Material for production of the catalyst carrier with the high oxygen capacity (versions)and the method of its manufacture

FIELD: chemical industry; materials and the methods for the catalyst carrier manufacture.

SUBSTANCE: the invention is pertaining to the new mixed oxides produced from ceric oxide and zirconium oxide, which can used as the catalyzers or the catalyzers carriers for purification of the combustion engine exhaust gases. The mixed oxide possesses the polyphase cubical form of the crystallization and oxygenous capacity of at least 260/ micromoles of O2 /g of the sample and the speed of the oxygen extraction of more than 1.0 mg-O2/m2-minute, which are measured after combustion within 4 hours at the temperature of 1000°C. The invention also presents the substrate with the cover containing the indicated mixed oxide. The method of production of the polycrystallic particles of the indicated mixed ceric-zirconium oxide includes the following stages: i) production of the solution of the mixed salt which are containing, at least, one salt of cerium and, at least, one salt of zirconium in the concentration, sufficient for formation of the polycrystallic particles of the corresponding dry product on the basis of the mixed oxide. At that the indicated particles have the cerium-oxide component and zirconium-oxide component, in which these components are distributed inside the subcrystalline structure of the particles in such a manner, that each crystallite in the particle consists of a set of the adjacent one to another domains, in which the atomic ratios of Ce:Zr which are inherited by the adjacent to each other domains, are characterized by the degree of the non-uniformity with respect to each other and determined by means of the method of the X-ray dissipation the small angles and expressed by the normalized intensity of the dissipation I(Q) within the limits from approximately 47 up to approximately 119 at vector of dissipation Q, equal to 0.10 A-1; ii) treatment of the solution of the mixed salt produced in compliance with the stage (i),with the help of the base with formation of sediment; iii) treatment of the sediment produced in compliance with the stage (ii),using the oxidative agent in amount, sufficient for oxidizing Ce+3 up to Ce+4; iv) washing and drying of the residue produced in compliance with the stage (iii); and v) calcination of the dry sediment produced in compliance with the stage (iv),as the result there are produced polycrystallic particles of the oxide of ceric and zirconium in the form of the mixed oxide with the above indicated characteristics. The technical result is the produced mixed oxide possesses both the high oxygenous capacitance, and the heightened speed of the oxygen return in the conditions of the high temperatures.

EFFECT: the invention ensures production of the mixed oxide manufactured from ceric oxide and zirconium oxide and possessing the high oxygenous capacitance and the heightened speed of the oxygen return in the conditions of the high temperatures.

68 cl, 21 ex, 2 dwg

 

The technical field to which the invention relates.

The present invention relates to new compositions based on mixed oxides of cerium oxide and zirconium oxide having a high oxygen storage capacity. The present invention relates also to the preparation of mixed oxide compositions and to the method of application of the compositions of mixed oxides as catalysts and/or carriers of catalysts, in particular for cleaning and/or conversion of exhaust gases of internal combustion engines.

Prerequisites to the creation of inventions

The cerium oxide is widely used as a promoter and a catalyst for purification of exhaust gases emitted by the internal combustion engine, due to its high oxygen storage capacity. Usually with the aim of increasing oxygen capacity (EC) of the cerium oxide is used in the form of small particles having relatively high specific surface area. Unfortunately, however, the cerium oxide has a tendency to specalise with decreasing surface in conditions of high temperatures, losing as a result of its effectiveness as kislorodnogo component.

Later the need to thermally stabilize the catalysts based on cerium oxide for high temperatures focused on the doping of cerium oxide wide range of metal oxides. To this end, many related to the old technique of literary sources was proposed in the cerium oxide, zirconium oxide, or other oxides of rare earth elements in order to reduce the sintering process and the creation of materials with a large value surface. For example, in Japanese patent application 55,15/1992 discloses a method of preparation of a mixed oxide of cerium and zirconium oxide, in which a solution containing a salt of trivalent cerium, zirconium salt, is subjected to the coprecipitation using any base in the presence of hydrogen peroxide. The method gives mixed oxides of cerium and zirconium, having a high specific surface area and excellent heat resistance.

It was also suggested that pure solid solutions of cerium oxide and zirconium oxide having a large amount of surface, have been used as an effective kislorodchiki components in automotive catalytic converters. Published reports of various compositions of cerium oxide to zirconium oxide.

For example, in U.S. patent 5693299 revealed a mixed oxide of cerium oxide and zirconium oxide having a thermal stability and a very high specific surface area equal to at least 80 m2/year of Mixed oxides are obtained using a high-temperature hydrolysis and have a clean monophasic cubic form crystallization SEO2where Zirconia embedded in crystalline form of silicon oxide.

In U.S. patent 5607892 disclosed particles mixed zerava-zirconium mixed oxide with a stable specific surface area. Mixed xidi receive thorough mixing Zola Zirconia by Sol of cerium, deposition of the mixture using a Foundation with the aim of obtaining sediment and subsequent calcination of the resulting sludge. It was reported that the oxygen storage capacity measured at the product calcined at 1000°is only 2.8 ml CO/g CeO2(62,5 μmol O21 g CeO2).

In order to meet future stringent standards on emissions need to catalysts based on cerium oxide has a high oxygen storage capacity even after exposure to temperatures in excess of 1000°C. As catalysts on the basis of cerium oxide subjected to such high temperatures, usually decreases the surface, there is a need to develop materials based on cerium with an oxygen tank, independent of the values of the surface.

Next, thanks to recent advances in control technology for the engines of the latest engines have even tighter control of the composition of the fuel-air mixture caused by rapid changes in the partial pressure of oxygen in place of the catalyst. The catalysts used in these engines, should not only have a higher oxygen capacity compared with previously known catalysts, but high upload speed of oxygen in order to respond to these fluctuations partial pressure is I oxygen. Consequently, in the automotive industry there is a need for materials of catalysts and catalysts carriers, which would have as high oxygen storage capacity, and increased upload speed of oxygen at high temperatures.

Summary of invention

Developed new compositions based on mixed oxides of cerium and zirconium with extremely high oxygen storage capacity and the ability of oxygen. Mixed oxides of cerium and zirconium according to the invention have nominally cubic, multiphase form of crystallization, based on uniformly regulated domain crystalline substructure. Unexpectedly it turned out that the corresponding present invention the composition of mixed oxides have a high oxygen storage capacity, independent of the values of the surface.

The composition of the mixed oxides according to the invention contain polycrystalline particles based on cerium oxide and zirconium oxide. The crystallites comprising polycrystalline particles consist of areas or "domains", subcritical level with different ratios of cerium and zirconium. In accordance with the present invention it was found that when the adjacent one to the other domains within the same crystallite vary considerably atomic ratio is enemy of cerium and zirconium, there is a unique crystalline substructure, which helps to increase oxygen capacity and oxygen recoil.

Without intending to go into any specific theory, it is possible to predict that the reason that the adjacent one to the other domains have different lattice parameters, is the difference in composition between adjacent domains. It is assumed that the difference in lattice parameters leads to local stress at the boundaries between domains. It is hypothesized that such local voltage along the boundaries between adjacent domains creates a network of local routes through the crystallites. It is assumed that the existence of such paths allows oxygen to quickly penetrate into the crystal lattice and quickly to get out of it, thereby providing increased oxygen capacity and oxygen returns that are not dependent on surface area of the particles.

In connection with the foregoing, the main advantage of the present invention is that it provides new compositions of cerium oxide and zirconium oxide having a specific domain crystal structure, which contributes to increased oxygen capacity and upload speed of oxygen compared with the existing compositions of cerium oxide and zirconium oxide.

Another advantage of the present invention are the two which is the fact that it offers new compositions of cerium oxide and zirconium oxide, which have high oxygen capacity, independent of the values of the surface.

An advantage of the present invention is that it provides compositions of cerium oxide and zirconium oxide having a high oxygen storage capacity, and in these compositions is not required, which is still considered necessary, clean single-phase cubic solid solution or cerium oxide dissolved in the zirconium oxide or zirconium oxide dissolved in the cerium oxide.

Another advantage of the present invention is that it offers a new mixed oxides of cerium and zirconium, which are highly effective as a catalyst/carrier for purification of exhaust gases.

Finally, another advantage of the present invention is that it provides a method of preparation and application of new compositions of cerium oxide and zirconium oxide.

Other advantages and objects of the present invention will be demonstrated in the description, examples and claims.

Brief description of drawings

Figure 1 is a plot of the normalized scattering intensity I(Q) in the range of 0 to 12 from Q in the range from 0.0 to 2.5 Å-1determined using the method of scattering Ren is ganovski rays at small angles (SAXS) for compositions of cerium oxide and zirconium oxide, prepared in accordance with example 1(•), comparative example 1(▴) and sravnitelnim example 2(f), (graph) shows the position of the first diffraction peak at Q, is 2.06 Å-1by which the normalized scattering intensity.

Figure 2 is a plot of the normalized scattering intensity I(Q) in the range from 0 to 200 from Q in the range from 0.0 to 0.15 Å-1determined using the method of x-ray scattering at small angles (SAXS) for compositions of cerium oxide and zirconium oxide, prepared in accordance with example 1(•), comparative example 1(▴) and comparative example 3(f).

Detailed description of the invention

Hereinafter the present invention will be explained in detail.

Used herein, the term "oxygen tank" (KE) refers to the quantity contained in a sample of oxygen determined by measuring the mass loss using conventional thermogravimetric analysis (TGA). The sample was incubated for 60 min at 500°With the current of air moving with a bulk velocity of 120 ml/min, until complete oxidation of the sample. After that the air flow is immediately replaced by a mixture of 10% N2in nitrogen at the same temperature and flow rate and maintained at a constant temperature for an additional 60 min Oxygen capacity is predelay measurement of mass loss during the transition from oxidative conditions for recovery. The unit used to characterize KE is μmol O21 g of the sample.

Used herein, the term "upload speed of oxygen" refers to the rate at which oxygen is released from the particles of the Ce/Zr measured using TGA. The sample was incubated for 60 min at 500°in the stream of air moving with a bulk velocity of 120 ml/min, until complete oxidation of the sample. After that the air flow is immediately replaced by a mixture of 10% H2in nitrogen at the same temperature and flow rate and maintained at a constant temperature for an additional 60 minutes upload Speed of oxygen calculated by the curve of the first derivative of the weight loss from the time and then normalize by the size of the surface of the particles. The unit used to characterize the upload rate of the oxygen is mg-O2/m2-minutes

Used herein, the term "polycrystalline particle" means a particle comprising of more than two crystallites on the basis of the measurements made using the traditional method of x-ray diffraction.

Used herein, the term "crystalline" refers to the area inside the particles having the same crystallographic orientation and the structure defined by the broadening of the lines using the traditional method of x-ray diffraction.

Used herein, the term "the omen" means the area or volume within a single crystal, having a homogeneous or substantially homogeneous composition is determined using the method of x-ray scattering at small angles (SAXS). According to the present invention the ratio of Ce:Zr in the domain is regulated so that it differed from that relationship in the neighboring domains, containing the crystallite.

Used herein, the term "subcriteria structure" refers to the area inside the crystal, which consists of two or more domains.

Used herein, the term "multi-phase" refers to a material that contains more than one crystalline phase. This phase may consist of more than one crystal structure, for example, cubic or tetragonal, or from the same structure but different lattice parameters.

Used herein, the term "heterogeneity" refers to the adjacent one to the other domains within a single crystal having different atomic relations of Ce:Zr.

Used herein, the term "value of the surface" means the surface area of the particles, measured using a standard analysis of the BET.

Used herein, the term "aging" refers to the heating of the sample to accelerate change its properties.

Used herein, the term "normalized scattering intensity I(Q)" indicates the intensity of the scattering is defined using meth is Yes x-ray scattering at small angles (SAXS) and divided by a constant, such as intensity, integrated under the first diffraction peak with center at Q, is approximately equal to 2.06 Å-1adopted per unit.

Composition of mixed oxides in accordance with the present invention are multi-phase crystalline structure and is formed of polycrystalline particles. Each particle has a component of cerium oxide and a component of zirconium oxide and is composed of many crystallites. Each crystallite in the particle consists of subcritically structure, which contains a number of domains with different atomic ratio of Ce:Zr in the neighboring domains, characterized by a given degree of heterogeneity with respect to one another, determined by the method of x-ray scattering at small angles (SAXS). It is easy to understand that the measurement using SAXS is carried out on multi-particle sample, and the obtained data are the average of the distribution of the degree of heterogeneity between domains on subcritical level of particles in the sample. Thus, the SAXS data indicate that the individual particles must contain the structure above the average.

According to the invention, the average size of the domains in the freshly prepared material is from about 10 to about 50 Å. After aging for 5 hours at 1000°With the average size of the domains, a modification of the t is from about 10 to 50 Å .

Domains distributed inside the grains of cerium oxide and zirconium oxide having an average size of from about 40 to about 200 Åmainly from about 50 to 120 Åthat it can be easily determined using x-ray diffraction using the peak at 28-30° 2Θ after calcination for 4 hours at 900°C. the Crystallites, in turn, form polycrystalline particles with an average particle size ranging from about 0.1 to about 50 μm, mainly from about 0.5 to 20 μm

Typically, particles of mixed oxides of the present invention contain from about 80 to 20 wt.%. CeO2and from about 20 to 80 wt.%. ZrO2mainly from about 40 to 60 wt.%. SEO2and from about 60 to 40 wt.%. ZrO2. In a preferred embodiment, the mixed oxide composition comprises 50 wt.%. CeO2and 50% wt. ZrO2. In the optimal case, particles of mixed oxides of the invention can include up to about 10 wt.%, mostly up to 8% wt. and, most preferably, from about 2 to about 7% wt. additional metal oxide other than cerium. Suitable metal oxides include, but are not limited to, oxides of rare earth metals other than cerium, calcium oxide and mixtures thereof. Suitable oxides of rare earth metals include, but are not Ogre is nicely them the oxides of lanthanum, praseodymium, neodymium, samarium, gadolinium and yttrium.

Typically, the compositions of the mixed oxides of the invention have a specific surface after calcination for 2 hours at 500°equal to at least 30 m2/g, preferably at least 40 m2/g and even more preferably at least 60 m2/g, which usually ranges from about 30 to about 120, mainly from about 40 to about 100 and most preferably from about 50 to 90 m2/g After aging for 4 hours at 1000°With the value of specific surface area does not exceed 10 m2/g, mostly less than 5 m2/g and, most preferably, not more than 3 m2/g, usually being in the range from about 10 to about 1, mainly from about 5 to about 1 and most preferably from about 3 to about 1 m2/year

Mixed oxides of the present invention have the advantage that they simultaneously have a high upload speed of oxygen and high oxygen capacity. Mixed oxides of the present invention typically have an oxygen capacity, measured isothermal at 500°equal to at least 260 μmol O2/g of the sample, mainly over 300 μmol O2/g of the sample, more preferable 315 μmol O2/g of the sample and n is the most preferable, more than 330 μmol O2/g of sample after aging for 4 hours at 1000°C. Usually mixed oxides of the invention have the KE in the range from about 260 to about 800, mainly from about 300 to about 600, and most preferably, from about 350 to about 450 μmol O2/g of sample after aging for 4 hours at 1000°C.

Mixed oxides of the present invention have a high upload speed of oxygen, which after aging for 4 hours at 1000°usually above 1.0 mg-O2/m2-mines, mostly above 2.0 mg-O2/m2-min and most preferably above 5.0 mg-O2/m2-minutes Usually mixed oxides after aging for 4 hours at 1000°To have the upload speed of oxygen in the range from about 1 to about 100, mostly from about 2 to about 50 and most preferably from about 5 to about 10 mg-O2/m2-minutes

Increased oxygen capacity and oxygen returns, which have compositions of cerium oxide and zirconium oxide of the invention are achieved by adjusting the difference in the composition of atomic relations of Ce:Zr adjacent one to another domain monocrystalline so that in these domains were created with different lattice parameters. It is easy to see specialists, some domains will be when this obog is on cerium oxide, i.e. will consist mainly of cerium oxide to zirconium oxide dissolved in the silicon oxide, while the other domains will be enriched with zirconium oxide, i.e. are composed mainly of zirconium oxide with cerium oxide dissolved in the zirconium oxide. However, if the compositions of the neighboring domains too uniform or too heterogeneous, mixed compositions will not form a domain structure required to provide the desired oxygen capacity and efficiency of oxygen. Thus, the degree of difference in the composition or homogeneity between neighboring domains is important for obtaining compositions with high oxygen storage capacity and at the same time with high upload speeds oxygen-dependent values of the surface.

The degree of differences in the composition of neighboring domains can be, as described below, determined using SAXS method.

While the task of the traditional method of scattering of x-rays is the determination of the crystal structure and positions of the atoms, to measure the SAXS method is to study the peculiarities of the local structure on a scale greater than the atomic distance, usually at the scale of tens to hundreds of angstroms. The scattering angle 2Θ between the incident beam and the detector is correlated with the scattering vector Q as Q=(4π/λsiΘ where λ is the wavelength of x-ray radiation. The value of the scattering vector Q determines the characteristic length, which examined using x-rays as π/Q. When measuring the intensity of x-ray diffraction under smaller angles, i.e. at smaller scattering vectors Q, you can explore spatial structural features of the materials. In order to avoid interference between the incident beam and the intensity of the scattering of x-rays, which is measured under a very small angle, SAXS method requires very strict conditions collimate the incident beam. Thus, the measurement using SAXS cannot be made on a standard x-ray diffractometer. However, for the measurements described in this patent, it is necessary to measure the intensity of the scattering at a relatively large angles to normalize the intensity that will be explained in detail below. The ideal means to achieve the above mentioned purpose is synchrotron x-ray radiation, because of its high intensity of the incident beam with a low divergence beam facilitates the collimation, thus allowing to measure the intensity of the scattering of x-rays over a wide range of angles and minimizing the time of measurement.

Described here, the measurement method SAXS were the imp is tive on beam line X-7A National synchrotron light source in Brokhavensky national laboratory, Upton, New York. The incident x-rays with a wavelength of λ=0,912 Å was irradiated materials sample, wrapped in a thin layer of Canton is a very transparent with respect to x-rays polymer material. The typical thickness of the samples was in the range of from 10 to 100 μm the scattering Intensity was measured using a standard detector for angles 0,66°<2Θ<to 25.15°, which corresponds to Q in the range from about 0.08 to Å-1to about 3,0 Å-1. Incident x-ray beam was kollimalai so that the contribution of the incident beam in the scattering intensity, measured at the smallest angle 2Θ=0,66°With, was negligible. The scattered intensity of x-rays were collected at each measurement point in a few seconds.

The intensity of the SAXS method from systems with separation of the phases is subject to the Porod law:

where I(Q) is the normalized intensity of the scattering. Figure 1 is a graph of the normalized scattering intensity I(Q) from the scattering vector Q detects the first diffraction peak, centered about Q, is approximately equal to 2.06 Å-1that was normalized scattering intensity.

In equation (1) is determined by equation (2):

where Δρ eating is the difference in electron density between the two phases and S - the area of the boundary surface between the phases measured in units Å2. At a given value of S, the value of I increases with Δρthat in the case of mixed oxide (Ce, Zr)O2is primarily due to the difference between domains within the crystal. If we consider a two-phase sample compositions (Ce1-X2ZrX1)O2in one phase and (Ce1-X2ZrX2)O2in another, a Δρ equal 0,49(X1-x2), then the intensity value at a particular Q is a measure of the heterogeneity of composition.

Logarithmic graph of equation (1) is a straight line described by equation (3):

Thus, for scattering intensities collected from different samples and normalized in the same way, the angle of slope of the resulting straight lines is equal to -4, while the clip on the coordinate of the segment depends on the settings Δρ and S.

To determine the degree of heterogeneity within subcritically domain structure of mixed oxides of the present invention, the measurement method for SAXS scattering vectors Q in the range from about 0.08 to Å-1to about 3,0 Å-1. Then build a graph of the normalized scattering intensity 7(Q) of the scattering vector Q, as indicated above (in units  -1), and not on 2Θas is usually done.

Relevant to the present invention mixed oxides have a critical degree of heterogeneity, when they are characterized by a normalized scattering intensity I(Q) in the range from about 49 to about 119, mainly from about 50 to about 100, and most preferably, from about 54 to about 85 in the scattering of Q equal to 10 Å-1. Typically, the angle of inclination of the straight part of the graph of dependence of the logarithm of the normalized intensity of the scattering LnI(Q) from the logarithm of the scattering vector ln(Q) when -2,5<ln(Q)<-1 is approximately equal to-4.0 and, thus, subject to the Porod law. Specialists are well aware that the SAXS data, which correspond to the Porod law, to the greatest extent indicate the desired domain structure.

According to the present invention mixed oxides are usually prepared by co-deposition of a solution of mixed salts containing a salt of cerium, zirconium salt, dissolved in a suitable solvent, e.g. in water or an organic solvent. In one of the preferred options the solvent is water.

The concentration of solid materials in solutions of mixed salts used to prepare the mixed oxide of the present invention is significant. If the concentration of the solid who's material is too low, subcriteria structure having the desired degree of heterogeneity, to be formed will not be. In this regard, the content of solid material in the solution is regulated to ensure the desired level of heterogeneity. Usually the solution is mixed salt has a concentration of solid materials, which is sufficient to facilitate formation of the desired domain structure. Preferably, the solution is mixed salt has a concentration of solid materials above about 23 wt.%, more preferably above about 25 wt.%. and, most preferably, above about 27 wt.%. calculated on oxide basis. Typically, the concentration of solid material in the solution of mixed salts is in the range from about 24 to about 39 wt.%. and preferably from about 25 to about 29% wt. calculated on oxide basis.

Solutions of mixed salts used for preparation of mixed oxides in accordance with the present invention, can be prepared by mixing a cerium salt with zirconium salt such manner and under such conditions that would ensure dissolution of all or almost all of the content of solid materials in a suitable solvent. In one embodiment, the solution of the mixed salts is prepared by mixing a cerium salt with an aqueous solution of zirconium salt in which the molar ratio of cation to anion is usual ranges from 1:1 to 1:2. For example, when zirconium salt is xinitrc zirconium molar ratio of cation to anion in the solution of zirconium salt is usually 1:2. On the other hand, when the zirconium salt is hydroxylated zirconium molar ratio of cation to anion in the solution of zirconium salt is usually 1:1.

In another embodiment of the invention the solution of the mixed salts is prepared by dissolving carbonate of cerium zirconium salt solution to obtain a solution in which the molar ratio of cation to anion is 1:2, and then adding to the solution a minimum amount of acid sufficient to dissolve all or almost all of carbonate, as evidenced by light or a clear solution.

Suitable cerium and zirconium salts, which can be used to prepare solutions of mixed salts, applicable for the method of the present invention include (but are not limited to, nitrates, chlorides, sulfates, carbonates, etc. To the solution of mixed salts can be added for more oxide components, i.e. alloying components, in any soluble form.

Precipitation from a solution of mixed salts can be made by treatment of a solution in any basis, mainly ammonia, while stirring, resulting in a precipitate falls corresponding to hydroxid. the pH of the solution during the deposition is alkaline, for example, typically in the range of approximately 8 to 11.

Following the deposition of the precipitate is treated with an oxidizing agent in a quantity sufficient to completely or substantially oxidize present CE+3to Ce+4. Suitable oxidizing agents include (but are not limited to) an aqueous solution of bromine, hydrogen peroxide, sodium bromate, sodium hypochlorite, ozone, chlorine dioxide, etc. Preferred oxidizing agent is hydrogen peroxide. Usually the residue treated with an aqueous solution of hydrogen peroxide in a quantity sufficient to provide a molar ratio of hydrogen peroxide to Behold usually from about 0.25 to about 1. Preferably, an aqueous solution of hydrogen peroxide was diluted hydrogen peroxide containing less than about 35 wt.%. the hydrogen peroxide. Usually diluted hydrogen peroxide is added in a quantity sufficient to provide a molar ratio of hydrogen peroxide to Behold from about 0.5 to about 1.

It is desirable that the temperature when carrying out the stages of deposition and oxidation does not exceed 80°With mostly 70°and, most preferably, 60°C. In the preferred embodiment of the invention, the temperature in carrying out the stages and the deposition and oxidation will usually lie in the range from about 20 to about 70° With and preferably from about 30 to about 60°C. After the deposition of the precipitate may be subjected to aging at a temperature of typically from about 70 to 100°C for from about 30 minutes to about 5 hours.

The formed precipitate is filtered off and then washed with water, receiving the filter cake. The cake is dried in the traditional way by getting a free-flowing powder. In a preferred embodiment, the washed precipitate is re-suspended in water and the resulting suspension is subjected to spray drying. After that, the dried precipitate is calcined at a temperature of from approximately 500 to approximately 600°With the passage of time from about 30 minutes to about 3 hours, mostly from about 1 to about 4 hours and, most preferably, from about 2 to about 3 hours with the formation of a mixed oxide in accordance with the present invention.

To the mixed oxide can be added alloying component. If it alloying component can be added at any point in the preparation of mixed oxides. Preferably the addition of the alloying component after deposition, before or after calcination of the mixed oxide. Suitable alloying components include transition metals of group VIII in the form of oxides, salts, etc. as alloying components of the preferred Nickel, palladium and platinum, and the most preferred palladium and platinum. Usually alloying components added in quantities sufficient to create their concentration in the final product of mixed oxides from about 15 to about 1000 ppm by weight of the mixed oxide. The alloying component is preferably added in order to facilitate testing.

To obtain the desired particle size of the calcined mixed oxide can then be ground using a grinding drum type. Appropriate ways of grinding include (but are not limited to grinding on high-performance ball mill, grinding mill type Spex, the grinding energy to the liquid, etc.

Increased oxygen capacity and upload speed of oxygen compositions of mixed oxides of the present invention allow to use them in numerous areas. In particular, mixed oxides of the invention are well suited for use in the field of catalysis as catalysts and/or carriers of catalysts. In one of the preferred variants of the composition of mixed oxides according to the invention are used as components of the catalyst for purification or conversion of the exhaust gases emitted by internal combustion engines. In the event of such application to the compositions of the mixed oxides is usually mixed into aluminum oxide before or after impregnating the catalytically active elements, such as blagar the derivative metals. Such mixtures then either shape with the formation of the catalyst, for example, the form of beads or these mixtures are used for the formation of coatings for refractory materials, such as monolithic ceramic or metal, and such coverage is in itself known in the technique as "wash lining", described for example in U.S. patents 5491120, 5015617, 5039647, 5045521, 5063193, 5128306, 5139992 and 4965245 (called links included in the application as reference material).

To further illustrate the present invention and its advantages, the following specific examples. However, it should be borne in mind that the invention is not limited to the examples private parts.

All parts and percentages in the examples as well as in the rest of the description, unless otherwise stated, expressed in mass.

Further, any number limits mentioned in the description or the claims, such as limits representing a specific set of properties, units of measure, conditions, physical States or percentage grades, designed for accurate and specific submission, linking or any other manner, any number that is included in these limits, including the subset of numbers that are included in these limits.

EXAMPLES

Referred to in the examples of the oxygen capacity (KE) was determined by measuring the loss of the assy using conventional thermogravimetric analysis. The samples were kept for 60 min in a stream of air at 500°With a view to their complete oxidation with subsequent switching to the mixture with 10% H2nitrogen and isothermal exposure for an additional 60 min Oxygen capacity was determined by the mass loss during the transition from oxidative conditions for recovery.

All mentioned in the examples, the upload rate of oxygen were determined by calculating the first derivative of the dependence of the mass change from time schedule measurement of KE and the normalization of its largest sample surface.

Example 1

586 g of cerium carbonate (III) (49,5% oxide) dissolved in 1105 g of 20%aqueous solution zirconyl-nitrate and 310 g of concentrated nitric acid. The resulting solution contains 26,7% wt. solid materials in the form of oxides. The solution is stirred overnight to dissolve the carbonate. 93 g of this solution is poured into 400 ml of a 5 n solution of ammonia at a temperature of 40°and With stirring. The pH after adding the total amount is equal to approximately 9. The suspension is stirred for 30 min at 40°With, then added 52 g of 3%aqueous hydrogen peroxide solution. The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25.

The precipitate is washed with 5 volumes of hot deionized water. From the precipitate washed ammonium nitrate to a conductivity below 5 m Cm/see

Filter the roll cake is diluted with water in ratio 1:1 with the formation of the aqueous suspension, which is subjected to spray drying, receiving the powder. The dried powder is calcined for 1 hour at 500°getting to the final composition of mixed oxides containing 42 wt.%. zirconium oxide and 58% wt. cerium oxide. The powder is analyzed by the method of the scattering of x-rays at small angles (SAXS). The powder is characterized by a normalized scattering intensity I(Q)equal to 0,57 when Q=0,1 Å-1as shown in figure 2. A plot of the normalized scattering intensity I(Q) of Q is presented in figure 1.

To measure KE calcined powder of mixed oxides impregnated with 15 ppm of palladium in aqueous nitrate solution and calcined at 500°C. the Powder is subjected to aging for 4 hours at 1000°and measured EC using the above TGA. The magnitude of the surface after aging 1.0 m2/g, the oxygen capacity (KE) 363 μmol O2/g of the sample and the upload speed of the oxygen - 1.8 mg-O2/m2-minutes

Example 2

Get the filter cake with the use described in the example 1 procedure, except that, when the pellet is diluted with water in ratio 1:1 with the suspension, before spray drying the suspension add 15 ppm of palladium in aqueous nitrate solution. The dried powder is calcined for 1 hour at 500°C. the Powder was subjected to the Ute aging for 4 hours at 1000° With and measured EC using the above TGA. The magnitude of the surface after aging 1.0 m2/g, the oxygen capacity (KE) - 376 μmol O2/g of the sample and the upload speed of the oxygen - 7.5 mg-O2/m2-min Intensity normalized scattering I(Q) at Q=0,1 Å-1equal to 57.

Example 3

586 g of cerium carbonate(III) (49,5% solid material) is dissolved in 1105 g of 20%aqueous solution zirconyl-nitrate (20% wt. solid material) and 310 g of concentrated nitric acid. The solution mixed oxide contains 26.7% of solid materials. 93 g of this solution is subjected to precipitation in 400 ml of 5 n aqueous ammonia at 60°C. After 30 min stirring to a suspension add 1000 ml of 3%aqueous hydrogen peroxide solution. The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25.

The suspension is filtered and washed precipitate 3 l of deionized water at 70°C. the Filter cake is re-suspended in water and add 15 ppm Pd in the form of nitrate with the formation of the final mixed oxide with 15 ppm Pd. The resulting mixture was subjected to spray-dried and calcined for 1 hour at 500°C. the Final composition contains 42% by weight. zirconium oxide and 58% wt. cerium oxide.

The powder is subjected to aging for 4 hours at 1000°C. Recovering at 500°using TGA gives KE equal to 342 &x003BC; mol O2/g sample, and the upload speed of the oxygen - 1.9 mg-O2/m2-min Normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 70.

Example 4

Get the filter cake with the use described in example 3, procedure, except that the water filtered cake before spray drying alloyed 100 g/Pd million in the form of nitrates. Dried spray powder calcined and age as in example 3. The scattering intensity was equal to 69 when Q=0,1 Å-1, KE is equal to 350 mmol O2/g of the sample and the upload speed of the oxygen - 50.5 mg-O2/m2-minutes

Example 5

Get the filter cake with the use described in example 3, procedure, except that an aqueous filter cake before spray drying alloyed 1000 ppm of nitrate. Dried spray powder calcined and old, as in example 3. The intensity of the normalized scattering I(Q) at Q=0,1 Å-1equal to 69, KE is equal to 308 μmol O2/g sample, and the upload speed of the oxygen - 1.2 mg-O2/m2-minutes

Example 6

The solution of mixed nitrates receive, connecting 930 g of an aqueous solution of cerium nitrate (III) (28.3% of oxide) and 900 g of an aqueous solution of hydroxynitrile zirconium with respect to Zr:NO3approximately 1:1 (25,3% wt. oxide). The mixed solution contains 26,8% wt. the solid materials based on oxide. The final oxide composition contains 52,5% wt. CeO2and 47,5% wt. ZrO2.

The solution is added to 8 l 5 n solution of ammonia at 40°C. Precipitated precipitated hydroxide is treated with 1000 ml of 3%aqueous hydrogen peroxide solution.

The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25. The filter cake is re-suspended in water and add 15 ppm Pd in the form of nitrate. The resulting mixture was subjected to spray-dried and calcined for 1 hour at 500°C. the Calcined powder is subjected to aging for 4 hours at 1000°With, then measure present in the sample of oxygen at 500°using gravimetric device. KE equal 379 μmol O2/g sample, and the upload speed of the oxygen - 14,23 mg-O2/m2-min Normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 55.

Example 7

The solution of mixed nitrates produced by mixing 633 g of cerium carbonate (III) (55% oxide)dissolved in 570 g of 70%nitric acid with 142 g of deionized water with formation of a solution of nitrate of cerium (III) with 29% wt. solid materials. The solution is mixed with 965 g of an aqueous solution of hydroxynitrile zirconium (26,1% wt. oxide) with the ratio of Zr:NO3approximately 1:1. The concentration of the solution of mixed nitrates is 27.7% wt. oxide solid materials. End oxida the composition contains 58.9% of wt. CeO2and 41.2% wt. ZrO2. The solution is added to 8 l 5 n solution of ammonia at 40°and With stirring. Precipitated precipitated hydroxide is treated with 1000 ml of 3%aqueous solution of hydrogen peroxide (H2O2/CeO2=0.25 M), then filtered and washed from ammonium nitrate. The filter cake is re-suspended in water and alloyed 15 ppm Pd in the form of nitrate. The suspension is spray dried and calcined for 1 hour at 500°C. After aging powder for 4 hours at 1000°measured KE of the sample at 500°using gravimetric device is equal to 377 μmol O2/g sample, and the upload speed of the oxygen - 7.5 mg-O2/m2-min Normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 77.

Example 8

The solution of mixed nitrates produced by mixing of 67.1 g of an aqueous solution of cerium nitrate (III) (28% oxide) 22.6 g of an aqueous solution of hydroxynitrile zirconium with respect to Zr:NO3approximately 1:1 (26,1% wt. oxide) with the formation of the final solution of mixed nitrates concentration of 27.5% wt. solid materials based on oxides. The final oxide composition comprises 70 wt.%. CeO2and 30% wt. ZrO2. The solution is added to 400 ml of a 5 n solution of ammonia at 40°C and stirred for 30 minutes, Dropped to precipitate the hydroxide is treated with 6.25 g of hydrogen peroxide is 45 g deionized water (H 2O2/CeO2=0.25 M), then filtered and washed from ammonium nitrate. The filter cake is re-suspended in water and alloyed 15 ppm Pd in the form of nitrate. The suspension is spray dried, calcined for 1 hour at 500°and subjected to aging for 4 hours at 1000°C. KE sample at 500°using gravimetric device is equal to 310 μmol O2/g of sample. The upload speed of oxygen equal to 5.2 mg-O2/m2-min Normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 70.

Example 9

Nitrate solution is prepared and precipitated as in example 6. The nitrates of cerium and zirconium added lanthanum nitrate, resulting in the content of solid material in the solution of mixed nitrates equal to 27.3% wt. in the calculation of the oxide. Deposition, drying and calcination performed as in example 6, receiving the final oxide composition with 51% wt. CeO2, 44% wt. ZrO2and 5% wt. La2About3. After aging powder for 4 hours at 1000°With oxygen capacity, based on measurements using TGA, equal 391 μmol O2/g of sample. The upload speed of oxygen equal to 3.4 mg-O2/m2-min Normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 92.

Example 10

46,5 g of an aqueous solution of cerium nitrate (III) (28,5% solid material) is mixed is to 61.8 g of an aqueous solution of zirconium nitrate (20% wt. solid material) to the concentration of a mixed solution of 23.6% by weight. solid materials based on oxides. The solution is poured into 400 ml of a 5 n solution of ammonia at a temperature of 60°and With continuous stirring. The suspension is stirred for 30 min at 60°With, then add 25 g of 30%aqueous hydrogen peroxide solution.

The precipitate was washed with 3 liters of hot deionized water. The filter cake is diluted with water in ratio 1:1 with the formation of the slurry before spray drying, add 15 ppm palladium in the form of nitrate solution. The dried powder is calcined for 1 hour at 500°With formation of the final composition of the mixture of oxides from 48.4% wt. zirconium oxide and 51.6% wt. cerium oxide.

The powder is subjected to aging for 4 hours at 1000°receiving the product with the size of the surface of <1 m2/, Oxygen capacity (KE) is equal to 339 μmol O2/g sample, and the upload speed of the oxygen - 15,0 mg-O2/m2-min Sample was analyzed using the method of x-ray scattering at small angles (SAXS), as described above, and found the intensity of the normalized scattering I(Q) at Q=0,1 Å-1equal to 54.

Example 11

The solution of mixed nitrates receive, connecting and 17.2 g of an aqueous solution of cerium nitrate (III) (29% oxide) and 67 g of an aqueous solution of hydroxynitrile zirconium with respect to Zr:NO3equal to p is blithedale 1:1 (26,1% wt. oxide). To this solution was added 3.5 g of 28.5%lanthanum nitrate and 4,85 g of 31%aqueous yttrium nitrate. The content of solid materials in the mixed solution is 27% wt. based on the oxides. The final oxide composition contains 20% wt. CeO2, 70% wt. ZrO2, 4% wt. La2About3and 6% wt. Y2About3. The solution is added to 300 ml of a 5 n solution of ammonia at 40°C. Precipitated precipitated hydroxide is treated with 51 ml of 3%aqueous hydrogen peroxide solution.

The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25. The filter cake is re-suspended in water and add 15 ppm Pd in the form of nitrate. The resulting mixture was subjected to spray-dried and calcined for 1 hour at 500°C. the Calcined powder is subjected to aging for 4 hours at 1000°With, then measure present in the sample of oxygen at 500°using gravimetric device. KE is equal to 260 μmol O2/g of sample, and normalized scattering intensity I(Q) at Q=0,1 Å-185. The upload speed of the oxygen - 5,8 mg-O2/m2-minutes

Example 12

The solution of mixed nitrates receive, connecting 88.9 g of an aqueous solution of cerium nitrate (III) (28.3% of oxide) and 84,9 g of an aqueous solution of hydroxynitrile zirconium with respect to Zr:NO3approximately 1:1 (26,1% wt. oxide). To this solution we use the t 6.25 g of praseodymium carbonate and 1.5 g of nitric acid. The content of solid materials in the mixed solution is 26.5% wt. based on the oxides. The final oxide composition comprises 50 wt.%. CeO2, 44% wt. ZrO2and 6% wt. Pr6About11. The solution is added to 700 ml of a 5 n solution of ammonia at 40°C. Precipitated precipitated hydroxide is treated with 103 ml of 3%aqueous hydrogen peroxide solution.

The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25. The filter cake is re-suspended in water and add 15 ppm Pd in the form of nitrate. The resulting mixture was subjected to spray-dried and calcined for 1 hour at 500°C. the Calcined powder is subjected to aging for 4 hours at 1000°With, then measure present in the sample of oxygen at 500°using gravimetric device. KE is equal to 396 μmol O2/g of sample, and normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 79. The upload speed of the oxygen - 7,6 mg-O2/m2-minutes

Example 13

The solution of mixed nitrates receive, connecting 88.9 g of an aqueous solution of cerium nitrate (III) (28.3% of oxide) and 84,9 g of an aqueous solution of hydroxynitrile zirconium with respect to Zr:NO3approximately 1:1 (26,1% wt. oxide). To this solution add 5,64 g of yttrium carbonate and 3 g of nitric acid. The content of solid materials in the mixed solution is 26% by weight based on the oxides. The final oxide composition contains 50,6% wt. SEO2, 44.4% of wt. ZrO2and 5% wt. Y2About3. The solution is added to 700 ml of a 5 n solution of ammonia at 40°C. Precipitated precipitated hydroxide is treated with 103 ml of 3%aqueous hydrogen peroxide solution.

The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25. The filter cake is re-suspended in water and add 15 ppm Pd in the form of nitrate. The resulting mixture was subjected to spray-dried and calcined for 1 hour at 500°C. the Calcined powder is subjected to aging for 4 hours at 1000°With, then measure present in the sample of oxygen at 500°using gravimetric device. KE is equal to 344 μmol O2/g of the sample and normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 81. The upload speed of the oxygen - 4,2 mg-O2/m2-minutes

Example 14

The solution of mixed nitrates receive combining is 87.4 g of an aqueous solution of cerium nitrate (III) (29% oxide) and 84,1 g of an aqueous solution of hydroxynitrile zirconium with respect to Zr:NO3approximately 1:1 (26,4% wt. oxide). To this solution was added 2.5 g of gadolinium oxide and 3 g of nitric acid. The content of solid materials in the mixed solution is 27% wt. based on the oxides. The final oxide composition contains 50,6% wt. CeO2, 44.4% of wt. ZrO and 5% wt. Gd2O3. The solution is added to 700 ml of a 5 n solution of ammonia at 40°C. Precipitated precipitated hydroxide is treated with 103 ml of 3%aqueous hydrogen peroxide solution.

The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25. The filter cake is re-suspended in water and add 15 ppm Pd in the form of nitrate. The resulting mixture was subjected to spray-dried and calcined for 1 hour at 500°C. the Calcined powder is subjected to aging for 4 hours at 1000°With, then measure present in the sample of oxygen at 500°using gravimetric device. KE is equal to 384 μmol O2/g of sample, and normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 65. The upload speed of the oxygen - 4,0 mg-O2/m2-minutes

Example 15

The solution of mixed nitrates receive combining is 87.4 g of an aqueous solution of cerium nitrate (III) (29% oxide) and 84,9 g of an aqueous solution of hydroxynitrile zirconium with respect to Zr:NO3approximately 1:1 (26,1% wt. oxide). To this solution was added 4 g of samarium carbonate and 4 g of nitric acid. The content of solid materials in the mixed solution is 27% wt. based on the oxides. The final oxide composition contains 50,6% wt. SEO2, 44.4% of wt. ZrO2and 5% wt. Sm2About3. The solution is added to 700 ml of a 5 n solution of MMA is aka at 40° C. Precipitated precipitated hydroxide is treated with 103 ml of 3%aqueous hydrogen peroxide solution.

The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25. The filter cake is re-suspended in water and add 15 ppm Pd in the form of nitrate. The resulting mixture was subjected to spray-dried and calcined for 1 hour at 500°C. the Calcined powder is subjected to aging for 4 hours at 1000°With, then measure present in the sample of oxygen at 500°using gravimetric device. KE is equal to 385 μmol O2/g of sample, and normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 70. The upload speed of oxygen equal to 3.8 mg-O2/m2-minutes

Example 16

The solution of mixed nitrates receive combining is 87.4 g of an aqueous solution of cerium nitrate (III) (29% oxide) and 84,1 g of an aqueous solution of hydroxynitrile zirconium with respect to Zr:NO3approximately 1:1 (26,4% wt. oxide). To this solution was added to 10.5 g of calcium carbonate and 3 g of nitric acid. The content of solid materials in the mixed solution is 27% wt. based on the oxides. The final oxide composition contains 50,6% wt. CeO2, 44.4% of wt. ZrO2. and 5% wt. The CaO. The solution is added to 700 ml of a 5 n solution of ammonia at 40°C. Precipitated precipitated hydroxide is treated with 103 ml of 3%aqueous solution per the TRC hydrogen.

The molar ratio of hydrogen peroxide to the cerium oxide is equal to 0.25. The filter cake is re-suspended in water and add 15 ppm Pd in the form of nitrate. The resulting mixture was subjected to spray-dried and calcined for 1 hour at 500°C. the Calcined powder is subjected to aging for 4 hours at 1000°With, then measure present in the sample of oxygen at 500°using gravimetric device. KE is equal to 359 μmol O2/g of sample, and normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 65. The upload speed of the oxygen - 8.5 mg-O2/m2-minutes

Example 17

Repeat example 3 except that after the deposition of the suspension at 60°To raise the temperature and heat the suspension in the mother liquor for 2 h at 90°C. the Precipitate is then filtered off, washed and treated as described in example 3. When heated suspension was substantially modified the structure, and the desired domain structure was destroyed by high temperatures. This led to the fall of KE at 500°With up to a value of only 290 μmol O2/g of sample. The material showed a normalized scattering intensity I(Q) at Q=0,1 Å-1equal to 107. The upload speed of oxygen was equal to 4.3 mg-O2/m2-minutes

Comparative example 1

With eshivot 1147 g of water and 136 g of acetic acid and add 236 g of cerium carbonate with the formation of a light solution of cerium acetate. The mixture is stirred for 48 hours to dissolve the carbonate. The acetate cerium add 512 g of zirconium acetate (20% wt. ZrO2) and stirred until the formation of homogeneous solution. The solution is subjected to spray drying at 110°with the formation of white powder mixed acetates. The powder is calcined for 1 hour in a muffle furnace at a temperature of 500°With formation of the final mixed oxide.

Svezhepoymannyh oxide impregnated with 15 ppm Pd from aqueous nitrate solution and calcined for 1 hour at 500°C. the Sample is subjected to aging for 4 hours at 1000°C. as Measured by TGA at 500°KE 290 μmol O2/g of sample. The sample was analysed using SAXS. The normalized scattering intensity I(Q) at Q=0,1 Å-1equal to only 40, as shown in figure 2. The dependence of the normalized scattering intensity I(Q) of Q is presented in figure 1. The magnitude of the surface is 1 m2/, upload Speed of oxygen equal to 0.5 mg-O2/m2-minutes of the Final oxide composition comprises 60 wt.%. SEO2, 38% wt. ZrO2and 2% wt. La2O3.

Comparative example 2

The powder of mixed oxides prepared using the procedure of comparative example 1 except that svezhepoymannyh sample impregnated with a 1000 ppm of Ni nitrate solution. The powder after e is wow calcined for 1 hour at 500° C. the Sample is subjected to aging for 4 hours at 1000°C. as Measured by TGA at 500°WITH KE $ 218 μmol O2/g sample, and normalized scattering intensity I(Q) at Q=0,1 Å-146. The upload speed of oxygen equal to 0.2 mg-O2/m2-minutes

Comparative example 3

An aqueous solution of cerium nitrate (III) is prepared by dissolution of 58.6 g of cerium carbonate (III) (49.5% of oxide) in 135 g of water and 50.4 g of concentrated nitric acid. To the solution add 110,5 g zirconyl-nitrate (20% wt. oxide). The concentration of solid materials in the final solution of mixed nitrates equal to 15.7% of wt. To nitrate solution was added 50 g of 30%aqueous hydrogen peroxide. 350 g of deionized water at 70°With peroxidized nitrate solution is subjected to co-deposition in the vessel with 300 ml of 5 n ammonia, while maintaining a temperature of 70°and a pH of 8.6. After adding the total amount of solution residue is subjected to aging for 0.5 hour at 70°C.

The precipitate is filtered off, washed with 3 l of water at 70°C. the Washed filter cake is re-suspended in water and spray dried. The dried powder is impregnated with 15 ppm Pd in the form of nitrate solution and calcined for 1 hour at 500°With formation of the product with the size of the surface of >100 m2/g After aging for 4 hours at 1000°Velich is on the surface is equal to 17 m 2/, KE, measured by TGA isothermal at 500°is only 274 μmol O2/g of sample. The sample was analyzed using SAXS method. The normalized scattering intensity I(Q) at Q=0,1 Å-1measured using SAXS, as shown in figure 2, equal to 152. The upload speed of oxygen equal to 2.4 mg-O2/m2-minutes

Comparative example 4

The filter cake of comparative example 4 impregnate before calcination 100 ppm Pd. KE, measured by TGA isothermal at 500°is only 275 μmol O2/g of sample. The normalized scattering intensity I(Q) at Q=0,1 Å-1measured using SAXS equal to 120. The upload speed of oxygen equal to 4.0 mg-O2/m2-minutes

Although the present invention is described in various preferred embodiments, an experienced specialist it is clear that, without leaving the scope of the invention, it is possible to make various modifications, substitutions, omissions and changes.

1. A mixed oxide of cerium oxide and zirconium oxide having a multiphase cubic form of crystallization and oxygen capacity of at least 260 µmol O2/g of sample and upload speed of oxygen greater than 1.0 mg-O2/m2-min, measured after aging for 4 hours at 1000°C.

2. Smiling is hydrated oxide according to claim 1, in which the oxygen storage capacity after aging for 4 hours at 1000°With more than 315 μmol O2/g of sample.

3. Mixed oxide according to claim 2, in which the oxygen storage capacity after aging for 4 hours at 1000°With more than 330 µmol O2/g of sample.

4. Mixed oxide according to claim 3, which has a download speed of oxygen greater than 2.0 mg-O2/m2-min and measured after aging for 4 hours at 1000°C.

5. Mixed oxide according to claim 4, which has a download speed of oxygen greater than 5.0 mg-O2/m2-min and measured after aging for 4 hours at 1000°C.

6. Mixed oxide according to claim 1, which is based on the determination using the method of scattering of x-rays at small angles (SAXS) is a normalized scattering intensity I(Q) in the range from about 47 to about 119 when the scattering vector Q 0.10 Å-1.

7. Mixed oxide according to claim 6, which on the basis of determination by the method of the scattering of x-rays at small angles (SAXS) is a normalized scattering intensity I(Q) in the range from 50 to 110 when the scattering vector Q 0.10 Å-1.

8. Mixed oxide according to claim 6, which on the basis of determination by the method of the scattering of x-rays at small angles (SAXS) is a normalized scattering intensity I(Q) in the range from 54 to 85 when the scattering vector Q, equally the m 0,10 Å -1.

9. Mixed oxide according to claim 1, which is based on the determination using the method of scattering of x-rays at small angles (SAXS) is a normalized scattering intensity I(Q) ranging from 47 to 119 when the scattering vector Q 0.10 Å-1.

10. Mixed oxide according to claim 9, which on the basis of determination by the method of the scattering of x-rays at small angles (SAXS) is a normalized scattering intensity I(Q) in the range from 50 to 100 when the scattering vector Q 0.10 Å-1.

11. The mixed oxide of claim 10, which on the basis of determination by the method of the scattering of x-rays at small angles (SAXS) is a normalized scattering intensity I(Q) in the range from 54 to 85 when the scattering vector Q 0.10 Å-1.

12. Mixed oxide according to claim 1, which includes polycrystalline particles of cerium oxide and zirconium oxide.

13. Mixed oxide according to item 12, wherein the particles have an average size in the range from 0.1 to 50 μm.

14. Mixed oxide according to item 13, wherein the particles have an average size in the range from 0.5 to 20 μm

15. Mixed oxide according to item 12, wherein the particles contain crystallites having an average size that is defined after calcination for 4 hours at 900°using x-ray diffraction, in the range from 40 to 200 Å.

16. Mixed oxide according to item 15, the which the crystallites have an average size certain, after annealing for 4 h at 900°using x-ray diffraction in the range from 50 to 120 Å.

17. Mixed oxide according to item 15, in which the crystallites include many adjacent one to the other domains within the same crystallite vary considerably atomic ratio of cerium and zirconium.

18. Mixed oxide by 17, in which the domains have an average size ranging from 10 to 50 Å.

19. Mixed oxide on p, in which the domains have an average size ranging from 10 to 30 Å.

20. Mixed oxide according to item 12, in which particles of mixed oxide have a size specific surface after calcination for 2 h at 500°equal to at least 30 m2/year

21. Mixed oxide according to claim 20, in which particles of mixed oxide have a size specific surface after calcination for 2 h at 500°equal to at least 40 m2/year

22. Mixed oxide according to item 21, in which particles of mixed oxide have a size specific surface after calcination for 2 h at 500°equal to at least 50 m2/year

23. Mixed oxide according to item 12, in which particles of mixed oxide have a size specific surface after calcination for 4 hours at 1000°With not more than 10 m2/year

24. Mixed oxide according to item 23, in which particles of mixed oxide which have a specific surface area after calcination for 4 hours at 1000° With no more than 5 m2/year

25. Mixed oxide according to paragraph 24, in which particles of mixed oxide have a size specific surface after calcination for 4 hours at 1000°With not more than 3 m2/year

26. Mixed oxide according to claim 1, which contains from about 80 to 20 wt.% CeO2and from about 20 to 80 wt.% ZrO2.

27. Mixed oxide on p, which contains from 40 to 60 wt.% CeO2and from 60 to 40 wt.% ZrO2.

28. Mixed oxide according to item 27, which contains 50 wt.% CeO2and 50 wt.% ZrO2.

29. Mixed oxide on p, which further comprises 10 wt.% metal oxide other than cerium oxide.

30. Mixed oxide according to clause 29, in which the metal oxide other than cerium oxide, selected from the group consisting of oxide of rare earth metal other than cerium oxide, calcium oxide and mixtures thereof.

31. Mixed oxide according to item 30, in which the oxide of rare earth metal oxide is selected from the group consisting of lanthanum, praseodymium, neodymium, samarium, gadolinium and yttrium.

32. The method of obtaining polycrystalline particles of mixed oxide of cerium and zirconium, as claimed in any one of claims 1 to 31, including

i) obtaining a solution of a mixed salt comprising at least one salt of cerium and at least one salt of zirconium in a concentration sufficient to generate polycrystallites is their particles corresponding dry product-based mixed oxide, moreover, these particles are cerium oxide component and the zirconium oxide component, in which these components reside inside subcritically structure of particles in such a way that each crystallite in the particle consists of many adjacent one to the other domains, in which the atomic relations of Ce:Zr, which have adjacent one to the other domains are characterized by the degree of heterogeneity with respect to one another, determined by the method of x-ray scattering at small angles and expressed normalized scattering intensity I(Q) in the range from about 47 to about 119 when the scattering vector Q 0.10 Å-1and named the mixed oxide is characterized by the fact that they get particles of cerium oxide and zirconium with oxygen capacity equal to at least 260 µmol O2/g of sample and upload speed of oxygen greater than 1 mg-O2/m2-min, measured after aging for 4 hours at 1000°C;

ii) treatment of a solution of mixed salts obtained in accordance with stage (i), base with sediment;

iii) processing the precipitate obtained in accordance with stage (ii)as oxidizing agent in a quantity sufficient to oxidize CE+3to CE+4;

iv) washing and drying of the residue obtained in sootvetstviis stage (iii); and

(v) calcining the dried precipitate obtained in accordance with stage (iv), resulting in a gain of polycrystalline particles of cerium oxide and zirconium.

33. The method according to p, in which the residue is treated with dilute aqueous hydrogen peroxide to oxidize CE+3to CE+4.

34. The method according to p, in which the residue is treated with dilute aqueous hydrogen peroxide in a quantity sufficient to provide a molar relationship of hydrogen peroxide to Behold from about 0.25 to about 1.

35. The method according to clause 34, in which the residue is treated with dilute aqueous hydrogen peroxide in a quantity sufficient to provide a molar relationship of hydrogen peroxide to Behold from about 0.5 to about 1.

36. The method according to p, in which the concentration of solid material in the solution of the mixed salts is at least 23 wt.% in the calculation of the oxide.

37. The method according to p, in which the concentration of solid material in the solution of the mixed salts is at least 25 wt.% in the calculation of the oxide.

38. The method according to p, in which the concentration of solid material in the solution of the mixed salts is in the range from about 24 to about 39 wt.% in the calculation of the oxide.

39. The method according to § 38, in which the concentration of solid material in the solution of the mixed salts is in the range from about 25 to about 29 wt.% in the calculations of the e in the oxide.

40. The method according to p, in which the pH value at stage (ii) is from about 8 to 11.

41. The method according to p, in which the temperature at stages ii) and (iii) does not exceed about 80°C.

42. The method according to paragraph 41, in which the temperature at stages ii) and (iii) does not exceed about 70°C.

43. The method according to p, in which the dried precipitate is calcined at a time to about 6 hours at a temperature of from approximately 500 to approximately 600°C.

44. The method according to p, in which, after deposition in stage (ii) add additional alloying component.

45. The method according to item 44, in which the alloying component is added before or after calcination.

46. The method according to item 45, in which the alloying component is a transition metal of group VIII.

47. The method according to item 46, in which the alloying component is a transition metal selected from the group comprising Nickel, palladium, platinum and mixtures thereof.

48. The method according to p, which precipitate on stage iv) is dried by suspension of sediment in the water, followed by spray drying aqueous suspension.

49. The method according to p, in which the solution of the mixed salts is prepared by mixing a cerium salt with a solution of zirconium salt with a molar ratio of cation to anion is 1:1 to 1:2.

50. The method according to p, in which the solution of the mixed salts is prepared by dissolving carbonate of cerium zirconium salt solution (mol the tion ratio of 1:2 and adding the minimum amount of acid, sufficient to carbonate dissolution.

51. Mixed oxide obtained by the method according to p.

52. The substrate with the coating containing mixed oxide according to claim 1, deposited on the substrate.

53. The substrate with the coating according to claim 1, containing a mixed oxide according to claim 1, deposited on the substrate.

54. The substrate coated according to paragraph 52, containing a mixed oxide according to claim 6, deposited on the substrate.

55. The substrate coated according to paragraph 52, containing a mixed oxide according to claim 9, deposited on the substrate.

56. The substrate is coated on p-55, which is a catalyst or catalyst carrier for purification of exhaust gases.

57. The substrate with the coating according to item 53, which contains the catalytic noble metal deposited on the mixed oxide.

58. The substrate with the coating according to item 54, which contains the catalytic noble metal deposited on the mixed oxide.

59. The substrate coated according to § 55, which contains the catalytic noble metal deposited on the mixed oxide.

60. The substrate is coated on p-59, which is a catalyst for purification of exhaust gases.

61. Mixed oxide having a multi-phase cubic form of crystallization, comprising polycrystalline particles with a component of cerium oxide and a component of zirconium oxide, in which these components reside inside subcritically is tructure particles thus each crystallite in the particle consists of many adjacent one to the other domains, in which the atomic relations of Ce:Zr, which have adjacent one to the other domains are characterized by the degree of heterogeneity with respect to one another, determined by the method of x-ray scattering at small angles and expressed normalized scattering intensity I(Q) in the range from about 47 to about 119 when the scattering vector Q 0.10 Å-1.

62. Mixed oxide on p, which is characterized by the upload speed of oxygen above 1.0 mg-O2/m2-minutes

63. Mixed oxide on p, which is characterized by an oxygen storage capacity after aging for 4 hours at 1000°equal to at least 260 µmol O2/g of sample.

64. Mixed oxide according to item 62, which is characterized by an oxygen storage capacity after aging for 4 hours at 1000°equal to at least 330 µmol O2/g of sample.

65. Mixed oxide on p, whose normalized scattering intensity I(Q) is in the range from 50 to 100 when the scattering vector Q 0.10 Å-1.

66. Mixed oxide on p, whose normalized scattering intensity I(Q) is in the range from 54 to 85 when the scattering vector Q 0.10 Å-1.

67. Mixed oxide on p, whose schedule C the dependence of the logarithm of the normalized intensity of the scattering LnI(Q) from the logarithm of the scattering vector ln(Q) when -2,5< ln(Q)<-1 is a straight line segment and the angle of inclination of the straight part equal to-4.0±0,4.

68. Mixed oxide, which is based on the determination using the method of scattering of x-rays at small angles (SAXS) is a normalized scattering intensity I(Q) ranging from 47 to 119 when the scattering vector Q 0.10 Å-1and whose graph of the logarithm of the normalized intensity of the scattering LnI(Q) from the logarithm of the scattering vector ln(Q) when -2,5<ln(Q)<-1 is a straight line segment and the angle of inclination of the straight part equal to-4.0±0,4.



 

Same patents:

FIELD: sorbents.

SUBSTANCE: invention provides zirconium oxide-based mesoporous material with following composition: SO42-/ZrO2-EOx, where E represents group III or IV element, x = 1.5 or 2, content of sulfate ions 0.1-10 wt %, and molar ratio ZrO2/EOx = 1:(0.4-1.0), said material having specific surface 300-800 m2/g with total pore volume 0.3 to 0.8 cm3/g. Method involves preparation of composition consisted of hydrated zirconium sulfate, sulfate ions, and water via precipitation of hydrated oxide phase from soluble zirconium or zirconyl salts followed by hydrothermal reprecipitation in presence of cationic surfactants to form mesoporous structure, which is then stabilized by treatment with group III or IV element compounds taken is additive proportions to mesoporous crystalline structure.

EFFECT: achieved preparation of material with controlled acid-base properties, high specific surface, and elevated heat resistance.

7 cl, 2 dwg, 6 tbl, 13 ex

FIELD: protective coatings.

SUBSTANCE: invention relates to heat-resistant coatings made of ceramic materials and to metallic articles having such type coatings, said articles being effectively applicable in gas-turbine engines. Coatings contain at least one oxide and another oxide selected from zirconium dioxide, cerium oxide, and hafnium oxide, said at least one oxide having general formula A2O3 wherein A is selected from group consisting of La, Pr, Nd, Sm, Eu, Tb, In, Sc, Y, Dy. Ho, Er, Tm, Yb, Lu, and mixtures thereof. Metallic articles are therefore constituted by metal substrate and above defined coating.

EFFECT: reduced heat conductance providing high efficiency use in gas-turbine engines.

52 cl, 6 ex

The invention relates to Sol-gel technologies for Staropromyslovsky of ion exchangers and sorbents on the basis of hydroxide and zirconium oxide, as well as catalysts and powders for plasma spraying and high temperature ceramics based on zirconium dioxide

The invention relates to the field of materials science, in particular to methods for initial substances for composite materials and structural ceramics
The invention relates to the purification of baddeleyite concentrates, in particular the production of fine powders of zirconium oxide

The invention relates to reflective coatings and can be used in aircraft and space technology
The invention relates to the purification of baddeleyite concentrate of impurities, including impurities of radioactive elements

The invention relates to growing synthetic crystals and is industrially applicable in the manufacture of jewelry, and high-strength optical parts (small Windows, lenses, prisms, etc.,)

FIELD: chemistry of rare-earth elements, chemical technology.

SUBSTANCE: invention relates to the improved methods (variants) for preparing salts formed by neodymium and organic acids that are used as components on preparing metal-chelating catalysts. Method for preparing neodymium organic salts from neodymium oxide and carboxylic acid involves conversion of neodymium oxide to a water-soluble salt by heating at temperature 50-150°C with inorganic ammonium salt aqueous solution with simultaneous distillation of water and ammonia. Then carboxylic acid is converted to water-soluble ammonium salt by mixing with distilled ammonia and water. In mixing prepared aqueous solutions of inorganic neodymium salt with organic ammonium salt the neodymium organic salt and inorganic ammonium salt aqueous solution are prepared. After isolation of the end neodymium organic salt an aqueous solution of ammonium inorganic salt is recirculated to the process. Method for preparing neodymium organic salts from neodymium oxide and carboxylic acids (variant) involves conversion of neodymium oxide to water-soluble inorganic salt by heating at temperature 50-150°C with inorganic ammonium salt aqueous solution and with simultaneous distillation of water and ammonia. Then carboxylic acid and hydrocarbon solvent are added to neodymium inorganic salt aqueous solution followed by addition of distilled ammonia at intensive stirring. After ceasing the stirring the reaction mixture if separated for aqueous and organic layers. Aqueous layer representing inorganic ammonium salt solution is recirculated to the process and the end product is isolated from an organic layer representing neodymium organic salt solution in hydrocarbon solvent, or solution of the definite concentration is prepared. Proposed methods (variants) provides excluding consumption of additional reagents and creates conditions for wasteless production of neodymium organic salts from neodymium oxide and organic acids.

EFFECT: improved preparing method.

8 cl, 4 ex

FIELD: chemical technology, production of rear earth element compounds, in particular production of polishing material for optical glass treatment.

SUBSTANCE: claimed method includes fluorination of rear earth element carbonates and calcinations of fluorinated carbonates. Rear earth element carbonates are prepared by deposition from rear earth element chloride solution with sodium carbonate solution on previously prepared crystallizing grains such as seeding agent obtained by deposition from rear earth element chloride solution having concentration of 60-70 g/l with sodium carbonate solution having concentration of 60-70 g/l at 20-25°C, solution pH 4.6-4.9 for 1-1.5 hour. Deposited carbonates are washed. Method of present invention makes it possible to obtain fluorine-containing polishing material with particle size of 0.8-1.0 mum.

EFFECT: improved material useful in polishing of precise optic materials.

2 cl, 1 tbl, 1 ex

FIELD: radiochemistry, medicine.

SUBSTANCE: invention relates to method for isolation and purification of multycurie amounts of Y90 having satisfactory chemical and radiochemical purity without application of extraction chromatography columns selective to Sr90 and with minimal losses of starting Sr90 and exhaust flow. Claimed method includes utilization of starting Sr90 solution wherein at least 80-90 % strontium represents stable Sr, dissolution of nitrate salt, containing in starting Sr90 solution to obtain strontium nitrate solution; acidifying of strontium nitrate solution containing Y90 with concentrated nitric acid; evaporation of strontium nitrate solution; followed by filtration or centrifugation of strontium nitrate solution to separate Sr90 nitrate crystal salt from solution and to obtain yttrium-enriched supernatant; evaporation of said yttrium-enriched supernatant to dry state; dissolution of nitric acid-free yttrium-enriched supernatant in strong acid; solution passing through selective to yttrium extraction chromatography column in such a manner that essentially total amount of abovementioned yttrium isotope is retained in column, and other metal and admixture traces pass through column and recycled in starting strontium solution; washing of selective to yttrium extraction chromatography column with strong acid to remove total residual Sr90 which is recycled in abovementioned starting Sr90 solution; and isolation of yttrium isotope from selective to yttrium extraction chromatography column with strong acid. Method of present invention provides Sr90 yield of more than 99.9 % and increased Y purity after each cycle. Method is useful in medicine.

EFFECT: method for isolation and purification of yttrium isotope with increased yield and purity.

11 cl, 2 tbl, 2 dwg

FIELD: protective coatings.

SUBSTANCE: invention relates to heat-resistant coatings made of ceramic materials and to metallic articles having such type coatings, said articles being effectively applicable in gas-turbine engines. Coatings contain at least one oxide and another oxide selected from zirconium dioxide, cerium oxide, and hafnium oxide, said at least one oxide having general formula A2O3 wherein A is selected from group consisting of La, Pr, Nd, Sm, Eu, Tb, In, Sc, Y, Dy. Ho, Er, Tm, Yb, Lu, and mixtures thereof. Metallic articles are therefore constituted by metal substrate and above defined coating.

EFFECT: reduced heat conductance providing high efficiency use in gas-turbine engines.

52 cl, 6 ex

FIELD: inorganic compounds technologies.

SUBSTANCE: invention relates to processing of phosphogypsum, large-scale side product of sulfuric acid-assisted phosphoric acid production process, containing valuable chemicals such as calcium and rare-earth elements. Method is characterized by that carbonization of phosphogypsum is first performed with 2.0-2.5 M sodium carbonate solution at 60-80°C for 30-45 min, at liquid-to-solids ratio 2.0-2.5 to form solid precipitate (insoluble precipitate 1: industrial-grade rare-earth element-contaminated calcium carbonate) and liquid phase, which is evaporated to produce sodium chloride as commercial product. Insoluble precipitate 1 is further calcined at 900-950°C, treated with ammonium chloride and resulting calcium chloride solution is separated from rare-earth element-containing insoluble precipitate (insoluble precipitate 2). The former is carbonized to produce commercial calcium carbonate and the latter is treated with 5-6% hydrochloric acid mixed with ascorbic acid at 80-90°C for 30-60 min, ascorbic acid-to-rare-earth elements weight ratio being (0.4-0.5):1. Thus formed solution containing rare-earth elements is separated from solid 30-32% strontium concentrate, recovered as commercial product, and then neutralized with ammonia to pH 9.0-9.5 to precipitate rare-earth elements. Precipitate is treated with sodium sulfate solution with pH between -0.3 and -0.5 at 80-90°C for 60-90 min to remove phosphates and sesquialteral oxides (R2O3) and to produce precipitate containing calcium sulfate and rare-earth elements, which is dried to give commercial product containing mixed calcium and rare-earth element sulfates. Insoluble precipitate 2 containing rare-earth elements is subjected to treatment with aqueous hydrochloric acid in presence of ascorbic acid, solid phase, which is strontium concentrate, is recovered as commercial product and liquid phase is treated with ammonia to pH 9.0-9.5. Resulting precipitate containing rare-earth elements is separated from liquid phase and treated with sodium sulfate solution, after which calcium sulfate and rare-earth elements are separated by known methods.

EFFECT: maximized recovery of valuable components as desired commercial products.

5 cl, 2 dwg, 4 tbl

FIELD: industrial inorganic synthesis.

SUBSTANCE: process involves dissolving scandium-containing concentrate in mineral acid, removing impurities from scandium solution, separating precipitate from the solution. Precipitate obtained is treated with alkali reagent, and pulp is filtered. Separated scandium oxyhydrate precipitate is treated with formic acid, resulting slurry is filtered, scandium formate is separated from mother liquor, washed, dried, and calcined.

EFFECT: simplified process and reduced loss of scandium in concentrate processing stage.

5 cl, 2 ex

FIELD: non-iron metallurgy, in particular scandium oxide recovery from industrial waste.

SUBSTANCE: method for preparation of scandium oxide from red mud being waste of alumina production includes: multiple subsequent leaching of red mud with mixture of sodium carbonate and hydrocarbonate solutions; washing and precipitate separation; addition into obtained solution zinc oxide, dissolved in sodium hydroxide; solution holding at elevated temperature under agitation; precipitate separation and treatment with sodium hydroxide solution at boiling temperature; separation, washing, and drying of obtained product followed by scandium oxide recovery using known methods. Leaching is carried out by passing through mixture of sodium carbonate and hydrocarbonate solutions gas-air mixture containing 10-17 vol.% of carbon dioxide, and repeated up to scandium oxide concentration not less than 50 g/m3; solid sodium hydroxide is introduced into solution to adjust concentration up to 2-3.5 g/m3 as calculated to Na2O (caustic); and mixture is hold at >=800C followed by flocculating agent addition, holding, and separation of precipitate being a titanium concentrate. Obtained mixture is electrolyzed with solid electrode, cathode current density of 2-4 A/dm3, at 50-750C for 1-2 h to purify from impurities. Zinc oxide solution in sodium hydroxide is added into purified after electrolysis solution up to ratio ZnO/Sc2O3 = (10-25):1, and flocculating agent is introduced. Solution is hold at 100-1020C for 4-8 h. Separated precipitate is treated with 5-12 % sodium hydroxide solution, flocculating agent is introduced again in amount of 2-3 g/m3, mixture is hold, and precipitate is separated. Method of present invention is useful in bauxite reprocessing to obtain alumina.

EFFECT: improved recovery ratio of finished product into concentrate; decreased impurity concentration in concentrate, reduced sodium hydrocarbonate consumption, as well as reduced process time due to decreased time of fine-dispersed precipitate.

2 cl, 2 ex

FIELD: nonferrous metallurgy.

SUBSTANCE: invention relates to hydrometallurgy of rare-earth elements, in particular to technology of preparing of rare-earth element carbonates with controlled particular shape used in manufacture of polishing materials and catalysts. Suspension of rare-earth element carbonates prepared by mixing rare-earth element carbonate solution with carbonic acid solution is stirred at 20 to 75оС at suspension motion velocity between 0.5 and 20 m/s, whereupon rare-earth element carbonates are precipitate in plate form at stirring for a period of time satisfying relationship 1.5*T0.5 ≤ τ ≤ 30. Precipitation of dendritic carbonates is accomplished at stirring for a period of time satisfying relationship 106*T-2.5 ≤ τ ≤ 600, where τ are numeric values of stirring time, min, and T are numeric values of reaction medium temperature, оС.

EFFECT: extended temperature range for precipitation of plate- and dendritic-form rare-earth element carbonates and improved granulometric uniformity of product.

2 dwg, 2 ex

FIELD: inorganic synthesis. lanthanoid

SUBSTANCE: method comprises interaction of lanthanoid with iodine in vacuum or inert gas atmosphere on heating. Reaction is initiated by heating reactor containing lanthanoid or lanthanoid/iodine mixture and carried out stepwise. Iodine portion or iodine/lanthanoid mixture portion is first added to hot lanthanoid or lanthanoid/iodine mixture. Once reaction is terminated, next portion of iodine or iodine/lanthanoid mixture is added. Resulting mixture is additionally heated at stirring in vacuum, preferably at 600-800оС. Method is also appropriate to obtain samarium, europium, dysprosium, ytterbium, neodymium, and thulium diiodides wherein content of bivalent lanthanoid is at the level of 94-98%.

EFFECT: enabled preparation of title compounds in unlimited quantities.

3 cl, 3 ex

FIELD: ear-earth element compounds, in particular cerium dioxide.

SUBSTANCE: invention relates to simplified method for production of cerium dioxide having high specific surface useful for catalyst preparation. Method includes blending of (mass %) cerium carbonate 44-58; ammonia acetate 25-34; and water 14-25. Obtained mixture is dried in air and baked at 7000C.

EFFECT: simplified method for production of cerium dioxide.

2 cl, 1 tbl, 1 ex

FIELD: catalyst preparation methods.

SUBSTANCE: invention provides Fischer-Tropsch catalyst, which consists essentially of cobalt oxide deposited on inert carrier essentially composed of alumina, said cobalt oxide being consisted essentially of crystals with average particle size between 20 and 80 Å. Catalyst preparation procedure comprises following stages: (i) preparing alumina-supported intermediate compound having general formula I: [Co2+1-xAl+3x(OH)2]x+[An-x/n]·mH2O (I), wherein x ranges from 0.2 to 0.4, preferably from 0.25 to 0.35; A represents anion; x/n number of anions required to neutralize positive charge; and m ranges from 0 to 6 and preferably is equal to 4; (ii) calcining intermediate compound I to form crystalline cobalt oxide. Invention also described a Fischer-Tropsch process for production of paraffin hydrocarbons in presence of above-defined catalyst.

EFFECT: optimized catalyst composition.

16 cl, 12 tbl, 2 ex

Up!