A single atom catalyst for dehydrogenation of liquid organic hydrogen storage carrier and its preparation method and application

Abstract

The present invention belongs to the field of catalysis. The present invention provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier, and a preparation method and application thereof, wherein the single-atom catalyst comprises a metal oxide carrier, and a noble metal single atom supported on the oxide carrier. The obtained single-atom catalyst is applied to the dehydrogenation reaction process of the liquid organic hydrogen storage carrier. Compared with metal particles, the single-atom catalyst exhibits better catalytic activity, effectively reduces the amount of noble metal used, and reduces the cost of the catalyst.

Description

Technical Field

[0001] The invention belongs to the field of catalysis and relates to a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier and a preparation method and application thereof. Background Art

[0002] As a promising renewable energy source, hydrogen energy has attracted more and more attention in dealing with the energy crisis. However, the safe storage and transportation of hydrogen have greatly restricted the development of hydrogen energy. Liquid organic hydrogen storage carrier (LOHC) is considered to be one of the key technologies that can effectively solve the above problems and is expected to achieve carbon neutrality within a few decades.

[0003] LOHC is a method of storing and transporting hydrogen, which uses the reversible reaction between unsaturated liquid organic matter such as certain olefins, alkynes or aromatic hydrocarbons and hydrogen to achieve hydrogen storage (chemical bonding) and release. The principle of this technology is to store hydrogen with the help of hydrogenation reaction and release hydrogen with the help of dehydrogenation reaction. Its characteristics are large hydrogen storage capacity, can be transported at normal temperature and pressure, and is convenient and safe.

[0004] Specifically, in LOHC, hydrogen is chemically bonded to an organic hydrocarbon carrier molecule (hydrogenation) and can be released in the reverse process (dehydrogenation). Common LOHC systems include methylcyclohexane (MCH), dibenzyltoluene (DBT) or decahydronaphthalene / naphthol, etc., which usually exist in liquid form under fairly loose standard conditions. Whether in hydrogenated or dehydrogenated form, it has similar physical properties to conventional fossil fuels (such as diesel).

[0005] LOHC thus offers many advantages. First, it can overcome the challenges of hydrogen transportation, using existing infrastructure to transport and store hydrogen in a more efficient, effective and safer way. LOHC is non-flammable and cheaper to transport than liquid hydrogen, which is explosive, easily evaporates, and requires expensive containers and new dedicated infrastructure. Second, LOHC is highly pure and non-toxic, and unlike ammonia, which has safety and environmental issues, it has at least the same reconversion cost and guaranteed purity. In addition, due to its physical similarity to conventional liquid fuels, LOHC has the potential to be easy to use and convenient to transport within existing infrastructure.

[0006] It can be seen that LOHC has the potential to be used to meet the global supply and demand of hydrogen, but its actual application and development are limited by the development of catalysts that are more suitable for large-scale production and application. Catalysts play an important role in the hydrogenation and dehydrogenation processes. They can not only reduce the reaction temperature, but also improve the reaction rate of chemical hydrogen storage technology. In recent years, the research on dehydrogenation catalysts of liquid organic hydrogen storage carriers has been mainly based on precious metal catalysts. However, the existing technology has problems such as high loading of precious metals, uneven distribution of active components on the carrier, and easy agglomeration during the reaction, resulting in low reaction activity.

[0007] Therefore, it is still necessary to develop a new solution to solve the problems of existing dehydrogenation catalysts, which is of great practical significance for the large-scale application and development of LOHC. Summary of the invention

[0008] In view of the problems existing in the prior art, the purpose of the present invention is to provide a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier and a preparation method and application thereof, wherein the single-atom catalyst comprises a metal oxide carrier and a noble metal single atom supported on the oxide carrier. When applied to the dehydrogenation reaction process of a liquid organic hydrogen storage carrier, the single-atom catalyst exhibits better catalytic activity than metal particles, and effectively reduces the amount of noble metal used and the cost of the catalyst.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier, wherein the single-atom catalyst comprises a metal oxide carrier, and a noble metal single atom supported on the oxide carrier.

[0011] The present invention constructs the single-atom catalyst and applies it to the dehydrogenation reaction process of a liquid organic hydrogen storage carrier. Compared with metal particles, the single-atom catalyst exhibits better catalytic activity and effectively reduces the amount of precious metals used, thereby reducing the cost of the catalyst.

[0012] The following are preferred technical solutions of the present invention, but are not intended to be limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0013] As a preferred technical solution of the present invention, the metal oxide carrier includes transition metal oxide and / or rare earth metal oxide.

[0014] Preferably, the metal oxide support includes any one of cerium oxide, titanium oxide or zirconium oxide, preferably cerium oxide.

[0015] The oxygen vacancies on the specific metal oxide carrier of the present invention are more likely to achieve single-atom loading, and compared with the inert carrier Al lacking single-atom anchoring sites, 2 O 3 , it is impossible to achieve single-atom loading through simple calcination treatment.

[0016] Preferably, the noble metal includes at least one of Pt, Pd or Rh. For example, typical but non-limiting combinations include a combination of Pt and Pd, a combination of Pt and Rh, or a combination of Pd and Rh.

[0017] Preferably, based on the mass of the metal oxide carrier as 100%, the loading amount of the noble metal single atom is 0.1% to 5%, for example, 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, 4.2%, 4.4%, 4.6%, 4.8% or 5%, etc., but are not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0018] In a second aspect, the present invention provides a method for preparing the single-atom catalyst according to the first aspect, the preparation method comprising:

[0019] The metal oxide support is mixed with a noble metal precursor and activated to obtain a single atom catalyst.

[0020] Compared with the prior art, the present invention can achieve single-atom dispersion of precious metals by a one-step impregnation method, significantly improving the utilization rate of active components, achieving low precious metal usage, while improving the reaction activity of the catalyst and effectively reducing the preparation cost of the catalyst.

[0021] As a preferred technical solution of the present invention, the mixing method includes performing initial wetness impregnation of the metal oxide support in a solution of a noble metal precursor.

[0022] Preferably, the noble metal precursor includes at least one of tetraamine platinum nitrate, chloroplatinic acid, palladium chloride, rhodium chloride, tetraamine palladium nitrate or rhodium nitrate.

[0023] As a preferred technical solution of the present invention, the method for preparing the metal oxide support comprises:

[0024] The metal oxide precursor is calcined to obtain a metal oxide carrier.

[0025] Preferably, the metal oxide precursor comprises a nitrate of the corresponding metal.

[0026] Preferably, the metal oxide precursor comprises cerium nitrate.

[0027] Preferably, the calcination temperature is 400-600°C, for example 400°C, 420°C, 440°C, 460°C, 480°C, 500°C, 520°C, 540°C, 560°C, 580°C or 600°C, and the calcination time is 3-5h, for example 3h, 3.2h, 3.4h, 3.6h, 3.8h, 4h, 4.2h, 4.4h, 4.6h, 4.8h or 5h, and is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0028] As a preferred technical solution of the present invention, drying and grinding treatments are first performed before the activation treatment.

[0029] Preferably, the temperature of the activation treatment is 300-600°C, for example 300°C, 320°C, 340°C, 360°C, 380°C, 400°C, 420°C, 440°C, 460°C, 480°C, 500°C, 520°C, 540°C, 560°C, 580°C or 600°C, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0030] Preferably, the activation treatment time is 120 to 240 min, for example 120 min, 140 min, 160 min, 180 min, 200 min, 220 min or 240 min, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0031] Preferably, the activation treatment is performed under an inert atmosphere.

[0032] Preferably, the pressure condition of the activation treatment is 0.1-0.4 MPa, for example, 0.1 MPa, 0.12 MPa, 0.14 MPa, 0.16 MPa, 0.18 MPa, 0.2 MPa, 0.22 MPa, 0.24 MPa, 0.26 MPa, 0.28 MPa, 0.3 MPa, 0.32 MPa, 0.34 MPa, 0.36 MPa, 0.38 MPa or 0.4 MPa, but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0033] The state of the noble metal loading is related to the calcination temperature and the reaction atmosphere during activation. In the preparation method described in the present invention, the noble metal single atom loading can be formed by performing an activation treatment at a specific temperature under an inert atmosphere, which simplifies the means of preparing single atoms.

[0034] As a preferred technical solution of the present invention, the preparation method comprises:

[0035] Putting a metal oxide precursor into a muffle furnace for calcination, wherein the metal oxide precursor includes a nitrate of a corresponding metal, wherein the nitrate includes cerium nitrate, and the temperature is controlled at 400 to 600° C. for 3 to 5 hours to obtain a metal oxide carrier;

[0036] Preparing a noble metal precursor as an impregnation solution, wherein the noble metal precursor includes at least one of tetraammine platinum nitrate or chloroplatinic acid;

[0037] Using the incipient wetness impregnation method, taking an appropriate amount of the impregnation solution, then adding the metal oxide support to the impregnation solution, stirring and standing, and then putting the solution into an oven for drying to obtain a catalyst precursor loaded with precious metals;

[0038] The obtained catalyst precursor loaded with precious metals is ground and then activated in a tube furnace at a controlled temperature of 300 to 600° C. with an inert atmosphere maintained at a pressure of 0.1 to 0.4 MPa for 120 to 240 minutes to obtain a single atom catalyst.

[0039] In a third aspect, the present invention provides an application of the single-atom catalyst described in the first aspect, wherein the application includes dehydrogenation of liquid organic hydrogen storage carriers and multiphase catalytic dehydrogenation.

[0040] As a preferred technical solution of the present invention, the method for dehydrogenating the liquid organic hydrogen storage carrier comprises:

[0041] The liquid organic hydrogen storage carrier is mixed with the single atom catalyst described in the first aspect to carry out a catalytic dehydrogenation reaction to obtain a dehydrogenation product.

[0042] As a preferred technical solution of the present invention, the molar amount of the noble metal single atom in the single atom catalyst accounts for 0.01% to 0.1% of the molar amount of the liquid organic hydrogen storage carrier, for example, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09% or 0.1%, etc., but is not limited to the listed values, and other unlisted values ​​within the above numerical range are equally applicable.

[0043] Preferably, the temperature of the catalytic dehydrogenation reaction is 200-400°C, for example, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C, 340°C, 360°C, 380°C or 400°C, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0044] Preferably, the catalytic dehydrogenation reaction time is 1 to 5 h, for example, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h or 5 h, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0045] Preferably, the catalytic dehydrogenation reaction is carried out under an inert atmosphere.

[0046] Preferably, the pressure condition of the catalytic dehydrogenation reaction is 0.1-1 MPa, for example, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa or 1 MPa, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0047] Preferably, the liquid organic hydrogen storage carrier comprises dibenzyltoluene.

[0048] It should be noted that the single-atom catalyst obtained in the present invention is not limited to being applicable only to dibenzyltoluene. Catalysts for dehydrogenation of aromatic rings are common. The more benzene rings there are, the more difficult it is to dehydrogenate. Therefore, the single-atom catalyst obtained in the present invention is applicable to dibenzyltoluene, which also means that it is compatible with other low-benzene ring organic liquids. Therefore, common organic liquids such as methylcyclohexane, decahydronaphthalene, etc. can use the single-atom catalyst obtained in the present invention to dehydrogenate liquid organic hydrogen storage carriers.

[0049] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0050] The present invention constructs the single-atom catalyst and applies it to the dehydrogenation reaction process of a liquid organic hydrogen storage carrier. Compared with metal particles, the single-atom catalyst exhibits better catalytic activity and effectively reduces the amount of precious metals used, thereby reducing the cost of the catalyst.

[0051] In particular, when the obtained single-atom catalyst is applied to the dehydrogenation reaction of fully hydrogenated dibenzyltoluene, it is very different from the classic Pt / Al 2 O 3 Compared with the catalyst, the dehydrogenation degree of the single atom catalyst of the present invention is comparable to that of the catalyst, but the amount of precious metal used is correspondingly reduced, the utilization rate of the active component is improved, and the cost of the catalyst is reduced. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0053] It should be clear to those skilled in the art that the embodiments are only intended to help understand the present invention and should not be considered as specific limitations of the present invention.

[0054] Example 1

[0055] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier, and the preparation method of the single-atom catalyst includes:

[0056] The metal oxide precursor cerium nitrate is placed in a muffle furnace for calcination at 600°C for 2 hours to obtain a metal oxide carrier;

[0057] The noble metal precursor chloroplatinic acid is prepared as an impregnation solution;

[0058] Using the incipient wetness impregnation method, taking an appropriate amount of the impregnation solution, then adding the metal oxide support to the impregnation solution, stirring evenly and standing for 12 hours, and then placing in an oven at 120° C. for drying for 12 hours to obtain a catalyst precursor loaded with precious metals;

[0059] The catalyst precursor loaded with precious metals was ground and activated in a tube furnace at a controlled temperature of 600 °C. 2 The process was carried out for 180 min under the condition that the atmosphere was maintained at a pressure of 0.25 MPa, and a single-atom catalyst with a single-atom Pt loading of 0.5% was obtained.

[0060] Example 2

[0061] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst is exactly the same as that of Example 1, except that the activation treatment temperature is adjusted from 600° C. to 300° C.

[0062] Example 3

[0063] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst is exactly the same as that of Example 1, except that the activation treatment temperature is adjusted from 600° C. to 400° C.

[0064] Example 4

[0065] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst is exactly the same as that of Example 1, except that the activation treatment temperature is adjusted from 600° C. to 500° C.

[0066] Example 5

[0067] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst is exactly the same as that of Example 1, except that the activation treatment temperature is adjusted from 600° C. to 650° C.

[0068] Example 6

[0069] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst is exactly the same as that of Example 1, except that the mass concentration of the precious metal precursor is adjusted so that the single-atom Pt loading in the obtained single-atom catalyst is adjusted from 0.5% to 0.3%.

[0070] Example 7

[0071] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst is exactly the same as that of Example 1, except that the mass concentration of the precious metal precursor is adjusted so that the single-atom Pt loading in the obtained single-atom catalyst is adjusted from 0.5% to 0.1%.

[0072] Example 8

[0073] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst is exactly the same as that of Example 1, except that the mass concentration of the precious metal precursor is adjusted so that the single-atom Pt loading in the obtained single-atom catalyst is adjusted from 0.5% to 1%.

[0074] Example 9

[0075] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst includes adjusting the metal oxide carrier so that the catalyst carrier in the obtained single-atom catalyst is composed of CeO 2 Adjusted to ZrO 2 Except for this, other conditions are exactly the same as those in Example 1.

[0076] Example 10

[0077] This embodiment provides a single-atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier. The preparation method of the single-atom catalyst includes adjusting the metal oxide carrier so that the catalyst carrier in the obtained single-atom catalyst is composed of CeO 2 Adjusted to TiO 2 Except for this, other conditions are exactly the same as those in Example 1.

[0078] Comparative Example 1

[0079] This comparative example provides a catalyst, and the activation treatment of the preparation method of the catalyst is:

[0080] The obtained catalyst precursor loaded with precious metals was ground and then activated in a tube furnace at a controlled temperature of 400°C with pure hydrogen (H 2) and maintaining a pressure of 0.25 MPa for 60 min to obtain a catalyst loaded with aggregated Pt. Except for the above, other conditions are exactly the same as those in Example 1.

[0081] Control group 1

[0082] This control group provides a catalyst, and the preparation method of the catalyst comprises: using the incipient wetness impregnation method to achieve 2 O 3 Pt was impregnated on the carrier, and the Pt loading was controlled to be 1 wt.%, and the catalyst obtained by impregnation was activated in a tube furnace under the same activation conditions as in Comparative Example 1, thereby obtaining 1Pt / Al 2 O 3 catalyst.

[0083] Application Example 1

[0084] This application example provides a method for dehydrogenating a liquid organic hydrogen storage carrier, the method comprising:

[0085] 0.8 g of the catalyst obtained in Example 1 was placed in a batch reactor containing 15 g of a liquid organic hydrogen storage carrier, fully hydrogenated dibenzyltoluene, and the molar amount of the noble metal in the catalyst was controlled to account for 0.037% of the molar amount of the liquid organic hydrogen storage carrier. Nitrogen was first introduced to replace the gas in the reaction system. After the air was evacuated, the gas pressure was maintained at normal pressure 0.1 MPa. A program temperature controller was used for control. After reaching the set temperature of 290° C., the dehydrogenation reaction timing was started. The reaction was stopped after 3 hours of timing. After cooling to room temperature, the liquid phase product was taken for analysis. The analytical instrument was detected online by a chromatogram with a TCD detector to obtain the data of the dehydrogenation product.

[0086] Application Example 2-10

[0087] Application Examples 2-10 respectively provide a method for dehydrogenating a liquid organic hydrogen storage carrier, wherein the catalysts of Examples 2-10 are used instead of the catalyst of Example 1, and the amount of the catalyst is adjusted to control the molar amount of the precious metal in the catalyst to 0.037% of the molar amount of the liquid organic hydrogen storage carrier, which is consistent with Application Example 1. Except for the above, other conditions are exactly the same as those of Application Example 1.

[0088] Comparative application example 1

[0089] This comparative application example provides a method for dehydrogenating a liquid organic hydrogen storage carrier, wherein the catalyst of comparative example 1 is used instead of the catalyst of example 1, and the amount of the catalyst is adjusted to control the molar amount of the precious metal in the catalyst to account for 0.037% of the molar amount of the liquid organic hydrogen storage carrier to remain consistent with application example 1. Except for the above, other conditions are exactly the same as those of application example 1.

[0090] Comparative Application Example 2

[0091] This comparative application example provides a method for dehydrogenating a liquid organic hydrogen storage carrier, wherein the catalyst of the control group 1 is used to replace the catalyst of Example 1, and the amount of the catalyst is kept unchanged at 0.8 g, so that the molar amount of the precious metal in the catalyst accounts for 0.075% of the molar amount of the liquid organic hydrogen storage carrier. Except for the above, other conditions are exactly the same as those of Application Example 1.

[0092] The dehydrogenation reaction results of the relevant catalysts are shown in Table 1 below.

[0093] Table 1

[0094] Group catalyst Catalyst No. Dehydrogenation degree Application Example 1 Example 1 <![CDATA[0.5Pt / CeO 2 -600N]]> 81.3％ Application Example 2 Example 2 <![CDATA[0.5Pt / CeO 2 -300N]]> 54.3％ Application Example 3 Example 3 <![CDATA[0.5Pt / CeO 2 -400N]]> 66.8％ Application Example 4 Example 4 <![CDATA[0.5Pt / CeO 2 -500N]]> 78.1％ Application Example 5 Example 5 <![CDATA[0.5Pt / CeO 2 -650N]]> 72.5％ Application Example 6 Example 6 <![CDATA[0.3Pt / CeO 2 -600N]]> 55.2％ Application Example 7 Example 7 <![CDATA[0.1Pt / CeO 2 -600N]]> 51.3％ Application Example 8 Example 8 <![CDATA[1Pt / CeO 2 -600N]]> 59.2％ Application Example 9 Example 9 <![CDATA[0.5Pt / ZrO 2 -600N]]> 62.8％ Application Example 10 Example 10 <![CDATA[0.5Pt / TiO 2 -600N]]> 80.7％ Comparative application example 1 Comparative Example 1 <![CDATA[0.5Pt / CeO 2 -H 2 ]]> 34.5％ Comparative Application Example 2 Control group 1 <![CDATA[1Pt / Al 2 THE 3 ]]> 76.4％

[0095] As can be seen from Table 1, in an intermittent reactor, the reaction temperature was 290°C for 3 hours. By comparing Application Example 1 with Comparative Application Example 1, it can be seen that Application Example 1 has significant dehydrogenation activity, which also shows that the state of the metal species determines the dehydrogenation activity: the dehydrogenation ability of a single atom is better than that of an aggregated metal cluster; and Application Examples 1-5 investigated the effect of the activation treatment temperature on the reaction activity. The high or low activation temperature affects the distribution ability of a single atom, and there is an optimal activation temperature. At a suitable activation temperature, it is beneficial to disperse the metal species at the single-atom level, but too low a reaction temperature leads to insufficient dispersion, while a higher reaction temperature easily leads to aggregation of active components; Application Examples 6-8 examine the effect of the amount of precious metal on the dehydrogenation reaction activity, and the metal loading also has an optimal value: low metal amounts are insufficient for the activation of reactants due to the excessive dispersion of their active sites, while higher metal amounts restrict the dispersion of single atoms to a certain extent; Application Example 1 is compared with Application Examples 8-9, and by examining the effect of different oxide carriers on the dehydrogenation activity, it is found that this scheme is applicable to different oxide carriers and has high dehydrogenation activity; compared with Control Group 1 (classic Pt / Al 2 O 3 ) catalysts, the dehydrogenation degree of the single-atom catalyst of the present invention is comparable to that of the conventional catalysts, but the amount of precious metals used is correspondingly reduced, the utilization rate of the active components is improved, and the cost of the catalyst is reduced.

[0096] The present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0097] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0098] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0099] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A single atom catalyst for dehydrogenation of a liquid organic hydrogen storage carrier, characterized in that: It includes a metal oxide carrier, and a noble metal single atom loaded on the oxide carrier; the metal oxide carrier includes cerium oxide; based on the mass of the metal oxide carrier being 100%, the loading amount of the noble metal single atom is 0.5% to 0.8%; The single atom catalyst is prepared according to the following preparation method, which consists of the following steps: The noble metal precursor is prepared as an impregnation solution; an initial wetness impregnation method is adopted to take an appropriate amount of the impregnation solution, and then the metal oxide carrier is added to the impregnation solution, stirred and allowed to stand, and then placed in an oven for drying to obtain a catalyst precursor loaded with the noble metal; the obtained catalyst precursor loaded with the noble metal is ground and then activated in a tubular furnace, the temperature is controlled to be 580-600°C, and an inert atmosphere is maintained under a pressure of 0.12-0.4MPa for 120-240min to obtain a single atom catalyst.

2. The single atom catalyst according to claim 1, characterized in that The noble metal includes at least one of Pt, Pd or Rh.

3. A method for preparing the single atom catalyst according to claim 1, characterized in that: The preparation method comprises: The noble metal precursor is prepared as an impregnation solution; an initial wetness impregnation method is adopted to take an appropriate amount of the impregnation solution, and then the metal oxide carrier is added to the impregnation solution, stirred and allowed to stand, and then placed in an oven for drying to obtain a catalyst precursor loaded with the noble metal; the obtained catalyst precursor loaded with the noble metal is ground and then activated in a tubular furnace, the temperature is controlled to be 580-600°C, and an inert atmosphere is maintained under a pressure of 0.12-0.4MPa for 120-240min to obtain a single atom catalyst.

4. The method for preparing a single atom catalyst according to claim 3, characterized in that: The noble metal precursor includes at least one of tetraammine platinum nitrate or chloroplatinic acid.

5. The method for preparing a single atom catalyst according to claim 3, characterized in that: The method for preparing the metal oxide support comprises: The metal oxide precursor is calcined to obtain a metal oxide carrier.

6. The method for preparing a single atom catalyst according to claim 5, characterized in that: The metal oxide precursor includes a nitrate of a corresponding metal.

7. The method for preparing a single atom catalyst according to claim 5, characterized in that: The calcination temperature is 400-600° C. and the calcination time is 3-5 hours.

8. The method for preparing a single atom catalyst according to claim 3, characterized in that: The preparation method comprises: Putting a metal oxide precursor into a muffle furnace for calcination, wherein the metal oxide precursor includes a nitrate of a corresponding metal, wherein the nitrate includes cerium nitrate, and the temperature is controlled at 400-600° C. for 3-5 hours to obtain a metal oxide carrier; Preparing a noble metal precursor as an impregnation solution, wherein the noble metal precursor includes at least one of tetraammine platinum nitrate or chloroplatinic acid; Using the incipient wetness impregnation method, taking an appropriate amount of the impregnation solution, then adding the metal oxide support to the impregnation solution, stirring and standing, and then putting the solution into an oven for drying to obtain a catalyst precursor loaded with precious metals; The obtained catalyst precursor loaded with precious metals is ground and then activated using a tubular furnace. The temperature is controlled at 580-600°C and the inert atmosphere is maintained at a pressure of 0.12-0.4 MPa for 120-240 minutes to obtain a single atom catalyst.

9. Use of the single atom 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 single atom catalyst according to claim 9, characterized in that: The method for dehydrogenating the liquid organic hydrogen storage carrier comprises: The liquid organic hydrogen storage carrier is mixed with the single atom catalyst according to claim 1 or 2, and a catalytic dehydrogenation reaction is carried out to obtain a dehydrogenation product.

11. The use of the single atom catalyst according to claim 10, characterized in that: The molar amount of the noble metal single atom in the single atom catalyst accounts for 0.01% to 0.1% of the molar amount of the liquid organic hydrogen storage carrier.

12. The use of the single atom catalyst according to claim 10, characterized in that: The temperature of the catalytic dehydrogenation reaction is 200-400°C.

13. The use of the single atom catalyst according to claim 10, characterized in that: The catalytic dehydrogenation reaction time is 1 to 5 hours.

14. The use of the single atom catalyst according to claim 10, characterized in that: The catalytic dehydrogenation reaction is carried out under an inert atmosphere.

15. The use of the single atom catalyst according to claim 10, characterized in that: The pressure condition of the catalytic dehydrogenation reaction is 0.1~1MPa.

16. The use of the single atom catalyst according to claim 10, characterized in that: The liquid organic hydrogen storage carrier includes dibenzyltoluene.