JP2022552169A - Catalyst for cycloalkane dehydrogenation and its production and application - Google Patents

Abstract

The catalyst for cycloalkane dehydrogenation comprises an alumina support, a Group VIII element, Sn element, sulfur element, and at least one dope metal selected from alkali metals, wherein the Group VIII element and Sn element are , VIII3Sn in the form of intermetallic compounds. It also relates to the preparation of said catalyst and its use in cycloalkane dehydrogenation. [Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to a catalyst for cycloalkane dehydrogenation and a method for producing the same, and further to use of the above catalyst in cycloalkane dehydrogenation.

As a clean, efficient and environmentally friendly energy, hydrogen is regarded as the energy with the highest potential for development in the 21st century, and its development and utilization have already attracted worldwide attention. At present, hydrogen gas storage technologies are mainly classified into three types: physical hydrogen storage, adsorption hydrogen storage and chemical hydrogen storage. The technology of physical hydrogen storage places stringent requirements and harsh operating conditions on the hydrogen storage device, making the technology costly to use. Adsorption hydrogen storage and chemical hydrogen storage are the focus of current research. In chemical hydrogen storage, the technique of hydrogen storage with liquid organic hydrides uses a reversible reaction cycle of hydrogenation-dehydrogenation between unsaturated liquid aromatic hydrocarbons and their corresponding cycloalkanes to store hydrogen gas. and release. The hydrogen storage capacity of liquid organic hydrides is much higher than high-pressure compressed hydrogen storage and metal hydride hydrogen storage. In liquid organic hydrides, cycloalkanes are in a liquid state at normal temperature and normal pressure, so this technology can realize long-distance transportation using existing transportation methods for petrochemicals. However, since the dehydrogenation reaction in this process is reversible, the hydrogen production rate is low and side reactions occur, so the purity of the produced hydrogen gas is not high, which increases the separation cost. Therefore, the development of dehydrogenation catalysts with high stability, high conversion and high selectivity is the key to the application of liquid organic hydride hydrogen storage technology.

A commonly used catalyst for cycloalkane dehydrogenation is a supported metal catalyst, and its active component is Pt, Pd, Rh, Ni, Co, or the like. Alumina is the most commonly used support for precious metal dehydrogenation catalysts, and is characterized by its availability and high reaction activity. easy to convert. Reference 1 (Journal of Fuel Chemistry, 1998, 26(6), 543-547) states that the addition of a suitable amount of K ₂ O to a Pt-supported dehydrogenation catalyst can modify the strong acid sites on the catalyst surface. It is reported to help prevent deposit formation and improve catalyst stability. However, this method does not have a clear effect of increasing the selectivity of the catalyst, and cannot solve the problem of side reactions to produce methane. Also, by adding a second metal component such as Ni, Mo, W, Re, Ir, Sn, etc., the dehydrogenation activity of the catalyst can be further improved, and the performance of the catalyst can be improved. CN107376907A discloses a platinum-tin-supported hydrotalcite dehydrogenation catalyst and its preparation method, in which Pt is in a reduced state, Sn coexists in a reduced state and an oxidized state, and a cycloalkane In the dehydrogenation reaction of , the reaction conditions are mild, the selectivity is high, and the hydrogen release rate is high. However, the conversion rate under the condition of low loading of the catalyst needs to be further improved.

In view of the above situation of the prior art, the present inventors sought to find catalysts for cycloalkane dehydrogenation with improved cycloalkane conversion, improved selectivity to aromatic hydrocarbons and stability. Extensive and detailed research has been carried out on catalysts for The present inventors have found a dehydrogenation catalyst comprising an alumina support, a Group VIII element, a Sn element, a sulfur element, and at least one dope metal selected from alkali metals, wherein the catalyst comprises an alkali metal is present in the form of oxides, and the group VIII elements and Sn elements are present in the form of VIII ₃ Sn intermetallic compounds. When used in a cycloalkane dehydrogenation reaction, the catalyst can maintain high conversion, selectivity, and high stability even under conditions where the Group VIII element loading is low. The present invention is based on the above findings.

An object of the present invention is to provide a catalyst that is used in the dehydrogenation reaction that occurs when hydrogen gas is released from cycloalkane. The catalyst can obtain improved cycloalkane conversion and aromatic hydrocarbon selectivity when used in cycloalkane dehydrogenation, and has improved stability.

Another object of the present invention is to provide a method for producing a cycloalkane dehydrogenation catalyst. Not only can the catalyst for cycloalkane dehydrogenation be easily prepared by the method, but the catalyst prepared by the method provides improved cycloalkane conversion and aromatic hydrocarbons when used in cycloalkane dehydrogenation. Selectivity can be obtained and also has improved stability.

A final object of the present invention is to provide the use of the catalyst of the present invention or the catalyst produced by the process of the present invention as a catalyst in the dehydrogenation of cycloalkanes. In such applications, improved cycloalkane conversion and aromatic hydrocarbon selectivity can be obtained with improved stability.

Technical proposals that can achieve the above object of the present invention are summarized as follows.

1. A catalyst for cycloalkane dehydrogenation, comprising an alumina support, a Group VIII element, Sn element, sulfur element, and at least one dope metal selected from alkali metals, wherein the Group VIII element and Sn The elements are present in the form of VIII ₃ Sn intermetallic compounds.

2. In the catalyst according to item 1, the alumina support has a specific surface area of 150 m ² /g or more, a pore volume of 0.5 cm ³ /g or more, and an average pore diameter of 70 to 200 Å, preferably , a specific surface area of 210 m ² /g or more, a pore volume of 0.55 cm ³ /g or more, and an average pore diameter of 80 to 150 Å.

3. In the catalyst according to item 1 or 2, the Group VIII element is one or more selected from Pt, Pd, Ir, preferably Pt, and the content, based on the weight of the catalyst, is 0.2 to 5.0 wt%, preferably 0.3 to 2.0 wt%.

4. In the catalyst according to any one of items 1 to 3, the Sn element has a content of 0.04 to 1.0 wt%, preferably 0.06 to 0.4 wt%, based on the weight of the catalyst. %.

5. In the catalyst according to any one of items 1 to 4, elemental sulfur has a content of 0.1 to 3 wt%, preferably 0.3 to 1 wt%, based on the weight of the catalyst.

6. In the catalyst according to any one of items 1 to 5, the content of the alkali metal element is 0.1 to 1 wt%, preferably 0.2 to 0.5 wt%, based on the weight of the catalyst. is.

7. The method for producing the catalyst according to any one of items 1 to 6,
a. a step of uniformly mixing an aluminum source and a binder, then kneading and extruding into strips to obtain an alumina carrier;
b. After drying and calcining, loading the group VIII element and the Sn element;
c. After drying and calcining, adding an alkali metal compound;
d. calcination, reduction treatment to cause the alkali metal to be present in the form of an oxide and the supported metal to be present in the form of a VIII ₃ Sn intermetallic compound;
Sulfur or sulfur compounds may be present in the aluminum source or added to the alumina support during or after manufacture of the alumina support.

8. In the method according to item 7, the aluminum source is one or more selected from pseudoboehmite, boehmite and aluminum hydroxide, preferably pseudoboehmite.

9. In the method according to paragraphs 7 or 8, the sulfur or sulfur compound is one or more selected from sulfur powder, sulfuric acid and sulfate.

10. In the method according to any one of items 7 to 9, ion exchange, impregnation or precipitation using a group VIII element metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex or mixture thereof as a raw material Supporting of the group VIII element is realized by the method of

11. In the method according to any one of items 7 to 10, the metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex, or mixture thereof of Sn element is used as a raw material, and is sequentially impregnated or co-impregnated. Carrying of Sn element is realized.

12. In the method according to any one of clauses 7-11, in step b, the molar ratio n _VIII :n _Sn of group VIII element and Sn element is between 2 and 4, preferably between 2.5 and 3. .5.

13. In the method according to any one of items 7 to 12, ion exchange, impregnation or precipitation is performed using a metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex or a mixture thereof of an alkali metal element as a raw material. The supporting of the alkali metal element is realized by the method.

14. In the method according to any one of Items 7 to 13, the Group VIII element and the Sn element are supported, then dried, left to stand and then fired, and the firing temperature is 300 to 750 ° C., and the firing time is 1. ~12 hours.

15. 15. The method according to any one of items 7 to 14, wherein the catalyst is reduced with a reducing agent such as hydrogen gas before using the catalyst, the reduction temperature is 350 to 800° C., and the reduction time is 0.5 to 24 It's time.

16. Use of the catalyst according to any one of claims 1-6 in cycloalkane dehydrogenation.

These and other objects, features and advantages of the present invention will become readily apparent to those skilled in the art after considering the present invention with reference to the following.

1 shows the atomic structures of PtSn and Pt ₃ Sn intermetallics. 1 shows XRD diffractograms of Pt, PtSn and Pt ₃ Sn intermetallic compounds in Comparative Example 1, Comparative Example 3 and Example 1. FIG.

A catalyst for cycloalkane dehydrogenation according to an aspect of the present invention comprises an alumina support, a Group VIII element, a Sn element, a sulfur element, and at least one dope metal selected from alkali metals, Group VIII elements and Sn elements exist in the form of VIII ₃ Sn intermetallic compounds.

In a catalyst containing two or more kinds of metals, the metal particles form intermetallic compounds with different compounding ratios, in addition to existing in the state of a single substance or an alloy. An intermetallic compound means a stoichiometric compound formed between two or more metals.

In one embodiment, relative to the alumina support, the porous support has a specific surface area of 150 m ² /g or more, a pore volume of 0.5 cm ³ /g or more, and an average pore diameter of 70 to 200 Å. It preferably has a specific surface area of 210 m ² /g or more, a pore volume of 0.55 cm ³ /g or more, and an average pore diameter of 80 to 150 Å.

Preferably, in the catalyst, the Group VIII element is one or more selected from Pt, Pd, Ir, preferably Pt, and the content is 0.2 based on the weight of the catalyst. ~5.0 wt%, preferably 0.3-2.0 wt%.

Preferably, in the catalyst, the Sn element has a content of 0.04 to 1.0 wt%, preferably 0.06 to 0.4 wt%, based on the weight of the catalyst.

Preferably, in the catalyst, elemental sulfur has a content of 0.1 to 3 wt%, preferably 0.3 to 1 wt%, based on the weight of the catalyst.

Preferably, in the catalyst, the alkali metal is one or more selected from Li, Na, K, Rb, preferably K, and the content is 0.1 based on the weight of the catalyst. ~1 wt%, preferably 0.2-0.5 wt%.

The method for producing the catalyst of the present invention according to the second aspect of the present invention comprises:
a. a step of uniformly mixing an aluminum source and a binder, then kneading and extruding into strips to obtain an alumina carrier;
b. After drying and calcining, loading the group VIII element and the Sn element;
c. After drying and calcining, adding an alkali metal compound;
d. calcination, reduction treatment to cause the alkali metal to be present in the form of an oxide and the supported metal to be present in the form of a VIII ₃ Sn intermetallic compound;
Sulfur or sulfur compounds may be present in the aluminum source or added to the alumina support during or after manufacture of the alumina support.

In one embodiment, the aluminum source, binder, etc. are uniformly mixed, then kneaded, extruded into strips, dried and calcined to obtain a shaped alumina carrier. Here, the steps of kneading, strip extrusion, drying, and baking are not particularly limited, and any method known in the art can be used.

Preferably, the aluminum source is one or more selected from pseudoboehmite, boehmite, aluminum hydroxide, preferably pseudoboehmite.

Preferably, the binder is one or more selected from nitric acid, sesbania powder, polyacrylamide, methylcellulose, polyvinyl alcohol, sodium carboxymethylcellulose, preferably nitric acid, sesbania powder and methylcellulose.

In a preferred embodiment, the sulfur or sulfur compound may be pre-existing in the aluminum source for making the catalyst support or may be dispersed in the catalyst support during or after making the catalyst support. Examples include sulfur powder and sulfur compounds such as sulfates, sulfuric acid, including aluminum sulfate, ammonium sulfate, and the like. From the viewpoint that sulfur may be dispersed in the carrier, sulfur compounds that are soluble in water or organic solvents are preferred, and examples of such sulfur compounds include sulfuric acid, aluminum sulfate, and ammonium sulfate.

Preferably, metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex or a mixture thereof of group VIII element is used as raw material, and ion exchange, impregnation or precipitation method is used to realize the support of group VIII element.

Preferably, the Sn element is supported by sequential impregnation or co-impregnation using a metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex, or a mixture thereof as raw materials of Sn element.

Preferably, in step b, the molar ratio n _VIII :n _Sn of group VIII elements and Sn elements is between 2 and 4, preferably between 2.5 and 3.5.

After supporting the Group VIII element and Sn element, the acidity of the surface of the catalyst is adjusted by adding an alkali metal. Preferably, the metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex, or mixture thereof of the alkali metal element is used as the starting material, and the alkali metal element is supported by ion exchange, impregnation, or precipitation.

In a preferred embodiment, the catalyst of the present invention is allowed to stand for an appropriate period of time, for example, 24 hours after supporting the Group VIII element and the Sn element, and then slowly stirred at, for example, about 30° C. to remove the surface of the catalyst. Evaporate the water, dry, and calcine after standing overnight at a suitable room temperature, with a calcination temperature of 300-750° C. and a calcination time of 1-12 hours. Group VIII elements and Sn elements are present in the form of VIII ₃ Sn intermetallic compounds. After adding the alkali metal element, it is fired again, the firing temperature is 300-500° C., and the firing time is 1-12 hours.

In a preferred embodiment, the catalyst of the present invention is subjected to a reduction treatment prior to use, and conventional catalyst reduction methods can be used, i.e., an external catalyst is reduced by contacting the catalyst with a reducing agent, such as hydrogen gas, to reduce the catalyst. Pre-reduction or in-line reduction is achieved. Preferably, the reduction temperature is 350-800° C. and the reduction time is 0.5-24 hours.

According to a last aspect of the invention there is provided the use of the catalyst of the invention or the catalyst produced by the process of the invention as a catalyst in the dehydrogenation of cycloalkanes.

In a preferred embodiment, the cycloalkane is one or more selected from methylcyclohexane, cyclohexane and decahydronaphthalene, preferably methylcyclohexane or cyclohexane.

In a preferred embodiment, the dehydrogenation reaction is carried out in a fixed bed reactor starting with methylcyclohexane. The catalyst loading varies according to the reactor volume. By performing a reduction treatment on the catalyst before supply, the supported metal is present in the form of a single substance, and the reduction conditions are a hydrogen gas pressure of 0.1 to 10 MPa, a temperature of 300 to 800 ° C., and a time of is 0.5 to 24 hours, and preferred conditions are hydrogen gas pressure of 0.2 to 5 MPa, temperature of 300 to 550° C., and time of 3 to 8 hours. The reaction conditions are a hydrogen gas pressure of 0.1-10 MPa, a temperature of 250-500° C., a weight hourly space velocity of 0.5-20 h ⁻¹ , and a molar ratio of hydrogen to oil of 0-15. The preferred conditions are a hydrogen gas pressure of 0.2-2 MPa, a temperature of 300-450° C., a weight hourly space velocity of 1-10 h ⁻¹ , and a molar ratio of hydrogen to oil of 1-10. be.

The following examples further illustrate the invention, but the invention is not limited to the following examples.

Comparative example 1
10 g of pseudoboehmite was impregnated with an aluminum sulfate solution having a sulfur content of 0.5 wt% by an impregnation method, and the obtained S-containing aluminum powder, 0.2 g of sesbania powder, and 0.2 g of carboxymethyl cellulose were uniformly mixed. After mixing, 12.5 g of 3.6 wt % nitric acid is added dropwise while stirring, the mixture is transferred to a kneader and kneaded for about 1 hour, and extruded with a strip extruder after fully kneading the powder (1 diameter ~2 mm and about 5 mm in length). After drying the extruded strip carrier at 120° C. for 12 hours, it is calcined at 700° C. for 3 hours to obtain a shaped carrier.

After being impregnated with H ₂ PtCl ₂ solution (containing 0.00748 g of Pt per mL) by pore-filling impregnation method, let stand for 24 hours, then vacuum dry at 60° C. for 3 hours, dry at 120° C. for 12 hours, Bake at 400° C. for 3 hours.

2 mL of the prepared catalyst is in-line reduced with pure hydrogen gas to obtain a 0.5 wt % Pt/Al ₂ O ₃ catalyst. The reduction condition is a hydrogen gas flow rate of 50 mL/min. The temperature is raised to 400° C. at 10° C./min, and after constant temperature for 1 hour, the temperature is lowered to the reaction temperature in a hydrogen gas stream. The feed oil, methylcyclohexane, is introduced and reacted, and the product is analyzed by gas chromatography. The reaction conditions are a temperature of 320° C. and a reaction pressure of 0.4 MPa. The liquid hourly space velocity of methylcyclohexane is 2h ⁻¹ and the hydrogen to oil ratio (mol/mol) is 2. Table 1 shows the results of the dehydrogenation reaction of methylcyclohexane after 5 hours. Table 2 shows the results of the dehydrogenation reaction of methylcyclohexane after 24 hours.

Comparative example 2
10 g of pseudo-boehmite, 0.2 g of sesbania powder, and 0.2 g of carboxymethyl cellulose were weighed and uniformly mixed, then 12.5 g of 3.6 wt % nitric acid was added dropwise while stirring, and the mixture was transferred to a kneader. For about 1 hour, the powder is fully kneaded and then extruded with a strip extruder (1-2 mm in diameter and about 5 mm in length). After drying the extruded strip carrier at 120° C. for 12 hours, it is calcined at 700° C. for 3 hours to obtain a shaped carrier.

After being impregnated with H ₂ PtCl ₂ solution (containing 0.00748 g of Pt per mL) by pore-filling impregnation method, let stand for 24 hours, then vacuum dry at 60° C. for 3 hours, dry at 120° C. for 12 hours, A single platinum catalyst is obtained by calcining at 400° C. for 3 hours.

After reducing the prepared single platinum catalyst with pure hydrogen gas, it was impregnated with SnCl2 solution by pore _- filling impregnation method, the molar ratio of _nPt : _nSn = 3, and was placed at 30 °C after standing for 24 hours. evaporate water on the surface while stirring at , then dry at 120° C. for 12 hours, and bake at 400° C. for 3 hours. Then _, it is impregnated with KNO3 solution by pore filling impregnation method, the amount of K supported is 0.3 wt%, left to stand for 24 hours, dried at 120° C. for 12 hours, and calcined at 400° C. for 3 hours.

2 mL of the prepared catalyst is in-line reduced with pure hydrogen gas to obtain a 0.5 wt% Pt--Sn--K ₂ O/Al ₂ O ₃ catalyst. The reduction condition is a hydrogen gas flow rate of 50 mL/min. The temperature is raised to 400° C. at 10° C./min, and after constant temperature for 1 hour, the temperature is lowered to the reaction temperature in a hydrogen gas stream. The feed oil, methylcyclohexane, is introduced and reacted, and the product is analyzed by gas chromatography. The reaction conditions are a temperature of 320° C. and a reaction pressure of 0.4 MPa. The liquid hourly space velocity of methylcyclohexane is 2h ⁻¹ and the hydrogen to oil ratio (mol/mol) is 2. Table 1 shows the results of the dehydrogenation reaction of methylcyclohexane after 5 hours. Table 2 shows the results of the dehydrogenation reaction of methylcyclohexane after 24 hours.

Comparative Example 3 (PtSn structure)
10 g of pseudoboehmite was impregnated with an aluminum sulfate solution having a sulfur content of 0.5 wt% by an impregnation method, and the obtained S-containing aluminum powder, 0.2 g of sesbania powder, and 0.2 g of carboxymethyl cellulose were uniformly mixed. After mixing, 12.5 g of 3.6 wt % nitric acid is added dropwise while stirring, the mixture is transferred to a kneader and kneaded for about 1 hour, and extruded with a strip extruder after fully kneading the powder (1 diameter ~2 mm and about 5 mm in length). After drying the extruded strip carrier at 120° C. for 12 hours, it is calcined at 700° C. for 3 hours to obtain a shaped carrier.

After being impregnated with H ₂ PtCl ₂ solution (containing 0.00748 g of Pt per mL) by pore-filling impregnation method, let stand for 24 hours, then vacuum dry at 60° C. for 3 hours, dry at 120° C. for 12 hours, A single platinum catalyst is obtained by calcining at 400° C. for 3 hours.

After reducing the prepared single platinum catalyst with pure hydrogen gas, it was impregnated with SnCl2 solution by pore _- filling impregnation method, the molar ratio of _nPt : _nSn = 0.6, and after standing for 24 hours Moisture on the surface is evaporated while stirring at 30°C, then dried at 120°C for 12 hours and calcined at 400°C for 3 hours. Then _, it is impregnated with KNO3 solution by pore filling impregnation method, the amount of K supported is 0.3 wt%, left to stand for 24 hours, dried at 120° C. for 12 hours, and calcined at 400° C. for 3 hours.

2 mL of the prepared catalyst is in-line reduced with pure hydrogen gas to obtain 0.5 wt% Pt--Sn--K ₂ O/S--Al ₂ O ₃ catalyst. The reduction condition is a hydrogen gas flow rate of 50 mL/min. The temperature is raised to 400° C. at 10° C./min, and after constant temperature for 1 hour, the temperature is lowered to the reaction temperature in a hydrogen gas stream. The feed oil, methylcyclohexane, is introduced and reacted, and the product is analyzed by gas chromatography. The reaction conditions are a temperature of 320° C. and a reaction pressure of 0.4 MPa. The liquid hourly space velocity of methylcyclohexane is 2h ⁻¹ and the hydrogen to oil ratio (mol/mol) is 2. Table 1 shows the results of the dehydrogenation reaction of methylcyclohexane after 5 hours. Table 2 shows the results of the dehydrogenation reaction of methylcyclohexane after 24 hours.

Example 1 (Pt ₃ Sn structure)
10 g of pseudoboehmite was impregnated with an aluminum sulfate solution having a sulfur content of 0.5 wt% by an impregnation method, and the obtained S-containing aluminum powder, 0.2 g of sesbania powder, and 0.2 g of carboxymethyl cellulose were uniformly mixed. After mixing, 12.5 g of 3.6 wt % nitric acid is added dropwise while stirring, the mixture is transferred to a kneader and kneaded for about 1 hour, and extruded with a strip extruder after fully kneading the powder (1 diameter ~2 mm and about 5 mm in length). After drying the extruded strip carrier at 120° C. for 12 hours, it is calcined at 700° C. for 3 hours to obtain a shaped carrier.

After being impregnated with H ₂ PtCl ₂ solution (containing 0.00748 g of Pt per mL) by pore-filling impregnation method, let stand for 24 hours, then vacuum dry at 60° C. for 3 hours, dry at 120° C. for 12 hours, A single platinum catalyst is obtained by calcining at 400° C. for 3 hours.

After reducing the prepared single platinum catalyst with pure hydrogen gas, it was impregnated with SnCl2 solution by pore _- filling impregnation method, the molar ratio of _nPt : _nSn = 3, and was placed at 30 °C after standing for 24 hours. evaporate water on the surface while stirring at , then dry at 120° C. for 12 hours, and bake at 400° C. for 3 hours. Then _, it is impregnated with KNO3 solution by pore filling impregnation method, the amount of K supported is 0.3 wt%, left to stand for 24 hours, dried at 120° C. for 12 hours, and calcined at 400° C. for 3 hours.

2 mL of the prepared catalyst is in-line reduced with pure hydrogen gas to obtain 0.5 wt% Pt--Sn--K ₂ O/S--Al ₂ O ₃ catalyst. The reduction condition is a hydrogen gas flow rate of 50 mL/min. The temperature is raised to 400° C. at 10° C./min, and after constant temperature for 1 hour, the temperature is lowered to the reaction temperature in a hydrogen gas stream. The feed oil, methylcyclohexane, is introduced and reacted, and the product is analyzed by gas chromatography. The reaction conditions are a temperature of 320° C. and a reaction pressure of 0.4 MPa. The liquid hourly space velocity of methylcyclohexane is 2h ⁻¹ and the hydrogen to oil ratio (mol/mol) is 2. Table 1 shows the results of the dehydrogenation reaction of methylcyclohexane after 5 hours. Table 2 shows the results of the dehydrogenation reaction of methylcyclohexane after 24 hours.

Example 2 (Pt ₃ Sn structure)
10 g of pseudoboehmite was impregnated with an aluminum sulfate solution having a sulfur content of 0.5 wt% by an impregnation method, and the obtained S-containing aluminum powder, 0.2 g of sesbania powder, and 0.2 g of carboxymethyl cellulose were uniformly mixed. After mixing, 12.5 g of 3.6 wt % nitric acid is added dropwise while stirring, the mixture is transferred to a kneader and kneaded for about 1 hour, and extruded with a strip extruder after fully kneading the powder (1 diameter ~2 mm and about 5 mm in length). After drying the extruded strip carrier at 120° C. for 12 hours, it is calcined at 700° C. for 3 hours to obtain a shaped carrier.

After being impregnated with H ₂ PtCl ₂ solution (containing 0.00748 g of Pt per mL) by pore-filling impregnation method, let stand for 24 hours, then vacuum dry at 60° C. for 3 hours, dry at 120° C. for 12 hours, A single platinum catalyst is obtained by calcining at 400° C. for 3 hours.

After reducing the prepared single platinum catalyst with pure hydrogen gas, it was impregnated with SnCl2 solution by pore _- filling impregnation method, the molar ratio of _nPt : _nSn = 3.4, and after standing for 24 hours Moisture on the surface is evaporated while stirring at 30°C, then dried at 120°C for 12 hours and calcined at 400°C for 3 hours. Then _, it is impregnated with KNO3 solution by pore filling impregnation method, the amount of K supported is 0.3 wt%, left to stand for 24 hours, dried at 120° C. for 12 hours, and calcined at 400° C. for 3 hours.

2 mL of the prepared catalyst is in-line reduced with pure hydrogen gas to obtain 0.5 wt% Pt--Sn--K ₂ O/S--Al ₂ O ₃ catalyst. The reduction condition is a hydrogen gas flow rate of 50 mL/min. The temperature is raised to 400° C. at 10° C./min, and after constant temperature for 1 hour, the temperature is lowered to the reaction temperature in a hydrogen gas stream. The feed oil, methylcyclohexane, is introduced and reacted, and the product is analyzed by gas chromatography. The reaction conditions are a temperature of 320° C. and a reaction pressure of 0.4 MPa. The liquid hourly space velocity of methylcyclohexane is 2h ⁻¹ and the hydrogen to oil ratio (mol/mol) is 2. Table 1 shows the results of the dehydrogenation reaction of methylcyclohexane after 5 hours. Table 2 shows the results of the dehydrogenation reaction of methylcyclohexane after 24 hours.

Example 3 (Pt ₃ Sn structure)
10 g of pseudo-boehmite was impregnated with an aluminum sulfate solution having a sulfur loading of 0.8 wt% by an impregnation method, and the obtained S-containing aluminum powder, 0.2 g of Sesbania powder, and 0.2 g of carboxymethyl cellulose were uniformly mixed. After mixing, 12.5 g of 3.6 wt % nitric acid is added dropwise while stirring, the mixture is transferred to a kneader and kneaded for about 1 hour, and extruded with a strip extruder after fully kneading the powder (1 diameter ~2 mm and about 5 mm in length). After drying the extruded strip carrier at 120° C. for 12 hours, it is calcined at 700° C. for 3 hours to obtain a shaped carrier.

After being impregnated with H ₂ PtCl ₂ solution (containing 0.00748 g of Pt per mL) by pore-filling impregnation method, let stand for 24 hours, then vacuum dry at 60° C. for 3 hours, dry at 120° C. for 12 hours, A single platinum catalyst is obtained by calcining at 400° C. for 3 hours.

After reducing the prepared single platinum catalyst with pure hydrogen gas, it was impregnated with SnCl2 solution by pore _- filling impregnation method, the molar ratio of _nPt : _nSn = 3, and was placed at 30 °C after standing for 24 hours. evaporate water on the surface while stirring at , then dry at 120° C. for 12 hours, and bake at 400° C. for 3 hours. Then _, it is impregnated with KNO3 solution by pore filling impregnation method, the amount of K supported is 0.3 wt%, left to stand for 24 hours, dried at 120° C. for 12 hours, and calcined at 400° C. for 3 hours.

2 mL of the prepared catalyst is in-line reduced with pure hydrogen gas to obtain 0.5 wt% Pt--Sn--K ₂ O/S--Al ₂ O ₃ catalyst. The reduction condition is a hydrogen gas flow rate of 50 mL/min. The temperature is raised to 400° C. at 10° C./min, and after constant temperature for 1 hour, the temperature is lowered to the reaction temperature in a hydrogen gas stream. The feed oil, methylcyclohexane, is introduced and reacted, and the product is analyzed by gas chromatography. The reaction conditions are a temperature of 320° C. and a reaction pressure of 0.4 MPa. The liquid hourly space velocity of methylcyclohexane is 2h ⁻¹ and the hydrogen to oil ratio (mol/mol) is 2. Table 1 shows the results of the dehydrogenation reaction of methylcyclohexane after 5 hours. Table 2 shows the results of the dehydrogenation reaction of methylcyclohexane after 24 hours.

Example 4 (Pt ₃ Sn structure)
10 g of pseudo-boehmite was impregnated with an aluminum sulfate solution having a sulfur loading of 0.3 wt% by an impregnation method, and the obtained S-containing aluminum powder, 0.2 g of Sesbania powder, and 0.2 g of carboxymethyl cellulose were uniformly mixed. After mixing, 12.5 g of 3.6 wt % nitric acid is added dropwise while stirring, the mixture is transferred to a kneader and kneaded for about 1 hour, and extruded with a strip extruder after fully kneading the powder (1 diameter ~2 mm and about 5 mm in length). After drying the extruded strip carrier at 120° C. for 12 hours, it is calcined at 700° C. for 3 hours to obtain a shaped carrier.

After being impregnated with H ₂ PtCl ₂ solution (containing 0.00748 g of Pt per mL) by pore-filling impregnation method, let stand for 24 hours, then vacuum dry at 60° C. for 3 hours, dry at 120° C. for 12 hours, A single platinum catalyst is obtained by calcining at 400° C. for 3 hours.

After reducing the prepared single platinum catalyst with pure hydrogen gas, it was impregnated with SnCl2 solution by pore _- filling impregnation method, the molar ratio of _nPt : _nSn = 3, and was placed at 30 °C after standing for 24 hours. evaporate water on the surface while stirring at , then dry at 120° C. for 12 hours, and bake at 400° C. for 3 hours. Then _, it is impregnated with KNO3 solution by pore filling impregnation method, the amount of K supported is 0.3 wt%, left to stand for 24 hours, dried at 120° C. for 12 hours, and calcined at 400° C. for 3 hours.

2 mL of the prepared catalyst is in-line reduced with pure hydrogen gas to obtain 0.5 wt% Pt--Sn--K ₂ O/S--Al ₂ O ₃ catalyst. The reduction condition is a hydrogen gas flow rate of 50 mL/min. The temperature is raised to 400° C. at 10° C./min, and after constant temperature for 1 hour, the temperature is lowered to the reaction temperature in a hydrogen gas stream. The feed oil, methylcyclohexane, is introduced and reacted, and the product is analyzed by gas chromatography. The reaction conditions are a temperature of 320° C. and a reaction pressure of 0.4 MPa. The liquid hourly space velocity of methylcyclohexane is 2h ⁻¹ and the hydrogen to oil ratio (mol/mol) is 2. Table 1 shows the results of the dehydrogenation reaction of methylcyclohexane after 5 hours. Table 2 shows the results of the dehydrogenation reaction of methylcyclohexane after 24 hours.

Example 5 (Pt ₃ Sn structure)
10 g of pseudoboehmite was impregnated with an aluminum sulfate solution having a sulfur content of 0.5 wt% by an impregnation method, and the obtained S-containing aluminum powder, 0.2 g of sesbania powder, and 0.2 g of carboxymethyl cellulose were uniformly mixed. After mixing, 12.5 g of 3.6 wt % nitric acid is added dropwise while stirring, the mixture is transferred to a kneader and kneaded for about 1 hour, and extruded with a strip extruder after fully kneading the powder (1 diameter ~2 mm and about 5 mm in length). After drying the extruded strip carrier at 120° C. for 12 hours, it is calcined at 700° C. for 3 hours to obtain a shaped carrier.

After being impregnated with H ₂ PtCl ₂ solution (containing 0.00748 g of Pt per mL) by pore-filling impregnation method, let stand for 24 hours, then vacuum dry at 60° C. for 3 hours, dry at 120° C. for 12 hours, A single platinum catalyst is obtained by calcining at 400° C. for 3 hours.

After reducing the prepared single platinum catalyst with pure hydrogen gas, it was impregnated with SnCl2 solution by pore _- filling impregnation method, the molar ratio of _nPt : _nSn = 3, and was placed at 30 °C after standing for 24 hours. evaporate water on the surface while stirring at , then dry at 120° C. for 12 hours, and bake at 400° C. for 3 hours. Then _, it is impregnated with KNO3 solution by pore filling impregnation method, the amount of K supported is 0.3 wt%, left to stand for 24 hours, dried at 120° C. for 12 hours, and calcined at 400° C. for 3 hours.

2 mL of the prepared catalyst is in-line reduced with pure hydrogen gas to obtain 0.5 wt% Pt--Sn--K ₂ O/S--Al ₂ O ₃ catalyst. The reduction condition is a hydrogen gas flow rate of 50 mL/min. The temperature is raised to 400° C. at a rate of 10° C./min, and after constant temperature for 1 hour, the temperature is raised to the reaction temperature in a hydrogen gas stream. Cyclohexane, which is a raw material oil, is introduced and reacted, and the product is analyzed by gas chromatography. The reaction conditions are a temperature of 480° C. and a reaction pressure of 0.4 MPa. The liquid hourly space velocity of cyclohexane is 2h ⁻¹ and the hydrogen to oil ratio (mol/mol) is 4. Table 3 shows the results of the cyclohexane dehydrogenation reaction after 5 hours and 24 hours.

以上の実施例及び比較例から分かるように、本発明に係る触媒は、メチルシクロヘキサン及びシクロヘキサンの脱水素反応に用いられる場合、より高いシクロアルカン転化率及び芳香族炭化水素選択性を有し、かつ安定性がより高い。

As can be seen from the above examples and comparative examples, the catalyst according to the present invention has higher cycloalkane conversion and aromatic hydrocarbon selectivity when used for the dehydrogenation reaction of methylcyclohexane and cyclohexane, and More stable.

The above descriptions are merely preferred embodiments of the present invention, and for those skilled in the art, any improvements and modifications made within the principle of the present invention shall also fall within the protection scope of the present invention. should be considered.

Claims (16)

Alumina support, Group VIII element, Sn element, sulfur element, and at least one doping metal selected from alkali metals, wherein the Group VIII element and Sn element are VIII ₃ Sn intermetallic compound A catalyst for cycloalkane dehydrogenation, present in the form The alumina carrier has a specific surface area of 150 m ² /g or more, a pore volume of 0.5 cm ³ /g or more, an average pore diameter of 70 to 200 Å, and preferably a specific surface area of 210 m ² /g or more. , a pore volume of 0.55 cm ³ /g or more, and an average pore diameter of 80 to 150 Å. The Group VIII element is one or more selected from Pt, Pd, and Ir, preferably Pt, and has a content of 0.2 to 5.0 wt% based on the weight of the catalyst; Catalyst according to claim 1 or 2, preferably between 0.3 and 2.0 wt%. The Sn element according to any one of claims 1 to 3, having a content of 0.04 to 1.0 wt%, preferably 0.06 to 0.4 wt%, based on the weight of the catalyst. catalyst. Catalyst according to any one of the preceding claims, wherein elemental sulfur has a content of 0.1-3 wt%, preferably 0.3-1 wt%, based on the weight of the catalyst. The alkali metal element according to any one of claims 1 to 5, having a content of 0.1 to 1 wt%, preferably 0.2 to 0.5 wt%, based on the weight of the catalyst. catalyst. A method for producing the catalyst according to any one of claims 1 to 6,
a. a step of uniformly mixing an aluminum source and a binder, then kneading and extruding into strips to obtain an alumina carrier;
b. After drying and calcining, loading the group VIII element and the Sn element;
c. After drying and calcining, adding an alkali metal compound;
d. calcination, reduction treatment to cause the alkali metal to be present in the form of an oxide and the supported metal to be present in the form of a VIII ₃ Sn intermetallic compound;
A process wherein the sulfur or sulfur compound is present in the aluminum source or is added to the alumina support during or after manufacture of the alumina support. 8. Process according to claim 7, wherein the aluminum source is one or more selected from pseudo-boehmite, boehmite, aluminum hydroxide, preferably pseudo-boehmite. 9. The method according to claim 7 or 8, wherein the sulfur or sulfur compound is one or more selected from sulfur powder, sulfuric acid, sulfate. Claim 7, wherein the metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex, or mixture thereof of the Group VIII element is used as a raw material, and the Group VIII element is supported by ion exchange, impregnation or precipitation. 10. The method according to any one of items 1 to 9. Any one of claims 7 to 10, wherein the Sn element is supported by sequential impregnation or co-impregnation using a Sn element metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex, or a mixture thereof as a raw material. 1. The method according to item 1. 12. The method according to any one of claims 7 to 11, wherein the molar ratio n _VIII :n _Sn of group VIII elements to Sn elements in step b is between 2 and 4, preferably between 2.5 and 3.5. described method. Claims 7 to 12, wherein the metal acid, metal acid salt, chloride, ammonia complex, carbonyl complex, or mixture thereof of an alkali metal element is used as a raw material, and an alkali metal element is supported by ion exchange, impregnation, or precipitation. A method according to any one of 14. Any one of claims 7 to 13, wherein after supporting the Group VIII element and the Sn element, it is dried, left to stand and then calcined, and the calcination temperature is 300 to 750° C. and the calcination time is 1 to 12 hours. The method described in . 15. The catalyst according to any one of claims 7 to 14, wherein the catalyst is reduced with a reducing agent, such as hydrogen gas, before use, the reduction temperature is 350-800° C., and the reduction time is 0.5-24 hours. described method. Use of the catalyst according to any one of claims 1-6 in cycloalkane dehydrogenation.

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