N.e. Chemcat Corporation

Toshinori Okajima

Makoto Nagata

Tomoaki Ito

Kyohei Yamaguchi

Yasuyuki Banno

Takashi Hihara

Nobunori Okui

Takeshi Mende

An exhaust gas purification device is capable of reducing the amount of NOx emissions generated at the time of cold start. An exhaust gas purification device includes a urea injection valve, a metal honeycomb, a temperature sensor, and an SCR catalyst in an exhaust passage. It is possible for an exhaust gas temperature of exhaust gas passing through the metal honeycomb to be increased by the metal honeycomb that is capable of being electrically heated by control executed by a control unit ECU. The exhaust gas temperature is detected by the temperature sensor. Based on a temperature-versus-ammonia adsorption amount profile stored in advance in a storage unit of the control unit ECU, ammonia is pre-adsorbed onto the metal honeycomb and the SCR catalyst, and the metal honeycomb is electrically heated at the time of cold start after the temperature detected by the temperature sensor becomes lower than 150&#xb0; C.

Exhaust gas purification device

An exhaust gas purification catalyst apparatus, which is superior in oxidation performance of, in particular, nitrogen monoxide, among hydrocarbons, carbon monoxide, nitrogen oxides and particulate components such as soot, included in exhaust gas from a lean burn engine, and combustion performance of light oil. The exhaust gas purification apparatus arranged with an oxidation catalyst (DOC) comprising a noble metal component for oxidizing carbon monoxide, hydrocarbons, in particular, nitrogen monoxide among nitrogen oxides, and for combusting light oil, a catalyzed soot filter (CSF) including a noble metal component for collecting a particulate component such as soot and removing by combustion (oxidation). The oxidation catalyst (DOC) has a catalyst layer where platinum (Pt), palladium (Pd) and barium oxide (BaO) are supported on alumina (AlO) having a pore size of 12 to 120 nm, and ratio of platinum and palladium is 1:1 to 11:2 in weight equivalent.

Exhaust gas purifier

An exhaust gas purification catalyst apparatus. The apparatus has a noble metal component for oxidizing NOx in an exhaust gas discharged from a diesel engine, a reducing agent spraying means for supplying the reducing agent selected from a urea component or an ammonia component, and a selective reduction catalyst (SCR) not comprising a noble metal for removing by reduction NOx by contacting with the reducing agent, in this order from the upstream side of an exhaust gas passage. Activity of the selective reduction catalyst (SCR) is maintained by setting that the noble metal component of the oxidation catalyst (DOC) comprises platinum and palladium, and ratio of platinum particles existing alone is 20% or less, or average particle diameter of the noble metal is 4 nm or larger, and by suppressing volatilization of platinum from the oxidation catalyst (DOC), even when catalyst bed temperature increases up to 900&#xb0; C.

Off gas purification device

An ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of NO or NO. The ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal on an inorganic base material including any of a composite oxide (A) having at least titania and silica as main components, alumina, and a composite oxide (B) consisting of alumina and silica; and a catalyst layer (upper layer) including a composite oxide (C) consisting of at least silica, tungsten oxide, ceria and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is silica: 20% by weight or less, tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.

Ammonia oxidation catalyst, exhaust gas purification device using same, and exhaust gas purification method

Ammonia oxidation catalyst being superior in heat resistance and capable of suppressing by-production of NO and leakage of ammonia. The ammonia oxidation catalyst (AMOX) removes surplus ammonia, in selectively reducing nitrogen oxides by adding urea or ammonia and using a selective catalytic reduction (SCR) catalyst, into exhaust gas, wherein the ammonia oxidation catalyst is made by coating at least two catalyst layers having a catalyst layer (lower layer) including a catalyst supported a noble metal element on a composite oxide (A) having titania and silica as main components, and a catalyst layer (upper layer) including a composite oxide (C) consisting of tungsten oxide, ceria, and zirconia, at the surface of an integral structure-type substrate, wherein a composition of the composite oxide (C) is tungsten oxide: 1 to 50% by weight, ceria: 1 to 60% by weight, and zirconia: 30 to 90% by weight.

Growing community of inventors

Shizuoka, Japan

Toshinori Okajima