CN111054384A

CN111054384A - Catalyst for organic liquid hydrogen storage material dehydrogenation and preparation method thereof

Info

Publication number: CN111054384A
Application number: CN201811201434.2A
Authority: CN
Inventors: 柯俊; 童凤丫; 孙清; 缪长喜
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2018-10-16
Filing date: 2018-10-16
Publication date: 2020-04-24
Anticipated expiration: 2038-10-16
Also published as: CN111054384B

Abstract

The invention discloses a catalyst for dehydrogenation reaction of an organic liquid hydrogen storage material and a preparation method thereof, which solve the problem that the catalyst in the prior art is easy to deactivate, and the catalyst comprises the following components in parts by weight: a) 0.1-5.5 parts of Pt-Cu nanoparticles or oxides thereof; b) 0.1-5.4 parts of element M or oxide thereof, wherein M is selected from at least one of Mg and In; c)0.1 to 7.5 parts of Mn-Zr oxide; d) 80-99 parts of carrier S, wherein S is at least one of alumina, silica and titanium oxide, and the zero-valent Pt content on the surface of the catalyst is 46-75%. The catalyst and the preparation method thereof have the advantage of difficult inactivation when used for dehydrogenation reaction of the organic liquid hydrogen storage material.

Description

Catalyst for organic liquid hydrogen storage material dehydrogenation and preparation method thereof

Technical Field

The invention discloses a catalyst for dehydrogenation reaction of an organic liquid hydrogen storage material with higher activity and a preparation method thereof.

Background

Hydrogen energy has been widely spotlighted as a representative of green sustainable new energy. In the beginning of the 21 st century, hydrogen energy development plans were made in china and the united states, japan, canada, european union, etc., and related studies were pursued. Hydrogen energy applications include hydrogen gas production, storage, transportation, and application links, where hydrogen energy storage is a key and difficult point. Hydrogen fuel vehicles are the main approach for hydrogen energy application, and the development of hydrogen storage technology suitable for hydrogen fuel vehicles is the premise of large-scale application of hydrogen energy.

At present, the hydrogen storage technology mainly comprises physical hydrogen storage, adsorption hydrogen storage and chemical hydrogen storage. Physical hydrogen storage technology has met the requirements of vehicles, but its high requirements on equipment and harsh operating conditions have made the contradiction between performance and efficiency of this technology increasingly prominent. Adsorption hydrogen storage and chemical hydrogen storage are the key points of the current research, and certain research results are obtained, but certain differences exist between the technical requirements of vehicle-mounted hydrogen storage. The organic liquid hydrogen storage technology (organic liquid mainly comprises methylcyclohexane, cyclohexane, tetrahydronaphthalene, decahydronaphthalene, perhydroazeethylcarbazole, perhydrocarbazole and the like) in chemical hydrogen storage realizes the storage of hydrogen energy through catalytic addition and dehydrogenation reversible reaction, the reaction in the process is reversible, reactant products can be recycled, and the hydrogen storage amount is relatively high (about 60-75 kg H)₂·m^-3The mass fraction is 6-8 percent), the method meets the indexes specified by the International energy agency and the United states department of energy (DOE), and the method can be used for long-distance transportation in the form of organic liquid or can solve the problem of uneven distribution of energy in areas, really meets the requirements of green chemistry, and has a strong application prospect.

The hydrogenation process and the dehydrogenation process exist simultaneously in the organic liquid hydrogen storage technology, the hydrogenation process is relatively simple, the technology is mature, and the dehydrogenation process is a strong endothermic and highly reversible reaction, so that the dehydrogenation reaction is favorably carried out at high temperature from the aspects of dynamics and thermodynamics, but the activity of the catalyst is reduced and even inactivated due to side reactions such as cracking, carbon deposition and the like which are easily generated at high temperature, and the dehydrogenation reaction is not favorably carried out.

Pt/Al is simple and cheap in preparation method₂O₃The catalyst is widely used as dehydrogenation catalyst of organic liquid hydrogen storage material, but the catalyst needs to be calcined at high temperature and reduced by hydrogen in the preparation process, because Pt and Al₂O₃The interaction between the Pt and the Pt belongs to weak interaction, and Pt atoms are easy to aggregate in the preparation processThe size is enlarged, eventually leading to a decrease in catalyst activity; in addition to Al₂O₃The weak acidity of the surface can quickly generate carbon deposit after the catalytic reaction is started, so that the activity of the catalyst is easy to reduce in the catalytic process, and therefore, the Pt/Al catalyst is prepared from Pt and Al₂O₃Is not an ideal dehydrogenation catalyst for the organic liquid hydrogen storage material, and the research on the dehydrogenation catalyst which is not suitable for deactivation is urgently needed. Since the dehydrogenation effect of Pt is the best among all metals, in the research of organic liquid dehydrogenation catalyst, the important point is to select proper auxiliary agent to change the carrier or regulate the surface property of the carrier, so as to play the role of regulating the size of Pt, the specific surface area of the carrier, the pH value of the carrier, etc. or generate other beneficial effects, so that the activity of the catalyst can be kept stable for a long time.

CN105102120A discloses a dehydrogenation catalyst for naphthenic hydrocarbons, which is prepared by adding Pt/Al₂O₃Group 3 metals are introduced into the catalyst as promoters. CN103443060B discloses a method for catalyzing dehydrogenation of saturated cyclic hydrocarbons and five-membered cyclic compounds with a Pt-Sn dehydrogenation catalyst.

The organic liquid dehydrogenation catalytic reaction is usually to convert at least one non-aromatic ring containing or not containing heteroatoms in the raw material into an aromatic ring or an aromatic heterocycle through dehydrogenation reaction, and the structural characteristics, the characteristics of thermodynamic data and the like determine that the organic liquid dehydrogenation catalytic reaction and the catalyst thereof are different from the dehydrogenation of low-carbon alkane, the dehydrogenation of alkyl aromatic hydrocarbon or other dehydrogenation reactions and the catalysts thereof. Therefore, the organic liquid dehydrogenation catalyst, particularly the auxiliary agent therein, needs to be finely designed and regulated, the catalyst and the preparation method thereof proposed by the invention are not reported in documents or patents, and the catalytic capability can keep better stability and play a good catalytic effect.

Disclosure of Invention

One of the technical problems to be solved by the invention is the problem that the organic liquid hydrogen storage material dehydrogenation catalyst is easy to deactivate in the prior art, and a novel catalyst for dehydrogenation reaction of the organic liquid hydrogen storage material is provided. The second technical problem to be solved by the present invention is to provide a method for preparing a catalyst corresponding to the first technical problem.

In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows:

a catalyst for dehydrogenation reaction of organic liquid hydrogen storage materials comprises the following components in parts by weight:

a) 0.1-5.5 parts of Pt-Cu nanoparticles or oxides thereof;

b) 0.1-5.4 parts of element M or oxide thereof, wherein M is selected from at least one of Mg and In;

c)0.1 to 7.5 parts of Mn-Zr oxide;

d) 80-99 parts of a carrier S, wherein S is at least one selected from alumina, silica and titanium oxide; in the X-ray photoelectron spectrum of the catalyst, the zero-valent Pt content on the surface of the catalyst is 46-75%.

In the above technical solution, preferably, the Pt — Cu nanoparticles or the oxides thereof in the component a) are 0.1 to 2.5 parts by weight.

In the technical scheme, the molar ratio of Cu to Pt in the component a) is preferably (0.05-0.9): 1.

In the technical scheme, more preferably, the molar ratio of Cu to Pt in the component a) is (0.1-0.6): 1.

In the above technical solution, preferably, the component b) is selected from Mg and In or mixed oxides thereof.

In the above technical scheme, preferably, the component b) contains 0.6 to 2.6 parts of the element M or the oxide thereof.

In the technical scheme, the preferable part of the Mn-Zr oxide is 1.2-4.8 parts by weight.

In the above technical scheme, preferably, in the component d), the molar ratio of Zr to Mn is (0.04-0.6): 1.

In the above technical solution, preferably, the carrier is selected from γ -Al₂O₃Or SiO₂One kind of (1).

In the above technical solution, more preferably, the carrier is selected from γ -Al₂O₃。

In the above technical solution, preferably, in the X-ray photoelectron spectroscopy, the zero-valent Pt content on the surface of the catalyst is 50% to 64%.

The method for measuring the zero-valent Pt content on the surface of the catalyst comprises the following steps of pre-reducing the catalyst in a hydrogen atmosphere at 350 ℃, then carrying out X-ray photoelectron spectroscopy on an X-ray photoelectron spectrometer by taking K α rays of Al as a light source, wherein the 4f peak area of Pt in the obtained X-ray photoelectron spectroscopy is recorded as S (Pt), the peak area at the position of 71.2eV binding energy is recorded as S (Pt0), and the calculation formula of the zero-valent Pt is as follows:

zero-valent Pt content-S (Pt0) ÷ S (Pt)

The catalyst surface here refers to the atoms on the catalyst within the depth of probing of the instrument in this test, which is usually expressed in terms of the inelastic mean free path, with the catalyst surface Pt having an inelastic mean free path of 1.6nm under the above test conditions.

To solve the second technical problem, the invention adopts the following technical scheme:

a method for preparing a catalyst for dehydrogenation of an organic liquid hydrogen storage material, which corresponds to one of the technical problems solved, comprising the steps of:

1) dissolving soluble compounds of Pt and Cu in water, adding a reducing agent, a nano-particle coating reagent and soluble halide, reacting, and treating to obtain Pt-Cu nano-particles;

2) dissolving soluble salts of Mn and Zr in water, adding a carrier S, adding ammonia water until the pH value is alkaline, and treating to obtain a catalyst precursor I;

3) dissolving soluble salt of the M element in water, adding the soluble salt into the catalyst precursor I, uniformly mixing, and treating to obtain a catalyst precursor II;

4) and dispersing the Pt-Cu nanoparticles obtained in the steps into ethanol, adding the Pt-Cu nanoparticles into a catalyst precursor II, uniformly mixing, volatilizing the solvent, drying and roasting to obtain the organic liquid hydrogen storage material dehydrogenation catalyst. Preferably, the preparation process also comprises the steps of dipping, drying and roasting;

the catalyst comprises the following components in parts by weight: a) 0.1-5.5 parts of Pt-Cu nanoparticles or oxides thereof; b) 0.1-5.4 parts of element M or oxide thereof, wherein M is selected from at least one of Mg and In; c)0.1 to 7.5 parts of Mn-Zr oxide; d) 80-99 parts of a carrier S, wherein S is at least one selected from alumina, silica and titanium oxide; in the X-ray photoelectron spectrum of the catalyst, the zero-valent Pt content on the surface of the catalyst is 46-75%.

In the above technical solution, preferably, the soluble salt of Pt is preferably one selected from chloroplatinic acid and potassium chloroplatinite, and the soluble salt of Mn, Zr, Mg, In element is preferably one selected from chloride or nitrate.

In the above technical solution, preferably, in step a), the reducing agent is selected from one of hydrazine hydrate or sodium borohydride, the coating agent is preferably polyvinylpyrrolidone, and the soluble halide is preferably selected from one of potassium chloride or potassium bromide.

In the technical scheme, preferably, the dipping temperature in the dipping process is 10-80 ℃, the dipping time is 1-24 hours, the drying temperature is 80-150 ℃, and the drying time is 4-24 hours. The roasting process is carried out at 450-650 ℃ for 4-24 hours.

The organic liquid hydrogen storage material dehydrogenation catalyst prepared by the method is subjected to activity evaluation in an isothermal fixed bed reactor, and the reaction conditions are as follows: the reaction pressure is 0-1 MPa, the temperature is 200-450 ℃, and the mass space velocity is 0.1-10 h^-1(ii) a The organic liquid hydrogen storage material is contacted with the catalyst to react to generate hydrogen and corresponding aromatic hydrocarbon.

In the above technical solution, preferably, the organic liquid hydrogen storage material is selected from at least one of methylcyclohexane, cyclohexane, tetrahydronaphthalene, decahydronaphthalene, perhydroazeethylcarbazole, and perhydrocarbazole.

In the above technical solution, preferably, the activation conditions before the catalyst reaction are as follows: the reduction temperature is 300-500 ℃, preferably 300-400 ℃, and the hydrogen flow rate in the reduction process is 100-500 mL/min^-1Preferably 200 to 400 mL/min^-1The reduction time is 2-8 h, preferably 3-6 h.

In the dehydrogenation catalysis process of the organic liquid hydrogen storage material, Pt is used as a single active component of the catalyst, the stability of the catalytic capability of the catalyst is limited by the electronic structure of the catalyst, and the catalyst is easy to inactivate. The invention adopts Pt-Cu nano particles or oxides thereof and Mn-Zr oxides, utilizes the synergistic effect of the Pt-Cu nano particles or oxides thereof and Mn, Zr, Mg and In elements, and adopts a corresponding catalyst preparation method to ensure that the catalyst provided by the invention is catalyzed In the dehydrogenation catalytic reaction of the organic liquid hydrogen storage material, has the advantage of difficult inactivation and produces better technical effect.

The invention is further illustrated by the following examples, but is not limited thereto.

Detailed Description

[ example 1 ]

192mg of potassium chloroplatinite, 23.7mg of copper chloride, 500mg of polyvinylpyrrolidone and 5.0g of potassium bromide are dissolved in 284mL of deionized water in a 500mL hydrothermal kettle and uniformly mixed, 16mL of hydrazine hydrate solution with the mass fraction of 85% is added, the mixture is reacted for 1h in a 160 ℃ oven, and after centrifugal separation and washing, Pt-Cu nano particles are obtained and are dispersed in ethanol.

193mg of manganese chloride and 49.4mg of zirconium nitrate are weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al is added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

138mg of magnesium nitrate and 43.4mg of indium nitrate were weighed and dissolved in 5mL of water, and 2.0g of the catalyst precursor I was added thereto with stirring, immersed at room temperature for 4 hours, dried in an oven at 90 ℃ for 4 hours, and then calcined in a muffle furnace at 450 ℃ for 4 hours to obtain a catalyst precursor II.

Adding the catalyst precursor II into ethanol dispersed with 13mg of Pt-Cu nanoparticles under stirring, stirring for 2h, drying in a 50 ℃ oven for 4h, and then placing in a muffle furnace to roast at 650 ℃ for 4h to obtain the catalyst.

Grinding the obtained catalyst into particles with the particle size of 12-20 meshes, and measuring the particle size by using an X-ray photoelectron spectrometer according to the methodThe zero-valent Pt content of the catalyst surface is measured by the method, the result is shown in the table 1, another 1.5g is mixed and diluted by a proper amount of 20-mesh quartz sand without catalytic activity and then is evaluated in an isothermal fixed bed reactor, and the flow rate is 300 mL/min before the evaluation^-1The catalyst is reduced by the hydrogen flow at normal pressure and 350 ℃ for 4h, and the temperature is reduced at normal pressure and 320 ℃ after the temperature is reduced, and the space velocity is 2.7h^-1The catalysts were evaluated under the conditions of (1) and the conversion rates at 1h and 55h of the catalytic reaction were recorded using methylcyclohexane as a representative raw material for hydrogen storage in the organic liquid, and the results are shown in table 1.

[ example 2 ]

192mg of potassium chloroplatinite, 7.9mg of copper chloride, 500mg of polyvinylpyrrolidone and 5.0g of potassium bromide are dissolved in 284mL of deionized water in a 500mL hydrothermal kettle and uniformly mixed, 16mL of hydrazine hydrate solution with the mass fraction of 85% is added, the mixture is reacted for 1h in a 160 ℃ oven, and after centrifugal separation and washing, Pt-Cu nano particles are obtained and are dispersed in ethanol.

The obtained catalyst is ground into particles with the particle size of 12-20 meshes, the method for testing the zero-valent Pt content on the surface of the catalyst is the same as that in example 1, 1.5g of the catalyst is mixed and diluted by a proper amount of 20-mesh quartz sand without catalytic activity and then is evaluated in an isothermal fixed bed reactor, hydrogen is used for reduction before evaluation, the reduction conditions and the evaluation conditions are the same as those in example 1, and the results are shown in Table 1.

[ example 3 ]

192mg of potassium chloroplatinite, 47.3mg of copper chloride, 500mg of polyvinylpyrrolidone and 5.0g of potassium bromide are dissolved in 284mL of deionized water in a 500mL hydrothermal kettle and uniformly mixed, 16mL of hydrazine hydrate solution with the mass fraction of 85% is added, the mixture is reacted for 1h in a 160 ℃ oven, and after centrifugal separation and washing, Pt-Cu nano particles are obtained and are dispersed in ethanol.

[ example 4 ]

192mg of potassium chloroplatinite, 3.9mg of copper chloride, 500mg of polyvinylpyrrolidone and 5.0g of potassium bromide are dissolved in 284mL of deionized water in a 500mL hydrothermal kettle and uniformly mixed, 16mL of hydrazine hydrate solution with the mass fraction of 85% is added, the mixture is reacted for 1h in a 160 ℃ oven, and after centrifugal separation and washing, Pt-Cu nano particles are obtained and are dispersed in ethanol.

[ example 5 ]

192mg of potassium chloroplatinite, 71mg of copper chloride, 500mg of polyvinylpyrrolidone and 5.0g of potassium bromide are dissolved in 284mL of deionized water in a 500mL hydrothermal kettle and uniformly mixed, 16mL of hydrazine hydrate solution with the mass fraction of 85% is added, the mixture is reacted for 1h in a 160 ℃ oven, and after centrifugal separation and washing, Pt-Cu nano particles are obtained and are dispersed in ethanol.

[ example 6 ]

The catalyst precursor II was added to ethanol in which 2.2mg of Pt-Cu nanoparticles were dispersed with stirring, stirred for 2 hours, dried in a 50 ℃ oven for 4 hours, and then calcined in a muffle furnace at 650 ℃ for 4 hours to obtain a catalyst.

[ example 7 ]

The catalyst precursor II was added to ethanol in which 26.1mg of Pt-Cu nanoparticles were dispersed with stirring, stirred for 2 hours, dried in a 50 ℃ oven for 4 hours, and then calcined in a muffle furnace at 650 ℃ for 4 hours to obtain a catalyst.

[ example 8 ]

The catalyst precursor II was added to ethanol in which 54.3mg of Pt-Cu nanoparticles were dispersed with stirring, stirred for 2 hours, dried in a 50 ℃ oven for 4 hours, and then calcined in a muffle furnace at 650 ℃ for 4 hours to obtain a catalyst.

[ example 9 ]

193mg of manganese chloride and 4 are weighed9.4mg of zirconium nitrate was dissolved in 250mL of deionized water, and 3.0g of γ -Al was added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

The catalyst precursor II was added to ethanol in which 59.8mg of Pt-Cu nanoparticles were dispersed with stirring, stirred for 2 hours, dried in a 50 ℃ oven for 4 hours, and then calcined in a muffle furnace at 650 ℃ for 4 hours to obtain a catalyst.

[ example 10 ]

275mg of magnesium nitrate was weighed and dissolved in 5mL of water, and 2.0g of the above catalyst precursor I was added thereto with stirring, immersed at room temperature for 4 hours, dried in an oven at 90 ℃ for 4 hours, and then calcined in a muffle furnace at 450 ℃ for 4 hours to obtain a catalyst precursor II.

[ example 11 ]

86.8mg of indium nitrate was weighed and dissolved in 5mL of water, and 2.0g of the catalyst precursor I was added thereto with stirring, immersed at room temperature for 4 hours, dried in an oven at 90 ℃ for 4 hours, and then calcined in a muffle furnace at 450 ℃ for 4 hours to obtain a catalyst precursor II.

[ example 12 ]

68.8mg of magnesium nitrate and 21.7mg of indium nitrate were weighed and dissolved in 5mL of water, and 2.0g of the above catalyst precursor I was added thereto with stirring, immersed at room temperature for 4 hours, dried in an oven at 90 ℃ for 4 hours, and then calcined in a muffle furnace at 450 ℃ for 4 hours to obtain a catalyst precursor II.

[ example 13 ]

298mg of magnesium nitrate and 94mg of indium nitrate were weighed and dissolved in 5mL of water, and 2.0g of the catalyst precursor I was added thereto with stirring, immersed at room temperature for 4 hours, dried in a 90 ℃ oven for 4 hours, and then calcined in a muffle furnace at 450 ℃ for 4 hours to obtain a catalyst precursor II.

[ example 14 ]

193mg of manganese chloride and 49.4mg of zirconium nitrate are weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al is added₂O₃The carrier is stirred for 1h, and then continuously stirredWhile stirring, aqueous ammonia was added dropwise until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

11.5mg of magnesium nitrate and 3.6mg of indium nitrate were weighed and dissolved in 5mL of water, and 2.0g of the catalyst precursor I was added thereto with stirring, immersed at room temperature for 4 hours, dried in an oven at 90 ℃ for 4 hours, and then calcined in a muffle furnace at 450 ℃ for 4 hours to obtain a catalyst precursor II.

[ example 15 ]

619mg of magnesium nitrate and 195mg of indium nitrate were weighed and dissolved in 5mL of water, and 2.0g of the catalyst precursor I was added thereto with stirring, immersed at room temperature for 4 hours, dried in an oven at 90 ℃ for 4 hours, and then calcined in a muffle furnace at 450 ℃ for 4 hours to obtain a catalyst precursor II.

[ example 16 ]

211mg of manganese chloride and 19.8mg of zirconium nitrate are weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al is added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

[ example 17 ]

156mg of manganese chloride and 108mg of zirconium nitrate are weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al is added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

[ example 18 ]

120mg of manganese chloride and 164mg of zirconium nitrate are weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al is added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

[ example 19 ]

77.1mg of manganese chloride and 19.8mg of zirconium nitrate were weighed, dissolved in 250mL of deionized water, and 3.0g of gamma-Al was added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. Aging the product for 2h, filtering, washing with 500mL of water for three times,after drying in an oven at 90 ℃ for 16h, the catalyst precursor I was calcined in a muffle furnace at 650 ℃ for 16 h.

[ example 20 ]

308mg of manganese chloride and 79.1mg of zirconium nitrate are weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al is added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

[ example 21 ]

6.4mg of manganese chloride and 1.7mg of zirconium nitrate were weighed, dissolved in 250mL of deionized water, and 3.0g of gamma-Al was added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

[ example 22 ]

482mg of manganese chloride and 124mg of zirconium nitrate were weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al was added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

[ example 23 ]

193mg of manganese chloride and 49.4mg of zirconium nitrate were weighed and dissolved in 250mL of deionized water, and 3.0g of SiO was added₂After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

[ example 24 ]

193mg of manganese chloride and 49.4mg of zirconium nitrate were weighed and dissolved in 250mL of deionized water, and 3.0g of TiO was added₂After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

Comparative example 1

27.8mg of potassium chloroplatinite was dissolved in 5mL of water, and 2.0g of gamma-Al was added under stirring₂O₃Adding the carrier into the solution, soaking the solution for 4 hours at room temperature, drying the solution for 4 hours in a 90 ℃ oven, and then putting the dried solution into a muffle furnace to roast the solution for 4 hours at 650 ℃ to obtain the catalyst.

Comparative example 2

25.3mg of potassium chloroplatinite, 8.3mg of copper chloride, 138mg of magnesium nitrate and 43.4mg of indium nitrate were weighed and dissolved in 5mL of water, 2.0g of the catalyst precursor I was added thereto with stirring, immersed at room temperature for 4 hours, dried in an oven at 90 ℃ for 4 hours, and then calcined in a muffle furnace at 650 ℃ for 4 hours to obtain a catalyst.

Comparative example 3

192mg of potassium chloroplatinite, 402mg of copper chloride, 500mg of polyvinylpyrrolidone and 5.0g of potassium bromide are dissolved in 284mL of deionized water in a 500mL hydrothermal kettle and uniformly mixed, 16mL of hydrazine hydrate solution with the mass fraction of 85% is added, the mixture is reacted for 1h in a 160 ℃ oven, and after centrifugal separation and washing, Pt-Cu nano particles are obtained and are dispersed in ethanol.

Comparative example 4

Dissolving 192mg of potassium chloroplatinite, 500mg of polyvinylpyrrolidone and 5.0g of potassium bromide in 284mL of deionized water in a 500mL hydrothermal kettle, uniformly mixing, adding 16mL of hydrazine hydrate solution with the mass fraction of 85%, reacting in a 160 ℃ oven for 1h, centrifugally separating, washing to obtain Pt-Cu nanoparticles, and dispersing the nanoparticles in ethanol.

Comparative example 5

Adding the catalyst precursor I into ethanol dispersed with 13mg of Pt-Cu nanoparticles under stirring, stirring for 2h, drying in a 50 ℃ oven for 4h, and then putting into a muffle furnace to roast at 650 ℃ for 4h to obtain the catalyst.

Comparative example 6

341mg of zirconium nitrate was weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al was added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

Comparative example 7

223mg of manganese chloride is weighed and dissolved in 250mL of deionized water, and 3.0g of gamma-Al is added₂O₃After stirring the support for 1h, ammonia was added dropwise with continued stirring until the pH was 8.5. And aging the product for 2h, performing suction filtration, washing with 500mL of water for three times, drying in a 90 ℃ oven for 16h, and then placing in a muffle furnace to calcine at 650 ℃ for 16h to obtain a catalyst precursor I.

Comparative example 8

TABLE 1

[ examples 27 to 33 ]

The performance of the catalyst prepared in example 1 for dehydrogenation of organic liquid hydrogen storage material was evaluated and the results are shown in table 2.

TABLE 2

Claims

1. The catalyst for the dehydrogenation reaction of the organic liquid hydrogen storage material comprises the following components in parts by weight:

a) 0.1-5.5 parts of Pt-Cu nanoparticles or oxides thereof;

c)0.1 to 7.5 parts of Mn-Zr oxide;

d) 80-99 parts of a carrier S, wherein S is at least one selected from alumina, silica and titanium oxide;

in the X-ray photoelectron spectrum of the catalyst, the zero-valent Pt content on the surface of the catalyst is 46-75%.

2. The catalyst for dehydrogenation of organic liquid hydrogen storage material according to claim 1, wherein the amount of Pt-Cu nanoparticles or their oxides in component a) is 0.1-2.5 parts by weight.

3. The catalyst for dehydrogenation of organic liquid hydrogen storage material according to claim 1, wherein the ratio of Cu to Pt in component a) is (0.05-0.9): 1, preferably (0.1-0.6): 1.

4. The catalyst for dehydrogenation of organic liquid hydrogen storage material according to claim 1, wherein the component b) contains 0.6-2.6 parts by weight of element M or its oxide, wherein M is selected from Mg and In or their mixed oxide.

5. The catalyst for dehydrogenation of organic liquid hydrogen storage material according to claim 1, wherein the Mn-Zr oxide is present in an amount of 1.2-4.8 parts by weight, and the ratio of Zr to Mn in component d) is (0.04-0.6): 1.

6. The organic liquid hydrogen storage material dehydrogenation catalyst of claim 1, wherein the support is S is γ -Al₂O₃Or SiO₂Preferably gamma-Al₂O₃。

7. The catalyst for dehydrogenation of organic liquid hydrogen storage materials according to claim 1, wherein the zero-valent Pt content of the catalyst surface is 50% to 64% in X-ray photoelectron spectroscopy.

8. A preparation method of an organic liquid hydrogen storage material dehydrogenation catalyst comprises the following steps:

3) dissolving soluble salt of the M element in water, adding the soluble salt into the catalyst precursor I, mixing and treating to obtain a catalyst precursor II;

4) dispersing the Pt-Cu nanoparticles obtained in the step into a solvent, adding the Pt-Cu nanoparticles into a catalyst precursor II, mixing and volatilizing the solvent, and processing to obtain an organic liquid hydrogen storage material dehydrogenation catalyst;

5) preferably, the preparation process also comprises the steps of dipping, drying and roasting;

9. A method for dehydrogenating an organic liquid hydrogen storage material comprises the following reaction conditions: the reaction pressure is 0-1 MPa, the temperature is 200-450 ℃, and the mass space velocity is 0.1-10 h^-1(ii) a Organic liquid hydrogen storage material and the catalysis of any of claims 1 to 7The contact reaction of the agents generates hydrogen and corresponding aromatic hydrocarbon.

10. The method of dehydrogenating an organic liquid hydrogen storage material according to claim 9, characterised in that the organic liquid hydrogen storage material is selected from at least one of methylcyclohexane, cyclohexane, tetrahydronaphthalene, decahydronaphthalene, perhydroazeethylcarbazole and perhydrocarbazole.