Dehydrogenation catalyst, method for preparing and using the same, and method for dehydrogenating methylcyclohexane

Abstract

The application discloses a dehydrogenation catalyst, application and preparation method thereof. The catalyst contains a carrier and a metal component, the metal component contains Pt and optionally other auxiliary metals, wherein the dispersion degree of Pt element in the catalyst is 55%-75%. The application provides a methylcyclohexane dehydrogenation method, which is carried out in the presence of the dehydrogenation catalyst. The dehydrogenation catalyst has not only low platinum loading, but also high dispersion degree of Pt element on the surface of the carrier, and has very high catalytic activity area. The dehydrogenation catalyst is used for alkane dehydrogenation (such as methylcyclohexane dehydrogenation), and under the condition of low reaction temperature, the alkane conversion rate is high, for example, the methylcyclohexane dehydrogenation, and the methylcyclohexane conversion rate is as high as 92%-95%.

Description

Technical Field

[0001] This invention relates to a dehydrogenation catalyst, its preparation method and application, and a method for dehydrogenating methylcyclohexane. Background Technology

[0002] With socio-economic development, human demand for energy continues to grow, leading to increasingly severe environmental problems such as increased carbon emissions and the greenhouse effect. Organic liquid hydrogen storage technology can achieve stable storage and transportation of hydrogen at ambient temperature and pressure, and is compatible with mature petroleum industry infrastructure and storage and distribution equipment, making it one of the most promising new hydrogen storage technologies currently available.

[0003] Methylcyclohexane is a bulk chemical with a hydrogen storage density of 6.1 wt% by mass and 47 kg / m³ by volume. 3 Furthermore, the main dehydrogenation products of methylcyclohexane are toluene and hydrogen, with few byproducts, reducing the difficulty of hydrogen separation and purification. Therefore, methylcyclohexane is considered a suitable organic carrier for large-scale hydrogen storage and transportation. According to existing research, platinum is the most effective catalyst for the dehydrogenation of methylcyclohexane; however, the low abundance of platinum in the Earth's crust and its high market price have become bottlenecks for the widespread application of platinum-based catalysts. Improving the utilization rate of platinum atoms and maintaining high catalyst activity have become key technical challenges that platinum-based catalysts must overcome.

[0004] Science Advances, 2019, 5, 6322 discloses the use of sulfur-containing precursors to pre-modify the support, enhancing the interaction between the support and the metal precursor, and preparing a series of atomically dispersed noble metal catalysts, including Pt, Ir, Rh, Ru, and Pd. Nature Commun. 2020, 11, 1263 discloses that introducing elements such as Fe and Mg into the catalyst support can also improve the dispersion of supported noble metal nanoparticles. CN111111654A discloses a method for preparing an improved Pt / Mg-Al-O dehydrogenation catalyst, using a co-precipitation method to prepare Mg-modified alumina as a noble metal support. Experimental results show that the above technical solution can reduce the amount of noble metal used to a certain extent and improve the conversion rate of methylcyclohexane. However, the above preparation products or methods are not suitable for large-scale production and application of catalysts. The specific surface area, pore volume, and pore size of the modified supports prepared in the laboratory have poor reproducibility, resulting in poor stability of the prepared catalysts.

[0005] Therefore, there is an urgent need to develop a catalyst with high platinum atom utilization that is suitable for large-scale industrial applications and can be used in the catalytic dehydrogenation reaction of methylcyclohexane. Summary of the Invention

[0006] The purpose of this invention is to improve the utilization rate of platinum atoms in the catalyst, and to overcome the problem that high-activity catalysts cannot be prepared uniformly on a large scale in the prior art. This invention provides a dehydrogenation catalyst, its preparation method and application, and a method for dehydrogenating methylcyclohexane. The dehydrogenation catalyst has high Pt element dispersion. When used for the dehydrogenation of methylcyclohexane, the conversion rate of methylcyclohexane is as high as 92%-95% at a relatively low reaction temperature.

[0007] To achieve the above objectives, the first aspect of the present invention provides a dehydrogenation catalyst comprising a support and a metal component, wherein the metal component comprises Pt and optionally other auxiliary metals, wherein the dispersion of Pt element in the catalyst is 55%-75%.

[0008] A second aspect of the present invention provides the application of the dehydrogenation catalyst described herein in the dehydrogenation of alkane.

[0009] A third aspect of the present invention provides a method for preparing the dehydrogenation catalyst of the present invention, the method comprising: loading a metal component Pt and optionally a co-metal component onto the support, and performing reduction using a reducing gas containing hydrogen sulfide and hydrogen, wherein the hydrogen sulfide content in the reducing gas is 0-2 ppm and is not 0.

[0010] A fourth aspect of the present invention provides a method for dehydrogenating methylcyclohexane, wherein methylcyclohexane is dehydrogenated in the presence of the dehydrogenation catalyst described in the present invention.

[0011] Through the above technical solution, the dehydrogenation catalyst of the present invention not only has a low platinum loading, but also a high degree of Pt element dispersion on the support surface, resulting in a very high catalytically active surface area. This dehydrogenation catalyst is used for alkane dehydrogenation (e.g., methylcyclohexane dehydrogenation), achieving high alkane conversion rates at relatively low reaction temperatures; for example, in the dehydrogenation of methylcyclohexane, the methylcyclohexane conversion rate is as high as 92%-95%.

[0012] In the field, hydrogen sulfide is generally considered a poison for noble metal catalysts. This invention creatively discovers and utilizes hydrogen sulfide to reduce catalysts and improve the dispersion of noble metal catalysts. Attached Figure Description

[0013] Figure 1 These are the hydrogen-oxygen titration curves of Examples 1, 2, 3 and Comparative Example 1. Detailed Implementation

[0014] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0015] According to a first aspect of the present invention, a dehydrogenation catalyst is provided, the catalyst comprising a support and a metal component, said metal component comprising Pt and optionally other auxiliary metals, wherein the dispersion of Pt in the catalyst is 55%-75%. The dehydrogenation catalyst of the present invention achieves higher dispersion on the catalyst surface, reduces the amount of Pt used in the prior art, and improves the dispersion of Pt, thus possessing a very high catalytic active area.

[0016] In this invention, there are no special requirements for the type of auxiliary metal. Any auxiliary metal conventional in the art can be used in this invention. According to a preferred embodiment of this invention, the auxiliary metal is selected from at least one of Fe, Co, Ni, Sn, In, Zn, Cu and Mn, and preferably selected from at least one of Fe, Co, Zn, Sn and Cu.

[0017] According to a preferred embodiment of the present invention, based on the total mass of the catalyst, the content of the auxiliary metal element is 0.05%-0.3% and the content of Pt element is 0.3%-0.9%.

[0018] The present invention does not have any special requirements for the type of carrier. Common carriers can be used in the present invention. For the present invention, the carrier is preferably selected from one or more of alumina, graphite, silicon oxide, and spinel, and more preferably selected from alumina.

[0019] According to a second aspect of the present invention, the present invention provides the application of the catalyst of the present invention in the dehydrogenation of alkanes, preferably C5-C10 alkanes, more preferably methylcyclohexane. The dehydrogenation catalyst of the present invention, when used for the dehydrogenation of alkanes, exhibits high alkane conversion rates at relatively low reaction temperatures, especially for the dehydrogenation of C5-C10 alkanes, for example, for the dehydrogenation of methylcyclohexane, where the methylcyclohexane conversion rate reaches as high as 92%-95%.

[0020] In this invention, the objective of the invention can be achieved as long as the catalyst possesses the characteristics described herein. There are no particular requirements for the preparation method of the catalyst. Preferably, the preparation method of the dehydrogenation catalyst includes: loading a metal component Pt and optionally a co-metal component onto the support; and reducing the catalyst using a reducing gas containing hydrogen sulfide and hydrogen, wherein the hydrogen sulfide content in the reducing gas is 0-2 ppm and not zero. This invention creatively utilizes hydrogen sulfide to reduce the catalyst, thereby improving the dispersion of the noble metal catalyst.

[0021] According to a preferred embodiment of the present invention, the hydrogen sulfide content in the reducing gas is 0.1-2 ppm. This is beneficial for improving the dispersion of the noble metal catalyst.

[0022] In this invention, the reduction conditions are not particularly limited. According to a preferred embodiment of the invention, the reduction conditions include a temperature of 300-450°C and a time of 4-8 hours. This is beneficial for improving the dispersion of the noble metal catalyst.

[0023] According to a preferred embodiment of the present invention, the reduction conditions further include: the flow rate of the reducing gas is controlled at 100-300 ml / min.

[0024] In this invention, it is sufficient to load the metal component Pt and optionally the co-metal component onto the support; the loading method is not particularly limited. According to a preferred embodiment of the present invention, the preparation method of the catalyst includes:

[0025] (1) The dispersions of Pt source and optional auxiliary metal source are adsorbed onto the support by an equal volume impregnation method and dried to obtain the catalyst precursor.

[0026] (2) The catalyst precursor is calcined;

[0027] (3) The roasting product obtained in step (2) is reduced by a reducing gas containing hydrogen sulfide and hydrogen.

[0028] In this invention, there are no special requirements for the types of Pt source and auxiliary metal source. Commonly used Pt sources and auxiliary metal sources in the art can be used in this invention. Preferably, for this invention, the Pt source and auxiliary metal source are each selected from corresponding water-soluble metal salts and / or acids.

[0029] According to a preferred embodiment of the present invention, the Pt source is selected from at least one of chloroplatinic acid, sodium chloroplatinate, dichlorotetraaminoplatinum, and tetraammineplatinum nitrate.

[0030] According to a preferred embodiment of the present invention, the auxiliary metal source is selected from at least one of hydrochloride, nitrate and acetate.

[0031] In this invention, the pH value of the dispersion can be selected within a wide range. According to a preferred embodiment of the invention, the pH value of the dispersion containing the Pt source and optionally a cofactor metal source is controlled between 3.5 and 5. In this invention, it is preferable to adjust the pH value by adding acid during the loading stage to achieve preliminary control of the dispersion state of the Pt precursor on the support. Combined with subsequent reduction, this can significantly improve the catalyst activity and stability of the present invention. This invention does not have special requirements for the type of acid. For this invention, it is preferred that the acid is one or more of hydrochloric acid, acetic acid, perchloric acid, and nitric acid.

[0032] In this invention, there are no special requirements for the roasting conditions. According to a preferred embodiment of the invention, the roasting conditions include: a temperature of 400-600℃; the roasting time can be reasonably adjusted according to the roasting temperature, preferably 3-6h, and preferably, the heating rate is 1-5℃ / min.

[0033] According to a fourth aspect of the present invention, a method for dehydrogenating methylcyclohexane is provided, wherein methylcyclohexane is dehydrogenated in the presence of the dehydrogenation catalyst described herein. The dehydrogenation catalyst described herein is used for the dehydrogenation of methylcyclohexane, achieving a methylcyclohexane conversion rate as high as 92%-95%.

[0034] In this invention, there are no particular limitations on the dehydrogenation conditions. Conventional dehydrogenation conditions in the art are applicable in the presence of the dehydrogenation catalyst described in this invention. According to this invention, preferably, the dehydrogenation conditions include: reacting the catalyst and methylcyclohexane in an inert atmosphere at a reaction temperature of 300-400°C, and a mass hourly space velocity (WHSV) of methylcyclohexane of 1-10 h⁻¹. -1 .

[0035] According to a preferred embodiment of the present invention, the inert atmosphere is a nitrogen atmosphere.

[0036] According to a preferred embodiment of the present invention, the catalyst and methylcyclohexane are reacted in a nitrogen atmosphere, the catalyst loading is 1 g, the reaction temperature is 340 °C, and the mass hourly space velocity (WHSV) of methylcyclohexane is 2 h⁻¹. -1 .

[0037] In this invention, the dispersibility test method is a hydrogen-oxygen titration test, and the specific test steps are as follows: Using a Micromeritics Inc. (AutoChem II 2920) instrument, the temperature is increased to 350°C at a rate of 10°C / min, and reduction is performed using H₂ / Ar for 2 hours, with a hydrogen volume concentration of 10%. The atmosphere is then switched to Ar, purged for 1 hour, and cooled to 45°C. An oxygen-argon mixture containing 10% oxygen is introduced and maintained for 60 minutes. A hydrogen-argon mixture containing 10% hydrogen is titrated using a loop injection method with 15 pulses. This oxygen-argon and hydrogen-argon cycle is repeated three times to obtain the hydrogen-oxygen titration curve. The amount of hydrogen titrated in the hydrogen-oxygen titration is calculated as V by curve integration. H (mL). V 标 The concentration is 22.4 L / mol, M is the atomic weight of Pt 195 (g / mol), m is the catalyst mass (g), and W% is the Pt loading.

[0038] In this invention, the elemental content in the catalyst is analyzed by ICP.

[0039] The present invention will be described in detail below through embodiments.

[0040] In this invention, there are no special requirements for the alumina support source; any commonly used alumina support source can be used. In the embodiments, γ-alumina is used as the alumina support.

[0041] Example 1

[0042] (1) Prepare an aqueous solution of chloroplatinic acid and ferric chloride with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 10 mg / mL. Add an appropriate amount of hydrochloric acid to adjust the pH to 4. Load the metal ions onto the surface of the alumina support by impregnation with an equal volume. Then treat at 110℃ for 2 hours to obtain the catalyst precursor.

[0043] (2) The catalyst precursor was calcined in an air atmosphere at 550°C for 4 hours, and the heating rate of the calcination furnace was 5°C / min.

[0044] (3) Take 5g of the roasted product and place it in a tubular reactor for reduction. The reduction temperature is 350℃ and the reduction time is 4h. The reducing gas is a mixture of hydrogen and hydrogen sulfide, with the concentration of hydrogen sulfide being 0.5ppm and the flow rate of the reducing gas being 100ml / min.

[0045] The Pt content, Fe element content, and platinum element dispersion of the catalyst are shown in Table 1.

[0046] Dehydrogenation of methylcyclohexane to produce hydrogen:

[0047] In a reaction tube, the catalyst and methylcyclohexane were reacted under a nitrogen atmosphere. The catalyst loading was 1 g, the reaction temperature was 340 °C, and the mass hourly space velocity (WHSV) of methylcyclohexane was 2 h⁻¹. -1 The product after 12 hours of reaction was analyzed, and the conversion rate of methylcyclohexane was 93%, while the selectivity of toluene was 99%.

[0048] Example 2

[0049] (1) Prepare an aqueous solution of chloroplatinic acid and ferric chloride with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 10 mg / mL. Add an appropriate amount of acetic acid to adjust the pH to 3.5. Load the metal ions onto the surface of the alumina support by impregnation with an equal volume. Then treat at 110℃ for 2 hours to obtain the catalyst precursor.

[0050] (2) The catalyst precursor was calcined in an air atmosphere at 550°C for 4 hours, and the heating rate of the calcination furnace was 5°C / min.

[0051] (3) Take 5g of the roasted product and place it in a tubular reactor for reduction. The reduction temperature is 350℃ and the reduction time is 4h. The reducing gas is a mixture of hydrogen and hydrogen sulfide, with the concentration of hydrogen sulfide being 1ppm and the flow rate of the reducing gas being 300ml / min.

[0052] The Pt content, Fe element content, and platinum element dispersion of the catalyst are shown in Table 1.

[0053] The dehydrogenation of methylcyclohexane to produce hydrogen was carried out according to the method of Example 1. The conversion rate of methylcyclohexane and the selectivity of toluene are listed in Table 1.

[0054] Example 3

[0055] (1) Prepare an aqueous solution of chloroplatinic acid and ferric chloride with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 10 mg / mL. Add an appropriate amount of nitric acid to make the pH value 5. Load the metal ions onto the surface of the alumina support by impregnation with an equal volume. Then treat at 110℃ for 2 hours to obtain the catalyst precursor;

[0056] (2) The catalyst precursor was calcined in an air atmosphere at 550°C for 4 hours, and the heating rate of the calcination furnace was 5°C / min.

[0057] (3) Take 5g of the roasted product and place it in a tubular reactor for reduction. The reduction temperature is 350℃ and the reduction time is 4h. The reducing gas is a mixture of hydrogen and hydrogen sulfide, with the concentration of hydrogen sulfide being 0.1ppm and the flow rate of the reducing gas being 100ml / min.

[0058] The Pt content, Fe element content, and platinum element dispersion of the catalyst are shown in Table 1.

[0059] The dehydrogenation of methylcyclohexane to produce hydrogen was carried out according to the method of Example 1. The conversion rate of methylcyclohexane and the selectivity of toluene are listed in Table 1.

[0060] Example 4

[0061] (1) Prepare an aqueous solution of chloroplatinic acid and ferric chloride with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 10 mg / mL. Add an appropriate amount of perchloric acid to make the pH value 5. Load the metal ions onto the surface of the alumina support by impregnation with an equal volume. Then treat at 110℃ for 2 hours to obtain the catalyst precursor;

[0062] (2) The catalyst precursor was calcined in an air atmosphere at 550°C for 4 hours, and the heating rate of the calcination furnace was 5°C / min.

[0063] (3) Take 5g of the roasted product and place it in a tubular reactor for reduction. The reduction temperature is 350℃ and the reduction time is 4h. The reducing gas is a mixture of hydrogen and hydrogen sulfide, with the concentration of hydrogen sulfide being 2ppm and the flow rate of the reducing gas being 250ml / min.

[0064] The Pt content, Fe element content, and platinum element dispersion of the catalyst are shown in Table 1.

[0065] The dehydrogenation of methylcyclohexane to produce hydrogen was carried out according to the method of Example 1. The conversion rate of methylcyclohexane and the selectivity of toluene are listed in Table 1.

[0066] Example 5

[0067] (1) Prepare an aqueous solution of chloroplatinic acid and copper chloride with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 12 mg / mL. Add an appropriate amount of hydrochloric acid to make the pH value 4.5. Load the metal ions onto the surface of the alumina support by impregnation with an equal volume. Then treat at 110℃ for 2 hours to obtain the catalyst precursor.

[0068] (2) The catalyst precursor was calcined in an air atmosphere at 550°C for 4 hours, and the heating rate of the calcination furnace was 5°C / min.

[0069] (3) Take 5g of the roasted product and place it in a tubular reactor for reduction. The reduction temperature is 350℃ and the reduction time is 4h. The reducing gas is a mixture of hydrogen and hydrogen sulfide, with the concentration of hydrogen sulfide being 1.5ppm and the flow rate of the reducing gas being 200ml / min.

[0070] The Pt content, Cu content, and platinum dispersion of the catalyst are shown in Table 1.

[0071] The dehydrogenation of methylcyclohexane to produce hydrogen was carried out according to the method of Example 1. The conversion rate of methylcyclohexane and the selectivity of toluene are listed in Table 1.

[0072] Example 6

[0073] (1) Prepare aqueous solutions of chloroplatinic acid and tin chloride with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 15 mg / mL. Add an appropriate amount of hydrochloric acid to make the pH value 3.5. Load the metal ions onto the surface of the alumina support by impregnation with an equal volume. Then treat at 110℃ for 2 hours to obtain the catalyst precursor.

[0074] (2) The catalyst precursor was calcined in an air atmosphere at 550°C for 4 hours, and the heating rate of the calcination furnace was 5°C / min.

[0075] (3) Take 5g of the roasted product and place it in a tubular reactor for reduction. The reduction temperature is 350℃ and the reduction time is 4h. The reducing gas is a mixture of hydrogen and hydrogen sulfide, with the concentration of hydrogen sulfide being 1.3ppm and the flow rate of the reducing gas being 250ml / min.

[0076] The Pt content, Sn content, and platinum dispersion of the catalyst are shown in Table 1.

[0077] The dehydrogenation of methylcyclohexane to produce hydrogen was carried out according to the method of Example 1. The conversion rate of methylcyclohexane and the selectivity of toluene are listed in Table 1.

[0078] Example 7

[0079] The method is the same as in Example 1, except that the carrier used is silicon dioxide, while the other conditions remain unchanged.

[0080] Example 8

[0081] The method is the same as in Example 1, except that...

[0082] Prepare an aqueous solution of chloroplatinic acid and ferric chloride with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 10 mg / mL, and a pH of 6.

[0083] Example 9

[0084] The method is the same as in Example 1, except that...

[0085] Prepare an aqueous solution of chloroplatinic acid and ferric chloride with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 10 mg / mL, and a pH of 3.

[0086] Example 10

[0087] The method is the same as in Example 1, except that...

[0088] Prepare an aqueous solution of chloroplatinic acid and ferric chloride with a platinum ion concentration of 75 mg / mL and an iron ion concentration of 15 mg / mL.

[0089] Example 11

[0090] The method is the same as in Example 1, except that...

[0091] Prepare an aqueous solution of chloroplatinic acid and ferric chloride with a platinum ion concentration of 20 mg / mL and an iron ion concentration of 1 mg / mL.

[0092] Comparative Example 1

[0093] (1) Chloroplatinic acid and ferric chloride were prepared into an aqueous solution with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 10 mg / mL, and a pH of 4. Metal ions were loaded onto the surface of an alumina support by equal-volume impregnation. Subsequently, the solution was treated at 110℃ for 2 hours to obtain the catalyst precursor.

[0094] (2) The catalyst precursor was calcined in an air atmosphere at 550°C for 4 hours, and the heating rate of the calcination furnace was 5°C / min.

[0095] (3) Take 5g of the roasted product and place it in a tubular reactor for reduction. The reduction temperature is 350℃, the reduction time is 4h, the reducing gas is hydrogen, and the reducing gas flow rate is 200ml / min.

[0096] The Pt content, Fe element content, and platinum element dispersion of the catalyst are shown in Table 1.

[0097] The dehydrogenation of methylcyclohexane to produce hydrogen was carried out according to the method of Example 1. The conversion rate of methylcyclohexane and the selectivity of toluene are listed in Table 1.

[0098] Comparative Example 2

[0099] (1) Chloroplatinic acid and ferric chloride were prepared into an aqueous solution with a platinum ion concentration of 50 mg / mL and an iron ion concentration of 10 mg / mL, and a pH of 3.7. Metal ions were loaded onto the surface of an alumina support by equal-volume impregnation. Subsequently, the solution was treated at 110℃ for 2 hours to obtain the catalyst precursor.

[0100] (2) The catalyst precursor was calcined in an air atmosphere at 550°C for 4 hours, and the heating rate of the calcination furnace was 5°C / min.

[0101] (3) Take 5g of the roasted product and place it in a tubular reactor for reduction. The reduction temperature is 350℃ and the reduction time is 4h. The reducing gas is a mixture of hydrogen and hydrogen sulfide, with the concentration of hydrogen sulfide being 3ppm and the flow rate of the reducing gas being 250ml / min.

[0102] The Pt content, Fe element content, and platinum element dispersion of the catalyst are shown in Table 1.

[0103] The dehydrogenation of methylcyclohexane to produce hydrogen was carried out according to the method of Example 1. The conversion rate of methylcyclohexane and the selectivity of toluene are listed in Table 1.

[0104] Figure 1These are the hydrogen-oxygen titration curves for Examples 1, 2, 3, and Comparative Example 1. Based on the hydrogen-oxygen titration results, the dispersion of platinum in each sample can be calculated. The calculation results show that introducing a certain amount of hydrogen sulfide during the catalyst reduction process can effectively improve the dispersion of noble metals in the catalyst and enhance the catalytic activity of the catalyst in the dehydrogenation reaction.

[0105] Table 1

[0106]

[0107] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A dehydrogenation catalyst, characterized in that, The catalyst contains a support and a metal component, wherein the metal component contains Pt and other auxiliary metals, and the Pt element dispersion in the catalyst is 55%-75%; The auxiliary metal is selected from at least one of Fe, Co, Ni, In, Zn, Cu and Mn; Based on the total mass of the catalyst, the content of the auxiliary metal element is 0.05%-0.3%; the content of Pt element is 0.3%-0.9%. The preparation method of the dehydrogenation catalyst includes: (1) The dispersions of Pt source and auxiliary metal source were adsorbed onto the support by an equal volume impregnation method and dried to obtain the catalyst precursor; (2) The catalyst precursor is calcined; (3) The calcined product obtained in step (2) is reduced by a reducing gas containing hydrogen sulfide and hydrogen; The pH of the dispersion containing the Pt source and the auxiliary metal source is controlled at 3.5-5; the pH is adjusted by adding acid, wherein the acid is one or more of hydrochloric acid, perchloric acid and nitric acid; The hydrogen sulfide content in the reducing gas is 0.1-2 ppm.

2. The catalyst according to claim 1, wherein, The auxiliary metal is selected from at least one of Fe, Co, Zn and Cu.

3. The catalyst according to claim 1, wherein, The carrier is selected from one or more of alumina, graphite, silicon dioxide, and spinel.

4. The catalyst according to claim 3, wherein, The carrier is aluminum oxide.

5. The catalyst according to claim 1, wherein, The reduction conditions include: a temperature of 300-450℃ and a time of 4-8 hours; and / or The flow rate of the reducing gas is controlled at 100-300 ml / min.

6. The catalyst according to claim 1, wherein, The Pt source and the auxiliary metal source are each selected from the corresponding water-soluble metal salts and / or acids.

7. The catalyst according to claim 6, wherein, The Pt source is selected from at least one of chloroplatinic acid, sodium chloroplatinate, dichlorotetraaminoplatinum, and tetraammineplatinum nitrate. The auxiliary metal source is selected from at least one of hydrochloride, nitrate and acetate.

8. The catalyst according to claim 1, wherein, The calcination conditions in step (2) include: a temperature of 400-600℃, a calcination time of 3-6h, and a heating rate of 1-5℃ / min.

9. The use of the catalyst according to any one of claims 1-8 in the dehydrogenation of alkane.

10. The application according to claim 9, wherein, The alkane is a C5-C10 alkane.

11. The application according to claim 10, wherein, The alkane is methylcyclohexane.

12. A method for dehydrogenating methylcyclohexane, characterized in that, Methylcyclohexane is dehydrogenated in the presence of the dehydrogenation catalyst according to any one of claims 1-8.

13. The method according to claim 12, wherein, The dehydrogenation conditions include: reacting the catalyst and methylcyclohexane in an inert atmosphere at a temperature of 300-400℃, with a mass hourly space velocity (WHSV) of methylcyclohexane of 1-10 h⁻¹. -1 .

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