A method for the synthesis of a low crystalline layered double hydroxide catalyst for the electrocatalytic oxidation of hmf under low alkalinity conditions

Abstract

The application discloses a synthesis method of a low-crystalline layered double hydroxide catalyst for electrocatalytic oxidation of HMF under low alkalinity conditions. The method comprises the following steps: (1) pretreating a foamed copper to obtain copper oxide nanowires; and (2) uniformly dropping and coating a mixed methanol solution containing high-concentration nickel salt, iron salt and manganese salt on the surface of the copper oxide substrate, and then reacting in a high-concentration alkaline solution by a non-equilibrium precipitation method to obtain the low-crystalline layered double hydroxide catalyst. The catalyst has rich adsorption sites and catalytic active sites, and can promote efficient conversion of HMF under a low alkalinity environment. The conversion rate of 20 mM HMF in 0.1 M KOH electrolyte is 100%, the FDCA selectivity is 93.80%, and the Faraday efficiency is 92.82%. The method effectively solves the problem that HMF is prone to degradation under high alkalinity conditions, and significantly reduces the amount of acid in the subsequent purification process, thereby reducing the production cost.

Description

Technical Field

[0001] This invention relates to a method for synthesizing a low-crystallinity layered double hydroxide catalyst for the electrocatalytic oxidation of HMF under low alkalinity conditions, belonging to the field of chemical engineering. Background Technology

[0002] The rapid consumption of petrochemical resources and the energy and environmental problems arising from their use urgently need to be addressed, making the development of renewable and clean energy imperative. Biomass resources possess advantages such as abundant reserves, renewability, cleanliness, environmental friendliness, and widespread availability. Effective utilization of biomass resources is currently one of the key means to solve energy shortages and environmental pollution. Biomass derivatives 5-hydroxymethylfurfural (HMF) and its oxidation product 2,5-furandicarboxylic acid (FDCA) have been listed by the U.S. Department of Energy as "the most valuable biomass chemicals." According to research and conclusions provided in published literature (Adv. Mater, 2024, 36, 2311464), FDCA not only has high added value but also shares similar properties with petroleum-processed product terephthalic acid, demonstrating significant potential in the market for alternative petrochemicals.

[0003] Electrocatalytic oxidation of HMF provides an environmentally compatible and efficient route for the sustainable synthesis of FDCA. This method is driven by renewable electricity and utilizes water molecules as a green oxygen source in a mild aqueous system to achieve highly selective conversion of HMF. Since the thermodynamic oxidation potential of electrocatalytic HMF is significantly lower than that of the oxygen evolution reaction (OER, with a theoretical onset potential of 1.23 V vs RHE), it can replace the traditional anodic OER, significantly reducing system energy consumption and operating voltage.

[0004] Transition metals are used in electrocatalysis due to their ability to fully exert catalytic activity under potential-driven conditions, and they also have economic advantages. A published paper (Catal. Sci. Technol, 2022, 12(1): 201-211) developed a method using Ni... x Se y A core-shell catalyst with nanowires as the core and NiFe LDH supported on top was developed. The mechanical strength and stability of the NiFe LDH were improved by employing hydrothermal electrodeposition. This method introduces defects into the LDH, providing more active sites for the adsorption and activation of reaction substrates and intermediates, and also increasing the electron density of the metal sites. Simultaneously, Ni... x Se y The interfacial effect between NiFe and LDH resulted in a catalyst exhibiting excellent catalytic performance for the electro-oxidation of HMF, providing 50 mA cm⁻¹ at 1.37 V. -2The method achieves a high HMF conversion efficiency (99.3%) and FDCA yield (99.7%) by adjusting the operating current. However, as with most current research reports, the catalyst prepared by this method only reacts in a strongly alkaline medium. Previous studies (Catal. Sci. Technol., 2021, 11, 4882) have shown that electrolyte alkalinity has a dual impact on reaction performance during the electrocatalytic oxidation of HMF: increasing pH can accelerate the electro-oxidation kinetics of HMF, achieving higher activity and selectivity under strongly alkaline conditions. However, HMF is unstable in strongly alkaline environments and is prone to side reactions such as ring-opening and polymerization, generating humic substances. This not only reduces the yield and selectivity of the target product, but the formed humic substances may also cover the active sites of the catalyst, leading to catalyst poisoning and deactivation. Experiments show that lowering the pH from 14 to 13 and allowing it to stand for 8 h significantly reduced the HMF loss from 40% to 10%, indicating that lowering the alkalinity helps maintain the stability of HMF. However, at lower alkalinity, the formation rate of active species is slow, which in turn restricts the oxidation reaction. Therefore, developing HMFOR electrocatalysts that are suitable for low alkalinity conditions and possess both high activity and stability has become the key to solving the problem.

[0005] Layered double hydroxide (LDH) materials have attracted widespread attention in the field of electrocatalysis due to their abundant active sites, high specific surface area, and tunable electronic structure. The exposed metal centers on their surface can effectively lower the reaction energy barrier through a synergistic effect, promoting electrochemical processes. In this invention, the catalyst prepared by a simple non-equilibrium precipitation method combines low cost, abundant reserves, ease of preparation, and high efficiency. The introduction of manganese further enhances the reaction with OH-. - The adsorption capacity effectively enhances the generation rate of active species under low alkalinity conditions, thereby achieving efficient and stable electrocatalytic conversion of HMF in non-strongly alkaline media. Summary of the Invention

[0006] In view of this, the purpose of this invention is to solve the problem that the slow generation rate of active sites of the catalyst in the electrocatalytic oxidation of HMF in non-strongly alkaline media limits the oxidation process, and to propose a method for synthesizing a low-crystallinity layered double hydroxide catalyst.

[0007] The low-crystalline layered double hydroxide electrocatalyst material provided by this invention is a three-dimensional spherical structure constructed from two-dimensional NiFeMn LDH nanosheets, with a thickness of approximately 200 nm. This structure is beneficial for the exposure of catalyst adsorption sites and active sites, as well as for electrolyte diffusion and electron transport during the reaction process.

[0008] The method for synthesizing the electrocatalytic material is a simple, low-cost, high-performance, and long-life low-crystalline layered double hydroxide catalyst preparation method, which includes the following steps: (1) Pre-treat the copper foam to obtain the target copper foam that meets the preparation conditions; (2) Dissolve nickel nitrate, manganese nitrate and ferric nitrate in methanol and stir to form a homogeneous solution. Drop the mixed methanol solution onto the foamed copper obtained in step (1), dry it under an infrared lamp, and then immerse the dried sample in potassium hydroxide solution, where a vigorous non-equilibrium precipitation reaction occurs. After washing and drying, the low-crystalline layered double hydroxide catalyst is obtained.

[0009] Furthermore, step (1), which involves pretreating the copper foam to obtain the target copper foam that meets the preparation conditions, includes: 1) Cut the foam copper into 1×2 cm pieces. 2 A rectangular sheet of a certain size is used to obtain an initial copper foam of a predetermined size; 2) The foamed copper was ultrasonically cleaned in hydrochloric acid, acetone and ethanol for 15 min in sequence to obtain the initial foamed copper after the surface oil stains were removed. 3) Immerse the thoroughly cleaned copper foam in a solution containing 0.1 M ammonium persulfate and 1 M sodium hydroxide, and keep it undisturbed at room temperature for 60 min; 4) Place the oxidized copper foam in a vacuum oven at 40-80 ℃ and dry for 1-5 h; 5) The treated dried copper foam was heat-annealed in air at 250°C for 2 hours to obtain copper oxide nanowire arrays (NWAs).

[0010] Furthermore, the molar ratio of Ni, Fe and Mn in the mixed methanol solution in step (2) is 9:1:(3-6).

[0011] Furthermore, the volume of the mixed methanol solution dripped onto the copper foam in step (2) is 200-500 uL.

[0012] Furthermore, the concentration of the potassium hydroxide solution used for non-equilibrium precipitation in step (2) is 0.1-3.0 M. After cleaning and drying, the corresponding low-crystalline layered double hydroxide electrocatalyst material is obtained.

[0013] The application of the low-crystalline layered double hydroxide electrocatalyst material in the electrocatalytic oxidation of 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid shows that the reaction conditions are mild, the selectivity is high, and the anode catalyst has high stability to HMF.

[0014] The application of the low-crystalline layered double hydroxide catalyst in the electrocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid specifically includes the following steps: (1) An H-type electrolytic cell isolated by a Fumasep anion exchange membrane is used as the electrolytic cell, with two electrolytic chambers corresponding to the anode electrolytic chamber and the cathode electrolytic chamber, respectively. A three-electrode system is prepared using the low-crystalline layered double hydroxide catalyst as the working electrode, a Pt mesh as the counter electrode, an Hg / HgO electrode as the reference electrode, and an alkaline solution as the electrolyte; (2) 5-hydroxymethylfurfural was dissolved in the electrolyte and electrochemical catalytic oxidation reaction was carried out in an H-type electrolytic cell with an applied voltage to the three-electrode system.

[0015] Furthermore, the alkaline electrolyte in step (1) is an aqueous solution of potassium hydroxide, and the molar concentration of the electrolyte is 0.1-1.0 M.

[0016] Furthermore, in step (2), the 5-hydroxymethylfurfural is dissolved in the electrolyte at a molar concentration of 5-400 mM.

[0017] Furthermore, in step (2), the electrochemical catalytic oxidation reaction is carried out in an H-type electrolytic cell using a constant potential, wherein the constant potential is 1.0-1.8 V vs RHE, and the reaction time is 10-140 min.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The low-crystallinity double hydroxide catalyst prepared by this invention has the characteristics of a three-dimensional spherical structure constructed from two-dimensional nanosheets, which allows the catalyst adsorption sites and active sites to be fully exposed, promotes the generation efficiency of active substances, and thus realizes the adsorption and conversion of HMF in low-alkalinity electrolytes.

[0019] 2. The low-crystallinity double hydroxide catalyst prepared in this invention requires an onset potential of only about 1.3 V for the electrocatalytic HMF oxidation reaction.

[0020] 3. The synthesis method of the low-crystallinity double hydroxide catalyst obtained by this invention is simple and easy to implement.

[0021] 4. The active component of the low-crystalline double hydroxide obtained by this invention is a non-precious metal, which has the advantages of being inexpensive, readily available, and abundant in nature.

[0022] 5. The low-crystallinity double hydroxide catalyst prepared by this invention can achieve highly selective electrocatalytic oxidation of HMF under mild conditions.

[0023] 6. The low-crystallinity double hydroxide catalyst prepared by this invention exhibits excellent electrocatalytic oxidation performance of HMF in non-strongly alkaline media, and can achieve efficient conversion of HMF. It can achieve a conversion rate of 100.00%, FDCA selectivity of 93.80%, and Faraday efficiency of 92.82% in 20 mM HMF / 0.1 M KOH.

[0024] 7. The low-crystallinity double hydroxide catalyst prepared by this invention showed no significant deactivation after 10 consecutive reactions in an H-type electrolytic cell, indicating high catalyst stability.

[0025] 8. The low-crystallinity double hydroxide catalyst prepared by this invention possesses both long-range disorder and short-range order in its crystal structure. Its layered lattice exhibits lattice distortion and a high density of vacancy defects, exposing more active sites. Furthermore, its surface chemical structure displays abundant coordination unsaturated sites and highly reactive surface functional groups, effectively improving the catalyst's responsiveness to OH-. - The adsorption of HMF molecules enhances the performance of catalytic oxidation of HMF.

[0026] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0027] Figure 1 The X-ray diffraction (XRD) spectra of the low-crystallinity double hydroxide catalyst NiFeMn LDH obtained in Example 1 and the NiFe LDH obtained in Comparative Example 1 are shown. Figure 2 The images show scanning electron microscope (SEM) images, HRTEM images, and EDS spectra of the low-crystallinity double hydroxide catalyst NiFeMn LDH obtained in Example 1. Figure 3 The oxidation reaction polarization curves of the low-crystallinity NiFeMn LDH and NiFe LDH electrocatalytic materials obtained in Example 1 and Comparative Example 1 are shown. Figure 4 The graph shows a comparison of the HMF conversion (Con.), FDCA selectivity (Sel.), and Faraday efficiency (FE) of the low-crystallinity NiFeMn LDH and NiFe LDH electrocatalysts obtained in Example 1 and Comparative Example 1 in 20 mM HMF / 0.1 M KOH. Figure 5 The oxidation reaction polarization curves of the low-crystallinity Ni9Fe1Mn5 LDH obtained in Example 1 and the low-crystallinity Ni9Fe1Mn3LDH and Ni9Fe1Mn6 LDH electrocatalytic materials obtained in Example 2 are shown. Figure 6 The image shows the stability test results of the low-crystallinity NiFeMn LDH obtained in Example 1 after 10 consecutive electrolysis cycles. Detailed Implementation

[0028] To make the above-mentioned features and advantages of the present invention clearer, the present invention will be described in detail below with reference to specific embodiments. Unless otherwise specified, the methods of the present invention are conventional methods in the art. Example 1

[0029] Pretreatment of copper foam: Cut commercially available copper foam into 1×2 cm pieces. 2 The copper foam was then ultrasonically cleaned sequentially in hydrochloric acid, acetone, and ethanol for 15 min to remove surface dust, oil, and oxide layers. The thoroughly cleaned copper foam was then immersed in a solution containing 0.1 M ammonium persulfate and 1 M sodium hydroxide and held at room temperature for 60 min. After drying overnight, it was heat-annealed in air at 250°C for 2 hours to obtain copper oxide nanowire arrays (NWAs) for later use.

[0030] Accurately weigh 0.995 g of nickel nitrate hexahydrate, 0.162 g of ferric nitrate nonahydrate, and 0.513 g of manganese nitrate tetrahydrate, and dissolve them in 10 mL of methanol, stirring to form a homogeneous solution. Take 400 μL of the metal salt-methanol mixture and use a pipette to evenly drop the metal-methanol solution onto the treated copper foam at a depth of 1 × 1 cm. 2 Within the specified region, the sample was dried under an infrared lamp. Subsequently, the dried sample was immersed in a 2.0 M potassium hydroxide solution for 5 min, resulting in a vigorous non-equilibrium precipitation reaction. After washing and drying, the low-crystalline layered double hydroxide catalyst, denoted as NiFeMn LDH, was obtained. The XRD pattern of the prepared low-crystalline NiFeMn LDH catalyst is shown below. Figure 1 As shown, SEM and TEM images are as follows: Figure 2 As shown.

[0031] The catalyst prepared in this embodiment was used for the electrocatalytic oxidation of 5-hydroxymethylfurfural, and its electrocatalytic performance was measured. The specific implementation steps are as follows: Preparation of working electrode: The catalyst obtained in Example 1 was fixed with a Pt electrode clamp to prepare a working electrode.

[0032] Three-electrode system assembly: The working electrode serves as the anode, the platinum mesh as the counter electrode, and the Hg / HgO electrode as the reference electrode, and is fixed on an H-type electrolytic cell isolated by a Fumasep anion exchange membrane. The volume of the electrolytic cell is more than 10 mL.

[0033] Under ambient temperature and pressure conditions, using an assembled three-electrode system, with 0.1 M KOH solution and 0.1 M KOH + 20 mM HMF solution as the anode and cathode electrolytes, respectively, the reaction was conducted at a constant voltage of 1.45 V vs. RHE, a stirring speed of 800 rpm, a reaction temperature of 25°C, and a reaction time of 2.0 h. Electrocatalytic performance was then tested. After the reaction, the reaction solution was filtered and analyzed using an Agilent high-performance liquid chromatograph to determine the HMF conversion, FDCA selectivity, and Faraday efficiency. Figure 4 The results are shown in Table 1. Example 2

[0034] This embodiment provides a low-crystallinity double hydroxide, the synthesis steps of which are the same as in Example 1, except that the molar ratio of Ni, Fe and Mn is changed, and 0.513 g of manganese nitrate tetrahydrate is adjusted to 0.308 g and 0.616 g, respectively, which are represented as Ni9Fe1Mn3 LDH and Ni9Fe1Mn6 LDH.

[0035] In this embodiment, the same three-electrode system and the same reaction conditions as in Example 1 were used, and the results are shown in Table 1. Example 3

[0036] This embodiment provides a low-crystalline double hydroxide, the synthesis steps of which are the same as in Example 1, except that the concentration of potassium hydroxide in the non-equilibrium precipitation process is changed. The 2.0 M concentration of potassium hydroxide is adjusted to 1.0 M and 3.0 M, respectively, which are represented as NiFeMnLDH-1.0 and NiFeMnLDH-3.0.

[0037] In this embodiment, the same three-electrode system and the same reaction conditions as in Example 1 were used, and the results are shown in Table 1. Example 4

[0038] In this embodiment, the same three-electrode system and reaction conditions as in Example 1 were used. The only difference was that the HMF concentration was 50 mM.

[0039] Comparative Example 1

[0040] This comparative example used the same operation and feeding sequence as Example 1, the only difference being the absence of manganese nitrate tetrahydrate. The resulting catalyst was named NiFe LDH. XRD analysis confirmed that this catalyst was a layered double hydroxide, NiFeLDH. Figure 1 ).

[0041] In this comparative example, the same three-electrode system and the same reaction conditions as in Example 1 were used, and the results are shown in Table 1.

[0042] Comparative Example 2

[0043] This comparative example uses the same operation and feeding sequence as Example 1, the only difference being that ferric nitrate nonahydrate is not added, and the resulting catalyst is named NiMn LDH.

[0044] In this comparative example, the same three-electrode system and the same reaction conditions as in Example 1 were used, and the results are shown in Table 1.

[0045] Table 1. Performance evaluation of HMFOR by catalysts from examples and comparative examples.

[0046] Note: HMFOR potential is defined at a current density of 10 mA·cm⁻¹. -2 All measurements were converted to potentials relative to the hydrogen standard electrode (V vs. RHE).

[0047] Table 1 shows that the catalysts NiFeMn LDH, NiFe LDH, and NiMn LDH at a current density of 10 mA·cm⁻¹ -2 The corresponding potentials were 1.36 V, 1.50 V, and 1.35 V, respectively. After introducing manganese, the potential required for the material to reach the same current density decreased significantly, indicating that manganese-induced electronic interactions can effectively reduce the onset potential of the catalytic reaction. Specifically, in an electrolyte containing 0.1 M KOH and 20 mM HMF, the NiFeMn LDH material prepared in Example 1 of this invention achieved 100.00% HMF conversion, 93.80% FDCA selectivity, and 92.82% Faradaic efficiency under the stated conditions. In contrast, the conventional NiFe LDH electrode material not only showed a slower rate of current density increase but also exhibited an FDCA selectivity of 83.56% and a Faradaic efficiency of 82.69%, demonstrating significantly weaker catalytic performance than the manganese-modified layered double hydroxide catalyst NiFeMn LDH. As shown in Example 4, when the HMF concentration increases (50 mM), the NiFeMn LDH electrode material can still maintain 100.00% HMF conversion, 91.72% FDCA selectivity, and 90.92% Faraday efficiency. This indicates that the low-crystallinity NiFeMn LDH catalyst prepared by this method can effectively solve the problem of slow active site generation rate in the electrocatalytic oxidation of HMF in non-strongly alkaline media, improve the catalytic reaction efficiency, and is a very good electrocatalytic material.

[0048] Figure 1 The image shows the XRD pattern of the low-crystallinity NiFeMn LDH electrocatalyst material obtained in Example 1. As can be seen from the image, NiFeMnLDH and NiFe LDH were successfully synthesized.

[0049] Figure 2The images show SEM and TEM images of the low-crystallinity NiFeMn LDH electrocatalytic material obtained in Example 1. As can be seen from the images, NiFeMn LDH is a three-dimensional spherical structure constructed from two-dimensional nanosheets, with a thickness of approximately 200 nm.

[0050] Figure 3 The graph shows the oxidation reaction polarization curves of the low-crystallinity NiFeMn LDH and NiFe LDH electrocatalytic materials obtained in Example 1 and Comparative Example 1. As can be seen from the graph, at a current density of 10 / 50 mA cm⁻¹... -2 In the case of the low-crystallinity NiFeMn LDH electrode obtained in Example 1, the oxidation potential of HMF was 1.36 / 1.47 V vs. RHE (0.1 M KOH + 20 mM HMF). Compared with the NiFe LDH electrode obtained in Comparative Example 1 (1.50 / 1.60 V vs. RHE) and the electrode without HMF (1.39 / 1.61 V vs. RHE), it showed the lowest HMF oxidation potential, indicating that NiFeMn LDH can effectively catalyze the HMF oxidation reaction and has good HMF oxidation reaction kinetics.

[0051] Figure 4 The figure shows a comparison of the HMF conversion (Con.), FDCA selectivity (Sel.), and Faradaic efficiency (FE) of the low-crystalline NiFeMn LDH and NiFe LDH electrocatalysts obtained in Example 1 and Comparative Example 1. As can be seen from the figure, the low-crystalline NiFeMn LDH obtained in Example 1 achieved 100% HMF conversion, 93.80% yield, and 92.82% Faradaic efficiency. Compared to the NiFe LDH obtained in Comparative Example 1, which had a 100% HMF conversion, 83.56% FDCA selectivity, and 82.69% Faradaic efficiency, this indicates that the low-crystalline NiFeMn LDH catalyst exhibits superior selectivity for HMF oxidation, and that the electricity consumed in the reaction system is primarily used for HMF oxidation in the anode.

[0052] Figure 5 The oxidation reaction polarization curves of the low-crystallinity Ni9Fe1Mn5 LDH obtained in Example 1 and the low-crystallinity Ni9Fe1Mn3LDH and Ni9Fe1Mn6 LDH electrocatalytic materials obtained in Example 2 are shown. The rate of increase in current density with voltage initially increases and then decreases with increasing manganese content. The introduction of appropriate manganese content can induce electronic interactions, effectively improving the electrochemical performance of the catalyst.

[0053] Figure 6The figure shows the stability test results of the low-crystallinity NiFeMn LDH obtained in Example 1 after 10 consecutive electrolysis cycles. As can be seen from the figure, after 10 cycles, the FDCA selectivity and Faraday efficiency of NiFeMn LDH remained stable at over 92%, demonstrating good cycle stability.

[0054] The specific embodiments described above can further illustrate the purpose, technical solution and beneficial effects of the present invention. However, it should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for synthesizing a low-crystallinity layered double hydroxide catalyst for the electrocatalytic oxidation of HMF under low alkalinity conditions, characterized in that, Includes the following steps: (1) Pretreatment of copper foam; (2) At room temperature, nickel nitrate, manganese nitrate and ferric nitrate are dissolved in methanol and stirred to form a homogeneous solution; the mixed methanol solution is drop-coated onto the foam copper obtained in step (1), dried under an infrared lamp, and then the dried sample is immersed in potassium hydroxide solution, where a violent non-equilibrium precipitation reaction occurs. After washing and drying, the low-crystallinity layered double hydroxide catalyst is obtained.

2. The method according to claim 1, characterized in that, The pretreatment specifically includes: ultrasonically cleaning the copper foam in hydrochloric acid, acetone and ethanol for 15 min in sequence, then immersing the thoroughly cleaned copper foam in a solution containing 0.1 M ammonium persulfate and 1 M sodium hydroxide, keeping it still at room temperature for 60 min, drying it overnight, and then heat-annealing it in air at 250°C for 2 hours to obtain a copper oxide nanowire array.

3. The method according to claim 1, characterized in that, In step (2), the molar ratio of Ni, Fe and Mn in the mixed methanol solution is 9:1:(3-6).

4. The method according to claim 1, characterized in that, The volume of the mixed methanol solution dripped onto the copper foam in step (2) is 200-500 uL.

5. The method according to claim 1, characterized in that, The concentration of the potassium hydroxide solution in step (2) is 0.1-3.0 M.

6. A low-crystalline layered double hydroxide catalyst prepared by the method according to any one of claims 1-4.

7. The application of the low-crystalline layered double hydroxide catalyst as described in claim 6 in the electrocatalytic oxidation of 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid.

8. The application according to claim 7, characterized in that, The specific operation includes: using an H-type electrolytic cell isolated by anion exchange membrane as the electrolytic cell, with two electrolytic chambers corresponding to the anodic electrolytic chamber and the cathode electrolytic chamber, respectively; using the low-crystalline layered double hydroxide catalyst as the working electrode, a Pt mesh as the counter electrode, an Hg / HgO electrode as the reference electrode, and an alkaline solution as the electrolyte to prepare a three-electrode system; dissolving 5-hydroxymethylfurfural in the electrolyte, and performing an electrochemical catalytic oxidation reaction on the three-electrode system under an applied voltage in the H-type electrolytic cell.

9. The application according to claim 8, characterized in that, The alkaline solution is an aqueous solution of potassium hydroxide with a concentration of 0.1-1.0 M.

10. The application according to claim 8, characterized in that, 5-hydroxymethylfurfural is dissolved in the electrolyte at a molar concentration of 5-400 mM.

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