A nickel-based anode catalyst, a preparation method and application thereof

Abstract

The application belongs to the technical field of biomass electrochemical catalytic value-added technology, and discloses a nickel-based anode catalyst as well as a preparation method and application thereof, which comprises the following steps: (1) dissolving nickel salt, iron salt, zinc salt, urea and ammonium fluoride in water to obtain a reaction solution, and immersing foamed nickel in the reaction solution to perform a hydrothermal reaction, so as to obtain a nickel-based precursor material; (2) immersing the nickel-based precursor material in a strong alkali solution to perform etching, so as to obtain a nickel-based precursor material containing cation vacancies; and (3) mixing the nickel-based precursor material containing cation vacancies obtained in the step (2) with a phosphorus source, and then performing calcination, so as to obtain the nickel-based anode catalyst. The electronic structure of the catalyst is optimized, and the adsorption capacity of the catalyst for a lignin model compound is improved. When the catalyst is applied to electrolysis of the lignin model compound as an anode, the catalyst exhibits excellent catalytic activity under specific constant potential conditions, and can selectively prepare high-value aromatic compounds.

Description

Technical Field

[0001] This invention belongs to the field of biomass resource utilization and relates to a method for preparing a nickel-based anodic electrocatalyst containing cation vacancies and a highly selective oxidative conversion method for lignin model compounds. Background Technology

[0002] Lignin, as an abundant renewable resource, is the only non-fossil raw material in nature that can provide a large quantity of aromatic compounds. However, its highly complex chemical structure makes degradation difficult. Traditional methods for studying the cleavage of lignin's C / C bonds include chemical oxidation, hydrogenolysis and reduction, biological methods, and thermal pyrolysis. However, these methods all have several drawbacks that need to be overcome, such as requiring harsh high-temperature conditions, high-pressure hydrogen or oxygen, lacking good economic efficiency, and posing a risk of environmental pollution.

[0003] Electrochemical catalysis offers advantages such as milder reaction conditions, alignment with green environmental protection principles, low cost, and more controllable reaction parameters, making the electrocatalytic depolymerization of lignin a subject of great interest. In recent years, metal oxidation catalysts have been frequently reported, with common metal catalysts including Ru, Pt, Pd, and Rh. Compared to precious metals, transition metal nickel (Ni) offers advantages such as high economic efficiency, material stability and durability, and high conductivity, exhibiting excellent performance in many electrochemical catalytic processes, such as water electrolysis. Furthermore, Ni possesses a high sequence of 3d electrons, and its chemical properties and catalytic performance can be modulated through different alloying, doping, support materials, and surface modifications, thereby achieving precise control and optimization of catalytic reactions and improving electrocatalytic activity. Currently, nickel-based catalysts such as nickel hydroxide (Ni(OH)2) show potential in the electrooxidation reactions of various biomass-derived molecules, such as ethylene glycol, glycerol, 5-hydroxymethylfurfural, and furfural. However, due to the high dissociation energy of lignin's C-C bonds and the relatively weak adsorption capacity of lignin and its model compounds on the surface of nickel hydroxide electrocatalysts, current methods still struggle to achieve highly selective and high-yield electrochemical catalytic cleavage of C-C bonds. Existing NiOOH / NF and NiFeC@NF catalysts, while yielding good aromatic acids and aldehydes during the depolymerization of β-O-4 binary model compounds, exhibit low yields of phenolic products, resulting in a low overall monomer yield. Furthermore, the preparation conditions for traditional transition metal oxide catalysts are demanding, requiring calcination in a H2 atmosphere or at 800°C, and the materials exhibit inhomogeneous morphology and limited specific surface area. Summary of the Invention

[0004] The purpose of this invention is to provide a NiFeP / NF electrocatalyst containing cation vacancies, its preparation method, and its application, which can achieve precise cleavage of lignin C-C bonds and improve the selectivity and yield of electrochemical oxidative depolymerization of lignin.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A method for preparing a nickel-based anode catalyst includes the following steps:

[0007] (1) Nickel salt, iron salt, zinc salt, urea and ammonium fluoride are dissolved in water to obtain a reaction solution, and nickel foam is immersed in the reaction solution to carry out a hydrothermal reaction to obtain the nickel-based precursor material NiFeZn / NF;

[0008] (2) The nickel-based precursor material from step (1) is immersed in a strong alkaline solution for etching to obtain a nickel-based precursor material Ni containing cation vacancies. vac Fe / NF;

[0009] (3) The nickel-based precursor material containing cation vacancies obtained in step (2) is mixed with a phosphorus source and then calcined to obtain a nickel-based anode catalyst Ni with a three-dimensional flower-shaped hierarchical structure. vac FeP / NF.

[0010] Preferably, the molar ratio of nickel salt, iron salt, zinc salt, urea and ammonium fluoride in step (1) is 1: (0.3-2): (0.02-0.2): (5-20): (2-10).

[0011] Preferably, the iron salt in step (1) is one or more of ferric chloride and ferric nitrate; the nickel salt is one or more of nickel nitrate, nickel acetate, and nickel chloride; the zinc salt is one or more of zinc nitrate, zinc chloride, and zinc sulfate; and the phosphorus source is NaH2PO2, Na2HPO3, H3PO3, H3PO4, Na3PO4, (NH4)2HPO4, NH4H2PO4, Na4P2O7, and Na5P3O7. 10 One or more of them.

[0012] Preferably, the temperature of the hydrothermal reaction in step (1) is 150-200℃ and the time of the hydrothermal reaction is 10-20h.

[0013] Preferably, the strong alkali solution in step (2) is one or both of KOH and NaOH solutions, and the concentration of the strong alkali solution is 1-10 mol / L. -1 The etching time is 2-8 hours and the temperature is 20-80℃.

[0014] Preferably, step (3) is carried out in an oxygen-free environment, with the mass ratio of phosphorus source to nickel-based precursor material containing cation vacancies being (2-10):1, the calcination temperature being 250-400℃, and the time being 2-4h.

[0015] The nickel-based anode catalyst prepared by the above method is used in the electrocatalytic oxidation of lignin model compounds to prepare aromatic compounds. In an H-type electrolytic cell containing a proton exchange membrane, a three-electrode system is used to electrolyze lignin dimer model compounds at a constant potential to obtain aromatic compounds. The process includes the following steps:

[0016] (1) Assemble a proton exchange membrane electrolyzer, wherein the proton exchange membrane electrolyzer includes an anode, a cathode, a proton exchange membrane, an anode electrolyte and a cathode electrolyte, wherein the anode is a nickel-based anode catalyst;

[0017] (2) The lignin model compound containing β-O-4 bond was added to the anolyte and electro-oxidized at a constant potential of 1.4-1.5V for 4-6h to obtain the aromatic compound.

[0018] Preferably, the cathode is a graphite rod electrode; the reference electrode is an Hg / HgO electrode; both the anode electrolyte and the cathode electrolyte are mixed solutions of KOH and acetonitrile; the concentration of the KOH solution is 0.5-1 mol / L. -1 Acetonitrile accounts for 0.1-0.3% of the total volume.

[0019] Preferably, the lignin dimer model compound includes one or more of 2-phenoxy-1-phenylethanol, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-phenoxyacetophenone, and 2-phenoxy-1-phenylethane; the concentration of the lignin dimer model compound is 5-50 mmol / L. -1 The constant potential voltage is 1.45V, and the electro-oxidation time is 5±0.5h.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention synthesizes a non-noble metal anode catalyst material by in-situ growth method. Among many noble metal and transition metal catalysts, compared with the Pt, Au, Pd and Co system, this electrode material is inexpensive and has a simple and convenient preparation method.

[0022] (2) The present invention uses hydrothermal method and calcination phosphating technology, and the calcination temperature is reduced to 250-400℃, which is simpler, safer and more energy-efficient.

[0023] (3) The Ni of the present invention vac FeP / NF electrocatalysts can achieve a phenol yield of 40%, improving the overall monomer yield of the electro-oxidation process.

[0024] (4) By introducing metal cation vacancies, the present invention optimizes the electronic structure of nickel sites through the synergistic effect of cation vacancies and phosphating, thereby improving the performance of Ni in the electrocatalytic process. 2+ Oxidation to generate high-valence Ni3+ The ability, while high-valence Ni 3+ In electrocatalysis, it is usually an active species; after phosphating, it generates metal phosphides, which optimizes the electronic structure of the catalyst and improves the catalyst's adsorption capacity for lignin model compounds.

[0025] (5) Ni containing cation vacancies vac The electro-oxidation effect of FeP / NF electrocatalyst can break the β-O-4 bond in lignin model compounds. At the same time, the reaction has excellent selectivity, breaking only the C-C bond in the β-O-4 bond, and selectively generating high-value aromatic compounds such as phenol and benzoic acid, with a substrate conversion rate of about 90%. Attached Figure Description

[0026] Figure 1 Ni in Example 1 vac Scanning electron microscope image of FeP / NF electrocatalytic material.

[0027] Figure 2 Ni in Comparative Example 1 vac Scanning electron microscope image of Fe / NF electrocatalytic material.

[0028] Figure 3 Ni in Example 1 vac FeP / NF electrocatalytic material, Ni in Comparative Example 1 vac X-ray diffraction patterns of Fe / NF electrocatalytic materials and NiFe / NF electrocatalytic materials in Comparative Example 2.

[0029] Figure 4 Ni in Example 1 vac X-ray electron spectra of the 2p orbitals of Ni element in FeP / NF electrocatalytic materials and NiFe / NF electrocatalytic materials in Comparative Example 2.

[0030] Figure 5 These are the linear voltammetric scanning polarization curves of Examples 2 and 3 and Comparative Examples 3 and 4.

[0031] Figure 6 This is a chromatogram of the gas chromatography-mass spectrometry analysis results of the system after the constant potential electro-oxidation reaction in Example 2, detected using a flame hydrogen detector.

[0032] Figure 7 This is a chromatogram of the gas chromatography-mass spectrometry analysis results of the system after the constant potential electro-oxidation reaction of Comparative Example 3, with detection performed using a flame hydrogen detector. Detailed Implementation

[0033] To better understand the present invention, the following embodiments are provided for further explanation, but the implementation of the present invention is not limited thereto.

[0034] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0035] Example 1

[0036] A Ni containing cation vacancies vac The preparation method of FeP / NF electrocatalyst includes the following steps:

[0037] (1) Cut the nickel foam (NF) into appropriate sizes, and clean it with acetone, hydrochloric acid, deionized water and ethanol in sequence for 15 min each, and then vacuum dry it at 60℃ for use.

[0038] (2) Dissolve 2 mmol Ni(NO3)2⋅6H2O, 0.9 mmol Fe(NO3)3⋅9H2O, 0.1 mmol Zn(NO3)2⋅6H2O, 20 mmol urea, and 10 mmol NH4F in 80 mL of deionized water and stir to form a homogeneous solution. Transfer the mixed solution to a 100 mL polytetrafluoroethylene-lined stainless steel reactor and immerse the pretreated NF in it. Perform hydrothermal treatment at 180 °C for 12 hours. After cooling to room temperature, wash three times alternately with ethanol and deionized water, and dry overnight at 60 °C to obtain NiFeZn / NF material.

[0039] (3) Place NiFeZn / NF in 6M KOH solution, soak at 60℃ for 3h, and wash several times with deionized water and anhydrous ethanol to remove Zn. 2+ To construct cation vacancies, the above steps were repeated three times, and the mixture was dried overnight at 60°C to obtain Ni containing cation vacancies. vac Fe / NF materials.

[0040] (4) Mix 1.0g of phosphorus source NaH2PO2 and 0.2g of Ni vac Fe / NF material was placed upstream and downstream of a quartz tube and calcined to 320°C for 2 hours under a nitrogen atmosphere at a heating rate of 2°C / min to obtain phosphated Ni. vac FeP / NF catalyst.

[0041] Comparative Example 1

[0042] A Ni containing cation vacancies vac The preparation method of the Fe / NF catalyst includes the following steps:

[0043] (1) Cut the nickel foam (NF) into appropriate sizes, and clean it with acetone, hydrochloric acid, deionized water and ethanol in sequence for 15 min each, and then vacuum dry it at 60℃ for use.

[0044] (2) Dissolve 2 mmol Ni(NO3)2⋅6H2O, 0.9 mmol Fe(NO3)3⋅9H2O, 0.1 mmol Zn(NO3)2⋅6H2O, 20 mmol urea, and 10 mmol NH4F in 80 mL of deionized water and stir to form a homogeneous solution. Transfer the mixed solution to a 100 mL polytetrafluoroethylene-lined stainless steel reactor and immerse the pretreated NF in it. Perform hydrothermal treatment at 180 °C for 12 hours. After cooling to room temperature, wash three times alternately with ethanol and deionized water, and dry overnight at 60 °C to obtain NiFeZn / NF material.

[0045] (3) NiFeZn / NF was placed in 6M KOH solution and soaked at 60℃ for 3 hours, and washed several times with deionized water and anhydrous ethanol. The above steps were repeated 3 times, and the mixture was dried at 60℃ overnight to obtain Ni containing cation vacancies. vac Fe / NF materials.

[0046] Comparative Example 2

[0047] A NiFe / NF catalyst, the preparation method of which includes the following steps:

[0048] (1) Cut the nickel foam (NF) into appropriate sizes, and clean it with acetone, hydrochloric acid, deionized water and ethanol in sequence for 15 min each, and then vacuum dry it at 60℃ for use.

[0049] (2) Dissolve 2 mmol Ni(NO3)2⋅6H2O, 1 mmol Fe(NO3)3⋅9H2O, 20 mmol urea, and 10 mmol NH4F in 80 mL of deionized water and stir to form a homogeneous solution. Transfer the mixed solution to a 100 mL polytetrafluoroethylene-lined stainless steel reactor and immerse the pretreated NF in it. Perform hydrothermal treatment at 180 °C for 12 hours. After cooling to room temperature, wash three times alternately with ethanol and deionized water, and dry overnight at 60 °C to obtain NiFe / NF material.

[0050] The catalyst materials prepared in Example 1 and Comparative Example 1 were subjected to scanning electron microscopy to observe their morphology. The results are as follows: Figure 1 , 2As shown in the figure, the catalyst materials grown in situ on nickel foam all exhibit a three-dimensional flower-shaped array structure composed of self-assembled ultrathin nanosheets, with individual microspheres having a diameter of approximately several micrometers. Furthermore, it was found that the calcination phosphating process does not significantly damage this morphology. Maintaining this unique hierarchical morphology not only reduces stacking to prevent the active sites from being masked, but also ensures rapid electrolyte penetration and efficient mass transfer of reactants.

[0051] X-ray diffraction tests were performed on the catalyst materials prepared in Example 1 and Comparative Example 1. The results are as follows: Figure 3 As shown. The results show that, excluding the diffraction peaks of nickel foam (PDF#04-0850), Ni vac The diffraction peaks of the Fe / NF catalyst match those of NiFe-LDH (PDF#40-0215), indicating that strong alkaline etching does not cause significant changes in the material's crystal phase. Meanwhile, Ni... vac The diffraction peaks of the FeP / NF catalyst are consistent with those of Ni2P (PDF#03-0953), indicating that the crystal phase changes before and after phosphating and calcination, and new phosphides are generated.

[0052] X-ray photoelectron spectroscopy (XPS) was performed on the catalyst materials prepared in Example 1 and Comparative Example 2. The results of the Ni 2p fine spectrum are as follows: Figure 4 As shown in the figure. The results show that the peaks at 875.0 eV and 857.2 eV correspond to Ni 2p. 1 / 2 and Ni2p 3 / 2 The peaks at 880.8 eV and 862.9 eV correspond to satellite peaks, while the peaks at 853.6 eV and 870.8 eV can be attributed to Ni-P species in Ni₂P. Compared to NiFe / NF, the Ni 2p peaks in the catalyst materials are shifted towards higher binding energies. This is due to the presence of numerous cation vacancies, which increase the valence state of surrounding metal ions to maintain charge balance. Furthermore, phosphating introduces P, leading to electron transfer from Ni to P, which in turn shifts the Ni 2p peak towards higher binding energies.

[0053] Example 2

[0054] A method for preparing aromatic compounds by electrocatalytic oxidation of lignin model compounds includes the following steps:

[0055] Using a CHI660E electrochemical workstation, lignin dimer model compounds were subjected to constant-potential electrolysis in an H-type electrolytic cell containing a proton exchange membrane, yielding aromatic compounds. The Ni from Example 1 was used as an example. vac FeP / NF electrocatalyst (1*1cm) 2The electrode is the working anode, the graphite rod is the counter cathode, and the Hg / HgO (1M KOH solution) electrode is the reference electrode. Both the anolyte and catholyte are 20 mL mixed solutions of KOH and acetonitrile, with a KOH concentration of 1 mol / L. -1 Acetonitrile constitutes 1 / 5 of the total volume. The lignin model compound 2-phenoxy-1-phenylethanol is dissolved in the anolyte at a concentration of 10 mmol / L. -1 The system was subjected to constant potential electro-oxidation at 1.45 V (vs. RHE) for 5 h using chronoamperometry. After the reaction, the solution was acidified to pH 2-3 with 1 M hydrochloric acid, followed by extraction with ethyl acetate. 100 μL of dimethyl phthalate (5% wt.) was added to the extract organic phase as an internal standard. The product was detected and quantified by gas chromatography-mass spectrometry (GC-MS). The conversion rate and product yield are shown in Table 1. The GC-MS analysis results are as follows: Figure 6 As shown.

[0056] Comparative Example 3

[0057] The difference from Example 2 is that the anode Ni vac The FeP / NF catalyst was replaced with nickel foam, while all other structures remained identical. The conversion and product yields are shown in Table 1. Gas chromatography-mass spectrometry analysis results are as follows: Figure 7 As shown.

[0058] Comparative Example 4

[0059] The difference from Example 2 is that the anolyte does not contain the lignin model compound, but the other structures are exactly the same, and only the linear sweep voltammetry test is performed.

[0060] Comparative Example 5

[0061] The difference from Example 3 is that the anolyte does not contain the lignin model compound, but the other structures are exactly the same, and only the linear sweep voltammetry test is performed.

[0062] The performance of the proton exchange membrane electrolyzer systems prepared in Examples 2 and Comparative Examples 3-5 was tested using linear sweep voltammetry. The scan rate was 2 mV / s within a potential range of 1.0-1.7 V relative to the reversible hydrogen electrode (vs. RHE). Comparisons were made between the addition of the lignin model compound and the addition of the lignin model compound. The polarization curves are shown below. Figure 5 As shown. The potential is adjusted to RHE by the following equation: E(RHE) = E(Hg / HgO) + 0.059 × pH + 0.098 V.

[0063] The results are as follows Figure 5 As shown, without the addition of the lignin model compound, Ni vacThe FeP / NF electrode exhibits an oxidation peak at 1.35V (vs. RHE), which corresponds to Ni. 2+ Under the influence of electric potential, it is oxidized to form Ni with a higher valence state. 3+ The conversion process, with a sharp increase in current after the potential exceeds 1.45V, can be attributed to the OER reaction. After adding 10 mM of the lignin model compound, Ni... vac The current density of FeP / NF continued to rise rapidly after 1.35V, and the oxidation current was even greater at the same potential, indicating that Ni... vac FeP / NF electrocatalytic materials exhibit higher activity and better catalytic effect for the oxidation of lignin model compounds. In contrast, pure nickel foam electrodes do not show a significant oxidation peak at 1.35V, have a lower oxidation current density, and do not show significant catalytic activity for lignin model compounds.

[0064] Example 3

[0065] The difference from Example 2 is that the constant potential oxidation voltage was replaced from 1.45V to 1.4V. The other structures are exactly the same. The conversion rate and product yield are shown in Table 2.

[0066] Example 4

[0067] The difference from Example 2 is that the constant potential oxidation voltage was replaced from 1.45V to 1.5V. The other structures are exactly the same. The conversion rate and product yield are shown in Table 2.

[0068] Comparative Example 6

[0069] The difference from Example 2 is that the anode Ni vac The FeP / NF catalyst was replaced with Ni containing cation vacancies prepared in Comparative Example 1. vac The Fe / NF catalysts have identical structures in all other respects. The conversion and product yields are shown in Table 1.

[0070] Comparative Example 7

[0071] The difference from Example 2 is that the anode Ni vac The FeP / NF catalyst was replaced with the NiFe / NF catalyst prepared in Comparative Example 2, with all other structures being exactly the same. The conversion rate and product yield are shown in Table 1.

[0072] Comparative Example 8

[0073] The difference from Example 2 is that the constant potential oxidation voltage was replaced from 1.45V to 1.35V. The other structures are exactly the same. The conversion rate and product yield are shown in Table 2.

[0074] Comparative Example 9

[0075] The difference from Example 2 is that the constant potential oxidation voltage was replaced from 1.45V to 1.55V. The other structures are exactly the same. The conversion rate and product yield are shown in Table 2.

[0076] Comparative Example 10

[0077] The difference from Example 2 is that the constant potential oxidation time was changed from 5h to 1h, while the other structures are exactly the same. The conversion rate and product yield are shown in Table 2.

[0078] Comparative Example 11

[0079] The difference from Example 2 is that the constant potential oxidation time was changed from 5h to 3h. The other structures are exactly the same. The conversion rate and product yield are shown in Table 2.

[0080] Comparative Example 12

[0081] The difference from Example 2 is that the constant potential oxidation time was changed from 5h to 7h, while the other structures are exactly the same. The conversion rate and product yield are shown in Table 2.

[0082] Table 1 Evaluation results of electrolysis of 2-phenoxy-1-phenylethanol by different electrode products

[0083]

[0084] The results of Example 2 show that the cleavage of the β-O-4 bond in the lignin model compound yields benzoic acid and phenol, and the electro-oxidation process exhibits high selectivity for C-C bond cleavage. Compared to pure nickel foam, Ni... vac The FeP / NF electrocatalytic material exhibited significantly improved conversion and yield, demonstrating excellent catalytic activity. Meanwhile, results under different electrolysis conditions showed that the yield initially increased and then decreased with increasing voltage and time. This is because excessive voltage and time can lead to product peroxidation.

[0085] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a nickel-based anode catalyst, characterized in that, Includes the following steps: (1) Dissolve nickel salt, iron salt, zinc salt, urea and ammonium fluoride in water to obtain a reaction solution, and then impregnate the nickel foam in the reaction solution to carry out a hydrothermal reaction to obtain a nickel-based precursor material; (2) The nickel-based precursor material in step (1) is immersed in a strong alkaline solution for etching to obtain a nickel-based precursor material containing cation vacancies; (3) The nickel-based precursor material containing cation vacancies obtained in step (2) is mixed with a phosphorus source and then calcined to obtain a nickel-based anode catalyst.

2. The preparation method according to claim 1, characterized in that, The molar ratio of nickel salt, iron salt, zinc salt, urea and ammonium fluoride in step (1) is 1: (0.3-2): (0.02-0.2): (5-20): (2-10).

3. The preparation method according to claim 1, characterized in that, The iron salt in step (1) is one or more of ferric chloride and ferric nitrate; the nickel salt is one or more of nickel nitrate, nickel acetate, and nickel chloride; the zinc salt is one or more of zinc nitrate, zinc chloride, and zinc sulfate; and the phosphorus source is NaH2PO2, Na2HPO3, H3PO3, H3PO4, Na3PO4, (NH4)2HPO4, NH4H2PO4, Na4P2O7, and Na5P3O. 10 One or more of them.

4. The preparation method according to claim 1, 2, or 3, characterized in that, The temperature of the hydrothermal reaction in step (1) is 150-200℃, and the reaction time is 10-20h.

5. The preparation method according to claim 1, 2, or 3, characterized in that, The strong alkali solution mentioned in step (2) is one or both of KOH and NaOH solutions, and the concentration of the strong alkali solution is 1-10 mol / L. -1 The etching time is 2-8 hours and the temperature is 20-80℃.

6. The preparation method according to claim 1, 2, or 3, characterized in that, Step (3) is carried out in an oxygen-free environment, with the mass ratio of phosphorus source to nickel-based precursor material containing cation vacancies being (2-10):1, the calcination temperature being 250-400℃, and the time being 2-4h.

7. The nickel-based anode catalyst prepared by the method according to any one of claims 1 to 6.

8. The application of the nickel-based anode catalyst according to claim 7 in the electrocatalytic oxidation of lignin model compounds to prepare aromatic compounds, characterized in that, Includes the following steps: (1) Assemble a proton exchange membrane electrolyzer, wherein the proton exchange membrane electrolyzer includes an anode, a cathode, a proton exchange membrane, an anode electrolyte and a cathode electrolyte, wherein the anode is a nickel-based anode catalyst; (2) The lignin model compound containing β-O-4 bond was added to the anolyte and electro-oxidized for 4-6 h under a constant potential of 1.4-1.5 V to depolymerize the aromatic compound.

9. The method according to claim 8, characterized in that, The cathode is a graphite rod electrode; the reference electrode is a Hg / HgO electrode; both the anode electrolyte and the cathode electrolyte are mixed solutions of KOH and acetonitrile; the concentration of the KOH solution is 0.5-1 mol / L. -1 Acetonitrile accounts for 0.1-0.3% of the total volume.

10. The method according to claim 9, characterized in that, The lignin dimer model compound includes one or more of 2-phenoxy-1-phenylethanol, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-phenoxyacetophenone, and 2-phenoxy-1-phenylethane; the concentration of the lignin dimer model compound is 5-50 mmol / L. -1 The constant potential voltage is 1.45V, and the electro-oxidation time is 5±0.5h.

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