Honda Motor Co., Ltd.

Naohiro Sato

Yuji Yasui

Hideki Matsunaga

Norio Suzuki

Hiroshi Ohno

Tadao Nakatsuji

Masafumi Sakota

Eiji Hashimoto

Atsushi Furukawa

Osami Yamamoto

Katsuji Wada

Tetsuo Endo

Yuichi Matsuo

Tomoko Morita

Koichi Inaba

Chiaki Seki

Yusuke Imai

Hisao Haga

Jun Iwamoto

Go Motohashi

Fumihiro Mondori

Naoki Oya

The present invention provides an exhaust purification filter with which pressure loss can be reduced, the filter having high exhaust purification performance and granular-substance-filtering performance. The exhaust purification filter comprises a filter base material having a wall flow structure, and an exhaust purification catalyst supported on a dividing wall of the filter base material, the exhaust purification filter being such that: a median pore diameter (D50) of the filter base material according to a volumetric basis is 15 μm or greater; and the exhaust purification catalyst is unevenly supported on a high-density layer, in which the density of the exhaust purification catalyst is relatively high, and a low-density layer, in which the density of the exhaust purification catalyst is relatively low.

Exhaust purification filter

Provided is an exhaust purification filter that is able to reduce pressure loss and that has high exhaust purification performance and particulate matter trapping performance. This exhaust purification filter comprises a filter substrate having a wall flow structure, and an exhaust purification catalyst supported on a partition wall of the filter substrate. The volume-based median pore diameter (D50) of the filter substrate is 18 μm or greater, the full width at half maximum of the pore distribution of the filter substrate is 7 μm to 15 μm, and the exhaust purification catalyst is supported in an unevenly distributed manner in a high-density layer in which the density of the exhaust purification catalyst is relatively high and a low-density layer in which the density of the exhaust purification catalyst is relatively low.

An exhaust purification system is provided that can decrease the load acting on a device treating PM, even when switched to stoich operation. The exhaust purification system includes: a PM treatment device, a three-way purification catalyst, an LAF sensor, and an ECU () that performs feedback control so that an LAF sensor output (Vex) becomes a target value (Vop) determined so that the three-way purification reaction is optimized during stoich operation. The ECU () includes a fuel controller () that determines a fuel injection amount (Gfuel) so that a state in which an air/fuel ratio of the air/fuel mixture is leaner than stoich and a state richer than stoich are alternately realized by modulating a fuel correction amount (dGfuel) determined so as to cause the LAF sensor output (Vex) to converge to the target value (Vop) by employing a predetermined modulation algorithm.

Exhaust purification system for internal combustion engine

An exhaust gas purifying system includes: a SCR catalyst which has a function of reducing NOx and absorbing NO; an upstream catalyst which is provided at the upstream side of the SCR catalyst and has a three-way purification function; and an air-fuel ratio controller which controls the air-fuel ratio of the air-fuel mixture. The controller calculates the NOstorage amount of the SCR catalyst (S2), calculates a value of the NOx correlation parameter that increases in response to the NOx discharge amount (S4), sets the stoichiometry determination threshold value to a small value as the NOstorage amount increases (S5), and changes the operation mode of the engine to the stoichiometry operation mode in which the air-fuel ratio is controlled to stoichiometry when the value of the NOx correlation parameter is larger than the stoichiometry determination threshold value (S6, S9).

Exhaust gas purifying system of internal combustion engine

An exhaust purification system for an internal combustion engine is provided that can steadily maintain a NOx purification rate of a selective reduction catalyst to be high without allowing the fuel economy or marketability to deteriorate. The exhaust purification system includes a NO&#x2014;NOx ratio adjustment mechanism that causes a NO&#x2014;NOx ratio to change; and a NO&#x2014;NOx ratio perturbation controller that executes NO&#x2014;NOx ratio perturbation control so that a NObalance of the selective reduction catalyst in a predetermined time period, with NOadsorption being positive and NOrelease being negative, is 0. Herein, NO&#x2014;NOx ratio perturbation control is defined as control that alternately executes NOincrease control to cause the NO&#x2014;NOx ratio to be greater than a reference value near 0.5, and NOdecrease control to cause the NO&#x2014;NOx ratio to be less than the reference value.

Disclosed is a NOx purifying catalyst which is capable of removing NOx sufficiently efficiently even during operations at low temperatures such as operations in diesel cars. Specifically disclosed is a NOx purifying catalyst for processing NOx in an exhaust gas by performing lean/rich control of air-fuel ratio of the exhaust gas. This NOx purifying catalyst comprises at least a first catalyst layer containing a &#x3b2; zeolite containing iron element and a second catalyst layer containing a noble metal, a cerium oxide material and a specific zirconium oxide material. The second catalyst layer and the first catalyst layer are sequentially arranged on a carrier in such a manner that the first catalyst layer forms the uppermost layer.

NOx purifying catalyst

An exhaust cleaning method and exhaust cleaning apparatus for an internal combustion engine () in which a fuel is fed and burned under periodical rich/lean combustion conditions. In a fuel reformer () disposed independently of an exhaust channel () in the engine (), the fuel for the internal combustion engine () is reformed to produce a reformed gas containing carbon monoxide. The reformed gas is supplied to the exhaust to be introduced into an exhaust converter () having, disposed therein, a catalyst which adsorbs and reduces nitrogen oxides. The nitrogen oxides contained in the exhaust gas are adsorbed and reduced. Thus, the nitrogen oxides contained in the exhaust are removed at a high efficiency.

Method of exhaust cleaning for internal combustion engine and exhaust cleaner

Disclosed is a NOx purifying catalyst which is capable of removing NOx sufficiently efficiently even during operations at low temperatures such as operations in diesel cars. Specifically disclosed is a NOx purifying catalyst for processing NOx in an exhaust gas by performing lean/rich control of air/fuel ratio of the exhaust gas. This NOx purifying catalyst comprises at least a first catalyst layer containing a &#x3b2; zeolite containing iron element and a cerium oxide material and a second catalyst layer containing a noble metal, a cerium oxide material and a heat-resistant inorganic oxide. The second catalyst layer and the first catalyst layer are sequentially arranged on a carrier in such a manner that the first catalyst layer forms the uppermost layer.

An internal combustion engine having a turbocharger is provided. The engine includes a turbine of the turbocharger located in an exhaust system of the engine, an upstream side catalyst located upstream of the turbine, a catalyst bypass passage bypassing the upstream side catalyst, a catalyst bypass passage on/off valve for opening and closing the catalyst bypass passage, and a first exhaust gas recirculation passage for recirculating a part of exhaust gases from a portion between the upstream side catalyst and the turbine to an intake system of the engine. The engine, that further includes a second exhaust gas recirculation passage for recirculating a part of exhaust gases from an upstream side of the upstream side catalyst to the intake system, and a switching valve for switching between the first exhaust recirculation passage and the second exhaust recirculation passage, is provided.

Internal combustion engine and control system for internal combustion engine

An exhaust gas purifying device for an internal combustion engine, comprises: an exhaust purifying catalyst; a NOx purifying catalyst disposed downstream of the exhaust purifying catalyst; upstream and downstream A/F detecting sensors disposed on upstream and downstream sides of the exhaust purifying catalyst, respectively; means for supplying a reducing agent to the NOx purifying catalyst when conducting a reduction control of the NOx; means for calculating an amount of reduced NOx in the NOx purifying catalyst; means for terminating the reduction control when the amount of reduced NOx exceeds a prescribed reduction termination threshold value; means for detecting a degree of deterioration of the exhaust purifying catalyst based on an output from the upstream and downstream A/F detecting sensors; a threshold value correcting means for correcting the reduction termination threshold value according to the degree of deterioration of the exhaust purifying catalyst; and a correction prohibiting means for prohibiting the correction of the reduction termination threshold value when an amount of Hand/or CHin the exhaust gas exceeds a prescribed correction prohibiting judgment value.

Exhaust gas purifying device for an internal combustion engine

The invention provides a catalyst for catalytically reducing nitrogen oxides in diesel engine exhaust gas by use of unburnt carbon contained in the diesel engine exhaust gas as a reducing agent, the catalyst comprising:

Catalyst and method for purification of diesel engine exhaust gas

A method comprising subjecting fuel to combustion while the combustion atmosphere of the fuel is oscillated periodically and alternately between rich and lean conditions, leading the exhaust gas formed to a catalytic reactor, and bringing the exhaust gas into contact with a catalyst in the catalytic reactor to conduct catalytic reduction of nitrogen oxides contained in the exhaust gas, wherein the catalyst comprises as catalyst components:

Method for catalytic reduction of nitrogen oxides

The invention provides a catalyst for catalytic reduction of nitrogen oxides contained in exhaust gases wherein fuel is supplied and subjected to combustion under periodic rich/lean conditions and the resulting exhaust gases are brought into contact therewith, which catalyst comprises: (A) a catalyst component A comprising (c) ceria or (d) praseodymium oxide or (e) an oxide and/or a composite oxide of at least two elements selected from the group consisting of cerium, zirconium, praseodymium, neodymium, terbium, samarium, gadolinium and lanthanum; (B) a catalyst component B comprising (d) a noble metal catalyst component selected from the group consisting of platinum, rhodium, palladium and oxides thereof and (e) a carrier; and (C) a catalyst component C comprising (f) a solid acid, and (g) a solid acid supporting an oxide of at least one element selected from the group consisting of vanadium, tungsten, molybdenum, copper, iron, cobalt, nickel and manganese.

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Wako, Japan

Naohiro Sato