High-activity and high-selectivity dehydrogenation metal catalyst as well as preparation method and application thereof

Abstract

The invention relates to a high-activity and high-selectivity dehydrogenation metal catalyst and a preparation method and application thereof, the high-activity and high-selectivity dehydrogenation metal catalyst comprises a titanium dioxide carrier and platinum nanoparticles, the average size of the platinum nanoparticles is 1-2 nm, and the platinum nanoparticles are uniformly distributed on the titanium dioxide carrier. According to the invention, titanium dioxide is preferably selected as the catalyst carrier, so that the activity and selectivity of the catalyst are improved, the catalyst with fine and uniformly distributed platinum nanoparticles is obtained, the dehydrogenation degree of the organic hydrogen carrier can be improved by more than 20%, the dehydrogenation degree can be up to more than 90%, and the selectivity of an effective dehydrogenation product is more than 99%.

Description

Technical Field

[0001] The present invention relates to the technical field of organic catalysis, and in particular to a high-activity and high-selectivity dehydrogenation metal catalyst and a preparation method and application thereof. Background Art

[0002] Hydrogen energy is a clean energy with zero carbon emissions. The development of hydrogen storage and transportation technology plays an important role in realizing the application of hydrogen energy. The storage and transportation of hydrogen energy mainly include solid hydrogen storage, high-pressure gaseous hydrogen storage, liquid hydrogen storage, solid hydrogen storage and organic liquid hydrogen storage. Organic liquid hydrogen storage technology is an emerging method of hydrogen energy storage and transportation. It has the characteristics of convenient transportation, high hydrogen storage density and high safety, and is expected to solve the current problem of long-distance transportation of hydrogen. Organic liquid hydrogen storage technology uses liquid organic hydrogen carriers and hydrogen to undergo a reversible chemical reaction under the action of a catalyst to generate alkane compounds to achieve hydrogen storage and release. The liquid organic hydrogen carriers under research include cycloalkanes, carbazoles, N-heterocycles, etc. Among them, dibenzyltoluene has become a liquid organic hydrogen carrier with great application potential due to its high hydrogen storage density, low cost (commonly used heat transfer oil in industry), non-flammable, non-explosive, non-volatile, and low melting point.

[0003] Currently, the most studied catalyst for perhydrodibenzyltoluene is Pt / Al2O3, but it still has problems such as low reaction efficiency and low dehydrogenation degree of effective products. The literature (ChemSusChem, 2014, 7, 229-235) compared four platinum catalysts with different carriers (5% Pt / Al2O3, 5% Pt / HAP, 5% The dehydrogenation reaction performance of perhydrodibenzyltoluene on Pt / SBA-15, 5% Pt / C), among which the dehydrogenation efficiency on 5% Pt / Al2O3 is higher, and the dehydrogenation degree is 54.5% after reacting for 3 hours at 270°C and normal pressure. When the reaction time is extended to 5 hours, the dehydrogenation degree is slightly increased to 56.3%; the literature (Catal. Sci. Technol., 2022, 12, 1441-1449) and the patent (CN113368897A) use dielectric barrier discharge organic plasma to pretreat an alumina carrier to prepare a high-activity alumina-supported platinum catalyst, among which the dehydrogenation efficiency on 3% Pt / Al2O3-P-HAc is higher, and the dehydrogenation degree can reach 74.8% after reacting for 5 hours at 270°C and normal pressure.

[0004] In the above studies, the loading amount of precious metal platinum is high and the hydrogen production efficiency is low, which is not conducive to industrial production, and the hydrogen production efficiency of the catalyst needs to be improved. In addition, the literature (International Journal of Hydrogen Energy, 2021, 46, 34797-34806) summarizes the correspondence between the degree of dehydrogenation and the effective dehydrogenation product: the effective product selectivity and the degree of dehydrogenation are generally negatively correlated, that is, the higher the degree of dehydrogenation, the lower the effective product selectivity. The reduction in the selectivity of the effective product will not only cause the loss of the liquid organic hydrogen carrier, but also easily cause carbon accumulation on the catalyst surface, causing the catalyst to deactivate.

[0005] Therefore, there is an urgent need to design highly active and highly selective catalysts that can achieve high dehydrogenation degrees while maintaining high effective product selectivity. Summary of the invention

[0006] In order to solve the above technical problems, the present invention adopts titanium dioxide as a catalyst carrier, thereby improving the dehydrogenation efficiency and effective product selectivity of the liquid phase organic hydrogen carrier.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a high-activity and high-selectivity dehydrogenation metal catalyst, which comprises a titanium dioxide carrier and platinum nanoparticles, wherein the average size of the platinum nanoparticles is 1 to 2 nm, for example, 1 nm, 1.2 nm, 1.4 nm, 1.6 nm, 1.8 nm or 2 nm, etc., and the platinum nanoparticles are uniformly distributed on the titanium dioxide carrier.

[0009] As a preferred technical solution of the present invention, the loading amount of the platinum nanoparticles is 0.3-4wt%, for example, it can be 0.3wt%, 1wt%, 2wt%, 3wt% or 4wt%.

[0010] The present invention prepares a highly active and highly selective dehydrogenation catalyst by uniformly loading platinum on the surface of a titanium dioxide carrier, thereby solving the technical problems of high noble metal loading, low dehydrogenation efficiency and low selectivity of traditional platinum-alumina dehydrogenation catalysts, and achieving the technical effect of highly active and highly selective dehydrogenation.

[0011] In a second aspect, the present invention provides a method for preparing the high-activity and high-selectivity dehydrogenation metal catalyst according to the first aspect, the method comprising the following steps:

[0012] (1) loading a platinum precursor solution onto the surface of a titanium dioxide support by wet impregnation to obtain a precursor support;

[0013] (2) The precursor support is dried and calcined in sequence to obtain the supported low noble metal content catalyst.

[0014] As a preferred technical solution of the present invention, the platinum precursor solution in step (1) is a mixed solution of a platinum precursor dissolved in an organic solvent and pure water.

[0015] Preferably, the platinum precursor includes any one of chloroplatinic acid, tetraammine platinum nitrate, platinum acetylacetonate, or platinum sulfite.

[0016] Preferably, the organic solvent includes any one of ethanol, methanol, isopropanol, or tetrahydrofuran.

[0017] Preferably, the volume content of the organic solvent in the mixed solution is 0-80%, for example, 0%, 5%, 10%, 20%, 60% or 80%.

[0018] As a preferred technical solution of the present invention, the immersion time of the wet immersion in step (1) is 1 to 18 hours, for example, it can be 1 hour, 5 hours, 10 hours, 14 hours or 18 hours.

[0019] As a preferred technical solution of the present invention, the drying temperature in step (2) is 100-120°C, for example, it can be 100°C, 105°C, 110°C, 115°C or 120°C.

[0020] Preferably, the drying time in step (2) is not less than 10 h, for example, it can be 10 h, 12 h, 14 h, 16 h, 20 h or 40 h.

[0021] As a preferred technical solution of the present invention, the calcination temperature in step (2) is 400-500°C, for example, it can be 400°C, 420°C, 440°C, 480°C or 500°C.

[0022] The present invention optimizes the calcination temperature to be within the range of 400-500° C., so as to calcine the platinum precursor into platinum oxide while avoiding agglomeration caused by excessively high temperature.

[0023] Preferably, the calcination time is 0.5 to 5 h, for example, 0.5 h, 1 h, 2 h, 3 h or 5 h.

[0024] As a preferred technical solution of the present invention, the highly active and highly selective dehydrogenation metal catalyst is subjected to reduction treatment before use.

[0025] Preferably, the reduction treatment uses hydrogen or a mixture of hydrogen and nitrogen as the reducing gas.

[0026] Preferably, the hydrogen content of the reducing gas is 10-100%, for example, 10%, 40%, 60%, 80% or 100%.

[0027] Preferably, the volume space velocity of the reducing gas is 500 to 2000 h -1 , for example, it can be 500h -1 , 800h -1 、1000h -1 、1500h -1 or 2000h -1 wait.

[0028] Preferably, the pressure of the reduction treatment is 0.1-1.0 MPa, for example, 0.1 MPa, 0.2 MPa, 0.4 MPa, 0.8 MPa or 1.0 MPa.

[0029] Preferably, the temperature of the reduction treatment is 300-700°C, for example, 300°C, 400°C, 500°C, 600°C or 700°C, and preferably 350-550°C.

[0030] The present invention reduces the calcined platinum oxide into platinum nanoparticles through reduction treatment, and the reduction temperature is preferably in the range of 350-550° C., ensuring that the platinum can be fully reduced for dehydrogenation reaction while avoiding agglomeration of the platinum nanoparticles caused by excessively high temperature.

[0031] Preferably, the heating rate of the reduction treatment is 1-10°C / min, for example, 1°C / min, 2°C / min, 5°C / min, 8°C / min or 10°C / min.

[0032] Preferably, the reduction treatment time is 0.5 to 5 h, for example, 0.5 h, 1 h, 2 h, 4 h or 5 h.

[0033] In a third aspect, the present invention provides an application of the high-activity and high-selectivity dehydrogenation metal catalyst described in the first aspect, wherein the application includes dehydrogenation of a liquid organic hydrogen storage carrier.

[0034] As a preferred technical solution of the present invention, the liquid organic hydrogen storage carrier includes any one of perhydrodibenzyltoluene, perhydromonobenzyltoluene, methylcyclohexane, decahydronaphthalene or bicyclohexane, and is more preferably perhydrodibenzyltoluene.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] (1) The present invention significantly improves the dehydrogenation efficiency and effective dehydrogenation product selectivity of the liquid organic hydrogen storage carrier by preparing a highly active and highly selective catalyst in which platinum nanoparticles are uniformly distributed on a titanium dioxide carrier, thereby increasing the dehydrogenation degree by more than 20% and achieving an effective dehydrogenation product selectivity of 99.4%.

[0037] (2) The high-activity and high-selectivity dehydrogenation metal catalyst provided by the present invention overcomes the problem that the selectivity of conventional catalysts decreases significantly with increasing dehydrogenation degree, and maintains high selectivity under high-activity conditions. When the dehydrogenation degree reaches 91.2%, the selectivity can still be maintained at 99.2%. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a scanning electron microscope image of the high-activity and high-selectivity dehydrogenation metal catalyst prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0040] Example 1

[0041] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst and its preparation method and application, such as Figure 1 As shown, the catalyst composition is Pt: 1wt%, the rest is TiO2 carrier, and the average size of the platinum nanoparticles is 1.4nm.

[0042] The catalyst was prepared by an impregnation method. The specific preparation steps included: dissolving 0.265 g of chloroplatinic acid in a mixed solution of ethanol and water, wherein the volume content of ethanol was 0%, and loading it on a 10 g TiO2 carrier by an impregnation method. The impregnation time was 24 h, followed by drying in an oven at 120 ° C for 12 h, and calcining in a muffle furnace at 500 ° C for 4 h. Before the reaction, the catalyst was reduced and activated using hydrogen. The reduction conditions were: using pure hydrogen as the raw material at a volume space velocity of 2000 h -1 , the reduction reaction pressure is 0.1MPa, the reduction temperature is 500℃, the reduction temperature is programmed and the heating rate is controlled at 3℃ / min, and the reduction time is 1h. After the reduction is completed, an intermittent reactor is used to evaluate the dehydrogenation reaction activity. The reaction raw material is perhydrodibenzyltoluene (effective ingredient ≥ 98%), the reaction pressure is normal pressure, the reaction temperature is 300℃, the raw material loading amount is 30g, the catalyst dosage is 1g (the molar ratio of platinum to the reactant perhydrodibenzyltoluene is 0.05%), and the reaction time is 3h.

[0043] Example 2

[0044] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst, a preparation method and an application thereof, wherein the catalyst composition is Pt: 0.3wt%, the rest is TiO2 carrier, and the average size of the platinum nanoparticles is 1.0nm.

[0045] The catalyst was prepared by an impregnation method. The specific preparation steps included: dissolving 0.080 g of chloroplatinic acid in a mixed solution of ethanol and water, wherein the volume content of ethanol was 20%, and loading it on a 10 g TiO2 carrier by an impregnation method. The impregnation time was 32 h, followed by drying in an oven at 100 ° C for 15 h, and calcining in a muffle furnace at 400 ° C for 5 h. Before the reaction, the catalyst was reduced and activated using hydrogen. The reduction conditions were: using pure hydrogen as the raw material at a volume space velocity of 1000 h -1 , the reduction reaction pressure is 1.0MPa, the reduction temperature is 350℃, the reduction temperature is programmed and the heating rate is controlled at 5℃ / min, and the reduction time is 5h. After the reduction is completed, an intermittent reactor is used to evaluate the dehydrogenation reaction activity. The reaction raw material is perhydrodibenzyltoluene (effective ingredient ≥ 98%), the reaction pressure is normal pressure, the reaction temperature is 300℃, the raw material loading amount is 30g, the catalyst dosage is 3.3g (the molar ratio of platinum to the reactant perhydrodibenzyltoluene is 0.05%), and the reaction time is 3h.

[0046] Example 3

[0047] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst, a preparation method and an application thereof, wherein the catalyst composition is Pt: 4wt%, the rest is TiO2 carrier, and the average size of the platinum nanoparticles is 2.0nm.

[0048] The catalyst was prepared by an impregnation method. The specific preparation steps included: dissolving 1.061 g of chloroplatinic acid in a mixed solution of ethanol and water, wherein the volume content of ethanol was 80%, and loading it on a 10 g TiO2 carrier by an impregnation method. The impregnation time was 27 h, followed by drying in an oven at 110 ° C for 13 h, and calcining in a muffle furnace at 480 ° C for 0.5 h. Before the reaction, the catalyst was reduced and activated using hydrogen. The reduction conditions were: using pure hydrogen as the raw material at a volume space velocity of 500 h -1 , the reduction reaction pressure is 0.1MPa, the reduction temperature is 550℃, the reduction temperature is programmed and the heating rate is controlled at 10℃ / min, and the reduction time is 0.5h. After the reduction, an intermittent reactor is used to evaluate the dehydrogenation reaction activity. The reaction raw material is perhydrodibenzyltoluene (effective ingredient ≥ 98%), the reaction pressure is normal pressure, the reaction temperature is 300℃, the raw material loading amount is 30g, the catalyst dosage is 0.25g (the molar ratio of platinum to the reactant perhydrodibenzyltoluene is 0.05%), and the reaction time is 3h.

[0049] Example 4

[0050] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst and its preparation method and application. Except for the reduction temperature being 300° C., the rest is the same as that of Example 1.

[0051] Example 5

[0052] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst and its preparation method and application. Except for the reduction temperature of 700° C., the rest is the same as Example 1.

[0053] Example 6

[0054] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst and a preparation method and application thereof. Except that calcination is not performed during the preparation, the rest is the same as that of Example 1.

[0055] Example 7

[0056] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst and its preparation method and application. Except for the calcination temperature of 300° C., the rest is the same as Example 1.

[0057] Example 8

[0058] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst and its preparation method and application. Except for the calcination temperature of 600° C., the rest is the same as Example 1.

[0059] Example 9

[0060] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst and its preparation method and application. Except for the reduction temperature being 200° C., the rest is the same as that of Example 1.

[0061] Example 10

[0062] This embodiment provides a high-activity and high-selectivity dehydrogenation metal catalyst and its preparation method and application. Except for the reduction temperature being 800° C., the rest is the same as that of Example 1.

[0063] Comparative Example 1

[0064] The catalyst used in this comparative example is Pt / Al2O3, whose composition is Pt: 1wt%, and the rest is Al2O3 carrier. Except for the selected carrier, the catalyst preparation method and reaction conditions are the same as those in Example 1.

[0065] Comparative Example 2

[0066] The catalyst used in this comparative example is Pt / CeO2, which has a composition of Pt: 1wt% and the rest is Al2O3 carrier. Except for the selected carrier, the catalyst preparation method and reaction conditions are the same as those in Example 1.

[0067] Comparative Example 3

[0068] The catalyst used in this comparative example is Pt / Beta molecular sieve, which has a composition of Pt: 1wt% and the rest is Al2O3 carrier. Except for the selected carrier, the catalyst preparation method and reaction conditions are the same as those in Example 1.

[0069] Comparative Example 4

[0070] The catalyst used in this comparative example is Pt / SiO2, which has a composition of Pt: 1wt% and the rest is Al2O3 carrier. Except for the selected carrier, the catalyst preparation method and reaction conditions are the same as those in Example 1.

[0071] Comparative Example 5

[0072] This comparative example is the same as comparative example 1 except that the reaction time is 15 h.

[0073] Comparative Example 6

[0074] This comparative example is the same as Example 1 except that the catalyst preparation method adopts ethylene glycol reduction method.

[0075] The steps of the ethylene glycol reduction method are as follows: 0.053g of chloroplatinic acid is dissolved in 50mL of ethylene glycol, then 2g of TiO2 is added, stirred at room temperature for 4h, then 0.5mol / L of sodium hydroxide-ethylene glycol solution is added, pH is adjusted to 12, then refluxed at 160°C for 3h under N2 protection, cooled to room temperature, filtered and washed with deionized water and ethanol solution, and finally dried in a vacuum oven at 60°C for 8h to obtain the catalyst.

[0076] The average size of platinum nanoparticles on the catalyst surface obtained in this comparative example is about 3 nm.

[0077] Test Method

[0078] The reactivity of the catalyst was evaluated in a batch reactor.

[0079] The liquid organic hydrogen storage carrier and the high-activity and high-selectivity dehydrogenation metal catalyst are used to carry out catalytic dehydrogenation reaction in an intermittent tank reactor to obtain a dehydrogenation product.

[0080] A flow meter is used to monitor the real-time rate of hydrogen online.

[0081] Test Standards

[0082] Dehydrogenation degree = hydrogen production / theoretical maximum hydrogen production

[0083] Theoretical maximum hydrogen production = raw material mass / raw material molar mass*9*22.4*1000

[0084] Test Results

[0085] Table 1

[0086]

[0087]

[0088] "-" in the table means no data

[0089] The test results show that:

[0090] (1) It can be seen from Examples 1 to 3 that the present invention can achieve high-activity and high-selectivity catalytic dehydrogenation of perhydrodibenzyltoluene by selecting titanium dioxide as a catalyst carrier so that nano-scale platinum nanoparticles are evenly distributed on the carrier surface, and the dehydrogenation degree can reach more than 88% and the selectivity can reach more than 99%.

[0091] (2) It can be seen from Examples 1 and 4 to 5 that the present invention can achieve better dehydrogenation effect within the preferred reduction temperature range. When the reduction temperature is 300°C, the dehydrogenation degree drops to 69.2%, and when the reduction temperature is 700°C, the dehydrogenation degree drops to 37.7%.

[0092] (3) It can be seen from Examples 1 and 6 to 8 that when no calcination is performed, the degree of dehydrogenation decreases from 91.2% in Example 1 to 40.7% in Example 6, and the selectivity decreases from 99.2% in Example 1 to 98.6% in Example 6. When the calcination temperature is 300°C, the degree of dehydrogenation drops sharply to 35.8%. When the calcination temperature is 600°C, the platinum on the surface of titanium dioxide agglomerates in large quantities and cannot be evenly distributed on the surface of the carrier, and the prepared catalyst loses its catalytic ability. This shows that the preferred calcination temperature of the present invention improves the activity of the catalyst.

[0093] (4) It can be seen from Examples 1 and 9 to 10 that the present invention further optimizes the reduction temperature. When the reduction temperature is 200°C, the catalyst is not fully reduced, the utilization rate of the platinum nanoparticles decreases, and the dehydrogenation degree decreases to 55.0%. When the reduction temperature is 800°C, platinum agglomerates during the reduction process, the uniformity of the carrier distribution decreases, and the dehydrogenation degree decreases to 12.5%.

[0094] (5) It can be seen from Example 1 and Comparative Examples 1 to 4 that the present invention screened a variety of catalyst carriers, and several carriers showed a dehydrogenation degree that was more than 20% lower than that of the high-activity and high-selectivity metal catalyst of the present invention, indicating the superiority of the titanium dioxide catalyst carrier selected by the present invention in the dehydrogenation reaction of liquid-phase organic hydrogen carrier.

[0095] (6) It can be seen from Example 1 and Comparative Examples 1 and 5 that the present invention extends the reaction time from 3 h in Comparative Example 1 to 14 h in Comparative Example 5, indicating that the catalyst of the present invention has high selectivity under similar dehydrogenation degrees. Since the selectivity of effective products and the dehydrogenation degree on the same catalyst are negatively correlated, that is, the higher the dehydrogenation degree, the lower the selectivity of effective products, the dehydrogenation degree on the 1wt% Pt / Al2O3 catalyst of Comparative Example 5 can be increased to 88.6%, but the dehydrogenation degree of effective products is significantly reduced from 97.5% to 90.4%; the dehydrogenation degrees of Comparative Example 5 and Example 1 are relatively close, but the selectivity of effective dehydrogenation products on the 1wt% Pt / TiO2 catalyst in Example 1 is significantly higher, reaching 99.2%, that is, the present invention maintains high selectivity while having a high dehydrogenation degree.

[0096] (7) It can be seen from Example 1 and Comparative Example 6 that when the ethylene glycol reduction method is used to prepare the catalyst, the platinum nanoparticles on the catalyst surface are larger, the platinum utilization rate is reduced, and the dehydrogenation degree decreases from 91.2% in Example 1 to 45.3%.

[0097] In summary, the present invention prepares a platinum / titanium dioxide catalyst, uniformly distributes platinum nanoparticles on the surface of a titanium dioxide carrier, and applies the catalyst to a liquid-phase hydrogen carrier dehydrogenation reaction. In an intermittent reactor, at a reaction temperature of 300° C., the metal catalyst of the present invention can increase the dehydrogenation degree of the organic hydrogen carrier by more than 20% compared with the most commonly used Pt / Al2O3 catalyst, and the highest dehydrogenation degree can reach more than 90%, while the selectivity of the effective dehydrogenation product is more than 99%.

[0098] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A highly active and highly selective dehydrogenation metal catalyst, characterized in that: The high-activity and high-selectivity dehydrogenation metal catalyst comprises a titanium dioxide carrier and platinum nanoparticles. The average size of the platinum nanoparticles is 1-2 nm, and the platinum nanoparticles are uniformly distributed on the titanium dioxide carrier.

2. The highly active and highly selective dehydrogenation metal catalyst according to claim 1, characterized in that: The loading amount of the platinum nanoparticles is 0.3-4 wt %.

3. A method for preparing the highly active and highly selective dehydrogenation metal catalyst according to claim 1 or 2, characterized in that: The method comprises the following steps: (1) loading a platinum precursor solution onto the surface of a titanium dioxide support by wet impregnation to obtain a precursor support; (2) The precursor support is dried and calcined in sequence to obtain the supported low noble metal content catalyst.

4. The method according to claim 3, characterized in that The platinum precursor solution in step (1) is a mixed solution of a platinum precursor dissolved in an organic solvent and pure water; Preferably, the platinum precursor includes any one of chloroplatinic acid, tetraammine platinum nitrate, platinum acetylacetonate or platinum sulfite; Preferably, the organic solvent comprises any one of ethanol, methanol, isopropanol or tetrahydrofuran; Preferably, the volume content of the organic solvent in the mixed solution is 0 to 80%.

5. The method according to claim 3 or 4, characterized in that: The impregnation time of the wet impregnation in step (1) is 1 to 18 hours.

6. The method according to any one of claims 3 to 5, characterized in that: The drying temperature in step (2) is 100-120° C. Preferably, the drying time in step (2) is not less than 10 hours.

7. The method according to any one of claims 3 to 6, characterized in that: The calcination temperature in step (2) is 400-500° C. Preferably, the calcination time in step (2) is 0.5 to 5 hours.

8. The method according to any one of claims 3 to 7, characterized in that: The high-activity and high-selectivity dehydrogenation metal catalyst is subjected to reduction treatment before use; Preferably, the reduction treatment uses hydrogen or a mixture of hydrogen and nitrogen as the reducing gas; Preferably, the hydrogen content of the reducing gas is 10 to 100%; Preferably, the volume space velocity of the reducing gas is 500 to 2000 h -1 ; Preferably, the pressure of the reduction treatment is 0.1-1.0 MPa; Preferably, the temperature of the reduction treatment is 300 to 700°C, preferably 350 to 550°C; Preferably, the heating rate of the reduction treatment is 1 to 10°C / min; Preferably, the reduction treatment time is 0.5 to 5 hours.

9. Use of a highly active and highly selective dehydrogenation metal catalyst according to claim 1 or 2, characterized in that: The applications include dehydrogenation of liquid organic hydrogen storage carriers.

10. The use of the high-activity and high-selectivity dehydrogenation metal catalyst according to claim 9, characterized in that: The liquid organic hydrogen storage carrier includes any one of perhydrodibenzyltoluene, perhydromonobenzyltoluene, methylcyclohexane, decahydronaphthalene or bicyclohexane, preferably perhydrodibenzyltoluene.

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