Nissan Motor Company Limited

Toru Sekiba

Katsuo Suga

Masanori Nakamura

Hironori Wakamatsu

Hirofumi Yasuda

Kazuyuki Shiratori

Hiroshi Akama

Shinji Yamamoto

Junji Ito

Yasunari Hanaki

Fumihiro Uchikawa

Shigeru Chida

Akihide Okada

A purifying catalyst includes catalyst powder composed of a transition metal oxide of which an average particle diameter is within 1 nm to 2 &#x3bc;m and in which an electron binding energy of oxygen is shifted to an energy side lower than 531.3 eV. The purifying catalyst shows good purification performance even when noble metal is not contained as an essential component.

Purifying catalyst

A method of producing catalyst powder of the present invention has a step of precipitating a transition metal particle and a base-metal compound in a reversed micelle substantially simultaneously, and a step of precipitating a noble metal particle in the reversed micelle. By this method, it is possible to obtain catalyst powder which restricts an aggregation of noble metal particles even at the high temperature and is excellent in the catalytic activity.

Catalyst powder, exhaust gas purifying catalyst, and method of producing the catalyst powder

A method of producing catalyst powder of the present invention has a step of precipitating a carrier in a reversed micelle, and a step of precipitating at least one of a noble metal particle and a transition metal particle in the reversed micelle in which the carrier is precipitated. By this method, it is possible to obtain catalyst powder excellent in heat resistance and high in the catalytic activity.

Catalyst powder, method of producing the catalyst powder, and exhaust gas purifying catalyst

A catalyst which suppresses aggregation of metal particles and which has superior heat resistance. In the catalyst, metal particles are supported by a surface of a carrier while being partially embedded therein.

Catalyst, exhaust gas purification catalyst, and method for manufacturing same

A method of producing catalyst powder of the present invention has a step of precipitating any one of a noble metal particle () and a transition metal particle () in a reversed micelle (); a step of precipitating, in the reversed micelle () in which any one of the noble metal particle () and the transition metal particle () is precipitated, a porous support material () which supports the noble metal particle () and the transition metal particle (); and a step of precipitating the other of the noble metal particle () and the transition metal particle () in the reversed micelle () in which any one of the noble metal particle ().

In a powdery catalyst (), a porous carrier () has a complex part () configured to hold a noble metal particle (), the complex part being composed of a transition metal material and a constituent material of the porous carrier ().

Powdery catalyst, exhaust-gas purifying catalyzer, and powdery catalyst production method

A method of producing catalyst powder of the present invention has a step of precipitating a noble metal particle () and a porous carrier () in a reversed micelle substantially simultaneously; and a step of precipitating a transition metal particle () in the reversed micelle. By this method, it is possible to obtain catalyst powder which restricts an aggregation of the noble metal particles even at a high temperature and is excellent in a catalytic activity.

An exhaust gas purifying method for a fuel cell vehicle comprises preparing an exhaust gas purifying system for the fuel cell vehicle, the exhaust gas purifying system including a methane removal catalyst for accelerating the conversion of methane into hydrogen and carbon monoxide. The methane removal catalyst comprises a catalytic ingredient including at least one of rhodium, platinum and palladium.

Exhaust gas purifying method for fuel cell vehicle and exhaust gas purifying system for fuel cell vehicle

Exhaust gas purifying method and system for fuel cell vehicle

The catalyst for the purification of exhaust gas in the form of monolithically-constructed catalyst with a catalyst component-loaded layer contains at least palladium and metallic aluminate powder as catalyst components, which metallic aluminate powder containing at least one element selected from the group consisting of cobalt, nickel and zinc. The method of manufacturing the catalyst for the purification of exhaust gas is characterized in that an alumina composite oxide is obtained by dissolving or dispersing fine grain alumina hydrate colloid and a water-soluble salt of at least one selected from the group consisting of cobalt, nickel and zinc into water, drying it by removing water, and then conducting calcining thereof.

Catalysts for the purification of exhaust gas and method of

The invention relates to a first catalyst for purifying an exhaust gas. The first catalyst has a substrate and a catalytic coating formed thereon. This catalytic coating has first and second grains. The first grain includes a porous carrier supporting thereon at least one of palladium and rhodium. The second grain includes a double oxide supporting thereon at least one of platinum and palladium. This double oxide is represented by a formula of (La.sub.1-x A.sub.x).sub.1-.alpha. BO.sub..delta. where A is at least one element selected from barium, potassium and cesium, B is at least one of iron, cobalt, nickel and manganese, 0&lt;X&lt;1, 0&lt;.alpha.&lt;0.2, and .delta. is a number such that a net electric charge of the first double oxide becomes zero. The invention further relates to a second catalyst similar to the first catalyst. The first grain of the second catalyst includes a porous carrier supporting thereon at least one of platinum, palladium, rhodium and iridium. The second grain of the second catalyst includes a double oxide represented by a formula of (La.sub.1-x A.sub.x).sub.1-.alpha. BZr.sub..beta. O.sub..delta. where A, B, x, .alpha. and .delta. are defined as above and 0&lt;.beta.&lt;1. The first and second catalysts are each improved in NOx absorption capability and capable of purifying NOx contained in an oxygen rich exhaust gas, even after the passage of an exhaust gas of high temperature for a long time through these catalysts.

Catalyst for purifying oxygen rich exhaust gas

A catalyst system for the purification of exhaust gas comprises at least two catalysts disposed on an exhaust system side of an engine and at least containing palladium as a catalyst component. In this case, each of catalysts disposed on upstream side and downstream side contains a given amount of an alkaline earth metal compound as an oxide conversion per 1 L of a carrier.

Catalyst system for the purification of exhaust gas

A catalyst for the purification of exhaust gas comprises a combination of palladium carried on cerium oxide and palladium carried on alumina, or further rhodium carried on alumina, in which a weight ratio of palladium carried on cerium oxide to palladium carried on alumina is 2:8-8:2. Preferably, the cerium oxide contains at least one of zirconium, lanthanum, neodymium and praseodymium, or the alumina contains at least one of zirconium, lanthanum, neodymium, cerium, strontium and barium. This catalyst develops excellent purification performances against exhaust gas of oxidizing atmosphere to reducing atmosphere.

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Yokohama, Japan

Toru Sekiba