Hydrolysis hydrogen production aluminum alloy and preparation method thereof

Abstract

The invention discloses a hydrolysis hydrogen production aluminum alloy and a preparation method thereof, and belongs to the technical field of hydrolysis hydrogen production. The hydrolysis hydrogen production aluminum alloy comprises the following raw materials in parts by weight: 80-98 parts of Al, 5-10 parts of Ga, 1-10 parts of In, 0.1-5 parts of Sn and 0.1-5 parts of Zn. The preparation method specifically comprises the following steps: (1) weighing the raw materials according to the parts by weight of the hydrolysis hydrogen production aluminum alloy; and (2) mixing the raw materials, carrying out mechanical ball milling, and carrying out 3D printing. According to the method, the aluminum alloy powder is mixed through a mechanical ball milling method, then the aluminum alloy powder is made into a honeycomb or other complex porous structure through the 3D printing technology so as to increase the specific surface area, and then the reaction rate of the aluminum alloy and water and the hydrogen production efficiency are improved. According to the hydrolysis hydrogen production aluminum alloy, the formation of an inert oxidation film can be well inhibited, the hydrogen production rate of unit mass alloy can be greatly improved through reaction at the normal temperature, and meanwhile a hydrogen supply device integrating start-stop controllability and product recovery is designed according to the aluminum water reaction characteristics.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology by hydrolysis, and more specifically to a hydrogen production aluminum alloy by hydrolysis and its preparation method. Background Technology

[0002] Hydrogen is the most promising new energy source. It has a very high calorific value; excluding nuclear fuel, it has the highest calorific value among all fossil fuels, chemical fuels, and biofuels, and is three times that of gasoline. Compared to the three traditional energy sources, hydrogen has advantages such as being renewable and pollution-free.

[0003] Aluminum is abundant on Earth, widely available, inexpensive, and has a low density. The hydrolysis of metallic aluminum produces a high yield and rate of hydrogen, and the reaction does not generate harmful carbon and nitrogen-containing substances, resulting in environmentally friendly products.

[0004] However, aluminum alloys currently used for hydrogen production by water electrolysis have disadvantages such as small specific surface area, low reaction rate, low hydrogen production rate, and high requirements for water electrolysis hydrogen generators.

[0005] Therefore, how to improve the reaction rate and conversion rate of hydrolyzed aluminum alloys for hydrogen production is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a hydrolytic hydrogen-producing aluminum alloy and its preparation method, so as to overcome the shortcomings of the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A hydrolytic hydrogen-producing aluminum alloy comprises the following raw materials in parts by weight: 80-98 parts Al (aluminum), 5-10 parts Ga (gallium), 1-10 parts In (indium), 0.1-5 parts Sn (tin), and 0.1-5 parts Zn (zinc).

[0008] This invention enhances the activity of aluminum alloys by adding low-melting-point metal elements. The mechanism involves disrupting the integrity of the oxide film on the aluminum surface. Specifically, elemental Ga affects the tension of the inert oxide film on the aluminum surface, providing a channel for hydrogen escape and reducing the continuity and density of the oxide film. When the hydrogen production rate or amount reaches a certain critical value, the aluminum oxide cannot completely cover the Al surface, exposing fresh aluminum, allowing the reaction to continue. A potential difference exists between the alloy phase, compounds, and other second phases and the Al matrix, forming a microscopic galvanic cell that accelerates the hydrolysis of the aluminum alloy to produce hydrogen. Simultaneously, the aluminum-water reaction is exothermic, and the heat generated further accelerates the reaction.

[0009] Low-melting-point metallic elements (Ga, In, Sn, Zn, etc.) exist in aluminum in two forms: one is as an Al(X) solid solution formed with aluminum during cooling, where X represents a low-melting-point metal; the other is as a segregated phase existing at the grain boundaries of Al. During the alloying reaction, the solid solution in the aluminum alloy plays an activating role. The activation mechanism can be understood as follows: during the reaction, cathode ions other than Al undergo an electrochemical exchange reaction with Al and are deposited on the Al surface. Simultaneously, this reaction locally disrupts the oxide film on the Al alloy surface, causing a negative shift in the electrode potential of Al.

[0010] Furthermore, the aforementioned hydrolysis-based hydrogen-producing aluminum alloy comprises the following raw materials in parts by weight: 80-90 parts Al, 5-10 parts Ga, 1-5 parts In, 0.1-4 parts Sn, and 0.1-4 parts Zn.

[0011] Furthermore, the aforementioned hydrolytic hydrogen-producing aluminum alloy comprises the following raw materials in parts by weight: Al 83-88 parts, Ga 5.5-9 parts, In 1-4 parts, Sn 0.1-3 parts, and Zn 0.1-3 parts.

[0012] In this invention, Al is Al powder with a purity of not less than 99% and a particle size of 30-100 μm, preferably 30-50 μm. After activation, Al reacts with water to generate hydrogen gas.

[0013] In this invention, Ga is Ga powder with a purity of not less than 99% and a particle size of 30-100 μm, preferably 30-50 μm. During ball milling, Ga dissolves Al, preventing the formation of an oxide film on the Al surface in the Ga and improving the hydrogen production performance of the aluminum alloy through hydrolysis.

[0014] In this invention, In is In powder with a purity of not less than 99% and a particle size of 30-100 μm, preferably 30-50 μm. During ball milling, In disrupts the dense oxide film on the Al surface, thereby increasing the hydrolytic reactivity of the aluminum alloy.

[0015] In this invention, Sn is Sn powder with a purity of not less than 99% and a particle size of 30-100 μm, preferably 30-50 μm. During ball milling, Sn disrupts the dense oxide film on the Al surface, thereby increasing the hydrolytic reactivity of the aluminum alloy.

[0016] In this invention, Zn is Zn powder with a purity of not less than 99% and a particle size of 30-100 μm, preferably 30-50 μm. During ball milling, Zn disrupts the dense oxide film on the Al surface, thereby increasing the hydrolytic reactivity of the aluminum alloy.

[0017] Furthermore, the aforementioned hydrolytic hydrogen-producing aluminum alloy also includes the following raw materials in parts by weight: 3-5 parts of Hg (mercury), 3-5 parts of Bi (bismuth), 0.1-1 parts of SnCl2 (stannous chloride), and 0.1-1 parts of Bi2O3 (bismuth trioxide).

[0018] The further beneficial effect of adopting the above is that the micro-corrosion cell mechanism is one of the main factors affecting the reaction of aluminum and aluminum alloys with solution, and the specific process is shown in equations (1) and (2) below: Al + 2H₂O → AlOOH + 3H₂O + Equation (1); 3H + +M→3 / 2H2+X (X: Hg, Bi, Sn, In, etc.) Equation (2).

[0019] In this reaction, gibbsite is deposited on an electrode with aluminum as the anode, while hydrogen is deposited on an electrode with a low-melting-point metal as the cathode. The addition of certain low-melting-point alloys shifts the electrode potential of the aluminum anode negatively, thereby increasing the activity of the aluminum. Simultaneously, the introduction of certain ions into the reaction solution can significantly promote the reaction. For example, chloride ions can react not only with the oxide film on the aluminum surface but also with the anode aluminum, accelerating the reaction rate while sacrificing hydrogen production efficiency.

[0020] In this invention, Hg is in liquid form with a purity of 99.9%.

[0021] In this invention, the Bi purity is 99.9%, and the particle size is 10-50 μm, preferably 30 μm. Bi particles can be embedded and uniformly dispersed within Al particles. Furthermore, cracks appear on the particle surface, which facilitates greater exposure of the Al particles for water contact. During ball milling, the oxide film on the Al particle surface is partially destroyed by mechanical force. Simultaneously, the added Bi particles can adhere to the surface of the Al particles.

[0022] In this invention, SnCl2 inhibits the agglomeration of composites during ball milling, causing the alloy material particles to gradually become smaller. At the same time, it generates a large number of fresh surfaces and defects in the alloy material, increasing the contact area between the alloy material and water, improving the hydrolytic activity of the alloy material, and promoting the hydrolytic hydrogen production reaction of the alloy material.

[0023] In this invention, the purity of Bi2O3 is 99.9%, and the particle size is 5-10 μm, preferably 8 μm. The increase in Bi2O3 content leads to an increase in the total amount of embedded material. As the quantity increases, the reduced continuity of the aluminum oxide film on the surface due to the embedded material is the reason for the increased hydrogen production.

[0024] A method for preparing a hydrogen-producing aluminum alloy by hydrolysis specifically includes the following steps: (1) Weigh each raw material according to the above-mentioned weight proportions for hydrolysis to produce hydrogen aluminum alloy; (2) Mix the raw materials, mechanically ball mill, and 3D print to obtain hydrolytic hydrogen-producing aluminum alloy.

[0025] This invention employs mechanical ball milling. Adding low-melting-point metals during this process leads to embrittlement of the aluminum powder, formation of aluminum cracks, and weakening of the alumina film. Clearly, more cracks are generated, and the alumina film is more severely damaged. Liquid low-melting-point metals cover and protect the surface of the new aluminum, preventing the formation of an oxide layer. Simultaneously, during the aluminum-water reaction, the contact area between the second phase and water increases. Therefore, aluminum reacts well with water at room temperature. Furthermore, this invention uses a 3D-printed porous aluminum alloy to produce hydrogen, offering advantages such as zero pollution and renewability.

[0026] Furthermore, in step (2) above, both mechanical ball milling and 3D printing are performed under the protection of an inert gas. Simultaneously, to prevent oxidation of the surface of the hydrolyzed hydrogen-producing aluminum alloy obtained after ball milling, vacuum or inert gas protection is applied after ball milling. Even further, the inert gas is nitrogen.

[0027] The further beneficial effect of adopting the above is to prevent metal oxidation.

[0028] Furthermore, in step (2) above, the equipment for mechanical ball milling is a planetary ball mill with a spindle speed of 100-400 r / min, preferably 200-400 r / min, and more preferably 300-400 r / min.

[0029] Furthermore, in step (2) above, the ball-to-material ratio of the mechanical ball mill is (15-25):1, preferably (18-22):1, and most preferably 20:1; the mechanical ball milling time is 1-60h, preferably 5-15h, more preferably 8-15h, and most preferably 10-15h.

[0030] Furthermore, in step (2) above, the metal powder particles are mechanically ball-milled to a particle size of 30-100μm, preferably 30-50μm; the purity mass fraction of the metal powder particles is 99.9%.

[0031] The present invention also claims protection for the application of the above-described hydrolysis hydrogen production aluminum alloy or the hydrolysis hydrogen production aluminum alloy prepared by the above-described preparation method in hydrolysis hydrogen production.

[0032] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] This invention first uses mechanical ball milling to mix aluminum alloy powder, and then uses 3D printing technology to make the aluminum alloy powder into a honeycomb or other complex porous structure to increase the specific surface area, thereby increasing the reaction rate of aluminum alloy with water and hydrogen production efficiency.

[0034] The hydrolytic hydrogen-producing aluminum alloy of this invention can not only effectively inhibit the formation of inert oxide films, but also significantly improve the hydrogen production rate per unit mass of alloy at room temperature, showing good application prospects.

[0035] The hydrolytic hydrogen-producing aluminum alloy of this invention can directly react with water to produce hydrogen, effectively avoiding the use of strong alkaline solutions, and has low requirements for the hydrolytic hydrogen generator, thus posing no safety hazards to users.

[0036] The hydrolytic hydrogen-producing aluminum alloy of this invention has a significantly increased surface area in contact with water per unit mass when reacting with water, thereby effectively increasing the reaction rate of the alloy with water and the hydrogen production rate. It is an efficient and convenient way to produce hydrogen.

[0037] The hydrogen-producing aluminum alloy of this invention can react with water at room temperature to produce hydrogen, with a hydrogen production rate of more than 94%.

[0038] The mechanical ball milling method used in this invention can suppress the formation of oxide film, thereby allowing the hydrolysis reaction to proceed continuously.

[0039] This invention designs a hydrogen supply device that integrates start-stop control and product recovery based on the reaction characteristics of aluminum water. Attached Figure Description

[0040] Figure 1 A process flow diagram for the preparation method of hydrogen-producing aluminum alloy by hydrolysis; Figure 2 A schematic diagram of the structure of the water electrolysis hydrogen production system and a process flow diagram of the water electrolysis hydrogen production operation; Figure 3 The hydrogen production of the aluminum alloys used in Examples 1-3 is shown. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Example 1 Hydrogen-producing aluminum alloy comprises the following raw materials by weight: Al 90g, Ga 7g, In 2g, Sn 1g, Zn 1g, Hg 3g, Bi 3g, SnCl2 0.1g, and Bi2O3 0.1g.

[0043] The above-mentioned method for preparing hydrogen-producing aluminum alloys by hydrolysis, such as... Figure 1 As shown, the specific steps include: (1) Weigh each raw material according to the above weight, mix each raw material evenly and put it into a planetary ball mill filled with nitrogen for ball milling. The ball-to-material ratio is 20:1, the spindle speed is 360r / min, and the ball milling time is 12h. (2) After ball milling, the obtained ball milling product is placed in a 3D printer filled with nitrogen, and the powder is made into porous coal balls according to the drawings. Finally, it is placed in a sealed container filled with nitrogen to obtain hydrolyzed hydrogen-producing aluminum alloy.

[0044] Example 2 Hydrogen-producing aluminum alloy comprises the following raw materials by weight: Al 85g, Ga 9.3g, In 3.75g, Sn 1.95g, Zn 2g, Hg 4g, Bi 4g, SnCl2 0.5g, and Bi2O3 0.5g.

[0045] The above-mentioned method for preparing hydrogen-producing aluminum alloys by hydrolysis, such as... Figure 1 As shown, the specific steps include: (1) Weigh each raw material according to the above weight, mix each raw material evenly and put it into a planetary ball mill filled with nitrogen for ball milling. The ball-to-material ratio is 20:1, the spindle speed is 360r / min, and the ball milling time is 12h. (2) After ball milling, the obtained ball milling product is placed in a 3D printer filled with nitrogen, and the powder is made into porous coal balls according to the drawings. Finally, it is placed in a sealed container filled with nitrogen to obtain hydrolyzed hydrogen-producing aluminum alloy.

[0046] Example 3 Hydrogen-producing aluminum alloy by hydrolysis comprises the following raw materials by weight: Al 85g, Ga 9g, In 3.75g, Sn 1.5g, Zn 0.75g, Hg 5g, Bi 5g, SnCl2 1g, and Bi2O3 1g.

[0047] The above-mentioned method for preparing hydrogen-producing aluminum alloys by hydrolysis, such as... Figure 1 As shown, the specific steps include: (1) Weigh each raw material according to the above weight, mix each raw material evenly and put it into a planetary ball mill filled with nitrogen for ball milling. The ball-to-material ratio is 20:1, the spindle speed is 360r / min, and the ball milling time is 12h. (2) After ball milling, the obtained ball milling product is placed in a 3D printer filled with nitrogen, and the powder is made into porous coal balls according to the drawings. Finally, it is placed in a sealed container filled with nitrogen to obtain hydrolyzed hydrogen-producing aluminum alloy.

[0048] Performance testing Take the hydrolytic hydrogen-producing aluminum alloys obtained in Examples 1-3, and respectively, and arrange them according to the following... Figure 2The water electrolysis hydrogen production system shown reacts with water at room temperature, and the hydrogen production is measured. The hydrogen production rate is calculated according to the conventional method in the art: "hydrogen production rate = hydrogen production per unit mass of composition / 1244".

[0049] The results are shown in Table 1 and Figure 3 As shown.

[0050] Table 1. Hydrogen production rate and yield of aluminum alloys produced by hydrolysis in Examples 1-3 Hydrolysis to produce hydrogen aluminum alloy Hydrogen production (mL / g) Hydrogen production rate (%) Example 1 1180 94.9 Example 2 1197 96.2 Example 3 1210 97.3 From Table 1 and Figure 3 It can be seen that the hydrogen production effect of the hydrolyzed hydrogen-producing aluminum alloys in Examples 1-3 meets the requirements of portable hydrogen sources and vehicle-mounted hydrogen sources.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydrolytic hydrogen-producing aluminum alloy, characterized in that, The raw materials include the following parts by weight: Al 80-98 parts, Ga 5-10 parts, In 1-10 parts, Sn 0.1-5 parts and Zn 0.1-5 parts.

2. The hydrolytic hydrogen-producing aluminum alloy according to claim 1, characterized in that, The raw materials include the following parts by weight: Al 80-90 parts, Ga 5-10 parts, In 1-5 parts, Sn 0.1-4 parts and Zn 0.1-4 parts.

3. The hydrolytic hydrogen-producing aluminum alloy according to claim 1 or 2, characterized in that, It also includes the following raw materials in parts by weight: 3-5 parts Hg, 3-5 parts Bi, 0.1-1 parts SnCl2 and 0.1-1 parts Bi2O3.

4. A method for preparing a hydrolytic hydrogen-producing aluminum alloy, characterized in that, Specifically, the following steps are included: (1) Weigh each raw material according to the weight proportions of the hydrolytic hydrogen-producing aluminum alloy according to any one of claims 1-3; (2) Mix the raw materials, mechanically ball mill, and 3D print to obtain the hydrolytic hydrogen-producing aluminum alloy.

5. The method for preparing a hydrolytic hydrogen-producing aluminum alloy according to claim 4, characterized in that, In step (2), both the mechanical ball milling and 3D printing are carried out under the protection of an inert gas.

6. The method for preparing a hydrolytic hydrogen-producing aluminum alloy according to claim 5, characterized in that, The inert gas is nitrogen.

7. The method for preparing a hydrolytic hydrogen-producing aluminum alloy according to claim 4, characterized in that, In step (2), the equipment for mechanical ball milling is a planetary ball mill with a spindle speed of 100-400 r / min.

8. The method for preparing a hydrolytic hydrogen-producing aluminum alloy according to claim 4, characterized in that, In step (2), the ball-to-material ratio of the mechanical ball mill is (15-25):1, and the ball milling time is 1-60h.

9. The method for preparing a hydrolytic hydrogen-producing aluminum alloy according to claim 4, characterized in that, In step (2), the mechanical ball milling process is carried out until the particle size of the metal powder particles is 30-100 μm.

10. The application of a hydrolytic hydrogen production aluminum alloy as described in any one of claims 1-3 or a hydrolytic hydrogen production aluminum alloy prepared by the preparation method as described in any one of claims 4-9 in hydrolytic hydrogen production.

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