Abstract: An exhaust-gas-purifying system of an internal combustion engine of the present disclosure sets a reduction treatment necessity flag to ON when an input gas temperature of an exhaust gas introduced into an exhaust-gas-purifying catalyst is higher than a reference temperature. Then, it is determined whether reduction treatment execution conditions in which the reduction treatment necessity flag has been set to ON and the input gas temperature has decreased and falls within a preset temperature range up to a reference temperature or lower are satisfied. Then, when it is determined that reduction treatment execution conditions are satisfied, a reduction treatment in which an air-fuel ratio of an intake gas supplied into the engine is adjusted to be richer than a stoichiometric air-fuel ratio is performed, and the reduction treatment necessity flag is set to OFF.

Abstract: An exhaust-gas-purifying system of an internal combustion engine of the present disclosure sets a reduction treatment necessity flag to ON when an input gas temperature of an exhaust gas introduced into an exhaust-gas-purifying catalyst is higher than a reference temperature. Then, it is determined whether reduction treatment execution conditions in which the reduction treatment necessity flag has been set to ON and the input gas temperature has decreased and falls within a preset temperature range up to a reference temperature or lower are satisfied. Then, when it is determined that reduction treatment execution conditions are satisfied, a reduction treatment in which an air-fuel ratio of an intake gas supplied into the engine is adjusted to be richer than a stoichiometric air-fuel ratio is performed, and the reduction treatment necessity flag is set to OFF.

Abstract: An exhaust gas purification catalyst includes an alumina support, a silica layer, and active metal particles. The silica layer is formed on a surface of the alumina support. The active metal particles are formed of platinum and palladium, the platinum and the palladium being supported on the silica layer. A ratio of fine particles having a particle size of 2.0 nm or less to all the active metal particles is 50% or higher in terms of the number of particles, the fine particles being included in the active metal particles. A ratio of fine alloy particles having a palladium content ratio of 10 at % to 90 at % to all the fine particles is 50% or higher in terms of the number of particles, the fine alloy particles being included in the fine particles.

Abstract: An exhaust gas purification catalyst includes an alumina support, a silica layer, and active metal particles. The silica layer is formed on a surface of the alumina support. The active metal particles are formed of platinum and palladium, the platinum and the palladium being supported on the silica layer. A ratio of fine particles having a particle size of 2.0 nm or less to all the active metal particles is 50% or higher in terms of the number of particles, the fine particles being included in the active metal particles. A ratio of fine alloy particles having a palladium content ratio of 10 at % to 90 at % to all the fine particles is 50% or higher in terms of the number of particles, the fine alloy particles being included in the fine particles.

Abstract: An exhaust gas purification catalyst includes: a support formed of alumina and yttria; and platinum and palladium that are supported on the support. An yttria content in the support is 2 mass % to 15 mass %. A content ratio of the platinum to the palladium is in a range of 1 to 10 by mass ratio. At least a portion of the platinum and at least a portion of the palladium constitute a solid solution. A diffraction peak of a (311) plane of a crystal including the platinum, the palladium and the solid solution is present at 81.5° or higher in a range of 81.2° to 82.1°, the diffraction peak being identified by an X-ray diffraction method using CuK? rays.

Abstract: An exhaust gas purification catalyst includes: a support containing alumina as a major component; and an active species fine particle containing silver sulfate as a major component and having an average crystallite size of 3 nm to less than 100 nm, in which the active species fine particle is supported on a surface of the support.

Abstract: A wall flow type particulate filter is arranged inside the exhaust passage of an internal combustion engine where combustion is performed under an excess of oxygen. The particulate filter carries a solid acid. The solid acid has an acid strength which is higher than the acid strength of sulfurous acid and lower than the acid strength of sulfuric acid. To remove the ash from the particulate filter, ash atomization processing for rendering the state of the particulate filter a state where the exhaust gas which flows into the particulate filter is lowered in concentration of oxygen and the particulate filter is raised in temperature is temporarily performed.

Abstract: A wall flow type particulate filter is arranged inside the exhaust passage of an internal combustion engine where combustion is performed under an excess of oxygen. The particulate filter carries a solid acid. The solid acid has a Hammett acidity function smaller than ?0.83 and larger than ?12 in the standard state. To remove the ash from the particulate filter, ash atomization processing for rendering the state of the particulate filter a state where the exhaust gas which flows into the particulate filter is lowered in concentration of oxygen and the particulate filter is raised in temperature is temporarily performed.

Abstract: A wall flow type particulate filter is arranged inside the exhaust passage of an internal combustion engine where combustion is performed under an excess of oxygen. The particulate filter carries an ash atomization agent. To remove the ash from the particulate filter, ash atomization processing for rendering the state of the particulate filter a state where the exhaust gas which flows into the particulate filter is lowered in concentration of oxygen and the particulate filter is raised in temperature is temporarily performed.

Abstract: A wall flow type particulate filter (24) adapted to be arranged in an exhaust passage of an internal combustion engine in which combustion is performed in an excess of oxygen carries a solid acid. The solid acid has an acid strength which is higher than the acid strength of sulfurous acid and lower than the acid strength of sulfuric acid.

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: A wall flow type particulate filter is arranged inside the exhaust passage of an internal combustion engine where combustion is performed under an excess of oxygen. The particulate filter carries a solid acid. The solid acid has an acid strength which is higher than the acid strength of sulfurous acid and lower than the acid strength of sulfuric acid. To remove the ash from the particulate filter, ash atomization processing for rendering the state of the particulate filter a state where the exhaust gas which flows into the particulate filter is lowered in concentration of oxygen and the particulate filter is raised in temperature is temporarily performed.

Abstract: A method of removing ash from a wall flow type particulate filter which is arranged in an exhaust passage of an internal combustion engine in which combustion is performed in an excess of oxygen for trapping particulate matter in exhaust gas, using a solid acid which is carried on the particulate filter, renders the state of the particulate filter a state where the exhaust gas which flows into the particulate filter is lowered in concentration of oxygen and the particulate filter is raised in temperature, and then renders the state of the particulate filter a state where the exhaust gas which flows into the particulate filter in an oxidizing atmosphere contains SOx.

Abstract: An exhaust purification system of an internal combustion engine includes an NOX storage reduction catalyst device which is arranged in an engine exhaust passage. The NOX storage reduction catalyst device stores SOX simultaneously with NOX. When the stored SOX amount exceeds a predetermined allowable amount, the SOX is made to be released by SOX release control which raises the temperature of the NOX catalyst device to the SOX releasable temperature, then makes the air-fuel ratio of the exhaust gas which flows into the NOX catalyst device the stoichiometric air-fuel ratio or rich. The NOX catalyst device has a residual SOX storage amount which finally remains even if performing SOX release control depending on the temperature of the NOX catalyst device when performing SOX release control. The system uses the residual SOX storage amount of the current SOX release control as the basis to calculate the SOX release speed at each timing in the current SOX release control.

Abstract: A wall flow type particulate filter is arranged inside the exhaust passage of an internal combustion engine where combustion is performed under an excess of oxygen. The particulate filter carries a solid acid. The solid acid has a Hammett acidity function smaller than ?0.83 and larger than ?12 in the standard state. To remove the ash from the particulate filter, ash atomization processing for rendering the state of the particulate filter a state where the exhaust gas which flows into the particulate filter is lowered in concentration of oxygen and the particulate filter is raised in temperature is temporarily performed.

Abstract: A wall flow type particulate filter (24) adapted to be arranged in an exhaust passage of an internal combustion engine in which combustion is performed in an excess of oxygen carries a solid acid. The solid acid has an acid strength which is higher than the acid strength of sulfurous acid and lower than the acid strength of sulfuric acid.

Abstract: A wall flow type particulate filter is arranged inside the exhaust passage of an internal combustion engine where combustion is performed under an excess of oxygen. The particulate filter carries an ash atomization agent. To remove the ash from the particulate filter, ash atomization processing for rendering the state of the particulate filter a state where the exhaust gas which flows into the particulate filter is lowered in concentration of oxygen and the particulate filter is raised in temperature is temporarily performed.

Abstract: A method of removing ash from a wall flow type particulate filter which is arranged in an exhaust passage of an internal combustion engine in which combustion is performed in an excess of oxygen for trapping particulate matter in exhaust gas, using a solid acid which is carried on the particulate filter, renders the state of the particulate filter a state where the exhaust gas which flows into the particulate filter is lowered in concentration of oxygen and the particulate filter is raised in temperature, and then renders the state of the particulate filter a state where the exhaust gas which flows into the particulate filter in an oxidizing atmosphere contains SOx.

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 present invention is intended to improve a SOx reduction rate which is a ratio of an amount of SOx reduction with respect to an amount of SOx occlusion in SOx poisoning recovery processing. In the present invention, in the SOx poisoning recovery processing in which the SOx occluded in an NOx storage reduction catalyst is reduced by decreasing the air fuel ratio of an exhaust gas flowing into the NOx storage reduction catalyst to a predetermined air fuel ratio in a repeated manner, the length of a period in which the air fuel ratio of an exhaust gas flowing into the NOx storage reduction catalyst is decreased is made longer in a relatively early time during the processing than in a relatively late time during the processing.