摘要:
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.
摘要:
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. The catalysts thereby obtained have improved stability, particularly when subjected to high temperatures, such as when they are used as post-combustion catalysts for exhaust gases from internal combustion engines, in which case metal A is platinum or palladium and metal B is platinum, palladium or rhodium, with the proviso that B is not the same as A.
摘要:
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.
摘要:
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.
摘要:
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).
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.