A high specific surface area nickel-coated aluminum powder, preparation method and hydrogen production method

Abstract

The present application discloses a high specific surface area nickel-coated aluminum powder, a preparation method and a hydrogen production method, and relates to the field of metal powder technology. Aluminum powder is etched to form porous aluminum powder; a conductive nanomaterial is loaded onto the surface and pore structure of the porous aluminum powder to obtain a modified porous aluminum powder; the modified porous aluminum powder, a nickel source, a cobalt source and other reagents are mixed evenly in a solvent, the pH is adjusted, and then heated and stirred to form a nickel-cobalt-modified porous aluminum powder gel. After further drying and calcination, the high-valent nickel and high-valent cobalt in the nickel-cobalt-modified porous aluminum powder gel are reduced to metallic nickel and metallic cobalt, which are coated on the modified porous aluminum powder to obtain a high specific surface area nickel-coated aluminum powder. The nickel-coated aluminum powder prepared by this technical solution has a porous structure, a high specific surface area, and a uniform coating of the cobalt-containing nickel layer; and the preparation method is simple, and the electrical properties are excellent while the catalytic performance is also excellent. It can be used as a reaction catalyst in the hydrogen production industry.

Description

Technical Field

[0001] The present application relates to the technical field of metal powders, and in particular to a high specific surface area nickel-coated aluminum powder, a preparation method, and a hydrogen production method. Background Art

[0002] With the continued rise in global energy demand and increasingly severe environmental issues, the demand for high-performance materials in electronics, aerospace, chemical catalysis, and other fields is also growing. Nickel-based materials, with their unique electrical and thermal properties and excellent catalytic performance, are expected to play an important role in these fields, such as in the preparation of highly conductive heat dissipation materials and electromagnetic shielding materials. However, pure nickel-based materials often have various shortcomings, making them difficult to meet practical needs.

[0003] Composite materials are a key strategy for improving performance. Aluminum, with its high conductivity, high reducibility, abundant reserves, and unique physicochemical properties, combines with nickel to create innovative new functional material systems. By coating aluminum powder with nickel to form nickel-coated aluminum powder, the catalytic advantages of nickel can be combined with the properties of aluminum to further enhance the material's performance.

[0004] However, preparing nickel-coated aluminum powder with a high specific surface area presents numerous challenges. Conventional coating methods often produce nickel-coated aluminum powder with agglomerates, uneven nickel coating, and difficulty in further compounding other functional materials within the nickel layer. This results in the powder being unable to fully realize its application value in other fields such as catalysis and electronics.

[0005] A Chinese patent application with publication number CN 112264613A discloses a method for preparing nickel-coated aluminum powder for electromagnetic shielding, which comprises the following steps: first, degreasing the aluminum powder; then, preparing a dopamine solution, adding the aluminum powder, and stirring to obtain dopamine-coated aluminum powder; placing the aluminum powder in a nickel sulfate hexahydrate solution and continuously stirring to form nickel active sites on the surface of the aluminum powder; washing and filtering to obtain activated aluminum powder; preparing a sodium hypophosphite solution, adding anhydrous ethanol, anhydrous sodium pyrophosphate, and polyvinylpyrrolidone, adding the activated aluminum powder, and finally, dripping the nickel sulfate hexahydrate solution into the solution for a reduction reaction. During the reaction, concentrated ammonia is used to adjust the pH. After titration, the reaction is continued for a period of time, and the powder is washed with water and dried to obtain the nickel-coated aluminum powder.

[0006] Although the above technical solution can produce nickel-coated aluminum powder with better coating, the preparation process is too complicated and the method can still be improved; and the nickel-coated aluminum powder produced by this technical solution does not have a porous structure and has a low specific surface area. Summary of the Invention

[0007] In response to the deficiencies in the prior art, the present application provides a high specific surface area nickel-coated aluminum powder, a preparation method, and a hydrogen production method. The method comprises uniformly mixing conductive nanomaterials, a nickel source, aluminum powder, a solvent, and other reagents in a suitable ratio and addition method, adjusting the pH, and then heating and stirring to form a nickel-cobalt-modified porous aluminum powder gel. The high specific surface area nickel-coated aluminum powder is obtained after further drying and calcination. The nickel-coated aluminum powder has a high specific surface area, a uniformly coated nickel layer containing cobalt, a simple preparation method, excellent electrical properties, and excellent catalytic properties. It can be used as a reaction catalyst in the hydrogen production industry.

[0008] To achieve the above objectives, this application adopts the following technical solutions:

[0009] In the first aspect, the present application provides a nickel-coated aluminum powder with a high specific surface area, wherein the nickel-coated aluminum powder includes a modified porous aluminum powder and a cobalt-containing nickel layer; the cobalt-containing nickel layer is coated on the pore structure and outer surface of the modified porous aluminum powder; the modified porous aluminum powder includes porous aluminum powder and a conductive nanomaterial; the conductive nanomaterial is loaded on the pore structure and outer surface of the porous aluminum powder; the conductive nanomaterial includes any one of graphene oxide and carboxylated carbon nanotubes.

[0010] In a second aspect, the present application provides a method for preparing nickel-coated aluminum powder with a high specific surface area, comprising:

[0011] Under nitrogen protection, aluminum powder is added to a sodium hydroxide solution and etched for a first time to obtain porous aluminum powder;

[0012] Adding the conductive nanomaterial, surfactant and porous aluminum powder into the solvent, and ultrasonically stirring for a second time to obtain a modified porous aluminum powder dispersion;

[0013] adding a nickel source, a cobalt source, and a complexing agent to a modified porous aluminum powder dispersion, adjusting the pH to 7-8, and continuously stirring at the first temperature for a third time to form a nickel-cobalt-modified porous aluminum powder gel;

[0014] The nickel-cobalt-modified porous aluminum powder gel is dried at the second temperature for a fourth time, and then calcined at the third temperature in a nitrogen atmosphere for a fifth time to obtain the high specific surface area nickel-coated aluminum powder.

[0015] In a third aspect, the present application provides a method for producing hydrogen, wherein the method uses nickel-coated aluminum powder with a high specific surface area as a reaction catalyst.

[0016] Beneficial technical effects:

[0017] The present application etches, modifies, coats and calcines aluminum powder to make the prepared nickel-coated aluminum powder have a porous structure, thereby greatly increasing the specific surface area.

[0018] When sodium hydroxide etches aluminum, a chemical reaction generates hydrogen bubbles. Their escape creates micron- to nanometer-sized pores on the aluminum powder's surface. Simultaneously, water participates in the etching process, generating reactive hydroxyl groups within the pores and on the aluminum powder's surface. When the conductive nanomaterial is mixed and dispersed with the porous aluminum powder in a solvent, it adsorbs onto the porous aluminum powder's surface and pore structure. After further addition of a nickel source and a complexing agent, the resulting nickel-cobalt-modified porous aluminum powder gel, heated and stirred, prevents the conductive nanomaterial from detaching from the adsorbed porous aluminum powder's surface and pore structure. After calcination, the organic groups on the conductive nanomaterial react with the hydroxyl groups on the porous aluminum powder at high temperatures, forming a chemical bond and strengthening the bond. Simultaneously, the high-valent nickel and high-valent cobalt in the nickel-cobalt-modified porous aluminum powder gel are reduced to metallic nickel and cobalt by the reducing gases generated by the decomposition of the organic components in the gel, forming a cobalt-nickel layer that coats the modified porous aluminum powder. The resulting nickel-coated aluminum powder is a composite of the cobalt-nickel layer, the conductive nanomaterial, and the porous aluminum powder. The resulting nickel-coated aluminum powder possesses numerous pores and channels, significantly increasing its specific surface area and serving as active sites for catalytic reactions. Furthermore, the nickel layer contains cobalt, which further forms bimetallic active sites with the nickel, enhancing the powder's catalytic performance. Furthermore, both the cobalt-containing nickel layer and the aluminum itself possess excellent electrical conductivity. When combined with conductive nanomaterials with conjugated electron structures, the resulting conductive network is further enhanced, enriching electron transport pathways and significantly improving the powder's electrical conductivity and electromagnetic shielding properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the reaction mechanism for preparing nickel-coated aluminum powder.

[0020] Figure 2 It is a schematic diagram of the process for preparing nickel-coated aluminum powder. DETAILED DESCRIPTION

[0021] In order to make the content of this application easier to understand, the technical solutions described in this application are further described below in conjunction with specific embodiments, but this application is not limited thereto. Any equivalent transformation or simple replacement made based on the substantive content of this application shall fall within the scope of protection of this application.

[0022] As used in this application, the singular forms "for," "or," "an," "any," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0023] This application adopts the following technical solutions:

[0024] In the first aspect, the present application provides a nickel-coated aluminum powder with a high specific surface area, wherein the nickel-coated aluminum powder comprises a modified porous aluminum powder and a cobalt-containing nickel layer; the cobalt-containing nickel layer is coated on the pore structure and outer surface of the modified porous aluminum powder; the modified porous aluminum powder comprises a porous aluminum powder and a conductive nanomaterial; the conductive nanomaterial is loaded on the pore structure and outer surface of the porous aluminum powder; the conductive nanomaterial comprises any one of graphene oxide and carboxylated carbon nanotubes. The reaction mechanism diagram for preparing the nickel-coated aluminum powder is shown as follows: Figure 1 shown.

[0025] In the second aspect, the present application provides a method for preparing nickel-coated aluminum powder with high specific surface area, such as Figure 2 As shown, including:

[0026] Under nitrogen protection, aluminum powder is added to a sodium hydroxide solution and etched for a first time to obtain porous aluminum powder;

[0027] Adding the conductive nanomaterial, surfactant and porous aluminum powder into the solvent, and ultrasonically stirring for a second time to obtain a modified porous aluminum powder dispersion;

[0028] adding a nickel source, a cobalt source, and a complexing agent to a modified porous aluminum powder dispersion, adjusting the pH to 7-8, and continuously stirring at the first temperature for a third time to form a nickel-cobalt-modified porous aluminum powder gel;

[0029] The nickel-cobalt-modified porous aluminum powder gel is dried at the second temperature for a fourth time, and then calcined at the third temperature in a nitrogen atmosphere for a fifth time to obtain the high specific surface area nickel-coated aluminum powder.

[0030] In a possible implementation, the particle size of the aluminum powder is in the range of 1 to 100 μm; and the concentration of the sodium hydroxide solution is in the range of 1 to 3 mol / L.

[0031] In one possible implementation, the mass ratio of the conductive nanomaterial, surfactant, porous aluminum powder, solvent, nickel source, cobalt source and complexing agent is: (1-3): (1-5): (40-60): (30-50): (5-15): (1-3): (5-10).

[0032] In a possible implementation, the surfactant includes at least one of cetyltrimethylammonium bromide, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, and polyethylene glycol octylphenyl ether.

[0033] In a possible implementation, the solvent includes at least one of deionized water, ethanol, and isopropanol.

[0034] In a possible implementation, the nickel source includes at least one of nickel acetate, nickel chloride, nickel sulfate, and nickel nitrate; and the cobalt source includes at least one of cobalt acetate, cobalt chloride, and cobalt nitrate.

[0035] In one possible implementation, the specific surface area can be further increased by combining platinum and palladium with nickel in the fcc lattice. Specifically, the cobalt source is further replaced with a platinum source or a palladium source; the platinum source includes at least one of chloroplatinic acid and platinum nitrate; and the palladium source includes at least one of palladium chloride and palladium nitrate.

[0036] The added platinum interacts more strongly with nickel, causing the atoms on the surface of the fcc lattice nickel layer to rearrange, forming more micropores or defects, thereby increasing the specific surface area; the added palladium inhibits the grain growth of the fcc lattice nickel, causing it to maintain a smaller grain size, thereby increasing the specific surface area; both can increase the specific surface area of ​​the final nickel-coated aluminum powder.

[0037] This application creatively prepares fcc lattice nickel in situ and simultaneously prepares palladium and platinum in situ. The in situ formation of palladium and platinum increases the specific surface area of ​​fcc lattice nickel in different dimensions, thereby facilitating the generation of high specific surface area nickel-coated aluminum powder.

[0038] In a possible implementation, the complexing agent includes any one of tartaric acid, oxalic acid, ethylenediaminetetraacetic acid, and acetylacetone.

[0039] In a possible implementation, the first duration is 30 to 50 minutes, the second duration is 10 to 15 minutes, the third duration is 1 to 3 hours, the fourth duration is 6 to 8 hours, and the fifth duration is 3 to 5 hours.

[0040] In a possible implementation, the first temperature is 60-80°C, the second temperature is 80-100°C, and the third temperature is 300-500°C.

[0041] In a third aspect, the present application provides a method for producing hydrogen, wherein the method uses nickel-coated aluminum powder with a high specific surface area as a reaction catalyst.

[0042] In one possible implementation, the hydrogen production method includes:

[0043] mixing high specific surface area nickel-coated aluminum powder and a binder in a set mass ratio to obtain a mixture;

[0044] The mixture is extruded to obtain a reaction catalyst of a specific shape;

[0045] The reaction catalyst is loaded into a fixed bed reactor, and the methanol aqueous solution is gasified and then introduced into the fixed bed reactor;

[0046] At a certain temperature and under the catalytic action of a reaction catalyst, the methanol in the methanol aqueous solution undergoes a reforming reaction with water to generate hydrogen.

[0047] In a possible implementation, the mass ratio of the high specific surface area nickel-coated aluminum powder to the binder is (80-90): (10-20).

[0048] In a possible implementation, the reaction catalyst may be in any one of a granular, spherical, and honeycomb shape.

[0049] In a possible implementation, the temperature of the reforming reaction between methanol and water is 200-400°C.

[0050] The following will describe in detail a high specific surface area nickel-coated aluminum powder and its preparation method provided by the present application in combination with different embodiments.

[0051] Example 1:

[0052] like Figure 2 As shown, a high specific surface area nickel-coated aluminum powder and a preparation method thereof include the following steps:

[0053] 1. Under nitrogen protection, add aluminum powder to 1 mol / L sodium hydroxide solution and etch for 30 minutes to obtain porous aluminum powder;

[0054] 2. Add 1 g of carboxylated carbon nanotubes, 2 g of hexadecyltrimethylammonium bromide, and 42 g of porous aluminum powder to 30 g of deionized water, and stir ultrasonically for 30 min to obtain a modified porous aluminum powder dispersion;

[0055] 3. Add 14 g nickel acetate, 1 g cobalt acetate and 10 g tartaric acid to the modified porous aluminum powder dispersion, adjust the pH to 7, and stir continuously at 60 ° C for 3 h to form a nickel-cobalt-modified porous aluminum powder gel;

[0056] 4. After drying the nickel-cobalt-modified porous aluminum powder gel at 80° C. for 7 h, calcining it at 300° C. in a nitrogen atmosphere for 5 h to obtain the high specific surface area nickel-coated aluminum powder.

[0057] The prepared nickel-coated aluminum powder is loaded onto an electrode material and catalyzed to produce hydrogen in an alkaline hydrogen production electrolyzer.

[0058] Example 2:

[0059] like Figure 2 As shown, a high specific surface area nickel-coated aluminum powder and a preparation method thereof include the following steps:

[0060] 1. Under nitrogen protection, add aluminum powder to 3 mol / L sodium hydroxide solution and etch for 10 minutes to obtain porous aluminum powder;

[0061] 2. Add 2 g of graphene oxide, 3 g of sodium lauryl sulfate, and 50 g of porous aluminum powder to 30 g of ethanol and stir ultrasonically for 40 min to obtain a modified porous aluminum powder dispersion;

[0062] 3. Add 8 g nickel chloride, 2 g cobalt nitrate and 5 g oxalic acid to the modified porous aluminum powder dispersion, adjust the pH to 7.5, and stir continuously at 70 ° C for 2 h to form a nickel-cobalt-modified porous aluminum powder gel;

[0063] 4. After drying the nickel-cobalt-modified porous aluminum powder gel at 90° C. for 8 h, calcining it at 400° C. in a nitrogen atmosphere for 4 h to obtain the high specific surface area nickel-coated aluminum powder.

[0064] The prepared nickel-coated aluminum powder was loaded onto the same electrode material as in Example 1, and catalytically produced hydrogen in the same alkaline hydrogen production electrolyzer as in Example 1.

[0065] Example 3:

[0066] like Figure 2 As shown, a high specific surface area nickel-coated aluminum powder and a preparation method thereof include the following steps:

[0067] 1. Under nitrogen protection, add aluminum powder to 2 mol / L sodium hydroxide solution and etch for 20 minutes to obtain porous aluminum powder;

[0068] 2. Add 3 g of graphene oxide, 5 g of sodium dodecylbenzenesulfonate and 45 g of porous aluminum powder to 25 g of isopropyl alcohol and stir ultrasonically for 50 min to obtain a modified porous aluminum powder dispersion;

[0069] 3. Add 11 g nickel sulfate, 3 g cobalt chloride and 8 g ethylenediaminetetraacetic acid to the modified porous aluminum powder dispersion, adjust the pH to 8, and stir continuously at 80 ° C for 1 hour to form a nickel-cobalt-modified porous aluminum powder gel;

[0070] 4. After drying the nickel-cobalt-modified porous aluminum powder gel at 100° C. for 6 h, calcining it at 500° C. in a nitrogen atmosphere for 3 h to obtain the high specific surface area nickel-coated aluminum powder.

[0071] The prepared nickel-coated aluminum powder was loaded onto the same electrode material as in Example 1, and catalytically produced hydrogen in the same alkaline hydrogen production electrolyzer as in Example 1.

[0072] Example 4:

[0073] like Figure 2 As shown, a high specific surface area nickel-coated aluminum powder and a preparation method thereof include the following steps:

[0074] 1. Under nitrogen protection, add aluminum powder to 1.5 mol / L sodium hydroxide solution and etch for 20 minutes to obtain porous aluminum powder;

[0075] 2. Add 1 g of carboxylated carbon nanotubes, 1 g of polyethylene glycol octylphenyl ether, and 46 g of porous aluminum powder to 34 g of deionized water and stir ultrasonically for 30 min to obtain a modified porous aluminum powder dispersion;

[0076] 3. Add 11 g nickel nitrate, 1 g cobalt acetate and 6 g acetylacetone to the modified porous aluminum powder dispersion, adjust the pH to 7, and stir continuously at 60 ° C for 1.5 h to form a nickel-cobalt-modified porous aluminum powder gel;

[0077] 4. After drying the nickel-cobalt-modified porous aluminum powder gel at 80° C. for 6.5 h, calcining it at 300° C. in a nitrogen atmosphere for 3.5 h to obtain the high specific surface area nickel-coated aluminum powder.

[0078] The prepared nickel-coated aluminum powder was loaded onto the same electrode material as in Example 1, and catalytically produced hydrogen in the same alkaline hydrogen production electrolyzer as in Example 1.

[0079] Example 5:

[0080] like Figure 2 As shown, a high specific surface area nickel-coated aluminum powder and a preparation method thereof include the following steps:

[0081] 1. Under nitrogen protection, add aluminum powder to 2.5 mol / L sodium hydroxide solution and etch for 15 minutes to obtain porous aluminum powder;

[0082] 2. Add 2 g of graphene oxide, 2 g of hexadecyltrimethylammonium bromide, and 42 g of porous aluminum powder to 36 g of ethanol and stir ultrasonically for 45 min to obtain a modified porous aluminum powder dispersion;

[0083] 3. Add 10 g nickel acetate, 1 g cobalt chloride and 7 g tartaric acid to the modified porous aluminum powder dispersion, adjust the pH to 8, and stir continuously at 75 ° C for 2.5 h to form a nickel-cobalt-modified porous aluminum powder gel;

[0084] 4. After drying the nickel-cobalt-modified porous aluminum powder gel at 90° C. for 7 h, calcining it at 400° C. in a nitrogen atmosphere for 4.5 h to obtain the high specific surface area nickel-coated aluminum powder.

[0085] The prepared nickel-coated aluminum powder was loaded onto the same electrode material as in Example 1, and catalytically produced hydrogen in the same alkaline hydrogen production electrolyzer as in Example 1.

[0086] Example 6:

[0087] like Figure 2 As shown, a high specific surface area nickel-coated aluminum powder and a preparation method thereof include the following steps:

[0088] 1. Under nitrogen protection, add aluminum powder to 3 mol / L sodium hydroxide solution and etch for 15 minutes to obtain porous aluminum powder;

[0089] 2. Add 3 g of carboxylated carbon nanotubes, 4 g of sodium lauryl sulfate, and 42 g of porous aluminum powder to 35 g of isopropyl alcohol and stir ultrasonically for 50 min to obtain a modified porous aluminum powder dispersion;

[0090] 3. Add 10 g nickel chloride, 2 g cobalt nitrate and 4 g oxalic acid to the modified porous aluminum powder dispersion, adjust the pH to 7, and stir continuously at 70 ° C for 2 h to form a nickel-cobalt-modified porous aluminum powder gel;

[0091] 4. After drying the nickel-cobalt-modified porous aluminum powder gel at 100° C. for 6 h, calcining it at 500° C. in a nitrogen atmosphere for 3.5 h to obtain the high specific surface area nickel-coated aluminum powder.

[0092] The prepared nickel-coated aluminum powder was loaded onto the same electrode material as in Example 1, and catalytically produced hydrogen in the same alkaline hydrogen production electrolyzer as in Example 1.

[0093] Comparative Example 1:

[0094] A high specific surface area nickel-coated aluminum powder and a preparation method thereof, comprising the following steps:

[0095] 1. Under nitrogen protection, add aluminum powder to 1 mol / L sodium hydroxide solution and etch for 30 minutes to obtain porous aluminum powder;

[0096] 2. Add 2 g of hexadecyltrimethylammonium bromide and 43 g of porous aluminum powder to 30 g of deionized water and stir ultrasonically for 30 min to obtain a modified porous aluminum powder dispersion;

[0097] 3. Add 14 g nickel acetate, 1 g cobalt acetate and 10 g tartaric acid to the modified porous aluminum powder dispersion, adjust the pH to 7, and stir continuously at 60 ° C for 3 h to form a nickel-cobalt-modified porous aluminum powder gel;

[0098] 4. After drying the nickel-cobalt-modified porous aluminum powder gel at 80° C. for 7 h, calcining it at 300° C. in a nitrogen atmosphere for 5 h to obtain the high specific surface area nickel-coated aluminum powder.

[0099] The prepared nickel-coated aluminum powder was loaded onto the same electrode material as in Example 1, and catalytically produced hydrogen in the same alkaline hydrogen production electrolyzer as in Example 1.

[0100] Comparative Example 2:

[0101] A nickel-coated aluminum powder and a preparation method thereof, comprising the following steps:

[0102] 1. Add 3 g of graphene oxide, 5 g of sodium dodecylbenzenesulfonate and 45 g of aluminum powder to 25 g of isopropyl alcohol and stir ultrasonically for 50 min to obtain an aluminum powder dispersion;

[0103] 2. Add 11g nickel sulfate, 3g cobalt chloride and 8g ethylenediaminetetraacetic acid to the aluminum powder dispersion, adjust the pH to 8, and stir continuously at 80°C for 1h to form a nickel-cobalt-aluminum powder gel;

[0104] 3. After drying the nickel-cobalt-aluminum powder gel at 100° C. for 6 h, calcining it at 500° C. in a nitrogen atmosphere for 3 h to obtain the nickel-coated aluminum powder.

[0105] The prepared nickel-coated aluminum powder was loaded onto the same electrode material as in Example 1, and catalytically produced hydrogen in the same alkaline hydrogen production electrolyzer as in Example 1.

[0106] Comparative Example 3:

[0107] A nickel-coated aluminum powder and a preparation method thereof, comprising the following steps:

[0108] 1. Add 4g of sodium lauryl sulfate and 45g of aluminum powder to 35g of isopropyl alcohol and stir ultrasonically for 50min to obtain an aluminum powder dispersion;

[0109] 2. Add 10g nickel chloride, 2g cobalt nitrate and 4g oxalic acid to the aluminum powder dispersion, adjust the pH to 7, and stir continuously at 70°C for 2h to form a nickel-cobalt-aluminum powder gel;

[0110] 3. After drying the nickel-cobalt-aluminum powder gel at 100° C. for 6 h, calcining it at 500° C. in a nitrogen atmosphere for 3.5 h to obtain the nickel-coated aluminum powder.

[0111] The prepared nickel-coated aluminum powder was loaded onto the same electrode material as in Example 1, and catalytically produced hydrogen in the same alkaline hydrogen production electrolyzer as in Example 1.

[0112] The specific surface area values ​​of the nickel-coated aluminum powders prepared in the examples and comparative examples were tested using the BET specific surface area detection method.

[0113] The resistance of the nickel-coated aluminum powders prepared in the examples and comparative examples was tested using a resistance tester to reflect their electrical conductivity.

[0114] The electromagnetic shielding effectiveness testing device was used to test the electromagnetic shielding values ​​of the nickel-clad aluminum powders prepared in the examples and comparative examples.

[0115] The volume of hydrogen produced by the same mass of nickel-coated aluminum powder in the alkaline hydrogen production electrolyzer under the same reaction conditions and in the same time is collected and measured to reflect the strength of its catalytic hydrogen production ability.

[0116] The test results of the above tests are shown in Table 1.

[0117] Table 1 Test results of nickel-coated aluminum powder prepared in Examples and Comparative Examples

[0118]

[0119] As shown in Table 1, the specific surface area, electromagnetic shielding value and hydrogen production efficiency of Examples 1 to 6 are significantly higher than those of Comparative Examples 1 to 3; at the same time, the resistance values ​​of Examples 1 to 6 are significantly lower than those of Comparative Examples 1 to 3.

[0120] This is because the nickel-coated aluminum powder prepared in Examples 1-6 has numerous pores and channels, significantly increasing its specific surface area and serving as active sites for catalytic reactions. Furthermore, the nickel layer contains cobalt, which further forms bimetallic active sites with the nickel, enhancing the catalytic performance of the nickel-coated aluminum powder. Furthermore, the cobalt-containing nickel layer and aluminum themselves possess excellent electrical conductivity. When combined with the conductive nanomaterials with conjugated electron structures, the conductive network is further improved and electron transport pathways are enriched, significantly enhancing the conductivity and electromagnetic shielding performance of the nickel-coated aluminum powder.

[0121] In contrast, in Comparative Example 3, no conductive nanomaterials were added and the aluminum powder was not etched, so a porous structure could not be formed, which ultimately resulted in the nickel-coated aluminum powder having the smallest specific surface area, and the worst conductivity and electromagnetic shielding performance.

[0122] In Comparative Example 2, conductive nanomaterials were added, but the aluminum powder was not etched to form a porous structure. Therefore, the amount of conductive nanomaterials adsorbed on the surface of the aluminum powder was relatively small. After the nickel layer, aluminum and conductive nanomaterials were compounded, the conductive network formed was not perfect. Finally, the nickel-coated aluminum powder had certain conductivity and electromagnetic shielding properties, but they were still weak.

[0123] In Comparative Example 1, the aluminum powder was etched to form a porous structure, and the nickel-coated aluminum powder obtained had a relatively high specific surface area. However, since no conductive nanomaterials were added, the conductivity and electromagnetic shielding performance were relatively weak.

[0124] The above results show and describe the basic principles and main features of this application as well as the advantages of this application.

[0125] Those skilled in the art should understand that the present application is not limited to the above-described embodiments. The above-described embodiments and descriptions are merely illustrative of the principles of the present application. Various changes and improvements may be made to the present application without departing from the spirit and scope of the present application. Such changes and improvements are intended to fall within the scope of the present application. The scope of protection claimed in the present application is defined by the equivalents of the appended claims.

Claims

1. A high specific surface area nickel-coated aluminum powder, characterized in that: The nickel-coated aluminum powder includes modified porous aluminum powder and a cobalt-containing nickel layer; the cobalt-containing nickel layer is coated on the pore structure and outer surface of the modified porous aluminum powder; the modified porous aluminum powder includes porous aluminum powder and a conductive nanomaterial; the conductive nanomaterial is loaded on the pore structure and outer surface of the porous aluminum powder; the conductive nanomaterial includes any one of graphene oxide and carboxylated carbon nanotubes.

2. The method for preparing a high specific surface area nickel-coated aluminum powder according to claim 1, wherein: include: Under nitrogen protection, aluminum powder is added to a sodium hydroxide solution and etched for a first time to obtain porous aluminum powder; Adding the conductive nanomaterial, surfactant and porous aluminum powder into the solvent, and ultrasonically stirring for a second time to obtain a modified porous aluminum powder dispersion; adding a nickel source, a cobalt source, and a complexing agent to a modified porous aluminum powder dispersion, adjusting the pH to 7-8, and continuously stirring at the first temperature for a third time to form a nickel-cobalt-modified porous aluminum powder gel; The nickel-cobalt-modified porous aluminum powder gel is dried at the second temperature for a fourth time, and then calcined at the third temperature in a nitrogen atmosphere for a fifth time to obtain the high specific surface area nickel-coated aluminum powder.

3. The method for preparing a high specific surface area nickel-coated aluminum powder according to claim 2, wherein: The particle size range of the aluminum powder is 1-100 μm; the concentration of the sodium hydroxide solution is 1-3 mol / L.

4. The method for preparing a high specific surface area nickel-coated aluminum powder according to claim 2, wherein: The mass ratio of the conductive nanomaterial, surfactant, porous aluminum powder, solvent, nickel source, cobalt source and complexing agent is: (1-3): (1-5): (40-60): (30-50): (5-15): (1-3): (5-10).

5. The method for preparing a high specific surface area nickel-coated aluminum powder according to claim 2, wherein: The surfactant includes at least one of cetyltrimethylammonium bromide, sodium lauryl sulfate, sodium dodecylbenzenesulfonate and polyethylene glycol octylphenyl ether.

6. The method for preparing a high specific surface area nickel-coated aluminum powder according to claim 2, wherein: The solvent includes at least one of deionized water, ethanol and isopropyl alcohol.

7. The method for preparing a high specific surface area nickel-coated aluminum powder according to claim 2, wherein: The nickel source includes at least one of nickel acetate, nickel chloride, nickel sulfate and nickel nitrate; the cobalt source includes at least one of cobalt acetate, cobalt chloride and cobalt nitrate.

8. The method for preparing a high specific surface area nickel-coated aluminum powder according to claim 2, wherein: The complexing agent includes any one of tartaric acid, oxalic acid, ethylenediaminetetraacetic acid and acetylacetone.

9. The method for preparing a high specific surface area nickel-coated aluminum powder according to claim 2, wherein: The first duration is 10~30 minutes, the second duration is 30~60 minutes, the third duration is 1~3 hours, the fourth duration is 6~8 hours, and the fifth duration is 3~5 hours; the first temperature is 60~80℃, the second temperature is 80~100℃, and the third temperature is 300~500℃.

10. A method for producing hydrogen, characterized in that: The hydrogen production method uses the high specific surface area nickel-coated aluminum powder described in claim 1 as a reaction catalyst.

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