Catalyst body for purifying exhaust gas

[Detailed Description of the Invention]

Field of the Invention The present invention is a kerosene fan heater, exhaust gas for cars, and home burning appliances, for example, an oilstove, and Chee 2 Behn. It is related with the catalyst body which purifies exhaust gas, such as carbon monoxide l and hydrocarbon generated from apparatus, such as a pull roaster 1 electrical oven, and nitrogen oxide. The composition and its problem of a conventional example Although various kinds of things are known as this kind of a catalyst body, What combined metal oxide catalysts, such as manganese dioxide, with Al Min acid lime, Things which use Al Min acid lime for a binding material, such as what supported the platinum group metal catalyst to the carrier which combined titanium oxide etc. with Al Min acid lime, Since things of high specific surface area, such as the shape of Nonicom, could be fabricated easily and moreover were not sintered, specific surface area is large, and it has the feature outstanding as a catalyst. However, when it is used by high temperature, it has a problem to which Yo Si and catalyst ability deteriorate in reduction of the specific surface area by a sinter ring. The object of an invention An object of the present invention is to improve the heat resistance of the catalyst body which uses Al Min acid lime for a binding material. Constitution of an invention a carrier which contains Al Min acid lime and Magnee 3 pay Desia cement at least in the present invention -- platinoid elements and It's a rare earth element. -- Si -- at least one sort of catalysts chosen from a group were made to support Therefore, a Good-bye ring is decreased to addition of magnesia cement, and heat resistance is improved. It is preferred here for titanium oxide and a zirconium dioxide to be independent, or to add both in a carrier. Binding materials of a catalyst carrier used by the present invention are Al Min acid lime (alumina cement) and magnesia cement. Generally, Al Min acid lime is denoted by mAR203 and ncao, and magnesia cement is denoted by mMgO-n Mg G 122. Al Min acid lime can be called desirable cement from a viewpoint of catalyst manufacture from heat resistance being also high, and mechanical strength being also large, and a cure rate being quick. On the other hand, mechanical strength is small cement although magnesia cement is excellent in the Al Min It's acid lime. Si heat resistance. If lime comes [ Al Min acid lime ] on 400 % of the weight, heat resistance will become small and, especially as for the mechanical strength of a carrier, A dog gets drunk will cause heat destruction. On the other hand, if there is little lime, heat resistance will improve, but while mechanical strength falls, Si with long care-of-health time at the time of fabrication and productivity also worsen. If the amount of alumina still becomes below 35 weight charge, heat resistance will fall, and if the amount of alumina increases, heat resistance will improve. Especially the desirable composition especially of Al Min acid lime of 20~40 % of the weight and 36~85 % of the weight of alumina parts is [ 15~50 % of the weight of lime ] 30~60 % of the weight. The Al Min acid lime content of a carrier is needed at least 355% of the weight from the relation of mechanical strength. Desirable % content of magnesia cement in a catalyst carrier is below 1o weight. If it exceeds 100% of the weight, while fast curing will increase extremely and productivity will worsen, rapidly large Sports-proof [ Si ] ring nature falls [ a thermal expansion coefficient ] very much. Mechanical strength also falls. As a particle size of magnesia cement, 40 microns or less are [ below 8o micron desirable ] the optimal. 6 pages Next, the compound oxide containing not only an independent zirconium dioxide but a zirconium dioxide may be used for the zirconium dioxide added to a carrier. There are ZrO25t02 and ZrO2-0aO, Zr02-MgO, Zr02-HfO2, Zr02-Y2O2, etc. in the compound oxide of a zirconium dioxide. Z r 02 have the melting point as high as 2715 degreeC, and when it is used as a catalyst carrier material, there is an effect which controls reduction of the surface area by a sinter ring and particle growth of catalyst metal. The suitable content of the zirconium dioxide in a carrier is 5 % of the weight or more. 5-% of the weight Yo Si -- when low, the addition effect of a zirconium dioxide cannot be expected. 100 microns or less of particle sizes of a zirconium dioxide are 60 microns or less especially preferably from the viewpoints of fabrication nature etc. When cell wall thickness fabricates in the shape of [ of 0.3 or less ffff ] a honeycomb, 30 micrometers or less are preferred. Next, although it is titanium oxide, the compound oxide containing not only an independent metal oxide but titanium oxide may be sufficient. 6 A page TiO2 -- Anatase and a weasel -- the crystal transformation of a tongue stone and rutile exists. In this, the high temperature of rutile M is also stable, and the temperature to which Anatase type rutile type transition takes place is near 700 degreeC. The rutile type which excelled [ present invention ] especially in heat stability although every titanium oxide of this was usable is preferred. Also as for Chi Si and these compounds, to the compound oxide of titanium oxide, Ti02-person M2O3, TiO□-Zr02, TiO25i02, TiO2MgO, and TiO2Bi2O5 *Ti02-Cd0, TiO2-8nO2, etc. are usable. The suitable content of titanium oxide in a carrier is 5 % of the weight or more. 5-% of the weight Yo Si -- when low, the effect of titanium oxide cannot be expected. The particle size of titanium oxide of 510 microns or less of Perspectives of fabrication nature is 1 micron or less especially preferably. Next, content in which titanium oxide in a carrier and a zirconium dioxide are suitable when adding simultaneously above-mentioned oxidization Jill ' Conium and titanium oxide, More than 5 weight -, preferably 1o weight Chi are the optimal, and the ratio of (9:1) of titanium oxide to a zirconium dioxide is [ the range of 7 pages (5:5) ] preferred. It mixes first with the Al Min acid lime and magnesia cement which are binding materials, only the water which is sufficient for fabrication is added succeedingly, and it mixes, and it recuperates itself and dries after fabricating in arbitrary shape, and solidifies a zirconium dioxide and titanium oxide. In this way, a catalyst carrier is obtained. This catalyst carrier has the outstanding heat resistance and toxicity-ed-proof. By addition of magnesia cement, heat-resistant performance improves greatly and the sinter ring in high temperature and reduction of specific surface area become extremely small. Yo Si and poison-ed-proof performance also still improve greatly to addition of a zirconium dioxide and titanium oxide. the catalyst carrier of the present invention -- the additive of alumina cement, magnesia cement, a zirconium dioxide, and titanium oxide -- although it is usable enough, it is the object to which the mechanical strength of a catalyst body and Sports-proof ring nature are made to increase, and it is good to add heat-resistant machine aggregate. Silica system machine aggregate, silica alumina system machine aggregate, alumina machine aggregate and also a silicate mineral, mullite, corundum, a Sirima night, and a magnesia system mineral can be used for heat-resistant machine aggregate. an operating temperature of a catalyst -- low temperature (300~700degreeC) -- the general granular system in business -- using aggregate -- high temperature (more than 700 degreeC) -- in business, it is preferred to use heat-resistant granular machine aggregate. It is the object of raising heat resistance and it is also arbitrary to add Depart alkali glass fiber, fibrous Iron wire and silica alumina textiles, asbestos, etc. As a forming auxiliary agent, if argillite, such as carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, alcohol, and bentonite, is added, fabrication will become easy more. Next, the catalyst supported on the catalyst carrier constituted by the composition mentioned above is described. A catalyst to support is mainly a platinum group metal. There are platinum, palladium, ruthenium, rhodium, and iridium in this, and a chloride or a nitrate is good as those salt. It is made to dissolve in solvents, such as water or alcohol, and these metal salt is used. although the concentration changes with the quantity and the Consensus methods which are made to adhere -- 9 Amazing beach Si -- since the dispersibility of catalyst particles worsens that it is thick solution, the optimal concentration is determined according to the purpose of use, shape, etc. When especially a platinum group metal is used, compared with the conventional platinum catalyst, the catalyst body which the amount of support of platinum excelled [ performance / initial performance and / life ] in 0.001~0.1 % of the weight can be obtained. That is, using carriers, such as alumina and a cordylite, the amount of support of platinum of especially degradation of life performance is [ the conventional platinum catalyst ] large in Ah Si and 0.1% of the weight or less of the amount of support at 0.6~0.1 % of the weight, and the above-mentioned amount of support has been general common sense. - the time of using the catalyst carrier of the Furumoto invention -- the amount of support of platinum -- a very small quantity -- also coming out -- it is high performance. Thus, if the catalyst carrier of the present invention is used, a little amounts of support, such as platinum, will come out, and a highly efficient catalyst body will be obtained. It is because some Al Min acid lime which constitutes a carrier absorbs moisture, 1203 and ncao dissolve partially, this separates a part of CaO and the solution shows alkalinity. On the other hand, Okay. of raw material of a precious metal catalyst is a chloride. For example, in the case of platinum chloride acid, it is ptcQ6 when it dissolves in page 10 of water. Since ion is the alkalinity of the above-mentioned carrier, PtCR6 (OH) is formed. This salt ptcn6 (oH) is generated near the surface of a carrier, and does not reach to the depths in fine pores. Therefore, it concentrates on the surface and does not diffuse the concentration distribution of the catalyst metal of the present invention up to the inside of a carrier. That is, a catalyst metal ion will adhere also to hydroxide and 9 ZrO2 as it is on a carrier surface as mentioned above. Since a carrier is alkaline, a compound is formed by the catalyst metallic cation and a part of carrier surface, and it adheres firmly to up to a carrier. Thus, since the support only to a surface coat is possible, the amount of support can obtain a catalyst body also with a highly efficient very small quantity. As mentioned above, although the platinum group metal was described preponderantly, they are a rare earth element, a lantern, cerium, and samarium. It is the same also about support of a up to [ the carrier of catalyst metal, such as Germany IJ Umu, ]. As salt of such catalyst metal, oxalic acid salt, a nitrate, and hydroxide are typical. 11 - If the amount of support catalysts and performance have a big relation and the amount of support usually increases, Toward" D will carry out performance so much, and when too not much large, problems, such as omission of a catalyst and uneven distribution of a catalyst, also arise. The purpose of use, shape, low-temperature activity, a life, etc. can also be made to improve by making various metal and two or more sorts of metal oxides support in addition to the amount of catalysts. Explanation of an example Example 1 The silica of Al Min acid lime, magnesia cement, and heat-resistant machine aggregate is mixed by the compounding ratio shown in the 1st table, 3o~40 weight section is added for water, methyl cellulose (4-weight section alkali-proof glass fiber and 2 weight sections) is added into 100 weight sections of the mixture, wet blending is carried out to it, and they are diameter 80 Moe and a 150-mm-thick disk by press-forming about it, It fabricated in the shape of [ which established the hole of cell wall thickness 0.5ffff and diameter of cell 1.5 mm X 1.5 MM in the thickness direction ] A \ Nicam. In A hot water bath of after-dryness 90-degreeC, it was recuperated and this was dried. Pt, Pd, and ce were used for the catalyst. pt uses platinum chloride acid water solution (2q/100cc), and is per carrier, An equivalent for 300 mg and Pd are palladium chloride solutions (1(J / 100 cc)Q using) as pt. 150 mg and Ce are cerium nitrate solutions (using 2 (J/100CC), an equivalent for e o o mq was applied as Ce, and it heat-treated by 50o"C after dryness for 1 hour, and supported Pt Pd-CeO2.) as Pd. The performance of the catalyst body obtained in this way measured and compared CO purification rate in 3001: on with space speed 50000hr and a CO entrance concentration of 300 ppm (inside of the air) conditions. Judgment of heat-resistant existence measured the performance after 100-hour heating by the performance after 1-hour heating, and 900 degreeC by 700 degreeC. The relation between heat treatment temperature and specific surface area was still seen. The heat treatment condition was respectively performed by 700degreeC, 800degreeC, 900degreeC, and 1000 degreeC about the sample of the 1st table for 3 hours. Specific surface area was measured by the BET method. A result is shown in Drawing 1. 13 Pano 1st Table The thermal catalyst de-activation of Yo Si and CO decontamination capacity is small to addition of magnesia cement so that clearly also from the above-mentioned result. Even if it measured the degree of thermal change of specific surface area, the reduction in specific surface area of the magnesia cement addition article was smallness. Example 2 Knowledge by the combination composition shown in the 2nd table, create a catalyst body like Example 1, and using 'rio2. ZrO2 and TiO2ZrO2 -- The and a toxicity test-ed [ S-proof02 ] were just done. This result is shown in the 3rd table. The test method passed the air which mixed S02 gas of 700 ppm, and CO gas of 1100pp to the catalyst body heated to 400 degreeC, measured the purification rate of CO by space speed 50000 hr every 10 hours, and measured the degree of degradation of the catalyst by S02 gas. 3rd table Yo Si -- a present invention article has the small degree of degradation clearly as compared with the catalyst body which does not contain conventional magnesia cement. (Following money white) 158 -7 2nd Table 3rd Table 17 Hay, 2 Example 3 The thermal expansion coefficient was measured about the catalyst body which changed magnesia cement into 1.3, 5, 7, and 10.12 weight charge 5i02, and was added in the combination article of Shao 1 in Example 1. A result is shown in Drawing 2. As for the amount of addition of magnesia cement, 10 % of the weight or less is preferred, and if it becomes more than 10 weight charge, a thermal expansion coefficient will increase rapidly, so that clearly from Drawing 2. EFFECT OF THE INVENTION As mentioned above, the catalyst body of the present invention is excellent in heat resistance, is stable also in life and excellent in toxicity-ed [ S-proof02 ].

[Brief Description of the Drawings]

The figure showing the heat treatment temperature of a catalyst carrier and the relation of specific surface area to an example and Drawing 2 are in the figure showing the relation of the amount of magnesia cement and thermal expansion coefficient in a carrier. [ Drawing / 1 ]