Patent DE-102008054691-A1 (DE)
Title: Catalyst composition, useful to produce a catalyst for exhaust gas treatment of internal combustion engine to reduce nitrogen content of exhaust gas, comprises a first metal, where e.g. rhodium, palladium and platinum are present
Inventor: SAFFE CHRISTOPH
IPC: B01J37/04
Filed: 2008-12-16
Abstract: Catalyst composition comprises at least a first metal (>= 1 wt.%, relative to the metal portion of the composition) as a catalytically active element, where: e.g. (a) the overall content of the metals rhodium (Rh), palladium (Pd), platinum (Pt), ruthenium (RU), iridium (Ir), rhenium (Re), osmium (Os), gold (Au) and silver (Ag) (not provided as the first metal) amounts to maximum of 200 ppm, preferably less than 100 ppm; and (c) the overall content of halogens and their compounds amounts to maximum 100 ppm, preferably less than 50 ppm. Catalyst composition comprises at least a first metal (>= 1 wt.%, relative to the metal portion of the composition) as a catalytically active element, where: (1) (a) the overall content of the metals rhodium (Rh), palladium (Pd), platinum (Pt), ruthenium (RU), iridium (Ir), rhenium (Re), osmium (Os), gold (Au) and silver (Ag) (not provided as the first metal) amounts to maximum of 200 ppm, preferably less than 100 ppm, relative to the metal content of the catalyst composition, and the content of: Rh, Pd and Pt is respectively 50 ppm, preferably together less than 30 ppm; Ru, Ir, Re, Os is respectively 40 ppm, preferably together less than 30 ppm; Rh, Pd, Pt is respectively 30 ppm, preferably together less than 30 ppm; (2) (b) the overall content of heavy metals iron (Fe), copper (Cu), nickel (Ni), cobalt (Co), chromium Cr(III), Cr(VI), mercury (Hg), lead (Pb), arsenic (As), indium (In), thallium (Tl), uranium (U), antimony (Sb), bismuth (Bi), gallium (Ga), germanium (Ge), manganese (Mn), zinc (Zn), tin (Sn), fluorine (F), vanadium (V), radioactive metals (not provided as the first metal) amounts to maximum 100 ppm, preferably less than 50 ppm, and the content of: Fe is 50 ppm, preferably less than 30 ppm; Cu is 50 ppm, preferably less than 10 ppm; Pb, Hg, Cr (III), Cr (VI), As is respectively 10 ppm, preferably together less than 10 ppm; Ni, Co is respectively 10 ppm, preferably together less than 5 ppm; In, Tl, U is respectively 10 ppm, preferably together less than 5 ppm; Sb, Bi, Ga, Ge is respectively 100 ppm, preferably together less than 20 ppm; Mn is 50 ppm, preferably less than 30 ppm; radioactive metal is an amount that corresponds to the radiation limit of 500 becquerels; (3) (c) the overall content of halogens and their compounds amounts to maximum 100 ppm, preferably less than 50 ppm, and the content of chlorine (Cl) is 50 ppm, preferably less than 30 ppm; F, bromine (Br), iodine (I) is respectively 50 ppm, preferably together 30 ppm; (4) (d) the overall content of the chalcogens other than oxygen and their compounds is maximum 1000 ppm, preferably less than 100 ppm, and the content of sulfur (S) is 100 ppm, preferably less than 50 ppm; selenium (Se), tellurium (Te), polonium (Po) is respectively 10 ppm, preferably together less than 5 ppm; (5) (e) the overall content of nitrogen group containing compounds is maximum of 2000 ppm, preferably less than 1000 ppm, and the content of nitrogen (N) is 1000 ppm, preferably less than 200 ppm; phosphorus (P) is 1000 ppm, preferably less than 50 ppm; and (6) (f) the concentration of carbon as an element or in the form of its compounds is maximum 11000 ppm, preferably less than 5000 ppm. An independent claim is also included for producing the catalyst composition, comprising mixing at least two material components with one another, where the mathematical product of each material components are calculated from its net weight, maximum production tolerances and maximum contamination with a predetermined first substance, then the sum of the product calculated for each material components are determined, the determined sum is dived by the sum of the net weight of the material components under the determination of a theoretical maximum contamination of the mixture with the first substance, and a comparison of the determined theoretical contamination with the first substance with a given maximum contamination with the first substance is made, when exceeding the given maximum contamination with the first substance a variation of the provided mixture of the at least two material components takes place.