The present technology relates to perovskite materials for oxygen storage. In one aspect, the perovskite material includes at least one platinum group metal (PGM) andat least one perovskite compound selected from the group consisting of formula (a): La.sub.xMO.sub.3 and formula (b): La.sub.(1-y)Sr.sub.yMO.sub.3, wherein: M is selected from the group consisting of Co, Cu, Fe, Mn and Ni; x is about 0.7 to about 1.1; and y is 0 to about 0.8, and wherein M, x, and y are independently variable for each one of said perovskite compounds. In one exemplary method, the perovskite materials of the technology are employed to treat automotive exhaust gas. In one embodiment, the perovskite materials are included in the washcoat of an automotive catalytic converter.

An exhaust gas purification catalytic device 1 contains Pt, Pd, and Rh as catalytic metals. The catalytic metal Pt is loaded on silica-alumina which serves as a support, and Pt-loaded silica-alumina obtained by loading the Pt on the silica-alumina is contained in a catalytic layer with which an exhaust gas contacts first.

An exhaust gas purification catalytic device 1 contains Pt, Pd, and Rh as catalytic metals. The catalytic metal Pt is loaded on silica-alumina which serves as a support, and Pt-loaded silica-alumina obtained by loading the Pt on the silica-alumina is contained in a catalytic layer with which an exhaust gas contacts first.

The exhaust gas-purifying catalyst of the invention includes a noble metal, and crystallites that form CZ composite metal particles which serve as a carrier supporting the noble metal and contain at least zirconium (Zr) and cerium (Ce). The CZ composite oxide particles (crystallites) further contain crystal growth-suppressing fine particles which are fine metal particles comprising primarily a metallic element M that melts at 1,500° C. or above and which suppress crystal growth by the CZ composite oxide particles. The content of the metallic element M included in the CZ composite oxide particles, expressed in terms of the oxide thereof, is 0.5 mol % or less of the total oxide.

The exhaust gas-purifying catalyst of the invention includes a noble metal, and crystallites that form CZ composite metal particles which serve as a carrier supporting the noble metal and contain at least zirconium (Zr) and cerium (Ce). The CZ composite oxide particles (crystallites) further contain crystal growth-suppressing fine particles which are fine metal particles comprising primarily a metallic element M that melts at 1,500° C. or above and which suppress crystal growth by the CZ composite oxide particles. The content of the metallic element M included in the CZ composite oxide particles, expressed in terms of the oxide thereof, is 0.5 mol % or less of the total oxide.

The invention relates to polyoxometalates represented by the formula (A.sub.n).sup.m+{M′.sub.s[M″M.sub.12X.sub.8O.sub.yR.sub.zH.sub.q]}.sup.m− or solvates thereof, corresponding supported polyoxometalates, and processes for their preparation, as well as corresponding metal-clusters, optionally in the form of a dispersion in a liquid carrier medium or immobilized on a solid support, and processes for their preparation, as well as their use in reductive conversion of organic substrate.

The invention relates to polyoxometalates represented by the formula (A.sub.n).sup.m+{M′.sub.s[M″M.sub.12X.sub.8O.sub.yR.sub.zH.sub.q]}.sup.m− or solvates thereof, corresponding supported polyoxometalates, and processes for their preparation, as well as corresponding metal-clusters, optionally in the form of a dispersion in a liquid carrier medium or immobilized on a solid support, and processes for their preparation, as well as their use in reductive conversion of organic substrate.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst composition comprises a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst composition comprises a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

In a method of manufacturing a bimetallic catalyst for reductively decomposing nitrate nitrogen, a powder including a trivalent iron oxide, a powder including a trivalent iron oxyhydroxide powder or a combination thereof is mixed in an aqueous solution. A copper precursor and a palladium precursor are mixed in the aqueous solution to form a precursor mixture. The precursor mixture is dried. The dried precursor mixture is fired at a temperature from about 300° C. to about 450° C. to form a fired product. The fired product is reduced by a reducing agent. A hydrochloric acid solution is mixed in the aqueous solution, or mixed with the copper precursor or the palladium precursor.