Abstract: An exhaust gas-purifying catalyst includes a support provided with one or more through-holes through which exhaust gas flows, and a catalytic layer supported by the support and containing an oxygen storage material. The exhaust gas-purifying catalyst includes a first section to which the exhaust gas is supplied, and a second section to which the exhaust gas having passed through the first section is supplied. The catalytic layer includes a layered structure of a first catalytic layer containing platinum and/or palladium and a second catalytic layer containing rhodium in the first catalytic section and further includes a third layer containing rhodium in the second section. The second section is smaller in oxygen storage material content per unit volumetric capacity than the first section.

Abstract: The exhaust gas purification catalyst according to the present invention has a substrate 54, a lower layer 57 disposed on this substrate 54, and an upper layer 58 disposed on this lower layer 57. The upper layer 58 is provided with a first catalyst and a second catalyst, and the lower layer 57 is provided with a first catalyst. This first catalyst has Al2O3 as a carrier and Pt and Pd as noble metals supported on the Al2O3, while the second catalyst typically has an Al2O3—ZrO2—TiO2 complex oxide as a carrier and has Pd as a noble metal supported on the Al2O3—ZrO2—TiO2 complex oxide. Moreover, the upper layer 58 has a hydrocarbon adsorbent 68.

Abstract: The exhaust gas purification catalyst according to the present invention has a substrate 54, a lower layer 57 disposed on this substrate 54, and an upper layer 58 disposed on this lower layer 57. The upper layer 58 is provided with a first catalyst and a second catalyst, and the lower layer 57 is provided with a first catalyst. This first catalyst has Al2O3 as a carrier and Pt and Pd as noble metals supported on the Al2O3, while the second catalyst typically has an Al2O3—ZrO2—TiO2 complex oxide as a carrier and has Pd as a noble metal supported on the Al2O3—ZrO2—TiO2 complex oxide. Moreover, the upper layer 58 has a hydrocarbon adsorbent 68.

Abstract: The oxidation catalyst for exhaust gas purification provided by the present invention includes a support supporting a noble metal that catalyzes the oxidation of carbon monoxide (CO). The support is mainly constituted by a composite metal oxide including, in terms of oxides, Al and Zr, or Al, Zr and Ti at the following mass ratios: Al2O3 40 to 99% by mass, ZrO2 1 to 45% by mass, and TiO2 0 to 15% by mass.

Abstract: The present invention provides an exhaust gas purification catalyst which has a structure which prevents competitive adsorption of HC, CO, and NOx and enables effective utilization of an NOx storage reduction type catalyst. The exhaust gas purification catalyst of the present invention is characterized by having an NOx storage reduction type catalyst layer which contains at least one type of NOx storage material which is selected from an alkali metal or an alkali earth metal and Pt and/or Rh on a substrate and having an oxidation catalyst layer which carries Pt and/or Pd on the NOx storage reduction type catalyst layer.

Abstract: An exhaust gas-purifying catalyst includes a support provided with one or more through-holes through which exhaust gas flows, and a catalytic layer supported by the support and containing an oxygen storage material. The exhaust gas-purifying catalyst includes a first section to which the exhaust gas is supplied, and a second section to which the exhaust gas having passed through the first section is supplied. The catalytic layer includes a layered structure of a first catalytic layer containing platinum and/or palladium and a second catalytic layer containing rhodium in the first catalytic section and further includes a third layer containing rhodium in the second section. The second section is smaller in oxygen storage material content per unit volumetric capacity than the first section.

Abstract: The exhaust gas-purifying catalyst includes a substrate provided with one or more through-holes through which exhaust gas flows, and a catalyst layer which is supported by the substrate and contains precious metals and an oxygen storage material. The exhaust gas-purifying catalyst contains a first part to which the exhaust gas is supplied, and a second part to which the exhaust gas having passed through the first part is supplied and is smaller in the content of the oxygen storage material per unit volume than that of the first part.

Abstract: An exhaust emission control apparatus that is used with an internal combustion engine to use both a NOx retention member and a catalyst while avoiding a decrease in the exhaust gas purification capacity. A NOx occlusion reduction type catalyst is placed in an exhaust path of an internal combustion engine. The NOx occlusion reduction type catalyst includes a base material. The base material includes an exhaust inflow cell, which is closed at its downstream side; and an exhaust outflow cell, which is closed at its upstream side and is adjacent to the first cell with the partition wall positioned in between. The exhaust inflow cell is configured so that a NOx retention layer is formed on the inner surface thereof, and the exhaust outflow cell is configured so that a catalyst layer is formed on the inner surface thereof, respectively.

Abstract: This invention is intended to ensure that an exhaust gas purification device with an NOx storage reduction catalyst and a particulate filter is able to fully utilize an original NOx storage capability of the NOx storage reduction catalyst. For this end, in addition to the filter 40 disposed upstream relative to the NOx storage reduction catalyst 22, the purification device includes a fuel supply element 42 for supplying a fuel so that the fuel is mixed with exhaust gas that flows into the filter, and an ozone feeder 30 for supplying ozone so that the ozone is mixed with exhaust gas that flows into the NOx storage reduction catalyst at a downstream position relative to the filter 40.

Abstract: One object of the present invention is to provide an exhaust emission control apparatus for an internal combustion engine that is capable of improving the NOx purification performance. An exhaust emission control apparatus being placed in an exhaust path of an internal combustion engine, comprising: an NOx retention material; ozone injection means for injecting ozone into an exhaust gas being positioned upstream from the NOx retention material; an HC adsorbent adsorbing HC contained in the exhaust gas; and a catalyst being placed in a region where desorbed NOx and desorbed HC contact each other. The HC adsorbent is prepared so as to desorb adsorbed HC at the same time as NOx being stored in the NOx retention material is desorbed.

Abstract: An exhaust emission control apparatus that is used with an internal combustion engine to occlude and reduce NOx without blocking the exhaust gas purification function of a catalyst. An NOx occlusion reduction type catalyst and ozone supply device are provided in an exhaust path of the internal combustion engine. The NOx occlusion reduction type catalyst includes a cell into which an exhaust gas flows. An inner surface of the cell is coated with a NOx retention layer and a catalyst layer so that the NOx retention layer and the catalyst layer are provided in the order named from the inner surface of the cell.

Abstract: A NOx occlusion reduction type catalyst positioned in an exhaust path of an internal combustion engine, which can be used with the internal combustion engine to permit efficient use of ozone when ozone is added to an exhaust gas. A NOx oxidation gas supply device supplies air or ozone (O3) So that air or ozone (O3) mixes with an exhaust gas flowing into the NOx occlusion reduction type catalyst. The ozone supply is performed when the temperature of the NOx occlusion reduction type catalyst is lower than a temperature at which a NOx occlusion acceleration effect is produced by the air supply. After the temperature of the NOx occlusion reduction type catalyst reaches the temperature at which the NOx occlusion acceleration effect is produced by the air supply, the air supply is performed and the ozone supply is shut off.