Exhaust gas treatment catalyst characterized by silica-based support

FIELD: exhaust gas afterburning means.

SUBSTANCE: invention relates to catalytic neutralizer for treating internal combustion engine exhausted gases. Proposed catalyst is composed of catalytically active coating on inert ceramic or metallic honeycomb structure, wherein coating contains at least one platinum group metal selected from series including platinum, palladium, rhodium, and iridium on fine-grain supporting oxide material, said supporting oxide material representing essentially nonporous silica-based material including aggregates of essentially spherical primary particles 7 to 60 nm in diameter, while pH of 4% water dispersion of indicated material is below 6.

EFFECT: increased catalyst activity and imparted sufficient resistance to aggressive sulfur-containing components.

27 cl, 2 dwg, 7 tbl, 6 ex

 

The present invention relates to a catalyst (catalytic Converter for cleaning exhaust gases of an internal combustion engine, comprising a catalytically active coating on an inert ceramic or metal honeycomb structure, and the coating includes at least one of platinum group metals, i.e. platinum, palladium, rhodium or iridium, on fine-grained oxide material media. This catalyst is particularly suitable for the oxidative purification of exhaust gases of diesel engines, since it exhibits good resistance to poisoning serosoderzhashchimi components of diesel fuel.

Diesel engines operate on the so-called poor fuel-air mixtures, which means that the air-fuel mixture supplied to the engine, contains more oxygen than required for complete combustion of the fuel. In addition to unburned hydrocarbons (HC) and carbon monoxide (CO), the exhaust gases of diesel engines also contain oxides of nitrogen (NOx) and soot particles. Other toxic components included in the exhaust gas is sulfur dioxide, which is formed from sulfur contained in diesel fuel.

For cleaning exhaust gases of diesel engines often use the so-called diesel oxidation neutralizate is s, which convert hydrocarbons and carbon monoxide in the exhaust gases into harmless components. Moreover, these catalysts reduce the mass of particles due to oxidation of adsorbed on particles of organic compounds.

Typical catalysts of this type include a coating on one or more oxide media (for example, aluminum oxide, silicon dioxide, titanium dioxide, cerium oxide, and their mixtures) and one or more zeolites, and platinum as a catalytically active component on a ceramic or metal honeycomb structure. Used oxide carriers, or media materials have a large surface area, i.e. their specific surface area (specific surface area by BET, determined in accordance with German industrial standard DIN 66131) is more than 10 m2/g, preferably greater than 50 m2/g Specific surface area should remain stable up to temperatures of exhaust gases of approximately 800°C. to achieve a high degree of catalytic activity on oxide carriers very finely distributed platinum.

The main part of the carbon is released during stage startup from a cold condition, as during this stage, the catalyst has not yet reached its operating temperature is. To reduce hydrocarbon emissions during the stage of cold starts in the catalysts of type zeolites. Zeolites are a special aluminosilicates with a specific porous structure. The pores have dimensions of the same order as the size of small organic molecules. At low temperatures, the zeolites accumulate hydrocarbons, while at higher temperatures, when the active catalyst, the hydrocarbons of the newly released (desorbers) and then subjected to metamorphosis on the platinum fine crystals of the catalyst.

Such a catalyst is described, for example, in US No. 5157007. The catalyst on an inert cellular carrier includes a catalytically active coating, which as oxide materials carriers for catalytically active platinum group metals include aluminum oxide, titanium oxide, silicon dioxide, zeolites or mixtures thereof. As of silicon dioxide using the so-called precipitated silicon dioxide. Precipitated silica is characterized by a large specific surface area. The value of pH in 5%aqueous dispersion exceeds 6 (Schriftenreihe Pigmente Nummer 31: "Synthetische Kieselsäuren als Flieβhilfsmittel und als Trägersubstanz" [Technical Bulletin Pigments No. 31: "Synthetic silica as free flow agent and support substance"]; branded brochure from the company Degussa AG; 6th edition, November, 1995). As the oxide Titus is and use, among other things, the pyrogenic titanium oxide with a specific surface area of 51 m2/year

In US no 5928981 described catalyst for cleaning exhaust gases of diesel engines, and the catalyst includes a mixture of several zeolites. As the material of the carrier for the catalytically active platinum group metals such catalyst additionally contains at least one material selected from the group comprising aluminum silicate, aluminum oxide and titanium oxide. As a suitable titanium oxide mentioned the pyrogenic titanium oxide obtained by hydrolysis in the flame and having a specific surface area of 50 m2/g, which consists of 70 wt.% anatase and 30 wt.% rutile.

In the last few years significant progress has been made in creating an efficient diesel engines. Thanks to their high efficiency of modern diesel engines have a very low exhaust gas temperature, which during driving in an urban environment may be less than 150°C. These temperatures cause completely new demands on the reliability of diesel catalysts. Due to the low temperatures of the exhaust gas cleaning exhaust gases of such diesel engines leads to adsorption increased amounts of hydrocarbons,which clog the pores of the catalyst. This entails a reduction of catalytic activity. The catalyst may even completely fail, causing failure of the engine due to the high back pressure of the exhaust gas.

Also crucial alternating modes of operation consisting in longer periods of driving at low load, followed by a sharp acceleration to maximum load. These alternate modes of operation can cause thermal damage to the catalyst, when long periods of driving at low load lead to adsorption on the catalyst of large quantities of hydrocarbons that when the mode is changed to the maximum load quickly burn. The released reaction heat may cause the temperature rise on the surface of the catalyst up to 1000°and to cause thermal damage to the catalyst.

Another problem that faced the catalysts for purification of exhaust gases of diesel engines, due to the sulfur content in diesel fuel, which stands out with the engine in the form of sulfur dioxide and is adsorbed by the catalyst in the form of sulphates, which damage the catalyst. In order to reduce the damage caused by serosoderzhashchimi components, known application of acid oxide carriers for catalytically active precious m is the metal, only in a small degree adsorb sulfur.

Presents figures 1 and 2.

Figure 1 shows a photograph of the structure of platinum on aluminum silicate (table 1 material carrier No. 3), performed using a transmission electron microscope.

Figure 2 shows a photograph of the structure of platinum on the pyrogenic silicon dioxide (table 1 material carrier No. 6), performed using a transmission electron microscope.

There is a need in diesel catalytic converters that exhibit increased resistance to aging, and decreased susceptibility to poisoning serosoderzhashchimi components in comparison with the known catalysts.

The present invention proposes a catalyst for cleaning exhaust gases of an internal combustion engine, which includes a catalytically active coating on an inert ceramic or metal honeycomb structure, and the coating includes at least one platinum group metal selected from a range that includes platinum, palladium, rhodium and iridium, on fine-grained oxide material media. This oxide material of the carrier is a material with low porosity based on silicon dioxide and includes aggregates of essentially spherical primary particles, the average diameter of which is located is between 7 and 60 nm.

In accordance with the present invention as a material carrier, which includes aggregates of essentially spherical primary particles, use special silicon dioxide. In the description of the present invention, the term "essentially spherical" is used to denote the form of particles, which is characterized by a smooth surface and a geometric shape which approaches the shape of a ball. However, this definition also covers primary particles teardrop shape or primary particles of a complex configuration with a smooth surface that has a shape similar to a spherical. One characteristic of this material lies in the fact that its specific surface area is due largely to the geometric surface (outer surface) of the primary particles, i.e. this material shows almost complete absence of pores. Essentially it is non-porous.

Material that is intended for use in accordance with the present invention, can be easily distinguished from conventional, porous silica materials using electron microscope. Studies using the electron microscope clearly demonstrate porous primary particles and allow us to determine the average diameter of these particles. Such studies can be conducted even with samples of finished rolled the optical coating, they provide the opportunity to identify the material.

Non-porous silicon dioxide can be prepared, for example, processing of silicon tetrachloride so-called hydrolysis in the flame (see, for example, "Schriftenreihe Pigmente" by the company Degussa AG, number 11, edition 5, August 1991: "Grundlagen von Aerosil®" [Technical Bulletin Pigments No. 11: The basics of Aerosil®]). To this end, the silicon tetrachloride is transferred into the gas phase and subsequently perform quantitative reaction with water in the flame detonating gas, thus obtaining the target silicon dioxide. However, such materials can also be obtained in an arc and plasma. In subsequent silica obtained by hydrolysis in the flame, also referred to as pyrogenic silicon dioxide.

Thanks to their solidification from the melt obtained primary particles are essentially spherical. They stick together with other primary particles and form what are called aggregates, which usually cannot be mechanically separated again at the individual primary particles.

The size of the primary particles can be adjusted in the range of from about 7 to 60 nm modification of process parameters of hydrolysis in the flame. In a preferred embodiment, the catalyst in accordance with the present invention using such material, the average size of the primary particles exceeds 15 is m, and the specific surface area of approximately 150 m2/, In a particularly preferred embodiment, the average primary particle size of the material of the carrier is within a 20 and 50 nm and a specific surface area in the range of 90 and 40 m2/year

Pyrogenic silica is essentially non-porous material and in the preferred embodiment, has a pore volume less than 0.2 ml/g and pore diameters less than 30 nm. The maximum diameter of its pores is usually greater than 20 nm. Such material in the preferred embodiment, showing an acidic reaction, i.e. the pH value of the dispersion concentration of 4 wt.% is less than 6, more preferably less than 5,5.

To improve the heat resistance of the material of the carrier can be legitamate one or more oxides selected from the group comprising aluminium oxide, zirconium oxide, oxides of alkaline-earth metals and oxides of rare earth elements. The mass of all the alloying elements must be between 0.01 and 20 wt.% in terms of the total weight of the material medium. In a preferred embodiment, the doping of silicon dioxide is carried out using an aerosol as described in EP-A 995718. In accordance with this application, doping is performed by introduction of the aerosol into the flame, which is used for pyrogenic obtain silicon dioxide by oxidation in a flame or gidrol is for in flames, moreover, the spray contains salt or salt mixture of the alloying element or the element itself in dissolved or suspended form, or mixtures thereof. After the reaction in the flame of the gas flow allocate doped silicon dioxide. In the preferred embodiment, using the material of the carrier, which is alloyed with aluminum oxide in amounts that are within 0.05 and 1 wt.%.

Because silicon dioxide, intended for use in catalytically active coating in accordance with the present invention, has a low porosity, significantly suppressed the adsorption of hydrocarbons, which leads to primary poisoning ("clogged pores"). Thereby eliminating the secondary effects of aging due to burnout accumulated hydrocarbons and subsequent thermal damage to the catalyst. The advantage is that in the preferred embodiment, the material of the medium is acidic. Therefore, more difficult is the introduction of sulfur dioxide contained in the exhaust gases, in material media in the form of sulfates. The introduction of serosoderjaschei components included in exhaust gases of internal combustion engines, catalysts based on the reaction of the acid with the base and is observed mainly in the major cases which the materials of the media.

Thus, in a preferred embodiment, the catalyst in accordance with the present invention exhibits the following combination of features.

It includes a catalytically active coating on an inert ceramic or metal honeycomb structure, and this coating contains at least one platinum group metal selected from a range that includes platinum, palladium, rhodium and iridium, on fine-grained oxide material media. The oxide material of the carrier is a fine-grained silicon dioxide, preferably with one or more of (preferably all) of the following properties:

a) it consists of aggregates of essentially spherical primary particles having a mean diameter of between 15 and 60 nm,

b) specific surface area is within a 30 and 150 m/g,

in) maximum distribution of the pore radii greater than 20 nm,

g) total pore volume, the diameter of which is less than 30 nm, equal to less than 0.2 ml/g and

d) the pH value of the aqueous dispersion of the material of the carrier concentration of 4 wt.% is less than 6.

In the preferred embodiment, as the catalytically active component in the catalyst in accordance with the present invention, which is applied to the material of the carrier in a highly dispersed form by known methods, use p Atina.

In the catalytically active coating of the catalyst in accordance with the present invention may optionally include zeolites, which reduces the emission of hydrocarbons at low temperature exhaust gases. To ensure continuous combustion of adsorbed hydrocarbons, these zeolites may also be coated with platinum. Thus, zeolites also contribute to the reduction of the quantities of hydrocarbons that accumulate on the catalyst. Preferred zeolites include dealuminated Y-zeolite, beta zeolite and ZSM-5, the module of each of which exceeds 40. Module zeolite indicates the molar ratio therein between silicon dioxide and aluminum oxide. The higher the modulus, the lower the content in the zeolite alumina. Usually with the increase in module temperature resistance and stability to acid exposure increased.

The above-mentioned zeolites can be used alone, in combination with each other or in combination with other zeolites. In a preferred embodiment, the mass ratio between silicon oxide and the zeolite contained in the catalyst is in the range of 6:1 and 1:2. To guarantee continuous burning of hydrocarbons adsorbed by the zeolite, is enough in zeolites was attended by only a small portion of the total amount of platinum contained in the catalyst. It was found that for this purpose it is sufficient from 1 to 20 wt.% from the total amount of platinum contained in the catalyst.

The catalyst in accordance with the present invention includes an inert honeycomb structure, which is applied to a catalytically active coating. Cell structure acceptable to the catalyst include a ceramic structure (for example, made of cordierite) and metal patterns that are broadly used for purification of automobile exhaust gases. They are usually characterized by a cylindrical shape and having channels for the exhaust gas flow, which is to be cleaned passing through the entire length of the cylinder from one end to the other. The density of channels for the flow cross-sectional cellular structures called the density of cells. It usually is in the range of 40 and 250 see Catalytically active coating typically provide on the walls of the channels for flow, due to which it is in contact with a passing flow of exhaust gases.

For the catalytic activity of the catalyst is important content material catalytically active coating. The content is expressed as the concentration, i.e. in the form of a mass on the external volume of the honeycomb structure (g/l). In the preferred embodiment, this concentration is within 40 is 300 g/l volume of the honeycomb structure for just a catalytically active coating and between 0.01 and 8 g/l volume of the honeycomb structure for platinum group metals.

For the preparation of the catalyst in the preferred embodiment of the fine powdery material of the future catalytically active coating to prepare a slurry or a suspension for coating and it covers cell structure. Processing methods cell structures applying the catalytically active coating specialist in this field of technology is well known. In a preferred embodiment, a suspension of powdered materials prepared using the water.

Application of platinum group metals on the media materials (silicon dioxide, zeolites, and optional additional components can be performed during the production process in different periods. In a preferred embodiment, the platinum group metals is applied to the materials of the media before preparing a slurry for coating. This enables selective deposition of platinum group metals in different concentrations for different materials and media. So, for example, silicon dioxide platinum group metal may be applied in a higher concentration than the zeolite (zeolite).

For the deposition of platinum group metals on the powdered material carrier in a preferred embodiment, methods applied, which causes a high degree of dispersion of the metal circuit Board is a new group on the surfaces of materials, media and the particle size of fine crystals of metals within 1 and 50 nm, preferably between 2 and 20 nm. Especially acceptable methods are the saturation of the pore volume and homogeneous deposition.

During saturation of the pore volume of a given amount of material media predecessors of platinum group metals dissolved in the same amount of water, the volume of which corresponds to 70 to 110% in advance, the specific absorptivity of the material medium. The material of the carrier until it is sprayed with a solution of a platinum group metal, it is advisable to mix, for example, in the tank for coating. After completion of the process of saturation of the pore volume impregnated material of the carrier forms a powder, which, in spite of the contained water is still loose.

Homogeneous deposition is described, for example, in US No. 6103660. In this way the material of the carrier is suspended in water together with the connection-the precursor of platinum group metal. The injection of the basic or acidic solution into the suspension using a capillary (capillary injection) causes the precipitation of the compounds of the precursor on the surface of the material medium. In order to ensure uniform deposition throughout the volume of the suspension, basic or acidic solution is added slowly and stirring evenly distributed over the entire suspension.

Compound precursor metals PLA is inovas groups include all soluble compounds, that during calcination in air can be converted into the catalytically active components. Examples of such compounds include hexachloroplatinum acid, tetrachloroplatinate acid, diaminedichloroplatinum(II), tetraammineplatinum(II)chloride, ammonitenfauna(II), ammoniacloridegas(IV), platinumcontaining, tetraammineplatinum(II)nitrate, tetraammineplatinum(II)hydroxide, methylethanolamine(II)hydroxide, ethanolamine(IV)hexahydrate, platinum nitrate, allodiploid, palladium nitrate, diaminonaphthalene(II), tetraamminepalladium(II)hydroxide, rhodium chloride, rhodium nitrate and hexachloroiridium acid.

After impregnation and before additional processing catalytically active components can be fixed on a material carrier by calcination in air at temperatures in the range 200 and 600°C. It causes the decomposition of the compounds, the precursors of platinum group metals on oxides of various States of oxidation. The calcination can be performed, for example, in a rotary kiln. In a preferred embodiment, the calcination is conducted by spray calcination. During the spray calcination of the impregnated material is blown into the hot gas stream generated combusted methane, and calicivirus when the temperature of the gas from do 1000° With time and exposure to the gas stream from fractions of seconds to several minutes, for example, preferably from 0.1 s to 1 min, more preferably from 0.5 to 5 C. the Spray calcination powder is described in US no 6228292. However, the calcination before further processing of media materials with the catalyst is not always necessary.

In this way it is possible to apply coatings with a target of catalytically active platinum group metals on non-porous silicon dioxide, intended for use in accordance with the present invention, and other oxide materials carriers catalyst; usually platinum group metals applied in concentrations ranging from 0.01 to 10 wt.% in terms of the total weight of the material of the carrier and platinum group metals.

For application to a honeycomb structure of the coating thus prepared catalyst material is usually prepared aqueous suspension of these materials. Then, the honeycomb structure can be coated with this suspension using known methods, i.e., the coating being applied on the surface of the walls of which serve as partitions between the channels for streams. Next, the coating is dried at elevated temperatures and do not necessarily calicivirus in air at temperatures in the range 200 and 600°C. If necessary, obtained is thus the coating can be further impregnated additional compounds precursors of platinum group metals or base metals.

In the preparation of slurry for coating, it is advisable to use pyrogenic silicon dioxide, intended for use in accordance with the present invention, in agglomerated form with a bulk density in compacted state, more than 200 g/l, preferably above 500 g/l, and even more preferably greater than 600 g/L. In such agglomerated form processing in the preparation of suspensions for coating may be easier. In contrast, volumetric weight in compacted condition paglalarawan pyrogenic silicon dioxide is only less than 100 g/l, resulting in its processing involves problems of a technological nature.

Volumetric weight in the Packed state is a private mass and volume of the powder after the seal in sealing volumemute compliance with some conditions (see DIN ISO 787/XI). The concept of "primary particles, aggregates and agglomerates in the sense in which they are used in the description of the present invention, defined in the description DIN 53206, sheet 1.

It was found that the process of spray drying is particularly well-suited for agglomerating powdered fumed silicon dioxide. With this purpose, the powdered material using a known dispersing devices suspend the comfort in the water. For subsequent spray drying process acceptable suspension, the dry matter content of which is within 100 and 600 g/L. Such a suspension is imposed, for example, the spray dryer with the use of nozzles for two fluid and dried at temperatures in the range 200 and 450°C. the Average size of the particles so produced agglomerates is between 15 and 30 microns.

Alternatively, the above-described method in which the powdery material carriers initially introduced catalytically active platinum group metals and optional promoters, i.e. introducing the catalyst, and then put them on a honeycomb structure in the form of a coating, can also be applied to a honeycomb structure of the coating not containing catalysts materials media and then through impregnation coating, enter the platinum group metals and optional promoters. Also possible is the combination of both methods. For example, a coating of fumed silica and zeolites when the mass ratio between silica and zeolites from 6:1 to 1:2 can be impregnated platinumedition material with obtaining a catalytic Converter for cleaning exhaust gases, such as diesel engines.

Thanks acidity and low porosity materials media used in ka is alistore of the present invention, he absorbs from exhaust gases only small amounts of sulfur, and thus, a high degree of catalytic activity is maintained even after a long period of operation in the exhaust gases containing sulfur dioxide. Therefore, it is perfect for the oxidative purification of exhaust gases of diesel engines. For example, when, after aging in an oven as described in example 1, through the catalyst missed artificial exhaust gases from 85 objact./million of sulfur dioxide, was found less than 0.25 wt.% sulfur dioxide, calculated on the total weight of the catalyst, including cell structure and floor. After aging in the engine for 45 h as described in application example 2, used diesel fuel with 2400 miscast./million of sulfur, were also found less than 0.25 wt.% sulfur dioxide, calculated on the total weight of the catalyst, including cell structure and floor. Moreover, the specific surface area of this catalyst was decreased less than 20% compared with its value before aging.

The essence of the present invention in more detail, explain the following examples and research. However, they are not restrictive.

EXAMPLES

Study materials media

Various metal oxides used in the following catalysts, ohar karisafili such as their specific surface area, pore structure and acidity. Acidity was determined as the pH value of the aqueous dispersion of the material of the carrier with 4 wt.% material media in terms of the total weight of this dispersion. The results are presented in table 1.

Table 1.
The results okharakterizovanie metal oxides, such as specific surface area, porous structure and value of the pH of the aqueous dispersion
No.Material mediaSpecific surface area [m2/g]The maximum distribution of the pore radii [nm]The volume of pores with a size of<30 nm [ml/g]The pH value of the aqueous dispersion concentration of 4 wt.%
1Al2About3134100,478,0
2Al2O3/SiO2*)3116,50,657.7
3Al2About3/SiO2*)153100,507,5
4SiO223410 5,2
5SiO215910,50,75of 5.4
6SiO265450,09the 4.7
*)the aluminosilicate with 5 wt.% SiO2

Material carrier No. 6 meets catalyst in accordance with the present invention. He is pyrogene prepared material carrier with an average size of primary particles of 40 nm. Its specific surface area is relatively small in comparison with the same parameter materials of the carriers # 1 to # 5. Small surface area due to its low porosity, which is expressed by the distribution of the pore radii, and a small amount of mesopores. The pH value of this material in water dispersion concentration of 4 wt.% is in the acidic range (pH 4,7). The result is a significantly reduced number of applied sulfur dioxide or sulfur trioxide, which are also acidic. Thus, the catalyst on the basis of the material of the carrier is resistant to exhaust gases containing sulfur dioxide.

In each of the following examples and comparative examples, the catalytic coating was applied on two different cell structure from the internal pores (cell structure of the type 1 and the honeycomb structure-type 2). The characteristics of these cell structures are presented in table 2.

Table 2
Characteristics used honeycomb structures
TypeMaterialDiameter [cm]Length [cm]The density of cells [cm-2]Wall thickness [mm]
1Cordierite11,837,6620,2
2Cordierite11,8315,24620,16

Comparative example 1

From a mixture of two powders, including as a catalytic component of platinum were prepared by two catalyst.

In the preparation of the powder 1 in the tank for the coating material was downloaded 1 kg of the material of the carrier # 3 (aluminosilicate). Absorptivity of the aluminosilicate was 800 ml/kg of This aluminosilicate continuously stirred while its spraying with 766 ml of an aqueous solution ethanolamine(IV)hexahydroxy ((EA)2Pt(OH)6, (HO-C2H4-NH3)2+PtIV(OH)6) at a flow rate of 56 ml/(kg·min). Wet the powder, still retained the flowability was caliciviral its injection into the stream of sorrow is his gas, obtained by the combustion of methane. The calcination was carried out at the temperature of the gas 780°and the exposure time in this gas stream is about one second (spray calcination).

The content of platinum in the thus prepared Pt-alumina powder (powder 1) amounted to 2.79 wt.%. A sample of this material was studied under transmission electron microscope. Figure 1 presents a photograph of the structure of this catalytic material.

In the preparation of the powder 2 in the tank for the coating material was downloaded 1 kg Y-zeolite having the module 60. Absorptivity of this zeolite was 1350 ml/kg of Y-zeolite was continuously stirred while its spraying with 242 ml of an aqueous solution ethanolamine(IV)hexahydroxy when the volumetric flow rate of 56 ml/(kg·min). Wet the powder, still retained the flowability was caliciviral as stated in the case of the powder 1.

The content of platinum in Pt-zeolite powder (powder 2) was 0.88 wt.%.

Six mass parts powder to 1 and one mass part of the powder 2 suspended in water and homogenized by grinding in a ball mill. The dry matter content in the finished slurry for coating was 35 wt.%. The pH value of the slurry for coating was 6.5.

By immersion in a suspension for the bearing cover on one cell type structure 1 and the cellular structure of the type 2 was coated using 126 g of dry matter per liter of volume of the honeycomb structure. The coating was dried in air at 120°was caliciviral in air at 300°C for 4 h and finally restored in the current shielding gas mixture of hydrogen and nitrogen (95% vol. N2and 5% vol. H2) for 2 h at 500°C.

The content of platinum in the finished catalyst was 3,17 g per liter of volume of the catalyst.

Important conditions for preparation of the catalyst of this and the following examples are summarized in table 3.

Comparative example 2

Similarly to comparative example 1 was prepared by two of the comparative catalyst. In contrast to comparative example 1 in powder 1 used the material of the carrier # 2 with twice the specific surface area (5 wt.% silicon oxide, specific surface area: 311 m2/g).

Comparative example 3

Similarly to comparative example 1 was prepared by two of the comparative catalyst. In contrast to comparative example 1 in powder 1 used material carrier No. 1 (pure aluminum oxide) with a specific surface area of 134 m2/year

Comparative example 4

Similarly to comparative example 1 was prepared by two of the comparative catalyst. In contrast to comparative example 1 in powder 1 used silicon dioxide with a specific surface area of 234 m/g (material carrier No. 4).

Example 1

And the mixture of two powders, as a catalytic component containing platinum were prepared by two catalyst.

In the preparation of the powder 1 in the tank for the coating material was downloaded 1 kg of material media No. 6 (low-porosity silicon dioxide) with a specific surface area of 65 m2/, Absorptivity this low-porosity silicon dioxide was 500 ml/kg. This silicon dioxide was continuously stirred while its spraying with 445 ml of an aqueous solution ethanolamine(IV)hexahydroxy when the volumetric flow rate of 56 ml/(kg·min). Wet the powder, still retained the flowability was caliciviral its injection into the stream of hot gas produced by combustion of methane. The calcination was carried out at the temperature of the gas 780°and the exposure time in this gas stream is about one second (spray calcination).

The content of platinum in the thus prepared Pt-silica powder (powder 1) amounted to 2.79 wt.%. A sample of this material was studied under transmission electron microscope. Figure 2 presents a photograph of the structure of this catalytic material. It can clearly be seen essentially spherical structure of pyrogenic material media. Spherical particles are dense, free from pores and possess a smooth surface on which cards are the new particles (black spots). This structure is preserved, even if the material is subjected to subsequent processing, and it is still possible to determine in the finished catalytic coating.

From examining figure 2 it immediately becomes clear that the specific surface area of the material of the carrier is caused only by geometrical surface of spherical particles. In contrast, the material of the carrier of figure 1 is characterized by a complex structure with a large specific surface area.

As the second catalyst powder used powder 2 comparative example 1.

Six mass parts powder to 1 and one mass part of the powder 2 suspended in water and homogenized by grinding in a ball mill. The dry matter content in the finished slurry for coating was 35 wt.%. The pH value of the slurry for coating was equal to 5.1.

Similarly to comparative example 1 two monolithic honeycomb structure produced by coating using 126 g of dry matter per liter of volume of the honeycomb structure.

The coating was dried in air at 120°was caliciviral in air at 300°C for 4 h and finally restored in the current shielding gas mixture of hydrogen and nitrogen for 2 h at 500°C.

The content of platinum in the finished catalyst was 3,17 g per liter of the volume of produce is RA.

Example 2

From a mixture of two powders, as a catalytic component containing platinum were prepared by two catalyst.

As a first catalytic powder used powder 1 of example 1.

In the preparation of the powder 2 in the tank for the coating material was downloaded 1 kg of a mixture consisting of 500 g of Y-zeolite with module 60 and 500 g of zeolite ZSM-5 with module>400. Water-absorbing capacity of this zeolite mixture was 1180 ml/kg Zeolite mixture is continuously stirred while it is sprayed with 320 ml of an aqueous solution ethanolamine(IV)hexahydroxy when the volumetric flow rate of 56 ml/(kg·min). Wet the powder, still keeping flowability, did not illnerova, and used directly in the preparation of slurry for coating.

The content of platinum in Pt-zeolite powder (powder 2) was 0.50 wt.%.

of 2.2 parts by weight of the powder 1 and the mass portion of the powder 2 suspended in water and homogenized by grinding in a ball mill. The dry matter content in the finished slurry for coating was 35 wt.%. The pH value of the slurry for coating was equal to 4.9.

Similarly to comparative example 1 two monolithic honeycomb structure (type 1 and type 2) were made by coating using 97 g of dry matter per liter of cell volume with the touch.

The coating was dried in air at 120°was caliciviral in air at 300°C for 4 h and finally restored in the current shielding gas mixture of hydrogen and nitrogen for 2 h at 500°C.

The content of platinum in the finished catalyst was 3,17 g per liter of volume of the catalyst.

Example 3

Analogously to example 2 was prepared two catalyst. In contrast to example 2, the powder 1 is not subjected to the spray calcination, but when it is further processed in the preparation of slurry for coating, and powder 2 were wet.

Example 4

Analogously to example 2 was prepared two catalyst. In contrast to example 2, the concentration of platinum powder 1 was 2.52 wt.%.

In the preparation of a dispersion for coating used to 1.2 parts by weight of the powder 1 and the mass portion of the powder 2. Similarly to comparative example 1 three monolithic honeycomb structure produced by coating using 66 g of dry matter per liter of volume of the honeycomb structure.

The content of platinum in the finished catalyst was 1.06 g per liter of volume of the catalyst.

Example 5

Analogously to example 2 was prepared two catalyst. In contrast to example 2 for the preparation of the powder 1 and powder 2 as platypodinae predestin the ka used tetraammineplatinum(II)nitrate [Pt(NH 3)4](NO3)2.

Example 6

Analogously to example 2 was prepared two catalyst. In contrast to example 2 for the preparation of the powder 1 and powder 2 as platypodinae predecessor used tetraammineplatinum(II)hydroxide [Pt(NH3)4](OH)2.

Table 3
The composition and conditions of preparation of the investigated catalysts
ExampleOxide mediaZeolitePlatinum SolConcentration [g/l]The mass ratio of Pt-oxide media/Pt-zeolitePlatinum concentration [g/l]Calcining the powder of Pt-oxide media
SPRNo. 3Y-zeolite, module: 60(EA)2Pt(OH)61266:13,17The spray calcination
SPRNo. 2Y-zeolite, module: 60(EA)2Pt(OH)61266:13,17The spray calcination
SprtNo. 1Y-zeolite, module: 60(EA)2Pt(OH)6126 6:13,17The spray calcination
SPRNo. 4Y-zeolite, module: 60(3A)2Pt(OH)61266:13,17The spray calcination
App.1No. 6Y-zeolite, module: 60(3A)2Pt(OH)61266:13,17The spray calcination
PRNo. 6Y-zeolite, module: 60 ZSM-5, module:>400(3A)2Pt(OH)697a 2.2:13,17The spray calcination
PRNo. 6Y-zeolite, module: 60 ZSM-5, module:>400(3A)2Pt(OH)697a 2.2:13,17Did not
PRNo. 6Y-zeolite, module: 60 ZSM-5, module:>400(EA)2Pt(OH)6661,2:11,06The spray calcination
PRNo. 6Y-zeolite, module: 60 ZSM-5, module:>400[Pt(NH3)4](NO3)297a 2.2:1You have crucified the preliminary calcination
PRNo. 6Y-zeolite, module: 60 ZSM-5, module:>400[Pt(NH3)4](NO3)297a 2.2:13,17The spray calcination

Application example 1

The catalytic activity of the catalysts of the above examples when cleaning the exhaust gas were determined using modeling gas test installation. This setup is able to simulate all gaseous components of the real exhaust gas of a diesel engine. The test conditions and the composition of the model gas can be gleaned from table 4. As the hydrocarbon component used propene.

Table 4
The test conditions and the composition of the model gas to determine the speed of turning toxic components CO, HC, NOxand SO2in simulating gas test installation.
ComponentConcentration
CO350(objact./million)
H2117(objact./million)
With3H690(part./mn3)
SO2 20(objact./million)
NO270(objact./million)
About26(vol.%)
H2About10(vol.%)
CO210,7(vol.%)
N2rest
gas consumption1950(Nl/h)*
the amount of catalyst⊘25×76 mm
the volumetric rate50000(h-1)
the heating rate15(°C/min)
* l/h under normal conditions (pressure: 101.3 kPa, temperature: 0°).

For determination of gaseous components included in the exhaust gas, used measuring instruments listed in table 5.

Table 5:

List of measuring equipment used to determine the concentration of exhaust gases in simulating gas test installation
The designated gasThe measuring deviceManufacturer
About2Oxymatiemens AG
hydrocarbonFIDPierburg Meβtechnik
NOxCDL 700 ElhtZellweger ECO-Systeme
COBinosRosemount
CO2BinosRosemount
SO2BinosRosemount

The measurements were carried out on fresh catalysts, and the catalysts after aging (aging in the oven: 48 h at 350°flow model of exhaust gases: volume speed: 15000 h-1; 10 vol.% H2O, 10% vol. About2, 10% vol. CO2, 85 objact./million SO2, 270 objact./million NO rest - N2).

To determine the moment of reaching the operating temperature of the exhaust gases was heated with a speed of 15°C/min

To calculate the rate of conversion used the following formula:

where X denotes the rate of conversion [%];

NEdenotes the concentration of toxic component before entering the catalyst [objact./million];

NAdenotes the concentration of toxic component after exiting the catalyst [objact./million].

The results of determination as in the fresh catalysts, and the catalysts after aging are summarized in table 6. Table 6 shows the concentration of sulfur in rolled is Torah after aging, which was determined post-program analysis using the combined method of combustion/infrared spectrometry (company LECO Instruments).

Data in table 6 clearly show that in contrast to the comparative catalysts of comparative examples SPR on SPR catalysts of the present invention prepared in the examples with PR1 on PR, show excellent resistance to the action of serosoderjaschei components. This becomes evident from the very low level of absorption of sulfur catalysts of the present invention, on the one hand, and at the same time excellent catalytic activity after aging, on the other hand.

Table 6
The catalytic activity of the catalysts of examples in the fresh state and after aging in an oven, as well as the absorption of sulfur catalysts after aging
CatalystsFreshAfter aging1
T50,CO[°]2T50,HC[°]T50,CO[°]T50,NA[°]Conc. S [%]3
SPR144158161174 0,90
SPR1551691852011,50
SPR1491661691891,20
SPR1521651701820,61
PR11451551461550,10
AC21411521411530,10
AC31441551441570,10
PR1851931861930,08
WP51531621551640,10
PR1511581531590,11
1Aging in an oven for 48 h at 350°in the flow model of the exhaust gas; the volumetric rate: 15,000 h-1; 10 vol.% H2Oh, 10% vol. About2, 10% vol. CO2, 85 objact./million SO2, 270 objact./million NO rest - N2
2The catalytic activity of the catalysts described in t is called to operating temperature, when turning incur a 50% toxic components
3Determining the concentration of sulfur in the catalyst after aging post-program analysis using the combined method of combustion/infrared spectrometry (company LECO Instruments).

Application example 2

In the second example of application of the defined catalytic activity when cleaning exhaust gas catalysts of the above examples both in the fresh state and after aging in the flow of exhaust gases real diesel engine. Aging was carried out by repeated iteration of the loop of aging presented in figure 1. Aging was carried out in conjunction with modern automotive diesel engine with a working volume of 1.9 liters For such aging process used diesel fuel containing 2400 miscast./million of sulfur, which is 10 times more than conventional diesel fuels. This ensured a much more rapid aging of the catalysts. The results of the evaluation of catalytic activity and physico-chemical data of the investigated catalysts correspond obtained in the actual aging of the catalyst after a mileage of about 30000 km Such aging is typical for catalysts subjected to aging while driving in real traffic.

analiticheskoy activity was determined by carrying out the so-called test on the engine with variation of temperature. To this end, the catalyst was first kondicionirovanie in diesel exhaust gases within 5 min at a temperature of exhaust gas 100°C. Then performed a step test, in which every 20 min the exhaust gas temperature was increased by 10°C. increasing the temperature of exhaust gases was achieved by increasing the load on the engine.

The working temperature of the investigated catalysts in the fresh state and after aging are presented in table 7 in the form of values of the temperature T50for CO and HC.

Table 7 also provides additional physico-chemical post-program data for catalysts after aging. The sulfur concentration was determined by the LECO method, and the specific surface area was determined by BET method according to DIN 66131.

The data of table 7 show that aging when the engine is hardly reduces the catalytic activity of the catalysts of the present invention prepared in examples from PR 1 to PR, whereas the comparative catalysts of comparative examples SPR on SPR demonstrate a significant reduction in catalytic activity. Physico-chemical analysis shows that this deterioration is due to a decrease in the specific surface area caused by clogged pores"adsorbed hydrocarbons and implementation of large quantities to the market, which is the catalytic poison. Thanks to the chemical characteristics and morphology of the materials used media, the catalysts of the present invention prepared in the examples with PR1 on PR, these effects do not show.

201
Table 7
Catalytic activity and physico-chemical characteristics of the catalysts of examples in the fresh state and after aging when the engine (45 h using diesel fuel containing 2400 miscast./million sulfur)
CatalystFreshAfter aging
T50,CO[°]1T50,HC[°]BET [m2/g2]T50,CO[°]T50,HC[°]BET [m2/g]Conc. S [%]3
SPR11016833154193230,98
SPR12517351175208181,47
SPR11517631165221,37
SPR12317145166197330,71
PR111417336115176360,10
AC211017036110175360,10
AC311217035113172350,09
PR13519129137194290,07
WP512118235123185350,09
PR12017935122182360,10
1The catalytic activity of the catalysts described in the so-called working temperature at which the transformation are 50% toxic components
2The determination of the specific surface area of catalysts using the method of BET
3Determining the concentration of sulfur in the catalyst after aging post-program analysis using the combined method of combustion/infrared spectrometry (company LECO Instruments).

1. Catalyst for cleaning exhaust gases of an internal combustion engine, comprising a catalytically active coating on an inert ceramic or metal honeycomb structure, where the coating contains at least one platinum group metal selected from a range that includes platinum, palladium, rhodium and iridium, on fine-grained oxide material of the carrier, and the oxide material of the carrier is an essentially non-porous material based on silicon dioxide and includes aggregates of essentially spherical primary particles having a mean diameter of between 7 and 60 nm, and the value of pH of the aqueous dispersion of this material at a concentration of 4 wt.% is less than 6.

2. The catalyst according to claim 1, in which the average diameter of the primary particles of the oxide of the material of the carrier is within a 20 and 50 nm.

3. The catalyst according to claim 2, in which the maximum distribution of the radii of the pores of the oxide material of the carrier is greater than 20 nm.

4. The catalyst according to claim 3, in which the oxide material of the carrier has a pore volume in which the volume of pores with diameter less than 30 nm is less than 0.2 lhs.

5. The catalyst according to claim 1, in which the material of the medium alloyed with one or more oxides selected from the group comprising aluminium oxide, zirconium oxide, oxides of alkaline-earth metals and oxides of rare earth elements, and in which the total mass of all the alloying elements is between 0.01 and 20 wt.% in terms of the total weight of the material medium.

6. The catalyst according to claim 5, in which the material of the medium alloyed aluminum oxide in amounts that are within 0.05 and 1 wt.%.

7. The catalyst according to claim 1, in which the oxide material of the carrier is a silicic acid obtained pyrogene by oxidation in a flame or hydrolysis in the flames.

8. The catalyst according to claim 1, in which one of the metals of the platinum group is platinum.

9. The catalyst according to claim 8, in which the catalytically active coating further includes one or more of zeolite on which platinum is contained in a highly dispersed form.

10. The catalyst according to claim 9, in which one of the zeolites is dealuminated Y-zeolite, beta zeolite or zeolite ZSM-5, the module of each of which exceeds 40.

11. The catalyst according to claim 9, in which the mass ratio between the oxide material of the carrier and zeolite (zeolite) is from 6:1 to 1:2.

12. The catalyst according to claim 9, in which at least 1 wt.%, but not bol is more a maximum of 20 wt.% from the total amount of platinum contained in the catalytically active coating, is present in the zeolite (zeolite).

13. The catalyst according to claim 1, in which the catalytically active coating contained on a cell structure in a concentration of from 40 to 300 g/l volume of the honeycomb structure

14. The catalyst according to item 13, in which the platinum group metals are contained in a concentration of from 0.01 to 8 g/l volume of the honeycomb structure.

15. The catalyst according to claim 1, in which the oxide material of the carrier has the following properties:

a) it consists of aggregates of essentially spherical primary particles having a mean diameter of between 15 and 60 nm,

b) specific surface area is within a 30 and 150 m2/g

in) maximum distribution of the pore radii greater than 20 nm,

g) total pore volume, the diameter of which is less than 30 nm, equal to less than 0.2 ml/g and

d) the pH value of the aqueous dispersion of the material of the carrier concentration of 4 wt.% is less than 6.

16. The catalyst according to item 15, in which the specific surface area of silica is less than 100 m2/year

17. The catalyst 15, which additionally comprises one or more zeolites, and in which the mass ratio between silicon oxide and the zeolite is in the range from 6:1 to 1:2.

18. The catalyst 17 in the cat the rum platinum group metal comprises platinum, moreover, this contains platinum on silica, and zeolite (zeolite), where at least 1 wt.%, but no more, a maximum of 20 wt.% from the total amount of platinum contained in the catalyst is present on the zeolite (zeolite).

19. The method of preparation of a catalyst for cleaning exhaust gases of an internal combustion engine, comprising a catalytically active coating on an inert ceramic or metal honeycomb structure, and the said coating contains at least one platinum group metal selected from a range that includes platinum, palladium, rhodium and iridium, on fine-grained oxide material of the carrier, where the oxide material of the carrier is an essentially non-porous material based on silicon dioxide and includes aggregates of essentially spherical primary particles having a mean diameter of between 7 and 60 nm, and this method includes a step of coating on a honeycomb structure coating the use of suspension for coating comprising an oxide material of the carrier, where the oxide material of the carrier in the preparation of suspensions for coating used in spray dried form in which it has a bulk density in compacted state, more than 200 g/L.

20. The method according to claim 19, in which the volumetric weight in compacted state the AI is more than 500 g/L.

21. The method according to claim 19, in which at least one platinum group metal is applied on the oxide material of the carrier before preparing a slurry for coating.

22. The method according to item 21, in which the suspension for coating additionally comprises one or more zeolites when the mass ratio between the oxide material of the carrier and zeolite (zeolite) from 6:1 to 1:2.

23. The method according to item 22, in which at least one platinum group metal comprises platinum.

24. The method according to item 23, which contains platinum on the zeolite (zeolite) in an amount of from 1 to 20 wt.% in terms of the total number of platinum on the oxide material of the carrier and the zeolite (zeolite).

25. The method according to claim 19 or 20, in which after application to a honeycomb structure of the coating using a suspension for coating containing an oxide of the material of the carrier, provided with a coating of a honeycomb structure is dried and calicivirus in the future thus prepared is supplied by coating a honeycomb structure is impregnated with a precursor of at least one platinum group metal.

26. The method according A.25, in which at least one platinum group metal comprises platinum.

27. The method according to p, in which the suspension for coating additionally comprises one or more zeolites when the mass ratio of the sydnaya material media and zeolite (zeolite) from 6:1 to 1:2.



 

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41 cl, 3 dwg, 8 tbl, 10 ex

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3 ex

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10 cl, 3 tbl, 15 ex

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5 cl, 1 tbl, 6 ex

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31 cl, 5 dwg, 3 tbl, 15 ex

FIELD: petrochemical process catalyst.

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16 cl, 5 dwg, 1 tbl, 6 ex

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2 tbl, 9 ex

FIELD: preparation of cerium-containing catalysts modified by palladium on granulated and monolithic carriers.

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2 cl, 1 tbl, 8 ex

FIELD: alternate fuel production.

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EFFECT: reduced catalyst preparation time and improved environmental condition.

1 tbl, 10 ex

FIELD: petrochemical processes.

SUBSTANCE: catalyst, containing high-silica zeolite of the H-ZSM-5 type having silica modulus SiO2/Al2O3 = 20 to 160 in amount 60.0-90.0%, contains (i) as modifying component at least one oxide of element selected from group: boron, phosphorus, magnesium, calcium, or combination thereof in amount 0.1-10.0 wt %; and (ii) binding agent: alumina. Catalyst is formed in the course of mechanochemical and high-temperature treatments. Described is also a catalyst preparation process comprising impregnation of decationized high-silica zeolite with compounds of modifying elements, dry mixing with binder (aluminum compound), followed by mechanochemical treatment of catalyst paste, shaping, drying, and h-temperature calcination. Conversion of methanol into olefin hydrocarbons is carried out in presence of above-defined catalyst at 300-550°C, methanol supply space velocity 1.0-5.0 h-1, and pressure 0.1-1.5 mPa.

EFFECT: increased yield of olefin hydrocarbons.

3 cl, 1 tbl, 15 ex

FIELD: petroleum processing and catalysts.

SUBSTANCE: invention relates to catalyst for steam cracking of hydrocarbons, which catalyst contains KMgPO4 as catalyst component. Catalyst is prepared by dissolving KMgPO4 precursor in water and impregnating a support with resulting aqueous solution of KMgPO4 precursor or mixing KMgPO4 powder or its precursor with a metal oxide followed by caking resulting mixture. Described is also a light olefin production involving steam cracking of hydrocarbons.

EFFECT: increased yield of olefins, reduced amount of coke deposited on catalyst, and stabilized catalyst activity.

21 cl, 4 tbl, 14 cl

FIELD: hydrocarbon conversion processes and catalysts.

SUBSTANCE: invention, in particular, relates to selectively upgrading paraffin feedstock via isomerization. Catalyst comprises support and sulfated oxide or hydroxide of at least one of the elements of group IVB deposited thereon; a first component selected from group consisting of consisting of lutetium, ytterbium, thulium, erbium, holmium, and combinations thereof; and a second component comprising at least one platinum-group metal component. Catalyst preparation process comprises sulfating oxide or hydroxide of at least one of the elements of group IVB to form sulfated support; depositing the first component onto prepared support; and further depositing the second component. Invention also relates to hydrocarbon conversion process in presence of above-defined catalyst.

EFFECT: improved catalyst characteristics and stability in naphta isomerization process to increase content of isoparaffins.

13 cl, 2 dwg, 1 tbl

FIELD: chemical industry; methods of manufacture of the deposited polymetallic catalytic agents.

SUBSTANCE: the invention is pertaining to the methods of manufacture of the oxidation catalytic agents based on any solid carriers by deposition on them of the metals solid solutions. The catalytic agents may be used in the various fields of the catalysis, for example, for realization of the photocatalytic, electrocatalytic, catalytic and other reactions. The invention presents the description of the method of manufacture of the deposited polymetallic catalytic agents by deposition of the metals on ceramics, plastics materials, metals, composite materials, oxides of the transition metals, the carbonic material, which includes the sequential stages of deposition of the previous layers carrying the cationic and anionic parts and for recovery. In the capacity of the previous layer carrying the cationic part use the substances of the following composition: [М(NH3)xАyz, where M - Cr, Со, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Cd, Ir, Pt, Au; А - ОН, Н20, C1, Br, I, NO, NO2; В - OH, F, Cl, Br, I, NO2, NO3, SO4; and as the previous layer carrying the anionic part use the substance of the following composition: Еx2[M'Dy2Cz2], where М' - Ti, Cr, Со, Ni, Cu, Zn, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg; С - ОН, Н20, F, SCN, Cl, Br, I, NO, NO2; D - ОН, Н20, F, SCN, Cl, Br, I, NO, NO2; Е - Н, Li, Na, К, Rb, Cs, NH4; or as the previous layer carrying the cationic part use the substances having the following composition: [М(NH3)xАyz and/or [М1(NH3)x1Аy1z1, where M AND M1 - Cr, Со, Ni, Cu, Zn, Ru, Ag, CD, Ir, Pt, Au; А - ОН, Н20, C1, Br, I, NO, NO2; В - OH, F, Cl, Br, I, NO2, NO3, SO4; and as the previous layer carrying the anionic part use the substances having the following composition: Еx2[M'Dy2Cz2] and/or Еx3[M'1Dy3Cz3], where М' and М'1 - Ti, Cr, Со, Ni, Cu, Zn, Zr, Nb, Mo, Tc, Ru, Ag, Cd, Hf, Ta, W, Os, Ir, Pt, Au, Hg; С - ОН, Н20, F, Cl, Br, I, NO, NO2; D - ОН, Н20, F, Cl, Br, I, NO, NO2; Е - Н, Li, Na, К, Rb, Cs, NH4; or as the previous layer carrying both the cationic part and then anionic part use the substance having the following composition: [М(NH3)xАy]x1[M'Dy1Cz1]z, where: M - Cr, Со, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Cd, Ir, Pt, Au; А - ОН, Н20, C1, Br, I, NO, NO2; М' - Ti, Cr, Со, Ni, Cu, Zn, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, 0s, Ir, Pt, Au, Hg; С - ОН, Н20, F, Cl, Br, I, NO, NO2; D - ОН, Н20, F, Cl, Br, I, NO, NO2. The technical result of the invention is the high activity of the produced catalytic agents.

EFFECT: the invention ensures the high activity of the produced catalytic agents.

14 cl, 3 tbl, 97 ex

FIELD: petrochemical process catalysts.

SUBSTANCE: invention relates to molded particles having particular shapes. They can be used to prevent or considerably reduce contamination in catalyst beds operated in flows carrying contaminating materials, which results in loss of pressure within a bed. Oblong molded particles for catalysts and granulometric compositions contain three raised portions, each extending from central segment aligned from central longitudinal axis of particle and attached to central segment, while cross section of particle occupies area surrounded by outer frontiers of six circles surrounding central circle minus area of three alternate outer circles. Each of six outer circles has diameter ranging from 0.74 to 1.3 diameters of central circle and touches two neighboring outer circles, while three alternate outer circles are situated at equal distance from the central circle, have the same diameter, and are essentially in contact with central circle. These are the particles that are contained in protective layer. Method of reducing contamination or effect of contaminating precipitation in catalyst beds comprises contacting feedstock containing contaminating material with one or several layers of above-described particles. Disclosed are also method of converting organic feedstock, method for obtaining middle distillates from synthesis gas, and a method of converting hydrocarbons in particular of described particles.

EFFECT: considerably reduced catalyst-poisoning effect of contaminating materials contained in feedstock.

15 cl, 1 dwg, 1 tbl

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