Method of obtaining catalyst of epsilon-caprolactam polymerisation
SUBSTANCE: described is a method of obtaining a catalyst of an anionic ε-capralactam polymerisation by its direct interaction with an alkali metal compound in the presence of an aprotic solvent, removed after reaction completion, with a reaction being carried out at a temperature not lower than 60°C, with hydroxides or their combinations being applied as alkali metal compounds, and as active diluents - aliphatic hydrocarbons with the number of carbon atoms in the interval 5-9 or their mixtures, which form with a reaction product - water heterogenic azeotropes, removed in the course of conversion.
EFFECT: simplification and intensification of the catalyst obtaining process, increase of the catalyst activity.
2 cl, 1 tbl, 3 ex
The invention relates to the production of polyamides, in particular nylon-6, which is one of the notable places in the world production of plastics. It is known that since the creation and almost up to the present time the main production process of this plastic is the so-called "hydrolytic" method, under which the initial monomer - semicolony amide cycle (ε-aminocaproyl) open at a high temperature of 240-270°C in the presence of 1-4% water and various acids (adipic, ε-aminocaproic). Get enough linear polymer with a molecular weight in the range 15-50 thousand and a residual monomer content of up to 10%, which necessitates a subsequent washing with water. Nylon-6 with the specified background is spent on obtaining fibers with unmatched value tensile strength [1. V.V. Korshak, T.M. Frunze. Synthetic straight-chain polyamides. Ed. An SSSR, Moscow. 1962].
"Catalytic" method presents anionic polymerization of ε-caprolactam under the action of metal-containing lactamases (lactamica sodium) in the presence of various accelerators of polymerization (N-acetylcaprolactam) and is characterized by significantly lower polymerization temperatures (170-180°C)and lower residual monomer content that allows you to use the substance of this method for the production of injection (construction) of products with high resistance to shock loads [2. T.M. Frunze, V. Kurashov, V. A. Kotelnikov. T.V. Volkova. USP, .XLV111, VIP, 1973, 1856-1883].
Recently, in connection with the expansion of applications of nylon-6 and the creation of nanocomposites based on it with mineral fillers, there is an urgent need to develop new and improved methods of obtaining this polymer, which would be able to solve several problems simultaneously:
- curing in situ filling of the polymer (RIM technology), which has many advantages over conventional mixing,
- intensification of the process of synthesis of the polymer and composites on its basis, which would allow to combine in a single process synthesis polymer and molding products (extruder technology)
- search for new catalysts and improving the technology of their synthesis, especially in reducing the fire and explosion and increase their purity.
To a significant extent, the task can be solved by the creation of new catalytic systems and to improve the technology of their synthesis.
Currently, there are a significant number of anionic polymerization catalysts and methods for their preparation. A dominant position is lactamin sodium, obtained mainly by the direct contact of the metallic sodium in the molten lactam, ongoing agnostic is Ino, directly in the polymerizing system [3. H. Yumoto, N. Ogata. Bull. Chem. Soc. Japan, 31, 973, (1958)] or previously, obtaining first concentrate catalyst patents 4. EP 1191050, 5. FR 2291231, 6. EN 2036933, 7. EN 2074866].
The method is characterized by a high rate of synthesis, high heat dissipation and, consequently, significant overheating of the alkali metal, leading to acceleration of the reaction and poor accountability. In addition to the main product, there are side connections - products recovery of lactam (cyclic imine, amines, acid salts), which contaminate the catalyst and do not reproducible polymerization process. Significant technological difficulties are created by the hydrogen produced in the synthesis process lactamase sodium, driving to translate the process into the category of flammable and explosive.
In this regard, considerable attention is paid to the development of methods for producing catalysts for anionic polymerization, which would eliminate the disadvantages inherent in the technology that uses alkali metals.
A partial solution to the problem can make use of finely crushed dispersions of alkali metals in an inert solvent patents 8. GB 1458653, 9. GB 1265050].
More effective is the use as starting product for the synthesis lactamases instead of alkaline IU allow their hydrides, which react with the lactam much more calm and allow the well to monitor the progress of the reaction. However, this saves vosstanovitelnye properties of hydrogen and the difficulties associated with its disposal. The advantage of this method is the possibility to obtain 100%conversion of the lactam and catalyst not containing excess patents 8-9, 10. EN 1779245, 11. EN 1754203].
Mitigation the reaction conditions obtaining metal-containing lactamases using as initial products of alkali metals or their hydrides is also achieved by applying the synthesis of aprotic solvents (ethers, tetrahydrofuran). These solvents reduce overheating of the alkali metal and contributes to the overall lowering of the reaction temperature [8-11]. In this sense deserves the attention of the method, using as a reaction medium liquid ammonia [12. patent RU 1774940]. The process of obtaining lactamase sodium can be maintained at a temperature of -40°C to yield the pure target product 99,3%.
However, a more radical solution to the problem seems to be the replacement of alkali metals, ORGANOMETALLIC compounds or hydrides, oxides, hydroxide or alcoholate emitting synthesis lactamases water instead of hydrogen, which can be removed by known methods, shifting thus the equilibrium lactamin ↔ hydrolysis of the t in the direction of the desired metal-containing catalyst.
For example, it is known the use of lower alcoholate individual alcohols or their combinations with the highest in the synthesis lactamase sodium [13. patent EP 0238143]. It is argued that the addition of higher alcohol stabilizes the formed catalyst. However, the drawback of this method is the difficulty of removing residual alcohol from the catalyst, due to the presence of it in coordination (solvation) sphere of sodium, which violates the further course catalyzed polymerization sensitive to proton donors.
Deserve attention and a hydride system used to obtain lactamase sodium, for example, mixed hydrides of sodium and aluminum [14. patent PL 129834]. As metalliser caprolactam agent taken hydrides composition NaH·AlH3, NaH·(AlH3)2, (NaH)3·AlH3. The metallation reaction was carried out in an environment of diethyl ether at room temperature for 2-5 hours. The reaction mixture is filtered off from the remnants of the hydrides and the clarified product is evaporated in vacuum. Get lactamin sodium with the release of 95-98% and a purity of 99.5%.
Combining applies themselves catalytic systems. The proposed binary system, a combination of lactamica sodium Lewis sites and various acids [15. patent EP 0613917]. Although the process of synthesis is not easier, but the resulting produce what the market will allow you to get Homo - and copolymers of amides, characterized by increased resistance to shock loads.
As can be seen from the presented list, the use of different solvents in the synthesis caprolactamate sodium and other metal intermediates of lactam systems, the metal-solvent, the metal hydride-solvent, the anion of the metal-solvent and completely absent for alkali-solvent. In addition, the combined binary metal systems are presented only for mixed catalysts based on metals of the first and second groups of the Periodic system and completely absent in the case of metals of the first group.
As the closest technical solution with respect to the claimed selected European patent EP 0238143, in which the receiving lactamases alkali metal is carried out in two stages. First, in the first stage by dissolving an alkali metal in a low molecular weight alcohol and the subsequent distillation of the alcohol receive individual alcoholate of alkali metals. The reaction is carried out in an excess of alcohol, at room temperature with the application of vacuum at the end of the process. In the second stage, the resulting alcoholate is reacted with ε-caprolactam for 2-16 hours in an environment of aliphatic or aromatic solvents. Released in the reaction alcohol is also removed by simple distillation. For the activation process in which the system adds small amounts of higher alcohols (C 4-C8). The disadvantage of this method is that it is dvukhstadiinoi and the difficulty of removal of a small alcohol residue, disrupting subsequent polymerization.
The technical problem of the invention consists in the intensification of the process of synthesis catalysts, obtaining them in a more active state by combining with each other and transfer it to the one (hydrogen-free) technology.
This problem is solved by using as initial products of metallcia of lactam oxides, hydroxides of alkali metals or mixtures thereof and holding it in the aliphatic C5-C9aliphatic diluents, which not only form a heterogeneous azeotrope with eye-catching as a result of reaction with water, but also trigger the fusion reaction catalyst. Azeotropic drying of the product is more effective than simple distillation and does not require vacuum.
The authors found that aliphatic hydrocarbons are very kind towards caprolactam: at temperatures below its melting temperature (69,3°C) caprolactam practically does not dissolve. If you exceed this the melting temperature just a few degrees, there is a perfect combination of molten lactam with hydrocarbon (visually quite clear solution), and almost regardless what about on the composition of the initial mixture. Reverse cooling of the mixture causes a sharp drop of the lactam and the stratification system in two layers, with direct and reverse temperature are almost the same. This peculiarity leads us to qualify these hydrocarbons as solvents and diluents. In such combined visually homogeneous, rasprave-solution, active environment and is the reaction for the synthesis of catalysts in accordance with the claimed formula. The choice of the above-mentioned environment for the reaction provided the possibility of removal of the reaction product (water) in the form of a heterogeneous azeotrope. dewatering capacity of above simple distillation. It should be noted that depending on fossil fuel is abruptly changed the "capacity" of the resulting azeotrope water (1% for pentane up to 40% for nonane). This fact must be considered when choosing the number of additions needed for complete removal of the formed water. The undeniable advantage of the chosen azeotrope is its heterogeneous nature, namely, that when cooling is carried out vapors and their subsequent condensation is complete separation of water and hydrocarbons, which can be reused almost without drying because water solubility in aliphatic hydrocarbons are negligible (e.g. the, in hexane or heptane at a level of 0.01%).
The combination of alkali metals to modify the properties of the catalytic system (activity, stereotypicality, the propensity to adverse reactions, and so on) - reception well known in the anionic polymerization of the vinyl or diene monomers [16. M. Schwartz. Anionic polymerization. Ed. MIR, Moscow, 1971]. For example, combining lithium with sodium or potassium fully translates the microstructure of the obtained polydiene with 1,4-type joining of monomer units in the 1,2 - or 3,4-translates the block structure of the block-copolymer of styrene with butadiene statistical, gives the ability to significantly activate the reaction of chain transfer and to receive liquid oligodiens etc. the Combination of alkali metals is well known and at the stage of receipt of the catalysts. For example, the synthesis of organolithium compounds is catalyzed by the addition of sodium. The specified combination in the synthesis of catalysts for the anionic polymerization of lactam, as well as in the polymerization, was not applied in this situation so far concerns only get themselves catalysts.
The technical essence of the invention consists in the following. The reaction of obtaining lactamases alkali metals provide direct interaction of ε-caprolactam with a solid alkali, taken individually or in mixture with each other is om. The composition of the mixture and combine reagents can be selected arbitrarily. It is noted that the mixture of alkalis, such as sodium and potassium, is reacted with a lactam in the same conditions more strongly than individual. Not excluded and ternary mixtures of lithium, sodium and potassium alkalis. It is also noted that mutual catalytic effect of metals on each other is observed in the phase response, when at least a small part of any lye will dissolve. In this regard, mutual catalysis can be carried out by adding, for example, potassium ready lactamase to the newly synthesized sodium. The molar ratio of lactam and alkali is not critical and can be chosen arbitrarily, from a few mole percent of alkali (excess lactam) to almost 100% lactam (excess alkali). High activity in the reaction.
As a reaction medium selected mixture of lactam with aliphatic hydrocarbon with the carbon atoms is from 5 to 9 (preferably 6-8). The originality of the selected environment is that it begins to operate at a temperature above the melting point of the lactam at least a few degrees, when the melt is completely combined with the additive or give two resumemusic layer, in which the lactam is distributed homogeneous. At temperatures below 60°C is observed stratification Rea the operating environment. The upper temperature limit is determined by the TKipazeotrope and depends on the chosen solvent. When using solvent mixtures upper temperature limit is determined by the solvent with the highest TKipazeotrope (100°C).
Advantage of selected hydrocarbon additives is the formation of a heterogeneous azeotrope with the reaction product of water and active its removal from the reaction zone, which effectively shift the equilibrium in the direction of the resulting catalyst (see above). The following table shows the composition and boiling point azeotropic mixtures of water with selected hydrocarbons:
|the type and composition of the azeotrope||TKip. azeotrope °C||TKip.hydrocarbon °C|
|(according to 17. A. Gordon, R. Ford. Satellite chemist. Ed. WORLD. Moscow 1976, p.33-39).|
The table shows that the most optimal supplements, balanced by boiling and composition are heptane and cyclohexane. Not excluded, and a mixture of hydrocarbons, which are widely used in organic synthesis or in the production of polymers (e.g., nefras in the synthesis of polyethylene or refined gasoline).
The proposed method of producing catalysts for the anionic polymerization of lactam has the following technical advantages over the prototype:
- single-stage process, in the prototype process is divided into 2 stages, each of which requires removal of the intermediate product (hydrogen, ethanol),
- azeotropic dehydration of the product easier and more effective than simple distillation using vacuum,
- time process cycle is significantly reduced, up to half an hour compared to 2-15 hours in the prototype,
mixed alkali more active in the synthesis of catalyst than the individual.
The invention can be illustrated by the following examples.
In a glass flask with a capacity of 0.5 liters, equipped with a stirrer, a heater, and refrigerator to collect azeotrope download 4.0 g of solid cheshireman alkali sodium (free from carbonate), preferably with a particle size not exceeding in diameter 3-4 mm, cheshuirovannyj lactam in the amount of 113 g and fill in heptane in the amount of 25 ml, the Mixture is heated to melt the lactam and the formation of homogeneous mixture with heptane (79-80°C). Allowed in the course of the mixer and bring the temperature to start the reaction, which is firmly fixed on intensive boiling azeotropic mixture of the above solid alkali (about 99°C). The reaction is carried out until complete dissolution of alkali and boiling hydrocarbon. It usually takes 30-60 minutes (depending on the size of the particles of alkali). Pair azeotrope condense, separate detached water and hydrocarbon use again. Get a homogeneous, colourless melt crystallized with a marked hypothermia (10-30°C below Tthe melt.the lactam containing 11,72% weight. lactamase sodium.
In a flask with a capacity of 0.25 l, equipped as in example 1, load 1.5 g of granulated potassium alkali, of 18.45 g of lactam and 30 ml of hexane. The mixture is heated, put in the course of the stirrer and intensive boiling fix the start of the reaction, those which the temperature is 63°C. As the alkali dissolution temperature rises to 97°C. the reaction Time to dissolve alkali 20-25 minutes Cooling the obtained product is accompanied by his first hypothermia to 50°C, followed by crystallization, during which the temperature rises to 54.5°C. the Color of the product is exclusively white. Sample solubility in water indicates the presence of small amounts of low molecular weight, water-soluble oligomers, giving the product flexibility, compactness and convenience for dosing (no dusting characteristic of the products subjected to recrystallization). Keep the catalyst in conditions that do not allow contact with the atmosphere. The oligomers contained in it, have a protective effect. Content lactamase potassium in the obtained catalyst 20,8%by weight.
In a flask with a capacity of 0.5 liters, equipped as in example 1, download 7.0 g of alkali sodium, 2.0 g potassium alkali and 32 g of lactam. Pour 150 ml of hexane. let the heater and stirrer. Reaction, marked by the beginning of the boiling azeotrope. starts at 69-70°C and proceeds very rapidly. Heat regulate thus, in order to prevent boiling of the mixture. As the dissolution of a mixture of alkali, the temperature is gradually raised to 80-85°C, and metallizovannyj lactam falls in the form of a fine dispersion in hexane. About the end of the reaction is judged to end ejecta the azeotrope. Get buttery product, beginning to harden at 40°C, and the temperature rises to 44°C. the Total content of metallizovannogo product in the dried sample is estimated at 75%.
1. The method of producing catalyst for the anionic polymerization of ε-caprolactam its direct interaction with the compound of the alkali metal in the presence of an aprotic solvent removed after completion of the reaction, wherein the reaction is carried out at temperatures below 60°C, as compounds of alkali metals are used hydroxides or combinations thereof, as an active diluents are aliphatic hydrocarbons having a number of carbon atoms in the range of 5-9 or mixtures thereof, forming a by product of the reaction, water heterogeneous azeotrope removed during the conversion.
2. The method according to claim 1, characterized in that the reaction is carried out preferably at a temperature of 60-100°C.
SUBSTANCE: invention relates to production of polyamide resins in powder form. Spheroidal particles of polyamide or copolyesteramide with average diametre between 460 and 100 mcm are obtained through polymerisation in a solvent. The reaction medium is mixed with mineral filler - silica with average particle diametre between 1 and 30 µm. Polyamide or copolyester amide is obtained in powder form. The obtained powder is used to make coatings, ink compositions, paint compositions, cosmetic compositions, pharmaceutical compositions and alloys with metal powder or metal oxide powder. The polyamide or copolyester amide powder is used to make articles through oligomerisation by melting using a laser beam (laser sintering), infrared or UV radiation.
EFFECT: invention enables to obtain polyamide powder in form of particles with grain-size composition with average diametre between 60 and 100 mcm.
18 cl, 15 ex, 1 tbl, 1 dwg
FIELD: organic chemistry, polymers, chemical technology.
SUBSTANCE: invention relates to a method for preparing polyamide that can be used as a structural material. Polyamide is prepared by co-polymerization reaction of ε-caprolactam and 1,6-hexamethylene diisocyanate in the mass ratio = (95-90):(5-10) in the presence of catalyst and an activating agent. As catalyst method involves using ε-caprolactam Li-salt and 2,4-toluylene diisocyanate as an activating agent. The process is carried out at temperature (180 ± 5)°C up to depletion of lactam cycles followed by heating the reaction mass for 2 h. Invention provides preparing polyamides with enhanced values of destroying stress (breaking point) and provides expanding assortment of methods providing preparing polyamides with different physical-mechanical properties also.
EFFECT: improved preparing method.
2 tbl, 4 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for preparing polyamide that can be used as a structural material. Polyamide is prepared by co-polymerization reaction of ε-caprolactam and 1,6-hexamethylenediisocyanate taken among the group of di-isocyanates or urethane prepolymer SKU-PFL-100 in the mass ratio = (95-90):(5-10) in the presence of catalyst and activating agent. As a catalyst method involves using ε-caprolactam Na-salts and 2,4-toluylenedi-isocyanate as an activating agent. The process is carried out at temperature (180 ± 5)°C up to depletion of lactam cycles followed by heating the reaction mass for 2 h. Invention provides preparing polyamides with enhanced values of destroying stress (breaking point) and to expand assortment of methods providing preparing polyamides with different physical-mechanical properties.
EFFECT: improved preparing method.
2 tbl, 10 ex
FIELD: organic chemistry, structural materials.
SUBSTANCE: claimed polyamide is obtained by copolymerization of ε-caprolactam and 2,4-toluylenediisocyanate in mass ratio of (95-95):(3-5) in presence of ε-caprolactam sodium salt at 180±5)°C up to exhausting of lactam cycles. Then reaction mass is heated for 2 h.
EFFECT: polyamides with increased elongation and failure stress; as well as with various physical and mechanical properties.
2 tbl, 8 ex
FIELD: chemistry of lactams' derivatives.
SUBSTANCE: the present innovation deals with obtaining N-(2-chloroalkyl)- and N-alkyl-aromatic derivatives of lactams of the following general formula: , where R=H, Cl, R'=(CH2)3, (CH2)5 which could be modifiers of unsaturated carbon-chain caoutchoucs and rubber mixtures based upon them. The suggested method for obtaining the mentioned N-substituted lactams deals with combining N-chlorolactams and allyl benzene, moreover, as N-lactams one should apply either N-chlorobutyrolactam or N-chlorocaprolactam. The process should be carried out at molar ratio of N-chlorolactam to allyl benzene being equal to 1-1.15:1, at availability of a catalyzer as mono-tertiary-butylperoxy-α-methylmethoxyethoxyethyl ether of ethylene glycol taken at the quantity of 0.4-4.0% weight, in the medium of inert solvent, for example, chlorobenzene at 100-125° C for about 15-20 min. The innovation enables to shorten terms of reaction by 20-30 times, simplify the way for obtaining target products and widen the assortment of the obtained compounds, as well.
EFFECT: higher efficiency.
SUBSTANCE: invention relates to the oil-refining and petrochemical industry and specifically to preparation of catalysts for heavy catalytic cracking of oil fractions for producing C2-C4 olefins and high-octane gasoline. The invention particularly relates to a microsphere cracking catalyst obtained from a suspension which contains, based on dry residue, 25-35 wt % fine zeolite ReHY, 30-40 wt % kaolin, 25-44 wt % aluminium oxide sources and 1-10 wt % fine silicon dioxide. The invention also relates to a method of producing a microsphere cracking catalyst, which includes steps of preparing a suspension of fine zeolite ReHY, kaolin, aluminium oxide sources and fine silicon dioxide with concentration of the suspension, based on dry residue, of 450-600 g/l, moulding by spraying the suspension in a medium of flue gases at temperature of 140-170°C and calcining the obtained microspheres at temperature of 550-650°C in a revolving calcining furnace.
EFFECT: obtaining a microsphere cracking catalyst with high wear-resistance and catalytic activity.
4 cl, 1 tbl, 5 ex
FIELD: process engineering.
SUBSTANCE: invention relates to production of metal-carbon-bearing bodies. Said bodies include ferromagnetic metal particles encapsulated with graphite carbon plies. This method comprises impregnation of cellulose, cellulose-like or carbohydrate boy or bodies produced by hydrothermal treatment with aqueous solution of at least one metal compound. Said metal or metals are selected from ferromagnetic metals or alloys. Then, impregnated bodies are subjected to thermal carbonisation by heating said bodies in inert atmosphere deprived, practically of oxygen at temperature over about 700°C. Now, the portion of at least one metal compound is reduced to appropriate metal or metal alloy.
EFFECT: production of catalytically active bodies.
15 cl, 8 dwg, 5 ex
SUBSTANCE: invention relates to catalysis. Described is an olefin polymerisation catalyst comprising: (I) a clad catalyst support comprising (a) a core which comprises alumina particles and (b) about 1-40 wt % silica, based on the weight of said cladding of the clad catalyst support on the surface of said core; said clad catalyst support having a BET surface area of not less than 20 m2/g; porosity of at least about 0.2 cm3/g; and a normalised sulphur uptake (NSU) value of up to 25 mcg/m2; and (II) 0.1-10 wt % , based on the weight of said catalyst, of catalytically active, with respect to olefin polymerisation, elemental transition metal, compound thereof, or complex thereof, wherein said transition metal is selected form Fe, Cr, Ti, Zr, Hf, Ni or mixture thereof, on the surface of said clad catalyst support. Methods of producing said catalyst and use thereof are described.
EFFECT: high catalyst activity.
21 cl, 2 dwg, 3 tbl, 12 ex
SUBSTANCE: invention relates to catalysis. Described are methods of preparing a catalyst precursor, the first preparation step of which involves impregnating catalyst support particles with an organic cobalt compound in an impregnating liquid to form an impregnated intermediate product, calcining the impregnated intermediate product at calcination temperature not higher than 400°C to obtain a calcined intermediate product; and the second preparation step of which involves impregnating the calcined intermediate product from the first step with an inorganic cobalt salt in an impregnating liquid to form an impregnated support and calcining the impregnated support to obtain a catalyst precursor, wherein neither of the inorganic cobalt salts used at the second preparation step is used at the first preparation step. Described is synthesis of hydrocarbons in the presence of catalysts obtained using said method.
EFFECT: high catalyst activity.
20 cl, 5 tbl, 11 ex
SUBSTANCE: present invention relates to a mesoporous carbon-supported copper-based catalyst, a method for production and use thereof in catalytic dehydrogenation of a compound with a C2-C12 alkyl chain to convert said compound to a compound with a corresponding alkenyl chain. The catalyst contains mesoporous carbon, a copper component and an auxiliary element supported on said mesoporous carbon. One or more auxiliary elements (in form of oxides) are selected from a group consisting of V2O5, Li2O, MgO, CaO, Ga2O3, ZnO, Al2O3, CeO2, La2O3, SnO2 and K2O. The amount of the copper component (calculated as CuO) is 2-20 wt % based on the total weight of the catalyst. The amount of the auxiliary element (calculated as said oxide) is 0-3 wt %. The amount of the mesoporous carbon is 77.1-98 wt % based on the total weight of the catalyst. The method of producing the catalyst involves: (1) a step of contacting a copper component precursor, auxiliary element precursor and mesoporous carbon in a given ratio to form an intermediate product and (2) a step of calcining the intermediate product to obtain the mesoporous carbon-supported copper-based catalyst.
EFFECT: catalyst is cheap, environmentally safe and has high thermal stability and caking resistance with considerably high and relatively stable catalytic activity.
19 cl, 47 ex
SUBSTANCE: invention relates to field of catalysis. Described is method of obtaining metal oxide on substrate, suitable for application as precursor for catalyst or sorbent, which includes the following stages: (i) impregnation of substrate material with metal nitrate solution in solvent, (ii) keeping impregnated material in gas mixture, containing nitrogen oxide, at temperature within the range to remove solvent from impregnated material with simultaneous drying and stabilisation of metal nitrate on substrate, with obtaining dispersed on substrate metal nitrate and (iii) calcination of dispersed on substrate metal nitrate to realise its decomposition and formation of metal oxide on substrate, where calcinations is performed in gas mixture, which consists of one or several inert gases and nitrogen oxide, and concentration of nitrogen oxide in gas mixture is within the range 0.001-15 vol.%.
EFFECT: increased catalytic activity of obtained products.
12 cl, 4 dwg, 11 tbl, 8 ex
SUBSTANCE: invention relates to field of catalysis. Described is method of obtaining catalyst, which includes impregnation of metal oxide substrate material with platinum compound, drying below the point of said platinum compound decomposition, burning in gas flow, which contains NO and inert gas. Described is application of said catalyst as oxidation catalyst, and catalyst unit in the system of exhaust gas purification.
EFFECT: increased activity and selectivity of CO and NO oxidation.
17 cl, 3 dwg, 1 tbl, 6 ex
SUBSTANCE: invention relates to field of catalysis. Described is method of creating efficient platinum-free catalytic coating on ceramic units for neutralisation of waste gases of autotractor diesel engines, which includes formation of substrate with large value of specific surface on ceramic honeycomb carriers.
EFFECT: increase of catalyst activity.
2 cl, 4 dwg, 2 tbl, 1 ex
SUBSTANCE: described are methods of chrome catalyst activation, which include increasing chrome catalyst temperature in, at least, bilinear changing, which contains increase of chrome catalyst temperature at first speed during first period of time to first temperature on first site of changing of bilinear changing; and increase of chrome catalyst temperature at second speed during second period of time from said first temperature to second temperature on second site of changing of bilinear changing, which follows directly after first area of changing, and first speed is larger, than second speed, and first period precedes second period; with first temperature being in the range from approximately 650°C to approximately 750°C, with second temperature being in the range from approximately 750°C to approximately 850°C. Method of obtaining polyolefines in presence of catalyst, activated by claimed method, is described.
EFFECT: increased efficiency of catalyst activation.
19 cl, 13 dwg, 17 tbl, 1 ex
SUBSTANCE: described is a catalyst for selective oxidation of carbon monoxide in a mixture with ammonia, containing 0.7-1.2 wt % gold, 0.8-5.0 wt % Fe3+ and a crystalline theta-modification of aluminium oxide (θ-Al2O3) - the balance. Described are methods of producing said catalyst.
EFFECT: obtaining a catalyst with high activity and selectivity in oxidation of CO while reducing activity in ammonia conversion.
3 cl, 1 tbl, 10 ex