Abstract: A method for preparing multi-metal catalysts including an active phase consisting of at least two metals, A and B, which are selected from groups VIII and IB of the periodic table, and a porous support. According to the method: firstly, at least a part of the porous support is impregnated with at least one precursor of metal A; secondly, activation is performed in a neutral or oxidizing atmosphere at a temperature of 120.degree.-800.degree. C. whereafter a treatment is carried out in a reduction medium at a temperature of 0.degree.-800.degree. C.; thirdly, at least a part of the support which was previously impregnated with the precursor of metal A is impregnated with at least one precursor of metal B; and fourthly, activation is performed in a neutral or oxidizing atmosphere at a temperature of 120.degree.-800.degree. C.

Abstract: Exhaust manifold for catalytic treatment of the exhaust gases of an internal-combustion engine comprising a metallic outer tube (1) including a catalyst layer (4) in direct contact with the exhaust gases. According to the invention, the manifold also comprises at least one inner tubular element (2), substantially coaxial to said outer tube (1) and providing with the latter at least one space (3), the inner surface of said inner tube (2) being coated by said catalyst layer (4).

Abstract: Multiple purpose catalysts adapted for the treatment of internal combustion engine exhaust gases comprise a particulate refractory oxide support, e.g., alumina particles, having an active catalytic phase deposited thereon, said active catalytic phase including zirconium, cerium and platinum, and optionally iridium, rhodium, palladium and other metal values.

Abstract: Multiple purpose catalysts adapted for the treatment of internal combustion engine exhaust gases comprise a particulate refractory oxide support, e.g., alumina particles, having an active catalytic phase deposited thereon, said active catalytic phase including zirconium, cerium and platinum, and optionally iridium, rhodium, palladium and other metal values.

Abstract: A multifunctional catalyst, a method of preparing the catalyst and the use of the catalyst in treating exhaust fumes from internal combustion engines are described. The catalyst includes a porous layer containing (weight %, dry):about 50 to about 99.7% of at least one refractory inorganic oxide,about 0.1 to about 25% of at least one uranium oxide,about 0.1 to about 35% of at least one oxide of at least one metal P selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, lanthanum, praseodymium, neodymium, gadolinium, and yttrium andabout 0.1 to 20% of a metal A selected from the group consisting of platinum, rhodium, palladium, ruthenium, iridium, and mixtures thereof.

Abstract: Thermally stable, sulfur-resistant catalysts for the conversion of exhaust gases from internal combustion engines includes an inert, rigid support substrate, e.g., a cellular monolith, coated with a layer of porouse material, the porous material containing alumina, at least one rare earth oxide, and a spinel type compound having a specific surface of at least 50 m.sup.2 /g, and the support substrate having an effective amount of a catalytically active phase impregnated onto the porous coating thereof.

Abstract: Improvedly time-stable catalysts adopted for the treatment of internal combustion engine exhaust gases include a monolithic catalyst support impregnated with a plurality of catalytically active phases, one section of the support being impregnated with a first catalytically active phase and remaining section of the support being impregnated with a second catalytically active phase.

Abstract: A multifunctional pollution control catalyst for the treatment of exhaust gases from internal combustion engines is comprised of a catalyst support having an active catalytic phase deposited thereon, said active catalytic phase comprising catalytically effective amounts of (i) zirconium, (ii) cerium, (iii) palladium, (iv) iridium and/or rhodium, and, optionally, (v) iron.

Abstract: A composite active phase/support catalyst adapted for the treatment of internal combustion engine exhaust gases, the active phase of which comprising at least one metal from a first group comprising platinum, palladium, iridium, rhodium, ruthenium, rhenium, silver, gold or plurality thereof and at least one additional metal and the support therefor comprising binder/filler admixture, is facilely prepared by (i) intimately admixing the binder and filler support material with at least 50% by weight but less than all of said at least one first group metal, or precursor thereof, and/or of said at least one additional metal, (ii) forming the resulting admixture into catalyst shaped article, (iii) drying and optionally calcining said catalyst shaped article, (iv) incorporating the remainder of said at least one first group metal, or precursor thereof, and/or said at least one additional metal into said catalyst shaped article, and then (v) drying and activating the composite catalyst.

Abstract: A pollution control catalyst for a catalytic converter in the exhaust system of an internal combustion engine, which catalyst comprises a support impregnated with (i) at least one platinum group precious metal, and with (ii) cerium base metal, or a combination of cerium and at least one other base metal, is facilely prepared by (1) impregnating a catalyst support with precursor compounds of said cerium base metal, or of said cerium base metal and of at least one other base metal, (2) activating said impregnated support, under a neutral or oxidizing atmosphere, at a temperature ranging from 120.degree. to 800.degree. C.

Abstract: Provided is an improved catalyst and a process employing same in the treatment of exhaust gases generated by internal combustion engines. The catalyst comprises a support and an active phase comprising copper, cerium and/or iron, at least one metal selected from the group consisting of platinum and palladium, and at least one metal selected from the group consisting of iridium and rhodium. The catalyst is particularly active in the removal of carbon monoxide, unburned hydrocarbons and nitrogen oxides generally present in the exhaust gases of an internal combustion engine.

Abstract: A pollution control catalyst for a catalytic converter within the exhaust system of an internal combustion engine is facilely prepared by (i) coating/impregnating a catalyst support with palladium and at least one base metal catalyst, (ii) activating the step (i) catalyst, (iii) next coating/impregnating the step (ii) activated catalyst with at least one platinum group precious metal other than palladium, or combination of palladium and at least one other platinum group precious metal, and (iv) then activating the step (iii) catalyst.

Abstract: An elongate catalytic muffler of the radial flow type for purifying the exhaust gases of an internal combustion engine, comprises a tubular casing having a gas inlet at one end and a gas outlet at the other end. Two co-axial substantially parallel frustra-conical grids of decreasing cross-section from the inlet end to the outlet end of the muffler define, with cup-like end walls, a catalyst chamber compression means is provided for axially displacing one of said end walls towards the other, so as to compress the catalyst mass in said chamber, and with said compression means being protected by tight separating means from the action of the exhaust gases treated in the muffler.

Abstract: The exhaust gases from internal combustion engines are catalytically oxidized/reduced, to remove CO, unburned hydrocarbons and NO.sub.x therefrom, utilizing an improved stable and long-lived catalyst which comprises (1) a support substrate, e.g., a monolithic or particulate support, and (2) an active phase deposited thereon, said active phase (2) comprising (i) cerium, (ii) iron, (iii) at least one of the metals gallium and/or yttrium, (iv) at least one of the metals platinum and/or palladium, and (v) at least one of the metals iridium and/or rhodium.

Abstract: A pollution control catalyst for a catalytic converter comprising the exhaust system of an internal combustion engine, said catalyst including a refractory oxide support, and an activated phase therefor comprised of 0.3 to 7% by weight cerium based upon the weight of said support, 0.1 to 3.5% by weight iron, also based upon the weight of said support, at least one platinum or palladium metal, and at least one iridium or rhodium metal.

Abstract: A low polarization electrode which is stable and safe to use, is manufactured by forming a layer of divided nickel or nickel alloy on an electricity-conducting substrate and thereafter sulfiding the surface of the resultant material. For example, a Raney nickel alloy is deposited on the substrate, the alloy metal is removed and the resultant material is sulfided.