ba), strontium (Sr) and calcium (Ca), M2 is at least one element selected from the group consisting of iron (Fe), cobalt (Co) and manganese (Mn), x satisfies 0<x1, and satisfies 01; and a holding material that holds the first catalyst unit and the second catalyst unit in a mutually separated state.

A core-shell support, comprising: a core which comprises at least one oxygen storage/release material selected from the group consisting of ceria-zirconia based solid solutions and alumina-doped ceria-zirconia based solid solutions; and a shell which comprises a rare earth-zirconia based composite oxide represented by a composition formula: (Re.sub.1-xCe.sub.x).sub.2Zr.sub.2O.sub.7+x (where Re represents a rare earth element, and x represents a number of 0.0 to 0.8) and with which an outside of the core is coated, the rare earth-zirconia based composite oxide comprising crystal particles having a pyrochlore structure, and the rare earth-zirconia based composite oxide having an average crystallite diameter of 3 to 9 nm.

A catalytic converter with excellent OSC performance and No.sub.x purification performance. The catalytic converter includes a substrate with a cell structure and a catalyst layer formed on a cell wall surface of the substrate. The catalyst layer has a catalyst layer arranged on the upstream side and a catalyst layer arranged on the downstream side in an exhaust gas flow direction on the substrate. The catalyst layer on the upstream side includes a support containing an Al.sub.2O.sub.3CeO.sub.2ZrO.sub.2 ternary composite oxide (ACZ material) and an Al.sub.2O.sub.3ZrO.sub.2 binary composite oxide (AZ material), and at least Rh that is a noble metal catalyst carried on the support, and the catalyst layer on the downstream side includes a support and Pd or Pt that is a noble metal catalyst carried on the support. In the support in the catalyst layer on the upstream side, the mass proportion of ACZ material/(ACZ material+AZ material) is in the range of 0.33 to 0.5, and greater than or equal to 75% mass Rh is carried on the Al.sub.2O.sub.3ZrO.sub.2 binary composite oxide of the support.

Provided are a method for producing a composite oxide and the composite oxide, which finds use as an easy-to-handle catalyst material having a high reforming rate of hydrocarbon to hydrogen even when oxidized. The method includes the steps of: (a) preparing a Ce aqueous solution not less than 80 mol % of which Ce ions are tetravalent, and a Zr aqueous solution containing Zr ions; (b1) mixing the Zr aqueous solution and a portion of the Ce aqueous solution to prepare a mixed aqueous solution (X1); (c1) hydrothermally processing solution (X1); (b2) adding the remainder of the Ce aqueous solution prepared in step (a) to a colloidal solution (Y1) of a composite salt obtained from step (c1) to prepare a colloidal solution (Y2) of a composite salt; (c2) hydrothermally processing solution (Y2) obtained from step (b2); (d) mixing a colloidal solution (Y3) of a composite salt obtained from step (c2) with an alkaline solution and a surfactant to prepare a precipitate; and (e) calcining the precipitate.