Supported low-noble-metal-content catalyst as well as preparation method and application thereof

Abstract

The invention relates to a supported low-noble-metal-content catalyst and a preparation method and application thereof, the supported low-noble-metal-content catalyst comprises a catalyst carrier and an active component, the content of the active component is 0.2-0.4 wt%, and the relative immersion depth of the active component is 0.05-0.16. Compared with a high-content noble metal-based dehydrogenation catalyst, the low-noble metal-content catalyst disclosed by the invention has the advantages that the similar dehydrogenation degree can be achieved under the same catalyst filling amount and reaction conditions, the hydrogen production efficiency of the noble metal per unit mass is obviously improved, and the cost of the dehydrogenation catalyst is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of organic catalysis, and in particular to a supported catalyst with low noble metal content and a preparation 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 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, perhydrodibenzyltoluene is usually dehydrogenated using platinum-based catalysts, which has problems such as low dehydrogenation efficiency and high cost. Using a continuous fixed bed reactor at 300°C and a liquid space velocity of 1h -1 Under the conditions of , CeO2-supported platinum catalyst can achieve a maximum conversion rate of 95% for perhydrodibenzyltoluene (International Journal of Hydrogen Energy, 2021, 46 (7), 5520). However, the amount of platinum used reaches 5wt%, which increases the cost of the catalyst. At 280°C, the liquid space velocity is 1h -1 Under the reaction conditions, the dehydrogenation degree of dibenzyltoluene using a standard 0.5% Pt / Al2O3 catalyst (purchased from Sigma-Aldrich Reagent Company) is only 38.0%, and a dehydrogenation degree of 60% can only be achieved when the reaction temperature is increased to 340°C (Energy Conversion and Management, 2021, 239(1), 114124). In summary, platinum-based catalysts have problems such as low dehydrogenation activity or high platinum dosage, which limits the use of dibenzyltoluene in hydrogen storage and release technology.

[0004] In summary, the existing technology has the problem of high loading of precious metal platinum and low hydrogen production efficiency per unit mass of platinum, which is not conducive to industrial application. Therefore, the hydrogen production efficiency per unit mass of platinum on the catalyst still needs to be improved, and how to achieve high-efficiency hydrogen production with low precious metal loading has become a problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve the above technical problems, the present invention develops a high-efficiency and low-cost catalyst for dehydrogenation of liquid-phase organic hydrogen carriers to solve the problems of high precious metal usage and high cost in current precious metal-based dehydrogenation catalysts.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a supported low-precious metal content catalyst, which includes a catalyst carrier and an active component, wherein the content of the active component is 0.2-0.4wt%, for example, it can be 0.2wt%, 0.25wt%, 0.3wt%, 0.35wt% or 0.4wt%, etc., and the relative impregnation depth of the active component is 0.05-0.16, for example, it can be 0.05, 0.1, 0.12, 0.14 or 0.16, etc., and the relative impregnation depth is the ratio of the impregnation depth to the radius of the catalyst carrier particle.

[0008] The present invention improves the distribution uniformity of active components on the catalyst by regulating the impregnation depth of the catalyst, promotes the effective utilization of active components on the catalyst carrier, solves the technical problem of high cost of catalysts with high precious metal content in the prior art, and achieves efficient catalysis with low precious metal content.

[0009] Preferably, the active component comprises platinum.

[0010] Preferably, the catalyst carrier comprises aluminum oxide, silicon oxide, activated carbon, zirconium oxide, titanium oxide or molecular sieve.

[0011] Preferably, the particle size of the catalyst carrier is 2 to 4 mm, for example, 2 mm, 2.5 mm, 3 mm, 3.5 mm or 4 mm.

[0012] Preferably, the impregnation depth of the active component is 0.1-0.32 mm, for example, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm or 0.32 mm.

[0013] The present invention optimizes the particle size of the catalyst carrier so that the fixed bed filled with the catalyst of the present invention has a suitable pressure drop and catalyst specific surface area, and optimizes the impregnation depth of the active component so that the active substances on the surface of the catalyst of the present invention have a good distribution state, thereby improving the utilization rate of the surface active substances.

[0014] In a second aspect, the present invention provides a method for preparing the supported low noble metal content catalyst according to the first aspect, the method comprising the following steps:

[0015] (1) Spraying the precursor solution of the active component uniformly on the surface of the catalyst support and impregnating it at room temperature;

[0016] (2) rotary evaporating the impregnated catalyst support to remove the solvent to obtain a precursor support;

[0017] (3) The precursor support is dried and calcined in sequence to obtain the supported low noble metal content catalyst.

[0018] Preferably, the precursor solution is a mixed solution of a noble metal precursor dissolved in an organic solvent and pure water.

[0019] Preferably, the noble metal precursor comprises chloroplatinic acid.

[0020] Preferably, the volume content of the organic solvent in the mixed solution is 5-80%, for example, 5%, 10%, 20%, 60% or 80%.

[0021] Preferably, the organic solvent comprises ethanol.

[0022] Preferably, the immersion time is 0.2 to 10 h, for example, 0.2 h, 1 h, 4 h, 8 h or 10 h.

[0023] The method for preparing a supported low-noble metal content catalyst provided by the present invention optimizes the stirring and impregnation time. Within the impregnation time of 0.2 to 10 hours, the catalyst prepared by the present invention can have an appropriate impregnation depth, avoiding the situation where the impregnation time is too short and the precursor loading is uneven, and the impregnation depth is too deep due to too long time, and the internal active substances are difficult to be efficiently utilized in the catalytic process.

[0024] Preferably, the pressure of the rotary evaporation is -0.10 to -0.05 MPa, for example, it may be -0.10 MPa, -0.09 MPa, -0.08 MPa, -0.07 MPa, -0.06 MPa or -0.05 MPa.

[0025] Preferably, the temperature of the rotary evaporation is 30-80°C, for example, 30°C, 40°C, 50°C, 60°C, 70°C or 80°C.

[0026] Preferably, the rotary evaporation time is 10 to 30 min, for example, 10 min, 15 min, 20 min, 25 min, or 30 min.

[0027] The present invention adopts a rotary evaporator to maintain a low temperature under negative pressure conditions to quickly remove the solvent, thereby avoiding the aggregation of precursor molecules located at different adsorption sites due to the effect of the solvent during the drying or calcination process, causing a large number of noble metal atoms on the surface of the catalyst after calcination to agglomerate, thereby resulting in a situation where the dispersion is low and the utilization rate of active atoms of the catalyst is low. At the same time, the rapid removal of solvent by rotary evaporation can more accurately regulate the immersion depth by adjusting the immersion time, thereby avoiding an excessive immersion depth caused by too long a solvent removal time.

[0028] Preferably, the drying temperature is 100-120°C, for example, 100°C, 105°C, 110°C, 115°C or 120°C.

[0029] Preferably, the drying time is 10 to 20 hours, for example, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours or 20 hours.

[0030] Preferably, the calcination temperature is 400-700°C, for example, 400°C, 450°C, 500°C, 550°C, 600°C or 700°C.

[0031] Preferably, the calcination time is 3 to 6 hours, for example, 3 hours, 3.5 hours, 4 hours, 5 hours or 6 hours.

[0032] Preferably, the supported low noble metal content catalyst is subjected to reduction treatment before use.

[0033] Preferably, the reduction treatment uses hydrogen or a mixture of hydrogen and nitrogen as the reducing gas.

[0034] Preferably, the hydrogen content of the reducing gas is 10-100%, for example, 10%, 40%, 60%, 80% or 100%.

[0035] 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.

[0036] 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.

[0037] Preferably, the temperature of the reduction treatment is 200-600°C, for example, 200°C, 300°C, 400°C, 500°C or 600°C.

[0038] 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.

[0039] Preferably, the reduction time is 0.5 to 5 h, for example, 0.5 h, 1 h, 2 h, 4 h or 5 h.

[0040] In a third aspect, the present invention provides an application of the supported low-noble metal content catalyst described in the first aspect, wherein the application includes dehydrogenation of a liquid organic hydrogen storage carrier.

[0041] Preferably, the liquid organic hydrogen storage carrier includes any one of perhydrodibenzyltoluene, perhydromonobenzyltoluene, methylcyclohexane, decahydronaphthalene or bicyclohexane, preferably perhydrodibenzyltoluene.

[0042] Preferably, the method for dehydrogenating the liquid organic hydrogen storage carrier comprises:

[0043] The liquid organic hydrogen storage carrier is passed through a fixed bed reactor filled with a supported low-noble metal content catalyst to carry out a catalytic dehydrogenation reaction to obtain a dehydrogenation product.

[0044] Preferably, the reaction temperature of the catalytic dehydrogenation reaction is 250-350°C, for example, 250°C, 280°C, 300°C, 320°C or 350°C.

[0045] Preferably, the amount of the supported low-noble metal content catalyst used is 5 to 100 g, for example, 5 g, 10 g, 20 g, 40 g, 60 g, 80 g or 100 g.

[0046] Preferably, the mass space velocity of the liquid organic hydrogen storage carrier is 0.1 to 20 h -1 , for example, it can be 0.1h -1 , 1h -1 , 2h -1 , 10h -1 or 20h -1 wait.

[0047] Compared with the prior art, the present invention has at least the following beneficial effects:

[0048] The present invention provides a supported catalyst with low precious metal content, which is applied to the dehydrogenation reaction of a liquid hydrogen carrier. Compared with a high-precious metal dehydrogenation catalyst, the catalyst with low precious metal content of the present invention can achieve a similar dehydrogenation degree under the same catalyst loading amount and reaction conditions. Overall, the efficiency of hydrogen production per unit mass of precious metal is greatly improved, and the cost of the dehydrogenation catalyst is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is the distribution diagram of platinum elements in the supported low-noble metal content catalyst prepared in Example 1. DETAILED DESCRIPTION

[0050] 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.

[0051] Example 1

[0052] This embodiment provides a supported catalyst with low noble metal content, wherein the catalyst carrier is alumina, the active component is platinum, the platinum loading is 0.25wt%, the alumina particle size is 3mm, and the platinum impregnation depth is 0.2mm. The catalyst is prepared by impregnation method, and the specific preparation steps include:

[0053] 0.66 g of chloroplatinic acid was dissolved in a mixed solution of 100 mL of ethanol and water, wherein the volume ratio of ethanol was 50%, and then sprayed on 100 g of alumina support by spraying, and after impregnation at room temperature for 4 h, it was transferred to a rotary evaporator and vacuumed with a water pump, and the solvent was removed in a water bath at 55°C for 20 min, and then dried in an oven at 120°C for 12 h, and then calcined in a muffle furnace at 500°C for 4 h. The platinum element distribution of the prepared supported catalyst is as follows: Figure 1 As shown, the particle size of the alumina sphere is 3 mm, and the platinum element is distributed within a depth of 0.2 mm in the outer layer of the alumina sphere.

[0054] Before the reaction, the catalyst was reduced and activated in situ using hydrogen in a fixed bed reactor. The specific conditions were as follows: 7 g of catalyst was filled, a mixture of nitrogen and hydrogen was used as the raw material (hydrogen volume content 50%), and the volumetric space velocity of the mixture was 2000 h -1 The reduction reaction pressure was 0.1 MPa, the reduction temperature was 300°C, the reduction temperature was programmed and the heating rate was controlled at 2°C / min, and the reduction time was 1 h.

[0055] Example 2

[0056] This embodiment provides a supported catalyst with low noble metal content, wherein the catalyst carrier is alumina, the active component is platinum, the platinum loading is 0.2wt%, the alumina particle size is 2mm, and the platinum impregnation depth is 0.1mm. The catalyst is prepared by impregnation method, and the specific preparation steps include:

[0057] 0.53 g of chloroplatinic acid was dissolved in a mixed solution of 100 mL of ethanol and water, wherein the volume ratio of ethanol was 5%, and then sprayed on 100 g of alumina carrier by spraying. After being immersed at room temperature for 0.5 h, it was transferred to a rotary evaporator and vacuumed with a water pump in a water bath at 50°C for 30 min to remove the solvent. Then, it was dried in an oven at 100°C for 20 h, and after drying, it was calcined in a muffle furnace at 400°C for 6 h.

[0058] Before the reaction, the catalyst was reduced and activated in situ using hydrogen in a fixed bed reactor. The specific conditions were as follows: 5 g of catalyst was filled, a mixture of nitrogen and hydrogen was used as the raw material (hydrogen volume content 10%), and the volumetric space velocity of the mixture was 500 h -1 The reduction reaction pressure was 0.5 MPa, the reduction temperature was 200°C, the reduction temperature was programmed and the heating rate was controlled at 1°C / min, and the reduction time was 5 h.

[0059] Example 3

[0060] This embodiment provides a supported catalyst with low noble metal content, wherein the catalyst carrier is alumina, the active component is platinum, the platinum loading is 0.4wt%, the alumina particle size is 4mm, and the platinum impregnation depth is 0.32mm. The catalyst is prepared by impregnation method, and the specific preparation steps include:

[0061] 1.06 g of chloroplatinic acid was dissolved in a mixed solution of 100 mL of ethanol and water, wherein the volume ratio of ethanol was 5%, and then sprayed on the alumina support by spraying. After being immersed at room temperature for 10 h, the solution was transferred to a rotary evaporator and vacuumed with a water pump in a water bath at 80°C for 10 min to remove the solvent. The solution was then dried in an oven at 110°C for 3 h, and then calcined in a muffle furnace at 700°C for 3 h.

[0062] Before the reaction, the catalyst was reduced and activated in situ using hydrogen in a fixed bed reactor. The specific conditions were: 100 g of catalyst was filled, hydrogen was used as the raw material, and the volume space velocity was 1000 h -1 The reduction reaction pressure is 1 MPa, the reduction temperature is 600°C, the reduction temperature is programmed and the heating rate is controlled at 10°C / min, and the reduction time is 0.5h.

[0063] Example 4

[0064] This embodiment is the same as Embodiment 1 except that rotary evaporation is not performed after the catalyst carrier is impregnated.

[0065] Example 5

[0066] This embodiment is the same as Embodiment 1 except that the temperature of the rotary evaporation is 25°C.

[0067] Example 6

[0068] This embodiment is the same as Embodiment 1 except that the temperature of the rotary evaporation is 90°C.

[0069] Comparative Example 1

[0070] This comparative example is the same as Example 1 except that the loading amount of platinum is 1.0 wt %.

[0071] Comparative Example 2

[0072] This comparative example is the same as Example 1 except that the immersion time is 0.1 hour and the immersion depth is 0.05 mm.

[0073] Comparative Example 3

[0074] This comparative example is the same as Example 1 except that the immersion time is 24 hours and the immersion depth is 0.6 mm.

[0075] Application Example 1

[0076] This application example provides a method for applying the supported low-noble metal content catalyst to the dehydrogenation of a liquid organic hydrogen storage carrier, the method comprising: after the reduction is completed, a dehydrogenation reaction is directly carried out in a fixed bed reactor, the reaction raw material is perhydrodibenzyltoluene (effective ingredient ≥ 98%), the reaction pressure is normal pressure, the reaction temperature is 290°C, and the liquid mass space velocity is 3.0h -1 The supported catalyst with low noble metal content is the catalyst prepared in Example 1.

[0077] Application Example 2

[0078] This application example provides a method for applying the supported low-noble metal content catalyst to the dehydrogenation of a liquid organic hydrogen storage carrier. The method comprises: after the reduction is completed, a dehydrogenation reaction is directly carried out in a fixed bed reactor, the reaction raw material is perhydrodibenzyltoluene (effective ingredient ≥ 98%), the reaction pressure is normal pressure, the reaction temperature is 270°C, and the liquid mass space velocity is 1h -1 The supported catalyst with low noble metal content is the catalyst prepared in Example 1.

[0079] Application Example 3

[0080] This application example provides a method for applying the supported low-noble metal content catalyst to the dehydrogenation of a liquid organic hydrogen storage carrier. The method comprises: after the reduction is completed, a dehydrogenation reaction is directly carried out in a fixed bed reactor, the reaction raw material is perhydrodibenzyltoluene (effective ingredient ≥ 98%), the reaction pressure is normal pressure, the reaction temperature is 350°C, and the liquid mass space velocity is 20h -1 The supported catalyst with low noble metal content is the catalyst prepared in Example 1.

[0081] Application Example 4

[0082] This application example is the same as application example 1 except that the supported low-noble metal content catalyst used is the catalyst prepared in example 2.

[0083] Application Example 5

[0084] This application example is the same as application example 1 except that the supported low-noble metal content catalyst used is the catalyst prepared in Example 3.

[0085] Application Example 6

[0086] This application example is the same as application example 1 except that the supported low-noble metal content catalyst used is the catalyst prepared in Example 4.

[0087] Application Example 7

[0088] This application example is the same as application example 1 except that the supported low-noble metal content catalyst used is the catalyst prepared in Example 5.

[0089] Application Example 8

[0090] This application example is the same as application example 1 except that the supported low-noble metal content catalyst used is the catalyst prepared in Example 6.

[0091] Application Comparative Example 1

[0092] This application example is the same as application example 1 except that the supported low-noble metal content catalyst used is the catalyst prepared in comparative example 1.

[0093] Application Comparative Example 2

[0094] This application example is the same as application example 1 except that the supported low-noble metal content catalyst used is the catalyst prepared in comparative example 2.

[0095] Application Comparative Example 3

[0096] This application example is the same as application example 1 except that the supported low-noble metal content catalyst used is the catalyst prepared in comparative example 3.

[0097] Test Method

[0098] A flow meter is used to monitor the real-time rate of hydrogen online.

[0099] Test Standards

[0100] Dehydrogenation degree = real-time hydrogen production rate / theoretical maximum hydrogen production rate

[0101] Theoretical maximum hydrogen production rate (mL / min) = raw material feed mass flow rate / raw material molar mass * 9 * 22.4 * 1000

[0102] Hydrogen space-time yield (g H2 / g 铂 / h) = hydrogen production rate / mass of platinum in the catalyst = liquid mass space velocity * dehydrogenation degree * 9 * 2 / molecular weight of perhydrodibenzyltoluene / platinum loading

[0103] The test results are shown in Table 1:

[0104] Table 1

[0105]

[0106]

[0107] The test results show that:

[0108] (1) It can be seen from Application Examples 1 and 4-5 that the present invention can achieve high-efficiency utilization of active components by regulating the impregnation depth and distribution uniformity of active components on the catalyst carrier. Under the condition of low noble metal active component content, the catalytic effect similar to that of high noble metal content is achieved, and the unit mass noble metal utilization rate is much higher than that of high noble metal content. At a reaction temperature of 290°C, the hydrogen space-time yield can reach 20h -1 above.

[0109] (2) It can be seen from Application Examples 1 and 2-3 that the supported low-noble metal content catalyst provided by the present invention retains the characteristic that the catalytic effect is affected by the reaction temperature, and it can maintain a good catalytic effect at 270°C to 350°C. The hydrogen space-time yield at 270°C is maintained at 12.7h -1 , up to 165.0h at 350℃ -1 .

[0110] (2) It can be seen from Application Examples 1 and Application Examples 6 to 8 that the present invention can achieve a better precious metal distribution effect by further using a rotary evaporator to quickly remove the impregnation solvent under negative pressure and low temperature conditions. After the solvent is quickly removed at low temperature, the precious metal agglomeration caused by the solvent effect during the evaporation process is avoided. When the solvent is not removed by rotary evaporation or the rotary evaporation temperature is too low, the solvent cannot be fully removed, and precious metal agglomeration occurs in the next drying procedure. The hydrogen space-time yield is reduced from 30.8h in Application Example 1 to 1.5h in Application Example 1. -1 Down to 15.7h in Application Example 6 -1 and 18.2h in Application Example 7 -1 When the rotary evaporation temperature is too high, the noble metals agglomerate during the rotary evaporation process, and the hydrogen space-time yield is reduced from 30.8h in Application Example 1 to -1Down to 11.8h in Application Example 8 -1 .

[0111] (3) It can be seen from Application Example 1 and Application Comparative Example 1 that the supported low-precious metal content catalyst provided by the present invention can achieve a similar dehydrogenation degree under the same catalyst loading amount and reaction conditions as the high-precious metal content dehydrogenation catalyst. The dehydrogenation degree decreases by only 4.3% from 45.2% in the comparative application example to 40.9% in Application Example 1. The hydrogen space-time yield, which represents the dehydrogenation efficiency per unit mass of precious metal, is significantly improved from 8.5h / min to 1.5h / min. -1 Improved to 30.8h -1 , significantly reducing the cost of dehydrogenation catalysts.

[0112] (4) It can be seen from Application Example 1 and Application Comparative Examples 2 to 3 that the present invention adjusts the impregnation depth of the active substance on the catalyst support surface by optimizing the impregnation time, so that the catalyst has a suitable active substance loading amount and improves the utilization rate of the active substance. When the impregnation time is too short, the impregnation is insufficient and the precursor solution is unevenly distributed on the catalyst surface. Finally, the active component Pt on the catalyst is seriously aggregated, and the hydrogen space-time yield is reduced from 30.8h in Application Example 1 to 40.8h in Application Example 1. -1 Reduced to 23.5h of Comparative Example 2 -1 When the impregnation time is too long and the impregnation depth is too deep, the utilization rate of the active material Pt inside the carrier is too low, and the hydrogen space-time yield is reduced from 30.8h in Application Example 1 to -1 Reduced to 21.3h of Comparative Example 3 -1 .

[0113] In summary, the present invention provides a supported catalyst with low precious metal content, which improves the hydrogen production efficiency per unit mass of precious metal by regulating the impregnation depth and distribution state of its active components through the preparation method. Compared with the high-content precious metal dehydrogenation catalyst, the low-loaded precious metal catalyst of the present invention can achieve a similar degree of dehydrogenation under the same catalyst loading and reaction conditions. In summary, the use of the low-loaded catalyst described in the present invention can significantly reduce the cost of the dehydrogenation catalyst.

[0114] 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 supported catalyst with low noble metal content, characterized in that: The supported catalyst with low noble metal content comprises a catalyst carrier and an active component, wherein the content of the active component is 0.2-0.4wt%, and the relative impregnation depth of the active component is 0.05-0.

16.

2. The supported low noble metal content catalyst according to claim 1, characterized in that: The active component includes platinum.

3. The supported low noble metal content catalyst according to claim 1 or 2, characterized in that: The catalyst carrier includes aluminum oxide, silicon oxide, activated carbon, zirconium oxide, titanium oxide or molecular sieve; Preferably, the particle size of the catalyst carrier is 2 to 4 mm; Preferably, the impregnation depth of the active component is 0.1 to 0.32 mm.

4. A method for preparing the supported low noble metal content catalyst according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: (1) Spraying the precursor solution of the active component uniformly on the surface of the catalyst support and impregnating it at room temperature; (2) rotary evaporating the impregnated catalyst support to remove the solvent to obtain a precursor support; (3) The precursor support is dried and calcined in sequence to obtain the supported low noble metal content catalyst.

5. The method according to claim 4, characterized in that The precursor solution is a mixed solution of a noble metal precursor dissolved in an organic solvent and pure water; Preferably, the noble metal precursor comprises chloroplatinic acid; Preferably, the organic solvent comprises ethanol; Preferably, the volume content of the organic solvent in the mixed solution is 5 to 80%; Preferably, the immersion time is 0.5 to 10 hours.

6. The method according to claim 4 or 5, characterized in that: The pressure of the rotary evaporation is -0.10 to -0.05 MPa; Preferably, the temperature of the rotary evaporation is 30 to 80°C; Preferably, the rotary evaporation time is 10 to 30 minutes.

7. The method according to any one of claims 4 to 6, characterized in that: The drying temperature is 100-120°C; Preferably, the drying time is 10 to 20 hours; Preferably, the calcination temperature is 400-700°C; Preferably, the calcination time is 3 to 6 hours.

8. The method according to any one of claims 4 to 7, characterized in that: The supported low-noble metal content 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 200-600°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 supported catalyst with low noble metal content according to any one of claims 1 to 3, characterized in that: The applications include dehydrogenation of liquid organic hydrogen storage carriers; Preferably, the liquid organic hydrogen storage carrier includes any one of perhydrodibenzyltoluene, perhydromonobenzyltoluene, methylcyclohexane, decahydronaphthalene or bicyclohexane, preferably perhydrodibenzyltoluene.

10. The use of the supported low noble metal content catalyst according to claim 9, characterized in that: The method for dehydrogenating the liquid organic hydrogen storage carrier comprises: Passing a liquid organic hydrogen storage carrier through a fixed bed reactor filled with the supported low-noble metal content catalyst according to claim 1 or 2 to carry out a catalytic dehydrogenation reaction to obtain a dehydrogenation product; Preferably, the temperature of the catalytic dehydrogenation reaction is 250-350°C; Preferably, the amount of the supported low-noble metal content catalyst is 5 to 100 g; Preferably, the mass space velocity of the liquid organic hydrogen storage carrier is 1 to 20 h -1 .

Images