A cobalt / boron-nitride nanosheet (CoB / NF) sodium borohydride hydrolysis catalyst, preparation method and application
By preparing CoB/NF composite materials, the problems of insufficient stability and activity of existing catalysts were solved, and efficient and stable hydrogen production by sodium borohydride hydrolysis was achieved, which is suitable for stable hydrogen supply in hydrogen fuel cells.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI CHUNJIA ENERGY TECH CO LTD
- Filing Date
- 2026-05-06
- Publication Date
- 2026-07-21
AI Technical Summary
Existing catalyst loading methods suffer from poor coating effects, low catalytic activity, short lifespan, and low stability. Furthermore, electroplating equipment is complex and unsuitable for large-scale production.
CoB powder was mixed with PVDF binder, coated onto a nickel foam support substrate, and then annealed to prepare a CoB/NF composite material. This simplified the preparation process and improved the stability and activity of the catalyst.
The prepared CoB/NF catalyst exhibits high catalytic activity and long lifespan, making it suitable for large-scale production. It is applicable to hydrogen production via sodium borohydride hydrolysis, significantly improving the stable hydrogen supply capability of hydrogen fuel cells.
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Figure CN122424818A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a catalyst for hydrogen production by hydrolysis of sodium borohydride, particularly a CoB / NF sodium borohydride hydrolysis catalyst, its preparation method, and its application. Background Technology
[0002] The massive consumption of non-renewable energy sources (such as oil, coal, and natural gas) has exacerbated environmental pollution, forcing the search for sustainable and clean energy alternatives to accelerate. Among the many options, hydrogen, with its extremely high calorific value (142 MJ / kg) and environmentally friendly combustion products (mainly water), has become one of the most promising energy carriers. Hydrogen energy can be utilized through combustion heating or fuel cell power generation. Fuel cell technology, due to its high conversion efficiency (typically above 50-60%), high specific power, and high specific energy, is considered the core of the next-generation power source, with enormous potential in transportation, power generation, and other fields. With the continuous breakthroughs in fuel cell technology and the accelerated commercialization process, ensuring a safe, efficient, and economical hydrogen supply has become a key bottleneck and a core problem that urgently needs to be solved to determine its widespread application.
[0003] Sodium borohydride has attracted widespread attention due to its high hydrogen storage density (10.6 wt.%), and sodium borohydride hydrolysis hydrogen production technology can conveniently, practically, and efficiently obtain high-purity hydrogen, making it one of the best hydrogen sources for small-power hydrogen fuel cells. During sodium borohydride hydrolysis, the use of highly efficient catalysts can achieve high hydrogen production rates and rapid reaction start-up. Commonly used catalysts include precious metal catalysts such as ruthenium and platinum, as well as transition metal catalysts such as nickel and cobalt. To reduce costs, precious metal catalysts are usually supported on a carrier in practical applications, which reduces the amount used and improves stability.
[0004] In existing technologies, catalyst loading methods mainly include chemical plating and electroplating. Chemical plating typically involves direct chemical plating on the support, resulting in poor coating quality, low catalytic activity, short catalytic lifetime, and low stability. While electroplating can yield highly active catalysts, it requires specialized equipment, is time-consuming, and demands sophisticated processes, making it unsuitable for large-scale production. Summary of the Invention
[0005] To address the above problems, this invention provides a method for preparing a CoB / NF sodium borohydride hydrolysis catalyst, the specific technical solution of which is as follows: A method for preparing a CoB / NF sodium borohydride hydrolysis catalyst includes the following steps: reacting cobalt chloride hexahydrate with sodium borohydride to prepare a CoB powder catalyst; mixing the CoB powder catalyst with a binder PVDF and adding NMP to form a slurry; coating the slurry onto a nickel foam support substrate, and then annealing to remove the NMP solvent to obtain a CoB / NF composite material.
[0006] Preferably, the preparation of the CoB powder catalyst includes the following steps: weighing a certain amount of cobalt chloride hexahydrate and sodium borohydride powder and preparing them as a solvent; slowly pouring the sodium borohydride solution from step 1 into the cobalt chloride hexahydrate solution while continuously stirring; after standing, filtering out the black precipitate and washing it several times with deionized water; placing the collected product in a vacuum drying oven for drying; pulverizing the dried product to obtain a uniform CoB powder material.
[0007] Preferably, the preparation of the CoB / NF composite material includes the following steps: taking an appropriate amount of CoB powder and PVDF powder, and adding an appropriate amount of NMP solution; mixing evenly with a magnetic stirrer to form a uniform viscous ink; uniformly coating the viscous ink onto the surface of nickel foam by a scraping method; transferring the nickel foam coated with CoB material to a forced-air drying oven, and obtaining the CoB / NF composite material after drying.
[0008] A method for preparing a sodium borohydride hydrolysis hydrogen production catalyst includes the following steps: (1) Preparation of CoB powder materials Step 1: Weigh a certain amount of cobalt chloride and sodium borohydride powder and prepare a solvent; Step 2: Slowly pour the sodium borohydride solution from Step 1 into the cobalt chloride solution while continuously stirring; Step 3: After standing for one hour, filter out the black precipitate and wash it several times with deionized water; Step 4: The collected product is placed in a vacuum drying oven for drying; Step 5: Grind the dried product in a mortar and pestle to obtain a uniform CoB powder material; (2) Preparation of CoB / NF composite catalyst materials Step 6: Take an appropriate amount of CoB powder and PVDF powder materials, and add an appropriate amount of NMP solution to them. Step 7: Mix thoroughly using a magnetic stirrer to form a uniform, viscous ink; Step 8: Apply the ink obtained in Step 7 evenly to the surface of the nickel foam using a scraping method; Step 9: Preheat the drying oven, quickly transfer the nickel foam coated with CoB material into the drying oven, and obtain the CoB / NF composite material after drying.
[0009] In a preferred embodiment of the preparation method described in this invention, the molar ratio of cobalt chloride to sodium borohydride is 1:2.
[0010] As a preferred embodiment of the preparation method described in this invention, the temperature of the vacuum drying oven is 60 degrees Celsius, and the temperature is maintained for 12 hours.
[0011] In a preferred embodiment of the preparation method described in this invention, the mass ratio of CoB powder to PVDF powder is 7:3.
[0012] As a preferred embodiment of the preparation method described in this invention, the magnetic stirring time is 2 hours and the rotation speed is 1200 revolutions per minute.
[0013] As a preferred embodiment of the preparation method described in this invention, the blowing drying temperature is 220 degrees Celsius and the time is 5 hours.
[0014] A CoB / NF sodium borohydride hydrolysis catalyst is prepared by the aforementioned method for preparing a CoB / NF sodium borohydride hydrolysis catalyst.
[0015] Application of a CoB / NF sodium borohydride hydrolysis catalyst, said catalyst for hydrogen production by hydrolysis of sodium borohydride.
[0016] This invention provides a method for preparing a sodium borohydride hydrolysis catalyst, and describes the application of the prepared CoB / NF sodium borohydride hydrolysis catalyst in hydrogen fuel cells.
[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing a CoB / NF sodium borohydride hydrolysis catalyst. CoB powder catalyst is prepared by reacting cobalt chloride with sodium borohydride. This CoB powder catalyst is then mixed with a binder (PVDF) and NMP is added to form a slurry, which is then coated onto a nickel foam support substrate. Annealing removes the NMP solvent, yielding the CoB / NF composite material. This preparation method is simple to operate, easy to scale up, and the prepared catalyst exhibits excellent stability, high catalytic activity, and low preparation cost. It shows promising application prospects in the field of rapid hydrogen production via sodium borohydride hydrolysis.
[0018] Using nickel foam as a catalyst support, nickel foam has a high specific surface area and a through-hole network, which can significantly increase the exposure of active sites and promote the diffusion and mass transfer of reactants (NaBH4 solution) and products (H2); in addition, nickel foam has good thermal conductivity, ductility and alkali corrosion resistance.
[0019] CoB nanoparticles possess abundant amorphous structures and surface defects. The boron atoms optimize the electronic structure of cobalt active sites through their electron-deficient properties, enhancing the adsorption capacity for reaction intermediates. Furthermore, CoB maintains high activity even in environments containing impurities, making it suitable for practical industrial applications.
[0020] Using PVDF as a binder can firmly fix CoB powder to the NF surface, preventing particle detachment, improving catalyst mechanical stability, and significantly extending catalyst lifetime. The PVDF-supported method is simple, requires no complex deposition equipment, and is suitable for large-scale preparation.
[0021] Hydrogen can be produced stably by catalytically pumping in sodium borohydride solution, thus enabling a stable hydrogen supply for hydrogen fuel cells. Attached Figure Description
[0022] Figure 1 This is a graph showing (a) hydrogen production and (b) corresponding hydrogen production rate of the composite materials of Example 1 and Comparative Examples 1-3 after 5 cycles at 298K. Figure 2 This is a graph showing (a) hydrogen production and (b) corresponding hydrogen production rate of the composite materials of Example 1 and Comparative Examples 1-3 after 5 cycles at 318K. Figure 3 This application shows the relationship between (a) hydrogen production and time at different temperatures and (b) the activation energy diagram of the catalyst in Example 1 at different temperatures. Figure 4 This is the relationship between hydrogen production and time in the cyclic test of Embodiment 1 of this application, (b) the hydrogen production rate corresponding to the cyclic test; Figure 5 This is the discharge power diagram of the hydrogen fuel cell in Application Example 1 of this application. Detailed Implementation
[0023] The present invention will now be further described with reference to the accompanying drawings.
[0024] Unless otherwise specified, the methods used in the embodiments are conventional methods; unless otherwise specified, the materials and reagents used are commercially available.
[0025] This application provides a method for preparing a CoB / NF sodium borohydride hydrolysis catalyst, which uses nickel foam as a substrate and supports nano-CoB powder with a binder.
[0026] The purpose of this application is to provide a simple and efficient method for preparing a sodium borohydride hydrolysis catalyst for hydrogen production. This application first prepares a CoB non-metallic catalyst active material using a chemical reduction method, and then effectively binds the CoB catalyst onto nickel foam using a PVDF binder. By adjusting the ratio of the CoB catalyst to the binder, its active sites are fully exposed. The resulting CoB / NF catalyst exhibits high catalytic activity, long catalytic lifetime, and corrosion resistance. The preparation method is simple and suitable for large-scale production.
[0027] Example 1 (Preparation of CoB / NF (7:3) catalyst) 20 mmol of cobalt chloride hexahydrate was weighed and prepared into 100 mL of aqueous solution, and 40 mmol of sodium borohydride was prepared into 300 mL of aqueous solution. The sodium borohydride aqueous solution was then slowly poured into the cobalt chloride hexahydrate aqueous solution while stirring (the molar ratio of cobalt chloride hexahydrate to sodium borohydride was 1:2). After standing for 2 hours, the black precipitate was filtered off and then soaked and rinsed three times with deionized water. Finally, the material was dried in a vacuum drying oven at 60℃ for 12 hours. The dried material was then thoroughly ground to obtain CoB powder catalyst.
[0028] Take 0.7g of the prepared CoB powder catalyst, add 0.3g of PVDF powder binder and grind thoroughly; then add 5mL of NMP solution and stir with a magnetic stirrer at 1200 rpm for 2 hours. Take an appropriate amount of ink and evenly coat it on a 2×2cm nickel foam, and transfer the nickel foam to a 220℃ forced-air drying oven to dry for 5 hours to obtain the CoB / NF (7:3) catalyst.
[0029] Comparative Example 1 (Preparation of CoB / NF (9:1) catalyst) 20 mmol of cobalt chloride hexahydrate was weighed and prepared into 100 mL of aqueous solution, and 40 mmol of sodium borohydride was prepared into 300 mL of aqueous solution. The sodium borohydride aqueous solution was then slowly poured into the cobalt chloride hexahydrate aqueous solution while stirring (the molar ratio of cobalt chloride hexahydrate to sodium borohydride was 1:2). After standing for 2 hours, the black precipitate was filtered off and then soaked and rinsed three times with deionized water. Finally, the material was dried in a vacuum drying oven at 60℃ for 12 hours. The dried material was then thoroughly ground to obtain CoB powder catalyst.
[0030] Take 0.9g of the prepared CoB powder catalyst, add 0.1g of PVDF powder binder and grind thoroughly; then add 5mL of NMP solution and stir with a magnetic stirrer at 1200 rpm for 2 hours. Take an appropriate amount of ink and evenly coat it on a 2×2cm nickel foam, and transfer the nickel foam to a 220℃ forced-air drying oven to dry for 5 hours to obtain the CoB / NF (9:1) catalyst.
[0031] Comparative Example 2 (Preparation of CoB / NF (8:2) catalyst) 20 mmol of cobalt chloride hexahydrate was weighed and prepared into 100 mL of aqueous solution, and 40 mmol of sodium borohydride was prepared into 300 mL of aqueous solution. The sodium borohydride aqueous solution was then slowly poured into the cobalt chloride hexahydrate aqueous solution while stirring (the molar ratio of cobalt chloride hexahydrate to sodium borohydride was 1:2). After standing for 2 hours, the black precipitate was filtered off and then soaked and rinsed three times with deionized water. Finally, the material was dried in a vacuum drying oven at 60℃ for 12 hours. The dried material was then thoroughly ground to obtain CoB powder catalyst.
[0032] Take 0.8g of the prepared CoB powder catalyst, add 0.2g of PVDF powder binder and grind thoroughly; then add 5mL of NMP solution and stir with a magnetic stirrer at 1200 rpm for 2 hours. Take an appropriate amount of ink and evenly coat it on a 2×2cm nickel foam, and transfer the nickel foam to a 220℃ forced-air drying oven to dry for 5 hours to obtain the CoB / NF (8:2) catalyst.
[0033] Comparative Example 3 (Preparation of CoB / NF (6:4) catalyst) 20 mmol of cobalt chloride hexahydrate was weighed and prepared into 100 mL of aqueous solution, and 40 mmol of sodium borohydride was prepared into 300 mL of aqueous solution. The sodium borohydride aqueous solution was then slowly poured into the cobalt chloride hexahydrate aqueous solution while stirring (the molar ratio of cobalt chloride hexahydrate to sodium borohydride was 1:2). After standing for 2 hours, the black precipitate was filtered off and then soaked and rinsed three times with deionized water. Finally, the material was dried in a vacuum drying oven at 60℃ for 12 hours. The dried material was then thoroughly ground to obtain CoB powder catalyst.
[0034] Take 0.6g of the prepared CoB powder catalyst, add 0.4g of PVDF powder binder and grind thoroughly; then add 5mL of NMP solution and stir with a magnetic stirrer at 1200 rpm for 2 hours. Take an appropriate amount of ink and evenly coat it on a 2×2cm nickel foam, and transfer the nickel foam to a 220℃ forced-air drying oven to dry for 5 hours to obtain the CoB / NF (6:4) catalyst.
[0035] Application Example 1 The catalyst prepared in Example 1 was stacked into a cylindrical shape and pumped into a sodium borohydride reaction solution via a gear pump. The hydrogen produced after contacting the catalyst in Example 1 underwent gas-liquid separation and purification before being fed into the hydrogen fuel cell stack. The reaction waste liquid passed through a CoB / NF foam mesh catalyst and entered a waste liquid tank. The hydrogen production was controlled by the amount of sodium borohydride pumped in to ensure the normal operation of the hydrogen fuel cell stack. Hydrogen pressure and flow rate were monitored using pressure gauges and gas flow meters, and the stack power was monitored using software.
[0036] Catalyst testing Hydrogen evolution volume test: Add 40 mL of 160 g / L NaBH4 aqueous solution (containing 40 g / L NaOH) to a 500 mL three-necked round-bottom flask. Then place the flask in a 25°C water bath and stir continuously for 30 minutes until the reaction solution is maintained at 25°C. Add 100 mg of catalyst to the test solution. Collect the generated gas by water displacement and obtain the volume of the generated gas directly through a graduated cylinder.
[0037] The hydrogen evolution rate (HGR) test is calculated according to the following formula (1): in t is the displacement, m is the catalyst mass, and t is the total reaction time.
[0038] Catalyst activation energy test: The hydrolysis of NaBH4 was tested at different temperatures (25℃, 30℃, 35℃, 40℃, and 45℃). The hydrogen evolution rate increased with increasing test temperature. According to the Arrhenius equation, the relationship between temperature and hydrogen evolution rate is obtained (2): Where k is the reaction rate (Lmin) -1 g -1 Ea is the activation energy (kJ / mol). -1 R is the gas constant (8.314 J / mol). - 1 K -1 T and T are the actual reaction temperatures (K). According to the above equation, Ink (rate constant) is inversely proportional to temperature.
[0039] Catalyst cycle stability test: After the first test, the CoB / NF catalyst was removed, rinsed with deionized water and dried, and 40 mL of sodium borohydride reaction solution was added. The CoB / NF catalyst was then added again and the hydrogen production was recorded.
[0040] Results Analysis Depend on Figure 1 (a) It can be seen that, at 298K temperature and in the same amount of time, Example 1 produces the most hydrogen gas. The hydrogen evolution rate of Example 1 and Comparative Examples 1-3 can be calculated using formula (1). Figure 1 (b) It can be demonstrated that Example 1 has the best hydrogen production rate at room temperature of 25°C.
[0041] Depend on Figure 2 (a) It can be seen that, at 318 K temperature and in the same amount of time, Example 1 produces the most hydrogen gas. The hydrogen evolution rate of Example 1 and Comparative Examples 1-3 can be calculated using formula (1). Figure 2 (b) It can be demonstrated that Example 1 has the best hydrogen production rate at a high temperature of 45°C.
[0042] Figure 3 This demonstrates that the hydrogen desorption relationship of sodium borohydride water in Example 1 was studied within the temperature range of 298-318 K. Figure 1 (a) It can be observed that, within the same time frame, the higher the temperature, the more hydrogen gas is produced. This can be calculated using the Arrhenius equation as follows: Figure 3(b) The activation energy of Example 1 shown is relatively low, which is one of the reasons for the excellent performance of the catalyst.
[0043] Figure 4 The results show the cycle stability obtained through repeated cycle tests, which is one of the important indicators for evaluating catalyst performance. Figure 4 As shown in (a), the catalyst performance degradation was relatively small in each cycle test. After five cycles, the catalyst in Example 1 still maintained high catalytic activity and excellent stability. Figure 4 (b) It can be seen that the hydrogen evolution rate in the alkaline sodium borohydride aqueous solution of the example is as high as 3410 mL H2 min. -1 g -1 Under the same conditions, it is superior to most existing non-precious metal catalyst composite materials.
[0044] Figure 5 The diagram shows the power output of a hydrogen fuel cell stack driven by the catalytic hydrolysis of basic sodium borohydride using the catalyst of Example 1 in Application Example 1. By stabilizing the voltage at 48V and gradually increasing the current, the output power can eventually be stabilized at 1035W, which can meet the normal power supply needs of most electrical appliances.
[0045] Therefore, the CoB / NF supported sodium borohydride hydrolysis catalyst synthesized by the present invention exhibits excellent catalytic activity and long service life in high-concentration sodium borohydride aqueous solutions. The catalyst retains extremely high reactivity after five cycles and can be used as a hydrogen source in hydrogen fuel cells.
[0046] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the claims of the present invention.
Claims
1. A method for preparing a CoB / NF sodium borohydride hydrolysis catalyst, characterized in that, Includes the following steps: CoB powder catalyst was prepared by reacting cobalt chloride hexahydrate with sodium borohydride. The CoB powder catalyst was mixed with the binder PVDF and NMP was added to prepare a slurry; The slurry was coated onto a nickel foam support substrate, and then annealed to remove the NMP solvent, resulting in a CoB / NF composite material.
2. The method for preparing a CoB / NF sodium borohydride hydrolysis catalyst according to claim 1, characterized in that, The preparation of the CoB powder catalyst includes the following steps: Weigh out a certain amount of cobalt chloride hexahydrate and sodium borohydride powder and prepare a solvent; Slowly pour the sodium borohydride solution from step 1 into the cobalt chloride hexahydrate solution while continuously stirring; After standing, filter out the black precipitate and wash it several times with deionized water; The collected products were placed in a vacuum drying oven for drying; The product was pulverized and dried to obtain a uniform CoB powder material.
3. The method for preparing a CoB / NF sodium borohydride hydrolysis catalyst according to claim 2, characterized in that, The molar ratio of cobalt chloride hexahydrate to sodium borohydride is 1:
2.
4. The method for preparing a CoB / NF sodium borohydride hydrolysis catalyst according to claim 2, characterized in that, The drying temperature of the vacuum drying oven is 60±5℃.
5. A method for preparing a CoB / NF sodium borohydride hydrolysis catalyst according to any one of claims 1 to 4, characterized in that, The preparation of the CoB / NF composite material includes the following steps: Take an appropriate amount of CoB powder and PVDF powder, and add an appropriate amount of NMP solution to them; Mix thoroughly using a magnetic stirrer to form a uniform, viscous ink. The viscous ink was evenly coated onto the surface of the nickel foam using a scraping method. The nickel foam coated with CoB material was transferred to a forced-air drying oven and dried to obtain the CoB / NF composite material.
6. The method for preparing a CoB / NF sodium borohydride hydrolysis catalyst according to claim 5, characterized in that, The mass ratio of CoB powder to PVDF powder is 7:
3.
7. The method for preparing a CoB / NF sodium borohydride hydrolysis catalyst according to claim 5, characterized in that, The drying temperature of the blower drying oven is 220±10℃.
8. The method for preparing a CoB / NF sodium borohydride hydrolysis catalyst according to claim 5, characterized in that, During drying, preheat the drying oven and quickly transfer the CoB-coated nickel foam into the drying oven.
9. A CoB / NF sodium borohydride hydrolysis catalyst, characterized in that, The catalyst was prepared by the method described in any one of claims 1 to 8.
10. The application of the CoB / NF sodium borohydride hydrolysis catalyst according to claim 9, characterized in that, The catalyst is used for hydrogen production by hydrolysis of sodium borohydride.