Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Akio Isogai

Mareo Kimura

Masakuni Ozawa

Shinichi Matsumoto

Naoto Miyoshi

Hideaki Muraki

Shiroh Kondoh

Yoshio Shimura

Yoshiyuki Mizutani

Tomoyuki Inui

An exhaust gas purifying catalyst of this invention is a catalyst for mainly removing nitrogen oxides contained in exhaust gases, comprising: crystalline copper silicate expressed by the following composition formula; M.sub.n+m (Cu.sub.n Al.sub.m Si.sub.96-n-m O.sub.192).16H.sub.2 O, where M denotes one of sodium (Na) and potassium (K), and n+m&lt;27. An exhaust gas purifying process of this invention employs the above-mentioned crystalline copper silicate catalyst. The exhaust gas purifying catalyst and the exhaust gas purifying process employing the same purify the nitrogen oxides (NOx) by facilitating the reaction between hydrocarbons (HC) and nitrogen oxides (NOx) contained in the exhaust gases more preferentially than the reaction between hydrocarbons (HC) and oxygen (O.sub.2) contained therein, thereby purifying the nitrogen oxides (NOx) and hydrocarbons (HC) at high efficiency.

Exhaust gas purifying catalyst and exhaust gas purifying process

A catalyst for purification of exhaust gases, comprising a support substrate, a catalyst carrier layer formed on the support substrate and catalyst ingredients loaded on the catalyst carrier layer, wherein the catalyst carrier layer comprises alumina, cerium oxide, zirconium oxide and at least one oxide of rare earth element except cerium and lanthanum, and at least a part of cerium oxide, zirconium oxide and oxide of rare earth element except cerium and lanthanum is present in the form of composite oxide and/or solid solution. The catalyst for purification of exhaust gases is capable of purifying exhaust gases containing carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx).

Catalyst for purification of exhaust gases

A catalyst for the purification of exhaust gases comprising a catalyst carrier layer and catalyst ingredients carried thereon, is capable of enhancing the purification property by suppressing the growth of cerium oxide particles and preventing the formation of LaAlO.sub.3. This catalyst has two composition types. One is a binary composition catalyst comprising oxides of cerium and zirconium in the catalyst carrier layer and the other is a ternary composition catalyst comprising oxides of cerium, zirconium and lanthanum in the catalyst carrier layer.

Catalyst for the purification of exhaust gas

A catalyst for purifying exhaust gases comprises: a perovskite-type complex oxide represented by the general formula Ln.sub.1-x A.sub.x MO.sub.3, wherein Ln represents at least one rare earth metal, A presents at least one alkaline earth metal and M represents at least one transition metal, and 0&lt;x&lt;1; at least one heat resistant complex oxide; and at least one precious metal. The heat resistant complex oxide is one of ABO.sub.3, LnAlO.sub.3 or Ln.sub.2 B.sub.2 O.sub.7, wherein A represents at least one alkaline earth metal, B represents at least one of Ti, Zr and Hf, and Ln represents at least one rare earth metal, and the precious metal is at least one of Pt, Pd, Rh, Ir, Ru and Os. The catalyst is usable as a temperature of 900.degree. C. or above without sintering or reduction of a catalytic activity.

Catalyst for purifing exhaust gases

A high temperature sliding element is provided with a metallic film formed of any one of metals Ni, Mn, Cr, Fe and Co, and alloys of these metals on a sliding surface of a substrate of carbide ceramics or nitride ceramics in accordance with physical vapor deposition. When the substrate and a sliding counterpart ceramic member are slid in a high temperature atmosphere 500.degree. C. or higher with the metallic film intervening therebetween, wear due to sliding motion between the substrate and the counterpart ceramic member can effectively be reduced. The metallic film forms an oxidized sliding surface layer at the high temperature.

High temperature sliding element and method for preventing high

An alumina catalyst support stable at high temperatures comprises transformative alumina having a purity not less than 99.95% impregnated with lanthanum in an amount of 1.5 to 6 wt % based on the weight of the alumina. The alumina catalyst support has a surface area of at least 60 m.sup.2 /g after heating at 1200.degree. C. for 5 hours.

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Nagoya, Japan

Akio Isogai