Composition based on zirconium oxide, titanium oxide or mixed zirconium and titanium oxide, deposited on silicon oxide support, methods of producing said composition and use thereof as catalyst. RU patent 2448908.

FIELD: chemistry.

SUBSTANCE: invention can be used in inorganic chemistry. The catalytic composition contains at least one oxide on a support, which is based on zirconium oxide, titanium oxide or a mixed zirconium and titanium oxide, deposited on a silicon oxide-based support. After firing at 900°C for 4 hours, the oxide on the support has the form of particles deposited on a support and size of said particles is not greater than 5 nm if the oxide on the support is based on zirconium oxide, not greater than 10 nm if the oxide on the support is based on titanium oxide and not greater than 8 nm if the oxide on the support is based on a mixed zirconium and titanium oxide. After firing at 1000°C for 4 hours, particle size is not greater than 7 nm if the oxide on the support is based on zirconium oxide, not greater than 19 nm if the oxide on the support is based on titanium oxide and not greater than 10 nm if the oxide on the support is based on a mixed zirconium and titanium oxide.

EFFECT: invention reduces aggregation of particles and sintering thereof at high temperature.

11 cl, 1 tbl, 9 ex

The present invention relates to a composition based on zirconium oxide, titanium oxide or a mixed oxide of zirconium and titanium supported on a carrier of silica, the means of its production and its use as a catalyst.

Catalysts often consist of an active phase which is a phase with desired catalytic properties, and the media, which caused the aforementioned active phase. For catalyst efficiency is important that the active phase was more finely dispersed on the carrier, so that this active phase was on a carrier in the form of finely dispersed, not subjected to aggregation of particles. In addition, since the catalysts are often exposed to high temperatures, it is also necessary to finely dispersed state of the active phase was preserved even at this temperature. In other words, should not occur sintering of particles.

The aim of the present invention is to develop catalysts that meet these requirements.

For such purpose, the composition according to the invention in accordance with the first embodiment contains at least one oxide on the carrier obtained on the basis of zirconium oxide, titanium oxide or a mixed oxide of zirconium and titanium supported on a carrier of oxidative, and is characterized by the fact that after firing at 900°C for 4 hours, the oxide on the carrier is in the form of particles deposited on said media, which are:

not more than 5 nm, if the oxide on the carrier obtained on the basis of zirconium oxide;

not more than 10 nm, if the oxide on the carrier obtained on the basis of titanium oxide;

not more than 8 nm, if the oxide on the carrier obtained on the basis of a mixed oxide of zirconium and titanium.

According to the second variant implementation, the composition contains at least the following components: the same type of oxide on the media, the same media type, and differs in that after firing at 1000°C for 4 hours, the oxide on the carrier is in the form of particles deposited on said media, which are:

not more than 7 nm, if the oxide on the carrier obtained on the basis of zirconium oxide;

not more than 19 nm, if the oxide on the carrier obtained on the basis of titanium oxide;

not more than 10 nm, if the oxide on the carrier obtained on the basis of a mixed oxide of zirconium and titanium.

Other distinctive features, details and advantages of the present invention become more deeply understood upon reading the following further description and specific examples are intended for illustration only and are not restrictive.

Under rare earth element understand the elements from the group consisting the th of yttrium and elements of the Periodic system, with atomic number lying in the range from 57 to 71 inclusive.

In continuation of the present description under understand specific surface the specific surface according to BET, defined by nitrogen adsorption in accordance with ASTM D 3663-78 established on the basis of the method of brunauer, Emmett and teller described in The Journal of the American Chemical Society, 60, 309 (1938).

In addition, calcination at a given temperature for a specified time, unless the opposite, firing in the air after establishing a constant temperature within the indicated time.

The composition according to the invention contains an oxide on a substrate in the form of particles of nanometric size, the mentioned particles supported on a carrier. Thus, the oxide particles on the media are mostly located on the surface of said carrier, thus assume that the particles can be inside the pores of the support, however, remain on the surface.

This oxide on the substrate, first and foremost, can be a zirconium oxide without additives, i.e. a simple oxide in the form of ZrO₂.

The oxide on the substrate may also be a doped zirconium oxide, i.e. it can be obtained on the basis of zirconium oxide and at least one oxide of another element M selected from among the praseodymium is, lanthanum, neodymium and yttrium. In this case, the zirconium oxide ZrO₂is a major or dominant component, whereas the element or elements M is the rest of oxide on the carrier.

The content of the element M is not more than 50 wt.%, moreover, the zirconium oxide is at least 50 wt.% oxide on the carrier. This value content, expressed as weight of oxide of the element M or set of elements of M with respect to the weight of the entire oxide on the carrier (zirconium oxide and oxide(s) item(s) M). The value of the content of the element M may vary in a wide interval, in particular, it may be in the range from 5 to 40%, more preferably from 10% to 40%. This value is particularly preferably may lie in the range from 10% to 30%.

The oxide on the carrier can also be a titanium oxide TiO₂.

In addition, the oxide on the carrier may be a mixed oxide of zirconium and titanium. The mixed oxide in this case it is necessary to understand the solid solution of oxides of titanium and zirconium in the form of pure crystallographic phase with the structure ZrTiO₄. In this case, the analysis of the product using the method of x-ray diffraction (RD) does not allow to establish the existence of different patterns, in addition to ZrTiO₄. This structure corresponds to the card 34-415 joint Committee on STD the mouths powder diffraction (JCPDS). Such solid solution is generally in a state in which the proportion of titanium oxide relative to the total weight of the mixed oxide may be in the range from 30 wt.% up to 40 wt.%.

Here it should be noted that the composition may contain several types of oxides on the carrier, i.e. to simultaneously contain particles of zirconium oxide, particles of titanium oxide and particles of mixed oxide.

The oxide on the carrier is in crystalline form.

The oxide on the carrier is in the composition according to the invention in the form of particles of nanometric size.

It should be noted that the oxide particles on the carrier can either be solid or may be in the form of units.

The values of the dimensions given in this description represent the average values of the dimensions specified way RD. The value measured by the method of EP corresponds to the size of the domain of coherence calculated from the width of the three most intense diffraction beams in the spatial group x, y, z using the model of Debye-sherrer.

Above were given the particle size of the oxide on the carrier depending on the type of oxide on the carrier and calcining the composition. Here it should be noted that the values given for the composition subjected to calcination at 1000°C (the second option exercise), can be applied to the composition is, which was previously subjected to an annealing at 900°C for 4 hours, which shows that the impact on the composition of the invention increasing the temperature from 900°C to 1000°C a significant sintering of oxide particles on the media does not occur.

According to preferred variants of implementation of the present invention the particle size of the oxide on the carrier can be even lower than the sizes listed above. Thus, the compositions are subjected to calcination for 4 hours at 900°C, the said amount may be not more than 4 nm, if the oxide on the carrier obtained on the basis of zirconium oxide, possibly doped, and not more than 7 nm, if the oxide on the carrier based on titanium oxide or a mixed oxide of zirconium and titanium. The minimum particle size are not critical and can be very low. Solely as an example, you can specify that the size of the particles may be at least 2 nm, more preferably at least 3 nm, if the oxide on the carrier obtained on the basis of zirconium oxide, possibly doped, and at least 3 nm, more preferably at least 4 nm, if the oxide on the carrier based on titanium oxide or a mixed oxide of zirconium and titanium. These minimum values are also given for the compositions subjected to calcination at 900°C for 4 hours./p>

For songs that have been subjected to calcination for 4 hours at 1000°C, the said amount may be not more than 6 nm, if the oxide on the carrier obtained on the basis of zirconium oxide, possibly doped, not more than 15 nm, if the oxide on the carrier based on titanium oxide, and not more than 8 nm, if the oxide on the carrier obtained on the basis of a mixed oxide of zirconium and titanium. Purely as an example, you can specify that for compositions subjected to calcination for 4 hours at 1000°C, the particle size may be at least 2 nm, more preferably at least 3 nm, if the oxide on the carrier obtained on the basis of zirconium oxide, possibly doped with at least 6 nm, more preferably at least 7 nm, if the oxide on the carrier based on titanium oxide, and at least 5 nm, more preferably at least 6 nm, if the oxide on the carrier obtained in the basis of a mixed oxide of zirconium and titanium.

The last value can be applied to the compositions, also previously subjected to an annealing at 900°C for 4 hours.

The content of the oxide on the carrier in the composition according to the invention is usually not more than 50 wt.% on the whole composition (oxide on the media and the media). In particular, it can be no more than 30%.

The minimum content of the oxide on the media is so important, to the torus skilled in the art will know, since it is possible to achieve a sufficient catalytic activity and is determined depending on the desired performance of the composition. Just as an example, we can say that the mentioned minimum value is usually at least 3 wt.%, more preferably at least 4 wt.%.

The oxide content in the media, in particular, may lie in the range from 10% to 50%, more preferably from 10% to 30%.

Media in compositions represents the media on the basis of silicon oxide.

Taking into account the application of the compositions according to the invention in applied catalysis a silicon oxide, suitable for use in the field, preferably silicon oxide, having a high and stable, i.e. keeping a high enough value even after exposure to high temperature specific surface. For example, it is possible to use silica having a specific surface area equal to at least 100 m²/g, preferably at least 150 m²/year

Such silicon oxide may be a precipitated or pyrogenic silica. The silicon oxide can be stabilized stabilizing element, for example, aluminum.

As examples of oxides of silicon, suitable for use in the present invention, it is possible to result such is, as described in WO 2005/061384 and WO 99/49850.

Finally, it should be stated that the composition of the invention can have a high specific surface area by BET, is able to make after firing at 900°C for 4 hours, at least 80 m²/g, more preferably at least 120 m²/g, even more preferably at least 150 m²/g After calcination for 4 hours at 1000°C. such compositions may have a specific surface area equal to at least 50 m²/g, more preferably at least 80 m²/g, even more preferably at least 100 m²/year

According to a preferred variant implementation as a carrier used silicon oxides, previously subjected to firing at a temperature lying in the range from 600°C or 650°C to 900°C and having a value loss on ignition (SPT)lying in the range from 2% to 15%, more preferably from 2 to 10% (measured until reaching constant weight).

The composition of the invention can be prepared in various ways, which are described next.

A. the First method of preparation of the compositions according to the invention

The first method includes the following steps:

- cast colloidal dispersions of compounds of zirconium and/or titanium, and may compound of the element M in contact with the suspension wear the El;

- spray drying thus obtained mixture;

- firing the dried product obtained in this way.

Thus, the first step of this method consists in obtaining a mixture of a colloidal dispersion of zirconium compounds, colloidal dispersion of titanium compounds or colloidal dispersion containing a compound of zirconium, and a compound of titanium, depending on the nature of the oxide on the carrier in the composition that you want to cook. In the case of the preparation of compositions in which the oxide on the carrier is a mixture of zirconium oxide and at least one oxide of another element M, the mixture also contains a colloidal dispersion of the oxide of this element. You can also use one of the colloidal dispersion, the basis of colloids in which is a mixed oxide of zirconium and of an element M of Course, this description applies to the case where the oxide on the carrier contains several elements of M; in this case, it is clear that this can be applied several dispersions of the various elements of M, or perhaps only one colloidal dispersion containing all of the elements of M. For brevity, in the remainder of this description reference will be made to only one dispersion of one element M, however, the present description should be understood as applicable to the above case.

The mixture obtained from the above-mentioned dispersion and suspension media. In particular, you can use colloidal dispersion of silicon oxide. Suspension in General is an aqueous suspension.

The mixture is produced in the aqueous phase, usually water, for example, distilled or permuteran water.

The second step of the method is the step of drying.

Drying is carried out by sputtering.

Under spray drying understand the drying by spraying a mixture of hot at the osphere (spray-drying). Spraying can be carried out in any well-known type of spray, for example, spray shower head type sprayer or otherwise. It is also possible to implement a so-called turbine nozzles. Information about the various methods of spraying, suitable for use in the present method, it is possible, in particular, be found in the seminal work of masters, entitled "Spray drying" (K. Masters, Spray-drying, 2nd ed., 1976, George Godwin, London).

The temperature at the outlet of the atomizer may lie in the range of, for example, from 80°C to 150°C.

The last step of the method is the step of firing.

Such firing provides the possibility of increasing the crystallinity of the product on the media; the firing method can also be adjusted and/or selected depending on the temperature further application, intended for the composition according to the invention, while taking into account the fact that the specific surface of the product is lower the higher the applied temperature firing. Such firing is usually carried out in air, but, of course, does not rule out the firing, for example, in an inert gas or in a controlled (oxidizing or reducing) atmosphere.

In practice, the firing temperature is usually limited by the range of values lying between 500°C and 800°C, preferably between 600°C and 700°C. the Time of firing is picked in a known manner; it may change, for example, from 30 minutes to 4 hours, but usually the lower, the higher the temperature.

B. the Second method of preparation of the compositions according to the invention

The composition of the invention can also be prepared by the second method described below.

This method contains the following steps:

- obtaining a liquid mixture containing a salt of zirconium or titanium, and possibly the element M and the suspension media;

- heating the thus obtained mixture to a temperature equal to at least 100°C;

the extract thus obtained precipitate;

- firing is referred to sludge.

In the first stage, as in the previous method, apply the suspension media, but it is mixed with the salt of zirconium and/or titanium salt and in the case of compositions in which the oxide on the carrier obtained on the basis of zirconium oxide and an oxide of another element M, with a salt of the element M, the Mixing is carried out in aqueous phase, usually in water. The original suspension of silicon oxide may be acidified.

Salt preferably represent inorganic salts and can be selected, in particular, among nitrates, sulfates, acetates and chlorides.

Thus, in the examples, in particular, to mention sulfate Zirconia, nitrate Zirconia and chloride Zirconia. You can also use oxychloride or oxysulfate titanium.

Following this the method is a step of heating the thus obtained liquid mixture.

The temperature to which the heated liquid mixture is at least 100°C., more preferably at least 130°C. It can also be in the range from 100°C. to 150°C. the heating Operation can be carried out by placing the liquid mixture in a closed shell (closed-type reactor of the autoclave). As an illustration, you can specify that in the above temperature conditions in the aquatic environment pressure in the closed reactor can vary over a range of values from more than 1 bar (105 PA) and 165 bar (1,65 .107 PA), preferably between 5 bar (5.105 PA) and 165 bar (1,65 .107 PA). At temperatures close to 100°C, it is also possible implementation of heating in an open reactor.

Heating can be carried out either in air or in an atmosphere of inert gas, preferably nitrogen.

Heating time may vary within wide limits, components, for example, from 1 to 48 hours, preferably from 2 to 24 hours. The temperature rise execute with speed, which is not critical; thus, a given reaction temperature can be achieved by heating the liquid mixture, for example, during the time of 30 minutes to 4 hours, and mentioned only that values are given only as an example.

After the step of heating the extracted solid residue, which may be separated from its containing environment with the use of any classic what about the method of separation of solid and liquid phases, including, for example, filtration, decantation, drying or centrifuging.

The extracted product can then be subjected to the procedures of washing, which in this case is carried out by means of water or perhaps a basic solution such as ammonia solution or an acidic solution, such as, for example, nitric acid.

In accordance with the private embodiment of the present invention the method includes the step of aging.

Mentioned aging usually carried out in a suspension obtained after repeated cultivation of sediment in the water, particularly after washing. Aging is carried out by re-heating of the suspension. The temperature to which heat the suspension is at least 40°C., more preferably at least 60°C., even more preferably at least 100°C. Typically, this temperature is not more than 200°C., more preferably not more than 150°C. Environment support at a constant temperature for a period of time, usually at least 30 minutes, more preferably at least 1 hour. Aging may be carried out at atmospheric pressure or, possibly, at higher pressure.

The last step of annealing the second method can be carried out in the same way as in the first method, therefore, discussed above, regarding the firing which is applicable to this case.

C. a Third method of preparation of the compositions according to the invention

The composition of the invention can also be prepared by the third method, described next. This method contains the following steps:

- obtaining a liquid mixture containing a suspension of the carrier and at least one salt of zirconium or titanium, and may element M;

- bringing the just-mentioned mixture in contact with the base with the purpose of obtaining a precipitate;

- removing the precipitate, thus obtained;

- firing above the sediment.

The first step of the third method is similar to the first stage of the second method, so the above on this issue is applicable to this case.

The second step consists in obtaining a precipitate from the reaction mixture obtained in the previous step, to the base.

As a basis you can use products like, for example, hydroxides, carbonates or basic carbonates. Mention can be made of hydroxides of alkaline or alkaline earth metals, secondary, tertiary, or Quaternary amines. However, amines and ammonia may be preferred for the reason that they reduce the risk of contamination of the cations of the alkaline or alkaline earth metals. You can also mention urea.

Bringing into contact, or the contact may be carried out in a liquid medium in any order./p>

Making contact with the ground is a consequence of the sediment suspended in the liquid reaction medium.

The addition of a base, in particular, is carried out until reaching the pH of the reaction medium, is equal to at least 7.

According to one of embodiments of this method, it can contain additional step consisting in treating the suspension obtained in the previous step, by aging. Aging is carried out by heating the suspension to a temperature component of at least 60°C., more preferably at least 80°C. This temperature is usually not more than 200°C., more preferably not more than 150°C. Environment support at a constant temperature for a period of time, usually at least 30 minutes, more preferably at least 1 hour. Aging may be carried out at atmospheric pressure or, possibly, at higher pressure.

The extraction and burning of sludge spend ways, similar to the one described above, in particular, for the second method.

The composition of the invention, such as those described above, or the like obtained by the methods described above have the form of powders, however, they may be molded in order to give them the form of granules, beads, cylinders or honeycombs of various sizes.

The composition of the invention can the be used as catalysts. Therefore, the present invention also relates to catalytic systems containing compositions according to the invention. Such systems contain coating (primer, wash coat) with catalytic properties derived from such compositions, and a binder is applied onto a substrate type, for example, metal or ceramic monolithic. The coating is obtained by mixing the composition with a binder so as to form a suspension, which can then be applied to the substrate.

Such catalytic systems, in particular, the composition according to the invention can find a lot of different ways. They are particularly well adapted to the conditions and, therefore, are applicable for the catalysis of various reactions, including, for example, dehydration, hydrocortisone, gidrogenizirovanii, desulfuromonas, hydrodesulfurised, dehydrohalogenation, reforming, steam reforming, cracking, hydrocracking, hydrogenation, dehydrogenation, isomerization, disproportionation, oxychlorination process, dehydrocyclization hydrocarbons or other organic compounds, oxidation reactions and/or recovery, the Claus reaction, treatment of exhaust gases of internal combustion engines, including afterburning of exhaust gases, in particular, in a three-component catalyst is, demetilirovania, mahanirvana, shift-conversion, catalytic oxidation of soot generated by internal combustion engines, including diesel or petrol engines operating at low loads. Finally, the catalytic system and the composition of the invention can find application as catalysts for selective reduction of NOx by reduction reaction of NOx in any reductant hydrocarbon nature, as well as ammonia or urea, and in the latter case, as catalysts for hydrolysis or decomposition of urea to ammonia (method SCR).

In the above-mentioned applications in catalysis compositions according to the invention can be used in combination with precious metals, and transition metals in the form of oxides, sulfides or other form, and thus play the role of the media data for metals. The nature of these metals and methods of their introduction in the compositions carriers are well known to the person skilled in the art. For example, the metals may include gold, silver, platinum, rhodium, palladium or iridium, molybdenum, tungsten, Nickel, cobalt, manganese or vanadium; they can be used separately or in combination with each other and, in particular, can be incorporated into the compositions by impregnation.

When processing the exhaust gases described is use system known methods installed in the exhaust of motor vehicles.

Further, the present invention is illustrated in the examples.

Example 1

This example relates to the preparation of the first method according to the invention the composition of the invention on the basis of zirconium oxide dispersed on a carrier of silica, when the respective mass fractions of oxides, equal to 30% and 70%.

Pre-made preparation of colloidal solution of ZrO₂. To this concentrated solution of ZrO(NO₃)₂diluted permuteran water to obtain 600 ml of a solution of ZrO(NO₃)₂concentration equal to 80 g/l in terms of ZrO₂pH is equal to 2. Instantly added a 28% solution of NH₃so that the final pH reached 10, and observed the formation of sludge. The precipitate was filtered, then washed with 6 l of permuteran water. The filter cake is re-suspended in permuteran water (pH 7.5) and acidified by addition of 68% nitric acid solution so that the suspension concentration was 10 wt.% in terms of ZrO₂. After keeping under stirring for one night got a transparent view of a colloidal solution, the particle size of which is measured using quasi-elastic light scattering, was 4 nm.

To 430 g of this colloidal solution under stirring was added aminocaproic acid is the fact that to increase pH and to stabilize it with the value of 4.5 (98% 6-aminocaproic acid obtained from Aldrich), and then with stirring, was added 100 g of a powder of silicon oxide (Rhoda Siloa®) (specific surface area of 170 m²/g SPT 15%). Thus obtained suspension was maintained for 30 minutes under stirring, and then sprayed by setting Büchi^®at 110°C. (outlet temperature 110°C, inlet temperature 220°C) and flow rate of 1 l/h of the Obtained powder was subjected to calcination in air at 700°C for 4 hours.

Example 2

This example relates to the production of the third method according to the invention, a composition based on zirconium oxide on a carrier of silica at the respective mass fractions of oxides, equal to 10% and 90%.

Used silicon oxide represented Tixosil 68^®dry residue which at 900°C was 90% (SPT 10%), and specific surface area of 160 m²/year Source of zirconium served a solution of ZrO(NO₃)₂dry residue which at 900°C was 19.1 per cent. Dilute ammonia solution with a concentration of 10% was obtained by addition of two volumes of water to one volume of 28% NH₃.

In the reactor received seed by introducing 59,80 g of silicon oxide (i.e. 54 g SiO₂)diluted 771 ml permuteran water (70 g/l in terms of SiO₂), then added 68% HNO₃received the eat dispersion, pH of which was equal to 2. The seed crystal was added 31,41 g of a solution of ZrO(NO₃)₂(i.e. 6 g in terms of ZrO₂)diluted permuteran with water to volume 86 ml (70 g/l in terms of ZrO₂), then at a rate of 10 ml/min was added to the ammonia solution to achieve pH 9 (weight added ammonia solution was 32 g).

The resulting system was transferred into the autoclave and stirring was kept at a temperature of 150°C for 2 hours.

The cooled mixture was then separated by filtration and washed at room temperature for a volume of water equal to the volume of the solution before filtration. After that, the filter cake was subjected to calcination in air at 700°C for 4 hours.

Example 3

This example relates to the production of the third method according to the invention, a composition based on zirconium oxide on a carrier of silica at the respective mass fractions of oxides, equal to 30% and 70%.

Used the same silicon oxide, a source of zirconium and ammonia solution as in example 2.

In the reactor received seed by introducing 46,51 g of silicon oxide (i.e. 42 g SiO₂), diluted with 600 ml permuteran water (70 g/l in terms of SiO₂), then added 68% HNO₃obtaining the dispersion, the pH of which was equal to 2. The seed crystal was added 94,24 g of a solution of ZrO(NO₃)₂(i.e. 18 g in terms of n is ZrO ₂)diluted permuteran with water to volume 257 ml (70 g/l in terms of ZrO₂), then at a rate of 10 ml/min was added to the ammonia solution to achieve pH 9 (weight added ammonia solution was 73 g).

Then in the same manner as in example 2, was carried out by autoclaving, washing and roasting.

Example 4

This example relates to the production by the third method according to the invention is a composition based on titanium oxide on a carrier of silica at the respective mass fractions of oxides, equal to 10% and 90%.

200 g of powdered silicon oxide Tixosil 68^®was dispersible in 570 ml of water to which was added HNO₃to achieve a pH of 0.5. To the resulting medium was then added to 26.8 g TiOCl₂(21 wt.% in terms of TiO₂). After this was added 10% NH₄OH to bring the pH to 7.

Then in the same manner as in example 2, was carried out by autoclaving, washing and roasting.

Example 5

This example relates to the production by the third method according to the invention is a composition based on titanium oxide on a carrier of silica at the respective mass fractions of oxides, equal to 30% and 70%.

155,6 g of powdered silicon oxide from example 2 was dispersible in 470 ml of water to which was added 13.3 g of concentrated HNO₃to achieve a pH of 0.5. To the resulting environment, then d is balali 80,37 g TiOCl ₂dissolved in 204,6 ml of water. After this was added 10% NH₄OH to bring the pH to 7.

Then in the same manner as in example 2, was carried out by autoclaving, washing and roasting.

Example 6

This example relates to the production of the third method according to the invention, a composition based on oxides of titanium and zirconium on the media of silicon oxide at the respective mass fractions of oxides, equal to 30% for ZrTiO₄and 70% for SiO₂.

155,6 g of powdered silicon oxide from example 2 was dispersible in 470 ml of water to which was added 10 g of concentrated HNO₃to achieve a pH of 0.5. To the resulting medium was then added 30,9 g TiOCl₂and 39,24 g ZrOCl₂dissolved in 208 ml of water. After this was added 10% NH₄OH to bring the pH to 7.

Then in the same manner as in example 2, was carried out by autoclaving, washing and calcination. RD-analysis allowed us to establish the presence of a single phase ZrTiO₄.

The following examples are comparative examples in which applied the known impregnation method.

Comparative example 7

This example relates to the production of compositions based on titanium oxide on a carrier of silica at the respective mass fractions of oxides, equal to 10% and 90%.

Composition comprising 90% of SiO₂and 10% of TiO₂got dry what robidou 16,09 g of silica from example 2 only 6.64 g of the solution TiOCl ₂c concentration of 25.1 wt.%, pre-diluted with 23.5 ml of N₂O.

Then the powder was subjected to calcination in air at 700°C for 4 hours. Way RD was confirmed by the presence of a single phase of anatase between 700 and 900°C.

Comparative example 8

This example relates to the production of compositions based on titanium oxide on a carrier of silica at the respective mass fractions of oxides, equal to 30% and 70%.

A composition containing 70% SiO₂and 30% of TiO₂was obtained by dry impregnation 12,88 g of silica from example 2 20,49 g of the solution TiOCl₂c concentration of 25.1 wt.%, pre-diluted with 9 ml of N₂O.

Then the powder was subjected to calcination in air at 700°C for 4 hours.

Comparative example 9

This example relates to the production of compositions based on titanium oxide on a carrier of silica at the respective mass fractions of oxides, equal to 30% and 70%.

A composition containing 70% SiO₂and 30% of TiO₂was obtained by dry impregnation of 22.5 g of silica from example 2 15,45 g of the solution TiOCl₂c concentration of 25.1 wt.%, pre-diluted to 14.3 ml of N₂O.

Then the powder was subjected to calcination in air at 700°C for 4 hours. Way RD was confirmed by the presence of a single phase ZrTiO₄between 700 and 1000°C.

In the following next table p is Evegeny characteristics of the compositions, obtained in the various examples, i.e. their specific surface area by BET and the size of the oxide particles on the media at different temperatures of firing.

It is seen that the composition of the invention include the oxides on the carrier, the particle size of which is considerably less compared to the oxides in the compositions obtained by the known impregnation method.

1. Composition containing at least one oxide on the carrier obtained on the basis of zirconium oxide, titanium oxide or a mixed oxide of zirconium and titanium supported on a carrier on the basis of silicon oxide, characterized in that after firing at 900°C for 4 h the oxide on the carrier is in the form of particles deposited on said media, the size of which is:
not more than 5 nm, if the oxide on the carrier obtained on the basis of the oxide circa the Oia;
not more than 10 nm, if the oxide on the carrier obtained on the basis of titanium oxide;
not more than 8 nm, if the oxide on the carrier obtained on the basis of a mixed oxide of zirconium and titanium.

2. Composition containing at least one oxide on the carrier obtained on the basis of zirconium oxide, titanium oxide or a mixed oxide of zirconium and titanium supported on a carrier on the basis of silicon oxide, characterized in that after firing at 1000°C for 4 h the oxide on the carrier is in the form of particles deposited on said media, the size of which is:
not more than 7 nm, if the oxide on the carrier obtained on the basis of zirconium oxide;
not more than 19 nm, if the oxide on the carrier obtained on the basis of titanium oxide;
not more than 10 nm, if the oxide on the carrier obtained on the basis of a mixed oxide of zirconium and titanium.

3. The composition according to claim 1 or 2, characterized in that the proportion of oxide on the carrier it is not more than 50 wt.%, more preferably not more than 30 wt.%.

4. Composition according to any one of the preceding paragraphs, characterized in that the oxide on the carrier obtained on the basis of zirconium oxide and at least one oxide of another element M selected from among praseodymium, lanthanum, neodymium and yttrium.

5. The composition according to claim 1, characterized in that the oxide on the carrier is in the form of particles, the size of which is:
not more than 4 nm, if the oxide on the carrier obtained n the basis of zirconium oxide;
not more than 7 nm, if the oxide on the carrier based on titanium oxide or a mixed oxide of zirconium and titanium.

6. The composition according to claim 2, characterized in that the oxide on the carrier is in the form of particles, the size of which is:
not more than 6 nm, if the oxide on the carrier obtained on the basis of zirconium oxide;
not more than 15 nm, if the oxide on the carrier obtained on the basis of titanium oxide;
not more than 8 nm, if the oxide on the carrier obtained on the basis of a mixed oxide of zirconium and titanium.

7. A method of obtaining a composition according to any one of the preceding paragraphs, characterized in that it comprises the following stages:
- cast colloidal dispersions of compounds of zirconium and/or titanium, and may compound of the element M in contact with the suspension media;
- spray drying thus obtained mixture;
- firing the dried product obtained in this way.

8. A method of obtaining a composition according to any one of claims 1 to 6, characterized in that it comprises the following stages:
- obtaining a liquid mixture containing at least one salt of zirconium or titanium, and possibly the element M and the suspension media;
- heating the thus obtained mixture to a temperature equal to at least 100°C;
the extract thus obtained precipitate;
- firing is referred to sludge.

9. A method of obtaining a composition according to any one of claims 1 to 6, characterized in that it contains what it the following stages:
- obtaining a liquid mixture containing a suspension of the carrier and at least one salt of zirconium or titanium, and may element M;
- bringing the just-mentioned mixture in contact with the base with the purpose of obtaining a precipitate;
- removing the precipitate obtained in this way;
- firing above the sediment.

10. The method according to claim 9, characterized in that the precipitate obtained after bringing it in contact with the ground, is subjected to aging.

11. The catalytic system, characterized in that it contains a composition according to any one of claims 1 to 6.