A pyrazolyl porous organic polymer supported ruthenium nanocluster material, a preparation method and application thereof
By supporting ruthenium nanoclusters with pyrazole-based porous organic polymers, the aggregation problem of ruthenium nanoclusters in the electrocatalytic process was solved, achieving highly efficient electrocatalytic hydrogen evolution performance, especially exhibiting excellent catalytic activity and stability in alkaline media.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGXI NORMAL UNIV
- Filing Date
- 2026-04-25
- Publication Date
- 2026-06-05
AI Technical Summary
In existing technologies, ruthenium nanoclusters suffer from aggregation problems during synthesis and electrocatalysis, leading to decreased catalytic activity and making it difficult to achieve their efficient application in alkaline media.
Using pyrazole-based porous organic polymers as carriers, pyrazole-based porous organic polymers (Pz-POP) were prepared through polycondensation reaction. Then, ruthenium nanoclusters supported on Pz-POP (Ru@Pz-POP) materials were prepared by liquid-phase sodium borohydride reduction method, realizing the controllable synthesis and dispersion of ruthenium nanoclusters.
The prepared Ru@Pz-POP material exhibits excellent electrocatalytic hydrogen evolution performance in alkaline media, requiring only 8 mV overpotential to obtain a current density of 10 mA/cm2, and operates stably at high current density for 100 h, demonstrating good catalytic activity and stability.
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Figure CN122147445A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of nanomaterial synthesis and energy electrocatalysis, specifically to a pyrazole-based porous organic polymer-supported ruthenium nanoclusters, its preparation method, and its applications. Background Technology
[0002] Hydrogen production via water electrolysis driven by intermittent renewable energy sources provides a reliable pathway to carbon neutrality. The hydrogen evolution reaction (HER), a key half-reaction in water electrolysis, suffers kinetic stagnation in alkaline media due to the slow water dissociation step. While platinum (Pt) is currently recognized as a highly efficient HER catalyst, its reaction rate under alkaline conditions is 2-3 orders of magnitude lower than in acidic media, and its stability is poor. Therefore, developing high-performance alkaline HER catalysts is essential. Ruthenium (Ru) has attracted considerable attention due to its Pt-like intrinsic activity, superior alkalinity resistance, and lower cost. The catalytic performance of metal nanoparticles is closely related to their size. Typically, metal nanoclusters (<3.0 nm) exhibit enhanced catalytic activity due to their high atom utilization, abundant unsaturated / dangling bonds, and fully exposed active sites. However, metal nanoclusters possess high surface free energy, making them prone to aggregation during synthesis or electrocatalysis, affecting their catalytic activity and stability. Achieving controllable synthesis of Ru nanoclusters and effectively reducing their aggregation during electrocatalysis remains a challenge. Summary of the Invention
[0003] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a pyrazole-based porous organic polymer-supported ruthenium nanoclusters material, its preparation method and application, so as to solve the technical problem of controllable synthesis of Ru nanoclusters and the decrease in activity caused by agglomeration during electrocatalysis.
[0004] Porous organic polymers (POPs) are a novel class of porous materials composed of molecular building blocks. First, POPs can be custom-designed to exhibit a rich variety of structures and morphologies. Second, the molecular platform constructed from POPs enables precise atomic-level control of nano / sub-nanometer confined spaces and functional groups, thereby accurately manipulating the size, dispersion, and microenvironment of metal nanoparticles. POPs are rich in highly ordered micropores (<2 nm) and unique pore surface properties. The spatial confinement effect of their pores and the coordination confinement effect of their functional groups can increase the migration energy barrier of metal atoms without the need for surfactants, thus reducing metal migration and aggregation during synthesis, leading to the synthesis of highly dispersed metal nanoclusters and even single metal atoms. Furthermore, POPs can act as structural stabilizers and electronic modifiers for metal nanoclusters, enhancing their catalytic activity and stability.
[0005] Therefore, this invention utilizes a pyrazole-based porous organic polymer to confine and synthesize highly dispersed ruthenium nanoclusters. Specifically, this invention prepares a pyrazole-based porous organic polymer (Pz-POP) material through the polycondensation reaction of 2,4,6-tricarboxymethyl phloroglucinol and 1H-pyrazole-3,5-diamine. Subsequently, ruthenium (Ru) nanoclusters-supported Pz-POP (Ru@Pz-POP) material is prepared using a liquid-phase sodium borohydride reduction method. The synthesized Pz-POP material exhibits a nanowire morphology, with the Ru nanoclusters having a particle size of approximately 2.5 nm. The Pz-POP material prepared by this invention demonstrates excellent electrocatalytic hydrogen evolution reaction performance and has potential application prospects in electrocatalytic hydrogen evolution.
[0006] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for preparing ruthenium nanoclusters supported by a pyrazole-based porous organic polymer, comprising the following steps: S1. A pyrazole-based porous organic polymer was prepared by polycondensation of 2,4,6-tricarboxymethyl phloroglucinol and 1H-pyrazole-3,5-diamine. S2. The pyrazole-based porous organic polymer and ruthenium salt are mixed, and a reducing agent is added to prepare ruthenium nanoclusters supported on the pyrazole-based porous organic polymer.
[0007] In a preferred embodiment of the present invention, step S1 includes the following specific steps: 2,4,6-tricarboxymethyl phloroglucinol and 1H-pyrazole-3,5-diamine were placed in a pressure-resistant tube, and 1,4-dioxane and mesitylene were added and mixed evenly. Then, acetic acid solution was added and mixed evenly. The pressure-resistant tube was frozen and sealed, and then placed in a constant temperature oven for reaction to obtain the pyrazole-based porous organic polymer-supported ruthenium nanoclusters material.
[0008] In a preferred embodiment of the present invention, the molar ratio of 2,4,6-tricarboxymethyl phloroglucinol and 1H-pyrazole-3,5-diamine is 2:3, the volume ratio of 1,4-dioxane, mesitylene, and acetic acid solution is 3:3:1, and the concentration of acetic acid solution is 3~6 mol·L⁻¹. 1 .
[0009] In a preferred embodiment of the present invention, the freezing method is to freeze in liquid nitrogen for 25-35 hours.
[0010] The reaction temperature is 100~160℃, and the reaction time is 2~5 days.
[0011] In a preferred embodiment of the present invention, step S2 includes the following specific steps: The pyrazol-based porous organic polymer was dispersed in water, and ruthenium salt was added and mixed for 10-14 h to obtain a mixture. A reducing agent was added to the mixture, and the mixture was mixed for 1-3 hours. The product was obtained by centrifugation, and the product was washed and dried to prepare pyrazole-based porous organic polymer-supported ruthenium nanoclusters.
[0012] In a preferred embodiment of the present invention, in step S2, the ruthenium salt includes at least one of ruthenium chloride, sulfate, nitrate, acetate, and salt hydrate; the concentration of the ruthenium salt in the mixture is 0.01~0.03 mol·L⁻¹. 1 The molar ratio of the pyrazole-based porous organic polymer to the ruthenium salt is 1 to 3:1.
[0013] In a preferred embodiment of the present invention, in step S2, the reducing agent is a borohydride, which is at least one of sodium borohydride and potassium borohydride, and the molar ratio of the borohydride to the ruthenium salt is 5~20:1.
[0014] Specifically, this invention provides a method for preparing ruthenium nanoclusters supported by pyrazole-based porous organic polymers, comprising the following steps: (1) Preparation of pyrazole-based porous organic polymer (Pz-POP): 2,4,6-tricarboxymethyl phloroglucinol and 1H-pyrazole-3,5-diamine were placed in a pressure-resistant tube, dissolved in 1,4-dioxane, and then mesitylene was added. The mixture was sonicated for 10-30 min, followed by the addition of 3-6 mol·L⁻¹ 1 The acetic acid solution was then used. The pressure-resistant tube was then rapidly frozen and sealed in a liquid nitrogen bath. It was then placed in a constant temperature oven at 100–160°C for 2–5 days. After cooling, it was centrifuged, washed with acetone, and dried to obtain Pz-POP. (2) Preparation of Pz-POP supported ruthenium nanoclusters (Ru@Pz-POP): Pz-POP was dispersed in deionized water and ultrasonically dispersed for 10-30 min. Metallic ruthenium salt was added and stirred at room temperature for 4-12 h. Then, an aqueous solution of borohydride was added dropwise, and stirring was continued for 1-2 h. After centrifugation, the product was washed with water and ethanol and dried to obtain Ru@Pz-POP.
[0015] Secondly, the present invention provides a pyrazole-based porous organic polymer-supported ruthenium nanoclusters material, which is obtained by the preparation method described above.
[0016] In a preferred embodiment of the present invention, the pyrazole-based porous organic polymer-supported ruthenium nanoclusters material comprises a pyrazole-based porous organic polymer and ruthenium nanoclusters supported on the pyrazole-based porous organic polymer, wherein the pyrazole-based porous organic polymer exhibits a nanowire morphology and the ruthenium nanoclusters have a particle size of approximately 1 to 3 nm.
[0017] Thirdly, the present invention provides the application of the pyrazole-based porous organic polymer-supported ruthenium nanoclusters in the electrocatalytic hydrogen evolution reaction.
[0018] The specific method of the application is as follows: the electrochemical test adopts a typical three-electrode system, wherein the working electrode is an L-shaped glassy carbon electrode loaded with Ru@Pz-POP, the reference electrode is an Hg / HgO electrode, and the counter electrode is a graphite rod.
[0019] Furthermore, the loading of Ru@Pz-POP on the glassy carbon electrode was 0.2–1 mg / cm³. 2 The electrolyte is a 1 M KOH aqueous solution.
[0020] This invention has at least one of the following beneficial effects: (1) This invention develops a method for confining and synthesizing highly dispersed ruthenium nanoclusters using porous organic polymers without the need for any surfactants or modifiers. This method also has the advantages of mild and controllable reaction conditions, simple process flow, and high reproducibility.
[0021] (2) The present invention can prepare ruthenium nanoclusters with an average particle size of only 2.5 nm.
[0022] (3) The catalyst prepared by this invention has good electrocatalytic hydrogen evolution activity, and only an overpotential of 8 mV is required to obtain 10 mA / cm 2 The current density. Attached Figure Description
[0023] Figure 1 This is the X-ray powder diffraction pattern of the Pz-POP of the present invention.
[0024] Figure 2 This is a scanning electron microscope image of the Pz-POP of the present invention.
[0025] Figure 3 This is a transmission electron microscope image of the Pz-POP of the present invention.
[0026] Figure 4 This is the X-ray powder diffraction pattern of Ru@Pz-POP of the present invention.
[0027] Figure 5 This is a scanning electron microscope image of the Ru@Pz-POP of the present invention.
[0028] Figure 6 This is a transmission electron microscope image of the Ru@Pz-POP of the present invention.
[0029] Figure 7 This is a linear sweep voltammetry curve of the Ru@Pz-POP of the present invention.
[0030] Figure 8 This is the electrochemical impedance spectroscopy of Ru@Pz-POP of the present invention.
[0031] Figure 9 This is a graph showing the electrochemical stability of Ru@Pz-POP of the present invention. Detailed Implementation
[0032] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0033] Example 1: Preparation of pyrazole-based porous organic polymers This embodiment provides a method for preparing a pyrazole-based porous organic polymer (Pz-POP), comprising the following steps: 2,4,6-Tricarboxymethyl phloroglucinol (1 mmol) and 1H-pyrazole-3,5-diamine (1.5 mmol) were placed in a pressure-resistant tube, dissolved in 4.5 mL of 1,4-dioxane, and then 4.5 mL of mesitylene was added. The mixture was sonicated for 30 min, followed by the addition of 1.5 mL of 3 mol·L⁻¹ solution. 1 The tube was then rapidly frozen in a liquid nitrogen bath for 30 hours and sealed. It was then placed in a constant temperature oven at 120°C for 3 days. After cooling, it was centrifuged, washed with acetone, and dried to obtain the pyrazole-based porous organic polymer (Pz-POP).
[0034] The X-ray diffraction pattern of the product obtained in this embodiment is shown in the figure. Figure 1 Scanning electron microscope image (see) Figure 2 The transmission electron microscope image is shown below. Figure 3 ; Figures 1-3 The successful preparation of Pz-POP was demonstrated, and the synthesized Pz-POP material exhibited a nanowire morphology.
[0035] Example 2: Preparation of ruthenium nanoclusters supported on pyrazole-based porous organic polymers This embodiment provides a method for preparing ruthenium nanoclusters supported on pyrazole-based porous organic polymers (Ru@Pz-POP), comprising the following steps: 50 mg of Pz-POP prepared in Example 1 was dispersed in 5 mL of deionized water and ultrasonically dispersed for 20 min. RuCl3 was then added to achieve a solubility of 0.02 mol·L⁻¹. 1 The mixture was stirred at room temperature for 12 h. Then, 1 mL of sodium borohydride aqueous solution (1M) was added dropwise, and stirring was continued for 2 h. The mixture was centrifuged, washed with water and ethanol, and dried to obtain pyrazole-based porous organic polymer-supported ruthenium nanoclusters (Ru@Pz-POP).
[0036] The X-ray diffraction pattern of the product Ru@Pz-POP obtained in this embodiment is shown in the figure. Figure 4 Scanning electron microscope image (see) Figure 5 The transmission electron microscope image is shown below. Figure 6 ; Figures 4-6 The successful preparation of Ru@Pz-POP was demonstrated. The Pz-POP material exhibits a nanowire morphology, with ruthenium (Ru) nanoclusters loaded on the Pz-POP. The particle size of the Ru nanoclusters is approximately 2.5 nm.
[0037] Example 3 Electrocatalytic HER performance test of Ru@Pz-POP The electrocatalytic HER performance of Ru@Pz-POP prepared in Example 2 was tested using the following method: The electrocatalytic HER performance of the Ru@Pz-POP material obtained in Example 2 was tested using a typical three-electrode system on a CHI760E electrochemical workstation. The electrolyte was a 1 M KOH aqueous solution. Hg / HgO and a graphite rod were used as the reference and counter electrodes, respectively. Working electrode preparation: 2 mg of the catalyst Ru@Pz-POP was weighed, and 1 mg of carbon black, 150 µL of isopropanol, and 30 µL of Nafion solution were added. The mixture was ultrasonically dispersed to prepare a catalyst ink. 10 µL of the catalyst ink was uniformly coated onto a 5 mm L-shaped glassy carbon electrode and allowed to dry at room temperature to form a uniform thin film, thus preparing the working electrode.
[0038] In comparison, elemental Ru and the commercial catalyst Pt / C were tested for their electrocatalytic HER performance using the same method described above.
[0039] Figure 7 The figure shows the linear sweep voltammetry curve. Ru@Pz-POP only requires an 8 mV overpotential to achieve 10 mA / cm². 2 Its current density is superior to that of elemental Ru and the commercial catalyst Pt / C.
[0040] Figure 8 The electrochemical impedance spectroscopy (EIS) shows that Ru@Pz-POP exhibits the best conductivity compared to elemental Ru and the commercial catalyst Pt / C.
[0041] Figure 9 The image shows the electrochemical stability test results; Ru@Pz-POP can achieve a stability of 1 A / cm. 2 It operates stably for 100 hours under high current density, demonstrating good electrochemical durability.
[0042] In summary, the Pz-POP material prepared by this invention exhibits excellent electrocatalytic hydrogen evolution reaction performance and has potential application prospects in electrocatalytic hydrogen evolution.
[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A method for preparing ruthenium nanoclusters supported on a pyrazole-based porous organic polymer, characterized in that, Includes the following steps: S1. A pyrazole-based porous organic polymer was prepared by polycondensation of 2,4,6-tricarboxymethyl phloroglucinol and 1H-pyrazole-3,5-diamine. S2. The pyrazole-based porous organic polymer and ruthenium salt are mixed, and a reducing agent is added to prepare ruthenium nanoclusters supported on the pyrazole-based porous organic polymer.
2. The preparation method according to claim 1, characterized in that, Step S1 includes the following specific steps: 2,4,6-tricarboxymethyl phloroglucinol and 1H-pyrazole-3,5-diamine were placed in a pressure-resistant tube, and 1,4-dioxane and mesitylene were added and mixed evenly. Then, acetic acid solution was added and mixed evenly. The pressure-resistant tube was frozen and sealed, and then placed in a constant temperature oven for reaction to obtain the pyrazole-based porous organic polymer-supported ruthenium nanoclusters material.
3. The preparation method according to claim 2, characterized in that, The molar ratio of 2,4,6-tricarboxymethyl phloroglucinol and 1H-pyrazole-3,5-diamine is 2:3; the volume ratio of 1,4-dioxane, mesitylene, and acetic acid solution is 3:3:1; and the concentration of acetic acid solution is 3–6 mol·L⁻¹. 1 .
4. The preparation method according to claim 2, characterized in that, The freezing method involves freezing in liquid nitrogen for 25-35 hours. The reaction temperature is 100~160℃, and the reaction time is 2~5 days.
5. The preparation method according to claim 2, characterized in that, Step S2 includes the following specific steps: The pyrazol-based porous organic polymer was dispersed in water, and ruthenium salt was added and mixed for 10-14 hours to obtain a mixture. A reducing agent was added to the mixture, and the mixture was mixed for 1-3 hours. The product was obtained by centrifugation, and the product was washed and dried to prepare pyrazole-based porous organic polymer-supported ruthenium nanoclusters.
6. The preparation method according to claim 5, characterized in that, In step S2, the ruthenium salt includes at least one of ruthenium chloride, sulfate, nitrate, acetate, and salt hydrate; the concentration of the ruthenium salt in the mixture is 0.01~0.03 mol·L⁻¹. 1 The molar ratio of the pyrazole-based porous organic polymer to the ruthenium salt is 1~3:
1.
7. The preparation method according to claim 5, characterized in that, In step S2, the reducing agent is a borohydride, which is at least one of sodium borohydride and potassium borohydride, and the molar ratio of the borohydride to the ruthenium salt is 5~20:
1.
8. A pyrazole-based porous organic polymer-supported ruthenium nanoclusters material, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 7.
9. The pyrazole-based porous organic polymer-supported ruthenium nanoclusters according to claim 8, characterized in that, The pyrazole-based porous organic polymer-supported ruthenium nanoclusters material includes a pyrazole-based porous organic polymer and ruthenium nanoclusters supported on the pyrazole-based porous organic polymer. The pyrazole-based porous organic polymer exhibits a nanowire morphology, and the ruthenium nanoclusters have a particle size of approximately 1 to 3 nm.
10. The application of the pyrazole-based porous organic polymer-supported ruthenium nanoclusters according to any one of claims 8 to 9 in the electrocatalytic hydrogen evolution reaction.