Preparation method and application of nickel-based catalyst for organic liquid hydrogen storage

Abstract

The invention is applicable to the technical field of hydrogen storage, and provides a preparation method of a nickel-based catalyst for organic liquid hydrogen storage, which comprises the following steps: simultaneously dropwise adding a metal salt solution of nickel and a precipitation solution into a carrier suspension for precipitation to obtain a catalyst precursor suspension; wherein the precipitation solution is an alkali solution; aging and filtering the catalyst precursor suspension to obtain a catalyst precursor, and washing, drying and calcining the catalyst precursor to obtain a nickel-based catalyst; grinding the obtained nickel-based catalyst into powder, fully mixing in deionized water, dropwise adding a small amount of noble metal precursor solution, and then stirring and evaporating to dryness; the method is simple in preparation process, the active metal in the prepared catalyst is uniformly dispersed and has good synergism with the noble metal, and the nickel-based catalyst can be used for hydrogenation reaction of hydrogen storage organic liquids such as N-ethyl carbazole, dibenzyl toluene, benzyl toluene, toluene, decahydronaphthalene and biphenyl and has excellent hydrogenation performance.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen storage, and in particular relates to a preparation method and application of a nickel-based catalyst for organic liquid hydrogen storage. Background Art

[0002] As a clean and renewable energy source, hydrogen energy has the remarkable characteristics of high energy density, zero carbon emissions and diversified sources, making it an efficient energy carrier to meet future energy challenges. The unique advantages of hydrogen energy lie in its wide application potential and environmental friendliness, especially in mitigating global warming and reducing greenhouse gas emissions.

[0003] The hydrogen energy industry chain can be divided into three key parts: hydrogen production, hydrogen storage and hydrogen use. Each link plays an important role in the process of realizing the hydrogen economy. First of all, the hydrogen production link involves the production of hydrogen, which is mainly achieved through water electrolysis, natural gas reforming, coal gasification and other methods. Although hydrogen production technology continues to advance, how to produce hydrogen in a more economical and environmentally friendly way is still an important research direction.

[0004] However, the main bottleneck restricting the development of the "hydrogen economy" is the hydrogen storage link. The storage and transportation of hydrogen face many challenges, which directly affect the economic and practical application of hydrogen energy. The safety of hydrogen is an important consideration because hydrogen is highly flammable and has high diffusivity, requiring strict safety measures to be taken during storage and transportation. The low density of hydrogen requires a larger volume or higher pressure for its storage, which increases the cost and complexity of hydrogen storage equipment. In addition, the transportation cost of hydrogen is also high because specially designed transportation facilities are required to cope with the high pressure or low temperature state of hydrogen. Another challenge is the vaporization loss of hydrogen. Since hydrogen is easily converted from liquid to gas during storage and transportation, this loss will lead to a reduction in the amount of hydrogen in actual use, further increasing costs. Due to the above problems, the economic and feasibility of hydrogen storage technology are severely restricted.

[0005] Therefore, the development of safe and efficient hydrogen storage materials has become the key to promoting the development of the hydrogen economy. Efficient hydrogen storage materials must not only meet safety requirements, but also have high hydrogen storage capacity and low cost. Current research is mainly focused on improving the performance of hydrogen storage materials, such as increasing hydrogen storage density, reducing energy consumption during hydrogen storage and transportation, and improving the recycling capacity of materials. New hydrogen storage materials and technologies, such as metal hydrides, chemical hydrides, and liquid organic hydrogen carriers, are being actively developed to solve problems in existing hydrogen storage technologies and promote the widespread application of hydrogen energy.

[0006] At present, the diversity of hydrogen storage technologies allows us to choose different methods to meet different needs. These hydrogen storage methods can be roughly divided into two categories: physical hydrogen storage and chemical hydrogen storage.

[0007] Physical hydrogen storage includes high-pressure gas storage, liquid hydrogen storage, and solid storage of hydrogen. High-pressure gas storage is to compress hydrogen into a high-pressure container. Although this method is relatively mature, its high energy consumption and equipment costs are still significant challenges. Liquid hydrogen storage liquefies hydrogen by cooling it to extremely low temperatures. This method can greatly increase the volume density of hydrogen storage, but the cost of cooling and insulation is extremely high. Solid hydrogen storage technology stores hydrogen through materials such as hydrides and chemical hydrides. Although it is safer, the cost of these materials and hydrogen storage efficiency need to be further optimized.

[0008] Chemical hydrogen storage involves storing hydrogen through chemical reactions, among which liquid organic hydride hydrogen storage technology has received widespread attention in recent years. This technology utilizes the catalytic addition and reversible dehydrogenation reactions between unsaturated aromatic hydrocarbons and hydrides (such as cycloalkanes) to achieve hydrogen storage. This method has significant advantages such as large hydrogen storage capacity, high energy density, and convenient liquid storage and transportation. During the hydrogen storage process, hydrogen forms hydrides with unsaturated aromatic hydrocarbons through catalytic hydrogenation reactions, and releases hydrogen through dehydrogenation reactions when needed. Since the reaction process is reversible, the main structure of the hydrogen storage will not be destroyed, the reaction products can be recycled, and the hydrogen reserves are relatively high, usually 60 to 75 kgH2 / m 3 , with a mass fraction of 6-8%. In addition, liquid organic hydride can be used in long-distance transportation, which helps to solve the problem of uneven regional distribution of energy.

[0009] The process of organic liquid dehydrogenation by reversible dehydrogenation reaction is closely related to high-activity catalysts. Precious metal catalysts have high catalytic activity and excellent selectivity, and play an important role in the field of catalytic hydrogenation. However, precious metal resources are limited, expensive, and cannot be used on a large scale. Non-precious metal nickel-based catalysts have high thermal stability and are selective for hydrogen, and are favored in non-precious metal catalyst catalytic hydrogenation. However, on the other hand, there are also some problems in the research and application of nickel-based catalysts, such as the catalyst is prone to carbon deposition during the reaction, causing deactivation, and poor stability at high temperatures. Summary of the invention

[0010] The purpose of the embodiments of the present invention is to provide a method for preparing a nickel-based catalyst for hydrogen storage in organic liquid and its application, aiming to solve the problems raised in the above-mentioned background technology.

[0011] The embodiment of the present invention is achieved by a method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid, comprising the following steps:

[0012] Step 1: simultaneously adding a nickel metal salt solution and a precipitate solution to a carrier suspension to perform precipitation, thereby obtaining a catalyst precursor suspension; wherein the precipitate solution is an alkaline solution;

[0013] Step 2: aging and filtering the catalyst precursor suspension to obtain a catalyst precursor, and washing, drying and calcining the catalyst precursor to obtain a nickel-based catalyst;

[0014] Step 3: Grind the obtained nickel-based catalyst into powder, fully mix it in deionized water, drop a small amount of precious metal precursor solution into it, and then stir and evaporate to dryness.

[0015] In a further technical solution, the nickel metal salt solution is prepared by mixing nickel salt and deionized water; the precipitate is prepared by mixing alkali and deionized water; the molar concentration of the active metal salt in the metal salt solution is 0.01 to 5 mol / L; the molar concentration of the alkali in the precipitate is 0.01 to 5 mol / L.

[0016] In a further technical solution, the nickel metal salt is one or more of nickel nitrate, acetate, halide and sulfate.

[0017] In a further technical solution, the alkali is one or more of sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, ammonia water, sodium bicarbonate, potassium bicarbonate and ammonium bicarbonate.

[0018] According to a further technical solution, the carrier suspension is a mixture of a carrier and deionized water. A uniformly mixed carrier suspension can be formed by dispersing an appropriate amount of the carrier in deionized water and continuously stirring. The carrier is one or more of aluminum oxide, magnesium oxide, manganese oxide, silicon oxide and activated carbon. The volume ratio of the carrier to deionized water is 0.1:1 to 10:1.

[0019] In a further technical solution, the noble metal is one or more of platinum, rhodium, ruthenium and palladium; and the noble metal precursor solution is one or more of platinum chloride, rhodium chloride, ruthenium chloride and palladium chloride.

[0020] According to a further technical solution, in step 1, the temperature during the precipitation process is controlled at -20 to 80°C; and the pH of the system is controlled at 6 to 10 during the precipitation process.

[0021] According to a further technical solution, in step 2, the aging time of the catalyst precursor suspension is 0 to 50 hours, the temperature during the aging process is controlled at -20 to 80°C, and the pH is controlled at 6 to 10.

[0022] A further technical solution is that in step 2, the standard for washing completion is that the pH value of the last washing solution is between 7 and 8; drying can be carried out under vacuum conditions, air atmosphere and inert atmosphere, the drying temperature is 20 to 200°C, and the drying time is 1 to 100 hours; calcination can be carried out under vacuum conditions, air atmosphere and inert atmosphere, the calcination temperature is 200 to 800°C, and the calcination time is 1 to 100 hours.

[0023] According to a further technical solution, in step 3, the temperature of stirring and evaporating to dryness is controlled at 40-90°C.

[0024] Another purpose of an embodiment of the present invention is to provide an application of a nickel-based catalyst for hydrogen storage in an organic liquid. The nickel-based catalyst prepared by the above method is applied to a hydrogenation reaction of a catalytic hydrogen storage organic liquid.

[0025] In a further technical solution, the hydrogen storage organic liquid is one or more of benzyltoluene, dibenzyltoluene, toluene, benzene, quinoline, carbazole and N-ethylcarbazole, but is not limited thereto.

[0026] According to a further technical solution, the temperature of the hydrogenation reaction is 100 to 500° C., and the pressure of the hydrogenation reaction is 1 to 10 MPa.

[0027] According to a further technical solution, the nickel-based catalyst needs to be placed in a reducing atmosphere for a reduction reaction before use, that is, before the catalytic hydrogenation reaction; wherein the reducing atmosphere can be hydrogen or diluted hydrogen; the temperature of the reduction reaction is 200 to 800° C., and the time of the reduction reaction is 1 to 100 hours.

[0028] The embodiments of the present invention provide a method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid and its application. The method has a simple preparation process, and the active metal in the prepared catalyst is evenly dispersed and has good synergy with the precious metal. The nickel-based catalyst can be used for the hydrogenation reaction of hydrogen storage organic liquids such as N-ethylcarbazole, dibenzyltoluene, benzyltoluene, toluene, decalin, biphenyl, etc., and has excellent hydrogenation performance. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0031] An embodiment of the present invention provides a method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid, comprising the following steps:

[0032] Step 1: simultaneously adding a nickel metal salt solution and a precipitate solution to a carrier suspension to perform precipitation, thereby obtaining a catalyst precursor suspension; wherein the precipitate solution is an alkaline solution;

[0033] Step 2: aging and filtering the catalyst precursor suspension to obtain a catalyst precursor, and washing, drying and calcining the catalyst precursor to obtain a nickel-based catalyst;

[0034] Step 3: Grind the obtained nickel-based catalyst into powder, fully mix it in deionized water, drop a small amount of precious metal precursor solution into it, and then stir and evaporate to dryness.

[0035] As a preferred embodiment of the present invention, the nickel metal salt solution is prepared by mixing nickel salt and deionized water; the precipitate is prepared by mixing alkali and deionized water; the molar concentration of the active metal salt in the metal salt solution is 0.01 to 5 mol / L, preferably 0.1 to 4 mol / L; the molar concentration of the alkali in the precipitate is 0.01 to 5 mol / L, preferably 0.1 to 4 mol / L.

[0036] As a preferred embodiment of the present invention, the nickel metal salt is one or more of nickel nitrate, acetate, halide and sulfate.

[0037] As a preferred embodiment of the present invention, the alkali is one or more of sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, ammonia water, sodium bicarbonate, potassium bicarbonate and ammonium bicarbonate.

[0038] As a preferred embodiment of the present invention, the carrier suspension is a mixture of a carrier and deionized water. By dispersing an appropriate amount of the carrier in the deionized water and continuously stirring, a uniformly mixed carrier suspension can be formed; the carrier is one or more of aluminum oxide, magnesium oxide, manganese oxide, silicon oxide and activated carbon; the volume ratio of the carrier to deionized water is 0.1:1 to 10:1, preferably 1:1 to 10:1.

[0039] As a preferred embodiment of the present invention, the noble metal is one or more of platinum, rhodium, ruthenium and palladium; the noble metal precursor solution is one or more of platinum chloride, rhodium chloride, ruthenium chloride and palladium chloride.

[0040] As a preferred embodiment of the present invention, in step 1, the temperature during the precipitation process is controlled at -20 to 80°C, preferably 10 to 80°C; the pH of the system during the precipitation process is controlled at 6 to 10, preferably 7 to 10.

[0041] As a preferred embodiment of the present invention, in step 2, the aging time of the catalyst precursor suspension is 0 to 50 hours, preferably 1 to 30 hours; the temperature during the aging process is controlled at -20 to 80°C, and the pH is controlled at 6 to 10.

[0042] As a preferred embodiment of the present invention, in step 2, the standard for washing completion is that the pH value of the last washing solution is between 7 and 8, preferably between 7 and 7.5; drying can be carried out under vacuum conditions, air atmosphere and inert atmosphere, preferably air atmosphere and inert atmosphere, and the drying temperature is 20 to 200°C, preferably 50 to 150°C; the drying time is 1 to 100 hours, preferably 10 to 80 hours; calcination can be carried out under vacuum conditions, air atmosphere and inert atmosphere, preferably air atmosphere and inert atmosphere; the calcination temperature is 200 to 800°C, preferably 300 to 600°C; the calcination time is 1 to 100 hours, preferably 3 to 50 hours.

[0043] As a preferred embodiment of the present invention, in step 3, the temperature of stirring and evaporating to dryness is controlled to be 40-90°C, preferably 50-80°C.

[0044] Another embodiment of the present invention provides an application of a nickel-based catalyst for hydrogen storage in an organic liquid. The nickel-based catalyst prepared by the above method is applied to a hydrogenation reaction of a catalytic hydrogen storage organic liquid.

[0045] As a preferred embodiment of the present invention, the hydrogen storage organic liquid is one or more of benzyltoluene, dibenzyltoluene, toluene, benzene, quinoline, carbazole and N-ethylcarbazole, but is not limited thereto.

[0046] As a preferred embodiment of the present invention, the temperature of the hydrogenation reaction is 100-500° C., preferably 100-300° C.; the pressure of the hydrogenation reaction is 1-10 MPa, preferably 1-5 MPa.

[0047] It should be noted that the above-mentioned non-precious metal catalyst needs to be placed in a reducing atmosphere for reduction reaction before use, that is, before the catalytic hydrogenation reaction; wherein the reducing atmosphere can be hydrogen or diluted hydrogen; the temperature of the reduction reaction is 200-800°C, preferably 300-600°C; the time of the reduction reaction is 1-100h, preferably 1-50h.

[0048] The following embodiments are some specific implementation cases and application cases of the present invention in practical applications, but are not limited thereto.

[0049] Example 1: A method for preparing a nickel-based catalyst for hydrogenation, comprising the following steps:

[0050] S1. Weigh 13.5g of nickel nitrate hexahydrate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare an active metal salt solution with a concentration of 1mol / L; weigh 13.35g of sodium carbonate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare a precipitate with a concentration of 1mol / L; add 6g of aluminum oxide to deionized water at a volume ratio of 5:1, and continue stirring for 4h at room temperature to obtain a carrier suspension; add the above active metal salt solution and precipitate to the above carrier suspension at the same time to precipitate, and obtain a catalyst precursor suspension; wherein, the temperature during the precipitation process is controlled at 30°C; the system pH is controlled at 8 during the precipitation process. After the above catalyst precursor suspension is aged for 25h, it is filtered to obtain a catalyst precursor; wherein, the temperature during the aging process is controlled at 30°C and the pH is controlled at 8.

[0051] S2. Wash the catalyst precursor with deionized water for multiple times until the pH value of the last washing liquid is between 7 and 8, dry it in an air atmosphere at 80°C for 2 hours, grind it thoroughly, and transfer it to an inert atmosphere at 450°C for calcination for 6 hours to obtain a non-precious metal catalyst (Ni / Al2O3).

[0052] S3. Grind the obtained catalyst into powder, mix it thoroughly in deionized water, and drop 5 mL of 0.00375 g of Pt / mL of platinum chloride solution, which was then stirred and evaporated to dryness to obtain a nickel-based catalyst supported by precious metal Pt.

[0053] Example 2: This example provides a method for preparing a nickel-based catalyst for hydrogenation, which comprises the following steps:

[0054] S1. Weigh 8.89g of nickel nitrate hexahydrate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare an active metal salt solution with a concentration of 1mol / L; weigh 13.35g of ammonium carbonate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare a precipitate with a concentration of 1mol / L; add 6g of magnesium oxide to deionized water at a volume ratio of 5:1, and continue stirring at room temperature for 4h to obtain a carrier suspension; add the above active metal salt solution and precipitate to the above carrier suspension at the same time to precipitate, and obtain a catalyst precursor suspension; wherein, the temperature during the precipitation process is controlled at 30°C; the system pH is controlled at 8 during the precipitation process. After the above catalyst precursor suspension is aged for 25h, it is filtered to obtain a catalyst precursor; wherein, the temperature during the aging process is controlled at 30°C and the pH is controlled at 8. The catalyst precursor was washed with deionized water for several times until the pH value of the last washing liquid was between 7 and 8, and then dried in an air atmosphere at 80°C for 2 hours, and then ground thoroughly and transferred to an inert atmosphere at 450°C for calcination for 6 hours to obtain a non-precious metal catalyst (Ni / MgO).

[0055] S2. Grind the obtained catalyst into powder, fully mix it in deionized water, drop 20 μM of noble metal precursor solution into it, then stir and evaporate to dryness to obtain a noble metal-supported nickel-based catalyst.

[0056] S3. Grind the obtained catalyst into powder, mix it thoroughly in deionized water, and drop 6 mL of 0.0035 g Rh / mL of rhodium chloride solution, followed by stirring and evaporating to dryness to obtain a nickel-based catalyst supported by precious metal Rh.

[0057] Example 3: This example provides a method for preparing a nickel-based catalyst for hydrogenation, which comprises the following steps:

[0058] S1. Weigh 10.7g of nickel nitrate hexahydrate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare an active metal salt solution with a concentration of 1mol / L; weigh 13.35g of ammonium carbonate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare a precipitate with a concentration of 1mol / L; add 10g of aluminum oxide to deionized water at a volume ratio of 5:1, and continue stirring at room temperature for 4h to obtain a carrier suspension; add the above active metal salt solution and precipitate to the above carrier suspension at the same time to precipitate, and obtain a catalyst precursor suspension; wherein, the temperature during the precipitation process is controlled at 30°C; and the system pH is controlled at 8 during the precipitation process. After the above catalyst precursor suspension is aged for 25h, it is filtered to obtain a catalyst precursor; wherein, the temperature during the aging process is controlled at 30°C and the pH is controlled at 8.

[0059] S2. Wash the catalyst precursor with deionized water for multiple times until the pH value of the last washing liquid is between 7 and 8, dry it in an air atmosphere at 80°C for 2 hours, grind it thoroughly, and transfer it to an inert atmosphere at 450°C for calcination for 6 hours to obtain a non-precious metal catalyst (Ni / Al2O3).

[0060] S3. Grind the obtained catalyst into powder, mix it thoroughly in deionized water, and drop 3 mL of 0.00375 g Ru / mL of ruthenium chloride solution, which was then stirred and evaporated to dryness to obtain a nickel-based catalyst supported by precious metal Ru.

[0061] Example 4: This example provides a method for preparing a nickel-based catalyst for hydrogenation, which comprises the following steps:

[0062] S1. Weigh 14g of nickel nitrate hexahydrate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare an active metal salt solution with a concentration of 1.5mol / L; weigh 12.54g of sodium carbonate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare a precipitate with a concentration of 0.9mol / L; add 7g of magnesium oxide to deionized water at a volume ratio of 5:1, and continue stirring at room temperature for 4h to obtain a carrier suspension; add the above active metal salt solution and precipitate to the above carrier suspension at the same time to precipitate, and obtain a catalyst precursor suspension; wherein, the temperature during the precipitation process is controlled at 30°C; and the system pH is controlled at 8 during the precipitation process. After the above catalyst precursor suspension is aged for 25h, it is filtered to obtain a catalyst precursor; wherein, the temperature during the aging process is controlled at 30°C and the pH is controlled at 8.

[0063] S2. Wash the catalyst precursor with deionized water for multiple times until the pH value of the last washing liquid is between 7 and 8, dry it in an air atmosphere at 80°C for 2 hours, grind it thoroughly, and transfer it to an inert atmosphere at 450°C for calcination for 6 hours to obtain a non-precious metal catalyst (Ni / MgO).

[0064] S3, grind the obtained catalyst into powder, mix it thoroughly in deionized water, and drop 6 mL of 0.00325 g Pd / mL of palladium chloride solution, followed by stirring and evaporating to dryness to obtain a nickel-based catalyst supported by precious metal Pd.

[0065] Comparative Example 1: This example provides a method for preparing a nickel-based catalyst for hydrogenation, which comprises the following steps:

[0066] S1. Weigh 13.5g of nickel nitrate hexahydrate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare an active metal salt solution with a concentration of 1mol / L; weigh 13.35g of sodium carbonate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare a precipitate with a concentration of 1mol / L; add 6g of aluminum oxide to deionized water at a volume ratio of 5:1, and continue stirring for 4h at room temperature to obtain a carrier suspension; add the above active metal salt solution and precipitate to the above carrier suspension at the same time to precipitate, and obtain a catalyst precursor suspension; wherein, the temperature during the precipitation process is controlled at 30°C; the system pH is controlled at 8 during the precipitation process. After the above catalyst precursor suspension is aged for 25h, it is filtered to obtain a catalyst precursor; wherein, the temperature during the aging process is controlled at 30°C and the pH is controlled at 8.

[0067] S2. Wash the catalyst precursor with deionized water for several times until the pH value of the last washing liquid is between 7 and 8, dry it in an air atmosphere at 80°C for 2 hours, grind it thoroughly, and transfer it to an inert atmosphere at 450°C for calcination for 6 hours to obtain a metal catalyst (Ni / Al2O3).

[0068] Comparative Example 2: This example provides a method for preparing a nickel-based catalyst for hydrogenation, which comprises the following steps:

[0069] S1. Weigh 8.89g of nickel nitrate hexahydrate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare an active metal salt solution with a concentration of 1mol / L; weigh 13.35g of ammonium carbonate and add it to an appropriate amount of deionized water, stir it evenly at room temperature, and prepare a precipitate with a concentration of 1mol / L; add 6g of magnesium oxide to deionized water at a volume ratio of 5:1, and continue stirring at room temperature for 4h to obtain a carrier suspension; add the above active metal salt solution and precipitate to the above carrier suspension at the same time to precipitate, and obtain a catalyst precursor suspension; wherein, the temperature during the precipitation process is controlled at 30°C; the system pH is controlled at 8 during the precipitation process. After the above catalyst precursor suspension is aged for 25h, it is filtered to obtain a catalyst precursor; wherein, the temperature during the aging process is controlled at 30°C and the pH is controlled at 8. The catalyst precursor was washed with deionized water for several times until the pH value of the last washing liquid was between 7 and 8, and then dried in an air atmosphere at 80°C for 2 hours, and then fully ground and transferred to an inert atmosphere at 450°C for calcination for 6 hours to obtain a metal catalyst (Ni / MgO).

[0070] Application example: The metal catalysts prepared in the above-mentioned embodiments 1 to 4 and comparative examples 1 and 2 are applied to the hydrogenation reaction of hydrogen storage organic liquids such as benzyltoluene and dibenzyltoluene, and the measured hydrogenation degrees of benzyltoluene and dibenzyltoluene are shown in Table 1. The test method is as follows: weigh an appropriate amount of the above-mentioned 40-60 mesh metal catalyst and dilute it with quartz sand at a mass ratio of 1:1, and then evaluate it in a trickle bed device; the metal catalyst is first subjected to a reduction reaction before use, and specifically, the reduction heating program is: 30 minutes from room temperature to 120°C, and then maintained for 60 minutes; then heated to 400°C at a heating rate of 1°C / min for reduction reaction, and maintained for 5 hours; after the reduction is completed, the temperature is lowered to 200°C for 5 minutes, the gas is switched to pure hydrogen, and the back pressure is initially 4MPa. Then the metering pump is turned on to start sampling, the tail gas is analyzed by chromatography, and the hydrogen liquid is qualitatively and quantitatively analyzed by GC-MS.

[0071] Table 1

[0072] Example Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 catalyst <![CDATA[PtNi / Al2O3]]> RhNi / MgO <![CDATA[RuNi / Al2O3]]> PdNi / MgO <![CDATA[Ni / Al2O3]]> Ni / MgO Benzyltoluene hydrogenation degree 100 99 99 98 85 83 Dibenzyltoluene hydrogenation degree 100 98 97 95 78 75

[0073] From the above results, it can be seen that the nickel catalyst prepared by this method has a high hydrogenation activity when applied to the hydrogenation reaction liquid of organic matter. In the hydrogenation reaction of organic hydrogen storage materials, the catalyst prepared by this method has a hydrogenation degree of 100% for benzyltoluene and a hydrogenation degree of 100% for dibenzyltoluene.

Claims

1. A method for preparing a nickel-based catalyst for hydrogen storage in organic liquid, characterized in that: The following steps are involved: Step 1: simultaneously adding a nickel metal salt solution and a precipitate solution to a carrier suspension to perform precipitation, thereby obtaining a catalyst precursor suspension; wherein the precipitate solution is an alkaline solution; Step 2: aging and filtering the catalyst precursor suspension to obtain a catalyst precursor, and washing, drying and calcining the catalyst precursor to obtain a nickel-based catalyst; Step 3: Grind the obtained nickel-based catalyst into powder, mix it thoroughly in deionized water, drop a small amount of precious metal precursor solution into it, and then stir and evaporate to dryness.

2. The method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid according to claim 1, characterized in that: The nickel metal salt solution is prepared by mixing nickel salt and deionized water; the precipitate is prepared by mixing alkali and deionized water; the molar concentration of the active metal salt in the metal salt solution is 0.01-5 mol / L; the molar concentration of the alkali in the precipitate is 0.01-5 mol / L.

3. The method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid according to claim 2, characterized in that: The nickel metal salt is one or more of nickel nitrate, acetate, halide and sulfate; The alkali is one or more of sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydroxide, potassium hydroxide, ammonia water, sodium bicarbonate, potassium bicarbonate and ammonium bicarbonate.

4. The method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid according to claim 2, characterized in that: The carrier suspension is a mixture of a carrier and deionized water, and a uniformly mixed carrier suspension is formed by dispersing the carrier in deionized water and continuously stirring; the carrier is one or more of aluminum oxide, magnesium oxide, manganese oxide, silicon oxide and activated carbon; the volume ratio of the carrier to deionized water is 0.1:1 to 10:

1.

5. The method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid according to claim 1, characterized in that: The noble metal is one or more of platinum, rhodium, ruthenium and palladium; the noble metal precursor solution is one or more of platinum chloride, rhodium chloride, ruthenium chloride and palladium chloride.

6. The method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid according to claim 1, characterized in that: In step 1, the temperature during the precipitation process is controlled at -20 to 80°C; the pH of the system is controlled at 6 to 10 during the precipitation process; In step 2, the aging time of the catalyst precursor suspension is 0 to 50 hours, the temperature during the aging process is controlled at -20 to 80°C, and the pH is controlled at 6 to 10; the standard for completion of washing is that the pH value of the last washing liquid is between 7 and 8; drying is carried out under vacuum conditions, air atmosphere or inert atmosphere, the drying temperature is 20 to 200°C, and the drying time is 1 to 100 hours; calcination is carried out under vacuum conditions, air atmosphere or inert atmosphere, the calcination temperature is 200 to 800°C, and the calcination time is 1 to 100 hours; In step 3, the temperature of stirring and evaporating to dryness is controlled at 40-90°C.

7. An application of a nickel-based catalyst for hydrogen storage in an organic liquid, the nickel-based catalyst prepared by the method for preparing a nickel-based catalyst for hydrogen storage in an organic liquid according to any one of claims 1 to 6, characterized in that: The nickel-based catalyst is applied to catalyze hydrogen storage organic liquid for hydrogenation reaction.

8. The use of the nickel-based catalyst for hydrogen storage in organic liquid according to claim 7, characterized in that: The hydrogen storage organic liquid is one or more of benzyltoluene, dibenzyltoluene, toluene, benzene, quinoline, carbazole and N-ethylcarbazole.

9. The use of the nickel-based catalyst for hydrogen storage in organic liquid according to claim 7, characterized in that: The temperature of the hydrogenation reaction is 100-500° C., and the pressure of the hydrogenation reaction is 1-10 MPa.

10. The use of the nickel-based catalyst for hydrogen storage in organic liquid according to claim 7, characterized in that: Before use, that is, before catalytic hydrogenation, the nickel-based catalyst needs to be placed in a reducing atmosphere for reduction reaction; wherein the reducing atmosphere is hydrogen or diluted hydrogen; the temperature of the reduction reaction is 200-800° C., and the time of the reduction reaction is 1-100 hours.