Abstract: Compositions comprising a component containing (i) an acidic oxide support, (ii) an alkali metal and/or alkaline earth metal or mixtures thereof, (iii) a transition metal oxide having oxygen storage capability, and (iv) a transition metal selected from Groups Ib and/or IIb of the Periodic Table provide NOx control performance in FCC processes. The acidic oxide support preferably contains silica alumina. Ceria is the preferred oxygen storage oxide. Cu and Ag are preferred Group I/IIb transition metals. The compositions are especially useful in the cracking of hydrocarbon feedstocks having above average nitrogen content.

Abstract: The invention relates to a flue gas pipe (1) of an incineration plant, comprising a reaction zone (2) for breaking down harmful substances and a heat exchanger (3) for cooling the flue gas (R) which is mounted downstream and fitted with a dioxin catalytic converter (4). The dioxin catalytic converter (4) in the heat exchanger (3) makes it possible to prevent the renewed formation of dioxins by de novo synthesis when the temperature drops.

Abstract: A process for removal of carbon monoxide, hydrocarbons, and nitrogen oxides from the exhaust gas from lean-burn, diesel and other engines which produce exhaust gases containing excess oxygen is disclosed. An exhaust gas from an engine operating at an air-fuel ratio above about 18 is contacted with a multi-component catalyst having at least two catalytic components, each capable of reducing nitrogen oxides within a range of exhaust gas temperatures that is different from the range of exhaust gas temperatures within which each other component is capable of reducing nitrogen oxides. Oxidation of the remaining reducing gases is also accomplished. One example of a two catalytic component catalyst of this invention has a first component of Au supported on alumina, which reduces nitrogen oxides at exhaust gas temperatures between about 600° C. and 900° C., and a second component of Pt supported on Y-zeolite, which reduces nitrogen oxides at exhaust gas temperatures below 600° C.

Abstract: There are disclosed a process for purifying ammonia which comprises bringing crude ammonia into contact with a catalyst comprising manganese oxide as an effective ingredient to remove oxygen and/or carbon dioxide that are contained as impurities in the ammonia, and a process for purifying ammonia which comprises bringing crude ammonia into contact with a catalyst comprising manganese oxide as an effective ingredient, and thereafter with a synthetic zeolite having a pore diameter in the range of 4 to 10 Å to remove at least one impurity selected from the group consisting of oxygen, carbon dioxide and moisture that are contained in the crude ammonia. It is made possible by the above process to remove impurities to an extremely low concentration from crude ammonia available on the market for industrial use and crude ammonia from a gallium nitride compound semi- conductor without decomposition of ammonia to generate hydrogen.

Abstract: The present invention provides a technique of reducing the concentration of carbon monoxide included in a hydrogen rich gas, which is fed as a supply of gaseous fuel to fuel cells. It is required that the activity of a carbon monoxide selective oxidation reaction for reducing the concentration of carbon monoxide is kept at a sufficiently high level in a wider temperature range. A CO selective oxidation unit 34, which reduces the concentration of carbon monoxide included in a hydrogen rich gas fed to fuel cells 20, has a carbon monoxide selective oxidation catalyst that includes a second element, such as lithium, in addition to ruthenium as a primary component. This arrangement enables the activity of the carbon monoxide selective oxidation reaction in the CO selective oxidation unit 34 to be kept at a sufficiently high level in a wider temperature range.

Abstract: Method and apparatus for treating the atmosphere to lower the concentration of pollutants therein in which ambient air is passed into operative contact with a stationary substrate having at least one ambient air contacting surface having a pollutant treating material thereon.

Abstract: Mono- and bimetallic transition metal carbides, nitrides and borides, and their oxygen containing analogs (e.g. oxycarbides) for use as water gas shift catalysts are described. In a preferred embodiment, the catalysts have the general formula of M1AM2BZCOD, wherein M1 is selected from the group consisting of Mo, W, and combinations thereof; M2 is selected from the group consisting of Fe, Ni, Cu, Co, and combinations thereof; Z is selected from the group consisting of carbon, nitrogen, boron, and combinations thereof; A is an integer; B is 0 or an integer greater than 0; C is an integer; 0 is oxygen; and D is 0 or an integer greater than 0. The catalysts exhibit good reactivity, stability, and sulfur tolerance, as compared to conventional water shift gas catalysts. These catalysts hold promise for use in conjunction with proton exchange membrane fuel cell powered systems.

Abstract: The present invention provides a catalyst selectively oxidizing carbon monoxide in a mixed gas comprising carbon monoxide and hydrogen as well as a catalyst selectively oxidizing hydrogen. A catalyst selectively oxidizing carbon monoxide is obtained by dispersing platinum black on a surface of a base metal compound oxide including Co2O3, MnO2, CuO, and Cr2O3, and forming an Ag2O layer on the platinum black layer. The catalyst selectively oxidizing hydrogen in a mixed gas comprising carbon monoxide and hydrogen is obtained by dispersing Ag2O on a surface of said base metal compound oxide and further forming a platinum black layer on the Ag2O layer. In addition the present invention provides a contact combustion carbon monoxide sensor not having the sensitivity to hydrogen as well as that not having the sensitivity to carbon monoxide.

Abstract: A catalyst for the full oxidation of volatile organic compounds (VOC), particularly hydrocarbons, and of CO to CO2, which comprises a compound having the formula A2B3O6±d where A is an alkaline-earth metal, an alkaline metal, a lanthanide, or a solid solution thereof, B is a transition metal, an element of group III, or a solid solution thereof, and d has a value between 0 and 1; and a method for the full oxidation of volatile organic compounds using the catalyst.

Abstract: Disclosed are a gas purification-treating agent and a gas purifying apparatus, which treat carbon monoxide and/or hydrogen contained in a gas in the presence of oxygen. The gas purification-treating agent consists of an adsorbent having carbon dioxide and/or water adsorptivity, and a metal or metal compound which is carried on the adsorbent and activates oxidation reaction of carbon monoxide and/or hydrogen. The gas purifying apparatus has the gas purification-treating agent contained in a container having a gas inlet and a gas outlet. The adsorbent adsorbs carbon dioxide and/or water contained originally in the gas, as well as, carbon dioxide and/or water to be formed by the oxidation reaction of carbon monoxide and/or hydrogen. The metal or metal compound is at least one selected from Au-on-metal oxides, Au-on-metal hydroxides and an Au colloidal powder, or palladium and/or platinum.

Abstract: A composition for abatement of airborne pollution by volatile organic compounds (“VOCs”) has an upstream composition which contains a protective adsorbent, e.g., Y zeolite, which is effective for adsorbing large VOC molecules, e.g., toluene, and a protective oxidation catalyst intimately intermingled therewith. The downstream composition contains a second adsorbent, e.g., a silver-containing ZSM-5, which is effective for adsorbing relatively smaller VOC molecules, e.g., propylene, and a second oxidation catalyst intimately intermingled therewith. Oxidation of VOCs while they are still retained on the adsorbents is promoted at temperatures lower than would be required if the VOCs were desorbed into the gaseous phase. Apparatus is provided including a first contact member (24) coated with the upstream composition and positioned upstream of a second contact member (32) coated with the downstream composition.

Abstract: A combustion catalyst comprising a monolithic substrate, a porous support based on refractory inorganic oxide and an active phase formed by cerium, iron and at least one metal selected from the group formed by palladium and platinum, the content of porous support being between 100 and 400 g per liter of catalyst; the content of cerium being between 0.3 and 20% by weight with respect to the porous support; the content of iron being between 0.01 and 3.5 % of iron by weight with respect to the porous support; and the content of palladium and/or platinum being between 3 and 20 g per liter of catalyst.

Abstract: An iron compound catalyst for inhibiting the generation of dioxin of the present invention, comprise iron oxide particles, iron oxide hydroxide particles or mixed particles thereof having a catalytic activity capable of converting not less than 15% of carbon monoxide into carbon dioxide when 2.8×10−4 mol of iron oxide particles obtained by heat-treating said iron compound catalyst in air at a temperature of 800° C. for 15 minutes, are instantaneously contacted with 6.1×10−7 mol of carbon monoxide at a temperature of 250° C. at a space velocity (SV) of 42,400 h−1 in an inert gas atmosphere using a pulse catalytic reactor, said iron oxide particles or said iron oxide hydroxide particles having an average particle size of 0.01 to 2.0 &mgr;m, a BET specific surface area of 0.2 to 200 m2/g, a phosphorus content of not more than 0.02% by weight, a sulfur content of not more than 0.6% by weight and a sodium content of not more than 0.5% by weight.

Abstract: Disclosed is a hydrogen generation process for use with fuel cells which includes a preferential oxidation step to reduce the concentration of carbon monoxide. The preferential oxidation step includes contacting a fuel stream comprising hydrogen and carbon monoxide in the presence of an oxygen at a preferential oxidation temperature of between about 70° and about 160° C. with preferential oxidation catalyst for reducing the concentration of carbon monoxide to produce a treated fuel gas stream comprising less than about 50 ppm-vol carbon monoxide. The preferential oxidation catalyst comprises ruthenium metal disposed on an alumina carrier having a low density and a high porosity. Superior performance at low preferential oxidation temperatures below 130° C. was observed when the alumina carrier contained a bimodal pore distribution with an average pore distribution of from about 20 to about 3000 angstroms.

Abstract: A catalyst for treating exhaust gas from an internal combustion engine includes a carrier body coated with an inner layer and an outer layer. The inner layer includes platinum deposited on a first support material and on a first oxygen storage component, and the outer layer includes platinum and rhodium deposited on a second support material and on a second oxygen storage component. The first and second support materials may be the same or different, and may be selected from the group of: silica, alumina, titania, zirconia, mixed oxides or mixtures thereof, and zirconia-rich zirconia/ceria mixed oxide. The first and second oxygen storage components may include ceria-rich ceria/zirconia mixed oxide compounds, optionally including praseodymia, yttria, neodymia, lanthana or mixtures thereof.

Abstract: In a method and apparatus for selective catalytic oxidation of carbon monoxide, the gas mixture and an additionally added oxidizing gas are conducted through a reactor containing the catalyst. Oxidizing gas is added at several points along the mixed gas flow path with a controlled or regulated through flow volume. The mixed gas stream is cooled passively by static mixing structures located in the inlet area of the CO-oxidation reactor. By controlling exothermal CO oxidation along the reactor path, a very variable process guidance is provided, that can be adjusted to individual situations.

Abstract: Nitrogen oxides are removed from an exhaust gas containing nitrogen oxides and oxygen in a proportion larger than its stoichiometric proportion relative to unburned components in the exhaust gas, by (i) disposing an exhaust gas cleaner in a flow path, the exhaust gas cleaner comprising a first catalyst composed of 0.2-20 parts by weight (on a metal basis) of silver or silver oxide supported on a porous inorganic oxide, and a second catalyst composed of 1-50 parts by weight (on an oxide basis) of tungsten and/or vanadium supported on a porous inorganic oxide; (ii) introducing oxygen-containing organic compounds having 2 or more carbon atoms or a fuel containing the oxygen-containing organic compounds into the exhaust gas on the upstream side of the exhaust gas cleaner; and (iii) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 150-650° C., thereby causing a reaction of the nitrogen oxides with the oxygen-containing organic compounds to remove the nitrogen oxides.

Abstract: Compositions comprising a component containing (i) an acidic oxide support, (ii) an alkali metal and/or alkaline earth metal or mixtures thereof, (iii) a transition metal oxide having oxygen storage capability, and (iv) a transition metal selected from Groups Ib and/or IIb of the Periodic Table provide NOx control performance in FCC processes. The acidic oxide support preferably contains silica alumina. Ceria is the preferred oxygen storage oxide. Cu and Ag are preferred Group I/IIb transition metals. The compositions are especially useful in the cracking of hydrocarbon feedstocks having above average nitrogen content.

Abstract: An exhaust-gas-purifying catalyst is made by depositing on a support iridium serving as a catalyst active substance, sulfur for improving the catalyst activity of iridium and, if necessary, platinum. The sulfur is preferably contained as a sulfate. The exhaust-gas-purifying process of the present invention is a process in which exhaust gas from an internal combustion engine is allowed to pass through the exhaust-gas-purifying catalyst with the exhaust-gas temperature being set in the range of 200° C. to 700° C. at the inlet of the exhaust-gas-purifying catalyst. The above-mentioned composition and process provide an activity for purifying exhaust gas, especially for eliminating nitrogen oxides in an oxidizing atmosphere, in a wide temperature range, allow high heat-resistance and durability, and consequently, are superior in practical use.

Abstract: A system for generating a high-hydrogen gas comprises a reformer for the catalytic water vapor reforming of a water vapor/fuel mixture while supplying thermal energy; a gas purification stage for removing carbon monoxide from the high-hydrogen gas while releasing heat; and devices for transmitting thermal energy from the gas purification stage into the reformer. The reaction rates in the reformer and in the gas purification stage are designed such that a defined temperature level is set automatically by the coupling of the two reactions.

Abstract: A multistage device for the selective catalytic oxidation of carbon monoxide contained in a hydrogen-rich gas-mixture stream includes at least three stages, each stage having at least one CO oxidation chamber. An oxidizing medium may be metered to an inlet side of each stage. A common cooling device is provided for the first two stages and an independent cooling device is provided for the third stage.

Abstract: There are disclosed a process for effectively reducing a carbon monoxide concentration in a hydrogen-containing gas obtained by reforming methanol or the like, and a catalyst used therefor. In the present invention, carbon monoxide in the hydrogen-containing gas is contacted with oxygen in the presence of a catalyst comprising platinum and at least one metal selected from the group consisting of cobalt, nickel, copper and manganese.

Abstract: Systems and apparatus for catalytically oxidizing organic matter, particularly the incomplete combustion products of carbon-containing fuels such as fossil fuels. The systems and apparatus utilize catalytically reactive particles that are suspended by moving air within a reaction chamber and maintained at a temperature sufficient to cause the suspended media particles, typically silica sand, silica gel, or alumina, to become catalytically reactive in the presence of moisture. Typically, the reaction chamber is maintained at a temperature in a range from about 100° C. to about 500° C. Moisture may be provided by the waste exhaust, although additional moisture may be introduced into the reaction chamber in order to maintain reactivity of the catalytically reactive particles. The systems and apparatus can be adapted to be used in combination with diesel engines or other internal combustion engines and industrial burners.

Abstract: An apparatus for extracting a gas, in particular hydrogen, from a fluid stream utilizing a plate membrane flattened with a wave spring on the low pressure side of the membrane and a turbulence generator on the high pressure side. Alternately, the membrane is folded and wrapped against a central conduit within the membrane fold. Extraction membranes have a substrate layer of Ta—W, V—Co, V—Pd, V—Au, V—Cu, V—Al, Nb—Ag, Nb—Au, Nb—Pt, Nb—Pd, V—Ni—Co, V—Ni—Pd, V—Nb—Pt or V—Pd—Au alloy or combination thereof and a first layer affixed to the outer surface of the substrate towards a mixed gas flow which is composed of palladium, platinum, rhodium, or palladium alloys.

Abstract: Super clean air having therein chemical components—such as hydrocarbons, organic halogens, acidic gases, basic gases, aldehydes, nitrogen oxides, and H2O (that is, all components other than oxygen, nitrogen, and noble gases—the types of chemical components differ depending on the source of the air)—in concentrations no more than 1 ppb and a dew point lower than −40° C., is obtained from the atmosphere by low-temperature adsorption treatment in stages at temperatures ranging from −40° C. to −180° C. Material air collected from the atmosphere is pretreated in a room-temperature adsorption step to remove moisture and carbon dioxide. The pretreated air is then low-temperature adsorption treated by absorbents in a plurality of steps to adsorb the gaseous chemical components, the treatment temperature being lower in each succeeding step. Treatment at −40° C. may remove, for example, HF, SO2, and/or NH3. Treatment at −100° C.

Abstract: A process and catalyst for the conversion of contaminants in an oxygen containing contaminated stream comprises passing the oxygen containing contaminated stream over a photocatalyst comprising titanium, zirconium and silica while irradiating the foregoing catalyst with ultraviolet light.

Abstract: Method and apparatus for treating the atmosphere to lower the concentration of pollutants therein in which ambient air is passed into operative contact with a stationary substrate having at least one ambient air contacting surface having a pollutant treating material thereon.

Abstract: An assembly, a method and a motor vehicle for cleaning ambient air in the vicinity of an internal combustion engine (102) having combustion air inlet means (103) and energy emitting means (104)are disclosed. The assembly (101) further includes adsorbent means (105) for adsorbing at least one pollutant when in a first mode of operation and for desorbing the pollutant when in a second mode of operation. The adsorbent means have an inlet (106) for polluted ambient air (107, 107′) and an outlet (108) for cleaned ambient air (109, 109′). Furthermore, the assembly (101) includes a pollutant conduit (110) through which the desorbed pollutant is transferred from the adsorbent means (105) to the combustion air inlet means (103) when in the second mode of operation, and the adsorbent means (105) are arranged for being brought into the second mode of operation by means of energy supplied from the energy emitting means (104).

Abstract: A process for removing carbon dioxide from a gas stream containing hydrogen, carbon monoxide and carbon dioxide comprising subjecting the gas stream to a first stage high-temperature selective catalytic methanation to lower the carbon monoxide concentration in the gas but not below a concentration which allows carbon dioxide methanation to take place, followed by a second stage low selective catalytic methanation to lower the residual carbon monoxide in the gas stream to a concentration of below 40 ppm. The high temperature methanation is suitably carried out at a temperature of between 250° C. and 350° C., and the low temperature methanation is suitably carried out at a temperature below 270° C.

Abstract: An integrated process for vent gas treatment for the abatement of volatile emissions is disclosed. The vent gas comprises dioxygen, carbon monoxide, hydrocarbons and other organic compounds comprising one or more alkyl halide compound of 1 to 5 carbon atoms. In the preferred embodiment, the vent gas is heated and mixed with an amount of combustible fluid. Then the mixture is directed to a catalytic oxidation reactor having a suitable oxidation catalyst disposed therein, wherein the mixture is catalytically oxidized. The effluent from the catalytic oxidation reactor is directed to heat the incoming vent gas and subsequently to a scrubber wherein the effluent is scrubbed of soluble compounds and the resultant treated gas stream is vented. Importantly, the amount of combustible fluid supplied to the vent gas stream is controlled so at to provide sufficient reactants for the catalytic oxidation to maintain reaction temperatures from 200° C. and 600° C.

Abstract: Method and apparatus for treating the atmosphere to lower the concentration of pollutants therein in which ambient air is passed into operative contact with a stationary substrate such as an automobile at rest, a billboard, an air conditioning unit, a transportation tunnel and the like, the stationary substrate having at least one ambient air contacting surface having a pollutant treating composition thereon.

Abstract: Method for treating atmospheric pollutants by contacting the atmosphere with a catalyst composition or adsorptive material coated on the surface of a substrate in which the catalyst composition or adsorptive material is protected from degradation by harmful contaminants contained in the atmosphere by a coating of at least one porous protective material and a device useful therefor.

Abstract: A process of operating a nitrogen oxides storage catalyst of an exhaust gas treatment system is described. The process relates to the cycling of the normalized air/fuel ratio &lgr;-value of the exhaust gas exiting the engine, in which a lambda value greater than 1 represents oxygen-rich, lean burn conditions in which a sorption phase for the sorption of nitrogen oxides takes place; and in which a lambda value less than 1 represents oxygen-poor, rich burn conditions in which a desorption and conversion phase for the desorption and conversion of nitrogen oxides takes place. The &lgr;-value of the exhaust gas downstream from the storage catalyst is monitored during the desorption and conversion phase to determine the end of the desorption and conversion phase based on the &lgr;-value falling below a predetermined threshold value.

Abstract: We have recently proposed special catalysts, Pt-supported zeolites, for the selective oxidation of carbon monoxide in reformed fuels from methanol or natural gas. They can be applied to polymer electrolyte fuel cells, of which Pt anode catalysts suffer serious poisoning by the trace amount of CO. In order to enhance the performance of the catalysts, the selective CO oxidation was examined over Pt—, Ru—, Pd—, Co—, and PtRu— supported zeolites in a large excess of H2 with the addition of a low concentration of oxygen. It was found that Pt, Ru, and PtRu supported on mordenite can oxidize CO much more selectively than a conventional Pt-supported alumina catalyst. Ru/mordenite showed the highest selectivity of approximately 100% at 200° C. with a certain flow rate of the reactant. Pt-Ru/mordenite exhibited fairly high selectivity of 90% over a wide flow rate condition even at 150° C.

Abstract: There is provided a method and apparatus for treatment of a hydrogen-rich gas to reduce the carbon monoxide content thereof by reacting the carbon monoxide in the gas with an amount of oxygen sufficient to oxidize at least a portion of the carbon monoxide in the presence of a catalyst in a desired temperature range without substantial reaction of hydrogen. The catalyst is an iridium-based catalyst dispersed on, and supported on, a carrier. In the presence of the catalyst, carbon monoxide in a hydrogen-rich feed gas is selectively oxidized such that a product stream is produced with a very low carbon monoxide content.

Abstract: A catalytic composition and method of making the same in which a catalytic material has an average pore size distribution sufficiently large to substantially prevent capillary condensation.

Abstract: Thermal catalysts, particularly catalysts coated with precious metals, are used to reduce the concentration of CO, HC and NOx in exhaust gases from internal-combustion engines. While catalysts coated with precious metals exhibit catalytic activity from about 140.degree. C., to ensure very low emission levels thermal catalysts need to be heated during cold starting so that the pollutants produced during the cold start react. The specification discloses a catalyst with a photocatalytic semiconductor illuminated with UV light for this purpose. Suitable for use as the photocatalytic material is e.g. titanium dioxide. This enables pollutant levels to be reduced immediately after the engine has been started and even at relatively low ambient temperatures. The invention is suitable for use with diesel engines and lean-mixture spark-ignition engines.

Abstract: Oxidation catalyst compositions include a catalytic material having a BET surface area of at least about 10 m.sup.2 /g and consists of a combination of bulk ceria and a bulk second metal oxide which may be one or more of titania, zirconia, ceria-zirconia, silica, alumina-silica and .alpha.-alumina. The combination may optionally also include activated alumina having a BET surface area of at least about 10 m.sup.2 /g. The ceria, second metal oxide and optional activated alumina may be mixed together or provided as discrete layers. Optionally, one of platinum or palladium metal may be dispersed on the catalytic material provided that the platinum, when used, is used in limited amounts to preclude excessive oxidation of SO.sub.2 to SO.sub.3. The catalyst compositions may be used for oxidation of oxidizeable components in a gas-borne stream, e.g., in a method to treat diesel engine exhaust by contacting the hot exhaust with the catalyst composition to promote the oxidation of the volatile organic fraction.

Abstract: Mixed oxides excellent in thermal stability of specific surface area and in oxidation-reduction performance are provided on an industrial scale. Catalyst materials useful in exhaust gas purification are also provided. The invention is concerned with mixed oxides containing cerium, zirconium and sulfur, namely cerium- and zirconium-based mixed oxides having the composition: 50 to 79% by weight as cerium oxide, 20 to 49% by weight as zirconium oxide, and 1 to 5% by weight as sulfate (SO.sub.4). The invention also relates to a method of producing cerium- and zirconium-based mixed oxides which comprises mixing a cerous-alkali metal sulfate double salt with a zirconium ion-containing solution and then adding a base to the mixed solution to thereby cause formation of a precipitate. The invention further relates to catalyst materials for exhaust gas purification which comprise a mixed oxide containing cerium, zirconium and sulfur, namely a cerium- and zirconium-based mixed oxide containing sulfur in an amount of 0.

Abstract: Compositions comprising a component containing (i) an acidic oxide support, (ii) an alkali metal and/or alkaline earth metal or mixtures thereof, (iii) a transition metal oxide having oxygen storage capability, and (iv) a transition metal selected from Groups Ib and/or IIb of the Periodic Table provide NO.sub.x control performance in FCC processes. The acidic oxide support preferably contains silica alumina. Ceria is the preferred oxygen storage oxide. Cu and Ag are preferred Group I/IIIb transition metals. The compositions are especially useful in the cracking of hydrocarbon feedstocks having above average nitrogen content.

Abstract: The invention is a method for treating exhaust gas containing carbon monoxide, hydrocarbons, and nitrogen oxides generated by a lean burn internal combustion engine. It includes bringing the exhaust gas into contact with a particular metal-zirconium oxide material made by sol-gel processing and which includes at least 0.1 wt. % precious metal. The alkoxides include heterometallic alkoxides containing zirconium and alkali metal or alkaline earth metal. Optionally the oxide may contain a lanthanide metal. Under lean-burn conditions nitrogen oxides are absorbed on the oxide and when the oxygen concentration is lowered the absorbed nitrogen oxide are desorbed and reduced over the precious metal.

Abstract: Compositions comprising a component containing (i) an acidic oxide support, (ii) an alkali metal and/or alkaline earth metal or mixtures thereof, (iii) a transition metal oxide having oxygen storage capability, and (iv) a transition metal selected from Groups Ib and/or IIb of the Periodic Table provide NO.sub.x control performance in FCC processes. The acidic oxide support preferably contains silica alumina. Ceria is the preferred oxygen storage oxide. Cu and Ag are preferred Group I/IIb transition metals. The compositions are especially useful in the cracking of hydrocarbon feedstocks having above average nitrogen content.

Abstract: A process for purifying argon to obtain a high-purity argon from argon gas containing at least nitrogen, carbon monoxide, oxygen, and methane, including a first step of adding air or oxygen to the argon gas in an amount sufficient to oxidize the contained carbon monoxide into carbon dioxide in the presence of a catalyst while maintaining a temperature sufficient to oxidize the contained carbon monoxide without substantially oxidizing the methane, a second step of adding hydrogen into the argon gas obtained in the first step and reacting the contained oxygen with the hydrogen into water in the presence of a catalyst, a third step of removing the carbon dioxide and the water from the argon gas obtained in the second step by use of an adsorbent, and a fourth step of cooling the argon gas obtained in the third step, introducing the argon thus cooled into a distillation column and performing distillation by use of a reflux containing argon as a main component to remove nitrogen, hydrogen, and methane, thereby reco

Abstract: An argon gas stream containing hydrogen, carbon monoxide, water vapor, oxygen carbon dioxide, nitrogen and methane is purified by drying the gas stream with a desiccant, oxidizing the hydrogen and carbon dioxide to water vapor and carbon dioxide by contact with oxidizing catalysts in the presence of excess oxygen, removing the water vapor and carbon dioxide from the gas stream by adsorption, removing excess oxygen by chemisorption at elevated temperature and removing the nitrogen and methane by adsorption at cryogenic temperature. Alternatively, excess oxygen is removed from the gas stream by adsorption at a cryogenic temperature.

Abstract: A method is provided for treating diesel engine exhaust gas with a catalyst containing a physical mixture of particles. The catalyst contains a physical mixture of particles of (i) a bi-metal oxide of manganese and zirconium and (ii) a precious metal, such as platinum, supported on an alumina, such as gamma alumina.

Abstract: A ZnO--Pd composite catalyst wherein Pd is dispersed and fixed on the surface of ZnO is produced by ion adsorption process having the steps of soaking ZnO in an acid solution of Pd to adsorb Pd ions (Pd.sup.2+) onto the surface of ZnO; and reducing the adsorbed Pd ions to metallic Pd particles so that the metallic Pd particles are substantially evenly deposited on the surface of ZnO. The ZnO--Pd composite catalyst provides a stable and continuing CO oxidizing capability, without light irradiation, even when the air to be treated contains sulfur compounds such as H.sub.2 S and SOx.

Abstract: Process for purifying a gas flow with respect to at least one of the impurities capable of being oxidized and/or reduced which it contains, in which the gas flow is subjected to at least the following steps:(a) compressing the gas flow to a pressure in excess of atmospheric pressure,(b) bringing the compressed gas flow into contact with at least a first bed of particles of a material containing at least one metal peroxide, and(c) bringing the gas flow resulting from step (b) into contact with at least a second bed of at least one catalyst.

Abstract: A process for decreasing the air-sensitivity of a carbon monoxide oxidation catalyst composition is provided. The process can comprise, consist essentially of, or consist of (1) heating the composition at a temperature sufficient to produce an activated composition; (2) contacting the activated composition with an oxygen-containing fluid whereby a deactivated composition is produced; and (3) contacting the deactivated composition under reducing atmosphere and at a low temperature wherein the composition can comprise, consist essentially of, or consist of platinum, iron, and an inorganic support; or can comprise, consist essentially of, or consist of palladium, platinum, iron, and an inorganic support.

Abstract: Carbon dioxide, water, carbon monoxide and hydrogen are removed from a gas stream such as air or nitrogen by adsorbing water and carbon dioxide on a solid absorbent of alumina, or zeolite and oxiding carbon monoxide over a solid catalyst to carbon dioxide and adsorbing the resulting carbon dioxide and chemisorbing the hydrogen on the catalyst, which may be palladium on alumina.

Abstract: A catalyst for use in catalysing the oxidation of carbon monoxide and hydrocarbons which comprises an oxide support having captured thereon a noble metal in catalytically effective form. The catalyst is characterised by the presence of an oxide of titanium, molybdenum of a mixture thereof.