The present disclosure is directed to compositions for use in oxygen capture applications, for example in three-way catalysts (TWC) systems. In some embodiments, the compositions comprise composites of aggregated and/or fused primary particles, the aggregated and/or fused primary particles collectively having the formulae [MnO.sub.x].sub.y:[La.sub.zMnO.sub.3].sub.1y; wherein x is in a range from about 1 to 2.5; y is in a range from about 1 to about 30 wt %, or from about 1 to about 20 wt % or from about 2-10 wt % or from about 2 to about 5 wt %; and z is about 0.7 to about 1.1; and the La.sub.zMnO.sub.3 is a crystalline perovskite phase; the aggregated and/or fused primary particles of the composite having a mean surface area in a range of from about 25 to about 60 m.sup.2/g, preferably from about 27 to about 45 m.sup.2/g. In preferred embodiments, these compositions further comprise low levels of at least one platinum group metal (PGM), preferably Pd.

Compositions, articles, and methods related to a three-way-catalyst composition comprising a perovskite-type compound of formula (I): La.sub.zB.sub.1-qB.sub.qO.sub.3 or formula (II): [BO.sub.x].sub.y:[La.sub.zBO.sub.3].sub.1-y and a non-redox active component; wherein B or B is Fe, Mn, Co, Ni, Cu, Ti, or Zr; q is in a range from about 0 to about 0.5; x is from about 1 to about 2.5; y is from about 1 to about 30 wt %; z is about 0.6 to about 1.1; is in a range from about 0 to about 0.6.

A catalyst obtainable by exsolving particles of Ni, Co and/or a mixture of Ni and Co from a perovskite metal oxide of formula (I) (M.sup.1.sub.aM.sup.2.sub.b)(CO.sub.xNi.sub.yM.sup.3.sub.z)O.sub.3, wherein M.sup.1 and M.sup.2 are each independently an alkali earth metal or a rare earth metal, M.sup.3 is Ti or Cr, 0a1, 0b1, 0<a+b1, 0x<1, 0y<1, 0z<1, x+y+z=1 and where at least one of x and y>0. The invention includes methods of converting this catalyst into one or more catalytically active forms. The catalysts and the activated forms of same are useful in the catalysing CO oxidation and/or NO oxidation.

A three-way catalyst composition, and its use in an exhaust system for internal combustion engines, is disclosed. The composition can comprise a compound of formula (I): A.sub.x-yA.sub.yB.sub.1-zB.sub.zO.sub.3 and a promoter metal component, wherein A is an ion of a metal of group 2 or 3 of the periodic table of elements; wherein A is an ion of a metal of group 1, 2, or 3 of the periodic table of elements; wherein B and B are ions of metal of groups 4, 6, 7, 8, 9, 10, 11, or 13 of the periodic table of elements; wherein x is from 0.7 to 1; wherein y is from 0 to 0.5; and wherein z is from 0 to 0.5.

The structured catalyst for oxidation for exhaust gas purification includes a support having a porous structure constituted by a zeolite-type compound, and at least one type of oxidation catalyst that is present in the support and selected from the group consisting of metal and metal oxide, the support having channels that communicate with each other, and the oxidation catalyst being present in at least the channels of the support.

Provide is a functional structural body that can suppress aggregation of metal oxide nanoparticles and prevent functional loss of metal oxide nanoparticles, and thus exhibit a stable function over a long period of time. A functional structural body (1) includes: a skeletal body (10) of a porous structure composed of a zeolite-type compound; and at least one type of metal oxide nanoparticles (20) containing a perovskite-type oxide present in the skeletal body (10), the skeletal body (10) having channels (11) that connect with each other, and the metal oxide nanoparticles (20) being present at least in the channels (11) of the skeletal body (10).

A functional structural body includes a skeletal body of a porous structure composed of a zeolite-type compound, and at least one type of metallic nanoparticles present in the skeletal body, the skeletal body having channels connecting with each other, the metallic nanoparticles being present at least in the channels of the skeletal body.

An organic matter decomposition catalyst that contains a perovskite type complex oxide represented by A.sub.xB.sub.yM.sub.zO.sub.w, wherein A contains 90 at % or more of at least one element selected from the group consisting of Ba and Sr, B contains 80 at % or more of Zr, M is at least one element selected from the group consisting of Mn, Co, Ni, and Fe, y+z=1, x>1, z<0.4, and w is a positive value that satisfies electrical neutrality.

The present disclosure provides perovskite catalytic materials and catalysts comprising platinum-group metals and perovskites. These catalysts may be used as oxygen storage materials with automotive applications, such as three-way catalysts. They are also useful for water or CO.sub.2 reduction, or thermochemical energy storage.

A co-catalyst system for the removal of NO.sub.x from an exhaust gas stream has a layered oxide and a spinel of formula Ni.sub.0.15Co.sub.0.85CoAlO.sub.4. The system converts to nitric oxide to nitrogen gas with high product specificity. The layered oxide is configured to convert NO.sub.x in the exhaust gas stream to an N.sub.2O intermediate, and the spinel is configured to convert the N.sub.2O intermediate to N.sub.2.