Abstract: Exhaust gas clean-up catalysts that contain one or two or more noble metals chosen from the group platinum (Pt), rhodium (Rh), ruthenium (Ru), Iridium (Ir), osmium (Os) and other noble metals, and at least one of tungsten (W) metal or tungsten oxide and, optionally, at least one of niobium (Nb) metal, niobium oxide, molybdenum (Mo) metal, or molybdenum oxide, and which can also contain the metal oxide(s) ceria and/or zirconia if necessary, are especially useful for cleaning up hydrocarbons in exhaust gases.

Abstract: Exhaust gas clean-up catalysts that contain one or two or more noble metals chosen from the group platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), Iridium (), osmium (Os) and other noble metals and one, two or more metal oxides chosen from the group tungsten (W), niobium b) and molybdenum (Mo) oxides, and which can also contain the metal oxide(s) ceria and/or zirconia if necessary, are especially useful for cleaning up hydrocarbons in exhaust gases.

Abstract: A method for purifying an exhaust gas by simultaneously removing carbon monoxide, hydrocarbons, and nitrogen oxides contained in the exhaust gas, comprising bringing the oxygen rich exhaust gas into contact with an exhaust gas purifying catalyst comprised of at least one noble metal selected from the group consisting of platinum and palladium, at least one alkaline earth metal selected from the group consisting of barium, magnesium, calcium, and strontium, and at least one alkali metal selected from the group consisting of iron, nickel, and cobalt, supported on a carrier composed of a porous substance.

Abstract: A catalyst for purifying an exhaust gas for simultaneously removing carbon monoxide, hydrocarbons and nitrogen oxides contained in the exhaust gas under an oxygen rich atmosphere, comprising a carrier composed of a porous material, and barium oxide, lanthanum oxide and platinum supported on the carrier, and a method for purifying an exhaust gas by bringing the exhaust gas under an oxygen rich atmosphere into contact with the above-mentioned catalyst.

Abstract: An apparatus for decreasing nitrogen oxides in a combustion device of Stirling engine which performs continuous combustion includes a combustion chamber, means for supplying the combustion chamber with fuel and air, an exhaust passageway for discharging exhaust gas produced by combustion in the combustion chamber, a catalytic unit arranged in the exhaust passageway for purging toxic components contained in the exhaust gas discharged, and hydrogen supply means for supplying hydrogen gas to the exhaust gas which enters the catalytic unit. The hydrogen gas is supplied to the combustion exhaust gas which has entered the catalytic unit, and the combustion exhaust gas is then catalytically reduced in an environment of a comparatively low temperatures of less than 250.degree. C., whereby the nitrogen oxides in the exhaust gas are decreased.

Abstract: A NO.sub.x absorbent (18) which absorbs the NO.sub.x when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent (18) is lean and releases the absorbed NO.sub.x when the oxygen concentration of the exhaust gas flowing into the NO.sub.x absorbent (18) is lowered, is arranged in the exhaust passage of the engine. The amount of alkali metals, alkali-earth metals or rare-earth metals contained in the NO.sub.x absorbent (18) positioned on the downstream side, is made lower than the amount of alkali metals, alkali-earth metals or rare-earth metals contained in the NO.sub.x absorbent (18) positioned on the upstream side, to increase a reducing ability of the NO.sub.x absorbent (18) positioned on the downstream side as compared to the reducing ability of the NO.sub.x absorbent (18) positioned on the upstream side.

Abstract: A lean NOx reduction catalyst capable of reducing NOx through reaction of H.sub.2 with NOx at low temperatures below 350.degree. C. is installed in a downstream portion of an exhaust pipe of an internal combustion engine in or near a muffler. Such an NOx reduction catalyst comprises, for example, Pt/zeolite catalyst. An H.sub.2 generator is installed so as to supply the H.sub.2 to an inlet side of the NOx reduction catalyst. The H.sub.2 generator may include a reforming catalyst for reforming methanol, LPG, or natural gas to generate H.sub.2. The generated H.sub.2 flows to the NOx reduction catalyst where it reacts with NOx to purify the exhaust gas.

Abstract: A method for purifying an oxygen excess exhaust gas by catalytically reducing nitrogen oxides contained in the exhaust gas, which comprises bringing a catalyst comprising at least one noble metal supported on a carrier composed mainly of an oxide or a complex oxide of at least one metal selected from rare earth metals and metals of the group IV A of the periodic table of elements into contact the exhaust gas.

Abstract: Hydrogen gas from a hydrogen generator which creates hydrogen gas by the electrolysis of water or water vapor is supplied at the entrance to a catalyzer provided in an exhaust line. The catalyzer performs a catalytic reaction between hydrogen gas and nitrogen oxides to achieve decomposition into nitrogen gas and water vapor in the exhaust from an internal combustion engine. The nitrogen oxides are directly reduced with said hydrogen gas in a low temperature atmosphere not higher than 350.degree. C. to achieve efficient reduction in the nitrogen oxides. The improved method and apparatus provide a catalytic system with which the nitrogen oxides in the exhaust from a lean burnt engine or a diesel engine can be effectively reduced irrespective of the concentration of oxygen gas in the exhaust without impairing the good fuel economy of those engines.

Abstract: A noble metal base catalyst for decomposing a portion of NOx included in engine exhaust gas into intermediate products such as N.sub.2 O and NO.sub.2 is installed in an exhaust conduit of a lean burn engine. Further, an intermediate product decomposing means for decomposing the intermediate products produced by the noble metal base catalyst into N.sub.2 and O.sub.2 is installed downstream of the noble metal base catalyst. The noble metal base catalyst has a high thermal durability, and the noble metal base catalyst and the intermediate product decomposing means decompose NOx into N.sub.2 and O.sub.2 without a large amount of HC.

Abstract: 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<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.

Abstract: The exhaust gases, such as of an internal combustion engine are contacted with a catalyst containing copper in the presence of hydrocarbons in an oxidizing atmosphere, whereby nitrogen oxides are reduced from the exhaust gases. Then, the exhaust gases are preferably contacted with an oxidizing catalyst. The former catalyst contains copper loaded on a porous support formed from alumina, silica, silica-alumina or zeolite or mixture thereof. The support is preferably a monolithic body having a first portion loaded with copper and a second portion loaded with a metal or metals defining the oxidizing catalyst.

Abstract: A catalytic combustion type exhaust gas processing device wherein noxious/smelly components contained in exhaust gases are deodorized and purified through sequential oxidative decomposition by at least one catalyst layer composed of platinum and/or palladium catalyst and a copper-cerium catalyst comprising chemically active species of copper and cerium in a compounded form. The device can be applied effectively to a drying furnace, for example, used in a coating for automobile use.

Abstract: An exhaust gas purifying catalyst for oxidizing HC and CO and for reducing NOx is provided, which comprises at least one oxide of rare earth element, rhodium, and at least one of platinum and palladium loaded on alumina grains. The major amount of rhodium is dispersed on the oxide of rare earth element. Thus, the rhodium solidification into the alumina grains is prevented. Further, when cerium oxide accompanying lanthanum oxide, neodymium oxide or a mixture thereof is used as the oxide of rare earth element, the sintering of cerium oxide or palladium at a high temperature is suppressed since it forms a complex oxide with lanthanum oxide, neodymium oxide or a mixture thereof. Additionally, when stabilized alumina grains in which a rare earth element and an alkali earth element are present in a solid solution state are used, the deterioration of NOx purifying activity of the catalyst at a high temperature is suppressed.

Abstract: A catalyst for synthesizing hydrocarbons such as butane etc. by hydrogenation of carbon monoxide, which comprises cobalt and cerium oxide as catalytic components supported on a conventional porous material, or cobalt as a catalytic component and cerium oxide as a support thereof. This catalyst can produce C.sub.1 or more hydrocarbons and especially C.sub.5 or more hydrocarbons in good yields.

Abstract: A catalyst for decomposing an offensively smelling substance such as aldehydes by oxidation and a method which employs it for removing the offensively smelling substance. The catalyst comprises copper, cerium and silver supported on a porous ceramic carrier and is contacted with an offensively smelling substance to decompose it. The catalyst is particularly effective for decomposing aldehydes.

Abstract: Exhaust gas purifying method and apparatus for internal combustion engines in which the temperature of an exhaust gas purifying catalyst is detected and, as desired, oxygen content of exhaust gas is further detected, and in which the actual air-fuel ratio is varied toward the higher air-fuel ratio side and the lower air-fuel ratio side with respect to the theoretical air-fuel ratio, in accordance with the frequency and amplitude preset dependent on the kind of the catalyst and set based on these measured values.

Abstract: A thin film oxygen sensor with a microheater incorporates an oxide semiconductor and has an integral structure of a sensor portion and a heater portion, wherein a porous catalyst layer is formed on a surface of the sensor portion, and a thickness and an average pore diameter of the catalyst layer are determined such that a ratio of the thickness to the average pore diameter falls within a range of 50 to 3,000. The oxygen sensor has good reproducibility, high stability, and high sensitivity for changing a resistance in response to a change in an oxygen content in an atmosphere. The oxygen sensor can be manufactured at low cost and has a compact construction.

Abstract: A catalyst for the steam reforming of hydrocarbons into gases such as methane, hydrogen and carbon monoxide and a method of preparing the same. The catalyst which comprises cerium oxide and rhodium supported on a carrier can maintain high catalytic activity and durability for steam reforming without any carbon deposition on its surface.

Abstract: A catalyst for reducing nitrogen oxides, carbon monoxide and hydrocarbons, the noxious components in exhaust gases from internal combustion engines, etc., which comprises: a carrier having a substructure of refractory material in the form of a honeycomb structure, etc., and a porous layer of a powder formed on the surface thereof selected from the group consisting of a powder of zirconium oxide and a mixed powder of zirconium oxide powder with at least one powder selected from the group consisting of alumina, alumina-magnesia spinel and cerium oxide; and a catalyst ingredient supported thereon consisting of cerium oxide and a metal selected from the group consisting of platinum, palladium and mixtures thereof.