148results about How to "Improve exhaust gas purification performance" patented technology

An exhaust gas purification catalyst has a substrate, a lower catalyst layer that is formed on the substrate and contains at least one of Pd and Pt, and an upper catalyst layer that is formed on the lower catalyst layer and contains Rh. A region that does not contain the upper catalyst layer is disposed on the exhaust gas upstream side of this exhaust gas purification catalyst. The lower catalyst layer includes a front-stage lower catalyst layer on the exhaust gas upstream side and a rear-stage lower catalyst layer on the exhaust gas downstream side. The front-stage lower catalyst layer contains an oxygen storage material.

An exhaust gas purifying catalyst includes a substrate that defines an exhaust gas passage; a lower catalyst layer formed over the substrate, and an upper catalyst layer formed over the lower catalyst layer. The lower catalyst layer has a lower catalytic precious metal that contains at least one of Pt and Pd, and a lower-layer carrier that supports the lower catalytic precious metal. The upper catalyst layer has an upper catalytic precious metal that contains Rh, and an upper-layer carrier that supports the upper catalytic precious metal. The upper-layer carrier includes an inorganic mixed oxide that contains Ce, Zr, Al, Nd, and at least one element selected from the group consisting of rare earth elements other than Ce and alkaline earth elements. The Nd is unevenly distributed in covering layers that covers surfaces of interior regions within the inorganic mixed oxide.

In an exhaust gas purification catalyst comprising a honeycomb support and a catalytic layer that is formed on wall surfaces of each cell of the honeycomb support and contains active alumina and a mixed oxide containing Ce, Zr and Nd and doped with catalytic precious metal, the mixed oxide has a CeO2 / ZrO2 mass ratio of 1.4 or more and the ratio of Nd2O3 / (CeO2+ZrO2+Nd2O3) in the mixed oxide is 20 mass % or less.

Catalytic converter comprises a carrier having exhaust gas passages therein, a lower catalytic layer coated over the carrier and comprising hollow oxide powder loaded with catalytic metal, and an upper catalytic layer coated over the lower catalytic layer, directly exposed to exhaust gas flowing in the exhaust gas passages and comprising solid oxide powder loaded with catalytic metal. The hollow oxide powder may be ceria or alumina base oxide. Further it may be mixed oxide such as Ce—Zr mixed oxide or La contained alumina as well.

It is an object of the present invention to provide a catalyst for the exhaust gas purification having excellent ignition performance and NOx purification performance. The present invention provides a catalyst for the exhaust gas purification which comprises a catalytically active component (I) having palladium and barium supported on a refractory inorganic oxide (A); and a catalytically active component (II) having at least either of rhodium and platinum on a refractory inorganic oxide (B), a method for the production thereof, and a method for purifying an exhaust gas using such a catalyst.

An outboard motor includes a multi-cylinder engine which includes cylinders longitudinally oriented and vertically paralleled in a cylinder block, a cylinder head arranged at a rearward position of the cylinder blocks, and a crankcase arranged at a forward position of the cylinder block, the cylinder head having an outlet of an exhaust port at one side thereof. An exhaust system for the outboard motor includes an exhaust manifold which communicates the outlet of the exhaust port with an exhaust outlet opening, the exhaust manifold including a first exhaust gas passage extending in a vertical direction for gathering exhaust gas discharged from the outlet of each exhaust port and a second exhaust gas passage extending in a vertical direction adjacently to the first exhaust gas passage, and a catalyst unit is provided on the way of the second exhaust gas passage.

The exhaust gas-purifying catalyst includes at least one of a first composite oxide represented by a formula A(Al2-xBx)O4 and a second composite oxide represented by a formula (Al2-yCy)O3, wherein element A is a divalent transition metal other than platinum-group elements, each of elements B and C is a transition metal other than platinum-group elements, x satisfies 0<x<2, and y satisfies 0<y<2.

Provided is an exhaust gas purification catalyst that combines reduction of pressure loss and enhancement of purification performance. This invention provides an exhaust gas purification catalyst comprising a wall-flow-type substrate and first and second catalytic layers. The first catalytic layer is provided to the interior of a partition wall, in contact with an entrance cell, from an exhaust inlet-side end in the running direction, having a length L1 less than Lw. The second catalytic layer is provided to the interior of a partition wall, in contact with an exit cell, from an exhaust outlet-side end in the running direction, having a length L2 less than Lw. An internal portion of partition wall in contact with entrance cell has a substrate-exposing segment near the exhaust outlet-side end.

A exhaust gas purification apparatus is provided with; a substrate having a wall-flow structure and including entry-side cells, exit-side cells, and a porous partition; a first catalyst region formed in small diameter pores having relatively small pore diameters among internal pores in the partition; and a second catalyst region formed in large diameter pores having relatively large pore diameters among the internal pores in the partition. The first catalyst region contains a support and any one or two species of precious metal selected from Pt, Pd, and Rh loaded on the support, while the second catalyst region contains a support and any one or two species of precious metal selected from Pt, Pd, and Rh loaded on the support and other than at least the precious metal present in the first catalyst region.

An engine device in which a DPF (1), which is one of the components of an engine (70), is disposed in the engine (70) with high rigidity, which eliminates a measure against exhaust gas for each device of a vehicle, and which can improve the usability of the engine (70). The engine device comprises the engine (70) having an exhaust manifold (71) and the DPF (1) for purifying the exhaust gas exhausted from the engine (70). The cylinder head (72) of the engine (70) comprises filter support bodies (19a-19c) for supporting the DPF (1). The DPF (1) is connected to the exhaust manifold (71), and also connected to the cylinder head (2) with the filter support bodies (19a-19c) interposed therebetween.

An exhaust gas purification catalyst having an excellent exhaust gas purification ability while reducing the increase in pressure loss. Exhaust gas purification catalyst includes entrance cell, exit cell, and a wall-flow substrate having partition wall to separate these cell, a catalytic layer formed from exhaust inlet-side ends in the extending direction in sections of the interior of partition wall facing entrance cell, and a catalytic layer formed on the surface of partition wall facing exit cell from exhaust outlet-side ends in the extending direction of partition wall, having a length shorter than the entire partition wall length.

An exhaust gas purification catalyst includes a substrate, and a first catalyst layer formed on the substrate, the first catalyst layer containing palladium and / or platinum and alumina doped with an alkaline-earth metal element. The exhaust gas purification catalyst has a correlation coefficient ρAl,AE given by the following formula of 0.75 or more:ρAl,AE=CAl,AEσAl⁢σAE.(1)

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 Lw 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 Lw of the partition. The first catalyst layer and the second catalyst layer are configured to partially overlap with each other in the extending direction.