An exhaust gas purification underfloor catalyst characterized in having a catalyst layer having a lower layer and an upper layer, the lower layer containing alumina and CeO.sub.2, the noble metal content of the lower layer being at most 0.5 mass % in relation to the mass of the lower layer, the upper layer containing Rh, alumina, and CeO.sub.2, the amount of noble metals other than Rh contained being 1 mol % or less in relation to the total amount of noble metals contained in the upper layer, the total amount of CeO.sub.2 contained in the lower layer and the upper layer being 14 g/L to 30 g/L, the amount of CeO.sub.2 contained in the upper layer being 7 g/L to 25 g/L, and the amount of CeO.sub.2 contained in the lower layer being 20% or more of the amount of CeO.sub.2 contained in the upper layer.

The present invention relates to a new strategy for capturing NO.sub.x using a two-step process.

A high durability catalyst for decomposing volatile organic compounds (VOCs) or sublimable organic substances, generated inside a polymer film production furnace, at a high conversion rate is provided. A method for purifying a gas inside a polymer film production furnace with the use of the catalyst is also provided.

Provided are a purification catalyst for a gas inside a polymer film production furnace, which contains a mixed oxide composed of a manganese-based oxide containing manganese and potassium and having a cryptomelane structure, and copper oxide; and a method for purifying a gas inside a polymer film production furnace, comprising a step 1 of bringing hot air containing volatile and/or sublimable organic substances, generated during production of a polymer film by the polymer film production furnace, into contact with the catalyst provided inside or outside the furnace, at a temperature in the range of 200 to 350 C. to decompose the organic substances oxidatively, and a step 2 of refluxing all or a part of a resultant decomposition gas to the polymer film production furnace.

An extruded honeycomb catalyst for nitrogen oxide reduction according to the selective catalytic reduction (SCR) method in exhaust gases from motor vehicles includes an extruded active carrier in honeycomb form having a first SCR catalytically active component and with a plurality of channels through which the exhaust gas flows during operation, and a washcoat coating having a second SCR catalytically active component being applied to the extruded body, wherein the first SCR catalytically active component and the second SCR catalytically active component are each independently one of: (i) vanadium catalyst with vanadium as catalytically active component; (ii) mixed-oxide catalyst with one or more oxides, in particular those of transition metals or lanthanides as catalytically active component; and (iii) an Fe- or a Cu-zeolite catalyst.

Zero-PGM (ZPGM) catalyst materials including pseudo-brookite compositions for use in diesel oxidation catalyst (DOC) applications are disclosed. The disclosed doped pseudo-brookite compositions include A-site partially doped pseudo-brookite compositions, such as, Sr-doped and Ce-doped pseudo-brookite compositions, as well as B-site partially doped pseudo-brookite compositions, such as, Fe-doped, Co-doped Ni-doped, and Ti-doped pseudo-brookite compositions. The disclosed doped pseudo-brookite compositions, including calcination at various temperatures, are subjected to a DOC standard light-off (LO) test methodology to assess/verify catalyst activity as well as to determine the effect of the use of a dopant in an A-site cation or a B-site cation within a pseudo-brookite composition. The disclosed doped pseudo-brookite compositions exhibit higher NO oxidation catalyst activities when compared to bulk powder pseudo-brookite, thereby indicating improved thermal stability and catalyst activity when using a dopant in an A-site cation or in a B-site cation within a pseudo-brookite composition.

A noble metal-free lanthanum transition metal perovskite catalyst material. The noble metal-free lanthanum transition metal perovskite catalyst material may include a two phase mixture of a lanthanum transition metal perovskite with an alkali or alkaline earth metal carbonate, a lanthanum transition metal perovskite doped with an alkali or alkaline earth metal, or a combination thereof. The lanthanum transition metal perovskite catalyst material provides direct decomposition of NOx into N.sub.2 and O.sub.2 without the presence of a noble metal and in the presence of excess O.sub.2.

The exhaust gas cleaning catalyst according is provided with a substrate and a catalyst coat layer formed on a surface of the substrate. The catalyst coat layer is formed as a laminate structure having an upper layer and a lower layer. The upper layer is a Pd-free layer that does not contain Pd, and the lower layer is a Pd-containing layer. In addition, when a region of the lower layer that corresponds to 20% of the length of the exhaust gas cleaning catalyst from the exhaust gas inlet side end towards the exhaust gas outlet side of the exhaust gas cleaning catalyst is divided into four equal regions to be each 5% of the length, the relationship A>B>C is satisfied, where A, B, and C represents the Pd content in the first, second, and third region respectively.

The present disclosure relates to zero-PGM (ZPGM) catalysts including variations of Nickel-doped Copper-Manganese spinel for improved catalyst performance at the stoichiometric condition for use within three-way catalyst (TWC) applications. The ZPGM catalyst material compositions within the aforementioned ZPGM catalysts are expressed with general formulas of Cu.sub.1-XNi.sub.XMn.sub.2O.sub.4 (A-site substitution) and Cu.sub.1Mn.sub.2-XNi.sub.XO.sub.4 (B-site substitution). The ZPGM catalysts are subjected to a TWC isothermal steady-state sweep test to assess the catalytic performance (e.g., NO conversion). Test results indicate the ZPGM catalysts exhibit higher NO conversions, at stoichiometric condition and lean conditions, when Ni substituted the B-site cation of the CuMn spinel as compared to Ni substituted the A-site cation of the CuMn spinel. Additionally, NO conversions of the ZPGM catalysts are significantly affected, at the stoichiometric condition, by the molar ratio of the Ni dopant within the A or B-site cation of the CuMn spinel.

The present invention is directed towards a catalytic coating comprising a composite oxide which accelerates soot combustion. The oxide is used in a catalytic coating in soot filters for the abatement of noxious pollutants in exhaust gases from combustion processes. A process for the production of catalytic coatings comprising these composite oxides is also given.

The nitric oxide reducing catalyst contains a negatively charged copper cluster.