Method for preparing hydrogen through cooperation of dendritic copper powder preparation and methanol reforming

Abstract

The invention discloses a method for preparing dendritic copper powder and cooperating with methanol reforming for hydrogen production, which comprises the following steps: in a single reaction system, dissolving a copper source and an alkali source in methanol, aging, transferring into a reaction kettle, reacting for 1-6 hours at 250-300 DEG C, and synchronously realizing in-situ preparation of the dendritic copper powder and methanol liquid phase reforming for hydrogen production through a one-step method. According to the method, methanol is used as a solvent, a reducing agent and a reactant at the same time, two independent processes are efficiently coupled, and the process is remarkably simplified; and after the reaction, dendritic copper powder with a three-dimensional branched structure and a gas product mainly containing hydrogen can be obtained at the same time.

Description

Technical Field

[0001] This invention relates to a method for preparing dendritic copper powder and co-processing methanol to produce hydrogen, belonging to the field of copper powder and hydrogen energy preparation technology. Background Technology

[0002] Dendritic copper powder, due to its unique branched structure, possesses high specific surface area, excellent conductivity, and abundant active sites, making it widely used in high-end technology fields such as electronic and conductive materials and electromagnetic shielding. Commonly used methods for preparing dendritic copper powder are chemical reduction and electrochemical deposition, but both require precise control of reaction process conditions. Methanol liquid-phase reforming for hydrogen production is an important method, and copper-based catalysts are commonly used in its production.

[0003] In existing technologies, the preparation of dendritic copper powder (such as chemical reduction and electrochemical deposition) and methanol reforming for hydrogen production (usually using pre-prepared copper-based catalysts) are two independent processes. The former is complex, while the latter requires additional catalyst preparation, shaping, and activation steps, resulting in long processes and high energy consumption. Furthermore, although recent patents (such as CN117599786A) involve the preparation of high-performance copper-based catalysts, they still employ complex processes involving multi-step calcination and impregnation, and the catalyst must be in a separate, independent reaction apparatus to catalyze methanol-to-hydrogen production, failing to achieve process coupling and simplification. Therefore, developing a method for simultaneously and easily preparing dendritic copper powder and producing hydrogen in the same reaction system is of great significance. Summary of the Invention

[0004] This invention aims to overcome the shortcomings of the prior art and provide a method for the preparation of dendritic copper powder and the synergistic methanol reforming for hydrogen production. The core of this method lies in coupling the preparation of dendritic copper powder and the methanol reforming for hydrogen production within a single methanol reaction system, achieving simultaneous results in a one-step process, thereby greatly simplifying the process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing dendritic copper powder and simultaneously producing hydrogen via methanol reforming is disclosed. This method, within a single reaction system, simultaneously achieves in-situ preparation of dendritic copper powder and methanol liquid-phase reforming for hydrogen production via methanol thermal reduction. The method includes the following steps: (1) Dissolve the copper source in methanol to obtain a first solution; dissolve the alkali source in methanol to obtain a second solution; under stirring conditions, add the second solution to the first solution, continue to add additional alkali source, stir and carry out aging treatment to obtain a mixture; (2) The mixture obtained in step (1) is transferred to a reaction vessel and reacted at a temperature of 250°C to 300°C. After the reaction is completed, the mixture is cooled and the generated gas is collected. The liquid and solid mixture in the reaction vessel is separated, washed and dried to obtain dendritic copper powder.

[0006] Further preferably, the copper source is copper sulfate pentahydrate; the alkali source is sodium hydroxide.

[0007] Further preferred, in step (1), the total amount of the alkali source, calculated as sodium hydroxide, has a mass ratio of 1.3 to 2.5:1 with the copper source, calculated as copper sulfate pentahydrate.

[0008] Further optimization is that in step (2), the reaction time is 1 to 6 hours.

[0009] More preferably, the drying is vacuum drying, the drying temperature is 40℃ to 80℃, and the vacuum drying time is 24-48h.

[0010] Further preferred, in step (1), the aging treatment time is 0.5 hours to 2 hours.

[0011] Further preferred, in step (2), the dendritic copper powder has a three-dimensional branched structure.

[0012] Technical effects of the present invention: This invention couples the preparation of dendritic copper powder and the methanol reforming for hydrogen production into a single methanol reaction system, achieving simultaneous one-step completion. Methanol serves as both a solvent for dissolving the copper and alkali sources, a reducing agent for reducing Cu²⁺, and a reactant for reforming to generate hydrogen. The reduction of copper ions and the methanol reforming reaction mutually promote each other, improving the overall reaction efficiency. This not only eliminates complex steps such as the separation, transfer, catalyst shaping, and activation of intermediate products, but also significantly reduces equipment investment and operating costs, making the entire process simpler, more efficient, and easier to scale up.

[0013] The dendritic copper powder obtained by this invention has a unique three-dimensional branching structure. The resulting dendritic copper powder can be directly used as a high-performance conductive material, catalyst precursor, etc. in multiple high-end fields without complicated processing, which significantly improves the economic efficiency of the process. Attached Figure Description

[0014] Figure 1 This is a scanning electron microscope image of copper powder with a dendritic structure according to the present invention.

[0015] Figure 2 This is a gas chromatogram of the gas collected after the dendritic copper powder preparation reaction of the present invention.

[0016] Figure 3 Scanning electron microscope (SEM) images of the copper powder prepared in the comparative examples. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to these embodiments. Example 1

[0018] (1) Dissolve copper sulfate pentahydrate in 200 mL of methanol until saturated to obtain copper sulfate methanol solution; dissolve 10 g of sodium hydroxide in 100 mL of methanol to obtain sodium hydroxide methanol solution; add sodium hydroxide methanol solution to copper sulfate methanol solution under stirring conditions, and continue to add sodium hydroxide (so that the total amount of sodium hydroxide used is 1.3 times the mass ratio of copper sulfate pentahydrate), stir and age for 1 h to obtain a mixture (containing liquid and solid); (2) The mixture obtained above was transferred to a 500 mL reactor and reacted at 250 °C for 6 h. After cooling to room temperature, the generated gas was collected (it was found to be mainly hydrogen). Figure 2 (This is a gas chromatogram of the gas collected after the reaction for preparing dendritic copper powder). (3) The mixture of liquid and solid in the reactor was filtered through a membrane. The solid obtained by filtration was washed with distilled water, and then the washed solid was vacuum dried at 40°C for 48 h to obtain copper powder. The copper powder was characterized by scanning electron microscopy (SEM), as follows: Figure 1 As shown, it exhibits a typical three-dimensional branched structure, and its branch length is measured to be in the range of 10-30 micrometers, hence it is called dendritic copper powder. Example 2

[0019] Copper sulfate pentahydrate was dissolved in 200 mL of methanol until saturated to obtain a copper sulfate methanol solution; 10 g of sodium hydroxide was dissolved in 100 mL of methanol to obtain a sodium hydroxide methanol solution. Under stirring conditions, the sodium hydroxide methanol solution was added to the copper sulfate methanol solution, and sodium hydroxide was added again (so that the total amount of sodium hydroxide to the mass ratio of copper sulfate pentahydrate was 2.5). The mixture was stirred and aged for 1 hour to obtain a mixture. (2) Transfer the mixture obtained above to a 500 mL reactor, react at 300 °C for 1 h, cool to room temperature, and collect the gas (mainly hydrogen). (3) The mixture of liquid and solid in the reactor is filtered through a membrane, and the solid obtained by filtration is washed with distilled water. The washed solid is then vacuum dried at 40°C for 48 hours to obtain dendritic copper powder. Example 3

[0020] Copper sulfate pentahydrate was dissolved in 200 mL of methanol until saturated to obtain a copper sulfate methanol solution; 10 g of sodium hydroxide was dissolved in 100 mL of methanol to obtain a sodium hydroxide methanol solution. Under stirring conditions, the sodium hydroxide methanol solution was added to the copper sulfate methanol solution, and sodium hydroxide was added again (so that the total amount of sodium hydroxide to the mass ratio of copper sulfate pentahydrate was 2.3). The mixture was stirred and aged for 1 hour to obtain a mixture. (2) Transfer the mixture obtained above to a 500 mL reactor, react at 290 °C for 2 h, cool to room temperature, and collect the gas (mainly hydrogen). (3) The mixture of liquid and solid in the reactor is filtered through a membrane, and the solid obtained by filtration is washed with distilled water. The washed solid is then vacuum dried at 40°C for 48 hours to obtain dendritic copper powder. Example 4

[0021] Copper sulfate pentahydrate was dissolved in 200 mL of methanol until saturated to obtain a copper sulfate methanol solution; 10 g of sodium hydroxide was dissolved in 100 mL of methanol to obtain a sodium hydroxide methanol solution. Under stirring conditions, the sodium hydroxide methanol solution was added to the copper sulfate methanol solution, and sodium hydroxide was added again (so that the total amount of sodium hydroxide to the mass ratio of copper sulfate pentahydrate was 2.0). The mixture was stirred and aged for 1 hour to obtain a mixture. (2) Transfer the mixture obtained above to a 500 mL reactor, react at 280 °C for 3 h, cool to room temperature, and collect the gas (mainly hydrogen). (3) The mixture of liquid and solid in the reactor is filtered through a membrane, and the solid obtained by filtration is washed with distilled water. The washed solid is then vacuum dried at 60°C for 32 hours to obtain dendritic copper powder. Example 5

[0022] Copper sulfate pentahydrate was dissolved in 200 mL of methanol until saturated to obtain a copper sulfate methanol solution; 10 g of sodium hydroxide was dissolved in 100 mL of methanol to obtain a sodium hydroxide methanol solution. Under stirring conditions, the sodium hydroxide methanol solution was added to the copper sulfate methanol solution, and sodium hydroxide was added again (so that the total amount of sodium hydroxide to the mass ratio of copper sulfate pentahydrate was 1.8). The mixture was stirred and aged for 1 hour to obtain a mixture. (2) Transfer the mixture obtained above to a 500 mL reactor and react at 270 °C for 3 h. Cool to room temperature and collect the gas (mainly hydrogen). (3) The mixture of liquid and solid in the reactor is filtered through a membrane, and the solid obtained by filtration is washed with distilled water. The washed solid is then vacuum dried at 60°C for 32 hours to obtain dendritic copper powder. Example 6

[0023] Copper sulfate pentahydrate was dissolved in 200 mL of methanol until saturated to obtain a copper sulfate methanol solution; 10 g of sodium hydroxide was dissolved in 100 mL of methanol to obtain a sodium hydroxide methanol solution. Under stirring conditions, the sodium hydroxide methanol solution was added to the copper sulfate methanol solution, and sodium hydroxide was added again (so that the total amount of sodium hydroxide to the mass ratio of copper sulfate pentahydrate was 1.7). The mixture was stirred and aged for 1 hour to obtain a mixture. (2) Transfer the mixture obtained above to a 500 mL reactor and react at 260 °C for 5 h. Cool to room temperature and collect the gas (mainly hydrogen). (3) The mixture of liquid and solid in the reactor is filtered through a membrane, and the solid obtained by filtration is washed with distilled water. The washed solid is then dried under vacuum at 80°C for 24 hours to obtain dendritic copper powder. Example 7

[0024] Dissolve 200 mL of copper sulfate pentahydrate in methanol until saturated to obtain a copper sulfate methanol solution; dissolve 10 g of sodium hydroxide in 100 mL of methanol to obtain a sodium hydroxide methanol solution. Under stirring conditions, add the sodium hydroxide methanol solution to the copper sulfate methanol solution, and continue to add sodium hydroxide (so that the total amount of sodium hydroxide used is 1.3 times the mass ratio of copper sulfate pentahydrate to sodium hydroxide), stir and age for 1 hour to obtain a mixture. (2) Transfer the mixture obtained above to a 500 mL reactor, react at 300 °C for 2 h, cool to room temperature, and collect the gas (mainly hydrogen). (3) The mixture of liquid and solid in the reactor is filtered through a membrane, and the solid obtained by filtration is washed with distilled water. The washed solid is then dried under vacuum at 80°C for 24 hours to obtain dendritic copper powder. Example 8

[0025] Copper sulfate pentahydrate was dissolved in 200 mL of methanol until saturated to obtain a copper sulfate methanol solution; 10 g of sodium hydroxide was dissolved in 100 mL of methanol to obtain a sodium hydroxide methanol solution. Under stirring conditions, the sodium hydroxide methanol solution was added to the copper sulfate methanol solution, and sodium hydroxide was added again (so that the total amount of sodium hydroxide to the mass ratio of copper sulfate pentahydrate was 2.5). The mixture was stirred and aged for 1 hour to obtain a mixture. (2) Transfer the mixture obtained above to a 500 mL reactor and react at 300 °C for 4 h. Cool to room temperature and collect the gas (mainly hydrogen). (3) The mixture of liquid and solid in the reactor is filtered through a membrane, and the solid obtained by filtration is washed with distilled water. The washed solid is then dried under vacuum at 80°C for 24 hours to obtain dendritic copper powder. Example 9

[0026] Copper sulfate pentahydrate was dissolved in 200 mL of methanol until saturated to obtain a copper sulfate methanol solution; 10 g of sodium hydroxide was dissolved in 100 mL of methanol to obtain a sodium hydroxide methanol solution. Under stirring conditions, the sodium hydroxide methanol solution was added to the copper sulfate methanol solution, and sodium hydroxide was added again (so that the total amount of sodium hydroxide to the mass ratio of copper sulfate pentahydrate was 2.0). The mixture was stirred and aged for 1 hour to obtain a mixture. (2) Transfer the mixture obtained above to a 500 mL reactor and react at 250 °C for 4 h. Cool to room temperature and collect the gas (mainly hydrogen). (3) The mixture of liquid and solid in the reactor is filtered through a membrane, and the solid obtained by filtration is washed with distilled water. The washed solid is then vacuum dried at 60°C for 32 hours to obtain dendritic copper powder.

[0027] Comparative Example: (1) Dissolve copper sulfate pentahydrate in 200 mL of methanol until saturated to obtain copper sulfate methanol solution; dissolve 10 g of sodium hydroxide in 100 mL of methanol to obtain sodium hydroxide methanol solution; add sodium hydroxide methanol solution to copper sulfate methanol solution under stirring conditions, and continue to add sodium hydroxide (so that the total amount of sodium hydroxide used is 1.3 times the mass ratio of copper sulfate pentahydrate), stir and age for 1 h to obtain a mixture (containing liquid and solid); (2) The mixture obtained above was transferred to a 500 mL reactor and reacted at 220 °C for 6 h. After cooling to room temperature, the generated gas was collected (which was found to be mainly hydrogen). (3) The mixture of liquid and solid in the reactor was filtered through a membrane. The solid obtained by filtration was washed with distilled water, and then the washed solid was vacuum dried at 40°C for 48 h to obtain copper powder. The copper powder was characterized by scanning electron microscopy (SEM), as follows: Figure 3 As shown, it exhibits copper powder in the form of particles of different sizes, rather than dendritic copper powder.

[0028] In Example 1 of this invention, the reaction was carried out at 250°C for 6 hours with a mass ratio of alkali source to copper source of 1.3:1, successfully obtaining dendritic copper powder and hydrogen gas. Figure 1 This visually demonstrates the uniform three-dimensional branched structure of dendritic copper powder, with branch lengths ranging from 10 to 30 micrometers. Its high specific surface area is beneficial for subsequent applications (such as conductive materials). Simultaneously, the collected gas was analyzed by gas chromatography. Figure 2 The successful production of hydrogen from methanol reforming was confirmed, with hydrogen yield positively correlated with reaction temperature (hydrogen production increased at higher temperatures or times in Examples 2-9). In this invention, methanol acts as a solvent, reducing agent, and reactant, and the coupled reaction improves efficiency. The analytical results of Examples 2-9 are similar to those of Example 1. The comparative example, reacting at 220°C for 6 hours under the same conditions as Example 1, yielded granular copper powder instead of a dendritic structure, indicating that at temperatures below 250°C, the thermal reduction of methanol is insufficient to guarantee the directional growth of copper ions into a dendritic structure.

[0029] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing dendritic copper powder and co-processing it with methanol reforming to produce hydrogen, characterized in that, The method, in a single reaction system, simultaneously achieves in-situ preparation of dendritic copper powder and methanol liquid-phase reforming for hydrogen production via methanol thermal reduction, and includes the following steps: (1) Dissolve the copper source in methanol to obtain a first solution; dissolve the alkali source in methanol to obtain a second solution; under stirring conditions, add the second solution to the first solution, continue to add additional alkali source, stir and carry out aging treatment to obtain a mixture; (2) The mixture obtained in step (1) is transferred to a reaction vessel and reacted at a temperature of 250°C to 300°C. After the reaction is completed, the mixture is cooled and the generated gas is collected. The liquid and solid mixture in the reaction vessel is separated, washed and dried to obtain dendritic copper powder.

2. The method for preparing dendritic copper powder and co-processing methanol reforming to produce hydrogen according to claim 1, characterized in that, The copper source is copper sulfate pentahydrate.

3. The method for preparing dendritic copper powder and co-processing it with methanol reforming to produce hydrogen according to claim 1, characterized in that, The alkali source is sodium hydroxide.

4. The method for preparing dendritic copper powder and co-processing methanol reforming to produce hydrogen according to claim 1, characterized in that, In step (1), the total amount of the alkali source, calculated as sodium hydroxide, is used in a mass ratio of 1.3 to 2.5:1 with the copper source, calculated as copper sulfate pentahydrate.

5. The method for preparing dendritic copper powder and co-processing it with methanol reforming to produce hydrogen according to claim 1, characterized in that, In step (2), the reaction time is 1 to 6 hours.

6. The method for preparing dendritic copper powder and co-processing methanol reforming to produce hydrogen according to claim 1, characterized in that, The drying process is vacuum drying, and the drying temperature is 40°C to 80°C.

7. The method for preparing dendritic copper powder and co-processing methanol reforming to produce hydrogen according to claim 6, characterized in that, The vacuum drying time is 24-48 hours.

8. The method for preparing dendritic copper powder and co-processing methanol reforming to produce hydrogen according to claim 1, characterized in that, In step (1), the aging process takes 0.5 to 2 hours.

9. The method for preparing dendritic copper powder and co-processing methanol reforming to produce hydrogen according to claim 1, characterized in that, In step (2), the dendritic copper powder has a three-dimensional branched structure.

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