Preparation method and application of bimetallic catalyst for organic liquid hydrogen storage process

Abstract

The present invention discloses a method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process. The method comprises the following steps: mixing a nickel salt, a cobalt salt, ethylenediaminetetramethylenephosphonic acid, alanine, and a certain amount of deionized water to obtain a uniform composite active metal precursor impregnation solution; mixing the solution with pseudo-boehmite powder, ethylene glycol, hydrazine hydrate, and a dispersant and ultrasonically dispersing the solution to obtain a suspended fluid; then reducing the active metal component, adding a binder to the obtained semi-dry and semi-wet material, kneading the mixture, and extruding it into strips. Finally, drying the mixture to remove moisture and impurities, thereby obtaining a supported non-precious bimetallic cobalt-nickel hydrogenation catalyst for use in an organic liquid hydrogen storage process. The present invention obtains a supported non-precious bimetallic cobalt-nickel catalyst by adopting a suitable preparation method, which not only improves the activity of non-precious monometallic catalysts in the organic liquid hydrogenation process, but also avoids the high cost problem faced by using precious metal catalysts.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy storage and transportation, and in particular to a preparation method and application of a bimetallic catalyst for an organic liquid hydrogen storage process. Background Art

[0002] As a green and sustainable new energy source with abundant resources, wide sources, high energy density and clean combustion, the application of hydrogen energy can solve the current difficulties faced by fossil energy. The hydrogen energy industry chain includes hydrogen preparation, storage, transportation and application, among which hydrogen energy storage is the technical bottleneck problem in the current development of hydrogen energy. Hydrogen storage technologies are mainly divided into two categories: physical hydrogen storage and chemical hydrogen storage. Organic liquid hydrogen storage technology based on chemical reaction method has attracted great attention due to its advantages such as large hydrogen storage capacity, high energy density, safe and convenient liquid storage and transportation. Organic liquid hydrogen storage technology uses the reversible catalytic addition and dehydrogenation reaction of unsaturated aromatic hydrocarbons and corresponding hydrides (saturated aromatic hydrocarbons) to achieve hydrogen energy storage and release. Since the reaction process is highly reversible, the reactants and products can be recycled. At the same time, since the properties of organic liquids are similar to those of oil products, they can make full use of existing oil storage and transportation infrastructure for storage and transportation, which can significantly reduce the cost of hydrogen storage and transportation. Moreover, long-distance transportation in the form of organic liquids can also solve the problem of uneven regional distribution of energy. Therefore, this technology is considered to be an effective means to solve large-scale hydrogen storage, long-distance hydrogen transportation and replace traditional fossil fuels, and will play a vital role in the future "hydrogen economy era".

[0003] In recent years, research on hydrogenation catalysts used in the process of hydrogen storage in organic liquids has mainly focused on precious metal catalysts. Although precious metals have good catalytic activity, the large-scale use of precious metals also brings about the problem of high costs, which has caused certain difficulties for the large-scale promotion of organic liquid hydrogen storage technology. The existing conventional supported non-precious single metal catalysts not only have low activity, making it difficult to achieve complete hydrogenation of organic liquids, but their production process also needs further improvement to reduce costs and increase efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method and application of a bimetallic catalyst for an organic liquid hydrogen storage process to solve the problems raised in the background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process comprises the following steps: step S1: mixing and stirring a nickel salt, a cobalt salt, ethylenediaminetetramethylenephosphonic acid, alanine and a certain amount of deionized water to obtain a uniform composite active metal precursor impregnation solution; step S2: mixing the composite active metal precursor impregnation solution with pseudo-boehmite powder, ethylene glycol, hydrazine hydrate and a dispersant, and performing ultrasonic dispersion to obtain a suspended fluid; step S3: placing the suspended fluid in an industrial microwave oven, reducing the active metal components by microwave heating, adding a binder to the obtained semi-dry and semi-wet material, kneading it, and extruding it into strips, and finally drying it in the industrial microwave oven to remove moisture and other volatile impurities, thereby obtaining a supported non-precious bimetallic cobalt-nickel hydrogenation catalyst for an organic liquid hydrogen storage process.

[0007] On the basis of the above technical solutions, the present invention also provides the following optional technical solutions:

[0008] In an optional embodiment, the nickel salt and the cobalt salt are both selected from one or more of basic carbonates, nitrates and acetates; wherein the molar ratio of the nickel salt to the cobalt salt is 0.3:1-1:0.3.

[0009] In an optional solution, the molar amount of EDTA is 5% to 20% of the total molar amount of the nickel salt and the cobalt salt, and the molar amount of alanine is 5% to 20% of the total molar amount of the nickel salt and the cobalt salt.

[0010] In an optional solution, the molar weight of the pseudo-boehmite powder is 20% to 80% of the total molar weight of the nickel salt and the cobalt salt.

[0011] In an optional solution, the amount of ethylene glycol used is 50% to 80% of the total molar amount of the nickel salt and the cobalt salt; the amount of hydrazine hydrate used is 50% to 100% of the total molar amount of the nickel salt and the cobalt salt.

[0012] In an optional embodiment, the dispersant is one or more of trioctyl phosphate, methylpentanol, cellulose derivatives, polyacrylamide, guar gum, polyethylene wax, oxidized polyethylene wax, polyethylene glycol, polyvinyl alcohol, polypropylene alcohol, methyl cellulose, carboxymethyl cellulose, isopropyl alcohol, sec-butyl alcohol, levulinic acid ester, paraffin, polyurethane, fatty acid glyceride, fatty acid sorbitan, Tween and acrylic polymers, and the amount of the dispersant is 1wt% to 20wt% of the weight of the pseudo-boehmite powder.

[0013] In an optional solution: in step S2, the ultrasonic dispersion time is 30 to 60 minutes.

[0014] In an optional solution, the binder is one or more of aluminum sol, silica sol and silica-alumina gel, and the amount of the binder is 1 wt% to 5 wt% of the weight of the pseudo-boehmite powder.

[0015] In an optional solution, the microwave heating reduction temperature is 100° C. to 250° C., the heating reduction time is 5 to 30 minutes, and the microwave drying time is 45 to 120 minutes.

[0016] The supported cobalt-nickel hydrogenation catalyst prepared according to the above-mentioned preparation method of the bimetallic catalyst for the organic liquid hydrogen storage process is used in the organic liquid hydrogen storage process.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The supported cobalt-nickel hydrogenation catalyst prepared by the method of the present invention is mainly used in the organic liquid hydrogen storage process and is suitable for treating one or more unsaturated aromatic hydrocarbons such as, but not limited to, naphthalene, biphenyl, terphenyl, benzyltoluene, dibenzyltoluene, etc.

[0019] The preparation method of the supported non-precious bimetallic cobalt-nickel catalyst described in the present invention is to introduce two chelating agents, combine impregnation, ultrasonic dispersion, microwave heating reduction, kneading and molding, and microwave drying treatment to promote the uniform dispersion of the two active metals while improving the synergy between different active metals. The active metals are directly kneaded and molded with pseudo-boehmite powder, and microwave low-temperature reduction and drying are performed to prevent sintering of metal particles, thereby preparing a high-performance hydrogenation catalyst for the organic liquid hydrogen storage process, thereby achieving cost reduction and efficiency improvement. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the embodiments listed in the present invention are only used to illustrate the present invention and are not used to limit the scope of the present invention. Any obvious modifications or changes made to the present invention do not depart from the spirit and scope of the present invention.

[0021] The present invention provides a method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process. The method comprises the following steps: first, mixing a nickel salt, a cobalt salt, ethylenediaminetetramethylenephosphonic acid (EDTPMP), alanine, and a certain amount of deionized water to obtain a uniform composite active metal precursor impregnation solution; then, mixing the impregnation solution with pseudo-boehmite powder, ethylene glycol, hydrazine hydrate, and a dispersant, and ultrasonically dispersing the mixture to obtain a suspension; then, placing the impregnation solution in an industrial microwave oven and heating it to 100°C-250°C to reduce the active metal components; then, adding a binder to the obtained semi-dry and semi-wet material, kneading the mixture, and extruding it into strips; and finally, drying the mixture in an industrial microwave oven to remove moisture and other volatile impurities, thereby obtaining an organic liquid hydrogenation catalyst. The nickel salt and cobalt salt are selected from one or more of basic carbonates, nitrates, and acetates. The molar ratio of the nickel salt to the cobalt salt is 0.3:1-1:0.3, preferably 0.5:1-1:0.5.

[0022] The molar amounts of ethylenediaminetetramethylenephosphonic acid (also known as ethylenediaminetetramethylenephosphonic acid) and alanine used are 5% to 20% of the total molar amount of nickel salt and cobalt salt respectively.

[0023] The pseudo-boehmite powder is an industrial product, for example, but not limited to the pseudo-boehmite powder produced by Zibo Baida Chemical Co., Ltd. The molar amount of the pseudo-boehmite powder used is 20% to 80% of the total molar amount of the nickel salt and the cobalt salt.

[0024] The amount of ethylene glycol used is 50% to 80% of the total molar amount of the nickel salt and the cobalt salt;

[0025] The amount of hydrazine hydrate used is 50% to 100% of the total molar amount of nickel salt and cobalt salt;

[0026] The dispersant is one or more of trioctyl phosphate, methyl amyl alcohol, polyacrylamide, gum guar, polyethylene wax, oxidized polyethylene wax, polyethylene glycol, polyvinyl alcohol, polypropylene alcohol, methyl cellulose, carboxymethyl cellulose, isopropyl alcohol, sec-butyl alcohol, levulinic acid ester, paraffin, polyurethane, fatty acid glyceride, fatty acid sorbitan and Tween, and the amount used is 1wt%-20wt% of the weight of the pseudo-boehmite powder.

[0027] The binder is one or more of aluminum sol, silica sol and silica-alumina gel, and the amount used is 1wt%-5wt% of the weight of the pseudo-boehmite powder.

[0028] The ultrasonic time is 30 to 60 minutes, and the ultrasonic instrument is selected from, for example, but not limited to, a 35kHz ultrasonic cleaner produced by Titan Technology Co., Ltd.

[0029] The microwave heating reduction temperature is 100-250°C, the heating reduction time is 5-30 minutes, and the microwave drying time is 45-120 minutes. The microwave oven is selected from, for example, but not limited to, the industrial microwave oven manufactured by Shanghai Bio Microwave Energy Equipment Co., Ltd.

[0030] The following are the detailed steps of each embodiment:

[0031] Example 1

[0032] 291 g of nickel nitrate hexahydrate, 249 g of cobalt acetate tetrahydrate, 50 g of ethylenediaminetetramethylenephosphonic acid, 35 g of alanine and 500 g of deionized water were mixed, heated and stirred to obtain a composite active metal precursor impregnation solution, which was then mixed with 50 g of pseudo-boehmite powder, 88 g of ethylene glycol, 65 g of hydrazine hydrate and 5 g of paraffin wax, ultrasonically dispersed for 40 minutes, and then subjected to microwave heating reduction at 180° C. for 10 minutes. Subsequently, 2 g of aluminum sol was added to the obtained material, mixed and kneaded, and extruded into strips, which were then microwave dried for 60 minutes to finally obtain an organic liquid hydrogenation catalyst 1, wherein the molar ratio of metallic nickel to cobalt was 0.3:1.

[0033] Example 2

[0034] 136 g of basic nickel carbonate, 88 g of cobalt nitrate hexahydrate, 32 g of ethylenediaminetetramethylenephosphonic acid, 20 g of alanine and 200 g of deionized water were mixed, heated and stirred to obtain a composite active metal precursor impregnation solution, which was then mixed with 40 g of pseudo-boehmite powder, 50 g of ethylene glycol, 36 g of hydrazine hydrate and 4 g of methylpentanol, ultrasonically dispersed for 60 minutes, and then subjected to microwave heating reduction at 100° C. for 30 minutes. Subsequently, 2 g of silica sol was added to the obtained material, mixed and kneaded, and extruded into strips, which were then microwave dried for 45 minutes to obtain an organic liquid hydrogenation catalyst 2, wherein the molar ratio of metallic nickel to cobalt was 1:0.3.

[0035] Example 3

[0036] 125 g of nickel acetate tetrahydrate, 136 g of basic cobalt carbonate, 75 g of ethylenediaminetetramethylenephosphonic acid, 20 g of alanine and 250 g of deionized water were mixed, heated and stirred to obtain a composite active metal precursor impregnation solution, which was then mixed with 70 g of pseudo-boehmite powder, 65 g of ethylene glycol, 70 g of hydrazine hydrate and 1 gram of polyacrylamide, and ultrasonically dispersed for 30 minutes. The mixture was then subjected to microwave heating reduction at 250°C for 5 minutes. 2 g of silica-alumina gel was then added to the obtained material, mixed and kneaded, and extruded into strips. The mixture was then microwave-dried for 120 minutes to obtain an organic liquid hydrogenation catalyst 3, in which the molar ratio of metallic nickel to cobalt was 0.5:1.

[0037] Example 4

[0038] 249 g of nickel acetate tetrahydrate, 125 g of cobalt acetate tetrahydrate, 60 g of ethylenediaminetetramethylenephosphonic acid, 10 g of alanine and 400 g of deionized water were mixed, heated and stirred to obtain a composite active metal precursor impregnation solution, which was then mixed with 80 g of pseudo-boehmite powder, 60 g of ethylene glycol, 50 g of hydrazine hydrate and 10 g of polyethylene glycolamine, ultrasonically dispersed for 45 minutes, and then subjected to microwave heating reduction at 200°C for 15 minutes. Subsequently, 3 g of aluminum sol was added to the obtained material, mixed and kneaded, and extruded into strips, which were then microwave dried for 100 minutes to obtain an organic liquid hydrogenation catalyst 4, wherein the molar ratio of metallic nickel to cobalt was 1:0.5.

[0039] Comparative Example 1 (Compared with Example 1, the total amount of metal loading is the same):

[0040] 582 grams of nickel nitrate hexahydrate, 50 grams of ethylenediaminetetramethylenephosphonic acid, 35 grams of alanine and 500 grams of deionized water were mixed, heated and stirred to obtain a composite active metal precursor impregnation solution, which was mixed with 50 grams of pseudo-boehmite powder, 88 grams of ethylene glycol, 65 grams of hydrazine hydrate and 5 grams of paraffin, ultrasonically dispersed for 40 minutes, and then microwave-heated for reduction at a temperature of 180°C for 10 minutes. Subsequently, 2 grams of aluminum sol were added to the obtained material, mixed and kneaded, and extruded into strips, and then microwave-dried for 60 minutes to obtain a non-precious single metal catalyst A, which is a supported nickel catalyst.

[0041] Comparative Example 2 (Compared with Example 3, the total amount of metal loading is the same):

[0042] 204 g of basic cobalt carbonate, 75 g of ethylenediaminetetramethylenephosphonic acid, 20 g of alanine and 250 g of deionized water were mixed, heated and stirred to obtain a composite active metal precursor impregnation solution, which was then mixed with 70 g of pseudo-boehmite powder, 65 g of ethylene glycol, 70 g of hydrazine hydrate and 1 gram of polyacrylamide, ultrasonically dispersed for 30 minutes, and then subjected to microwave heating reduction at a temperature of 250°C for 5 minutes. Subsequently, 2 g of silica-alumina gel was added to the obtained material, mixed and kneaded, and extruded into strips, which were then microwave-dried for 120 minutes to obtain a non-precious single metal catalyst B, which is a supported cobalt catalyst.

[0043] The aforementioned organic liquid hydrogenation catalysts 1, 2, and 3, as well as non-precious metal catalysts A and B, were evaluated for activity in a 100 mL small-scale high-pressure hydrogenation apparatus, using naphthalene and dibenzyltoluene as the hydrogenation feedstocks, respectively. The evaluation conditions were: a hydrogen partial pressure of 5 MPa, a reaction temperature of 200°C, a catalyst-to-feedstock mass ratio of 0.10, and a reaction time of 3 hours. The catalyst evaluation results are shown in Table 1 below. The hydrogenation saturation of the organic liquid refers to the percentage of the actual hydrogenation amount to the theoretically complete hydrogenation amount.

[0044] Table 1 Catalyst hydrogenation saturation for naphthalene and dibenzyltoluene

[0045]

[0046] From the above results, it can be seen that the organic liquid hydrogen storage bulk catalyst obtained by the method of the present invention has better hydrogenation activity.

[0047] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process, characterized in that: The method comprises the following steps: step S1: mixing and stirring nickel salt, cobalt salt, ethylenediaminetetramethylenephosphonic acid, alanine and a certain amount of deionized water to obtain a uniform composite active metal precursor impregnation liquid; step S2: mixing the composite active metal precursor impregnation liquid with pseudo-boehmite powder, ethylene glycol, hydrazine hydrate and a dispersant, and performing ultrasonic dispersion to obtain a suspended fluid; step S3: placing the suspended fluid in an industrial microwave oven, reducing the active metal components by microwave heating, adding a binder to the obtained semi-dry and semi-wet material, kneading it, and extruding it into strips, and finally drying it in the industrial microwave oven to remove moisture and other volatile impurities, thereby obtaining a supported non-precious bimetallic cobalt-nickel hydrogenation catalyst for an organic liquid hydrogen storage process.

2. The method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process according to claim 1, wherein: The nickel salt and the cobalt salt are both selected from one or more of basic carbonates, nitrates and acetates; wherein the molar ratio of the nickel salt to the cobalt salt is 0.3:1-1:0.

3.

3. The method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process according to claim 1, wherein: The molar amount of the ethylenediaminetetramethylenephosphonic acid is 5% to 20% of the total molar amount of the nickel salt and the cobalt salt, and the molar amount of alanine is 5% to 20% of the total molar amount of the nickel salt and the cobalt salt.

4. The method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process according to claim 1, wherein: The molar weight of the pseudo-boehmite powder is 20% to 80% of the total molar weight of the nickel salt and the cobalt salt.

5. The method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process according to claim 1, wherein: The amount of ethylene glycol used is 50% to 80% of the total molar amount of the nickel salt and the cobalt salt; the amount of hydrazine hydrate used is 50% to 100% of the total molar amount of the nickel salt and the cobalt salt.

6. The method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process according to claim 1, wherein: The dispersant is one or more of trioctyl phosphate, methylpentyl alcohol, polyacrylamide, gum guar, polyethylene wax, oxidized polyethylene wax, polyethylene glycol, polyvinyl alcohol, polypropylene alcohol, methyl cellulose, carboxymethyl cellulose, isopropyl alcohol, sec-butyl alcohol, levulinic acid ester, paraffin, polyurethane, fatty acid glyceride, fatty acid sorbitan and Tween, and the amount of the dispersant is 1wt% to 20wt% of the weight of the pseudo-boehmite powder.

7. The method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process according to claim 1, wherein: In step S2, the ultrasonic dispersion time is 30 to 60 minutes.

8. The method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process according to claim 1, wherein: The binder is one or more of aluminum sol, silica sol and silica-alumina gel, and the amount of the binder is 1wt% to 5wt% of the weight of the pseudo-boehmite powder.

9. The method for preparing a bimetallic catalyst for an organic liquid hydrogen storage process according to claim 1, wherein: In step S3, the microwave heating reduction temperature is 100° C. to 250° C., the heating reduction time is 5 to 30 minutes, and the microwave drying time is 45 to 120 minutes.

10. Use of the supported cobalt-nickel hydrogenation catalyst prepared by the method for preparing a bimetallic catalyst for organic liquid hydrogen storage according to any one of claims 1 to 9 in an organic liquid hydrogen storage process.

Images