Toyota Jidosha Kabushiki Kaisha

Cataler Corporation

Ichiro Hachisuka

Naoyuki Hara

Takeru Yoshida

Hirotaka Ori

Kazunobu Ishibashi

Michihiko Takeuchi

Yasuo Ikeda

The present invention provides an exhaust gas purification catalyst comprising a base material, and a two or more layered catalyst coating layer, formed on the base material, wherein the two or more layers have upper and lower layers, and wherein the upper layer contains a large amount of noble metal per liter of the base material more than that of the lower layer, and the lower layer contains a large amount of an oxygen storage/release material per liter of the base material more than that of the upper layer. This exhaust gas purification catalyst has more excellent HS purifying performance than conventional catalysts while maintaining purifying performance against NOx and the other exhaust gas components.

Catalyst for purifying exhaust gas

An NOsorption-and-reduction type catalyst is made which includes a hydrogen generating catalyst in which Rh is loaded on a support including an AlO&#x2014;ZrOcomposite oxide. Since the AlO&#x2014;ZrOcomposite oxide exhibits a basicity lower than ZrO, SOare less likely to approach so that it is possible to suppress the sulfur poisoning of Rh. Moreover, the AlO&#x2014;ZrOcomposite oxide exhibits higher heat resistance than ZrO, and it has a function of improving the steam reforming reaction activity of Rh in the same manner as ZrO. Therefore, the post-durability NOpurifying ability of the NOsorption-and-reduction type catalyst is improved.

Catalyst for hydrogen generation and catalyst for purifying of exhaust gas

A noble metal and an NOsorption member are loaded on a support which includes composite particles having a structure including a core portion in which ZrOis a major component and a superficial portion formed on a surface of the core portion and including an oxide, whose basicity is lower than ZrO, more than the core portion. The composite particles exhibit a high basicity at the inside and a low basicity on the surface by AlOor TiOwhich exists more in the surface. Accordingly, the sulfur-poisoning resistance is improved, and, at the same time, the post-durability NOpurifying ability is improved.

Exhaust gas purification catalyst

A catalyst for purifying exhaust gases which can suppress an active ingredient, such as an alkali metal, which reacts with a substrate from moving to the substrate, thereby preventing a decrease in strength such as thermal shock resistance of the substrate. In production, first, a first oxide layer composed mainly of an oxide which has a high reactability with the active ingredient is formed on the substrate. Next, a second oxide layer composed mainly of an oxide which has a low reactability with the active ingredient is formed on the first oxide layer. Then, a catalyst layer loaded at least with a noble metal and the active ingredient is formed on the second oxide layer. This second oxide layer suppresses transfer of the active ingredient and some active ingredient which has passed through the second oxide layer is caught by the first oxide layer owing to its reaction.

Catalyst for purifying exhaust gases

A catalyst for purifying exhaust of an internal combustion engine is prepared by mixing first powders in which at least Pt is loaded on a first support and second powders in which at least Rh is loaded on a second support and loading NO occluding material, for example an alkaline-earth metal, alkali metal or rare-earth metal, at least on the first support. In such catalyst, the second support is made of a stabilized zirconia stabilized by alkaline-earth metal or rare-earth element. The second support, having been become alkaline by the alkaline-earth metal or the rare-earth element, is excellent in absorbing performance of the steam (H O), so that the steam reforming reaction by Rh advances sufficiently. Therefore, the created hydrogen greatly contributes to the reduction of NO and to the sulfur poisoning prevention of the NO occluding material. Also, the oxidizing ability of Pt is maintained high, Rh sufficiently exhibits the steam reforming reaction activity and the sulfur poisoning of NO occluding material is restrained. An exhaust gas from an internal combustion engine is combusted where mixed gas of rich atmosphere containing excessive fuel is supplied to mixed gas of lean atmosphere containing excessive oxygen like a pulse. The exhaust gas is then introduced to the catalyst wherein the exhaust gas is purified.

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Nagoya, Japan

Ichiro Hachisuka