The present invention provides processes for filtering undesired chemicals in streams of contaminated air for supply to confined areas. The processes provide (1) contacting air with a filter comprising by volume from about 5% to about 95% impregnated zirconium hydroxide, from about 5% to about 95% activated impregnated carbon, and optionally, up to about 50% ammonia removal material; and (2) supplying the contacted air to a confined area.

An exhaust gas purification catalyst that has an excellent exhaust gas purification performance while suppressing pressure loss increases. The exhaust gas purification catalyst is provided with a substrate having a wall-flow structure and having a partition; a first catalyst layer formed, in a region of an interior part of the partition that is in contact with an entrance cell, along the extending direction of the partition from an exhaust gas inflow-side end for less than the total length L.sub.w of the partition; and a second catalyst layer formed, in a region of an interior part of the partition that is in contact with an exit cell, along the extending direction of the partition from the exhaust gas outflow-side end for less than the total length L.sub.w of the partition. The first catalyst layer and the second catalyst layer are configured to partially overlap with each other in the extending direction.

An object of the present invention is to provide an exhaust gas purification catalyst for purifying exhaust gas, in particular, fine composite-metal particles contained therein, and a method for producing the same; the exhaust gas purification catalyst according to the present invention includes fine composite-metal particles containing Rh and Pd, wherein, when the fine composite-metal particles in the exhaust gas purification catalyst are analyzed by STEM-EDX, the average ratio of the amount of Pd with respect to the total amount of Rh and Pd in the fine composite-metal particles is 1.7 atomic % or more and 24.8 atomic % or less.

A multi-scaled oxygen storage material wherein cobalt element is complexed with a size of an atom or hundreds of nanometers or smaller in a ceria-zirconia solid solution and a method for preparing the same are provided.

Specifically, The multi-scaled oxygen storage material contains a ceria-zirconia solid solution, a cobalt dopping contained in the solid solution in the form of an atom and a cobalt-based nanocluster dispersed in the solid solution as cobalt oxide and exhibits a microstructure distinguished from that of the existing ceria-zirconia (CZO)-based oxygen storage material as well as remarkably improved oxygen storage and release ability, and the method for preparing the same is provided.

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.3—CeO.sub.2—ZrO.sub.2 ternary composite oxide (ACZ material) and an Al.sub.2O.sub.3—ZrO.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.3—ZrO.sub.2 binary composite oxide of the support.

A catalyst composition comprising a mixture of (a) a zeolite compound in an amount of from 10% to 60% by weight, wherein the zeolite compound comprises cations selected from Fe.sup.2+, Fe.sup.3+, Cu.sup.+, Cu.sup.2+ or mixtures thereof, and (b) a ceria/zirconia/alumina composite oxide, wherein the alumina content in said composite oxide is in the range of 20 to 80% by weight, in particular of 40 to 60% by weight,
a catalyst comprising such catalyst composition and its use for exhaust gas after-treatment of diesel and lean burn engines.

Composites of mixed metal oxides for an exhaust gas purifying catalyst comprise the following co-precipitated materials by weight of the composite: zirconia in an amount in the range of 55-99%; titania in an amount in the range of 1-25%; a promoter and/or a stabilizer in an amount in the range of 0-20%. These composites are effective as supports for platinum group metals (PGMs), in particular rhodium.

[Summary]

[Problem]

The problem addressed by the present invention lies in providing an exhaust gas purification filter which can efficiently treat particulate matter in exhaust gas.

[Solution]

The present invention provides an exhaust gas purification filter including a substrate comprising a plurality of porous partitions, wherein the partitions form an exhaust gas flow path, a porous catalytic layer is provided on the partitions and the catalytic layer having a thickness of 10 μm or greater is provided over at least 20% of the total length of the partitions in the lengthwise direction thereof, and the catalytic layer having a thickness of 10 μm or greater is not present on the partitions 15 mm from an outflow side.

An emissions treatment system for an exhaust stream of an internal combustion engine including hydrocarbons, carbon monoxide, and nitrogen oxides is provided. The disclosed system can include an exhaust conduit in fluid communication with the internal combustion engine via an exhaust manifold; a first three-way conversion catalyst (TWC-1) located downstream of the internal combustion engine in the exhaust conduit; an SCR-HCT catalyst comprising a selective catalytic reduction catalyst and a hydrocarbon trap downstream of the TWC-1 in the exhaust conduit; and a third catalyst downstream of the SCR-HCT combination in the exhaust conduit, the third catalyst comprising a platinum group metal (PGM) e.g., in an amount effective to oxidize hydrocarbons. Methods of making and using such systems and components thereof are also provided.

Provided is an exhaust gas purification catalyst having high catalytic activity enabling combustion of PM (particulate matter) at low temperatures and excellent thermal resistance, an exhaust gas purification device and filter having high combustion efficiency of PM and excellent durability, and a method for producing the catalyst. The exhaust gas purification catalyst of the present invention is composite oxide particles containing at least one alkali metal, Si, and Zr.