Composition based on cerium, niobium and, possibly, zirconium oxides and its application in catalysis

FIELD: chemistry.

SUBSTANCE: invention relates to catalytic purification of exhaust gases of internal combustion engines. Claimed is composition for purification of exhaust gases of internal combustion engines based on cerium oxide, containing niobium oxide, with the following weight contents: niobium oxide from 2 to 20%, the remaining part - cerium oxide. Also claimed is composition with the following weight contents: cerium oxide at least 65%, niobium oxide from 2 to 12%, zirconium oxide to 48%. After calcinations for 4 hours at 800°C compositions have acidity at least 6·10-2, with said acidity being expressed in ml of ammonia per m2 of composition, with the surface, expressed in m2, used for determination of acidity, representing specific surface after calcinations for 4 hours at 800°C and specific surface at least 15 m2/g, and after calcinations for 4 hours at 1000°C it has specific surface at least 2 m2/g, in particular at least 3 m2/g. Invention relates to catalyst, which contains said compositions, to methods of oxidising CO and hydrocarbons, N2O, decomposition, for HOx and CO2 adsorption. Said compositions and catalyst are applied in reaction of gas with water, reaction of conversion with water steam, isomeration reaction, reaction of catalytic cracking and as triple action catalyst.

EFFECT: compositions possess satisfactory reducing ability in combination with good acidity, specific surface of which remains suitable for application in catalysis.

16 cl, 1 tbl, 14 ex

 

The present invention relates to a composition based on oxides of cerium, niobium, and possibly zirconium and its application in catalysis, in particular for purification of exhaust gases.

Currently for purification of exhaust gases of internal combustion engines (automobile afterburning catalysis) use catalysts, called multifunctional. Under polyfunctional mean catalysts capable of carrying out not only oxidation, in particular of carbon monoxide and hydrocarbons present in exhaust gases, but equally the restoration, in particular of nitrogen oxides also present in these gases (catalysts "triple action"). Zirconium oxide and cerium oxide are presented today as the two components are especially important and interesting for this type of catalysts.

To be effective, these catalysts must possess, in particular, good resilience. Under reducing ability here and in the rest of the description mean the ability of the catalyst to recover in a reducing atmosphere and re-oxidized in an oxidizing atmosphere. This regenerative ability can be measured, for example, the consumption of hydrogen in a predetermined temperature region. In the case of compositions, such compositions according to the invention, it is obliged to cerium as cerium has the ability to recover or be oxidized.

In addition, these products must have sufficient acidity, providing, for example, good resistance to sulfation.

Finally, to be effective, these catalysts must have a specific surface area, which remains sufficient at high temperatures.

The task of the invention is to provide a composition which has satisfactory resilience combined with good acidity and specific surface area which is suitable for use in catalysis.

To this end, the composition according to the invention is a composition based on cerium oxide, and it is characterized in that it contains an oxide of niobium with the following mass concentrations:

- niobium oxide of 2 to 20%

- the rest of the cerium oxide.

Other characteristics, details and advantages of the invention will appear more fully upon reading the description which follows, as well as various specific but non-restrictive examples are intended to illustrate.

This description under rare earths mean the elements of the group formed by yttrium and the elements of the periodic system with atomic numbers 57 to 71 inclusive.

Under a mean specific surface the specific surface area BET (B. E. T.), determined by nitrogen adsorption according to the standard�mouth ASTM D 3663-78, based on the method of Brunauer-Emett-teller (BRUNAUER-EMMETT-TELLER described in the periodical “The Journal of the American Society, 60, 309 (1938)”.

The values of specific surface, which are for temperature and duration, unless indicated to the contrary, comply with prokalivaniem on the air on the plateau at this temperature and within the specified time period.

Calcination mentioned in the description, are a calcination in air, unless indicated to the contrary. The time of calcination, which is specified for a given temperature corresponds to the duration of the plateau at this temperature.

Contents or structures are given by weight and based on the oxide (in particular, CeO2, Ln2O3while Ln denotes a trivalent rare earth element Pr6O11in the particular case of praseodymium, Nb2O5in the case of niobium), unless indicated to the contrary.

Clarify also for the continuation of the description, unless indicated to the contrary, within the ranges of values given, the extreme values are included.

The composition according to the invention is distinguished primarily by the nature and content of its components. Thus, according to the first method of implementation, the composition is a composition based on cerium and niobium, and these elements are present in sost�ve usually in the form of oxides. These elements, moreover, are present in the specific contents of which have been given above.

Cerium oxide composition may be "stable", "stable" here imply the stabilization of the specific surface using at least one rare earth element other than cerium, in the form of oxide. This rare earth element can represent, in particular, yttrium, neodymium, lanthanum or praseodymium. The content of the stabilizing oxide of rare earth element is usually at most 20%, preferably when the rare earth element is lanthanum, in particular at most 15%, preferably at most 10 wt%. The content of the stabilizing oxide of rare earth element is not critical, but usually it is at least 1%, particularly at least 2%. This content is expressed in the calculation of the oxide of rare earth element with respect to the weight of the complex oxide of cerium-oxide stabilizing rare earth element.

Cerium oxide may also be stabilized, stabilization is always from the point of view of the specific surface, the oxide selected from among silicon dioxide, aluminum oxide and titanium oxide. The content of this stabilizing oxide may be at most 10%, in particular at most 5%. The minimum content of the composition may�ive at least 1%. This content is expressed in the calculation of the stabilizing oxide relative to the weight of the complex oxide of cerium-stabilizing oxide. According to another embodiment of the invention, the composition according to the invention contains three components, also in the form of oxides, which are cerium, niobium and zirconium.

The corresponding concentrations of these elements in this case are the following:

- cerium oxide at least 50%;

- niobium oxide of 2 to 20%;

- zirconium oxide to 48%.

A minimum content of zirconium oxide in the case of this second embodiment of the invention is preferably at least 10%, in particular at least 15%. The maximum content of zirconium oxide can be, in particular at most 40%, even more particularly at most 30%.

According to a third embodiment of the invention, the composition according to the invention contains, in addition, at least one oxide of an element M that is selected in the group comprising tungsten, molybdenum, iron, copper, silicon, aluminum, manganese, titanium, vanadium and rare earth elements other than cerium, with the following mass concentrations:

- cerium oxide at least 50%;

- niobium oxide of 2 to 20%;

- oxide of the element M to 20%;

- the rest is zirconium oxide.

The element M may, to a pri�STI, to play the role of stabilizer of the surface mixed oxide of cerium and zirconium or improve the regenerative ability of the composition. In continuation of the description it should be understood that, if in order to simplify mention only one element M, it is understood that the invention is applicable in the case where the compositions contain several elements M.

The maximum content of oxide of the element M in the case of rare earth elements and tungsten can be, in particular, not more than 15% and even more particularly not more than 10 wt%. oxide of element M (a rare earth element or tungsten). The minimum content is at least 1%, particularly at least 2%, and the above content is expressed in relation to the totality of the cerium oxide - zirconium oxide - oxide of the element M.

In the case when M is neither a rare earth element, or tungsten, the content of oxide of the element M can be, in particular, not more than 10%, more particularly not more than 5%. The minimum content may be at least 1%. This content is expressed in the calculation of the oxide of the element M relative to the complex oxide of cerium-zirconium oxide and an oxide of element M.

In the case of rare earth elements, the element M can represent, in particular, yttrium, lanthanum, praseodymium and neodymium.

For different ways of implementation described above, the content of hydroxy�and niobium may be, in particular, in the range from 3% to 15% and even more specifically from 4% to 10%.

In the case of compositions according to the second or third ways, and according to an advantageous embodiment, the content of cerium may be, at least 65%, particularly at least 70%, even more specifically at least 75%, and the content of niobium is in the range from 2 to 12%, in particular from 2 to 10%. The composition according to this embodiment has a high acidity and reducing capacity.

Meanwhile, for these different ways of implementation of the niobium content can also be, in particular, less than 10% and, for example, be in the range from the minimum value, which may be 2% or 4%, and the maximum value is strictly less 10%, for example, not more than 9%, in particular not more than 8%, in particular not more than 7%. This niobium content is expressed in weight of niobium oxide relative to the weight of the aggregate composition. The magnitude of the contents of niobium that will be given, in particular the magnitude strictly less than 10%, applicable to the advantageous embodiment according to the second or the third method, which was described before.

Finally, the compositions according to the invention have a relatively stable specific surface area, that is large enough at high temperature to ensure that they could be used in the field of catalysis.

So, typically, the compositions according to the first method of�I have a specific surface after calcination for 4 hours at 800°C, which is at least 15 m2/g, in particular at least 20 m2/g, more specifically at least 30 m2/g For the compositions according to the second and third ways of implementing this surface, in the same conditions, is usually at least 20 m2/g, in particular at least 30 m2/year For all three methods the compositions according to the invention can have a surface, changing up to 55 m2/g, approximately always the same calcination conditions.

The compositions according to the invention in the case where they contain niobium in amounts of at least 10%, and according to the advantageous method of implementation may have a specific surface after calcination for 4 hours at 800°C, which is at least 35 m2/g, in particular at least 40 m2/g.

Meanwhile, for the three methods, the compositions according to the invention can have a specific surface after calcination for 4 hours at 900°C, which is at least 10 m2/g, in particular at least 15 m2/G. In the same calcination conditions they may have specific surface, reaching up to 30 m2/g, approximately.

The compositions according to the invention, for all three methods, can have a specific surface after calcination for 4 hours p�and 1000°C, at least 2 m2/g, in particular at least 3 m2/g and still more specifically at least 4 m2/G. In the same calcination conditions they may have the surface, reaching up to 10 m2/g, approximately.

The compositions according to the invention have high acidity, which can be measured by TPD (TPD), which will be described later, and which is at least 5.10-2in particular, at least, 6.10-2even more specifically at least about 6.4.10-2. This acidity can be, in particular, at least 7.10-2and this acidity expressed as ml of ammonia on m2product. The surface is taken here into account, is the amount, expressed in m2the specific surface of the product after calcination for 4 hours at 800°C. Can be obtained acidity of at least 9,5.10-2approximately.

The compositions according to the invention also have important restorative properties. These properties can be measured by measuring recovery at programmed temperature change (TPR), which will be described later. The compositions according to the invention are resilient, at least 15, in particular at least 20, even more concrete�, at least, 30. This regenerative ability is expressed in ml of hydrogen per gram of product. The magnitude of resilience are derived for the structures subjected to calcination at 800°C for 4 hours.

The compositions can be in the form of a solid solution of oxides of niobium, a stabilizing element, in the case of the first method of implementation, of zirconium and of the element M in the oxide of cerium. Method of x-ray diffraction see then in this case the presence of a homogeneous phase, corresponding to the cubic phase of ceria. This characteristic of the solid solution is usually applied to structures subjected to calcination for 4 hours at 800°C or for 4 hours at 900°C.

The invention also applies to a case in which compositions consist essentially of the oxides of these elements, cerium, niobium, and possibly zirconium and an element of M. the term "consists essentially of" mean that the composition contains only the oxides of these elements and that it does not contain the oxide of another functional element, that is able to have a positive effect on the regenerative capacity and/or acidity and/or stability of the composition. But the composition can contain elements such as impurities, capable, in particular, be derived from the method of its production, such as those used� starting materials or reactants.

The compositions according to the invention can be obtained by a known method of impregnation. So, a pre-obtained cerium oxide or a mixed oxide of cerium and zirconium impregnated with a solution containing a compound of niobium, such as oxalate or niobium oxalate and ammonium. In the case of obtaining a composition that contains, in addition, an oxide of element M, for impregnation using a solution which, besides the compounds of niobium contains a compound of the element M. the Element M may also be present in the initial cerium oxide impregnated.

In particular, using impregnation in the dry state. Impregnation in the dry state is added to impregnate the product volume of an aqueous solution of a sealing element, which equals the pore volume of the impregnated solids.

Cerium oxide or a mixed oxide of cerium and zirconium should have a specific surface characteristics that make it suitable for applications in catalysis. Thus, this surface must be stable, i.e. it must have a value sufficient for such applications, even at high temperatures.

Such oxides are well known. From oxides of cerium can be used, in particular, oxides described in patent applications EP 0153227, EP 0388567 and EP 0300852. From oxides of cerium, stable element, as rarely�emeline elements silicon, aluminum and iron, you can use the products described in EP 2160357, EP 547924, EP 588691 and EP 207857. From mixed oxides of cerium and zirconium, and possibly the element M, in particular, in the case when M is a rare earth element, may be mentioned as products that conform to the present invention, the mixed oxides described in patent applications EP 605274, EP 1991354, EP 1660405, EP 1603657, EP 0906244 and EP 0735984. For the application of the present invention could, if necessary, to refer to the totality of the descriptions of the patent applications mentioned above.

The compositions according to the invention can also be obtained from the second method, which will now be described below.

This method contains the following stages:

- (A1) mixing a suspension of hydroxide of niobium with a solution containing a cerium salt and, possibly, of zirconium and of the element M;

- (b1) thus obtained mixture is brought into contact with the connection of the main character, resulting in a precipitate;

- (C1) separating the precipitate from the reaction mixture and calcined.

In the first stage of this method using a suspension of hydroxide of niobium. This suspension can be obtained by introducing into the reaction of the salt of niobium, such as chloride, with a base like ammonium hydroxide, to obtain the precipitate of the hydroxide of niobium. This slurry can also be obtained by reaction of salts of niobium, cannibal potassium or sodium, with acid, such as nitric acid, to obtain a precipitate of the hydroxide of niobium.

This reaction can occur in a mixture of water and alcohol, such as ethanol. The thus obtained hydroxide was washed by any known method and then re-suspended in water in the presence of a dispersing agent like nitric acid.

The second stage (b1) of the method consists in mixing the slurry of niobium hydroxide with a solution of a cerium salt. This solution may contain, in addition, zirconium salt and also element M, in the case of obtaining a composition that contains, in addition, zirconium oxide or zirconium oxide of the element M. These salts can be selected from the nitrates, sulfates, acetates, chlorides, nitrate of cerium-ammonium.

As examples of zirconium salts can, therefore, be called sulfate of zirconium, zirconolite or circinelloides. Often use zirconolite.

When using salt of cerium (III), it is preferable to introduction of the salt solution of an oxidant, such as peroxide of hydrogen.

Various dissolved salts are present in stoichiometric concentrations necessary to obtain the desired final composition.

The mixture formed a slurry of niobium hydroxide and a solution of salts of other elements, is brought into contact with the connection of the main character.

As the base or connection DOS�main character, you can use the products of the hydroxide type. You can call the hydroxides of alkaline or alkaline earth metals. You can also use a secondary, tertiary or Quaternary amines. However, amines and ammonium hydroxide may be preferred to the extent that they reduce the risk of contamination of the alkali or alkaline earth cations. You can also mention urea. The connection of the main character may be used, in particular, in the form of a solution.

The reaction between said compound and the connection of the main character is carried out, preferably, continuously in the reactor. Thus, this reaction is carried out by continuously introducing the mixture and connection of the main character and also continuously removing the reaction product.

The precipitate, which is obtained, is isolated from the reaction mixture by any conventional method for separation of solids and liquids, such as, for example, filtration, decantation, drying or centrifuging. This precipitate can be washed, and then calcined at a temperature sufficient for the formation of oxides, such as at least 500°C.

The compositions according to the invention can be also obtained by the third method, which contains the following stages:

- (A2) in the first stage, in a liquid medium a mixture containing a compound of cerium and possibly a compound of zirconium and an element of M, to obtain compositions that contain OK�ID of zirconium or a zirconium oxide and an oxide of element M;

- (b2) is introduced into the contact of this mixture and connection of the main character, to thereby produce a slurry containing the precipitate;

- (C2) this slurry was mixed with a solution of salt of niobium;

- (d2) separating the solid from the liquid medium;

- (E2) specified calcined solid.

The cerium compound may be a compound of cerium (III) or cerium (IV). The compounds preferably are soluble compounds such as salts. What was said above for the salts of cerium, zirconium and an element of M, is also applicable here. This applies also to the nature of the connection of the main character. Various compounds of the starting mixture of the first stage are present in stoichiometric concentrations necessary to obtain the desired final composition.

Liquid medium of the first stage usually is water.

The initial mixture of the first stage may be indifferent to, received by or proceeding from compounds initially in the solid state, which will then be entered in the lower part of the tank with water, for example, or proceeding directly from solutions of these compounds, followed by mixing these solutions in any order.

The order of introduction of the reactants in the second stage (b2) can be arbitrary, and the connection of the main character may be introduced in mixture� or separately, or reagents can be introduced into the reactor simultaneously.

The addition may be carried out at once, in portions or continuously, and it is carried out preferably with stirring. This operation can be carried out at a temperature in the range from room temperature (18-25°C) to the boiling point of the reaction mixture, and the latter can reach 120°C, for example. Preferably, it is carried out at room temperature.

As in the case of the first method, it can be noted that, in particular in case of use of cerium (III), or add to the original mixture, or during insertion of the connection of the main character, an oxidizer, such as hydrogen peroxide. Until the end of the second stage (b2) of Appendix connect the main character can, if necessary, to support the reaction medium under stirring for some time, and it is for the purpose of completing the deposition.

At this stage of the method can also be maturing. It can be carried out directly on the reaction medium obtained after mixing with the connection of the main character, or on a suspension obtained after repeated areas of sediment in the water. The maturation is carried out by heating the environment. The temperature at which the heated medium is at least 40°C, in particular, p� least 60°C, and even more specifically at least 100°C. thus, the support environment at a constant temperature for a period of time which is usually at least 30 minutes, in particular at least 1 hour. Ripening can be carried out at atmospheric pressure or, if necessary, at higher pressure and at a temperature above 100°C, in particular in the range from 100°C to 150°C.

The next stage (S2) of the method consists in mixing the suspension resulting from the previous stage, with the salt solution of niobium. As the salt of niobium can be called niobium chloride, potassium niobate or sodium and, very particularly, from this point of niobium oxalate and niobium oxalate and ammonium.

This mixing is preferably carried out at room temperature.

The following method steps (d2) and (E2) are the allocation of the solids from the suspension obtained at the previous stage, perhaps washing this solid substance and then it is heated. These stages are developing identical to that described above for the second method.

In the case of compositions which contain the oxide of the element M, the third method may represent a variant in which the compound of the element M is not present in stage (A2). The compound of the element M is introduced in this case on stage (C2), or prior to mixing,or after mixing with a solution of niobium, or at the same time.

The third method may also be implemented according to another embodiment, in which after step (C2) in the environment resulting from this stage, the additive chosen from anionic surfactants, nonionic surfactants, polyethylene glycols, carboxylic acids and their salts and surfactants of the type of ethoxylates karboksimetilirovaniya fatty alcohols. Then stage (d2). It is also possible to carry out step (C2) and (d2), and then add the additive to the solid substance obtained as a result of the selection.

Regarding more precisely the nature of the additive, you can refer to the description of WO 2004/085039. As non-ionic surfactants may be mentioned in particular the products sold under the trademarks IGEPAL®, DOWANOL®, RHODAMOX®and ALKAMIDE®. As carboxylic acids, can be called, in particular, formic, acetic, propionic, butyric, isobutyric, valeric, Caproic, Caprylic, capric, lauric, myristic, palmitic acid, and their ammonium salts.

Finally, the compositions according to the invention on the basis of oxides of cerium, niobium and zirconium and possibly oxide of the element M can also be obtained by the fourth method, which is described below.

This method includes �next stage:

- (A3) in a liquid medium to prepare a mixture containing a zirconium compound and a cerium compound and possibly of the element M;

- (b3) warm this mixture at a temperature greater than 100°C;

- (c3) is brought to the reaction medium resulting from heating, to alkaline pH;

(c'3) may carry out the maturation of the reaction medium;

- (d3) mix this medium with a salt solution of niobium;

- (e3) distinguish the solid from the liquid medium;

- (f3) specified calcined solid.

The first stage of the method consists in the preparation in a liquid medium a mixture of compounds of zirconium and of cerium and possibly the element M Different compounds of the mixture are present in stoichiometric concentrations necessary to obtain the desired final composition.

The liquid medium is typically water.

The compounds are preferably soluble compounds. This can be, in particular, salts of zirconium, cerium and the element M, such as described above.

The mixture may be equivalent received or proceeding from compounds initially in the solid state, which will then be entered in the lower part of the tank with water, for example, or proceeding directly from solutions of these compounds, followed by mixing these solutions in any order.

Having thus factory�th mixture, then proceed according to the second stage (b3) this fourth method, heat.

The temperature at which carry out this heat treatment, also called thermohydrolysis, greater than 100°C. It can be in the range of from 100°C to the critical temperature of the reaction medium, in particular from 100 to 350°C, preferably from 100 to 200°C.

The heating operation may be carried out by introducing the liquid medium into a closed chamber (closed reactor of the type autoclave), the required pressure occurs in this case only by heating the reaction medium (independently developed pressure). Thus, for the above temperature conditions and the water environment can be updated, for illustration, that the pressure in the closed reactor can vary in the range from a value greater than 1 bar (105PA) to 165 bar (1.65 V.107PA), preferably between 5 bar (5.105PA) to 165 bar (1.65 V.107PA). Of course, equally possible to exert an external pressure that is added in this case to pressure resulting from the heating.

You can also be heated in an open reactor at temperatures close to 100°C.

The heating can be conducted or air, or an inert gas atmosphere, preferably nitrogen.

The duration of treatment is not critical and, sledovatel�till then, may vary within wide limits, for example from 1 to 48 hours, preferably from 2 to 24 hours. Also the rise of temperature is carried out at a speed that is not critical, and therefore can achieve a fixed reaction temperature by heating the medium, for example, from 30 minutes to 4 hours, and these values are given just for information.

At the end of this second stage, the reaction medium thus obtained, adjusted to alkaline pH. This operation is carried out by adding to the medium a base, such as, for example, the ammonium hydroxide solution.

Under alkaline pH the mean pH value greater than 7, preferably greater than 8.

Although this option is not preferred, can be introduced into the reaction mixture obtained by heating, in particular, at the time of adding the base, the element M, in particular, in the form that was described above.

At the end of the heating stage is recovered solid precipitate which can be isolated from its environment, as described before.

Product such as a dedicated, may be then subjected to leaching, which in this case is carried out with water or perhaps alkaline solution such as ammonium hydroxide solution. Rinsing may be effected by the return sludge in the form of a suspension in water and maintaining the suspension thus obtained, when the pace�the ture, which can reach up to 100°C. to remove residual water, the washed product may be dried, for example, in a drying Cabinet or a spray, and this at a temperature which can vary from 80 to 300°C, preferably from 100 to 200°C.

According to the private variant of the invention, the method includes maturing (stage C'3).

Ripening is carried out in the same conditions that the conditions that were described above for the third method.

Ripening can also be implemented on a suspension obtained after the return sludge in the water. You can bring the pH of this suspension to a value greater than 7, preferably greater than 8.

You can make a few dopravni. Thus, the precipitate obtained after the stage of ripening and possibly flushing can again translate into a slurry in water and then pull off another maturation thus obtained environment. This is different ripening is carried out in the same conditions that the conditions that were described for the first. Of course, this operation may be repeated several times.

The following stages of this fourth method (d3)-(f3), i.e. mixing with a solution of salt of niobium, separation of solid/liquid and calcination are carried out in the same manner that the respective second and third stages of the method. Thus, what would�about described above for these stages, applicable here.

The compositions according to the invention, such as described above, i.e. a composition based on oxides of cerium, niobium, and possibly zirconium and the element M are in the form of powders but they can, if necessary, be subjected to molding and can be in the form of granules, beads, cylinders or honeycombs of variable sizes.

These formulations can be used with any material, usually used in the field of catalyst preparation, i.e., in particular, a material selected from thermally inert materials. This material may be selected from among aluminum oxide, titanium oxide, cerium oxide, zirconium oxide, silica, spinels, zeolites, silicates, crystalline kriminaalmenetluses, crystalline aluminophosphates.

The compositions according to the invention, in any such case as described above, can also be used in catalytic systems containing coating (phosphating layer) with catalytic properties and based on these compositions with the material, the type of materials referred to above, wherein the coating is deposited on a substrate, e.g., a metal monolith, for example, zhelezohromovyh alloy (FerCralloy), or of ceramics, such as cordierite, silicon carbide, aluminum titanate or mullite.

This coating is obtained by mixing the composition with materialistakan way to form a slurry, which can then be deposited on a substrate.

In the case of applications in catalysis, in particular in the catalytic system described above, the compositions according to the invention can be applied in combination with precious metals, so perhaps they can act as substrates for these metals. The nature of these metals and methods of their introduction into the compositions is well known to specialists in this field. For example, the metals can be platinum, rhodium, palladium, silver, or iridium, in particular, they can be introduced into the compositions by impregnation.

Catalytic system and, in particular, the compositions according to the invention can find numerous applications.

These catalytic systems and, in particular, the compositions according to the invention can find numerous applications. So, they, in particular, are well adapted and can therefore be used in the catalysis of various reactions such as, for example, dehydration, hydrosulfurous, hydrodenitrification, desulfurization, hydrodesulfurized, the dehydrohalogenation was demonstrated, reforming, conversion with steam, cracking, hydrocracking, hydrogenation, dehydrogenation, isomerization, disproportionation, oxychlorination, dehydrocyclization of hydrocarbons or other organic compounds, oxidation and/or�of Stanovlenie, the Claus reaction, treatment of exhaust gases of internal combustion engines, demeterova, methanation, shift conversion, catalytic oxidation of soot emitted by internal combustion engines, both diesel or petrol engines operating with lean.

Systems and compositions according to the invention can be used as catalysts in the method of the reaction gas with water, a reforming reaction in the vapor phase isomerization reaction or the reaction of catalytic cracking. Finally, the catalytic systems and the compositions according to the invention can be used as traps NOx.

Catalytic systems and the compositions according to the invention can be in particular used in applications that follow below.

The first application relates to a method of gas purification, in which the use or composition according to the invention as a catalyst for the oxidation of CO and hydrocarbons contained in the gas.

According to the second application, systems and compositions according to the invention can also be used for the adsorption of NOxand CO2still, in the purification of gas.

The gas is purified in these two applications, may constitute a gas exiting the internal combustion engine (mobile or fixed).

According �other use the compositions according to the invention can be used in formulations of catalysts for the catalysis of triple action purification of exhaust gas of a gasoline engine, and the catalytic system according to the invention can be used for the implementation of the catalysis.

Another application concerns the use of systems and formulations according to the invention in the method of processing gas for the purpose of decomposition of N2O.

It is known that N2O is a significant number in gases emitted from some industrial installations. To avoid emissions of N2O, these gases are treated in such a way as to decompose the N2O for oxygen and nitrogen before throwing them into the atmosphere. Systems and compositions according to the invention can be used as catalysts for the reaction of decomposition, in particular, in the method of producing nitric acid or adipic acid.

Now we will provide an example.

EXAMPLE 1

This example is concerned with the obtaining of a composition according to the invention containing cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 63,0/27,0/10,0.

First obtain a suspension of hydroxide of niobium according to the following method.

In a reactor of 5 liter equipped with a stirrer and condenser, was administered to 1200 g of anhydrous ethanol. Then, when you shuffle�provided within 20 minutes was added to 295 g of powder of chloride of niobium (V). The mixture was left alone for 12 hours.

Into the reactor were introduced 50 g of deionized water and the medium was heated to reflux at 70°C for 1 hour. Was allowed to cool. This solution was designated A.

In a reactor with a volume of 6 liters equipped with a stirrer, were introduced 870 g of ammonium hydroxide solution (29,8% NH3). Under stirring within 15 minutes at the same time introduced the whole solution A and 2250 ml of deionized water. The suspension was extracted and washed several times with centrifugation. The product was centrifuged designated V.

In a reactor with a volume of 6 liters equipped with a stirrer, were injected 2.4 liter solution of 1 mol/l nitric acid. With stirring introduced into the reactor centrifuged product V. the Stirring was carried out for 12 hours. The pH value was 0.7. The concentration of Nb2O5was at 4.08%. This suspension was designated S.

Then prepared a solution of ammonium hydroxide (D, introducing 1040 g of concentrated ammonium hydroxide solution (29,8% NH3in 6690 g of deionized water.

Solution was prepared (E, mixing 4250 g of deionized water, 1640 g of solution of cerium nitrate (III) (30,32% SEO2), 1065 g of a solution of oxynitride zirconium (20,04% ZrO2), 195 g of hydrogen peroxide solution (50,30% for N2O2), 1935 suspension of 4.08% Nb2O5). This solution was left with stirring.

In the reactor amount� 4 liters with a stirrer, provided with a device for draining simultaneously added to the solution D and solution E with a capacity of 3.2 l/h. After entering setup mode, the precipitate was extracted into the barrel. The pH value remained stable and close to 9.

The suspension was filtered, the obtained solid product was washed and calcined at 800°C for 4 hours.

EXAMPLE 2

This example is concerned with the obtaining of a composition according to the invention containing cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 55,1/40,0/4,9.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same compounds, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 978 g

- deionized water: 6760 g

Prepared also a solution of E, as in example 1 and with the same compounds, but in the following proportions:

- deionized water: 5000 g

- a solution of cerium nitrate (III): 1440 g

- a solution of oxynitride Zirconia: 1580 g

- hydrogen peroxide: 172 g

- suspension: 950 g

Then operated as in example 1.

EXAMPLE 3

This example is concerned with the obtaining of a composition according to the invention containing cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 54,0/39,1/6,9.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same connection�s, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 1024 g

- deionized water: 6710 g

Prepared also a solution of E, as in example 1 and with the same compounds, but in the following proportions:

- deionized water: 4580 g

- a solution of cerium nitrate (III): 1440 g

- a solution of oxynitride Zirconia: 1580 g

- hydrogen peroxide: 172 g

- suspension: 1370 g

Then operated as in example 1.

EXAMPLE 4

This example is concerned with the obtaining of a composition according to the invention containing cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 77,9/19,5/2,6.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same compounds, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 966 g

- deionized water: 6670 g

Prepared also a solution of E, as in example 1 and with the same compounds, but in the following proportions:

- deionized water: 5620 g

- a solution of cerium nitrate (III): 2035

- a solution of oxynitride Zirconia: 770 g

- hydrogen peroxide solution: 242 g

- suspension: 505 g

Then operated as in example 1.

EXAMPLE 5

This example is concerned with the obtaining of a composition according to the invention containing cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass� ratios: 76,6/19,2/4,2.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same compounds, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 1002 g

- deionized water: g 6730

Prepared also a solution of E, as in example 1 and with the same compounds, but in the following proportions:

- deionized water: 5290 g

- a solution of cerium nitrate (III): 2035

- a solution of oxynitride Zirconia: 770 g

- hydrogen peroxide solution: 242 g

- suspension: 830 g

Then operated as in example 1.

EXAMPLE 6

This example is concerned with the obtaining of a composition according to the invention containing cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 74,2/18,6/7,2.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same compounds, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 1068 g

- deionized water: 6650 g

Prepared also a solution of E, as in example 1 and with the same compounds, but in the following proportions:

- deionized water: 4660 g

- a solution of cerium nitrate (III): 2035

- a solution of oxynitride Zirconia: 770 g

- hydrogen peroxide solution: 242 g

- suspension: 1470 g

Then operated as in example 1.

EXAMPLE 7

This example is concerned with the obtaining of a composition according to the invention, sod�rasego cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 72,1/18,0/9,9.

Preparing a solution of niobium oxalate (V) and ammonium dissolved when heated, 192 g of niobium oxalate (V) and ammonium in 300 g deionized water.

This solution was kept at 50°C. the Concentration of this solution was made up 14.2% of Nb2O5.

This solution was then injected on the powder mixed oxide of cerium and zirconium (mass composition of CeO2/ZrO280/20, specific surface area after calcination at 800°C for 4 hours - 59 m2/g) until saturation of the pore volume.

The impregnated powder was then calcined at 800°C (thermal pad 4 hours).

EXAMPLE 8

This example is concerned with the obtaining of a composition according to the invention containing cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 68,7/17,2/a 14.1.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same compounds, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 1148 g

- deionized water: 6570 g

Prepared also a solution of E, as in example 1 and with the same compounds, but in the following proportions:

- deionized water: 3400 g

- a solution of cerium nitrate (III): 1880 g

- a solution of oxynitride Zirconia: 710 g

- hydrogen peroxide: 224 g

- suspension: 2870 g

EXAMPLE 9

This example is concerned with the obtaining of a composition according to the invention, containing cerium oxide and niobium oxide, respectively, in the following mass ratios: 96,8/a 3.2.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same compounds, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 990 g

- deionized water: 6750 g

Prepared also a solution of E, as in example 1 and with the same connections, but without oxynitride zirconium and in the following proportions:

- deionized water: 5710 g

- a solution of cerium nitrate (III): 2540 g

- hydrogen peroxide: 298 g

- suspension: 628 g

Then operated as in example 1.

EXAMPLE 10

This example is concerned with the obtaining of a composition according to the invention, containing cerium oxide and niobium oxide, respectively, in the following mass ratios: 91,4/8,6.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same compounds, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 1110 g

- deionized water: 6610 g

Prepared also a solution of E, as in example 1 and with the same connections, but without oxynitride zirconium and in the following proportions:

- deionized water: 4570 g

- a solution of cerium nitrate (III): 2540 g

- hydrogen peroxide: 298 g

- susp�NSIA C: 1775 g

Then operated as in example 1.

EXAMPLE 11

This example is concerned with the obtaining of a composition according to the invention containing cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 63,0/27,0/10,0.

A solution of zirconium nitrate and cerium (IV prepared by mixing 264 g of deionized water, 238 g of a solution of nitrate of cerium IV (252 g/l SEO2) and 97 g of a solution of oxynitride zirconium (261 g/l ZrO2). The concentration of this solution was 120 g/l for the oxide.

In a reactor with a stirrer with a volume of 1.5 l was administered to 373 g of deionized water and 111 g of ammonium hydroxide solution (32% NH3).

Was administered for 1 hour, a solution of nitrates. The final pH was close to 9.5.

The suspension, thus obtained, have been matured at 95°C for 2 hours. Then the medium was allowed to cool.

A solution of niobium oxalate (V) was prepared by dissolving under heating to 44.8 g of niobium oxalate (V) in 130 g of deionized water.

This solution was kept at 50°C. the Concentration of this solution amounted to 3.82% for Nb2O5.

A solution of niobium oxalate (V) was administered for 20 minutes to the cooled suspension.

The suspension was filtered and washed.

The precipitate is then introduced into a furnace and calcined at 800°C (thermal pad 4 hours).

EXAMPLE 12

This example is concerned with the obtaining of a composition comprising cerium oxide, zirconium oxide and an oxide n�obia, accordingly, in the following mass ratios: 63,3/26,7/10,0.

A solution of zirconium nitrate and cerium (IV prepared by mixing 451 g of deionized water, 206 g of the nitrate solution of cerium IV (252 g/l SEO2) and 75 g of a solution of oxynitride zirconium (288 g/l ZrO2). The concentration of this solution was 80 g/l of the oxide.

The solution of nitrates is introduced into the autoclave.

The temperature was raised to 100°C. the Medium was kept under stirring at 100°C for 1 hour.

Let cool.

The suspension was transferred into the reactor with stirrer volume of 1.5 liters.

Introduced with stirring a solution of 6 mol/l ammonium hydroxide to obtain a pH close to 9.5.

The suspension was ripened at 95°C for 2 hours.

Then the medium was allowed to cool.

A solution of niobium oxalate (V) was prepared by dissolving under heating 39 g of niobium oxalate (V) in 113 g of deionized water.

This solution was kept at 50°C. the Concentration of this solution was 3,84% Nb2O5.

A solution of niobium oxalate (V) was administered for 20 minutes to the cooled suspension.

Then the pH was again raised to pH 9 by addition of ammonium hydroxide solution (32% NH3).

The suspension was filtered and washed. The precipitate is then introduced into a furnace and calcined at 800°C (thermal pad 4 hours).

EXAMPLE 13

This example is concerned with the obtaining of a composition containing cerium oxide, the oxide C�Rania and niobium oxide, accordingly, in the following mass ratios: 64,0/27,0/9,0.

Acted the same way as in example 12.

However, the solution of niobium oxalate (V) was prepared by dissolving under heating 35,1 g of niobium oxalate (V) in 113 g of deionized water. The concentration of this solution was 3,45% Nb2O5.

COMPARATIVE EXAMPLE 14

This example is concerned with the obtaining of a composition comprising cerium oxide, zirconium oxide and niobium oxide, respectively, in the following mass ratios: 19,4/77,6/3,0.

Preparing a solution of ammonium hydroxide (D, as in example 1 and with the same compounds, but in the following proportions:

- a concentrated solution of ammonium hydroxide: 940 g

- deionized water: g 6730

Prepared also a solution of E, as in example 1 and with the same compounds, but in the following proportions:

- deionized water: 5710 g

- a solution of cerium nitrate (III): 2540 g

- hydrogen peroxide: 298 g

- suspension: 625 g

Then operated as in example 1.

For each of the compositions of the above examples, in the table below, indicate:

- specific surface area BET after calcination for 4 hours at 800°C and 900°C;

- characteristics of acidity.

- the characteristics of resilience.

Acidity

Characteristics of acidity measured by TPD method (TPD), to�which are described below.

Molecular probe used for the study of acid sites in the TPD was the ammonia.

- Preparation of the sample

The sample was adjusted to 500°C in a stream of helium (30 ml/min) at a speed of temperature rise of 20°C/min and kept at this temperature for 30 minutes to remove water vapor and thus to avoid the closure of pores. Finally, the sample was cooled to 100°C in flowing helium at a rate of 10°C/min.

- Adsorption

Then the sample was subjected to flow (30 ml/min), ammonia (5% vol. NH3in helium at 100°C) at atmospheric pressure for 30 minutes (until saturation). The sample was subjected to a helium flow for 1 hour minimum.

- Desorption

TPD (TPD) was performed, performing temperature rise at a rate of 10°C/min until 700°C.

During the rise in temperature was recorded concentration of desorbed substances, i.e. ammonia. The ammonia concentration during the desorption step were determined through calibration changes thermal conductivity of the gaseous flow, measured at the outlet of the cell and a detector of thermal conductivity (RTA) (TCD).

In table 1 the amount of ammonia expressed in ml (normal conditions of temperature and pressure)/m2(the surface at 800°C) composition.

The more ammonia, the more the acidity of the product surface.

The reducing agent�th ability

Characteristics of resilience was measured through recovery programmable of change of temperature (TPV) (TPR) on the device Micromeritics Autochem 2. This device was able to measure the consumption of hydrogen composition depending on temperature.

More precisely, the hydrogen is used as reducing gas with its content of 10%. in argon at a flow rate of 30 ml/min.

The procedure of the experiment is to weigh 200 mg of the sample into a previously weighed container.

Then the sample was injected into a quartz cell containing at the bottom of the quartz wool. Finally, the sample was covered with quartz wool and placed in a furnace measuring device.

The program of temperature change was as follows:

- temperature rise from room temperature to 900°C at a rising rate of 20°C/min in an atmosphere of 10 vol.% N2in Ar.

During this program, the sample temperature was measured using thermocouples placed in a quartz cell above the sample.

The consumption of hydrogen during the recovery stage was determined through calibration changes thermal conductivity of the gaseous flow, measured at the outlet of the cell and a detector of thermal conductivity (RTA) (TCD).

The consumption of hydrogen was measured in the range from 30°C to 900°C.

It is presented in table 1 in ml (normal conditions those�temperature and pressure) N 2on g of the product.

The higher the consumption of hydrogen, the better the resilience characteristics of the product (redox properties).

16
Table 1
Example No.
Ce/Zr/Nb
in %
Specific surface area, m2/gTPD,
ml/m2(acidity)
TPV,
ml H2/g (resilient)
800°C900°C1000°C
No. 1351746,5.10-232,9
63,0/27,0/10,0
No. 241197,86,5.10-229,7
55,1/40,0/4,9
No. 338166,27,3.10-229,4
54,0/39,1/6,9
No. 437125,88,7.10-230,7
77,9/19,5/2,6
No. 530145,66,9.10-229,8
Of 76.6/19,2/4,2
No. 6 28153,99,4.10-232,3
74,2/18,6/7,2
No. 731173,78,3.10-232,5
72,1/18,0/9,9
No. 832123,97,8.10-233,9
68,7/17,2/14,1
No. 919154,59,1.10-219,5
96,8/0/3,2
No. 1034154,18,9.10-221
91,4/0/8,6
No. 1136164,37,5.10-230,4
63,0/27,0/10,0
No. 12471547.10-231,0
63,3/26,7/10,0
No. 134847.10-231,2
64,0/27,0/9,0
No. 1452314,17,6.10-212,6
Comparative
19,4/77,6/3,0

Recall that the magnitude of the resilience of the table are given for the structures subjected to calcination at 800°C for 4 hours.

From table 1 it is seen that the compositions according to the invention show good resilience characteristics and acidity. The composition of comparative example shows good characteristics of acidity, but the characteristics of resilience greatly inferior features�Kam compositions according to the invention.

1. Composition for purification of exhaust gases of internal combustion engines on the basis of cerium oxide containing niobium oxide, with the following mass concentrations:
- niobium oxide of 2 to 20%;
- the rest of the cerium oxide,
which after calcination for 4 hours at 800°C has an acidity of at least 6·10-2in particular at least 7·10-2and this acidity expressed as ml of ammonia on m2composition, and a surface, expressed in m2used to determine the acidity, is a specific surface after calcination for 4 hours at 800°C and the specific surface area of at least 15 m2/g, after calcination for 4 hours at 1000°C has a specific surface area of at least 2 m2/g, in particular at least 3 m2/g.

2. Composition for purification of exhaust gases of internal combustion engines on the basis of cerium oxide, characterized in that it contains niobium oxide and zirconium oxide, with the following mass concentrations:
- cerium oxide, at least 65%;
- niobium oxide from 2 to 12%;
- zirconium oxide up to 48%,
which after calcination for 4 hours at 800°C has an acidity of at least 6·10-2in particular at least 7·10-2and this acidity expressed as ml of ammonia on m2composition, and a surface, expressed in m used to determine the acidity, is a specific surface after calcination for 4 hours at 800°C and after calcination for 4 hours at 1000°C has a specific surface area of at least 2 m2/g, in particular at least 3 m2/g.

3. The composition according to claim 2, characterized in that it additionally contains at least one oxide of an element M selected from the group including tungsten, molybdenum, iron, copper, aluminum, manganese, titanium, vanadium and rare earth elements other than cerium, with the following mass concentrations:
- cerium oxide, at least 65%;
- niobium oxide from 2 to 12%;
- oxide of the element M to 20%;
- the rest is zirconium oxide.

4. The composition according to claim 1, characterized in that it contains niobium oxide in a weight content in the range from 3% to 15%.

5. Composition according to one of claims. 2 or 3, characterized in that it comprises cerium oxide in a weight content of at least 65% and niobium oxide in a weight content in the range from 2 to 10%.

6. The composition according to claim 5, characterized in that it comprises cerium oxide in a weight content of at least 70%, particularly at least 75%.

7. Composition according to one of claims. 1-3, characterized in that it contains niobium oxide in a weight content of less than 10%, in particular in the range from 2% to 10%, and this after�average value is excluded.

8. The composition according to claim 2, characterized in that it after calcination for 4 hours at 800°C has a specific surface area of at least 15 m2/g.

9. Composition according to one of claims. 2 and 3, characterized in that it after calcination for 4 hours at 800°C has a specific surface area of at least 20 m2/g.

10. Composition according to any one of claims. 1-3, characterized in that after calcination for 4 hours at 800°C or 900°C for 4 hours, he has according to the method of x-ray diffraction homogeneous phase corresponding to the cubic phase of ceria.

11. Composition according to any one of claims. 1-3, characterized in that after calcination for 4 hours at 800°C it has the regenerative ability of at least 15, in particular at least 20, more specifically at least 30 ml of hydrogen per gram of product.

12. Catalytic system, characterized in that it comprises a composition according to one of claims. 1-11.

13. Method of cleaning gas, in particular exhaust gas of the engine, characterized in that as a catalyst for the oxidation of CO and hydrocarbons contained in the gas used catalytic system according to claim 12 or the composition according to one of claims. 1-11.

14. The gas purification method, characterized in that for the decomposition of N2O, for adsorption ΝOxand CO2used catalytic system according to claim 12 or the composition according to one of claims. 1-11./p>

15. The method of one of the following reactions: reaction gas water shift reaction with steam, the reaction of isomerization, catalytic cracking reaction, characterized in that the applied catalytic system according to claim 12 or the composition according to one of claims. 1-11.

16. Catalytic process triple action for purification of exhaust gas of a gasoline engine, characterized in that for carrying out this process used catalytic system according to claim 12 or a catalyst prepared on the basis of the composition according to one of claims. 1-11.



 

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4 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a mesoporous carbon-supported copper-based catalyst, a method for production and use thereof in catalytic dehydrogenation of a compound with a C2-C12 alkyl chain to convert said compound to a compound with a corresponding alkenyl chain. The catalyst contains mesoporous carbon, a copper component and an auxiliary element supported on said mesoporous carbon. One or more auxiliary elements (in form of oxides) are selected from a group consisting of V2O5, Li2O, MgO, CaO, Ga2O3, ZnO, Al2O3, CeO2, La2O3, SnO2 and K2O. The amount of the copper component (calculated as CuO) is 2-20 wt % based on the total weight of the catalyst. The amount of the auxiliary element (calculated as said oxide) is 0-3 wt %. The amount of the mesoporous carbon is 77.1-98 wt % based on the total weight of the catalyst. The method of producing the catalyst involves: (1) a step of contacting a copper component precursor, auxiliary element precursor and mesoporous carbon in a given ratio to form an intermediate product and (2) a step of calcining the intermediate product to obtain the mesoporous carbon-supported copper-based catalyst.

EFFECT: catalyst is cheap, environmentally safe and has high thermal stability and caking resistance with considerably high and relatively stable catalytic activity.

19 cl, 47 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a mesoporous carbon-supported copper-based catalyst, a method for production and use thereof in catalytic dehydrogenation of a compound with a C2-C12 alkyl chain to convert said compound to a compound with a corresponding alkenyl chain. The catalyst contains mesoporous carbon, a copper component and an auxiliary element supported on said mesoporous carbon. One or more auxiliary elements (in form of oxides) are selected from a group consisting of V2O5, Li2O, MgO, CaO, Ga2O3, ZnO, Al2O3, CeO2, La2O3, SnO2 and K2O. The amount of the copper component (calculated as CuO) is 2-20 wt % based on the total weight of the catalyst. The amount of the auxiliary element (calculated as said oxide) is 0-3 wt %. The amount of the mesoporous carbon is 77.1-98 wt % based on the total weight of the catalyst. The method of producing the catalyst involves: (1) a step of contacting a copper component precursor, auxiliary element precursor and mesoporous carbon in a given ratio to form an intermediate product and (2) a step of calcining the intermediate product to obtain the mesoporous carbon-supported copper-based catalyst.

EFFECT: catalyst is cheap, environmentally safe and has high thermal stability and caking resistance with considerably high and relatively stable catalytic activity.

19 cl, 47 ex

FIELD: chemistry.

SUBSTANCE: invention relates to methods of obtaining catalyst precursor, catalyst of Fischer-Tropsch synthesis and to method of Fischer-Tropsch synthesis itself. Method of obtaining precursor of catalyst of Fischer-Tropsch synthesis includes stages at which: (i) Fe (II) carboxilate solution is used, (ii) if molar ratio of carboxyl and carboxylate groups, which come into reaction or are capable of coming into reaction with iron, and Fe (II) in solution, used at stage (i), does not constitute, at least, 3:1, source of carboxyl or carboxilate group is added into the solution, for said molar ratio to constitute, at least, 3:1, until Fe (II) carboxylate oxidation is over at the following stage (iii), (iii) Fe (II) carboxylate is processed by oxidant to convert it into Fe (III) carboxilate solution in conditions, which exclude such oxidation simultaneously with dissolution of Fe(0), (iv) hydrolysis of Fe(III) carboxylate, obtained at stage (iii) and precipitation of one or several products of F(III) hydrolysis are carried out, (v) one or several products of hydrolysis, obtained at stage (iv) are reduced, and (vi) source of activator in form of soluble salt of transition metal and chemical activator in form of soluble salt of alkaline metal or alkaline-earth metal are added in the process pr after realisation of any of preceding stages to obtain precursor of catalyst of Fischer-Tropsch synthesis.

EFFECT: achievement of complete dissolution of Fe(0) in acidic solution, source of activator can be introduced before Fe(III) carboxylate hydrolysis.

15 cl, 7 dwg, 1 tbl, 14 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a catalyst for gas-phase oxidation of hydrogen chloride to obtain chloride. Described is a catalyst for oxidation of hydrogen chloride, which contains uranium oxide as a catalytically active component and a support, wherein the support itself is a catalytically active component and the catalyst is pretreated with a stoichiometric mixture of HCl and oxygen at temperature of at least 400°C for at least 10 hours. Described is use of said catalyst in gas-phase catalytic oxidation of hydrogen chloride with oxygen and a method of producing chlorine using the catalyst.

EFFECT: catalyst is distinguished by high stability and activity.

6 cl, 2 tbl, 24 ex

FIELD: process engineering.

SUBSTANCE: invention relates to method of catalyst production. Produced catalyst comprises oxide carrier composed of complex spinel, i.e. Mg [Al, Fe]2O4 and active component, i.e. nickel. Proposed method comprises calcination of modified carrier. It differs from known processes in that oxide carrier surface is, first, impregnated with the solution of cerium or lanthanum salts or mix thereof taken in amount of 5.0-10.0 wt % per oxide carrier. Then, nickel is applied to calcine at 500°C so that catalyst containing 10 wt % of nickel is obtained. Note here that prior to impregnation said oxide carrier is subjected to hydrothermal treatment at partial pressure of steam equal to 1.8-2.0 MPa and gradual increase in reaction zone temperature to 800-900°C at heating rate of 10 degree/min.

EFFECT: higher resistance to coke formation and mechanical strength.

4 ex, 2 tbl

FIELD: chemistry.

SUBSTANCE: described is catalyst for catalytic oxidation of hydrogen chloride, including active component, at least, uranium compound and carrier material, with active component including, at least, uranium oxide or mixture of uranium oxides with stoichiometric composition UO2.1 to UO2.9. Also described is method of obtaining chlorine by catalytic oxidation of hydrogen chloride in presence of described above catalyst in adiabatic mode.

EFFECT: catalyst possesses high stability and activity.

10 cl, 2 tbl, 10 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing isoprene by reacting components of a raw material containing formaldehyde, isobutylene, isobutylene derivatives and isoprene precursors in the presence of a solid-phase acid catalyst which contains niobium phosphate, followed by separation of the end product. The method is characterised by that reaction of formaldehyde with isobutylene, isobutylene derivatives and isoprene precursors is carried out in molar ratio of isobutylene and derivatives thereof to formaldehyde of (3.5-8):1, molar ratio of isobutylene derivatives to isobutylene of (0.75-3.5):1, molar ratio of formaldehyde to isoprene precursors of (4-10):1, the raw material is fed into the reactor at temperature of 140-160°C and pressure of 13-17 atm in form of a continuous gas-liquid stream with volume rate of the gas phase of 20-250 h-1 and of the liquid phase of 10-25 h-1.

EFFECT: use of the present method increases isoprene output and reduces output of high-boiling by-products.

3 cl, 1 dwg

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