The preparation method of the catalyst for purification of exhaust gases of internal combustion engines
(57) Abstract:The invention relates to methods of producing the catalyst for purification of exhaust gases of internal combustion engines. The method includes the preliminary heat treatment of the metal carrier, coating the ceramic or metal carrier layer of aluminum hydroxide with subsequent thermal dehydration him, impregnation with aqueous solutions of salts of cerium, platinum, rhodium, drying and restoration. High temperature processing of metal carrier is carried out in the temperature range 800-1050oWith, applying a layer of aluminum hydroxide is carried out at a temperature of 20-25oWith in an aqueous solution of potassium hydroxide when dissolved therein a metal of aluminum, and the recovery of the catalyst is carried out in aqueous solution sodium borohydride. The technical result of the invention is to improve the catalyst activity, simplification and cost reduction technologies for preparation of the catalyst, the improvement of the quality of the resulting layer of gamma-alumina, the application method for the preparation of catalysts on ceramic block media with the number of channels up to 900 pieces per square inch. 3 C.p. f-crystals, 2 tab. The invention relates to methods recip what s the methods of preparation of catalysts on supports cell structure with many holes in the direction of flow of the gas stream. Source specific surface of such block of carriers is small (0.01 to 0.65 m2/g) and catalysts based on them have low catalytic activity.To increase the initial specific surface area of metallic and ceramic block media widely used application of the intermediate substrate.Known catalysts for purification of EXHAUST gas of internal combustion engine on the media block structure, the surface of which increases in a variety of ways.Often in the secondary role of the carrier-substrate is used, the aluminum oxide of the gamma phase, which has a high specific surface area (100-200 m2/g), thermal stability and chemical resistance, and the catalyst on the base of high catalytic activity.As the active component on the secondary layer of the device precipitated noble metals (platinum, palladium, rhodium), and as "oven" additives in the composition of the catalyst is injected oxides of rare earth metals (cerium, lanthanum and other).The precipitation of the rare earth and noble metals is mainly from aqueous solutions of their salts, followed by drying and recovery of the catalyst. So in the U.S. patents  (U.S. patent 4587231, B 01 J, 21/04, 1986 Sposoby the preparation of the catalyst on a carrier of honeycomb structure, on the surface of which is formed a layer of aluminum oxide by dipping the carrier in the slurry of aluminum oxide or pumping through him this suspension followed by the introduction of well-known ways of stabilizing the alumina additives and catalytic components.The main disadvantages of this method of cooking is the low adhesion coating of aluminum oxide to the surface of inert carrier, uneven coating, resulting in the life of the catalyst is reduced.To produce the desired amount of aluminum oxide on the carrier procedure of application of aluminum oxide in the slurry is repeated several times and after each operation are drying medium, which leads to additional energy consumption. In addition, with this method of preparation of the catalyst is necessary each time before drying to remove excess slurry, which leads to the inevitable loss of the suspension and increases the flow of materials. The process of removing the suspension is much harder with increasing cell densities media from 200 to 900 pieces per square inch.In the patents of the Russian Federation  (RF 2005538 C1, 5 B 01 J, 23/46, 37/03, 1992) method of preparation of the catalyst for purification of EXHAUST gas of internal combustion engine Salley heat-resistant tape with a chromium content of 15 to 23%, aluminum 1-8%. The steel corrugate, rolled into the block and subjected to high-temperature oxidation in air (900-950oC). Then in caustic soda solution (with a concentration of 0.7 to 1.5%) when dissolved therein aluminum shavings (4-5 g/l) the surface of the carrier immersed in the solution, covered with a layer of aluminum hydroxide. The process is conducted at a temperature of 40-60oC for 5-6 h, and then incubated at room temperature for 15-20 hours To produce the desired amount of aluminum hydroxide, the process is repeated 4-5 times to unload media loading the next portion of the aluminum and the subsequent loading of the carrier to continue the deposition process the substrate. Further, the carrier is washed and subjected to heat treatment at a temperature of 500oC. After thermal dehydration on the surface of the carrier is formed by a layer of gamma-alumina, which is impregnated with the aqueous solution of cerium nitrate, and after heat treatment at 450oWith an aqueous solution of hexachloroplatinic acid and rhodium trichloride, followed by drying and recovery of the catalyst with hydrogen.The described method of preparation of the catalyst is multistage and energy-intensive, because the process of applying Pro the temperature of 40-60oS-low-tech Way is because of the constant discharging from the solution and downloads in a solution of caustic soda media and aluminium to continue the process.In the patent of the Russian Federation  (RF 2121397 C1, 6 B 01 J, 21/04, 37/02, 1997) describes a method of manufacturing a catalyst, in which a layer of aluminum hydroxide on the surface of the block media form in a solution of sodium hydroxide and sodium aluminate in the presence in the solution of aluminum metal with further thermal dehydration of aluminum hydroxide and formation on the surface of the carrier layer of aluminum oxide; known methods of introducing one or more substances, stabilizing aluminum oxide, and several catalytic substances.The method described in the patent of the Russian Federation , characterized in that in order to accelerate the deposition of aluminum hydroxide and stabilize the quality of the deposited layer of aluminum hydroxide, the process is carried out using a circulating solution of sodium hydroxide and sodium aluminate along the surface of the channels of the media.The disadvantage of this method is the reduction of the specific surface of the resulting layer of aluminum oxide due to the enlargement of particles of aluminum hydroxide in the process of forced circulation of the solution, rupanya particles leads to a decrease in the secondary adhesion layer to the surface of the carrier and the service life of the catalyst.The circulation of the solution leads to increased losses of aluminum, because aluminum hydroxide formed in the solution, covers the inner surface of the equipment used for circulation of the solution (pipelines, pumps, and so on ), which leads to rapid wear of the equipment.The disadvantage of the methods according to the patent  and  is also that they cannot be used for the preparation of the catalyst on the ceramic block media. Long stay of the carrier in a solution of sodium hydroxide (120 h) to obtain a desired thickness of the coating and high temperature sodium hydroxide solution (40-60oC) lead to swelling of the ceramic material and to cracking during thermal dehydration.The purpose of the present invention is simpler and cheaper technology for preparation of the catalyst purifying EXHAUST gas of internal combustion engine and EXHAUST gas chemical plants on a block of ceramic and metal media, improving the quality of the layer of gamma-alumina (uniform deposition of a layer of uniform thickness throughout the height of the channels of the media, high adhesion to the surface of a block of media and specific surface area gamma-alumina - 160 m2/g).The closest goal of the invention is achieved by using as initial solution for the dissolution of aluminum metal and the formation of aluminum hydroxide - solution of potassium hydroxide with a concentration of 2,0-2,5%. The high chemical activity of KOH with respect to the aluminum allows to carry out the process at room temperature, to enter into the solution of the entire portion of the aluminum required to obtain the desired number of coatings of aluminum oxide, and to reduce the time of applying a layer of aluminum hydroxide up to 20-30 hoursThe essence of the proposed method of preparation of the catalyst is as follows.As the inert carrier take a block of ceramic or metal block media with the number of channels up to 900 pieces/inch2(150 pcs./cm2).Block metal carrier is made of a steel tape heat resistant alloy grades HU, HU, HU with a chromium content of 15-23%, aluminum 3-5%. The steel corrugate, rolled into the block and degrease by known methods, for example, in an alkaline solution at a temperature of 40-60oWith the use of ultrasound. Then a metal unit is washed and dried at a temperature of 100-120oC. Next, a metal block is subjected to oxidation in air in the temperature range 800-1050oC.Block ceramic media (cordierite, hematite, rutile, etc.,) not to be robotany metal block (or a block of ceramic media) are coated with aluminum hydroxide in 2.0-2.5% solution of caustic potash by direct dissolution therein of aluminum shavings mainly grade a-95. For this purpose a solution of KOH put the estimated amount of aluminum to obtain a coating of the required mass, and then in a container with a solution on the boot grill place the unit carrier.The process is carried out without additional heating at room temperature (20-25o(C) for 20-30 hours Then the unit with a coating of aluminum hydroxide is washed, dried and subjected to thermal dehydration in the temperature range 100-550oC.A coating of aluminum oxide impregnated with aqueous solutions of salts of CE(NO3)3N2PtCl6and RhCl3with subsequent drying and recovery of platinum and rhodium, for example, hydrogen. To facilitate equipment design process of recovery of the catalyst with hydrogen may be replaced by recovery of the catalyst in aqueous solution sodium borohydride followed by washing and drying at a temperature of 100-120oC.The inventive method allows to obtain a catalyst having high catalytic activity in the oxidation of CO, CNH and reduction of NOx.Applied uniformly, strongly associated with the inert carrier substrate of gamma-aluminum oxide has a high specific surface area (120-160 m<The proposed method for the preparation of the catalyst makes it possible to simplify the manufacturing technology of the carrier with a coating of aluminum oxide, to reduce the time of applying a layer 3-4 times, which will increase the efficiency of the technological line for preparation of the catalyst in 2-3 times without replacement equipment and increase its volume.Furthermore, the method of preparation of the catalyst allows to reduce energy consumption at the stage of applying a secondary layer and multiple loading media and aluminum in solution coating, i.e., allows to make the process of applying aluminum hydroxide in one stage.The decrease in solution temperature and residence time block media in KOH solution allows the use of this method for the preparation of the catalyst on the ceramic block media of any composition (cordierite, hematite, rutile, and others) with the number of channels up to 900 pieces/inch2.Example 1 (comparative). Of the corrugated foil stamps HU 0.05 mm thick and 30 mm wide by imposing corrugated and flat strips fold unit with a diameter of 25 mm with the number of channels 400 pieces/inch2. Unit oxidizes in air at a temperature of 900-950oC for 24 h, quenching C.The unit weight of 9.9 g placed in a beaker with 100 ml of a 0.7% aqueous sodium hydroxide solution, heated contents in a water bath to a temperature of 60-80oWith add 0.4 g of aluminum shavings (sod. Al - 99,9%) and incubated in a water bath for 5 h and then at room temperature for 19 hours To increase the number of coatings of aluminum hydroxide, after holding block at room temperature for 19 h, the cycle is repeated three more times. Thus the total time of the process of applying aluminum hydroxide and 96 h, and the number of metallic aluminum in the amount of 1.6, Then the block is removed, thoroughly washed, dried 2 hours at a temperature of 100-120oWith and calcined 2 hours at a temperature of 250oC and 3 hours at a temperature of 500oC. Block with a coating of aluminum oxide weighs 12.3 g, the content of Al2ABOUT3- 2.4 g, which is ~20 wt.%.In a beaker with 25 ml of 2% aqueous solution of CE(NO3)3place the block, leave for 15-20 min the solution is completely absorbed into the channels of the block. Then the block is dried at a temperature of 100-120oWith 2 h and calcined at a temperature of 450oS - 3 hours After the annealing the block weighs 12,54 g and contains 10 wt.% SEO2based on the weight of the coating of Al2ABOUT3that is 1.9 wt.% from the mass of the block.100 THEO (sod. Rh-36,0 wt.%). The solution was placed a block and incubated in the solution at room temperature for 20-24 hours, then taken out, dried at a temperature of 100-120oC for 2 hRestore the active components are in hydrogen at a temperature of 400oC for 5 hThe catalyst weighs 12,55 g and contains, wt%:
Pt - 0,1
Rh - 0.02
Steel HY - Rest
Example 2. Of the corrugated foil stamps HU 0.05 mm thick and 30 mm wide by imposing corrugated and flat strips fold unit with a diameter of 25 mm with the number of channels 400 pieces/inch2. Unit degreased, washed and dried at a temperature of 100-120oC. Unit oxidizes in air in the temperature range 800-1050oC for 24 hIn a beaker with 100 ml of 2% aqueous solution of caustic potash added 1.45 g of aluminum shavings (sod. Al - 99,9%), immediately put the unit weight of 9.9 g and incubated at room temperature for 15 hours Then the unit is removed, thoroughly washed, dried at a temperature of 100-120oWith 2 h and calcined at a temperature of 250oWith 2 h and at a temperature of 550oC - 3 hour Block with a coating of aluminum oxide weighs 12.4 g, contains Al3ABOUT3- 2.5 g that sostman - the solution is completely absorbed into the channels of the block. Then the block is dried at a temperature of 100-120oWith 2 h and calcined at a temperature of 500oS - 3 hours After the annealing the block weighs 12,63 g and contains 10 wt.% SEO2based on the coating weight of Al2ABOUT3that is 1.9 wt.% from the mass of the block.In 25 ml of distilled water dissolve 33,7 mg H2Ptl66N2On (sod. Pt - 37.5 wt. %) and 7.0 mg Rl34H2On (sod. Rh - 36,0 wt.%), place the block, the solution is completely absorbed into the channels of the block. The block is removed, dried at a temperature of 100-120oC for 2 hRestore the active components are in hydrogen at a temperature of 400oC for 5 hThe catalyst weighs 12,64 g and contains, wt%:
Pt - 0,1
Rh - 0.02
Steel HY - Rest
Example 3. Analogously to example 2, but with the aim of increasing the number of aluminum oxide, the amount of aluminum shavings increase to 2.4 g, and the concentration of KOH increase to 2.5%.The block is kept in the solution for 24 h at room temperature. Next, as in example 2.After heat treatment unit with a coating of aluminum oxide weighs 14.1 g, weight of coating Ale increase in 3 times. Further according to the example 2.Block after impregnation with a solution of cerium nitrate, drying and calcination weighs 14.5 grams and contains ~ 10 wt.% SEO2with respect to the coating weight of Al2ABOUT3(by weight of the total block a content SEO22.9 wt.%). A number of salts of platinum and rhodium in the example is:
H2PtCl66N2On (sod. Pt - 37.5 wt.%) - 38,45 mg and RhCl34H2On (sod. Rh - 36,0 wt.%) to 8.0 mg.The dissolution of salts impregnation unit and recovery of the catalyst is carried out according to example 2.The catalyst weighs 14,53 g and contains, wt%:
Pt - 0,1
Rh - 0.02
Steel HY - Rest
Example 4. Analogously to example 2, but in 100 ml of 2% aqueous solution of KOH take 1.1 g of aluminum shavings. The block weighs 11,7 g, a coating of Al2ABOUT3weighs 1.8 g, which is ~ 15 wt.% from the total mass of the block. For impregnating solution take a 1.5% solution of CE(NO3)3then example 2.Block after impregnation with a solution of cerium nitrate, drying and calcination weighs 11.9 g and contains ~ 10 wt.% SEO2with respect to the coating weight of Al2ABOUT3(by weight of the total block a content SEO21.5 wt.%). Kolichestvo RhCl34H2On (sod. Rh - 36,0 wt. %) and 6.6 mg Dissolution of salts, impregnation unit and recovery of the catalyst is carried out according to example 2. The catalyst weighs 11,91 g and contains, wt%:
Pt - 0,1
Rh - 0.02
Steel HY - Rest
Example 5. Analogously to example 2, but in 50 ml of 2% aqueous solution of KOH take 0.7 g of aluminum shavings. The block weighs 11.1 g, a coating of Al2ABOUT3weighs 1.2 grams, which is 10.8 wt.% from the total mass of the block. For impregnating solution take 1% solution of CE(NO3)3then example 2.Block after impregnation with a solution of cerium nitrate, drying and calcination weighs 11,21 g and contains ~ 10 wt.% SEO2with respect to the coating weight of Al2ABOUT3(by weight of the total block a content SEO2of-1.0 wt.%). A number of salts of platinum and rhodium in the example is:
H2PtCl66N2On (sod. Pt - 37.5 wt.%) - 29,9 mg and RhCl34H2O (sod. Rh - 36,0 wt. %) and 6.2 mg of the Dissolution of salts impregnation unit and recovery of the catalyst is carried out as in example 2.The catalyst weighs 11,22 g and contains, wt%:
Pt - 0,1
Rh - 0.02
Steel HO ABOUT omicheskogo media (production IPC RAS), for example, rutile diameter 25 mm, height 30 mm and a weight of 12.6 g with the number of cells 140 pieces/cm2. Block with a coating of aluminum oxide weighs 15.1 grams, contains Al2ABOUT3in the amount of 2.5 g that is ~ 16.2 wt.%.After treatment with 2% solution of CE(NO3)3and annealing the block weighs 15,35 g and contains 10 wt.% SEO2based on the weight of the coating of Al2ABOUT3that is 1.6 wt.% from the mass of the block.A number of salts of platinum and rhodium in the example is:
H2PtCl66N2On (sod. Pt - 37.5 wt.%) - 41.7 mg and Rl34H20 (sod. Rh - 36,0 wt. %) - 8,7 mg Dissolution of salts, impregnation unit and recovery of the catalyst is carried out according to example 2.The catalyst weighs shed 15.37 g and contains, wt%:
Pt - 0,1
Rh - 0.02
Rutile - Rest
Example 7. Analogously to example 2, but after impregnation unit with a solution of salts of noble metals and drying at a temperature of 100-120oWith the recovery of the catalyst is carried out in 3% solution of sodium borohydride (NaBH4) at pH 12 and at room temperature. The block is placed in a 100 ml solution and incubated for 20-30 min, then washed and dried at a temperature of 100-120oWith those
Pt - 0,1
Rh - 0.02
Steel HY - Rest
The catalytic activity of samples of the catalysts was tested in a laboratory flow-through installation in a three-part process of cleaning gas composition, vol.%:
CO - 0,4
NO - 0,1
Nitrogen - Rest
when flow rate - 30000 h-1.Test data are given in table. 1.The catalytic activity increases in the number 5 < 1 < 7 < 4 < 2 < 6 < 3. The temperature is ninety percent (T90) conversion of CO3H6and NO for samples 2, 4 and 6 are almost identical, which allows to conclude that the content of aluminum oxide in the amount of 15-20 wt.% is optimal for creating an effective catalyst for purification of exhaust gases of internal combustion engines.The temperature is ninety percent (T90) conversion of CO3H6and NO for sample 3 is slightly lower, but with increasing thickness of the secondary layer, the resistance of the catalyst layer increases, which is undesirable for converters of EXHAUST gas of the engine.Measurement of the specific surface of the samples of catalysts and carriers was performed by the method of low-temperature nitrogen sorption (BET method) in static conditions at constant D. the way, 20-30% more compared to the prototype. The results are given in table. 2.Were conducted as the study of the microstructure of the coatings on the optical microscope "Neophot-21" Zeiss (Germany) with a magnification of 500 times. Analysis method - crystal optics, the reflected light on the thin sections made from fragments of block media of examples 1 (prototype) and 2.The results showed that the coating according to example 2 is a single-layer coating, uniform, dense, optically amorphous; the thickness of 70-90 microns.The coating of example 1 (prototype) is a two-layer coating in the form of spherulites, grouped into conglomerates. The first layer adjacent to the base, which is formed at the initial stage of the coating process, dense, uneven layer thickness, the size of spherulites 10-15 µm, sometimes up to 50 μm. The second layer, which is formed by increasing the exposure time, more voluminous and loose. The dimensions of the growing structural formations of spherulites reach 50-100 μm. The total thickness of the aluminum oxide layer obtained in example 1 (prototype), is 50-130 μm.Thus, longer coating in rasterline, that adversely affects the service life of the catalyst. Consolidation of structural formations leads to a decrease in the end, the specific surface of the sample of the catalyst of example 1 (prototype) and the reduction of its catalytical activity.In the Experimental production of IPC RAS were made full-size samples of catalysts on ceramic block carrier by the claimed method and road tests have been conducted on the car GAZ-24 to ground US. The catalyst showed high efficiency of purification of exhaust gases, the required resource work and was recommended for practical use.The efficiency of the catalyst on a metal block carrier evidenced by minutes of full-scale tests full-sized catalytic converters, custom pilot production of the Institute Russian Academy of Sciences, held at the automobile plants of OJSC "Moscow", OJSC "ZIL" and OJSC "GAZ".Sources of information
1. U.S. patent 4868148, B 01 J 23/10, 19892. U.S. patent 4868149, B 01 J 23/10, 19893. European patent 0337809, B 01 J 23/56, 19894. RF 2005538 C1, 5 B 01 J 23/46, 37/03, 19925. RF 2121397 C1, 6 B 01 J 21/04, 37/02, 1997 1. The method of preparation of the catalyst the Loya aluminum hydroxide with subsequent thermal dehydration him, impregnation with aqueous solutions of salts of cerium, platinum, rhodium, drying and restoration, characterized in that applying a layer of aluminum hydroxide is carried out at room temperature in an aqueous solution of potassium hydroxide with the direct dissolution therein of metallic aluminum.2. The method according to p. 1, characterized in that the deposition of aluminum hydroxide is carried out at a temperature not exceeding 25oWith the solution of potassium hydroxide with a concentration of not higher than 2.5% by direct dissolution therein of metallic aluminum in the form of chips.3. The method according to p. 2, characterized in that as the inert carrier used ceramic block carrier of cordierite, rutile or hematite with the number of channels 600-900 pieces /inch2.4. The method according to p. 1, characterized in that the recovery of the catalyst is carried out in aqueous solution sodium borohydride followed by rinsing and drying of the finished catalyst.
FIELD: inorganic synthesis catalysts.
SUBSTANCE: invention provides ammonia synthesis catalyst containing ruthenium as active ingredient supported by boron nitride and/or silicon nitride. Catalyst can be promoted by one ore more metals selected from alkali, alkali-earth metal, or rare-earth metals. Ammonia synthesis process in presence of claimed catalyst is also described.
EFFECT: increased temperature resistance of catalyst under industrial ammonia synthesis conditions.
4 cl, 6 ex
FIELD: alternate fuel manufacture catalysts.
SUBSTANCE: invention relates to generation of synthesis gas employed in large-scale chemical processes such as synthesis of ammonia, methanol, higher alcohols and aldehydes, in Fischer-Tropsch process, and the like, as reducing gas in ferrous and nonferrous metallurgy, metalworking, and on gas emission detoxification plants. Synthesis gas is obtained via catalytic conversion of mixture containing hydrocarbon or hydrocarbon mixture and oxygen-containing component. Catalyst is a complex composite containing mixed oxide, simple oxide, transition and/or precious element. Catalyst comprises metal-based carrier representing either layered ceramics-metal material containing nonporous or low-porosity oxide coating, ratio of thickness of metallic base to that of above-mentioned oxide coating ranging from 10:1 to 1:5, or ceramics-metal material containing nonporous or low-porosity oxide coating and high-porosity oxide layer, ratio of thickness of metallic base to that of nonporous or low-porosity oxide coating ranging from 10:1 to 1:5 and ratio of metallic base thickness to that of high-porosity oxide layer from 1:10 to 1:5. Catalyst is prepared by applying active components onto carrier followed by drying and calcination.
EFFECT: increased heat resistance and efficiency of catalyst at short contact thereof with reaction mixture.
13 cl, 2 tbl, 17 ex
FIELD: methods of production a synthesis gas.
SUBSTANCE: the invention is pertaining to the process of production of hydrogen and carbon oxide, which mixture is used to be called a synthesis gas, by a selective catalytic oxidation of the hydrocarbonaceous (organic) raw material in presence of the oxygen-containing gases. The method of production of the synthesis gas includes a contacting with a catalyst at a gas hourly volumetric speed equal to 10000-10000000 h-1, a mixture containing organic raw material and oxygen or an oxygen-containing gas in amounts ensuring the ratio of oxygen and carbon of no less than 0.3. At that the process is conducted at a linear speed of the gas mixture of no less than 2.2 · 10-11 · (T1 + 273)4 / (500-T2) nanometer / s, where: T1 - a maximum temperature of the catalyst, T2 - a temperature of the gas mixture fed to the contacting. The linear speed of the gas mixture is, preferably, in the interval of 0.2-7 m\s. The temperature of the gas mixture fed to the contacting is within the interval of 100-450°C. The maximum temperature of the catalyst is within the interval of 650-1500°C. The technical effect is a safe realization of the process.
EFFECT: the invention ensures a safe realization of the process.
10 cl, 5 ex
FIELD: petrochemical process catalysts.
SUBSTANCE: catalyst contains, wt %: group VIII metal 0.01-2.0, group IVA metal 0.01-5.0, europium 0.01-10.0, cerium 0.10-10.0, halogen 0.10-10.0m and refractory inorganic oxide 63.00-99.86.
EFFECT: enabled preparation of catalyst with relatively high activity and selectivity, low carbon sedimentation velocity, and prolonged lifetime in naphtha reforming processes.
11 cl, 6 dwg, 4 tbl
FIELD: production of catalytic neutralizers.
SUBSTANCE: high-efficiency catalytic neutralizer has internal and external layers on inert carrier which contain noble metals of platinum group deposited on materials of base and oxygen-accumulating components. Inner layer of proposed catalytic neutralizer contains platinum deposited on first base and first oxygen-accumulating component and its external layer contains platinum and rhodium deposited on second base only; this second layer contains additionally second oxygen-accumulating component. Production of catalytic neutralizer includes application of coat on carrier made from composition containing powder-like materials including first material of base and first oxygen-accumulating component followed by drying, calcining, immersing the carrier with coat in solution of platinum precursor; coat is calcined and external layer is applied over previous layer. Specification describes two more versions of production of catalytic neutralizer.
EFFECT: enhanced ability of catalytic neutralizer for reduction of catalytic activity after aging due to discontinuation of delivery of fuel.
24 cl, 1 dwg, 11 tbl, 5 ex, 3 ex
FIELD: production of hydrogen and carbon oxide referred to as synthesis gas by selective catalytic oxidation of hydrocarbon raw material in presence of oxygen-containing gases.
SUBSTANCE: proposed method includes bringing the starting material in contact with catalyst at hourly volume rate of gas within 10,000-10000000 h-1; mixture contains organic material and oxygen or oxygen-containing gas in the amount ensuring ratio of oxygen to carbon no less than 0.3; electric current is passed through at least part of catalyst. Used as catalysts are complex composites including metallic carriers.
EFFECT: possibility of quick and safe ignition of catalyst; increased degree of conversion and selectivity under conditions of change of load in wide range.
24 cl, 7 ex
FIELD: inorganic synthesis catalysts.
SUBSTANCE: ammonia synthesis catalyst includes, as catalytically active metal, ruthenium deposited on magnesium oxide having specific surface area at least 40 m2/g, while concentration of ruthenium ranges between 3 and 20 wt % and content of promoter between 0.2 and 0.5 mole per 1 mole ruthenium, said promoter being selected from alkali metals, alkali-earth metals, lanthanides, and mixtures thereof. Regeneration of catalytic components from catalyst comprises following steps: (i) washing-out of promoters from catalyst thereby forming promoter-depleted catalyst and obtaining solution enriched with dissolved promoter hydroxides; (ii) dissolution of magnesium oxide from promoter-depleted catalyst in acidic solvent wherein ruthenium is insoluble and thereby obtaining residual ruthenium metal in solution enriched with dissolved magnesium compound; and (iii) regeneration of residual ruthenium metal from solution enriched with dissolved magnesium compound via liquid-solids separation to form indicated solution enriched with dissolved magnesium compound and ruthenium metal.
EFFECT: increased catalyst activity.
6 cl, 6 ex
FIELD: catalyst preparation methods.
SUBSTANCE: invention relates to a method for preparing catalyst and to catalyst no honeycomb-structure block ceramic and metallic carrier. Preparation procedure includes preliminarily calcining inert honeycomb block carrier and simultaneously applying onto its surface intermediate coating composed of modified alumina and active phase of one or several platinum group metals from water-alcohol suspension containing, wt %: boehmite 15-30, aluminum nitrate 1-2, cerium nitrate 4-8, 25% ammonium hydroxide solution 10-20, one or several precipitate group metal salts (calculated as metals) 0.020-0.052, water-to-alcohol weight ratio being 1:5 to 1:10; drying; and reduction. Thus prepared catalyst has following characteristics: specific coating area 100-200 m2/g, Al2O3 content 5-13%, CeO2 content 0.5-1,3%, active phase (on conversion to platinum group metals) 0.12-0.26%.
EFFECT: simplified technology due to reduced number of stages, accelerated operation, and high-efficiency catalyst.
5 cl, 1 tbl, 10 ex
FIELD: industrial organic synthesis catalysts.
SUBSTANCE: catalyst contains following active components: Pd (0.001-1%), Bi (0.001-5%), at least of Ag, Cu, Zn, K, Na, Mg, Ca, Be, Sn, Pb, Cd, Sr, Ba, Ra, Mn, Zr, Mo, and Ge (0.001-10%), and at least one of rare-earth metals deposited on porous inorganic carrier (the balance.). Catalyst is capable of selectively and rapidly hydrogenating strongly unsaturated hydrocarbons such as alkynes. Catalyst is suitable for industrial cracking process and is characterized by favorable long regeneration period, long service time, and low cost.
EFFECT: improved performance characteristics of catalyst at low cost.
23 cl, 5 tbl, 22 ex
FIELD: gas treatment catalysts.
SUBSTANCE: invention provides catalyst consisted of inert carrier and catalytic coating containing platinum, rhodium, and oxide substrate, wherein catalytic coating includes: (i) at least one first substrate material selected from group consisted of first active aluminum oxide enriched with cerium oxide; mixed oxide, which is cerium oxide/zirconium dioxide; and zirconium dioxide component; provided that catalytic component in at least one first substrate material is first portion of the total quantity of catalyst platinum, wherein concentration of the first portion of the total quantity of catalyst platinum lies within a range of 0.01 to 5.0% of the total mass of catalyst-containing materials; and (ii) a second substrate material containing second portion of total quantity of platinum and rhodium as catalytic component, said second substrate material being second active aluminum oxide, wherein concentration of platinum plus rhodium on the second substrate material lies within a range of 0.5 to 20% of the total mass of the second substrate material. Method for preparing above catalyst is also provided.
EFFECT: increased catalytic activity and reduced catalyst preparation expenses.
17 cl, 3 dwg, 5 tbl, 3 ex
FIELD: heterogeneous catalysts.
SUBSTANCE: catalyst contains porous carrier, buffer layer, interphase layer, and catalytically active layer on the surface wherein carrier has average pore size from 1 to 1000 μm and is selected from foam, felt, and combination thereof. Buffer layer is located between carrier and interphase layer and the latter between catalytically active layer and buffer layer. Catalyst preparation process comprises precipitation of buffer layer from vapor phase onto porous carrier and precipitation of interphase layer onto buffer layer. Catalytic processes involving the catalyst and relevant apparatus are also described.
EFFECT: improved heat expansion coefficients, resistance to temperature variation, and reduced side reactions such as coking.
55 cl, 4 dwg