Manganese-cobalt (MnCo) spinel oxide nanowire arrays are synthesized at low pressure and low temperature by a hydrothermal method. The method can include contacting a substrate with a solvent, such as water, that includes MnO4- and Co2 ions at a temperature from about 60 C. to about 120 C. The method preferably includes dissolving potassium permanganate (KMnO4) in the solvent to yield the MnO4 ions. the substrate is The nanoarrays are useful for reducing a concentration of an impurity, such as a hydrocarbon, in a gas, such as an emission source. The resulting material with high surface area and high materials utilization efficiency can be directly used for environment and energy applications including emission control systems, air/water purifying systems and lithium-ion batteries.

An exhaust gas-purifying catalyst of the present invention comprising a substrate, a first catalyst layer comprising a first supported catalyst, a second supported catalyst, palladium, and a first nitrogen oxide storage material, and a second catalyst layer comprising a third supported catalyst having an alloying rate of platinum and palladium of 40% or more and a second nitrogen oxide storage material, wherein a mass of the second supported catalyst is greater than a mass of the first supported catalyst and greater than a mass of the third supported catalyst.

An exhaust system for treating an exhaust gas from an internal combustion engine is disclosed. The system comprises a modified lean NO.sub.x trap (LNT), a urea injection system, and an ammonia-selective catalytic reduction catalyst. The modified LNT comprises a first layer and a second layer. The first layer comprises a NO.sub.x adsorbent component and one or more platinum group metals. The second layer comprises a diesel oxidation catalyst zone and an NO oxidation zone. The diesel oxidation catalyst zone comprises a platinum group metal, a zeolite, and optionally an alkaline earth metal. The NO oxidation zone comprises a platinum group metal and a carrier. The modified LNT stores NO.sub.x at temperatures below about 200 C. and releases at temperatures above about 200 C. The modified LNT and a method of using the modified LNT are also disclosed.

Synergized platinum group metals (SPGM) with ultra-low PGM loadings employed as close-coupled (CC) three-way catalysts (TWC) systems with varied material compositions and configurations are disclosed. SPGM CC catalysts in which ZPGM compositions of binary or ternary spinel structures supported onto support oxides are coupled with commercialized PGM UF catalysts and tested under Federal Test Procedure FTP-75 within TGDI and PI engines. The performance of the TWC systems including SPGM CC (with ultra-low PGM loadings) catalyst and commercialized PGM UF catalyst is compared to the performance of commercialized PGM CC and PGM UF catalysts. The disclosed TWC systems indicate that SPGM CC TWC catalytic performance is comparable or even exceeds high PGM-based conventional TWC catalysts, with reduced tailpipe emissions.

The present disclosure provides a catalyst composition comprising a catalytically active platinum group metal (PGM) component disposed on or impregnated in a magnetic ferrite support material, wherein the magnetic ferrite support material is capable of inductive heating in response to an applied alternating electromagnetic field. Further provided are catalyst articles comprising such compositions, and components comprising such catalyst articles, and further comprising a conductor associated with the catalyst article for receiving current and generating an alternating electromagnetic field in response thereto, wherein the conductor is positioned such that the generated alternating electromagnetic field is applied to at least a portion of the catalyst composition, inductively heating the catalyst composition directly at the catalytic site. Also provided are exhaust gas treatment systems including such components and/or articles, and methods of treating emissions utilizing such components and systems.

Active catalysts for the treatment of a low temperature exhaust gas stream are provided containing copper oxides dispersed on a spinel oxide for the direct, lean removal of nitrogen oxides from the exhaust gas stream. The low temperature, direct decomposition is accomplished without the need of a reductant molecule. In one example, CuO.sub.x may be dispersed as a monolayer on a metal oxide support, such as Co.sub.3O.sub.4 spinel oxide, synthesized using an incipient wetness impregnation technique. The CuO.sub.x/Co.sub.3O.sub.4 catalyst system converts nitric oxide to nitrogen gas with high product specificity, avoiding the production of a significant concentration of the undesirable N.sub.2O product.

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.

An object of the present invention is to provide an exhaust gas purification catalyst composition and an exhaust gas purification catalyst, each of which utilizes a phosphorus capturing material that enables solving a problem of MAO, and in order to achieve the object, a complex oxide containing Mg, Ba, and Al, wherein the complex oxide has a spinel-type crystal structure, and wherein a molar ratio of a Mg content to an Al content in the complex oxide is 0.010 or more and 0.25 or less is used as a phosphorus capturing material.

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.

An exhaust gas-purifying catalyst includes a support and a catalytic metal supported thereby. The support includes a composite oxide represented by AO.xB.sub.2-C.sub.O.sub.3, wherein A represents at least one of an element having a valence of 1 and an element having a valence of 2, B represents an element having a valence of 3, C represents one or more elements selected from iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, x represents a numerical value of 1 to 6, and represents a numerical value greater than 0 and less than 2. The catalytic metal includes one or more precious metals selected from rhodium, palladium, and platinum.