A method for preparing a core-shell structured Ru / CeO2@COF catalyst and its application in the hydrogen evolution reaction of water electrolysis.

Abstract

The application discloses a preparation method of a core-shell structure type Ru / CeO2@COF catalyst, and the method comprises the following steps: firstly, spherical CeO2 particles are added into a polyethylene imine aqueous solution for surface treatment; secondly, the particles are added into anhydrous acetonitrile containing PVP, and then DMTP and TAPB are added, and glacial acetic acid is added for reaction at room temperature and heating reaction to obtain a core-shell type carrier material; and thirdly, after dispersion, RuCl3 methanol solution is added dropwise for ultrasonic treatment, and sodium borohydride solution is added dropwise for reduction to obtain the Ru / CeO2@COF catalyst. The core-shell structure type catalyst is prepared by coating COF on the surface of the spherical cerium oxide to construct a core-shell type carrier material and loading elemental Ru nanoparticles, the specific surface area of the cerium oxide surface is effectively increased, the adsorption capacity of the catalyst is enhanced, the conductivity of the catalyst is improved, and therefore the electrocatalytic activity and stability of the catalyst are improved, and the catalyst is suitable for the field of water electrolysis hydrogen evolution reaction.

Description

Technical Field

[0001] This invention belongs to the field of materials and electrocatalysis technology, specifically relating to a method for preparing a core-shell structured Ru / CeO2@COF catalyst and its application in the hydrogen evolution reaction of water electrolysis. Background Technology

[0002] In recent years, both academia and industry have widely recognized hydrogen energy as a clean and green energy source that can effectively replace fossil fuels. It boasts numerous advantages, including wide availability, high calorific value, cleanliness, and diverse utilization methods. It is the only new energy source that simultaneously meets the requirements of resource conservation, environmental protection, and sustainable development, and is considered the ultimate energy source of the 21st century. Among various industrial hydrogen production technologies, water electrolysis is considered one of the most promising methods for large-scale hydrogen production due to its simple process and high efficiency. In the hydrogen evolution reaction (HER), the high energy required and slow reaction kinetics result in low hydrogen evolution efficiency. Therefore, screening for high-performance catalysts can promote the adsorption of intermediate products and the desorption of products, reducing the activation energy and thus improving hydrogen evolution efficiency.

[0003] The spherical cerium oxide surface contains reversible Ce 3+ / Ce 4+ Redox pairs and tunable oxygen vacancies are considered promising catalytic materials. However, due to their weak adsorption to molecules, the contact between their surface active sites and the substrate is limited, resulting in poor activity for catalyzing HER and failing to effectively promote HER. On the other hand, the poor conductivity of cerium oxide further limits its activity in electrocatalytic HER reactions. Therefore, improving the adsorption capacity of spherical cerium oxide surfaces through surface modification and further enhancing the conductivity of the catalyst using elemental metal nanoparticles is an effective approach to modifying cerium oxide-based catalysts for electrocatalytic HER reactions. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for preparing a core-shell structured Ru / CeO2@COF catalyst, addressing the shortcomings of the prior art. This method uses a surfactant as an inducer to construct a core-shell support material by coating COF onto the surface of spherical cerium oxide through a condensation reaction. Then, a core-shell structured Ru / CeO2@COF catalyst is prepared by loading elemental Ru nanoparticles via surface reduction. This effectively increases the specific surface area of ​​cerium oxide, enhances the catalyst's adsorption capacity, and improves its conductivity, thereby improving the catalyst's electrocatalytic activity and stability. This solves the problems of small specific surface area, poor adsorption capacity, and unsatisfactory conductivity and stability of existing cerium oxide catalysts.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing a core-shell structured Ru / CeO2@COF catalyst, characterized in that the method includes the following steps:

[0006] Step 1: Spherical CeO2 particles are ultrasonically dispersed in water, then polyethyleneimine (PEI) aqueous solution is slowly added and stirred at room temperature. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained.

[0007] Step 2: The CeO2 nanoparticles with PEI surface treatment obtained in Step 1 were added to anhydrous acetonitrile containing PVP and ultrasonically dispersed. Then, 2,5-dimethoxybenzene-1,4-dicarboxaldehyde DMTP and 1,3,5-tris(4-aminophenyl)benzene TAPB were added and stirred. Next, glacial acetic acid was added and reacted at room temperature. Then, glacial acetic acid was added again and the reaction was heated. After centrifugation and washing, the core-shell CeO2@COF support material was obtained.

[0008] Step 3: Dissolve RuCl3 in methanol to prepare RuCl3 methanol solution. Disperse the core-shell CeO2@COF support material obtained in Step 2 in the methanol solution. Then slowly add RuCl3 methanol solution and perform ultrasonic dispersion treatment. Then slowly add sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell structured Ru / CeO2@COF catalyst is obtained.

[0009] To address the shortcomings of cerium oxide, such as small specific surface area, poor adsorption capacity, and unsatisfactory conductivity and stability, this invention uses PEI and PVP surfactants as inducers and utilizes Schiff base condensation reaction to grow covalent organic framework (COF) materials on the cerium oxide surface, forming a shell that coats the spherical cerium oxide surface, thus constructing a core-shell CeO2@COF support material. Then, based on this support, using RuCl3 as a precursor, elemental Ru nanoparticles are uniformly loaded onto the support surface using a surface reduction method to obtain a core-shell Ru / CeO2@COF catalyst. By constructing the core-shell structure, the specific surface area of ​​the cerium oxide surface is increased, and the porous morphology of the COF enhances the catalyst's adsorption capacity, thereby promoting effective contact between the catalyst and the substrate. Furthermore, it effectively prevents the active sites from being covered by surface-aggregated bubbles, reducing agglomeration and increasing the catalyst's stability. This allows for rapid and repeated exposure to the surrounding electrolyte, resulting in rapid mass transfer and contributing to improved electrocatalytic activity.

[0010] The method for preparing a core-shell structured Ru / CeO2@COF catalyst described above is characterized in that the size of the spherical CeO2 particles in step one is 200 nm to 300 nm. By using spherical CeO2 particles with a small particle size and a large specific surface area, the contact area between the catalyst and the electrolyte is further increased, thereby improving the electrocatalytic activity of the catalyst.

[0011] The preparation method of the core-shell structured Ru / CeO2@COF catalyst described above is characterized in that, in step one, the concentration of the spherical CeO2 particles ultrasonically dispersed in water is 10 mg / mL to 40 mg / mL, the concentration of the polyethyleneimine (PEI) aqueous solution is 50 mg / mL to 200 mg / mL, and the mass ratio of PEI to spherical CeO2 particles is 3:1 to 6:1.

[0012] The preparation method of the core-shell structured Ru / CeO2@COF catalyst described above is characterized in that: the ultrasonic dispersion time in step one is 1 hour, and the stirring time at room temperature is 1 hour to 2 hours; the ultrasonic dispersion time in step two is 0.5 hours to 2 hours; and the ultrasonic treatment time in step three is 1 hour to 2 hours.

[0013] The preparation method of the core-shell structured Ru / CeO2@COF catalyst described above is characterized in that the mass ratio of DMTP to TAPB in step two is 40-120:48-144, and the stirring time is 5 min-20 min.

[0014] The preparation method of the core-shell structured Ru / CeO2@COF catalyst described above is characterized in that the reaction time at room temperature in step two is 4h to 6h, and the heating reaction temperature is 80℃ for 12h.

[0015] The method for preparing a core-shell structured Ru / CeO2@COF catalyst described above is characterized in that, in step two, the 2,5-dimethoxyphenyl-1,4-dicarboxaldehyde DMTP and 1,3,5-tris(4-aminophenyl)phenyl TAPB can be replaced with m-phenylenediamine MPA and terephthalaldehyde TPA in a mass ratio of 60–240:72–244. This invention adjusts the shell thickness of the core-shell structure by regulating the amount of ligands DMTP and TAPB added; typically, other ligands with amino and aldehyde groups, such as MPA and TPA, can also be selected as the organic ligand combination for synthesizing COF materials.

[0016] The method for preparing a core-shell Ru / CeO2@COF catalyst described above is characterized in that the Ru loading in the core-shell Ru / CeO2@COF catalyst in step three is 1% to 20% by mass percentage.

[0017] Meanwhile, this invention also discloses the application of a core-shell structured Ru / CeO2@COF catalyst prepared by the method described above in the hydrogen evolution reaction of water electrolysis.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. This invention constructs a core-shell CeO2@COF support material by coating COF onto the surface of spherical cerium oxide, and prepares a core-shell Ru / CeO2@COF catalyst by loading elemental Ru nanoparticles. This effectively increases the specific surface area of ​​cerium oxide, enhances the adsorption capacity of the catalyst, improves the conductivity of the catalyst, and thus improves the electrocatalytic activity and stability of the catalyst.

[0020] 2. This invention uses a covalent organic framework material (COF) as the outer shell of the catalyst. Since COF is a porous material, it will not inhibit the effective contact between the reaction substrate and CeO2 when the Ru / CeO2@COF catalyst is used, which helps to further improve the electrocatalytic activity of the catalyst.

[0021] 3. By coating the surface of spherical cerium oxide with a porous COF shell, this invention not only increases the specific surface area of ​​the catalyst, but also helps to improve the uniformity of the supported elemental Ru nanoparticles, thereby further improving the conductivity of the catalyst and increasing its catalytic efficiency.

[0022] 4. This invention can adjust the shell thickness, shell type, and type and loading amount of the supported metal of the core-shell structure Ru / CeO2@COF catalyst by controlling the condensation reaction conditions and the raw materials, process and reaction conditions of the surface reduction reaction, thereby preparing catalysts with different catalytic activities to meet the needs of hydrogen evolution reaction in water electrolysis in different occasions.

[0023] 5. The surface active materials of the core-shell structured Ru / CeO2@COF catalyst prepared by this invention are uniform in size, evenly distributed, and free from agglomeration. They exhibit strong catalytic activity and electrochemical stability in the electrocatalytic HER reaction.

[0024] 6. The core-shell structured Ru / CeO2@COF catalyst prepared by this invention has strong catalytic activity and is suitable for catalytic water electrolysis and hydrogen evolution reaction. Moreover, the preparation process is simple, easy to operate, and easy to mass-produce. It can prepare a variety of high-performance core-shell structured catalysts and has significant advantages in energy storage and other fields.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1These are TEM images of the core-shell structured Ru / CeO2@COF catalysts prepared in Examples 1 to 4 of this invention.

[0027] Figure 2 The graph shows a comparison of the electrocatalytic hydrogen evolution performance of the core-shell structured Ru / CeO2@COF catalysts prepared in Examples 1-4 of this invention.

[0028] Figure 3 TEM images of the core-shell CeO2@COF support materials prepared in Examples 1 and 5-7 of this invention. Detailed Implementation

[0029] Example 1

[0030] This embodiment includes the following steps:

[0031] Step 1: Spherical CeO2 particles with a size of 200nm to 300nm are ultrasonically dispersed in water at a concentration of 20mg / mL for 1h. Then, 1mL of polyethyleneimine (PEI) aqueous solution with a concentration of 100mg / mL is slowly added and stirred at room temperature for 2h. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained.

[0032] Step 2: 100 mg of CeO2 nanoparticles with PEI surface treatment obtained in Step 1 were added to 150 mL of anhydrous acetonitrile containing 400 mg of PVP and ultrasonically dispersed for 2 h. Then, 40 mg of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde DMTP and 48 mg of 1,3,5-tris(4-aminophenyl)benzene TAPB were added and stirred for 20 min. Next, 2 mL of glacial acetic acid was added and reacted at room temperature for 6 h. Then, 8 mL of glacial acetic acid was added and heated to 80 °C and reacted for 12 h. After centrifugation and washing, the core-shell CeO2@COF support material was obtained.

[0033] Step 3: Dissolve 0.0041 g of RuCl3 in 0.2 mL of methanol, and weigh 200 mg of the core-shell CeO2@COF support material obtained in Step 2 and dissolve it in methanol to prepare a 0.1 mol / L methanol solution. Then, slowly add the RuCl3 methanol solution and perform ultrasonic dispersion treatment for 1 h. Next, slowly add 3.28 mL of 0.1 mol / L sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell Ru / CeO2@COF catalyst is obtained. The Ru loading in the core-shell Ru / CeO2@COF catalyst is 1% by mass.

[0034] Example 2

[0035] The difference between this embodiment and Embodiment 1 is as follows:

[0036] Step 3: Dissolve 0.0108 g of RuCl3 in 0.52 mL of methanol, and weigh 100 mg of the core-shell CeO2@COF support material obtained in Step 2 and dissolve it in methanol to prepare a 0.1 mol / L methanol solution. Then, slowly add the RuCl3 methanol solution and perform ultrasonic dispersion treatment for 1 h. Next, slowly add 8.54 mL of 0.1 mol / L sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell Ru / CeO2@COF catalyst is obtained. The Ru loading in the core-shell Ru / CeO2@COF catalyst is 5% by mass.

[0037] Example 3

[0038] The difference between this embodiment and Embodiment 1 is as follows:

[0039] Step 3: Dissolve 0.0228 g of RuCl3 in 1.00 mL of methanol, and weigh 100 mg of the core-shell CeO2@COF support material obtained in Step 2 and dissolve it in methanol to prepare a 0.1 mol / L methanol solution. Then, slowly add the RuCl3 methanol solution and perform ultrasonic dispersion treatment for 1 h. Next, slowly add 18.07 mL of 0.1 mol / L sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell structured Ru / CeO2@COF catalyst is obtained. The Ru loading in the core-shell structured Ru / CeO2@COF catalyst is 10% by mass.

[0040] Example 4

[0041] The difference between this embodiment and Embodiment 1 is as follows:

[0042] Step 3: Dissolve 0.0512 g of RuCl3 in 0.52 mL of methanol, and weigh 100 mg of the core-shell CeO2@COF support material obtained in Step 2 and dissolve it in methanol to prepare a 0.1 mol / L methanol solution. Then, slowly add the RuCl3 methanol solution and perform ultrasonic dispersion treatment for 1 h. Then, slowly add 40 mL of 0.1 mol / L sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell Ru / CeO2@COF catalyst is obtained. The Ru loading in the core-shell Ru / CeO2@COF catalyst is 20% by mass.

[0043] Figure 1These are TEM images of the core-shell Ru / CeO2@COF catalysts prepared in Examples 1 to 4 of this invention. Figures (a) to (d) correspond to the core-shell Ru / CeO2@COF catalysts with Ru loadings of 1%, 5%, 10%, and 20% in Examples 1 to 4, respectively. The content within the red box in the upper left corner of each figure is a magnified view. Figure 1 Yes, elemental Ru is evenly distributed on the outer shell surface of the catalyst, and the dispersion is relatively uniform. Elemental Ru on the support surface is granular and does not show obvious agglomeration, with a particle size of about 5nm to 10nm.

[0044] The core-shell structured Ru / CeO2@COF catalysts prepared in Examples 1-4 of this invention were tested for their electrocatalytic hydrogen evolution performance. The specific process was as follows: First, 4 mg of catalyst powder was weighed, mixed with 2 mg of conductive carbon, and a small amount of ethanol, binder and water were added. The mixture was sonicated for 30 min, then coated onto a rotating disk electrode, and irradiated under a UV lamp until it dried. Then, the electrochemical hydrogen evolution performance was tested in 0.1 M KOH solution.

[0045] Figure 2 This is a comparison of the electrocatalytic hydrogen evolution performance of the core-shell structured Ru / CeO2@COF catalysts prepared in Examples 1-4 of this invention. Figure 2 It can be seen that, compared with CeO2 and core-shell CeO2@COF support materials, the core-shell Ru / CeO2@COF catalysts prepared in each embodiment all exhibit strong catalytic ability to catalyze the hydrogen evolution reaction of water electrolysis, and their catalytic activity increases with the increase of Ru loading.

[0046] Example 5

[0047] The difference between this embodiment and Embodiment 1 is as follows:

[0048] Step 1: Spherical CeO2 particles with a size of 200nm to 300nm are ultrasonically dispersed in water at a concentration of 10mg / mL for 1h. Then, 1mL of polyethyleneimine (PEI) aqueous solution with a concentration of 40mg / mL is slowly added, and the mixture is stirred at room temperature for 1h. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained.

[0049] Example 6

[0050] The difference between this embodiment and Embodiment 1 is as follows:

[0051] Step 1: Spherical CeO2 particles with a size of 200nm to 300nm are ultrasonically dispersed in water at a concentration of 40mg / mL for 1h. Then, 1mL of polyethyleneimine (PEI) aqueous solution with a concentration of 200mg / mL is slowly added, and the mixture is stirred at room temperature for 1h. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained.

[0052] Example 7

[0053] This embodiment includes the following steps:

[0054] Step 1: Spherical CeO2 particles with a size of 200nm to 300nm are ultrasonically dispersed in water at a concentration of 20mg / mL for 1h. Then, 1mL of polyethyleneimine (PEI) aqueous solution with a concentration of 100mg / mL is slowly added and stirred at room temperature for 1h. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained.

[0055] Step 2: 100 mg of CeO2 nanoparticles with PEI surface treatment obtained in Step 1 were added to 150 mL of anhydrous acetonitrile containing 400 mg of PVP and ultrasonically dispersed for 0.5 h. Then, 60 mg of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde DMTP and 72 mg of 1,3,5-tris(4-aminophenyl)benzene TAPB were added and stirred for 5 min. Next, 2 mL of glacial acetic acid was added and reacted at room temperature for 4 h. Then, 8 mL of glacial acetic acid was added and heated to 80 °C and reacted for 12 h. After centrifugation and washing, the core-shell CeO2@COF support material was obtained.

[0056] Step 3: Dissolve 0.0041 g of RuCl3 in 0.2 mL of methanol, and weigh 200 mg of the core-shell CeO2@COF support material obtained in Step 2 and dissolve it in methanol to prepare a 0.1 mol / L methanol solution. Then, slowly add the RuCl3 methanol solution and perform ultrasonic dispersion treatment for 1 h. Next, slowly add 3.28 mL of 0.1 mol / L sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell Ru / CeO2@COF catalyst is obtained. The Ru loading in the core-shell Ru / CeO2@COF catalyst is 1% by mass.

[0057] Example 8

[0058] This embodiment includes the following steps:

[0059] Step 1: Spherical CeO2 particles with a size of 200nm to 300nm are ultrasonically dispersed in water at a concentration of 20mg / mL for 1h. Then, 1mL of polyethyleneimine (PEI) aqueous solution with a concentration of 100mg / mL is slowly added and stirred at room temperature for 1h. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained.

[0060] Step 2: 100 mg of CeO2 nanoparticles with PEI surface treatment obtained in Step 1 were added to 150 mL of anhydrous acetonitrile containing 400 mg of PVP and ultrasonically dispersed for 0.5 h. Then, 80 mg of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde DMTP and 96 mg of 1,3,5-tris(4-aminophenyl)benzene TAPB were added and stirred for 5 min. Next, 2 mL of glacial acetic acid was added and reacted at room temperature for 4 h. Then, 8 mL of glacial acetic acid was added and heated to 80 °C and reacted for 12 h. After centrifugation and washing, the core-shell CeO2@COF support material was obtained.

[0061] Step 3: Dissolve 0.0041 g of RuCl3 in 0.2 mL of methanol, and weigh 200 mg of the core-shell CeO2@COF support material obtained in Step 2 and dissolve it in methanol to prepare a 0.1 mol / L methanol solution. Then, slowly add the RuCl3 methanol solution and perform ultrasonic dispersion treatment for 1 h. Next, slowly add 3.28 mL of 0.1 mol / L sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell Ru / CeO2@COF catalyst is obtained. The Ru loading in the core-shell Ru / CeO2@COF catalyst is 1% by mass.

[0062] Example 9

[0063] This embodiment includes the following steps:

[0064] Step 1: Spherical CeO2 particles with a size of 200nm to 300nm are ultrasonically dispersed in water at a concentration of 20mg / mL for 1h. Then, 1mL of polyethyleneimine (PEI) aqueous solution with a concentration of 100mg / mL is slowly added and stirred at room temperature for 1h. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained.

[0065] Step 2: 100 mg of CeO2 nanoparticles with PEI surface treatment obtained in Step 1 were added to 150 mL of anhydrous acetonitrile containing 400 mg of PVP and ultrasonically dispersed for 0.5 h. Then, 120 mg of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde DMTP and 144 mg of 1,3,5-tris(4-aminophenyl)benzene TAPB were added and stirred for 5 min. Next, 2 mL of glacial acetic acid was added and reacted at room temperature for 4 h. Then, 8 mL of glacial acetic acid was added and heated to 80 °C and reacted for 12 h. After centrifugation and washing, the core-shell CeO2@COF support material was obtained.

[0066] Step 3: Dissolve 0.0041 g of RuCl3 in 0.2 mL of methanol, and weigh 200 mg of the core-shell CeO2@COF support material obtained in Step 2 and dissolve it in methanol to prepare a 0.1 mol / L methanol solution. Then, slowly add the RuCl3 methanol solution and perform ultrasonic dispersion treatment for 1 h. Next, slowly add 3.28 mL of 0.1 mol / L sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell Ru / CeO2@COF catalyst is obtained. The Ru loading in the core-shell Ru / CeO2@COF catalyst is 1% by mass.

[0067] Figure 3 These are TEM images of the core-shell CeO2@COF support materials prepared in Examples 1 and 7-9 of this invention. Figures (a) to (d) correspond to the core-shell CeO2@COF support materials prepared in Examples 1 and 7-9, respectively. Figures (a1) to (d1) are enlarged views of Figures (a) to (d), respectively. Figure 3 It can be seen that in the core-shell CeO2@COF carrier materials prepared in each embodiment, the COF shell tightly covers the CeO2 particles, and the COF shell thickens significantly with the increase of COF precursor dosage.

[0068] Example 10

[0069] This embodiment includes the following steps:

[0070] Step 1: Spherical CeO2 particles with a size of 200nm to 300nm are ultrasonically dispersed in water at a concentration of 20mg / mL for 1h. Then, 1mL of polyethyleneimine (PEI) aqueous solution with a concentration of 100mg / mL is slowly added and stirred at room temperature for 1h. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained.

[0071] Step 2: 100 mg of CeO2 nanoparticles with PEI surface treatment obtained in Step 1 were added to 150 mL of anhydrous acetonitrile containing 400 mg PVP and ultrasonically dispersed for 0.5 h. Then, 240 mg of terephthalaldehyde (TPA) and 288 mg of m-phenylenediamine (MPA) were added and stirred for 5 min. Next, 2 mL of glacial acetic acid was added and reacted at room temperature for 4 h. Then, 8 mL of glacial acetic acid was added and heated to 80 °C and reacted for 12 h. After centrifugation and washing, the core-shell CeO2@COF support material was obtained.

[0072] Step 3: Dissolve 0.0041 g of RuCl3 in 0.2 mL of methanol, and weigh 200 mg of the core-shell CeO2@COF support material obtained in Step 2 and dissolve it in methanol to prepare a 0.1 mol / L methanol solution. Then, slowly add the RuCl3 methanol solution and perform ultrasonic dispersion treatment for 1 h. Next, slowly add 3.28 mL of 0.1 mol / L sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell Ru / CeO2@COF catalyst is obtained. The Ru loading in the core-shell Ru / CeO2@COF catalyst is 1% by mass.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a core-shell structured Ru / CeO2@COF catalyst, characterized in that, The method includes the following steps: Step 1: Spherical CeO2 particles are ultrasonically dispersed in water, then polyethyleneimine (PEI) aqueous solution is slowly added and stirred at room temperature. After centrifugation and washing, CeO2 nanoparticles with PEI surface treatment are obtained. Step 2: The CeO2 nanoparticles with PEI surface treatment obtained in Step 1 were added to anhydrous acetonitrile containing PVP and ultrasonically dispersed. Then, 2,5-dimethoxybenzene-1,4-dicarboxaldehyde DMTP and 1,3,5-tris(4-aminophenyl)benzene TAPB were added and stirred. Next, glacial acetic acid was added and reacted at room temperature. Then, glacial acetic acid was added again and the reaction was heated. After centrifugation and washing, the core-shell CeO2@COF support material was obtained. Step 3: Dissolve RuCl3 in methanol to prepare RuCl3 methanol solution. Disperse the core-shell CeO2@COF support material obtained in Step 2 in the methanol solution. Then slowly add RuCl3 methanol solution and perform ultrasonic dispersion treatment. Then slowly add sodium borohydride aqueous solution for reduction. After repeated washing, centrifugation and drying, the core-shell structured Ru / CeO2@COF catalyst is obtained.

2. The method for preparing a core-shell structured Ru / CeO2@COF catalyst according to claim 1, characterized in that, The size of the spherical CeO2 particles mentioned in step one is 200nm~300nm.

3. The method for preparing a core-shell structured Ru / CeO2@COF catalyst according to claim 1, characterized in that, In step one, the concentration of the spherical CeO2 particles ultrasonically dispersed in water is 10 mg / mL to 40 mg / mL, the concentration of the polyethyleneimine (PEI) aqueous solution is 50 mg / mL to 200 mg / mL, and the mass ratio of PEI to spherical CeO2 particles is 3:1 to 6:

1.

4. The method for preparing a core-shell structured Ru / CeO2@COF catalyst according to claim 1, characterized in that, The ultrasonic dispersion time in step one is 1 hour, and the stirring time at room temperature is 1 hour to 2 hours; the ultrasonic dispersion time in step two is 0.5 hours to 2 hours; and the ultrasonic dispersion treatment time in step three is 1 hour to 2 hours.

5. The method for preparing a core-shell structured Ru / CeO2@COF catalyst according to claim 1, characterized in that, In step two, the mass ratio of DMTP to TAPB is 40~120:48~144, and the stirring time is 5min~20min.

6. The method for preparing a core-shell structured Ru / CeO2@COF catalyst according to claim 1, characterized in that, The reaction time at room temperature in step two is 4 to 6 hours, and the heating reaction temperature is 80°C for 12 hours.

7. The method for preparing a core-shell structured Ru / CeO2@COF catalyst according to claim 1, characterized in that, In step two, the 2,5-dimethoxybenzene-1,4-dicarboxaldehyde DMTP and 1,3,5-tris(4-aminophenyl)benzene TAPB can also be replaced with m-phenylenediamine MPA and terephthalaldehyde TPA in a mass ratio of 60~240:72~244.

8. The method for preparing a core-shell structured Ru / CeO2@COF catalyst according to claim 1, characterized in that, The Ru loading in the core-shell structured Ru / CeO2@COF catalyst described in step three is 1% to 20% by mass.

9. The application of a core-shell Ru / CeO2@COF catalyst prepared by the method according to any one of claims 1 to 8 in the hydrogen evolution reaction of water electrolysis.

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