RU2747561C1 - Catalyst for synthesis of formic acid and method for production thereof (variants) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be used in production of formic acid by gas-phase oxidation of formaldehyde with oxygen. The catalyst for synthesis of formic acid has the following composition, % wt.: vanadium oxide (V) 4.0 to 25.0; alkaline earth metal oxide 0.5 to 5.0; alkaline earth metal sulfate 0.5 to 7.0; the rest silicon oxide 0.5 to 10.0; titanium oxide (IV). Methods of preparation of the described catalyst are proposed.

EFFECT: inventions allow to synthesize a catalyst for production of formic acid exhibiting stable activity, selectivity, strength at high temperatures in the presence of water vapor.

13 cl, 3 tbl, 4 ex

Description

The invention relates to oxide vanadium-titanium catalysts used to obtain formic acid by gas-phase oxidation of formaldehyde with oxygen.

Formic acid is a valuable chemical product that has found application in organic synthesis (pentaerythritol, asparagam, etc.), the synthesis of formates of various metals. Formic acid is used in agriculture as a preservative in the preparation of feed, as well as in the textile industry, in the application of electroplating, in the production of resins, varnishes and glass.

The main industrial method for producing formic acid is the interaction of carbon monoxide with sodium hydroxide. The process is carried out in two stages: at the first stage, carbon monoxide under a pressure of 0.6-0.8 MPa is passed through sodium hydroxide heated to 120-130 ° C; in the second stage, sodium formate is treated with sulfuric acid and the product is vacuum distilled. The process is multi-stage and not environmentally efficient.

An alternative to the multistage method for the synthesis of formic acid is the catalytic heterogeneous gas-phase oxidation of formaldehyde.

A new method for the synthesis of formic acid by direct oxidation of formaldehyde with atmospheric oxygen at temperatures of 120-180 ° C in the presence of vanadium-titanium oxide catalysts has been developed (Catalysis in Industry, 2013, No. 5, pp. 16-23). As a raw material for this technology, you can use the reaction gases of the oxidation of methanol on an iron-molybdenum catalyst, when formaldehyde is synthesized from methanol, and then formic acid. In contrast to liquid-phase, the gas-phase catalytic method for producing formic acid has a number of advantages: simplicity of the technological scheme with a minimum number of stages; environmental safety; low cost of the final product; low capital investment.

Oxidation of formaldehyde to formic acid proceeds according to the reaction:

НСНО + 0.5О ₂ = НСООН.

Side reactions are:

HCOOH = CO + H ₂ O,

HCOOH + 0.5O ₂ = CO ₂ + H ₂ O,

НСНО + O ₂ = CO ₂ + H ₂ O.

When methanol unconverted in the first stage enters the vanadium-titanium catalyst, methyl formate can also be formed in the second stage:

CH ₃ OH + HCOOH = HCOOCH ₃ + H ₂ O.

The oxidation of formic acid with oxygen is highly exothermic and requires heat removal. To ensure high selectivity of the catalyst, the process is carried out in a narrow temperature range of 120-140 ° C.

Thus, the process of operating a catalyst for the production of formic acid by gas-phase oxidation of formaldehyde with oxygen proceeds under hydrothermal conditions, which indicates the need to use catalysts demonstrating stable activity, selectivity, and physicochemical parameters under hydrothermal conditions (at elevated temperatures under the action of a vapor-gas mixture ).

An urgent task is the development of new effective catalysts for the production of formic acid by gas-phase oxidation of formaldehyde with oxygen for the industrial production of formic acid.

There are two types of vanadium-titanium catalysts for the production of formic acid by gas-phase oxidation of formaldehyde with oxygen - the applied and batch type.

The batch type catalysts contain titanium oxide and vanadium oxide in a wide range from 7.0 to 50.0 wt. %, as well as modifying compounds: one or more metal oxides from group IV and period V of the Periodic Table with the total weight content of modifying metal oxides in the range of 0.1-10.0 wt. %, mainly in the range of 0.1-3.0 wt. %. (patent RU 2356624, IPC B01J 23/22; B01J 21/06; B01J 23/16; C07C 53/02, publ. 27.05.2009), and have the form of granules with one or more through holes and the equivalent diameter of the granules, defined as 6V / S, where V is the volume of the catalyst granule, S is the outer surface area of the catalyst granule, is in the range of 2.0-3.9 mm, preferably 2.4-3.5 mm. (patent RU 2356625, IPC B01J 23/22; B01J 21/06; B01J 23/16; C07C 53/02, publ. 27.05.2009).

Known catalyst of the supported type based on vanadium and titanium oxides for the production of formic acid by gas-phase oxidation of formaldehyde with oxygen (patent RU 2356626, IPC B01J 23/22; B01J 21/06; B01J 23/16; С07С 53/02; В82В 1/00, publ. 27.05.2009), containing mainly _{nanostructured VO x} particles in the form of a monolayer coating of the titanium oxide surface, the content of the crystalline phase of vanadium oxide is no more than 20 wt. %, mainly - not more than 8.0 wt. % of its total content.

The disadvantage of catalysts is their low mechanical strength.

Known catalyst for the production of formaldehyde and methyl formate by one-stage selective oxidation of methanol (patent CN 106890652, IPC B01J 27/053; С07С 41/50; С07С 43/30; С07С 67/40; С07С 69/06, publ. 27.06.2017), containing 10-20 wt. % vanadium-containing raw materials, 55-65 wt. % titanium-containing raw materials and 15-35 wt. % sulfuric acid. The catalyst provides a high conversion rate of methanol, high selectivity, long service life and low sensitivity to temperature fluctuations.

The closest in technical essence to the proposed technical solution is a catalyst for the production of formic acid by gas-phase oxidation of formaldehyde with mixed oxygen and a method for its preparation (patent RU 2235586, IPC B01J 23/22; B01J 21/06; B01J 23/02; С07С 53 / 02, publ. 09/10/2004), which includes vanadium oxides in an amount of 10.0-25.0 wt. %, titanium and additionally contains a modifying compound in the form of one or more oxides of an alkaline earth metal in an amount of 0.5-10.0 wt. %, has a specific surface area of 100-250 m ² / g.

Closest to the claimed method for producing a supported catalyst is a method for preparing vanadium-titanium catalysts (patent RU 2356626, IPC B01J 23/22; B01J 21/06; B01J 23/16; С07С 53/02; В82В 1/00, publ. 27.05 .2009), in which a vanadium oxalate solution is used as the starting vanadium compound, which is prepared by dissolving vanadium in oxalic acid, as the starting titanium compound is titanium oxide, an amorphous or crystalline titanium dioxide hydrogel or xerogel with an anatase structure.

In all the above analogs, the problem of the hydrothermal stability of catalysts has not been solved, although the process of obtaining formic acid proceeds under hydrothermal conditions at a temperature of 120-140 ° C and a water vapor content of 10-15 vol. %. This instability leads to a deterioration in the performance of catalysts under their operating conditions. Thus, there is a current need for catalysts for producing formic acid with improved hydrothermal stability.

The objective of the invention is to develop a hydrothermally stable catalyst for the production of formic acid by gas-phase oxidation of formaldehyde with oxygen while maintaining high strength and activity of the catalyst, and a method for its production.

The problem is solved with the help of a catalyst for the production of formic acid by oxidation of formaldehyde, including oxides of vanadium, titanium and alkaline earth metals. The catalyst additionally contains a modifying compound - sulfate of at least one alkaline earth metal, silicon oxide and has the following composition, wt. %:

Vanadium (V) oxide 4.0-25.0 Alkaline earth metal oxide 0.5-5.0 Alkaline earth metal sulfate 0.5-7.0 Silicon oxide 0.5-10.0 Titanium (IV) oxide rest

Preferably, the catalyst additionally contains cerium oxide in an amount of 0.3-3.0 wt. %.

Preferably, the catalyst contains calcium compounds as alkaline earth metal compounds.

Preferably, the catalyst contains calcium sulfate predominantly in the orthorhombic modification.

Preferably, the catalyst contains titanium oxide of anatase modification with a crystallite size of 9-20 nm as titanium compounds.

Preferably, the catalyst has a surface area of 40-250 m ² / g, a total pore volume of 0.25-0.40 cm ³ / g, an average pore diameter of 9-17 nm, and a strength of 3.5-5.5 MPa.

Preferably, the catalyst granules are in the form of solid cylinders.

The problem is also solved using a method for preparing a catalyst for producing formic acid, including mixing a vanadium compound, at least one alkaline earth metal compound, a modifying compound and titanium dioxide, extrusion molding, drying, heat treatment. When mixing the components, a modifying compound of at least one alkaline earth metal sulfate or sulfuric acid is additionally introduced, or hydrated sulfated titanium dioxide is used in a mixture with titanium dioxide in a ratio of 1: (1-3) and a silicon compound is added to the resulting mixture of components plasticizing additive, the resulting catalyst mass is processed at a temperature of 65-95 ° C for 1-3 hours, then dried to a moisture content of 15-20%, molded, dried and calcined at a temperature of 300-520 ° C.

Preferably, vanadium pentoxide, previously mechanically activated, is used as the vanadium compound.

Preferably, a cerium compound is additionally used as the modifying compound.

Preferably, silicon oxide or calcium silicate is used as the modifying silicon compound.

Preferably, polyvinyl alcohol or urotropine or polyethylene glycols or glycerin is used as a plasticizing additive.

The problem is also solved by a method for preparing a catalyst for producing formic acid, including impregnating a support based on titanium oxide containing at least one alkaline earth metal compound with a solution of vanadium salts, and obtained by molding by extrusion, drying, calcining. To obtain a carrier, a silicon compound, at least one alkaline earth metal sulfate, or sulfuric acid is added to titanium dioxide, or hydrated sulfated titanium dioxide is used in a mixture with titanium dioxide in a ratio of 1: (1-3), the components are mixed by adding an aqueous solution of a plasticizing agent. additives, the obtained catalyst mass is processed at a temperature of 65-95 ° C for 1-3 hours, then dried to a moisture content of 15-20%, granules are formed from the resulting mixture, which are dried at 90-150 ° C and calcined at a temperature of 300- 560 ° C, the resulting support is impregnated with a solution of vanadium salts, followed by drying at 90-150 ° C and calcined in an air stream at a temperature of 300-450 ° C.

The technical result is a hydrothermally stable catalyst for the production of formic acid by gas-phase oxidation of formaldehyde with oxygen with high strength, activity and selectivity, and a method for its production. The catalyst has increased stability in the presence of steam. The increased hydrothermal stability helps to maintain the strength, surface area, porosity and / or pore size of the catalyst when the catalyst is contacted in a vapor / gas mixture.

Preparation of a catalyst for the production of bulk (batch) type formic acid:

1) The mixer is charged with a titanium compound, a vanadium compound and modifying compounds, which are one or more alkaline earth metal compounds, a silicon compound. Additionally, cerium compounds can be introduced.

As a titanium compound, hydrated sulfated titanium dioxide of the anatase modification, or a mixture of titanium dioxide (anatase) with hydrated sulfated titanium oxide (anatase) at a component ratio of 1: (1-3), or with sulfuric acid can be used.

As a precursor of titanium oxide, hydrated sulfated titanium dioxide can be used, which means a compound with the general formula TiO _x (SO ₄ ) _y (OH) _z ⋅nH ₂ O, where x, y, z, n are not integers and vary widely depending on the preparation technology (Chemistry of oxide compounds of titanium, Sverdlovsk, 1988, p. 49). Hydrated sulphated titanium dioxide is obtained by treating hydrated titanium dioxide with a suitable sulphating agent, preferably by treating ilmenite concentrates with sulfuric acid. In the prepared raw material, the content of sulfate ion SO ₄ ^2- in relation to TiO _{2 is} optimally 0.04-0.12. The crystallographic form of titanium dioxide corresponds to the form of anatase or a mixture of anatase with amorphous titanium dioxide.

Titanium hydroxide can be used directly in the form of a hydrogel paste after hydrolysis and washing, or in the form of a powder obtained by drying the hydrogel paste at a temperature not exceeding 150 ° C.

Vanadium (V) oxide, or a mixture of vanadium oxide and its soluble salts (vanadyl oxalate, vanadyl sulfate, ammonium meta-vanadate) can be used as a vanadium compound.

Preferably, the powder of the starting vanadium (V) oxide with a specific surface area of 2-5 m ² / g and a crystallite size of 60-80 nm is processed by grinding in a ball mill in the presence of organic compounds (organic acids, alcohols) for 3-12 hours in order to obtain activated vanadium (V) oxide with a specific surface area of 7-25 m ² / g and a crystallite size of less than 60 nm.

As an alkaline earth metal compound, hydroxides, oxides, nitrates, sulfates, silicates, stearates of alkaline earth metals, or mixtures thereof can be used.

Amorphous silicon dioxide powders, alkaline earth metal silicates, preferably calcium silicate, can be used as the starting silicon compound.

2) The components are mixed until a homogeneous pasty state in the presence of an aqueous solution of a plasticizing additive.

Polyvinyl alcohol, urotropin, polyethylene glycols, glycerin can be used as a plasticizing additive. The use of plasticizing additives ensures the plasticity of the mass during molding.

3) The resulting catalyst mass is processed at a temperature of 65-95 ° C for 1-3 hours, then dried to a moisture content of 15-20%.

4) The resulting paste is extruded through a die with a hole diameter of 3-5 mm, cut into granules in the form of cylinders 4-6 mm long.

5) The resulting granules are dried at 90-150 ° C for 3-8 hours and calcined stepwise in an air stream at a temperature of 300-520 ° C for 3-6 hours.

The finished catalyst includes titanium dioxide of anatase modification with a crystallite size of 9-20 nm, vanadium (V) oxide, calcium sulfate, calcium oxide and is characterized by a specific surface area of 40-250 m ² / g, crushing strength of 3.5-5.5 MPa, total pore volume 0.25-0.40 cm ³ / g, average pore diameter 9-17 nm.

Calcium sulfate in the catalyst may be present in crystallized form, in the form of an orthorhombic and / or hexagonal structure, preferably, that calcium sulfate is present in the form of an orthorhombic structure.

Preparation of a catalyst for the production of supported (impregnating) type formic acid.

Media preparation:

1) The mixer is charged with a titanium compound and a modifying compound, which is one or more alkaline earth metal compounds, a silicon compound, and possibly a cerium compound.

As a titanium compound, hydrated sulfated titanium dioxide of the anatase modification, or a mixture of hydrated titanium dioxide (anatase) with hydrated sulfated titanium oxide (anatase), or with sulfuric acid can be used.

As a modifying compound of an alkaline earth metal, hydroxides, oxides, sulfates, silicates of alkaline earth metals, or mixtures thereof can be used.

2) The components are mixed until a homogeneous pasty state in the presence of an aqueous solution of a plasticizing additive.

3) The resulting mass is processed at a temperature of 65-95 ° C for 1-3 hours, then dried to a moisture content of 15-20%.

4) The resulting paste is extruded through a die with a hole diameter of 3-5 mm, cut into granules with a length of 4-6 mm. The resulting granules are dried at 90-150 ° C for 3-8 hours and calcined stepwise in an air stream at a temperature of 300-560 ° C for 3-6 hours.

Catalyst preparation:

5) Carry out the impregnation of the carrier with a solution of vanadium salts.

6) The resulting granules are dried at 90-150 ° C for 3-8 hours and calcined stepwise in an air flow at a temperature of 300-450 ° C for 3-6 hours.

The specific surface area of the samples was measured on a GKh-1 gasometer in accordance with GOST 23401 by argon adsorption by the BET method.

The pore volume of the carriers in terms of moisture capacity was determined by the amount of moisture absorbed by 1 g of the carrier, previously dried at a temperature of 200 ° C.

The crushing strength of the samples was determined using an MP-9S device using a flat steel spring with a force coefficient of 0.216 kgf / div.

The quantitative determination of the chemical composition of the catalyst was carried out by X-ray fluorescence on a Spectroscan MAKC-GV spectrometer.

The X-ray diffraction study of the samples was carried out on a D8 Advance powder diffractometer (Bruker) in CuK ^α- radiation. The samples were scanned in the range of angles 5-70 (2 ^θ ) with a scanning step of 0.1 and an accumulation time of 7 s at a point. The size of the catalyst particles was estimated from the parameters of the reflections of the X-ray spectrum. After taking into account the contribution of the background scattering, the original spectrum was simulated by functions of the Lorentzian type to calculate the width at half maximum.

The catalytic activity of the samples in the oxidation reaction of formaldehyde to formic acid was determined in a flow-circulation unit at a temperature of 120 ° C with a formaldehyde content of 4-6 vol.% In the initial reaction mixture. %, water vapor 10 vol. %, the rest is air. The catalytic properties of the samples are characterized by the degree of conversion of formaldehyde, selectivity for the reaction products, and the yield of formic acid.

The assessment of the stability of the samples to hydrothermal conditions was carried out by comparing the values of the surface, moisture capacity, and strength before and after the procedure of hydrothermal aging of the finished catalysts. Hydrothermal aging was carried out in a flow-through reactor under severe conditions - at a temperature of 300 ° C and a water vapor content of 30 vol. % in the air stream, processing time - 10 hours.

The samples after hydrothermal aging were dried at 110 ° C for 5 h, after which the physicochemical characteristics were measured and the values obtained were compared with the initial data (Table 2, 3).

Thus, the data obtained indicate that the initial level of catalyst strength is preserved when exposed to the hydrothermal conditions of the reaction medium during the production of formic acid.

Examples.

Examples 1 and 2 show the effect of the composition of the catalyst for the production of formic acid on its physicochemical properties, activity and selectivity.

Example 1. Preparation of a batch type catalyst.

The powder of the initial vanadium (V) oxide with a specific surface area of 5 m ² / g and a crystallite size of 65 nm is processed by grinding in a ball mill in the presence of an oxalic acid solution for 3 h to obtain vanadium (V) oxide with a specific surface area of 21 m ² / g and a crystallite size of 53 nm.

The activated vanadium (V) oxide is loaded into a Z-shaped mixer, a paste of hydrated sulfated titanium dioxide TiO _x (SO ₄ ) _y (OH) _z ⋅nH ₂ O with a TiO ₂ content of 47 wt. % and SO ₄ ² - - 7 wt. %, silicon dioxide powder, add solutions of calcium nitrate, cerium nitrate, calcium sulfate powder, 3% solution of polyvinyl alcohol, mix. The resulting paste is processed at a temperature of 85 ° C for 1 hour, then dried to a moisture content of 18%. The catalyst mass is molded into cuttings with a diameter of 3.5 mm; cuttings are dried at a temperature of 110 ° C, heat treatment is carried out in a stepwise mode in the temperature range of 300-420 ° C for 6 hours in an air stream.

Catalyst composition, wt. %: V ₂ O ₅ - 18.1; CaSO ₄ 5.0; CaO 0.9; SiO ₂ - 0.5; CeO ₂ - 0.3; TiO ₂ - the rest.

Titanium dioxide retains the anatase structure, the CSR of titanium dioxide, as estimated by XRD, is 12 nm.

Calcium sulfate has a 100% orthorhombic structure.

Physicochemical characteristics of the catalyst: specific surface area - 161 m ² / g, total pore volume - 0.33 cm ³ / g, strength - 4.5 MPa, average pore diameter - 9 nm.

The catalyst is tested for activity in the formaldehyde oxidation reaction.

The activity of the catalyst is shown in Table 1.

Example 2. Preparation of an impregnation type catalyst.

1) Preparation of the carrier.

In the Z-shaped mixer, add a paste of hydrated sulfated titanium dioxide, add calcium nitrate solution, calcium silicate powder, sulfuric acid, 3% polyethylene glycol solution, mix. The resulting paste is processed at a temperature of 65 ° C for 1.5 hours, then dried to a moisture content of 15%. The catalyst mass is molded into cuttings with a diameter of 4 mm; cuttings are dried at a temperature of 110 ° C, heat treatment is carried out in a stepwise mode in the temperature range of 300-560 ° C for 6 hours in an air stream.

The resulting support has a specific surface area of 251 m ² / g, a total pore volume of 0.44 cm ³ / g, an average pore diameter of 14.0 nm, and a strength of 4.8 MPa. Titanium dioxide retains the anatase structure; the CSR of titanium dioxide, as estimated by XRD, is 10 nm.

2) Preparation of the catalyst.

An impregnating solution of vanadyl oxalate is prepared by dissolving vanadium pentoxide in an aqueous solution of oxalic acid at a temperature of 70-80 ° C and a mass ratio of H ₂ C ₂ O ₄ : V ₂ O ₅ - 2.5. The carrier is impregnated with the resulting solution in terms of moisture capacity. The catalyst is dried in air for 15-18 hours, dried at 100-120 ° C for 2 hours and calcined in a stream of air at 450 ° C for 4 hours.

Catalyst composition, wt. %: V ₂ O ₅ - 10.5; CaSO ₄ - 7.0; CaSiO ₃ - 5.0; TiO ₂ - the rest.

Physicochemical characteristics of the catalyst: specific surface area - 144 m ² / g, total pore volume - 0.30 cm ³ / g, average pore diameter - 9.0 nm, strength - 4.2 MPa.

Titanium dioxide retains the anatase structure; the CSR of titanium dioxide, as estimated by XRD, is 16 nm.

The catalyst is tested for activity in the synthesis of formic acid by oxidation of formaldehyde.

The activity of the catalyst is shown in Table 1.

The catalysts of the proposed composition are characterized by increased strength compared to the prototype, high activity and selectivity.

Examples 3 and 4 show the stability of the finished catalysts to hydrothermal aging, the data are presented in tables 2 and 3.

Example 3.

The catalyst of the composition according to example 1 was subjected to hydrothermal aging in a flow-through reactor at a temperature of 300 ° C, a water vapor content of 30 vol. %, within 10 hours. After the hydrothermal aging procedure, the sample was dried at 110 ° C for 5 h, after which the physicochemical characteristics were measured and the values obtained were compared with the initial data (Table 2).

Example 4.

The catalyst of the composition according to example 2 was subjected to hydrothermal aging in a flow-type reactor at a temperature of 300 ° C, a water vapor content of 30 vol. %, within 10 hours. After the hydrothermal aging procedure, the sample was dried at 110 ° C for 5 h, after which the physicochemical characteristics were measured and the values obtained were compared with the initial data (Table 3).

Claims (14)

1. Catalyst for producing formic acid by oxidation of formaldehyde, including oxides of vanadium, titanium and alkaline earth metals, characterized in that the catalyst additionally contains a modifying compound - sulfate of at least one alkaline earth metal, silicon oxide and has the following composition, wt. %: Vanadium (V) oxide 4.0-25.0 Alkaline earth metal oxide 0.5-5.0 Alkaline earth metal sulfate 0.5-7.0 Silicon oxide 0.5-10.0 Titanium (IV) oxide rest 2. The catalyst according to claim 1, characterized in that it further contains cerium oxide in an amount of 0.3-3.0 wt. %. 3. The catalyst according to claim 1, characterized in that it contains calcium compounds as alkaline earth metal compounds. 4. The catalyst according to claim 1, characterized in that it contains calcium sulfate mainly in the orthorhombic modification. 5. A catalyst according to claim 1, characterized in that it contains titanium oxide of anatase modification with a crystallite size of 9-20 nm as titanium compounds. 6. A catalyst according to claim 1, characterized in that it has a surface of 40-250 m ² / g, a total pore volume of 0.25-0.40 cm ³ / g, an average pore diameter of 9-17 nm, a strength of 3.5 5.5 MPa. 7. The catalyst according to claim. 1, characterized in that the catalyst granules are in the form of solid cylinders. 8. A method of preparing a catalyst for producing formic acid according to claim 1, comprising mixing a vanadium compound, at least one alkaline earth metal compound, a modifying compound and titanium dioxide, extrusion molding, drying, heat treatment, characterized in that when mixing the components, a modifying agent is additionally introduced a compound of at least one alkaline earth metal sulfate or sulfuric acid or hydrated sulfated titanium dioxide is used in a mixture with titanium dioxide in a ratio of 1: (1-3) and a silicon compound, a plasticizing additive is added to the resulting mixture of components, the resulting catalyst mass is processed at a temperature 65-95 ° C for 1-3 hours, then dried to a moisture content of 15-20%, molded, dried and calcined at a temperature of 300-520 ° C. 9. The method according to claim 6, characterized in that vanadium pentoxide, previously mechanically activated, is used as the vanadium compound. 10. The method according to claim 6, characterized in that a cerium compound is additionally used as the modifying compound. 11. The method according to claim 6, characterized in that silicon oxide or calcium silicate is used as the modifying silicon compound. 12. A method according to claim 6, characterized in that polyvinyl alcohol, or urotropin, or polyethylene glycols, or glycerin is used as the plasticizing additive. 13. A method of preparing a catalyst for producing formic acid according to claim 1, comprising impregnating a titanium oxide-based support containing at least one alkaline earth metal compound with a solution of vanadium salts and obtained by molding by extrusion, drying, calcining, characterized in that for obtaining carrier, a silicon compound, at least one alkaline earth metal sulfate or sulfuric acid is added to titanium dioxide, or hydrated sulfated titanium dioxide is used in a mixture with titanium dioxide in a ratio of 1: (1-3), the components are mixed by adding an aqueous solution of a plasticizing additive, the resulting catalyst the mass is processed at a temperature of 65-95 ° C for 1-3 hours, then dried to a moisture content of 15-20%, granules are formed from the resulting mixture, which are dried at 90-150 ° C and calcined at a temperature of 300-560 ° C, the resulting support is impregnated with a solution of vanadium salts, followed by drying at 90-150 ° C and calcining They are kept in a stream of air at a temperature of 300-450 ° C.