Precious metal ruthenium monatomic supported catalyst as well as preparation method and application thereof

Abstract

The invention relates to the field of catalysts, and particularly discloses a noble metal ruthenium monatomic supported catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: S1, pretreatment of foamed nickel: sequentially cleaning the foamed nickel NF with a mixed solution of an HCl solution, water and ethanol to obtain pretreated foamed nickel; s2, preparation of an electrocatalyst Ru-NiMn / NF-IH: a, mixing NiSO4. 6H2O, MnCl2. 6H2O and RuCl3. XH2O, dissolving the mixture in water to form a transparent solution, adding urea, and uniformly stirring to obtain a mixed solution A; and b, flatly putting the pretreated foamed nickel obtained in the step S1 into the mixed solution A, and carrying out induction heating. The electrocatalyst can be simultaneously used for preparing high-value FDCA through selective electrocatalytic oxidation of HMF and producing hydrogen through electrolysis of water. And the HMOR and the HER have relatively high current density and Faraday efficiency at relatively low potential.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalysts, specifically relating to a method for preparing and applying a highly efficient noble metal ruthenium single atom supported on a nickel-manganese bimetallic hydroxide electrocatalyst. Background Technology

[0002] 5-Hydroxymethylfurfural (HMF) is listed as one of the top ten priority biomass platform chemicals for preparation due to its abundant functional groups (aldehyde, hydroxymethyl, and furan ring, etc.). It can be obtained by removing three molecules of water from cellulose and sugars (such as fructose and glucose). Its oxidation product, FDCA, has a "rigid" planar structure and the multifunctionality of dicarboxylic acid side chains. The biomass-based polymer synthesized from it—polyethylene furanate (PEF)—exhibits good oxygen, carbon dioxide, and water barrier properties, as well as better thermal stability and mechanical properties. Furthermore, its synthesis process is greener than the production of traditional petroleum-based plastic polyethylene terephthalate (PET) (reducing the consumption of non-renewable resources and greenhouse gas emissions by about 50%), and it also has superior performance and no reproductive toxicity, thus becoming an ideal alternative to PET.

[0003] The synthesis of 2,5-furandicarboxylic acid (FDCA) from HMF using thermal, electrochemical, and photocatalytic methods has become an important approach for FDCA production, connecting it to the polymer industry chain. Electrocatalysis, which requires no additional oxidants and operates under low reaction conditions, is gaining widespread application. Simultaneously, cathodic electrochemistry for hydrogen production via water electrolysis can produce value-added chemicals at both the cathode and anode, increasing economic viability. However, the current process route, particularly for FDCA, faces numerous challenges. This is primarily because HMF, possessing hydroxyl, carbonyl, and furan rings, is highly reactive. In the high-alkalinity, high-concentration HMF-to-FDCA production process, it readily undergoes side reactions to generate humic acid. Furthermore, few catalysts can simultaneously be used for HMFOR (5-hydroxymethylfurfural oxidation) and HER (electrocatalytic hydrogen evolution reaction). To achieve efficient coupling of HMF to FDCA and water electrolysis for hydrogen production, it is crucial to construct a highly active, easily prepared, and stable electrocatalyst capable of simultaneously catalyzing HER and HMFOR. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by providing a rapidly prepared bifunctional noble metal ruthenium single-atom supported catalyst, its preparation method, and its application. The catalyst is a nickel-manganese hydroxide supported ruthenium single-atom catalyst (Ru-NiMn / NF-IH).

[0005] The technical problem to be solved by this invention is achieved by the following technical solution:

[0006] A method for preparing a ruthenium single-atom supported catalyst, comprising the following steps:

[0007] S1. Pretreatment of nickel foam: Nickel foam NF was washed sequentially with HCl solution, water and ethanol mixture to obtain pretreated nickel foam;

[0008] S2. Preparation of the electrocatalyst Ru-NiMn / NF-IH:

[0009] a. Mix NiSO4·6H2O, MnCl2·6H2O and RuCl3·xH2O and dissolve them in water to form a transparent solution. Then add urea and stir until homogeneous to obtain mixed solution A.

[0010] b. Place the pretreated nickel foam obtained in step S1 into the mixed solution A and induction heat it to obtain the nickel-manganese hydroxide supported ruthenium single-atom catalyst Ru-NiMn / NF-IH.

[0011] Preferably, nickel foam with high specific surface area, good pore connectivity, and adaptability is selected as the substrate material.

[0012] Preferably, in step S1, the pretreatment of the nickel foam involves cutting the nickel foam NF and washing it in an HCl solution to remove the nickel oxide layer and impurities from the surface. Subsequently, it is washed with deionized water and ethanol to remove any hydrochloric acid solution and residual organic matter from the surface, ultimately obtaining the pretreated nickel foam.

[0013] Preferably, in step S1, the nickel foam is cut into 1.5cm x 2cm pieces, and ultrasonic cleaning is performed sequentially using 1mol / L dilute hydrochloric acid, deionized water, and ethanol.

[0014] Preferably, in step a of S2, nickel and manganese metals, which exhibit excellent activity in the HMFOR reaction and have adsorption properties for the substrate, are selected as the metals loaded on the nickel foam. Ruthenium, a metal that can promote proton transport in the HMFOR reaction, is selected as a modification.

[0015] Specifically, the molar ratio of NiSO4·6H2O, MnCl2·6H2O, and RuCl3·xH2O is 1:0.8-1.2:0.05-0.09, and the amount of water added is 10 mL. 2+ Mn 2+ and Ru 3+ The total molar amount in the solution ranges from 0.463 to 0.575 mmol. The addition of urea promotes the formation of hydroxides, with a specific dosage of 0.04 to 0.08 g. To ensure the solution is homogeneous, stir for 2 to 8 minutes.

[0016] More preferably, the molar ratio of NiSO4·6H2O, MnCl2·6H2O, and RuCl3·xH2O is 1:1:0.07, and the amount of water added is 10 mL. 2+ Mn 2+ and Ru 3+ The total molar amount in the solution was 0.517 mmol, the specific amount of urea used was 0.06 g, and the stirring time was 5 min.

[0017] Preferably, in step b of S2, the pretreated nickel foam is placed flat into the mixed solution A, and the beaker containing the nickel foam and mixed solution A is placed at the center of the induction coil for induction heating. Induction heating is used because it can achieve rapid and uniform heating, avoid local overheating that leads to uneven product morphology, and the non-contact heating reduces the introduction of impurities. It also has high energy utilization and allows for precise control of the reaction temperature. After the induction-heated liquid boils, heating is stopped. After the liquid cools to room temperature, the nickel foam is washed with deionized water, placed in an oven, and dried to obtain ruthenium single-atom supported on the nickel-manganese bimetallic hydroxide catalyst Ru-NiMn / NF-IH.

[0018] Preferably, in step b of S2, the inner diameter of the induction heating coil is 2-5 cm, and the nickel foam and mixed solution A are placed in a beaker with an inner diameter of 1-4 cm; the induction current is 200-400 A, the reaction time is 150-250 s, and the maximum temperature during the reaction is 100 ℃; the treated nickel foam is dried at 50-80 ℃ for 4-8 h; more preferably, the inner diameter of the induction heating coil is 2.2 cm, the inner diameter of the beaker is 1.1 cm, the induction current is 300 A, the reaction time is 200 s, and the treated nickel foam is dried at 60 ℃ for 6 h.

[0019] This invention also provides a nickel-manganese hydroxide-supported ruthenium single-atom catalyst (Ru-NiMn / NF-IH) prepared by the above method. The catalyst is a bifunctional electrocatalyst for the highly efficient electrocatalytic oxidation of 5-hydroxymethylfurfural and the electrolysis of water to produce hydrogen.

[0020] The present invention also provides the application of the above-mentioned nickel-manganese hydroxide supported ruthenium single-atom catalyst (Ru-NiMn / NF-IH).

[0021] Furthermore, it was applied in the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furanoic acid (FDCA) and in the electrolysis of water to produce hydrogen.

[0022] As a preferred method, the application method is as follows:

[0023] A three-electrode electrolysis system was constructed using a nickel-manganese hydroxide-supported ruthenium single-atom catalyst, with KOH as the alkaline electrolyte. For the electrooxidation of HMF to FDCA, a certain concentration of HMF was added to the system as the substrate for the oxidation reaction, and electrolysis was carried out by applying a constant voltage to achieve selective oxidation of HMF to FDCA at the anode. For the cathodic electrolysis of water to produce hydrogen, a three-electrode system was directly constructed and a catalyst was used to perform cathodic electrolysis of water to produce hydrogen.

[0024] As a preferred option, the specific application method is as follows:

[0025] The electrolysis temperature was controlled at room temperature, the concentration of the KOH alkaline electrolyte was 1 mol / L, the initial concentration of HMF was 10-50 mmol / L, the applied electrolysis voltage was 1.4-1.6 V, and the electrolysis time was 3-5 h. During the reaction, the stirring rate of the system was maintained at 200-1400 r / min; the cathode current density was 8-12 mA / cm². 2 ;

[0026] Further optimizations included a KOH alkaline electrolyte concentration of 1 mol / L, an initial HMF concentration of 10 mmol / L, an applied electrolysis voltage of 1.45 V (relative to the reversible hydrogen electrode), an electrolysis time of 4 h, and maintaining a stirring rate of 1200 r / min throughout the reaction. The cathode current density was 10 mA / cm². 2 .

[0027] The beneficial effects of this invention are:

[0028] 1. The Ru-NiMn / NF-IH electrocatalyst prepared on a nickel foam substrate in this invention has the advantages of selectively preparing high-value FDCA by electrooxidation of high-concentration HMF in 1 mol / L KOH, maintaining a stable FDCA yield and Faradaic efficiency in 12 consecutive electrolysis cycles, and can also be used as an electrocatalyst for hydrogen production by cathodic electrolysis of water with a stability of over 100 h.

[0029] 2. In this invention, a Ru-NiMn / NF-IH electrocatalyst was synthesized via a rapid and simple induction thermal method. The Ru-NiMn / NF-IH with optimal performance was screened by changing the metal type and concentration in the starting solution. The Ru-NiMn / NF-IH exhibits a wrinkled nanosheet structure, and its current density for oxidizing HMF reaches 120 mA / cm² at a voltage of 1.45 V vs RHE. 2 The yield and Faraday efficiency of FDCA were both greater than 95% over 12 consecutive cycles. For the hydrogen production reaction via water electrolysis at the cathode, a yield of 10 mA / cm² was achieved. 2The required current density is only -0.07 V vs RHE, and the stability exceeds 100 h. This bifunctional catalyst exhibits superior catalytic activity compared to most reported nickel-based catalysts.

[0030] 3. Characterization results of this invention demonstrate that the introduction of Mn and Ru promotes the formation of high-valence Ni species in HMFOR and enhances the yield of FDCA by altering the reaction pathway of HMF. This invention prepares a cost-effective nickel-manganese hydroxide-supported ruthenium single-atom electrocatalyst, exhibiting excellent efficiency and stability in the preparation of FDCA from HMFOR and the electrolysis of water for hydrogen production. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 Schematic diagram and morphological structure diagram of the preparation of Ru-NiMn / NF-IH catalyst;

[0033] Figure 2 Electronic structure characterization diagrams of Ni / NF-IH, NiMn / NF-IH and Ru-NiMn / NF-IH catalysts;

[0034] Figure 3 .HMFOR activity and stability diagrams on Ni / NF-IH, NiMn / NF-IH and Ru-NiMn / NF-IH catalysts;

[0035] Figure 4 Radar graph comparing the HER activity, stability, and activity of Ni / NF-IH, NiMn / NF-IH, and Ru-NiMn / NF-IH catalysts. Detailed Implementation

[0036] To more clearly illustrate the purpose, technical solution, and advantages of this invention, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. The drawings illustrate only exemplary embodiments of the invention and are not intended to limit its implementation. This invention can be implemented in various forms, and its design concept and core technology are not limited to the embodiments shown in the drawings. These embodiments are provided to facilitate understanding of the principles, structure, and function of this invention by those skilled in the art, thereby enabling them to better master and apply its technical solutions. The terminology used in this specification is only for describing specific embodiments and does not constitute a limitation of the invention.

[0037] Example 1. Preparation of Ru-NiMn / NF-IH catalyst

[0038] The aforementioned highly efficient nickel-manganese hydroxide-supported ruthenium single-atom electrocatalyst is specifically an electrocatalyst capable of simultaneously achieving the electrocatalytic oxidation of 5-hydroxymethylfurfural and the electrolysis of water to produce hydrogen.

[0039] The aforementioned method for preparing a highly efficient nickel-manganese hydroxide-supported ruthenium single-atom electrocatalyst includes the following steps:

[0040] S1. Pretreatment of nickel foam:

[0041] After cutting the nickel foam NF into 1.5 cm × 2 cm pieces, it was washed in HCl solution to remove impurities, and then washed with deionized water and ethanol to obtain pretreated nickel foam.

[0042] S2. Preparation of the electrocatalyst Ru-NiMn / NF-IH:

[0043] NiSO4·6H2O, MnCl2·6H2O and RuCl3·xH2O were mixed in a ratio of 1:1:0.07 and dissolved in 10 mL of water to form a transparent solution. Then, 0.06 g of urea was added and stirred until homogeneous to obtain mixed solution one.

[0044] The pretreated nickel foam from S1 was placed flat into the mixed solution one, and the beaker containing the nickel foam and the mixed solution was placed in the center of the induction coil for induction heating under an induction current of 300 A. After the liquid boiled for 200 s, the heating was stopped. After the liquid cooled to room temperature, the nickel foam was washed with deionized water and placed in an oven to dry at 60 ℃ for 6 h to obtain ruthenium single atoms supported on the nickel-manganese bimetallic hydroxide catalyst Ru-NiMn / NF-IH.

[0045] Comparative Example 1. Preparation of Ni / NF-IH Catalyst

[0046] The preparation method of an electrocatalyst Ni / NF-IH is the same as in Example 1, except that MnCl2·6H2O and RuCl3·xH2O are not added in S2.

[0047] Comparative Example 2. Preparation of NiMn / NF-IH Catalyst

[0048] An electrocatalyst NiMn / NF-IH is prepared using the same method as in Example 1, except that RuCl3·xH2O is not added in S2.

[0049] Performance testing:

[0050] (1) Electrochemical performance test of electrocatalytic oxidation of HMF:

[0051] The electrocatalysts obtained in Examples 1, 1, and 2, as well as untreated nickel foam NF, were all cut to a size of 1 × 1.5 cm. Mercury / mercury oxide was used as the reference electrode, a platinum sheet as the counter electrode, and an anion exchange membrane was used to separate the H-type electrolytic cell. Electrolysis was performed in 1 mol / L KOH solution using a KOSTER CS350H electrochemical workstation at a potential range of 1.1–1.65 V vs RHE at 10 mV s⁻¹. -1 Linear sweep voltammetry (LSV) was used to test the performance of water electrolysis. The HMF oxidation performance was also tested by adding 10 mmol / L HMF to a 1 mol / L KOH solution and using the same scan rate. In all LSV tests, iR compensation was not performed. For the cyclic stability testing of HMFOR, a potentiostatic electrolysis test was performed on the HMF-added system. The theoretical HMF charge for FDCA preparation was set, and one electrolysis cycle was completed after reaching this charge. The solution in the electrolytic cell was then reconfigured for the next round of electrolysis, and this process was repeated 12 times.

[0052] (2) Electrochemical performance testing of hydrogen production by electrochemical water electrolysis:

[0053] The electrocatalysts obtained in Examples 1 and 2, as well as untreated nickel foam NF, were all cut to a size of 1×1.5 cm. Mercury / mercury oxide was used as the reference electrode, and a platinum sheet was used as the counter electrode. The performance of hydrogen production from water electrolysis (HER) was tested in 1 mol / L KOH solution using a KOSTER CS350 electrochemical workstation at a linear sweep voltammetry (LSV) rate of 10 mV / s within the potential range of -0.30 to 0 V vs RHE. For the stability testing of HER, a constant current electrolysis method was used, and voltage changes were observed.

[0054] (3) Qualitative and quantitative analysis of oxidation products:

[0055] High-performance liquid chromatography (HPLC) was used for qualitative and quantitative analysis of HMF and its selective oxidation products. The HPLC system was equipped with a UV-Vis detector and an HPX-87H column (column temperature 60 °C). A 5 mM aqueous sulfuric acid solution was used as the mobile phase (flow rate 0.6 mL / min). Specific wavelengths were used to detect different compounds: FDCA and 5-hydroxymethyl-2-furanoic acid (HMFCA) were detected at 260 nm, and 5-formylfuran-2-carboxylic acid (FFCA), 2,5-dicarboxyfuran (DFF), and HMF were detected at 285 nm. Quantitative analysis was performed using the external standard method, and the selectivity, yield, and Faradaic efficiency (FE) of FDCA were determined using equations (1-3).

[0056]

[0057] The experimental results and their analysis are as follows:

[0058] As attached Figure 1 X-ray diffraction as shown in Figure 1 shows that only diffraction peaks corresponding to NF were detected, indicating that the catalyst component grown on the NF substrate surface is amorphous and ultrathin. (See attached figure.) Figure 1 The scanning electron microscope (SEM) shown in dg shows that the prepared Ni / NF-IH, NiMn / NF-IH and Ru-NiMn / NF-IH catalysts are vertically grown as nanosheets on the surface of the NF substrate, and the nanosheets have micron-scale lateral dimensions and nanometer-scale ultrathin thickness.

[0059] As attached Figure 1 As shown in the HAADF-STEM image in Figure h, Ru exists in the form of single atoms. The corresponding energy-dispersive X-ray spectroscopy (EDX) indicates that Ni, Mn, and O elements are uniformly distributed on the Ru-NiMn / NF-IH catalyst nanosheets.

[0060] Table 1. Mass fractions of different metals in the catalyst determined by ICP-MS analysis.

[0061]

[0062] As attached Figure 2 As shown in Figure a, the XPS values ​​of Ni 2p for Ni / NF-IH, NiMn / NF-IH, and Ru-NiMn / NF-IH Ni 2p spectra, with peaks at 855.9 and 873.4 eV, are attributed to Ni 2p. 3 / 2 and Ni 2p 1 / 3 The deconvolution results of Mn 2p showed two main peaks at 640.1 and 642.5 eV, which can be attributed to the Mn on the Ru-NiMn / NF-IH catalyst surface, respectively. 3+ and Mn 4+ 2p of species 3 / 2 Peak (such as) Figure 2 (b) Appendix Figure 2 The peaks at 462.7 eV and 485.2 eV in c correspond to Ru 3p on the surface of the Ru-NiMn / NF-IH catalyst. 3 / 2 and Ru 3p 1 / 2 This demonstrates that the valence state of Ru exists between 0 and +4. Furthermore, X-ray absorption near-edge spectroscopy (XANES) and extended fine structure spectroscopy (EXAFS) further revealed the electronic structure and coordination environment of the catalyst. For the Ru-NiMn / NF-IH catalyst, [further details are needed]. Figure 2The white line intensity of the d-Ru K-edge XANES spectrum is between that of Ru foil and RuO2, indicating that the main valence state of Ru in Ru-NiMn / NF-IH is Ru foil. 0 and Ru 4+ The results are consistent with those obtained by XPS. Wavelet transform results of the EXAFS Fourier transform structure and spectral EXAFS (FT-EXAFS) further confirm the coordination structure information of Ru in Ru-NiMn / NF-IH (see appendix). Figure 2 The two peaks at 1.42 and 2.68 Å in Ru-NiMn / NF-IH correspond to Ru-O and Ru-O-Ni(Mn) bonds, respectively. No Ru-Ru or Ru-Cl signals were observed in the sample, indicating the absence of Ru nanoparticles and residual RuCl3. In summary, Ru in Ru-NiMn / NF-IH is dispersed as single atoms within the Ru-NiMn / NF-IH structure, consistent with the HAADF-STEM results. These results confirm the atomic-level dispersion of Ru and the successful insertion of single-atom Ru into the catalyst via Ru-O bonds.

[0063] Compared to the Ni / NF-IH catalyst, the Ni 2p peak in NiMn / NF-IH and Ru-NiMn / NF-IH catalysts shows positive shifts of 0.1 eV and 0.3 eV, respectively. This indicates electronic interactions between Ni and Mn and Ru metals. X-ray absorption near-edge spectroscopy of Ni and Mn further confirms the electronic interactions between Ru atoms and Ni and Mn. For metallic Ni, compared to Ni / NF-IH, the white line intensity of Ni in NiMn / NF-IH and Ru-NiMn / NF-IH catalysts shows a significant and gradual shift towards higher energy levels (see appendix). Figure 2 (g). This indicates that the introduction of Mn promotes electron loss in Ni, and the introduction of Ru further promotes this phenomenon. For metallic Mn, compared with NiMn / NF-IH, the white line intensity of Mn in Ru-NiMn / NF-IH shifts to the higher energy side but not significantly, which further indicates that electrons are transferred from Mn to Ru (attached). Figure 2 (h). Combined with XPS spectroscopy analysis, it was verified that the electron density on the catalyst surface is perturbed by single-atom Ru and doped metal Mn. Specifically, Ni atoms act as electron donors, transferring electrons through the Ni-O-Mn-O-Ru site.

[0064] As attached Figure 3 As shown in figures a and b, LSV tests were performed on different catalysts in a 1M KOH electrolyte after the introduction of 10 mM HMF. Figure 3HMF substrate was added to b. The results showed that the HMFOR onset potentials of Ni / NF-IH, NiMn / NF-IH, and Ru-NiMn / NF-IH were similar, but the peak current density of Ru-NiMn / NF-IH (119 mA / cm²) was higher. 2 The value was significantly higher than that of NiMn / NF-IH (73 mA / cm). 2 ) and Ni / NF-IH (56 mA / cm 2 This indicates that the introduction of Ru and Mn enhances HMFOR activity (see appendix). Figure 3 (b) with Ni / NF-IH (62 mV dec) -1 ) and NiMn / NF-IH (59 mV dec -1 Compared to Ru-NiMn / NF-IH, the Tafel slope (42 mV dec) -1 The lowest value indicates that the introduction of Ru promotes the reaction kinetics of HMFOR (as shown in Appendix). Figure 3 (e).

[0065] Subsequently, the electrochemical surface area (ECSA) of Ni / NF-IH, NiMn / NF-IH, and Ru-NiMn / NF-IH was analyzed to further investigate the origin of the active sites. (See attached image.) Figure 3 As shown in d, the ECSA of Ni / NF-IH and NiMn / NF-IH catalysts are almost equal, indicating that they have similar amounts of active surface area. Compared with Ni / NF-IH (2.8 mF cm⁻¹), the ECSA of Ni / NF-IH and NiMn / NF-IH catalysts are significantly different. -2 ) and NiMn / NF-IH (2.7 mFcm -2 Compared to Ru-NiMn / NF-IH, the ESCA (3.6 mF cm⁻¹) -2 The increase was slight, indicating that the introduction of Ru is crucial for increasing the specific surface area of ​​the catalyst.

[0066] As attached Figure 3 As shown in Figure c, after the reaction, Ru-NiMn / NF-IH exhibited an optimal conversion rate of 100%, with an FDCA yield of 99.7% and a Faraday efficiency (FE) of 99.9%. In contrast, NiMn / NF-IH and Ni / NF-IH showed FDCA yields of only 93% and 84%, respectively, indicating that Ru-NiMn / NF-IH performs well in HMFOR. Furthermore, Ru-NiMn / NF-IH exhibits excellent stability, maintaining FDCA yield and Faraday efficiency above 95% for 12 consecutive cycles (see Appendix). Figure 3 (f) In this context, its current density and stability are superior to most reported nickel-based oxide catalysts.

[0067] As attached Figure 4 As shown in Figure a, we conducted LSV tests on Ni / NF-IH, NiMn / NF-IH, and Ru-NiMn / NF-IH for hydrogen production via water electrolysis under 1 M KOH conditions. The LSV curves confirmed that the introduction of Ru significantly enhanced the HER activity of Ru-NiMn / NF-IH, with the current density of Ru-NiMn / NF-IH reaching -10 mA / cm² at -0.07 V. 2 Meanwhile, the HER reaction of Ni / NF-IH and NiMn / NF-IH barely started at this time. Activity tests over 150 h showed that Ru-NiMn / NF-IH exhibits good stability in the HER reaction (see appendix). Figure 4 (b). As attached Figure 4 The Tafel slope of c can also be obtained, and the Tafel slope of Ru-NiMn / NF-IH is as low as 75 mV dec. -1 Lower than Ni / NF-IH (232 mV dec) -1 ) and NiMn / NF-IH (248 mV dec -1 This indicates that the HER reaction follows the Volmer-Tafel mechanism, with the chemical recombination of adsorbed hydrogen being the key rate-determining step. (See attached image.) Figure 4 The polarization curves of the HMFOR / / HER dual-electrode catalytic system, using Ru-NiMn / NF-IH as the anode and cathode, confirmed the advantage of HMFOR / / HER in reducing system voltage. (See attached image.) Figure 4 As shown in Figure e, compared to most catalysts currently reported, the catalyst of the present invention exhibits superior stability and activity in the HMFOR and HER reactions.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A method for preparing a ruthenium single-atom supported catalyst, characterized in that, Includes the following steps: S1. Pretreatment of nickel foam: Nickel foam NF was washed sequentially with HCl solution, water and ethanol mixture to obtain pretreated nickel foam; S2. Preparation of the electrocatalyst Ru-NiMn / NF-IH: a. Mix NiSO4·6H2O, MnCl2·6H2O and RuCl3·xH2O and dissolve them in water to form a transparent solution. Then add urea and stir until homogeneous to obtain mixed solution A. b. Place the pretreated nickel foam obtained in step S1 into the mixed solution A and induction heat it to obtain the nickel-manganese hydroxide supported ruthenium single-atom catalyst Ru-NiMn / NF-IH.

2. The preparation method according to claim 1, characterized in that, In step S1, the pretreatment of nickel foam involves cutting the nickel foam NF, ultrasonically cleaning it in HCl solution to remove the nickel oxide layer and impurities on the surface, and then cleaning it with deionized water and ethanol to obtain pretreated nickel foam.

3. The preparation method according to claim 1, characterized in that, In step a of S2, the molar ratio of NiSO4·6H2O, MnCl2·6H2O, and RuCl3·xH2O is 1:0.8-1.2:0.05-0.09, and the amount of water added is 10 mL. 2+ Mn 2+ and Ru 3+ The total molar amount in the solution ranges from 0.463 to 0.575 mmol, the amount of urea added is 0.04 to 0.08 g, and the stirring time is 2 to 8 min.

4. The preparation method according to claim 3, characterized in that, In step a of S2, the molar ratio of NiSO4·6H2O, MnCl2·6H2O, and RuCl3·xH2O is 1:1:0.07, and the amount of water added is 10 mL. 2+ Mn 2 + and Ru 3+ The total molar amount in the solution was 0.517 mmol, the amount of urea added was 0.06 g, and the stirring time was 5 min.

5. The preparation method according to claim 1, characterized in that, In step b of S2, the process involves induction heating to boiling, followed by cooling, washing the treated nickel foam, and drying to obtain the nickel-manganese hydroxide-supported ruthenium single-atom catalyst Ru-NiMn / NF-IH.

6. The preparation method according to claim 5, characterized in that, The inner diameter of the induction heating coil is 2-5 cm. The nickel foam and mixed solution A are placed in a beaker with an inner diameter of 1-4 cm. The induction current is 200-400 A, the reaction time is 150-250 s, and the maximum temperature during the reaction is 100 ℃. The treated nickel foam is dried at 50-80 ℃ for 4-8 h. More preferably, the inner diameter of the induction heating coil is 2.2 cm, the inner diameter of the beaker is 1.1 cm, the induction current is 300 A, the reaction time is 200 s, and the treated nickel foam is dried at 60 ℃ for 6 h.

7. The ruthenium single-atom supported catalyst prepared by any one of claims 1-6.

8. The application of the catalyst of claim 7, characterized in that, It was applied in the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furanoic acid (FDCA) and in the electrolysis of water to produce hydrogen.

9. The application according to claim 8, characterized in that, A three-electrode electrolysis system was constructed using a nickel-manganese hydroxide-supported ruthenium single-atom catalyst, with KOH as the alkaline electrolyte. For the electro-oxidation of HMF to FDCA, HMF was added to the system as the substrate for the oxidation reaction, and electrolysis was carried out by applying a constant voltage to achieve selective oxidation of HMF to FDCA at the anode. For the cathodic electrolysis of water to produce hydrogen, a three-electrode system was directly constructed and a catalyst was used to perform cathodic electrolysis of water to produce hydrogen.

10. The application according to claim 9, characterized in that, The electrolysis temperature was controlled at room temperature, the concentration of the KOH alkaline electrolyte was 1 mol / L, the initial concentration of HMF was 10-50 mmol / L, the applied electrolysis voltage was 1.4-1.6 V, and the electrolysis time was 3-5 h. During the reaction, the stirring rate of the system was maintained at 200-1400 r / min; the cathode current density was 8-12 mA / cm². 2 Further optimizations included: a KOH alkaline electrolyte concentration of 1 mol / L, an initial HMF concentration of 10 mmol / L, an electrolysis voltage of 1.45 V, an electrolysis time of 4 h, a stirring rate of 1200 r / min, and a current density of 10 mA / cm². 2 .

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