Catalyst, preparation method and application thereof, and cyclohexane compound dehydrogenation method

Abstract

The invention relates to the field of catalysts, in particular to a catalyst, a preparation method and application thereof and a cyclohexane compound dehydrogenation method. The catalyst comprises a carrier, metal Pt and alkaline metal, the particle size of the metal Pt in the catalyst is 1.2-2.5 nm, and the total acid content of the catalyst is 150-350 [mu] mol NH3 / g. The particle size of the metal platinum in the catalyst is 1.2-2.5 nanometers, and the total acid content of the catalyst is 150-350 [mu] mol NH3 / g, so that the catalyst has excellent stability and catalytic hydrogenation activity.

Description

Technical Field

[0001] The invention relates to the field of catalysts, and in particular to a catalyst and a preparation method and application thereof, and a method for dehydrogenating cyclohexane compounds. Background Art

[0002] Hydrogen energy is a secondary energy source with a wide range of sources, clean and carbon-free, and rich application scenarios. It is the cleanest energy with the greatest development potential. In view of the outstanding advantages of hydrogen energy and its important significance to energy transformation, many countries have elevated the development of hydrogen energy to the level of national energy strategy for deployment. Reducing fossil fuels and increasing the proportion of clean energy use has become a global trend. The number of countries that have formulated and implemented hydrogen energy strategies has increased from 13 in 2020 to nearly 50 in 2022.

[0003] At present, the bottleneck of large-scale application of hydrogen lies in the efficient and safe storage and transportation of hydrogen energy. In recent years, hydrogen storage technology has developed rapidly, and organic liquid hydrogen storage technology has attracted widespread attention due to its advantages such as high hydrogen storage density and safe transportation of hydrogen storage liquid. Among them, the methylcyclohexane-toluene system is the liquid hydrogen storage system with the most promising industrial application prospects. In 2019, based on the methylcyclohexane-toluene system, Chiyoda Corporation realized the ocean import of hydrogen for the first time, with an annual supply scale of 210 tons.

[0004] The operational stability of the dehydrogenation catalyst is a very critical performance parameter for industrial catalysts. In addition to toluene, the dehydrogenation product of methylcyclohexane also generates byproducts such as cyclopentene and cyclohexene. The deep coupling reaction of toluene and the above byproducts will form carbon deposits on the catalyst surface, resulting in reduced catalyst activity. Nakaya et al. (ACS Catalysis, 2020, 10, 5163-5172) introduced transition metal elements to form alloys with platinum, weakened the adsorption of the catalyst to the product, avoided the occurrence of deep coupling reactions, and improved the stability of the catalyst. CN102068990B discloses a dehydrogenation catalyst preparation process based on a nano-carbon-coated alumina carrier, and the results show that the catalyst's resistance to carbon deposition has been significantly improved. CN106622228A regulates the acidity of the entire catalyst and improves the activity and stability of the catalyst by introducing alkaline metals in the carrier preparation stage. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems of poor catalyst stability and low activity in the prior art, and to provide a catalyst and a preparation method and application thereof and a method for dehydrogenating cyclohexane compounds. The catalyst has high stability and catalytic dehydrogenation activity.

[0006] In order to achieve the above object, the first aspect of the present invention provides a catalyst, which comprises a carrier, metal Pt and an alkaline metal; the particle size of the metal Pt in the catalyst is 1.2-2.5 nm, and the total acid content of the catalyst is 150-350 μmol NH3 / g.

[0007] The second aspect of the present invention provides a method for preparing the catalyst described in the first aspect, which comprises: (a) subjecting a catalyst carrier to a first contact with an impregnation solution containing an alkaline metal, a first drying, and a first calcination to obtain a precursor; (b) subjecting the precursor to a second contact with an impregnation solution containing metal platinum, a second drying, a second calcination, and optionally a reduction; the conditions for the first contact comprise: the volume of the catalyst carrier: the volume of the impregnation solution containing the alkaline metal = 1:1.05-1.2, and the contact temperature is 20-40°C; the first calcination is carried out in an inert atmosphere; the conditions for the second contact comprise: the volume of the precursor: the volume of the impregnation solution containing the metal platinum = 1.2-1.5, and the contact temperature is 50-80°C; and the second calcination is carried out in an oxidizing atmosphere with an oxygen content of 5-15vol%.

[0008] The third aspect of the present invention provides an application of the catalyst described in the first aspect in a dehydrogenation reaction, preferably in the dehydrogenation of cyclohexane compounds.

[0009] A fourth aspect of the present invention provides a method for dehydrogenating cyclohexane compounds, characterized in that the method comprises: under the catalyst conditions described in the first aspect, contacting and reacting the cyclohexane compound raw material with hydrogen.

[0010] Through the above technical solution, the present invention has the following beneficial effects:

[0011] The particle size of the metal platinum in the catalyst of the present invention is 1.2-2.5 nanometers, and the total acid content of the catalyst is 150-350 μmol NH3 / g, so that the catalyst has excellent stability and catalytic hydrogenation activity.

[0012] In the preparation method of the present invention, by controlling the loading mode of the noble metal component and the alkaline metal component, the particle size of the metal platinum in the prepared catalyst can be made 1.2-2.5 nanometers, and the total acid content of the catalyst can be 150-350 μmol NH3 / g.

[0013] The catalyst of the present invention is particularly suitable for the dehydrogenation of cyclohexane compounds and has high dehydrogenation efficiency and catalyst stability during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a transmission electron microscope image of the catalyst of Example 1;

[0015] Figure 2 This is a transmission electron microscope image of the catalyst of Comparative Example 3. DETAILED DESCRIPTION

[0016] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0017] The invention provides a catalyst, which comprises a carrier, metal Pt and an alkaline metal; the particle size of the metal Pt in the catalyst is 1.2-2.5 nm, and the total acid content of the catalyst is 150-350 μmol NH3 / g.

[0018] The particle size of the metal platinum in the catalyst of the present invention is 1.2-2.5 nanometers, and the total acid content of the catalyst is 150-350 μmol NH3 / g, so that the catalyst has excellent stability and catalytic hydrogenation activity.

[0019] According to a preferred embodiment of the present invention, the particle size of the metal Pt in the catalyst is 1.22-2.13 nm.

[0020] According to a preferred embodiment of the present invention, the total acid content of the catalyst is 170-330 μmol NH3 / g.

[0021] According to a preferred embodiment of the present invention, the weight ratio of the alkaline metal to Pt in the catalyst is 0.01-30.

[0022] According to a preferred embodiment of the present invention, based on the total mass of the catalyst, the Pt content in the catalyst is 0.1-1.2wt%, preferably 0.2-1wt%. The alkaline metal content is 0.01-3wt%, preferably 0.1-3wt%; and the carrier content is 95.8-99.89wt%, preferably 96-99.7wt%.

[0023] According to a preferred embodiment of the present invention, the carrier is selected from alumina and / or titanium oxide, preferably alumina.

[0024] According to a preferred embodiment of the present invention, the alkaline metal is an alkali metal and / or an alkaline earth metal, preferably at least one of potassium, calcium, sodium, magnesium, cesium, rubidium, and lithium, preferably at least one of potassium, calcium, and magnesium.

[0025] The present invention provides a method for preparing the catalyst, which comprises:

[0026] (a) subjecting a catalyst support to a first contact with an impregnation solution containing an alkaline metal, a first drying, and a first calcination to obtain a precursor;

[0027] (b) the precursor is contacted with an impregnation solution containing metal platinum for a second time, dried for a second time, calcined for a second time, and optionally reduced;

[0028] The conditions of the first contact include: the volume of the catalyst support: the volume of the impregnation solution containing the alkaline metal dissolved therein = 1: 1.05-1.2, and the contact temperature is 20-40° C.;

[0029] The first calcination is carried out in an inert atmosphere;

[0030] The conditions of the second contact include: precursor volume: impregnation solution volume containing metal platinum = 1.2-1.5, contact temperature 50° C.-80° C.;

[0031] The second calcination is performed in an oxidative atmosphere with an oxygen content of 5-15 vol%.

[0032] In the preparation method of the present invention, by controlling the loading mode of the noble metal component and the alkaline metal component, the particle size of the metal platinum in the prepared catalyst can be made 1.2-2.5 nanometers, and the total acid content of the catalyst can be 150-350 μmol NH3 / g.

[0033] According to a preferred embodiment of the present invention, the temperature of the second contacting is 10-60°C higher than the temperature of the first contacting, preferably 20-40°C higher.

[0034] In the present invention, the time of the first contact depends on the contact temperature. According to a preferred embodiment of the present invention, the time of the first contact is 4-8 hours.

[0035] In the present invention, the first contact time depends on the contact temperature. According to a preferred embodiment of the present invention, the first contact time is 0.5-2h.

[0036] According to a preferred embodiment of the present invention, the first calcination conditions include: calcination at 300-500° C. for 2-4 hours.

[0037] According to a preferred embodiment of the present invention, the second calcination conditions include: calcination at 450-550° C. for 1-3 hours.

[0038] According to a preferred embodiment of the present invention, the reduction conditions include: reduction at 350-450° C. for 4-8 hours.

[0039] In the present invention, there is no special requirement for the drying conditions. According to a preferred embodiment of the present invention, the first drying conditions include: drying at 80-120°C for 6-12h; the second drying conditions include: drying at 80-120°C for 6-12h.

[0040] In the present invention, there is no special requirement for the composition of the inert atmosphere, as long as it does not participate in the calcination reaction. According to a preferred embodiment of the present invention, the inert atmosphere is at least one of a nitrogen atmosphere, a helium atmosphere and an argon atmosphere.

[0041] The present invention provides an application of the catalyst in a dehydrogenation reaction, preferably in the dehydrogenation of cyclohexane compounds.

[0042] The catalyst of the present invention is particularly suitable for the dehydrogenation of cyclohexane compounds and has high dehydrogenation efficiency and catalyst stability during use.

[0043] The present invention provides a method for dehydrogenating cyclohexane compounds, which comprises: under the catalyst conditions, the cyclohexane compound raw material is contacted with hydrogen for reaction.

[0044] According to a preferred embodiment of the present invention, the cyclohexane compound is an alkylcyclohexane, preferably methylcyclohexane.

[0045] According to a preferred embodiment of the present invention, the conditions of the contact reaction include: the reaction temperature is 350-500°C.

[0046] According to a preferred embodiment of the present invention, the contact reaction conditions include: the mass space velocity of the alkyl cyclohexane is 1-10h -1 .

[0047] The present invention will be described in detail below through examples. In the following examples, the alkaline metal elements and platinum content in the catalyst are determined by ICP testing; the acid content of the catalyst is tested using NH3-TPD, and the sample is first desorbed at 550°C for 2h in an argon atmosphere, then cooled to below 60°C and adsorbed with ammonia for 0.5h. The atmosphere is then switched to argon, and the temperature is gradually raised to 640°C, and the amount of ammonia desorption is counted; the size of the catalyst nanoparticles is standardized using a transmission electron microscope; unless otherwise specified, the raw materials are all commercially available.

[0048] Example 1

[0049] The alumina carrier was placed in an aqueous solution with a potassium chloride concentration of 10 mg / mL, the volume of alumina: the volume of potassium chloride aqueous solution = 1:1.1, and it was allowed to stand at 30°C for 8 hours. The carrier A adsorbed with potassium chloride was obtained by filtration. The carrier A was dried at 100°C for 8 hours. The carrier A was then dried and calcined at 350°C for 2 hours in a nitrogen atmosphere to obtain the carrier B. The carrier B was contacted with an aqueous solution with a concentration of 30 mg / mL of chloroplatinic acid, the volume of the carrier B: the volume ratio of the chloroplatinic acid aqueous solution = 1:1.3, the contact temperature was 50°C, and the contact time was 2 hours. The catalyst precursor C was then obtained by filtration and drying at 100°C for 7 hours. The catalyst precursor C was calcined at 500°C in a nitrogen atmosphere with an oxygen content of 10 vol% for 4 hours, and then reduced in a hydrogen atmosphere at 350°C for 6 hours to obtain the desired catalyst.

[0050] ICP test was used to determine the content of alkaline metal elements and platinum elements in the catalyst; ammonia chemical adsorption was used to test the acid content of the catalyst; transmission electron microscopy was used to standardize the size of the catalyst nanoparticles. Figure 1 Transmission electron microscopy image of the catalyst of Example 1. The average size of the platinum nanoparticles in the catalyst can be known through particle statistics. The results are summarized in Table 1.

[0051] Dehydrogenation of methylcyclohexane to produce hydrogen:

[0052] In a reaction tube, the catalyst and methylcyclohexane were reacted in a hydrogen atmosphere. The catalyst loading was 1 g, the reaction temperature was 470 ° C, and the mass space velocity of methylcyclohexane was 4 h -1 The products of reaction time 2h and reaction time 100h were analyzed to calculate the conversion rate of methylcyclohexane. The results are summarized in Table 1.

[0053] Example 2

[0054] The alumina carrier was placed in an aqueous solution with a calcium nitrate concentration of 2 mg / mL, the volume of alumina: the volume of potassium chloride aqueous solution = 1:1.06, and it was allowed to stand at 40°C for 4 hours. The carrier A adsorbed with calcium nitrate was obtained by filtration. The carrier A was dried at 120°C for 6 hours. The carrier A was then dried and calcined at 300°C for 2 hours in a nitrogen atmosphere to obtain the carrier B. The carrier B was contacted with a 40 mg / mL aqueous solution of dichlorotetraaminoplatinum, the volume of the carrier B: the volume ratio of dichlorotetraaminoplatinum aqueous solution = 1:1.4, the contact temperature was 80°C, and the contact time was 0.5 hours. The catalyst precursor C was then obtained by filtration and drying at 120°C for 6 hours. The catalyst precursor C was calcined at 550°C in a nitrogen atmosphere with an oxygen content of 5 vol% for 2 hours, and then reduced in a hydrogen atmosphere at 400°C for 4 hours to obtain the desired catalyst.

[0055] ICP test was used to determine the content of alkaline metal elements and platinum elements in the catalyst; ammonia chemical adsorption was used to test the acid content of the catalyst; transmission electron microscopy was used to standardize the size of the catalyst nanoparticles. Figure 1 Similarly, the average size of the platinum nanoparticles in the catalyst can be determined by particle statistics, and the results are summarized in Table 1.

[0056] Dehydrogenation of methylcyclohexane to produce hydrogen:

[0057] In a reaction tube, the catalyst and methylcyclohexane were reacted in a hydrogen atmosphere. The catalyst loading was 1 g, the reaction temperature was 470 ° C, and the mass space velocity of methylcyclohexane was 4 h -1 The products of reaction time 2h and reaction time 100h were analyzed to calculate the conversion rate of methylcyclohexane. The results are summarized in Table 1.

[0058] Example 3

[0059] The alumina carrier was placed in an aqueous solution with a magnesium nitrate concentration of 15 mg / mL, the volume of alumina: the volume of the magnesium nitrate aqueous solution = 1:1.2, and the mixture was allowed to stand at 20°C for 6 hours. The carrier A adsorbed with magnesium nitrate was obtained by filtration. The carrier A was dried at 120°C for 6 hours. The carrier A was then dried and calcined at 500°C for 2 hours in an argon atmosphere to obtain the carrier B. The carrier B was contacted with a 30 mg / mL aqueous solution of tetraamine platinum nitrate, the volume of the carrier B: the volume ratio of the tetraamine platinum nitrate aqueous solution = 1:1.5, the contact temperature was 60°C, and the contact time was 1.5 hours. The catalyst precursor C was then obtained by filtration and drying at 120°C for 6 hours. The catalyst precursor C was calcined at 500°C in a nitrogen atmosphere with an oxygen content of 12 vol% for 2 hours, and then reduced in a hydrogen atmosphere at 450°C for 4 hours to obtain the desired catalyst.

[0060] ICP test was used to determine the content of alkaline metal elements and platinum elements in the catalyst; ammonia chemical adsorption was used to test the acid content of the catalyst; transmission electron microscopy was used to standardize the size of the catalyst nanoparticles. Figure 1 Similarly, the average size of the platinum nanoparticles in the catalyst can be determined by particle statistics, and the results are summarized in Table 1.

[0061] Dehydrogenation of methylcyclohexane to produce hydrogen:

[0062] In a reaction tube, the catalyst and methylcyclohexane were reacted in a hydrogen atmosphere. The catalyst loading was 1 g, the reaction temperature was 470 ° C, and the mass space velocity of methylcyclohexane was 4 h -1 The products of reaction time 2h and reaction time 100h were analyzed to calculate the conversion rate of methylcyclohexane. The results are summarized in Table 1.

[0063] Comparative Example 1

[0064] The alumina carrier was placed in an aqueous solution of 30 mg / mL chloroplatinic acid, with a volume ratio of alumina to chloroplatinic acid aqueous solution = 1:1.3. The system was heated to 50°C and allowed to stand for 2 hours. The catalyst precursor was then obtained by filtration and drying at 100°C for 7 hours. The catalyst precursor was calcined at 500°C in a nitrogen atmosphere with an oxygen content of 10 vol% for 4 hours, and then reduced in a hydrogen atmosphere at 350°C for 6 hours to obtain the desired catalyst.

[0065] ICP test was used to determine the content of alkaline metal elements and platinum elements in the catalyst; ammonia chemical adsorption was used to test the acid content of the catalyst; transmission electron microscopy was used to standardize the size of the catalyst nanoparticles. The transmission electron microscopy image of the catalyst is shown in the figure below. Figure 2 As shown, the average size of platinum nanoparticles in the catalyst can be known through particle statistics, and the results are summarized in Table 1.

[0066] Dehydrogenation of methylcyclohexane to produce hydrogen:

[0067] In a reaction tube, the catalyst and methylcyclohexane were reacted in a hydrogen atmosphere. The catalyst loading was 1 g, the reaction temperature was 470 ° C, and the mass space velocity of methylcyclohexane was 4 h -1 The products of reaction time 2h and reaction time 100h were analyzed to calculate the conversion rate of methylcyclohexane. The results are summarized in Table 1.

[0068] Comparative Example 2

[0069] The alumina carrier was placed in an aqueous solution with a concentration of 30 mg / mL of chloroplatinic acid, with a volume ratio of alumina to chloroplatinic acid aqueous solution = 1:1.3, and the system was heated to 50°C and allowed to stand for 2 hours. The carrier A was then obtained by filtration and drying at 100°C for 7 hours, and the carrier B was obtained by calcining the carrier A at 500°C in a nitrogen atmosphere with an oxygen content of 10 vol% for 4 hours. The carrier B was placed in an aqueous solution with a concentration of 10 mg / mL of potassium chloride, with a volume of alumina to a volume of potassium chloride aqueous solution = 1:1.1, and allowed to stand at 30°C for 8 hours, filtered, dried at 100°C for 8 hours, calcined at 350°C in a nitrogen atmosphere for 2 hours, and then reduced in a hydrogen atmosphere at 350°C for 6 hours to obtain the desired catalyst.

[0070] The ICP test was used to determine the alkaline metal elements and platinum content in the catalyst; the ammonia chemical adsorption was used to test the acid content of the catalyst; the size of the catalyst nanoparticles was standardized using a transmission electron microscope, and the average size of the platinum nanoparticles in the catalyst was determined by particle statistics. The results are summarized in Table 1.

[0071] Dehydrogenation of methylcyclohexane to produce hydrogen:

[0072] In a reaction tube, the catalyst and methylcyclohexane were reacted in a hydrogen atmosphere. The catalyst loading was 1 g, the reaction temperature was 470 ° C, and the mass space velocity of methylcyclohexane was 4 h -1 The products of reaction time 2h and reaction time 100h were analyzed to calculate the conversion rate of methylcyclohexane. The results are summarized in Table 1.

[0073] Comparative Example 3

[0074] The alumina carrier was placed in an aqueous solution with a potassium chloride concentration of 40 mg / mL, the volume of alumina: the volume of potassium chloride aqueous solution = 1:1.1, and it was allowed to stand at 30°C for 8 hours. The carrier A adsorbed with potassium chloride was obtained by filtration. The carrier A was dried at 100°C for 8 hours. The dried carrier A was then calcined at 350°C for 2 hours in a nitrogen atmosphere to obtain the carrier B. The carrier B was contacted with an aqueous solution with a concentration of 30 mg / mL of chloroplatinic acid, the volume of the carrier B: the volume ratio of the chloroplatinic acid aqueous solution = 1:1.3, the contact temperature was 50°C, and the contact time was 2 hours. The catalyst precursor C was then obtained by filtration and drying at 100°C for 7 hours. The catalyst precursor C was calcined at 500°C in a nitrogen atmosphere with an oxygen content of 10 vol% for 4 hours, and then reduced in a hydrogen atmosphere at 350°C for 6 hours to obtain the desired catalyst.

[0075] ICP test is used to determine the content of alkaline metal elements and platinum elements in the catalyst; ammonia chemical adsorption is used to test the acid content of the catalyst; transmission electron microscopy is used to standardize the size of the catalyst nanoparticles, such as Figure 2 As shown, the average size of the platinum nanoparticles in the catalyst can be known through particle statistics. The average size of the nanoparticles in the catalyst is 4.32nm, indicating that too high a basic metal content in the catalyst will lead to an increase in the size of the platinum nanoparticles and a decrease in catalyst performance. The specific results are summarized in Table 1.

[0076] Dehydrogenation of methylcyclohexane to produce hydrogen:

[0077] In a reaction tube, the catalyst and methylcyclohexane were reacted in a hydrogen atmosphere. The catalyst loading was 1 g, the reaction temperature was 470 ° C, and the mass space velocity of methylcyclohexane was 4 h -1 The products of reaction time 2h and reaction time 100h were analyzed to calculate the conversion rate of methylcyclohexane. The results are summarized in Table 1.

[0078] Comparative Example 4

[0079] The alumina carrier was placed in an aqueous solution with a potassium chloride concentration of 10 mg / mL, the volume of alumina: the volume of potassium chloride aqueous solution = 1:1.1, and it was allowed to stand at 30°C for 8 hours. The carrier A adsorbed with potassium chloride was obtained by filtration. The carrier A was dried at 100°C for 8 hours. The dried carrier A was then calcined at 350°C for 2 hours in a nitrogen atmosphere to obtain the carrier B. The carrier B was contacted with an aqueous solution with a concentration of 30 mg / mL of chloroplatinic acid, the volume of the carrier B: the volume ratio of the chloroplatinic acid aqueous solution = 1:1.3, the contact temperature was 50°C, and the contact time was 2 hours. The catalyst precursor C was then obtained by filtration and drying at 100°C for 7 hours. The catalyst precursor C was calcined at 500°C in a nitrogen atmosphere with an oxygen content of 40 vol% for 4 hours, and then reduced in a hydrogen atmosphere at 350°C for 6 hours to obtain the desired catalyst.

[0080] The ICP test was used to determine the alkaline metal elements and platinum content in the catalyst; the ammonia chemical adsorption was used to test the acid content of the catalyst; and the transmission electron microscope was used to standardize the size of the catalyst nanoparticles. The results are summarized in Table 1.

[0081] Dehydrogenation of methylcyclohexane to produce hydrogen:

[0082] In a reaction tube, the catalyst and methylcyclohexane were reacted in a hydrogen atmosphere. The catalyst loading was 1 g, the reaction temperature was 470 ° C, and the mass space velocity of methylcyclohexane was 4 h -1 The products of reaction time 2h and reaction time 100h were analyzed to calculate the conversion rate of methylcyclohexane. The results are summarized in Table 1.

[0083] Comparative Example 5

[0084] Same as Example 1, except that the temperature of the two contact immersions is both 50°C.

[0085] Table 1

[0086]

[0087] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A catalyst, characterized in that The catalyst comprises a carrier, metal Pt and an alkaline metal; the particle size of the metal Pt in the catalyst is 1.2-2.5 nm, and the total acid content of the catalyst is 150-350 μmol NH3 / g.

2. The catalyst according to claim 1, wherein The particle size of the metal Pt in the catalyst is 1.22-2.13 nm; and / or The total acid content of the catalyst is 170-330 μmol NH3 / g.

3. The catalyst according to claim 1 or 2, wherein The weight ratio of the alkaline metal to Pt in the catalyst is 0.01-30.

4. The catalyst according to any one of claims 1 to 3, wherein Based on the total mass of the catalyst, the catalyst comprises: The Pt content is 0.1-1.2wt%, preferably 0.2-1wt%; The basic metal content is 0.01-3wt%, preferably 0.1-3wt%; The carrier content is 95.8-99.89wt%, preferably 96-99.7wt%.

5. The catalyst according to any one of claims 1 to 4, wherein The carrier is selected from alumina and / or titania, preferably alumina; and / or The alkaline metal is an alkali metal and / or an alkaline earth metal, preferably at least one of potassium, calcium, sodium, magnesium, cesium, rubidium, and lithium, preferably at least one of potassium, calcium, and magnesium.

6. The method for preparing the catalyst according to any one of claims 1 to 5, characterized in that: The preparation method comprises: (a) subjecting a catalyst support to a first contact with an impregnation solution containing an alkaline metal, a first drying, and a first calcination to obtain a precursor; (b) the precursor is contacted with an impregnation solution containing metal platinum for a second time, dried for a second time, calcined for a second time, and optionally reduced; The conditions of the first contact include: the volume of the catalyst support: the volume of the impregnation solution containing the alkaline metal dissolved therein = 1: 1.05-1.2, and the contact temperature is 20-40° C.; The first calcination is carried out in an inert atmosphere; The conditions of the second contact include: precursor volume: impregnation solution volume containing metal platinum = 1.2-1.5, contact temperature 50-80°C; The second calcination is performed in an oxidative atmosphere with an oxygen content of 5-15 vol%.

7. The preparation method according to claim 6, wherein: The temperature of the second contacting is 10-60°C higher than the temperature of the first contacting, preferably 20-40°C higher.

8. The preparation method according to claim 6 or 7, wherein: The first calcination conditions include: calcination at 300-500° C. for 2-4 hours; and / or The second calcination conditions include: calcination at 450-550° C. for 1-3 hours; and / or The reduction conditions include: 350-450° C., and 4-8 hours of reduction.

9. Use of the catalyst according to any one of claims 1 to 5 in a dehydrogenation reaction, preferably in the dehydrogenation of cyclohexane compounds.

10. A method for dehydrogenating cyclohexane compounds, characterized in that: The method comprises: under the catalyst conditions described in any one of claims 1 to 5, a cyclohexane compound raw material is contacted with hydrogen for reaction; preferably, The cyclohexane compound is an alkylcyclohexane; and / or The conditions of the contact reaction include: The reaction temperature is 350-500°C; and / or The mass space velocity of alkyl cyclohexane is 1-10h -1 .

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