Aluminum-based hydrogen production material and preparation process thereof

Abstract

The present invention belongs to the field of energy technology, and specifically relates to an aluminum-based hydrogen-producing material and a preparation process thereof. The aluminum-based hydrogen-producing material provided by the present invention includes aluminum powder, a composite activator, an activated metal and a salt; the composite activator is a composite material prepared from antimony trioxide, vanadium pentoxide and modified carbon nanotubes. The present invention uses antimony trioxide, vanadium pentoxide and modified carbon nanotubes to prepare a composite material as a composite activator, which makes the aluminum oxide film structure loose and cracked, destroys the integrity of the oxide film, accelerates electron transfer, and improves the hydrogen production efficiency of the aluminum-based hydrogen-producing material; nickel and cobalt are used to modify the acidified carbon nanotubes, and the hydrogen generation energy barrier is reduced by adsorbing nickel in the carbon nanotubes to improve the hydrogen production efficiency, and the oxide film on the surface of the aluminum powder is promoted to dissolve by adsorbing cobalt in the carbon nanotubes, thereby improving the reaction activity of the aluminum powder.

Description

Technical Field

[0001] This invention belongs to the field of energy technology, specifically relating to an aluminum-based hydrogen production material and its preparation process. Background Technology

[0002] With the continuous depletion of global fossil energy reserves and the increasing emphasis placed on carbon emissions by countries around the world, the development of new energy sources has become a focus of political and economic attention in various countries. Hydrogen energy is a globally recognized clean energy source with advantages such as abundant reserves, pollution-free combustion, and high calorific value, and is considered to be the clean energy source with the greatest development potential.

[0003] Hydrogen can be extracted from water or hydrocarbons using reactive metals. The reaction is rapid and can be quantitatively extracted anytime, anywhere, according to demand. Aluminum, as the most abundant metallic element in the Earth's crust, is widely available, relatively inexpensive, has low density, and possesses high energy density, making aluminum hydrolysis hydrogen production technology one of the most competitive hydrogen production technologies. However, due to aluminum's high reactivity, a dense oxide film immediately forms on its surface when exposed to air, preventing the reaction between aluminum and water. Therefore, removing this oxide layer is crucial for the development and application of aluminum hydrolysis hydrogen production technology.

[0004] Currently, there are two main methods to address the oxide film on aluminum: one is aluminum powder alloying and activation, and the other is creating an alkaline or acidic hydrolysis environment. However, the addition of alloying elements reduces the energy density of the hydrolyzed aluminum material, while the acidic or alkaline hydrolysis environment corrodes hydrogen production equipment. Furthermore, under alkaline conditions, the pH value of the solution has a significant impact on the hydrogen production rate. When the pH value is too high, the hydrogen production rate is too fast, requiring the addition of storage tanks to store the hydrogen, which carries the risk of hydrogen leakage.

[0005] For example, patent application CN110872662A discloses a hydrolysis hydrogen production aluminum substrate. This aluminum substrate alloy is made by melting multiple elemental metals, including magnesium, gallium, indium, tin, bismuth, and aluminum. Although the aluminum substrate is made by melting elemental metals, which simplifies the process of hydrogen production substrate and reduces the content of trace elements, the addition of alloying elements will directly increase the total mass of the material. However, elements such as gallium, indium, tin, and bismuth do not participate in the hydrogen production reaction themselves, and the alloying elements may change the original aluminum-water reaction mechanism, introduce a more complex reaction path or form intermediate products, resulting in a decrease in the hydrogen production efficiency and energy density of the aluminum substrate.

[0006] For example, patent application CN107459018A discloses an aluminum-based composite hydrogen production agent, including formulation A, formulation B, and formulation C. Formulation A mainly consists of aluminum powder and sodium hydroxide, formulation B mainly consists of aluminum powder and sodium bicarbonate, and formulation C mainly consists of aluminum powder and calcium oxide. Although this composite hydrogen production agent alleviates the problem of unstable hydrogen production rate and quantity during hydrogen production, the alkali added to its hydrogen production materials can corrode hydrogen production equipment, increase maintenance costs, and shorten the service life of hydrogen production equipment. In addition to generating hydrogen, the reaction between aluminum and alkali solution also produces a large amount of metal oxides or hydroxide precipitates (such as Al(OH)3). If these byproducts are not properly handled, they may clog system pipelines, affect the continuity of hydrogen production operations, and reduce the hydrogen production rate. Summary of the Invention

[0007] In order to solve the technical problems of low hydrogen production capacity and rate and equipment corrosion in the above-mentioned related technologies, the present invention aims to provide an aluminum-based hydrogen production material and its preparation process.

[0008] To achieve the above objectives, the technology of the present invention is as follows:

[0009] An aluminum-based hydrogen production material comprises the following components in parts by weight:

[0010] The mixture contains 60-80 parts aluminum powder, 10-15 parts composite activator, 3-6 parts activated metal, and 5-8 parts salt; the composite activator is a composite material prepared from antimony trioxide, vanadium pentoxide, and modified carbon nanotubes.

[0011] This invention incorporates a composite activator into hydrogen production materials to reduce the amount of alloying elements added, effectively avoiding the reduction in energy density of aluminum-based hydrogen production materials caused by alloying elements. A composite material is prepared using antimony trioxide, vanadium pentoxide, and modified carbon nanotubes. Antimony ions and vanadium oxide ions have small radii and strong polarization capabilities, allowing them to penetrate the micropores or defects of the alumina film and combine with cations in the alumina to form more easily soluble composite oxides. This causes the alumina film structure to become loose and cracked, compromising the integrity of the oxide film. Furthermore, antimony ions and vanadium oxide ions exhibit a significant potential difference with aluminum. The modified carbon nanotubes can form a micro-battery reaction with aluminum in water, accelerating electron transfer. Simultaneously, the activated metal can form a low-melting-point alloy phase with aluminum, weakening the density of the oxide film and exposing the aluminum, thus improving the hydrogen production efficiency of the aluminum-based hydrogen production material. The modified carbon nanotubes, coated on the surface of the aluminum powder during ball milling, can act as electron transport channels, reducing the charge transfer resistance at the aluminum-solution interface and accelerating the hydrolysis of aluminum powder to produce hydrogen. Their porous structure can adsorb water molecules and rapidly diffuse them to the aluminum powder surface, solving the mass transfer obstruction problem caused by aluminum powder agglomeration in the later stages of the reaction, effectively improving the hydrogen production rate. Furthermore, the aluminum-based hydrogen production material provided by this invention does not contain any added acid or alkali, effectively avoiding corrosion of the hydrogen production equipment.

[0012] Furthermore, the preparation method of the composite activator is as follows: antimony trioxide and vanadium pentoxide are added to sulfuric acid solution, stirred and dissolved, modified carbon nanotubes are added, stirred and sonicated, potassium chloride solution is added, stirring is continued for 4-4.5 hours, solid-liquid separation is performed, and the mixture is washed and dried to obtain the composite activator.

[0013] The above technical solution involves dissolving antimony trioxide and vanadium pentoxide in sulfate to generate soluble antimony salt (Sb₂(SO₄)₃) and vanadium oxide sulfate (VO₂SO₄). After adding modified carbon nanotubes and subjecting them to stirring and ultrasonic treatment, the bundled aggregation of carbon nanotubes is broken, allowing them to fully expand in the solution. Simultaneously, antimony ions and vanadium oxide ions can combine with the hydroxyl groups on the surface of the modified carbon nanotubes through electrostatic interactions, achieving a uniform loading of metal ions on the carbon nanotube surface. The potassium and chloride ions in the potassium chloride solution increase the ionic strength of the solution, weakening the van der Waals forces between carbon nanotubes through electrostatic shielding, preventing their aggregation. At the same time, chloride ions can pre-form stable ion pairs with antimony ions and vanadium oxide ions, avoiding the precipitation and crystallization of metal ions during drying and ensuring a uniform distribution of metal ions.

[0014] Furthermore, the mass ratio of antimony trioxide, vanadium pentoxide, and modified carbon nanotubes is 0.23-0.36:0.09-0.17:1.

[0015] By controlling the mass ratio of antimony trioxide, vanadium pentoxide, and modified carbon nanotubes through the above technical solution, excessive amounts of antimony trioxide and vanadium pentoxide can be avoided from clogging the pore structure of carbon nanotubes, affecting the adsorption and diffusion of water molecules by carbon nanotubes, and thus affecting hydrogen production efficiency and hydrogen production.

[0016] Furthermore, the mass ratio of antimony trioxide, vanadium pentoxide, and modified carbon nanotubes is 0.28-0.32:0.10-0.15:1.

[0017] Furthermore, the sulfuric acid solution has a mass percentage of 30%-40%; and the potassium chloride solution has a concentration of 1-1.5 mol / L.

[0018] Furthermore, the ultrasonic frequency of the stirring ultrasound is 45-60kHz, and the stirring ultrasound time is 6-8h.

[0019] Furthermore, the modified carbon nanotubes are prepared by: placing carbon nanotubes in an acid solution, ultrasonically dispersing, centrifuging, washing, drying, and grinding to obtain acidified carbon nanotubes; placing the acidified carbon nanotubes in a titanium precursor mixture, ultrasonically dispersing, adding a mixed solution of nickel nitrate and cobalt nitrate dropwise while stirring, continuing to stir for 1.2-1.6 hours, stopping stirring, aging for 2-3 hours, drying, grinding, and calcining to obtain modified carbon nanotubes.

[0020] Through the above technical solution, the H in the acid solution during the acidification process of carbon nanotubes is reduced. + The functional groups on the surface of carbon nanotubes can be protonated to introduce hydroxyl groups, enhancing their electrostatic attraction to metal ions and making the metal ions more firmly anchored on the surface of carbon nanotubes, effectively improving the electron transfer efficiency during the reaction of aluminum and water. By adsorbing nickel in carbon nanotubes, the energy barrier for hydrogen generation is lowered, improving hydrogen production efficiency. By adsorbing cobalt in carbon nanotubes, the oxide film on the surface of aluminum powder is dissolved, improving the reactivity of aluminum powder. The porous structure of carbon nanotubes can adsorb aluminum powder, preventing the aluminum powder from agglomerating due to overheating or product encapsulation, and maintaining the continuity of the reaction interface.

[0021] Furthermore, the sum of the masses of nickel nitrate and cobalt nitrate in the mixed solution of nickel nitrate and cobalt nitrate is 3%-5% of the mass of the acidified carbon nanotubes.

[0022] By controlling the amount of nickel and cobalt used in the above-mentioned technical solution, the influence of modified carbon nanotubes on the hydrogen production efficiency of aluminum-based hydrogen production materials was controlled. The study found that when the amount of nickel and cobalt was small, the number of metal ions adsorbed in the carbon nanotubes was low, and the impact on the electron transfer efficiency of the carbon nanotubes was small, resulting in a small increase in hydrogen production efficiency. When the amount of nickel and cobalt increased, the hydrogen production rate of the aluminum-based hydrogen production material initially increased sharply, but then decreased sharply. This is because excessive nickel and cobalt blocked the pore structure of the carbon nanotubes, blocked the conductive network of the carbon nanotubes, reduced the electron transfer efficiency, and the excessive nickel and cobalt covered the aluminum surface, hindering the contact between aluminum and water, resulting in a decrease in hydrogen production and hydrogen production efficiency.

[0023] Furthermore, the acid solution is a mixed solution of concentrated sulfuric acid and concentrated nitric acid, with a volume ratio of 2-3:1; the ultrasonic dispersion is performed at a frequency of 30-40 kHz for 2-3 hours.

[0024] Furthermore, the titanium precursor solution is prepared by mixing anhydrous ethanol, deionized water, and concentrated nitric acid, then adding tetrabutyl titanate and stirring for 1.0-1.5 hours to obtain the titanium precursor solution; the volume ratio of anhydrous ethanol, deionized water, concentrated nitric acid, and tetrabutyl titanate is 70-73:7-10:3-6:25:30.

[0025] Furthermore, the method for preparing the mixed solution of nickel nitrate and cobalt nitrate is as follows: anhydrous ethanol and deionized water are mixed evenly at a volume ratio of 5:1, nickel nitrate and cobalt nitrate are added while stirring, the pH value of the solution is adjusted to 2-3, and stirring is continued for 3-3.5 hours to obtain the mixed solution of nickel nitrate and cobalt nitrate; the mass ratio of nickel nitrate and cobalt nitrate is 3-5:7-9.

[0026] Furthermore, the calcination temperature is 500-600℃, the heating rate is 15-20℃ / min, and the calcination time is 3-4h.

[0027] Furthermore, the activated metal is one of magnesium, zinc, manganese, and chromium.

[0028] Furthermore, the salt is one of sodium chloride, potassium chloride, and magnesium chloride.

[0029] The present invention also provides a preparation process for the aluminum-based hydrogen production material, specifically: aluminum powder, composite activator, activated metal and salt are mixed evenly, and ball milling is performed under the protection of inert gas, with a ball-to-material ratio of 10-20:1, a ball milling speed of 300-400 rpm and a ball milling time of 20-24 h.

[0030] Through the above technical solution, the ball milling process is used to adsorb and encapsulate the aluminum powder with the composite activator. During the ball milling process, the activated metal will also form a local alloy phase with the aluminum, which weakens the stability of the oxide film. At the same time, the ball milling process is carried out under the protection of inert gas, which can effectively prevent the aluminum powder from oxidizing during the mechanical activation process and ensure the chemical stability of the material.

[0031] Compared with existing technologies, the aluminum-based hydrogen production material and its preparation process provided by this invention have the following technical advantages:

[0032] (1) The present invention uses aluminum powder, composite activator, activated metal and salt to form hydrogen production material. Through the synergistic effect of each component, efficient and rapid hydrogen production is achieved, which effectively improves the hydrogen production rate and reduces equipment corrosion.

[0033] (2) The present invention uses antimony trioxide, vanadium pentoxide and modified carbon nanotubes to prepare a composite material as a composite activator, which makes the structure of the alumina film loose and cracked, destroys the integrity of the oxide film, accelerates electron transfer, and improves the hydrogen production efficiency of aluminum-based hydrogen production materials.

[0034] (3) In this invention, nickel and cobalt are used to modify the acidified carbon nanotubes. By adsorbing nickel in the carbon nanotubes, the energy barrier for hydrogen generation is reduced and the hydrogen production efficiency is improved. By adsorbing cobalt in the carbon nanotubes, the oxide film on the surface of aluminum powder is dissolved and the reactivity of aluminum powder is improved. Attached Figure Description

[0035] Figure 1 The hydrogen production curves are for the aluminum-based hydrogen production materials prepared in Examples 1-5.

[0036] Figure 2 The hydrogen production rate curves are for the aluminum-based hydrogen production materials prepared in Examples 1-5.

[0037] Figure 3The hydrogen production curves of the aluminum-based hydrogen production materials obtained in Example 4, Comparative Examples 1-5 are shown.

[0038] Figure 4 The hydrogen production rate curves of the aluminum-based hydrogen production materials prepared in Example 4, Comparative Examples 1-5 are shown.

[0039] Figure 5 The image shows the XRD pattern of the composite activator prepared in Example 4. Detailed Implementation

[0040] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments. Those skilled in the art can make various modifications based on the fundamental principles of the present invention, but all modifications that do not depart from the fundamental principles of the present invention are within its scope.

[0041] Preparation Example 1

[0042] The modified carbon nanotubes were prepared as follows: 100g of carbon nanotubes were placed in 500mL of acid solution (concentrated sulfuric acid and concentrated nitric acid were mixed at a volume ratio of 2:1), ultrasonically dispersed at a frequency of 30kHz for 3h, centrifuged, and the lower precipitate was washed with deionized water until the washing solution was neutral. The precipitate was then placed in a vacuum drying oven and dried at 90℃ for 12h. After grinding, acidified carbon nanotubes were obtained. The acidified carbon nanotubes were placed in 1000mL of titanium precursor mixture and ultrasonically dispersed at a frequency of 30kHz for 3h. A mixed solution of nickel nitrate and cobalt nitrate was added dropwise while stirring (the sum of the masses of nickel nitrate and cobalt nitrate in the mixed solution of nickel nitrate and cobalt nitrate was 3% of the mass of the acidified carbon nanotubes). Stirring was continued for 1.2h, stirring was stopped, and the mixture was aged for 2h. The mixture was then placed in a vacuum drying oven and dried at 80℃ for 15h. The mixture was ground into powder and then calcined in a muffle furnace at a heating rate of 15℃ / min to 500℃ for 4h. After cooling, modified carbon nanotubes were obtained.

[0043] The titanium precursor solution is prepared by mixing 700 mL of anhydrous ethanol, 100 mL of deionized water and 30 mL of concentrated nitric acid, then adding 250 mL of tetrabutyl titanate and stirring for 1.0 h to obtain the titanium precursor solution.

[0044] The method for preparing the mixed solution of nickel nitrate and cobalt nitrate is as follows: anhydrous ethanol and deionized water are mixed evenly at a volume ratio of 5:1, and nickel nitrate and cobalt nitrate (mass ratio of nickel nitrate and cobalt nitrate is 3:7) are added while stirring. The pH value of the solution is adjusted to 2, and stirring is continued for 3 hours to obtain the mixed solution of nickel nitrate and cobalt nitrate.

[0045] Preparation Example 2

[0046] The modified carbon nanotubes were prepared as follows: 100g of carbon nanotubes were placed in 500mL of acid solution (concentrated sulfuric acid and concentrated nitric acid were mixed at a volume ratio of 3:1), ultrasonically dispersed at a frequency of 40kHz for 2h, centrifuged, and the lower precipitate was washed with deionized water until the washing solution was neutral. The precipitate was then placed in a vacuum drying oven and dried at 100℃ for 10h. After grinding, acidified carbon nanotubes were obtained. The acidified carbon nanotubes were placed in 1000mL of titanium precursor mixture and ultrasonically dispersed at a frequency of 40kHz for 2h. A mixed solution of nickel nitrate and cobalt nitrate was added dropwise while stirring (the sum of the masses of nickel nitrate and cobalt nitrate in the mixed solution of nickel nitrate and cobalt nitrate was 5% of the mass of the acidified carbon nanotubes). Stirring was continued for 1.6h, stirring was stopped, and the mixture was aged for 3h. The mixture was then placed in a vacuum drying oven and dried at 90℃ for 12h. The mixture was ground into powder and then calcined in a muffle furnace at a heating rate of 20℃ / min to 600℃ for 3h. After cooling, modified carbon nanotubes were obtained.

[0047] The titanium precursor solution is prepared by mixing 730 mL of anhydrous ethanol, 70 mL of deionized water and 60 mL of concentrated nitric acid, then adding 300 mL of tetrabutyl titanate and stirring for 1.5 h to obtain the titanium precursor solution.

[0048] The method for preparing the mixed solution of nickel nitrate and cobalt nitrate is as follows: anhydrous ethanol and deionized water are mixed evenly at a volume ratio of 5:1, and nickel nitrate and cobalt nitrate (mass ratio of nickel nitrate and cobalt nitrate is 5:9) are added while stirring. The pH value of the solution is adjusted to 3, and stirring is continued for 3.5 hours to obtain the mixed solution of nickel nitrate and cobalt nitrate.

[0049] Preparation Example 3

[0050] The modified carbon nanotubes were prepared as follows: 100g of carbon nanotubes were placed in 500mL of acid solution (concentrated sulfuric acid and concentrated nitric acid were mixed at a volume ratio of 2.5:1) and ultrasonically dispersed at a frequency of 35kHz for 2.8h. After centrifugation, the lower precipitate was washed with deionized water until the washing solution was neutral. The precipitate was then dried in a vacuum drying oven at 95℃ for 11h. After grinding, acidified carbon nanotubes were obtained. The acidified carbon nanotubes were then placed in 1000mL of a titanium precursor mixture and ultrasonically dispersed at a frequency of 35kHz. Under the conditions of ultrasonic dispersion for 2.5 h, a mixed solution of nickel nitrate and cobalt nitrate was added dropwise while stirring (the sum of the masses of nickel nitrate and cobalt nitrate in the mixed solution of nickel nitrate and cobalt nitrate was 4% of the mass of the acidified carbon nanotubes). Stirring was continued for 1.5 h, then stirring was stopped, and the mixture was aged for 2.5 h. The mixture was then placed in a vacuum drying oven and dried at 85 °C for 14 h. The mixture was ground into powder and then calcined in a muffle furnace at a heating rate of 18 °C / min to 580 °C for 3.5 h. After cooling, the modified carbon nanotubes were obtained.

[0051] The titanium precursor solution is prepared by mixing 720 mL of anhydrous ethanol, 80 mL of deionized water and 50 mL of concentrated nitric acid, then adding 280 mL of tetrabutyl titanate and stirring for 1.3 h to obtain the titanium precursor solution.

[0052] The method for preparing the mixed solution of nickel nitrate and cobalt nitrate is as follows: anhydrous ethanol and deionized water are mixed evenly at a volume ratio of 5:1, and nickel nitrate and cobalt nitrate (mass ratio of nickel nitrate and cobalt nitrate is 4:9) are added while stirring. The pH value of the solution is adjusted to 2.5, and stirring is continued for 3.3 hours to obtain the mixed solution of nickel nitrate and cobalt nitrate.

[0053] Preparation Example 4

[0054] The preparation method of the composite activator is as follows: 23g of antimony trioxide and 9g of vanadium pentoxide are added to 150mL of 30% sulfuric acid solution and stirred to dissolve. 100g of modified carbon nanotubes are added, and the solution is then stirred and sonicated at a frequency of 45kHz for 8h. 10mL of 1.5mol / L potassium chloride solution is slowly added, and stirring is continued for 4h. The solid sample is obtained by centrifugation. The solid sample is washed 5 times with deionized water and anhydrous ethanol, respectively, and then dried in a vacuum drying oven at 60℃ for 12h to obtain the composite activator.

[0055] The modified carbon nanotubes used in this preparation example were obtained in Preparation Example 1.

[0056] Preparation Example 5

[0057] The preparation method of the composite activator is as follows: 36g of antimony trioxide and 17g of vanadium pentoxide are added to 150mL of 40% sulfuric acid solution and stirred to dissolve. 100g of modified carbon nanotubes are added, and the solution is then stirred and sonicated at a frequency of 60kHz for 6h. 20mL of 1mol / L potassium chloride solution is slowly added, and stirring is continued for 4.5h. The solid sample is obtained by centrifugation. The solid sample is washed 5 times with deionized water and anhydrous ethanol, respectively, and then dried in a vacuum drying oven at 70℃ for 10h to obtain the composite activator.

[0058] The modified carbon nanotubes used in this preparation example were prepared in Preparation Example 2.

[0059] Preparation Example 6

[0060] The preparation method of the composite activator is as follows: 30g of antimony trioxide and 12g of vanadium pentoxide are added to 150mL of 35% sulfuric acid solution and stirred to dissolve. 100g of modified carbon nanotubes are added, and the solution is then stirred and sonicated at a frequency of 55kHz for 7h. 15mL of 1.2mol / L potassium chloride solution is slowly added, and stirring is continued for 4.3h. The solid sample is obtained by centrifugation. The solid sample is washed 5 times with deionized water and anhydrous ethanol, respectively, and then dried in a vacuum drying oven at 65℃ for 11h to obtain the composite activator.

[0061] The modified carbon nanotubes used in this preparation example were prepared in Preparation Example 3.

[0062] Example 1

[0063] An aluminum-based hydrogen production material comprises the following components in parts by weight: 60 parts aluminum powder, 15 parts composite activator, 6 parts magnesium, and 8 parts sodium chloride.

[0064] The preparation process of aluminum-based hydrogen production materials is as follows: aluminum powder, composite activator, activated metal and salt are mixed evenly and ball-milled under the protection of inert gas. The ball-to-material ratio is 10:1, the ball milling speed is 300 rpm and the ball milling time is 24 h.

[0065] The composite activator described in this embodiment was prepared in Preparation Example 4.

[0066] Example 2

[0067] An aluminum-based hydrogen production material comprises the following components in parts by weight: 80 parts aluminum powder, 10 parts composite activator, 3 parts zinc, and 5 parts magnesium chloride.

[0068] The preparation process of aluminum-based hydrogen production materials is as follows: aluminum powder, composite activator, activated metal and salt are mixed evenly and ball-milled under the protection of inert gas. The ball-to-material ratio is 20:1, the ball milling speed is 400 rpm and the ball milling time is 20 h.

[0069] The composite activator described in this embodiment was prepared in Preparation Example 5.

[0070] Example 3

[0071] An aluminum-based hydrogen production material comprises the following components in parts by weight: 70 parts aluminum powder, 12 parts composite activator, 4 parts manganese, and 7 parts potassium chloride.

[0072] The preparation process of aluminum-based hydrogen production materials is as follows: aluminum powder, composite activator, activated metal and salt are mixed evenly and ball-milled under the protection of inert gas. The ball-to-material ratio is 15:1, the ball milling speed is 350 rpm and the ball milling time is 22 h.

[0073] The composite activator described in this embodiment was prepared in Preparation Example 6.

[0074] Example 4

[0075] The aluminum-based hydrogen production material and its preparation process described in this embodiment are similar to those in Embodiment 3. The difference between this embodiment and Embodiment 3 is as follows: The preparation method of the composite activator in this embodiment is as follows: 31g of antimony trioxide and 14g of vanadium pentoxide are added to 150mL of 35% sulfuric acid solution and stirred to dissolve. 100g of modified carbon nanotubes are added, and the solution is then stirred and sonicated at a frequency of 55kHz for 7h. 15mL of 1.2mol / L potassium chloride solution is slowly added, and stirring is continued for 4.3h. The solid sample is obtained by centrifugation and washed 5 times with deionized water and anhydrous ethanol, respectively. The solid sample is then placed in a vacuum drying oven and dried at 65℃ for 11h to obtain the composite activator.

[0076] The modified carbon nanotubes used in this preparation example were prepared in Preparation Example 3.

[0077] Example 5

[0078] The aluminum-based hydrogen production material and its preparation method described in this embodiment are similar to those in Embodiment 3. The difference between this embodiment and Embodiment 3 is as follows: The preparation method of the modified carbon nanotubes in this embodiment is as follows: 100g of carbon nanotubes are placed in 500mL of acid solution (concentrated sulfuric acid and concentrated nitric acid are mixed at a volume ratio of 2.5:1), ultrasonically dispersed at a frequency of 35kHz for 2.8h, centrifuged, and the lower precipitate is washed with deionized water until the washing solution is neutral. The precipitate is then placed in a vacuum drying oven and dried at 95℃ for 11h. After grinding, acidified carbon nanotubes are obtained. Nanotubes were placed in 1000 mL of titanium precursor mixture and ultrasonically dispersed at 35 kHz for 2.5 h. A mixed solution of nickel nitrate and cobalt nitrate was added dropwise while stirring (the sum of the masses of nickel nitrate and cobalt nitrate in the mixed solution of nickel nitrate and cobalt nitrate was 3.8% of the mass of the acidified carbon nanotubes). Stirring was continued for 1.5 h, then stirring was stopped, and the mixture was aged for 2.5 h. The mixture was then placed in a vacuum drying oven and dried at 85 °C for 14 h. The mixture was ground into powder and then calcined in a muffle furnace at a heating rate of 18 °C / min to 580 °C for 3.5 h. After cooling, modified carbon nanotubes were obtained.

[0079] Comparative Example 1

[0080] In this comparative example, the aluminum-based hydrogen production material and its preparation process are similar to those in Example 4. The difference between this comparative example and Example 4 is that in the preparation process of the composite activator in this comparative example, an equal amount of antimony trioxide is used instead of vanadium pentoxide.

[0081] Comparative Example 2

[0082] In this comparative example, the aluminum-based hydrogen production material and its preparation process are similar to those in Example 4. The difference between this comparative example and Example 4 is that carbon nanotubes are used instead of modified carbon nanotubes in the preparation process of the composite activator in this comparative example.

[0083] Comparative Example 3

[0084] In this comparative example, the aluminum-based hydrogen production material and its preparation process are similar to those in Example 4. The difference between this comparative example and Example 4 is that the mass ratio of antimony trioxide, vanadium pentoxide and modified carbon nanotubes in the composite activator of this comparative example is 0.65:0.35:1.

[0085] Comparative Example 4

[0086] In this comparative example, the aluminum-based hydrogen production material and its preparation process are similar to those in Example 4. The difference between this comparative example and Example 4 is as follows: The modified carbon nanotubes in this comparative example are prepared as follows: Carbon nanotubes are placed in 1000 mL of titanium precursor mixture and ultrasonically dispersed at a frequency of 35 kHz for 2.5 h. A mixed solution of nickel nitrate and cobalt nitrate is added dropwise while stirring (the sum of the masses of nickel nitrate and cobalt nitrate in the mixed solution is 4% of the mass of the acidified carbon nanotubes). Stirring is continued for 1.5 h, then stirring is stopped, and the mixture is aged for 2.5 h. The mixture is then placed in a vacuum drying oven and dried at 85 °C for 14 h. After grinding into powder, the mixture is placed in a muffle furnace and calcined at 580 °C for 3.5 h at a heating rate of 18 °C / min. After cooling, the modified carbon nanotubes are obtained. That is, the carbon nanotubes in this comparative example are not acidified.

[0087] Comparative Example 5

[0088] The aluminum-based hydrogen production material and its preparation process described in this comparative example are similar to those in Example 4. The difference between this comparative example and Example 4 is that an equal amount of nickel nitrate is used instead of cobalt nitrate in the preparation method of the modified carbon nanotubes in this comparative example.

[0089] Test example

[0090] Test samples: Aluminum-based hydrogen production materials prepared in Examples 1-5 and Comparative Examples 1-5;

[0091] Experimental Method: A 5g sample was placed in 100mL of water from an argon-filled glove box to conduct a hydrolysis hydrogen production experiment. The initial reaction temperature was controlled at 25℃. The generated gas passed through a condenser and then into a filter tube filled with calcium chloride and blue silica gel desiccant. The cooled and dried varnish was then collected in a container filled with water, and the displaced water was discharged into a beaker. During the experiment, the hydrogen production rate was measured using a hydrogen flow meter, and the real-time hydrogen production rate was displayed directly on a computer via software.

[0092] The test results are shown in Table 1 and Figure 1 , Figure 2.

[0093] Table 1 Performance Test Results

[0094]

[0095] From Table 1 and Figure 1 , Figure 2 It can be seen that, at room temperature, the hydrogen production of 5g of the aluminum-based hydrogen production material prepared by this invention is 3.259-3.854L, and the maximum hydrogen production rate is 1.623-2.010L / min. This indicates that the aluminum-based hydrogen production material provided by this invention has a high hydrogen production capacity and a high hydrogen production rate.

[0096] From Table 1 and Figure 3 , Figure 4 It can be seen that, compared with Example 4, in the preparation process of the composite activator in Comparative Example 1, antimony trioxide was used instead of vanadium pentoxide in equal amounts, but the hydrogen production rate and maximum hydrogen production rate of the aluminum-based hydrogen production material were reduced. This indicates that antimony ions and vanadium oxide ions in the composite activator played a synergistic role. In the preparation process of the composite activator in Comparative Example 2, carbon nanotubes were used instead of modified carbon nanotubes, but the hydrogen production of the aluminum-based hydrogen production material was slightly reduced, and the maximum hydrogen production rate was reduced. This indicates that the modification of carbon nanotubes in this invention can improve the electron transfer rate of carbon nanotubes, promote the reaction between aluminum and water, and effectively improve the hydrogen production rate. In Comparative Example 3, the mass ratio of antimony trioxide, vanadium pentoxide, and modified carbon nanotubes in the composite activator was changed, but the hydrogen production and maximum hydrogen production rate of the aluminum-based hydrogen production material were reduced to varying degrees. This indicates that the modification of carbon nanotubes in this invention can improve the electron transfer rate of carbon nanotubes, promote the reaction between aluminum and water, and effectively improve the hydrogen production rate. In the invented composite activator, the mass ratio of antimony trioxide, vanadium pentoxide, and modified carbon nanotubes has been optimized. Increasing the amount of antimony trioxide and vanadium pentoxide will block the pore structure of carbon nanotubes, affecting the adsorption and diffusion of water molecules by carbon nanotubes, thus affecting the hydrogen production efficiency and hydrogen production rate. In Comparative Example 4, no acidification treatment was performed on the carbon nanotubes, but the hydrogen production rate and maximum hydrogen production rate of the prepared aluminum-based hydrogen production material decreased. This indicates that the acidification treatment of carbon nanotubes can enhance their electrostatic attraction with metal ions and improve the electron transfer efficiency during the reaction between aluminum and water. In the preparation method of modified carbon nanotubes in Comparative Example 5, an equal amount of nickel nitrate was used instead of cobalt nitrate, but the hydrogen production rate and maximum hydrogen production rate of the prepared aluminum-based hydrogen production material decreased. This indicates that nickel nitrate and cobalt nitrate have a synergistic effect, effectively improving the hydrogen production rate and hydrogen production rate of the aluminum-based hydrogen production material.

[0097] In addition, the present invention also conducted XRD tests on the composite activator prepared in Example 4, and the test results are shown in [Figure 4]. Figure 5 .Depend on Figure 5It can be seen that a peak of antimony sulfate appeared at 25.4°, an overlapping peak of vanadium sulfate and carbon nanotubes appeared at 27.0°, and a weak peak of carbon nanotubes appeared at 44.0°; peaks of nickel ions appeared at 45.08°, 51.05°, and 76.76°, and peaks of cobalt ions appeared at 52.25° and 76.0°. This indicates that the composite activator prepared by this invention contains antimony ions, vanadium oxide ions, carbon nanotubes, nickel ions, and cobalt ions, and the preparation of the composite activator was successful.

[0098] The above embodiments are merely illustrative of the present invention and are not intended to limit the invention. Those skilled in the art should not modify the above embodiments without departing from the spirit and scope of the present invention. All equivalent modifications or alterations made by those skilled in the art without departing from the technical concept of the present invention are still within the protection scope of the present invention.

Claims

1. An aluminum-based hydrogen production material, comprising the following components in parts by weight: The mixture comprises 60-80 parts aluminum powder, 10-15 parts composite activator, 3-6 parts activated metal, and 5-8 parts salt. The composite activator is a composite material prepared from antimony trioxide, vanadium pentoxide, and modified carbon nanotubes. The modified carbon nanotubes are prepared by: placing carbon nanotubes in an acid solution, ultrasonically dispersing, centrifuging, washing, drying, and grinding to obtain acidified carbon nanotubes; placing the acidified carbon nanotubes in a titanium precursor mixture, ultrasonically dispersing, adding a mixed solution of nickel nitrate and cobalt nitrate dropwise while stirring, continuing to stir for 1.2-1.6 hours, stopping stirring, aging for 2-3 hours, drying, grinding, and calcining at a rate of 15-20℃ / min to 500-600℃ for 3-4 hours to obtain modified carbon nanotubes. The total mass of nickel nitrate and cobalt nitrate in the mixed solution is 3%-5% of the mass of the acidified carbon nanotubes. The mixed solution is prepared by mixing anhydrous ethanol and deionized water at a volume ratio of 5:1, adding nickel nitrate and cobalt nitrate while stirring, adjusting the pH of the solution to 2-3, and continuing to stir for 3-3.5 hours to obtain the mixed solution of nickel nitrate and cobalt nitrate. The mass ratio of nickel nitrate to cobalt nitrate is 3-5:7-9.

2. The aluminum-based hydrogen production material according to claim 1, characterized in that, The preparation method of the composite activator is as follows: antimony trioxide and vanadium pentoxide are added to sulfuric acid solution, stirred and dissolved, modified carbon nanotubes are added, stirred and sonicated, potassium chloride solution is added, and stirring is continued for 4-4.5 hours. Solid-liquid separation is performed, followed by washing and drying to obtain the composite activator.

3. The aluminum-based hydrogen production material according to claim 2, characterized in that, The mass ratio of antimony trioxide, vanadium pentoxide, and modified carbon nanotubes is 0.23-0.36:0.09-0.17:

1.

4. The aluminum-based hydrogen production material according to claim 2, characterized in that, The sulfuric acid solution has a mass percentage of 30%-40%; the potassium chloride solution has a concentration of 1-1.5 mol / L; the ultrasonic frequency of the stirring and ultrasonication is 45-60 kHz, and the stirring and ultrasonication time is 6-8 h.

5. The aluminum-based hydrogen production material according to claim 1, characterized in that, The acid solution is a mixture of concentrated sulfuric acid and concentrated nitric acid, with a volume ratio of 2-3:1; the ultrasonic dispersion is performed at a frequency of 30-40 kHz for 2-3 hours.

6. The aluminum-based hydrogen production material according to claim 1, characterized in that, The preparation method of the titanium precursor mixture is as follows: Anhydrous ethanol, deionized water and concentrated nitric acid were mixed and then added to tetrabutyl titanate. The mixture was stirred for 1.0-1.5 h to obtain a titanium precursor mixture. The volume ratio of anhydrous ethanol, deionized water, concentrated nitric acid, and tetrabutyl titanate is 70-73:7-10:3-6:25:

30.

7. The aluminum-based hydrogen production material according to claim 1, characterized in that, The activated metal is one of magnesium, zinc, manganese and chromium; the salt is one of sodium chloride, potassium chloride and magnesium chloride.

8. The preparation process of the aluminum-based hydrogen production material according to any one of claims 1-7, characterized in that, Specifically, aluminum powder, composite activator, activated metal and salt are mixed evenly and ball-milled under the protection of inert gas. The ball-to-material ratio is 10-20:1, the ball milling speed is 300-400 rpm, and the ball milling time is 20-24 hours.

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