Ni-mo bimetallic supported carbon material, and preparation method and application thereof

Abstract

The application relates to the technical field of electrochemical materials, and particularly discloses a Ni-Mo bimetallic supported carbon material, a preparation method and application thereof. The preparation method comprises the following steps: first, a nitric acid solution is used to pretreat a carbon carrier to introduce oxygen-containing functional groups; second, a solvent and a reducing agent are prepared by using ethylene glycol, and then nickel and molybdenum bimetallic precursors are synchronously loaded by a solvothermal reaction under alkaline conditions; and finally, a staged heat treatment is carried out under an inert atmosphere to obtain a supported bimetallic catalyst with high dispersion of Ni-Mo bimetallic nanoparticles and strong interface combination with the carbon carrier. The material prepared by the application is used as a cathode and anode electrode to construct an HMFOR-HER coupling electrolysis system, which can significantly reduce the anode oxidation potential and the electrolytic cell voltage, realizes that the FDCA yield and the Faraday efficiency are both 95.16%, effectively reduces the hydrogen production energy consumption, and has a wide application prospect in the field of renewable energy hydrogen production coupled with biomass conversion.

Description

Technical Field

[0001] This invention relates to the field of electrochemical materials technology, and in particular to a Ni-Mo bimetallic supported carbon material, its preparation method, and its application. Background Technology

[0002] With the increasing severity of the global energy crisis and environmental pollution, the development of clean and renewable energy and chemical production technologies has become an urgent priority. Hydrogen energy, as an ideal energy carrier with high energy density and pollution-free combustion products, is considered an important component of the future energy system. Among these technologies, water electrolysis for hydrogen production, driven by renewable energy sources such as solar and wind power, has attracted significant attention due to its green, environmentally friendly, and sustainable advantages. However, the traditional water electrolysis process is severely limited by the slow kinetics of the oxygen evolution reaction (OER). This reaction not only requires a high overpotential, resulting in low overall energy conversion efficiency, but also produces oxygen with low economic value and poses safety hazards due to hydrogen-oxygen mixing. Meanwhile, biomass, as the most abundant renewable organic carbon source on Earth, is crucial for achieving sustainable development through its efficient conversion into high-value-added chemicals. 5-Hydroxymethylfurfural (HMF), as one of the most important biomass-derived platform molecules, can be obtained through cellulose hydrolysis. Its oxidation product, 2,5-furandicarboxylic acid (FDCA), is a key monomer for the synthesis of bio-based biodegradable plastic polyethylene furandicarboxylate (PEF), and is expected to replace petroleum-based terephthalic acid (PTA), with broad market prospects.

[0003] Electrocatalytic oxidation of 5-hydroxymethylfurfural coupled with hydrogen production offers a highly attractive approach to simultaneously addressing the aforementioned challenges. This technology replaces the traditional anode OER in water electrolysis with the thermodynamically and kinetically more favorable HMF oxidation reaction (HMFOR). This not only significantly reduces the cell voltage required for hydrogen production and improves energy efficiency, but also simultaneously produces high-value-added FDCA at the anode while generating hydrogen at the cathode, achieving a highly efficient conversion of electrical energy into chemical energy. Furthermore, this technology avoids the safety risks associated with hydrogen-oxygen mixing, and the reaction conditions are mild, requiring no high temperature, high pressure, or expensive chemical oxidants, aligning with the principles of green chemistry. However, the practical application of this technology still faces numerous challenges. The core issue lies in developing efficient, stable, and low-cost bifunctional electrocatalysts capable of simultaneously catalyzing the anode HMFOR and the cathode hydrogen evolution reaction (HER), exhibiting excellent catalytic activity, product selectivity, and long-term stability.

[0004] Currently, reported catalysts for HMFOR and HER mainly fall into two categories: noble metal-based catalysts and non-noble metal-based catalysts. While noble metal-based catalysts such as Pt, Pd, and Au exhibit high catalytic activity, their scarcity and high cost hinder large-scale industrial application. Among numerous non-noble metal catalysts, transition metal-based materials have attracted widespread attention due to their abundant reserves, low cost, and tunable electronic structure and catalytic performance. Some transition metal-based materials demonstrate certain catalytic activity for HMF oxidation, while others show good performance in the hydrogen evolution reaction. However, most transition metal-based catalysts can only catalyze a single reaction, and bifunctional catalysts capable of simultaneously and efficiently catalyzing both HMFOR and HER remain relatively scarce.

[0005] Therefore, developing an electrocatalyst that combines excellent HMFOR and HER bifunctional catalytic activity, high selectivity, good stability, and low cost is of great significance for promoting the industrial application of electrocatalytic oxidation of 5-hydroxymethylfurfural coupled with hydrogen production technology. Summary of the Invention

[0006] In view of the lack of non-precious metal bifunctional electrocatalysts that can simultaneously and efficiently catalyze the oxidation of 5-hydroxymethylfurfural (HMFOR) and the hydrogen evolution reaction (HER) in the existing technology, this invention provides a Ni-Mo bimetallic supported carbon material, its preparation method and application.

[0007] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: In a first aspect, the present invention provides a method for preparing a Ni-Mo bimetallic supported carbon material, comprising the following steps: S1, add the carbon support to the nitric acid solution, impregnate, separate the solid and liquid, wash, and dry to obtain the pretreated carbon support; S2, the pretreated carbon support is dispersed in ethylene glycol, a nickel source and a molybdenum source are added, the pH of the system is adjusted to alkaline with ammonia, and a solvothermal reaction is carried out by heating to obtain a nickel-molybdenum-carbon composite. S3, the nickel-molybdenum-carbon composite is subjected to staged heat treatment under an inert atmosphere to obtain Ni-Mo bimetallic supported carbon material.

[0008] Compared to existing technologies, the method for preparing Ni-Mo bimetallic supported carbon materials provided by this invention first pretreats the carbon support with nitric acid solution. The oxidation effect of nitric acid introduces oxygen-containing functional groups such as hydroxyl, carboxyl, and carbonyl groups onto the surface of the carbon material. These oxygen-containing functional groups not only improve the dispersibility of the carbon support in polar solvents such as ethylene glycol, but also serve as adsorption and anchoring sites for Ni and Mo metal precursors. This effectively promotes the adsorption and uniform distribution of Ni and Mo metal precursors on the carbon support surface, preventing metal particle aggregation during subsequent reactions. Simultaneously, it enhances the interfacial interaction between the metal and the carbon support, increasing the binding strength of the metal active sites and preventing their detachment and dissolution during long-term electrolysis, thereby significantly improving the stability of the catalyst.

[0009] Based on this, the present invention further constructs an ethylene glycol-ammonia alkaline solvothermal system; wherein, ethylene glycol acts as a solvent, dispersion medium and reducing agent in the system; ammonia is used to adjust the alkalinity of the system and affect the hydrolysis, complexation and deposition process of the metal precursor, so that Ni and Mo precursors can be transformed, deposited and compounded in the same reaction system in a relatively coordinated manner, thereby forming a uniformly distributed and closely contacted Ni-Mo bimetallic structure on the carbon support surface.

[0010] Finally, the phased heat treatment effectively avoids the rapid growth and agglomeration of metal particles at high temperatures, maintaining their small particle size and high dispersibility. The heat treatment process can also further enhance the electronic interaction between the metal and the carbon support, regulate the electronic structure of the active sites, thereby improving the catalytic activity and product selectivity of the catalyst for HMFOR and HER.

[0011] Therefore, this invention does not simply involve loading Ni and Mo metal components onto the surface of carbon materials. Instead, it achieves uniform loading, tight composite structure, and optimized electronic structure of Ni and Mo bimetallic components through a composite control method involving nitric acid pretreatment, ethylene glycol / ammonia solvothermal synergistic deposition, and staged heat treatment to stabilize the structure. The Ni-Mo bimetallic nanoparticles are uniformly dispersed on the carbon support surface, with a narrow particle size distribution, abundant exposed active sites, and an optimized electronic structure. As a bifunctional electrocatalyst, they exhibit excellent catalytic performance in the electrocatalytic oxidation of 5-hydroxymethylfurfural coupled with hydrogen production. They can achieve efficient hydrogen production and highly selective synthesis of 2,5-furandicarboxylic acid at relatively low cell voltage, and possess good long-term cycling stability, showing broad prospects for industrial application.

[0012] Furthermore, in S1, the carbon support is Vulcan XC-72 carbon black.

[0013] Further, in S1, the mass-to-volume ratio of the carbon support to the nitric acid solution is 1 g: (20~80) mL; the concentration of the nitric acid solution is 1 mol / L~3 mol / L.

[0014] The optimal ratio range ensures the efficient and uniform introduction of sufficient oxygen-containing functional groups onto the carbon support surface, while avoiding excessive etching, framework structure damage, and specific surface area reduction caused by excessive nitric acid concentration or dosage. This provides ideal support surface conditions for the uniform loading and stable bonding of subsequent Ni and Mo metal components.

[0015] Furthermore, in S1, the impregnation temperature is 20℃~40℃, and the reaction time is 24h~48h.

[0016] The optimal pretreatment temperature and time allow nitric acid to fully penetrate into the pore structure of the carbon support, achieving a uniform distribution of oxygen-containing functional groups on the surface and within the pores of the carbon support. This avoids localized over-etching and structural damage that can easily result from high-temperature immersion, providing a uniform surface environment for the subsequent uniform adsorption and anchoring of Ni and Mo metal ions across the entire surface of the support.

[0017] It should be noted that the present invention does not impose any particular limitation on the types of nickel and molybdenum sources. Any precursor that can provide nickel and molybdenum ions and can be reduced or converted under solvothermal conditions can be used.

[0018] In specific implementations, the nickel source may be at least one of nickel nitrate, nickel chloride, nickel sulfate, nickel acetate, nickel acetylacetonate and their hydrates, preferably nickel nitrate; the molybdenum source may be at least one of ammonium molybdate, sodium molybdate, phosphomolybdic acid, molybdenum acetylacetonate and their hydrates, preferably ammonium molybdate.

[0019] Further, in S2, the mass-to-volume ratio of the pretreated carbon support to ethylene glycol is 1 g: (30~80) mL.

[0020] In this invention, ethylene glycol is not merely used to provide the reaction solvent, but rather to regulate the dispersion state of the carbon support, the mass transfer process of the metal precursor, and the mild reducing ability of ethylene glycol on the metal precursor in the entire solvothermal system. If the amount of ethylene glycol is too low, the local concentration of metal ions in the system will be high, and the Ni and Mo precursors will easily undergo rapid hydrolysis or local deposition, leading to particle agglomeration and uneven component distribution. If the amount of ethylene glycol is too high, the viscosity of the system will increase, and the diffusion and nucleation deposition rate of metal ions will decrease, which is not conducive to the effective loading of Ni and Mo components.

[0021] Therefore, by limiting the mass-to-volume ratio of the pretreated carbon support to ethylene glycol, the present invention enables the carbon support to be fully dispersed in ethylene glycol to form a uniform and stable suspension system, allowing each support particle to fully contact the metal precursor while maintaining a suitable metal ion concentration and reduction deposition rate, thereby ensuring the effective loading and uniform distribution of Ni and Mo components on the surface of the carbon support.

[0022] Further, in S2, the mass ratio of the pretreatment carrier to the nickel source is 1:(1~1.6).

[0023] This invention controls the mass ratio of the pretreated carrier to the nickel source, ensuring that the amount of nickel source matches the anchoring points on the carbon carrier surface. If the amount of nickel source is too low, there are insufficient active sites; if the amount is too high, nickel species tend to self-nucleate and aggregate, reducing the utilization rate of active sites. This controlled ratio promotes uniform nucleation and deposition of nickel species on the pretreated carbon carrier surface, providing a basis for the formation of a tight composite structure between nickel and molybdenum species.

[0024] Furthermore, in S2, the atomic molar ratio of Ni in the nickel source to Mo in the molybdenum source is (0.7~1.85):1.

[0025] By adjusting the ratio of nickel to molybdenum sources, the composition of the active phase, electronic structure, and density of surface active sites in the final Ni-Mo bimetallic material can be optimized. Ni and Mo differ in their electronic structure, coordination state, and hydrolysis, reduction, and deposition behaviors during solvothermal reactions. An inappropriate ratio can easily lead to excessive deposition of a single metal component, insufficient Ni / Mo contact, or inadequate bimetallic synergy. This invention, by limiting the atomic molar ratio of Ni to Mo, enables Ni and Mo species to transform and deposit at a more matched rate during solvothermal processes, thereby promoting the formation of a uniformly distributed and tightly contacted Ni-Mo bimetallic composite structure on the carbon support surface.

[0026] Preferably, in S2, the atomic molar ratio of Ni in the nickel source to Mo in the molybdenum source is 10:7.

[0027] When the atomic molar ratio of Ni to Mo is 10:7, the number of Ni active sites, the regulatory effect of Mo on the electronic structure of Ni, and the synergistic effect of the bimetallic interface can be well balanced in the resulting material, thus obtaining a bifunctional electrocatalyst with better catalytic performance.

[0028] Further in S2, alkalinity refers to a pH value of 10 to 11.

[0029] The alkaline solvothermal environment created by using ammonia in this invention is crucial for the effective utilization of the aforementioned nickel and molybdenum sources. Ammonia not only adjusts the pH but also influences the hydrolysis, complexation, and nucleation deposition processes of the metal precursors. Under these conditions, nickel ions can be converted into hydroxide or oxide precursor nuclei relatively slowly and uniformly. Simultaneously, ammonia molecules can complex with nickel ions, slowing down the instantaneous precipitation rate of nickel species and preventing their rapid precipitation and large particle aggregation in localized areas. The molybdenum source can interact with nickel species in the alkaline environment, participating in recombination during nickel species formation and deposition, thereby improving the contact degree and distribution uniformity between the Ni and Mo components.

[0030] Furthermore, in S2, the temperature of the solvothermal reaction is 100℃~130℃, and the reaction time is 20h~28h.

[0031] This invention employs a mild solvothermal reaction temperature of 100℃ to 130℃. This temperature range allows ethylene glycol to exert a moderate reducing effect in a closed solvothermal environment, and together with the alkaline environment formed by ammonia, it regulates the nucleation, growth, and deposition processes of Ni and Mo metal precursors. If the solvothermal temperature is too low, the reducing power of ethylene glycol is insufficient, the conversion rate of metal precursors is slow, and it is easy to lead to insufficient deposition of Ni and Mo components and a limited number of active sites. If the temperature is too high, the reducing effect of ethylene glycol is enhanced, the nucleation and growth rate of metal species is too fast, which can easily cause particle agglomeration, widening of particle size distribution, and even cause ethylene glycol decomposition side reactions, affecting the material structure and catalytic performance.

[0032] Therefore, this invention controls the solvothermal temperature at 100℃~130℃ and, with a reaction time of 20h~28h, allows the Ni and Mo metal precursors to be fully converted and uniformly deposited on the carbon support surface under relatively mild conditions. These conditions avoid particle agglomeration and size inhomogeneity caused by excessively rapid metal ion reduction, while also enabling sufficient contact and effective composite formation between the Ni and Mo components. This results in Ni-Mo bimetallic nanoparticles with good crystallinity, excellent dispersibility, and regulated electronic structure. Furthermore, the reaction conditions are mild, energy-efficient, and highly safe, making them suitable for subsequent scale-up preparation.

[0033] It is important to emphasize that, due to the different electronic states and transformation behaviors of Ni and Mo precursors, they are prone to problems such as mismatched deposition rates, preferential precipitation of a single metal, or uneven component distribution in conventional systems. This invention, by controlling the amount of ethylene glycol, system pH, Ni / Mo ratio, and solvothermal temperature, makes the deposition process of Ni and Mo species more coordinated, reducing problems such as component separation, preferential precipitation of a single metal, or particle agglomeration. The resulting Ni-Mo component can be uniformly distributed and closely contacted on the carbon support surface, which is conducive to the formation of bimetallic active sites with synergistic effects. At the same time, by regulating the electronic structure of Ni by Mo, the bifunctional catalytic performance of the catalyst in HMFOR and HER reactions is improved.

[0034] Furthermore, in S3, the staged heat treatment specifically includes the following steps: First, raise the temperature to 150℃~250℃ at a rate of 1℃ / min~5℃ / min and hold for 0.5h~1h. Then, raise the temperature to 400℃~500℃ at a rate of 1℃ / min~5℃ / min and hold for 0.5h~1h.

[0035] The staged heating heat treatment process described above can gradually remove residual solvents, unreacted precursors, and volatile impurities from the material, while simultaneously promoting the formation of the Ni-Mo bimetallic alloy phase and optimizing its crystallinity. Compared to single-temperature heat treatment, staged heat treatment effectively avoids the rapid growth and agglomeration of metal particles at high temperatures, maintaining their small particle size and high dispersibility. Furthermore, the heat treatment process can further enhance the electronic interactions between the metal and the carbon support, modulating the electronic structure of the active sites, thereby improving the catalytic activity and product selectivity of the catalyst for HMFOR and HER.

[0036] Secondly, the present invention also provides a Ni-Mo bimetallic supported carbon material, which is prepared by the preparation method of Ni-Mo bimetallic supported carbon material described in any one of the above claims.

[0037] Specifically, in the Ni-Mo bimetallic supported carbon material, the Ni-Mo bimetallic active components are uniformly and highly dispersed in the form of nanoparticles on the surface of a carbon support pretreated with nitric acid. The metal particles are small and uniform in size, and form strong interfacial interactions with the carbon support through chemical bonding, effectively preventing the migration, aggregation, and detachment of the metal active components during the catalytic reaction. Simultaneously, a close synergistic effect is formed between the Ni and Mo metal components in the material. The introduction of Mo effectively modulates the electronic structure of Ni, optimizing the adsorption energy of the active sites for reactants and intermediates.

[0038] This Ni-Mo bimetallic supported carbon material possesses excellent catalytic activity for both the anodic 5-hydroxymethylfurfural oxidation (HMFOR) and cathodic hydrogen evolution reaction (HER), exhibiting high selectivity for 2,5-furandicarboxylic acid (FDCA) and demonstrating good stability during long-term electrolysis. Therefore, this material can be used as a bifunctional electrocatalyst in the electrocatalytic oxidation of 5-hydroxymethylfurfural coupled with hydrogen production, significantly reducing cell voltage and improving energy conversion efficiency. Simultaneously, it enables the green production of high-purity hydrogen and FDCA, effectively solving the problems of low efficiency and poor stability of existing non-precious metal catalysts. It shows promising application prospects in green hydrogen production and biomass high-value conversion.

[0039] Thirdly, the present invention also provides an electrode comprising the aforementioned Ni-Mo bimetallic supported carbon material.

[0040] Fourthly, the present invention also provides the application of the above-mentioned Ni-Mo bimetallic supported carbon material or the electrode in the electrocatalytic oxidation of 5-hydroxymethylfurfural coupled to produce hydrogen.

[0041] In the above applications, the Ni-Mo bimetallic supported carbon material provided by this invention is used as the catalytically active component of the electrode. In specific implementations, electrolysis is performed using a three-electrode system or a two-electrode system. When using a three-electrode system, the electrode loaded with the Ni-Mo bimetallic supported carbon material of this invention is used as the working electrode, a platinum sheet, carbon rod, or nickel foam is used as the counter electrode, and a mercury / mercury oxide electrode or a silver / silver chloride electrode is used as the reference electrode. When using a two-electrode system, both the anode and cathode can be electrodes loaded with the Ni-Mo bimetallic supported carbon material of this invention to achieve bifunctional catalysis. The electrolyte is an alkaline solution containing 5-hydroxymethylfurfural. The alkaline electrolyte can be potassium hydroxide or sodium hydroxide, etc. The concentration of 5-hydroxymethylfurfural is typically 5~20 mmol / L, and the concentration of the alkaline electrolyte is generally 0.5~1.5 mol / L. The reaction can be carried out at room temperature or under appropriate heating conditions. When a voltage is applied for electrocatalytic oxidation, the anode mainly undergoes the oxidation of 5-hydroxymethylfurfural, which selectively produces 2,5-furandicarboxylic acid, while the cathode undergoes the hydrogen evolution reaction, producing high-purity hydrogen gas.

[0042] Fifthly, the present invention also provides a method for electrocatalytic oxidation of 5-hydroxymethylfurfural coupled with hydrogen production, comprising the following steps: using a two-electrode system, with the Ni-Mo bimetallic supported carbon material serving as both the anode and cathode as the electrocatalytic active components, placing the anode and cathode in an alkaline electrolyte containing 5-hydroxymethylfurfural, applying a voltage between the two electrodes to carry out the electrocatalytic oxidation reaction, oxidizing 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid at the anode, and simultaneously generating hydrogen gas at the cathode.

[0043] Specifically, the material can be loaded onto a conductive substrate (such as carbon paper, carbon cloth, nickel foam, etc.) by methods such as drop coating or in-situ growth, and used directly as the hydrogen evolution cathode and HMF oxidation anode, respectively. They are placed together in an alkaline electrolyte containing 5-hydroxymethylfurfural, and the hydrogen evolution reaction (HER) at the cathode and the 5-hydroxymethylfurfural oxidation reaction (HMFOR) at the anode can be driven synchronously by applying a voltage between the two electrodes.

[0044] The electrocatalytic oxidation of 5-hydroxymethylfurfural coupled with hydrogen production provided by this invention fully utilizes the excellent bifunctional catalytic properties of the Ni-Mo bimetallic supported carbon material of this invention. It achieves simultaneous and efficient driving of HMFOR at the anode and HER at the cathode in a single electrolytic cell, eliminating the need for a reference electrode. The system is simple in structure and easy to operate. Furthermore, both the anode and cathode use non-precious metal catalysts, effectively avoiding the use of precious metals and further enhancing the economic viability and industrial application prospects of this coupling technology.

[0045] Furthermore, the concentration of 5-hydroxymethylfurfural in the alkaline electrolyte is 8 mmol / L to 12 mmol / L.

[0046] Specifically, the alkaline electrolyte is a potassium hydroxide solution, preferably with a concentration of 0.8 mol / L to 1.2 mol / L.

[0047] Furthermore, the voltage of the electrocatalytic oxidation reaction is (1.48~1.60) V (vs RHE), preferably (1.50~1.55) V (vs RHE), and more preferably 1.54 V (vs RHE).

[0048] Experimental results show that the Ni-Mo bimetallic supported carbon material prepared in this invention can effectively construct an HMFOR-HER coupled electrolysis system in which the 5-hydroxymethylfurfural oxidation reaction replaces the traditional oxygen evolution reaction, thereby significantly reducing the energy consumption of the anodic reaction. In a 1M KOH electrolyte containing 10mM 5-HMF, when the current density is 10mA / cm², 2 At this time, the anodic potential of HMFOR was 39 mV lower than that of OER, demonstrating the significant advantage of this system in reducing anodic energy consumption. Simultaneously, this catalyst exhibited excellent product formation ability during the electro-oxidation of 5-HMF, achieving a yield and Faradaic efficiency of 95.16% for 2,5-furandicarboxylic acid at 1.54 V (vs. RHE). In the two-electrode system, compared with the traditional OER-HER water electrolysis system, the HMFOR-HER system using the catalyst of this invention showed a higher yield at 10 mA / cm². 2 and 20 mA / cm 2 The cell voltage decreased by 59 mV and 63 mV under different current densities, respectively. These results demonstrate that the Ni-Mo bimetallic supported carbon material of this invention can effectively reduce energy consumption during electrolysis while achieving efficient and selective conversion of 5-hydroxymethylfurfural to the high-value-added product 2,5-furandicarboxylic acid, exhibiting good potential for practical applications.

[0049] In summary, this invention discloses a Ni-Mo bimetallic supported carbon material, its preparation method, and its applications. The preparation method first pretreats the carbon support with nitric acid solution to introduce oxygen-containing functional groups. Then, using ethylene glycol as a solvent and reducing agent, nickel and molybdenum bimetallic precursors are simultaneously loaded via a solvothermal reaction under alkaline conditions. Finally, a staged heat treatment is performed under an inert atmosphere to obtain a supported bifunctional electrocatalyst with highly dispersed Ni-Mo bimetallic nanoparticles and strong interfacial bonding with the carbon support. Using the material prepared in this invention as the cathode and cation dual-electrode to construct an HMFOR-HER coupled electrolysis system can significantly reduce the anodic oxidation potential and electrolyzer voltage. While achieving FDCA yield and Faraday efficiency of 95.16%, it effectively reduces hydrogen production energy consumption. This provides a practical technical solution for the green, safe, and efficient simultaneous production of hydrogen and bio-based high-value chemicals, and has broad application prospects in the field of renewable energy hydrogen production coupled with biomass conversion. Attached Figure Description

[0050] Figure 1 The image shows the XRD pattern of the Ni-Mo bimetallic carbon-supported material prepared in Example 1 of this invention. Figure 2 The electrochemical performance of the Ni-Mo bimetallic supported carbon material prepared in Example 1 of this invention was tested in a 1.0 mol / L KOH solution, including (a) a linear voltammetry (LSV) curve, (b) a Tafel plot, and (c) a current density of 10 mA / cm². 2 Overpotential comparison chart; Figure 3 The electrochemical performance of the Ni-Mo bimetallic supported carbon material prepared in Example 1 of this invention was tested in 1M KOH solution with / without 10mM 5-HMF, wherein (a) is a linear voltammetry (LSV) curve, (b) is a Tafel plot, and (c) is a current density of 10mA / cm². 2 Time-over-potential comparison diagram, (d) EIS impedance test diagram; Figure 4 Electrochemical active area test of Ni-Mo bimetallic supported carbon material prepared in Example 1 of this invention: (a) CV curves at different scan rates, (b) linear relationship between ΔJ / 2 and scan rate. Figure 5 The FDCA selectivity and Faraday efficiency (FE) of the Ni-Mo bimetallic supported carbon material prepared in Example 1 of this invention for catalyzing 5-HMF at different voltages; Figure 6 Cyclic stability test of the Ni-Mo bimetallic supported carbon material prepared in Example 1 of this invention at the optimal voltage; Figure 7 This is an HPLC trace image of the Ni-Mo bimetallic supported carbon material prepared in Example 1 of the present invention undergoing potentiostatic catalysis of 5-HMF oxidation at 1.54V vs. RHE voltage; Figure 8 The figure shows a comparison of linear sweep voltammetry curves in a two-electrode system, using the Ni-Mo / C prepared in Example 1 as the catalyst, in a 1M KOH electrolyte without 5-HMF (OER-HER coupling system) and a 1M KOH electrolyte containing 10mM 5-HMF (HMFOR-HER coupling system). Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0052] The present invention first pretreats the carbon black support with nitric acid, then adds a nickel source and a molybdenum source to the ethylene glycol system, and adjusts the system to be alkaline by ammonia water. After solvothermal reaction and segmented heat treatment under nitrogen atmosphere, a carbon black-supported nickel-molybdenum bimetallic catalyst Ni-Mo / C is obtained.

[0053] The obtained catalyst can be further prepared into an electrode and used in the oxidative coupling hydrogen evolution reaction system of 5-hydroxymethylfurfural.

[0054] To better illustrate the present invention, further examples are provided below.

[0055] Example 1 This embodiment provides a method for preparing Ni-Mo bimetallic supported carbon material, including the following steps: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 50 mL of 2 M nitric acid solution and stirred at room temperature for 48 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 22.5 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.75 g of nickel nitrate hexahydrate, 0.3 g of ammonium molybdate tetrahydrate, 2.5 mL of deionized water and 1 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 110 °C for 24 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a nickel-molybdenum-carbon composite. S3. The dried nickel-molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, it was heated to 200°C at a heating rate of 5°C / min and held for 0.5 h. Next, it was heated to 450°C at a heating rate of 5°C / min and held for 1 h. After natural cooling to room temperature, the Ni-Mo / C catalyst was obtained, denoted as Ni-Mo / C-10:7.

[0056] Example 2 This embodiment provides a method for preparing Ni-Mo bimetallic supported carbon material, including the following steps: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 20 mL of 1 M nitric acid solution and stirred at room temperature for 24 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 15 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.638 g of nickel nitrate hexahydrate, 0.364 g of ammonium molybdate tetrahydrate, 2.5 mL of deionized water and 0.5 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 100 °C for 20 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a nickel-molybdenum-carbon composite. S3. The dried nickel-molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, it was heated to 150°C at a heating rate of 1°C / min and held for 0.5 h. Next, it was heated to 400°C at a heating rate of 1°C / min and held for 0.5 h. After natural cooling to room temperature, the Ni-Mo / C catalyst was obtained, denoted as Ni-Mo / C-1:1.

[0057] Example 3 This embodiment provides a method for preparing Ni-Mo bimetallic supported carbon material, including the following steps: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 80 mL of 3M nitric acid solution and stirred at room temperature for 36 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 20 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.511 g of nickel nitrate hexahydrate, 0.443 g of ammonium molybdate tetrahydrate, 2.5 mL of deionized water and 1.5 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 130 °C for 28 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a nickel-molybdenum-carbon composite. S3. The dried nickel-molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, the temperature was increased to 250°C at a rate of 3°C / min and held for 1 h. Next, the temperature was increased to 500°C at a rate of 3°C / min and held for 1.5 h. The mixture was then naturally cooled to room temperature to obtain the Ni-Mo / C catalyst, denoted as Ni-Mo / C-7:10.

[0058] Example 4 This embodiment provides a method for preparing Ni-Mo bimetallic supported carbon material, including the following steps: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 40 mL of 2 M nitric acid solution and stirred at room temperature for 24 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 30 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.805 g of nickel nitrate hexahydrate, 0.267 g of ammonium molybdate tetrahydrate, 2.5 mL of deionized water and 0.5 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 100 °C for 20 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed twice with water and twice with acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a nickel-molybdenum-carbon composite. S3. The dried nickel-molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, the temperature was increased to 150°C at a rate of 2°C / min and held for 1 h. Next, the temperature was increased to 400°C at a rate of 2°C / min and held for 1.5 h. The mixture was then naturally cooled to room temperature to obtain the Ni-Mo / C catalyst, denoted as Ni-Mo / C-11:6.

[0059] Example 5 This embodiment provides a method for preparing Ni-Mo bimetallic supported carbon material, including the following steps: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 70 mL of 2 M nitric acid solution and stirred at room temperature for 36 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 40 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.659 g of nickel nitrate hexahydrate, 0.356 g of ammonium molybdate tetrahydrate, 2.5 mL of deionized water and 1.5 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 130 °C for 28 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a nickel-molybdenum-carbon composite. S3. The dried nickel-molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, it was heated to 250°C at a heating rate of 4°C / min and held for 0.5 h. Next, it was heated to 500°C at a heating rate of 4°C / min and held for 0.5 h. After natural cooling to room temperature, the Ni-Mo / C catalyst was obtained, denoted as Ni-Mo / C-9:8.

[0060] Comparative Example 1 This comparative example provides a method for preparing Ni-supported carbon materials, which differs from Example 1 only in that ammonium molybdate tetrahydrate is not added in step S2. The method specifically includes the following steps: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 50 mL of 2 M nitric acid solution and stirred at room temperature for 48 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 22.5 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.75 g of nickel nitrate hexahydrate, 2.5 mL of deionized water and 1 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 110 °C for 24 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a nickel-carbon composite. S3. The dried nickel-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, it was heated to 200°C at a heating rate of 5°C / min and held for 0.5 h. Next, it was heated to 450°C at a heating rate of 5°C / min and held for 1 h. It was then naturally cooled to room temperature to obtain the Ni / C catalyst.

[0061] Comparative Example 2 This comparative example provides a method for preparing a Mo-supported carbon material, which differs from Example 1 only in that nickel nitrate hexahydrate is not added in step S2. The method specifically includes the following steps: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 50 mL of 2 M nitric acid solution and stirred at room temperature for 48 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 22.5 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.3 g of ammonium molybdate tetrahydrate, 2.5 mL of deionized water and 1 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 110 °C for 24 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a molybdenum-carbon composite. S3. The dried molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, it was heated to 200°C at a heating rate of 5°C / min and held for 0.5 h. Next, it was heated to 450°C at a heating rate of 5°C / min and held for 1 h. It was then naturally cooled to room temperature to obtain the Mo / C catalyst.

[0062] Comparative Example 3 This comparative example provides a method for preparing Ni-Mo bimetallic supported carbon materials. The only difference from Example 1 is that the carbon support is not pretreated with nitric acid; instead, Vulcan XC-72 carbon black is used directly as the support. The specific steps include the following: S1, 0.5g of Vulcan XC-72 carbon black was added to 22.5mL of ethylene glycol and ultrasonically dispersed for 30min to obtain a carbon support dispersion; 0.75g of nickel nitrate hexahydrate, 0.3g of ammonium molybdate tetrahydrate, 2.5mL of deionized water and 1mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1min, and then transferred to a 50mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 110℃ for 24h. After the reaction was completed, the product was collected by centrifugation at 3000rpm for 10min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60℃ for 12h to obtain a nickel-molybdenum-carbon composite. S2. The dried nickel-molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, it was heated to 200°C at a heating rate of 5°C / min and held for 0.5 h. Next, it was heated to 450°C at a heating rate of 5°C / min and held for 1 h. After natural cooling to room temperature, the Ni-Mo / C catalyst was obtained, denoted as Ni-Mo / C-raw.

[0063] Comparative Example 4 This comparative example provides a method for preparing Ni-Mo bimetallic supported carbon materials. The only difference from Example 1 is that the carbon support is pretreated with hydrochloric acid in step S1. The specific steps include the following: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 50 mL of 2 M hydrochloric acid solution and stirred at room temperature for 48 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 22.5 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.75 g of nickel nitrate hexahydrate, 0.3 g of ammonium molybdate tetrahydrate, 2.5 mL of deionized water and 1 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 110 °C for 24 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a nickel-molybdenum-carbon composite. S3. The dried nickel-molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, it was heated to 200°C at a heating rate of 5°C / min and held for 0.5 h. Next, it was heated to 450°C at a heating rate of 5°C / min and held for 1 h. It was then naturally cooled to room temperature to obtain the Ni-Mo / C catalyst, denoted as Ni-Mo / C-10:7 (hydrochloric acid).

[0064] Comparative Example 5 This comparative example provides a method for preparing Ni-Mo bimetallic supported carbon material. The only difference from Example 1 is that step S3 does not use a staged heat treatment method, but instead uses a single heat treatment method, which specifically includes the following steps: S1, Under magnetic stirring, 1.0 g of Vulcan XC-72 carbon black was added to 50 mL of 2 M nitric acid solution and stirred at room temperature for 48 h. Then, the mixture was centrifuged at 3000 rpm for 5 min, the product was collected and washed three times with water, and dried at 60 °C to obtain the pretreated carbon support. S2, 0.5 g of pretreated carbon support was added to 22.5 mL of ethylene glycol and ultrasonically dispersed for 30 min to obtain a carbon support dispersion; 0.75 g of nickel nitrate hexahydrate, 0.3 g of ammonium molybdate tetrahydrate, 2.5 mL of deionized water and 1 mL of ammonium hydroxide were mixed and dissolved, and then added to the carbon support dispersion. The mixture was stirred at room temperature for 1 min, and then transferred to a 50 mL polytetrafluoroethylene-lined reactor. The mixture was hydrothermally reacted at 110 °C for 24 h. After the reaction was completed, the product was collected by centrifugation at 3000 rpm for 10 min. The product was washed three times each with water and acetone, and finally washed with methanol. The product was dried at 60 °C for 12 h to obtain a nickel-molybdenum-carbon composite. S3. The dried nickel-molybdenum-carbon composite was placed in a tube furnace and heated to 80°C within 30 min under a nitrogen atmosphere. Then, it was heated to 450°C at a heating rate of 5°C / min and held for 1.5 h. After natural cooling to room temperature, the Ni-Mo / C catalyst was obtained, denoted as Ni-Mo / C-10:7-NS.

[0065] Material characterization Figure 1 The image shows the XRD pattern of the Ni-Mo bimetallic supported carbon material prepared in Example 1. As can be seen from the image, a series of obvious diffraction peaks are observed at 2θ of 23.5°, 31.5° and 38.0°. The positions of each diffraction peak are highly consistent with the characteristic peaks of the NiMoO4 standard card (PDF#12-0348), indicating that after solvothermal reaction and staged heat treatment, the nickel and molybdenum precursors were successfully transformed into the NiMoO4 crystalline phase, rather than forming a simple physical mixture of Ni, NiO or MoO3. This confirms that Ni and Mo have achieved effective chemical bonding and uniform composite at the atomic level.

[0066] Application Example 1 Performance testing and liquid phase product analysis of HER, OER and HMFOR in a three-electrode system To examine the electrocatalytic performance of the Ni-Mo / C catalyst obtained in the examples in the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and 5-hydroxymethylfurfural oxidation reaction (HMFOR), a three-electrode system was used for testing, and the HMFOR products were analyzed by liquid chromatography.

[0067] 1. Testing System The electrode preparation process is as follows: 5 mg of Ni-Mo / C catalyst was weighed, and 1000 μL of a mixed solvent of deionized water and anhydrous ethanol (volume ratio 3:1) and 30 μL of 5 wt% Nafion solution were added. The mixture was ultrasonically dispersed for 30 min to obtain a uniform slurry. 10 μL of the slurry was then pipetted onto the surface of a glassy carbon electrode with a diameter of 3 mm (geometric area 0.071 cm²). 2 After natural drying, it is used as a working electrode.

[0068] The test used a three-electrode system, with a glassy carbon electrode supported on the catalyst as the working electrode, an Hg / HgO electrode as the reference electrode, and a graphite rod as the counter electrode. The test was conducted at room temperature, and all potentials were converted to potentials relative to the reversible hydrogen electrode (RHE). The conversion formula is: E(RHE) = E(Hg / HgO) + 0.098 + 0.059 × pH.

[0069] 2. Linear Scan Voltammetry (LSV) Test The HER assay used 1M KOH as the electrolyte. Before the assay, high-purity nitrogen gas was bubbled into the electrolyte for 20 min to remove dissolved oxygen. The polarization curves were recorded using linear sweep voltammetry at a scan rate of 5 mV / s and a scan range of 0 V to -0.6 V (vs. RHE). The obtained HER polarization curves and Tafel curves are shown below. Figure 2 The results showed that the HER catalytic activity of catalysts with different Ni / Mo atomic ratios varied significantly, with the Ni / Mo atomic ratio of Example 1 being the most efficient at 10 mA / cm². 2 The overpotential at the current density was only 86 mV, and the Tafel slope was 96.18 mV / dec. For Examples 2-5, the catalysts with Ni / Mo atomic ratios of 1:1, 9:8, 11:6, and 7:10 had corresponding overpotentials of 404 mV, 341 mV, 288 mV, and 414 mV, respectively. The Tafel slopes for Examples 1-5 were 96.18 mV / dec, 100.06 mV / dec, 114.65 mV / dec, 108.7 mV / dec, and 102.92 mV / dec, respectively, indicating that the optimal hydrogen evolution catalytic performance was obtained at a Ni / Mo atomic ratio of 10:7. OER testing was performed using 1M KOH as the electrolyte, employing linear sweep voltammetry at a scan rate of 5 mV / s and a scan range of 1.0 V to 1.8 V (vs. RHE). At 10 mA / cm²... 2 At the given current density, the OER overpotential in Example 1 was 309 mV, and the Tafel slope was 98.92 mV / dec. At 20 mA / cm², 2 At the current density, the overpotential of OER is 336mV.

[0070] The HMFOR test used a 1M KOH solution containing 10mM 5-HMF as the electrolyte, and the test conditions were the same as those for OER. At 10mA / cm 2 At the given current density, the overpotential of HMFOR in Example 1 was 270 mV, a decrease of 39 mV compared to the corresponding potential of OER, with a Tafel slope of 92.45 mV / dec. At 20 mA / cm² 2 At the specified current density, the overpotential of HMFOR is 305 mV, indicating that this catalyst exhibits good electrocatalytic activity for the oxidation of 5-HMF. The polarization curves and Tafel curves of OER and HMFOR are shown below. Figure 3 (a) ~ (c).

[0071] Figure 3(d) Electrochemical impedance spectroscopy (Nyquist plot) of the Ni-Mo bimetallic supported carbon material prepared in Example 1 was measured in 1M KOH solution and 1M KOH solution containing 10mM 5-HMF, respectively. The test results show that the intercepts of the two curves in the high-frequency region are basically coincident with the real axis, indicating that the solution resistances of the two systems are similar. The addition of 5-HMF had no significant effect on the overall conductivity of the 1MKOH electrolyte; however, there was a significant difference in the semicircle diameters of the two curves. The black curve, representing the oxygen evolution reaction (OER) in the pure KOH system, had a larger semicircle diameter, while the red curve, representing the 5-hydroxymethylfurfural oxidation reaction (HMFOR) in the 5-HMF-containing system, had a significantly smaller semicircle diameter. This indicates that the charge transfer resistance of the HMFOR process is much lower than that of the OER process. This result directly proves that the Ni-Mo bimetallic supported carbon material prepared in this invention has excellent electrocatalytic activity for HMFOR, can effectively reduce the energy barrier of the HMF oxidation reaction, and accelerate the interfacial charge transfer process. It also verifies that the kinetics of the HMF oxidation reaction are significantly better than those of the oxygen evolution reaction, providing a solid electrochemical basis for the efficient electrocatalytic oxidation of 5-hydroxymethylfurfural coupled with hydrogen production at a lower cell voltage.

[0072] 2. Electrochemical active area test To further evaluate the electrochemical active area of ​​the Ni-Mo bimetallic supported carbon material prepared in Example 1, cyclic voltammetry tests were performed at scan rates of 20 mV / s, 40 mV / s, 60 mV / s, 80 mV / s, 100 mV / s, 120 mV / s, 160 mV / s, and 200 mV / s within the potential range where no significant Faraday reaction occurred. The double-layer capacitance (Cdl) of the catalyst was obtained by calculating half (ΔJ / 2) of the difference between the anodic and cathode current densities at different scan rates and then linearly fitting this difference to the scan rate. The test results showed that the double-layer capacitance of this catalyst in a 1 M KOH electrolyte containing 10 mM 5-HMF was 6.51 mF / cm². 2 A larger double-layer capacitance corresponds to a larger electrochemical active area, exposing more catalytic active sites and providing ample reaction space for efficient electrocatalytic reactions. Cyclic voltammetry curves and double-layer capacitance fitting results at different scan rates are shown below. Figure 4 .

[0073] 3. Analysis of liquid phase products from constant potential electrolysis at different voltages The Ni-Mo bimetallic supported carbon material prepared in Example 1 was used as the working electrode and placed in a 1M KOH electrolyte containing 10mM 5-HMF. Constant potential electrolysis was performed within a potential range of 1.48V to 1.60V (vs. RHE). After electrolysis to the same theoretical charge, samples were taken for analysis. The optimal reaction potential was determined to be 1.54V (vs. RHE). After electrolysis, liquid phase samples were collected, and the products were qualitatively and quantitatively analyzed using high-performance liquid chromatography (HPLC). The conversion rate of 5-HMF, the yield of 2,5-furandicarboxylic acid (FDCA), the product selectivity, and the reaction Faradaic efficiency were calculated based on the standard curve.

[0074] Test results showed that at the optimal potential of 1.54V (vs. RHE), both the FDCA yield and Faradaic efficiency reached 95.16%. HPLC analysis revealed that as the electrolysis reaction proceeded, the content of 5-HMF in the reaction system gradually decreased, while the content of the intermediate product 5-formyl-2-furanoic acid (FFCA) showed a trend of first increasing and then decreasing, whereas the content of the target product FDCA continuously increased. This indicates that 5-HMF can be converted into FDCA on the catalyst surface through a stepwise oxidation process. The comparison results of FDCA yield and Faradaic efficiency at different reaction potentials are shown in [Figure number missing]. Figure 5 .

[0075] 4. Cyclic stability test To investigate the long-term cycling stability of the Ni-Mo bimetallic supported carbon material prepared in Example 1, three consecutive potentiostatic electrolysis experiments were conducted using the same working electrode at the optimal reaction potential of 1.54 V (vs. RHE). Liquid products were collected after each electrolysis cycle for quantitative analysis by high-performance liquid chromatography (HPLC). The results showed that the FDCA yields for the first, second, and third cycles were 95.16%, 94.71%, and 94.26%, respectively, with corresponding Faradaic efficiencies of 95.16%, 94.71%, and 94.26%. After three consecutive cycles, the FDCA yield and Faradaic efficiency showed only a slight decrease and remained above 94%, indicating that the catalyst possesses excellent structural stability and catalytic activity retention during the electrocatalytic oxidation of 5-hydroxymethylfurfural. The changes in FDCA yield and Faradaic efficiency after three consecutive electrolysis cycles are shown in [Figure number missing]. Figure 6 .

[0076] To further investigate the catalytic stability and product conversion characteristics of the Ni-Mo bimetallic supported carbon material prepared in Example 1 during long-term reaction, a long-term constant-potential electrolysis experiment was conducted at the optimal reaction potential of 1.54 V (vs. RHE), and liquid phase samples were periodically collected for high-performance liquid chromatography (HPLC) analysis during the electrolysis process. The test results showed that with the extension of electrolysis time, 5-HMF could be almost completely converted into the target product 2,5-furandicarboxylic acid (FDCA). The yield and Faradaic efficiency of FDCA remained at a high level throughout the electrolysis process, while only a small amount of the intermediate product 5-formyl-2-furandicarboxylic acid (FFCA) was detected in the reaction system. This result indicates that the Ni-Mo bimetallic supported carbon material prepared in this invention can maintain stable catalytic activity during long-term electrocatalytic reactions. While efficiently undergoing hydrogen evolution reaction at the cathode, it can efficiently and selectively convert 5-HMF at the anode into FDCA, with low accumulation of intermediate products and a clear reaction conversion pathway. The concentration changes of 5-HMF, FFCA, and FDCA during long-term constant-potential electrolysis are shown in [Figure number missing]. Figure 7 .

[0077] Application Example 2 Comparison of LSV performance between HMFOR-HER coupling system and traditional OER-HER system in two-electrode configuration To verify the energy-saving effect of the catalyst of this invention in a real two-electrode electrolysis system, a glassy carbon electrode-based two-electrode system was constructed, and the linear sweep voltammetry (LSV) curves of the traditional oxygen evolution reaction coupled with hydrogen evolution reaction (OER-HER) and the 5-hydroxymethylfurfural oxidation reaction coupled with hydrogen evolution reaction (HMFOR-HER) were compared.

[0078] Electrode preparation Weigh 5 mg of the Ni-Mo / C catalyst prepared in Example 1 into a 1.5 mL centrifuge tube, add 1000 μL of a mixed solvent of deionized water and anhydrous ethanol (volume ratio 3:1), then add 30 μL of 5 wt% Nafion solution, and ultrasonically disperse for 30 min to form a uniform catalyst slurry. Use a pipette to take 10 μL of the above slurry and uniformly drop it onto the pretreated glassy carbon electrode (diameter 3 mm, geometric area 0.071 cm²). 2 The catalyst thin layer is formed on the surface after natural drying. Two identical loaded electrodes are prepared and used as the anode and cathode, respectively.

[0079] Electrolysis system construction System A is a traditional OER-HER system, with a 1M KOH solution without 5-HMF as the electrolyte. Oxygen evolution reaction occurs at the anode and hydrogen evolution reaction occurs at the cathode. System B is an HMFOR-HER system, with an electrolyte of 1M KOH solution containing 10mM 5-HMF. The 5-HMF oxidation reaction occurs at the anode, and the hydrogen evolution reaction occurs at the cathode.

[0080] Electrochemical testing Linear sweep voltammetry was performed using a CHI 760E electrochemical workstation in two-electrode mode. Two glassy carbon electrodes loaded with Ni-Mo / C catalyst were inserted into the electrolyte as the anode and cathode, respectively, without a reference electrode. The scan rate was 5 mV / s, the scan range was 1.0 V to 2.2 V, and the current density was based on the geometric area of ​​the glassy carbon electrode being 0.071 cm². 2 Normalization was performed, and all tests were conducted at room temperature. The two-electrode LSV comparison curves for the OER-HER and HMFOR-HER systems are shown below. Figure 8 .

[0081] Results and Discussion like Figure 8 As shown, at the same current density, the electrolysis voltage required for system B (HMFOR-HER) is significantly lower than that for system A (OER-HER). Specifically, when the current density is 10 mA / cm², the electrolysis voltage required for system B (HMFOR-HER) is significantly lower than that required for system A (OER-HER). 2 At this time, system A requires a voltage of 1.831V, and system B requires a voltage of 1.772V, a voltage drop of approximately 59mV; when the current density is 20mA / cm²... 2 At that time, the required voltage for system A was 1.936V, and the required voltage for system B was 1.873V, a voltage reduction of approximately 63mV. This result is consistent with the decreasing anode potential trend exhibited by HMFOR compared to OER in the three-electrode system, indicating that replacing the traditional oxygen evolution reaction with the 5-HMF oxidation reaction as the anode reaction can significantly reduce the cell voltage of the overall electrolysis system and effectively reduce electrolysis energy consumption. Combined with the aforementioned test results, it can be seen that the Ni-Mo / C catalyst prepared in this invention can simultaneously serve as a highly efficient catalyst for both the cathode hydrogen evolution reaction and the anode 5-HMF oxidation reaction, and is suitable for HMFOR-HER coupled electrolysis systems.

[0082] To further verify the impact of each process step of the present invention on catalyst performance, the Ni-Mo / C catalyst obtained in Example 1 was compared with the single-metal Ni / C catalyst of Comparative Example 1, the single-metal Mo / C catalyst of Comparative Example 2, the Ni-Mo / C catalyst prepared with carbon support without nitric acid pretreatment of Comparative Example 3, the Ni-Mo / C catalyst prepared with carbon support pretreated with hydrochloric acid of Comparative Example 4, and the Ni-Mo / C catalyst prepared with non-segmented heat treatment of Comparative Example 5. The key performance parameters of each catalyst are shown in Table 1. Table 1

[0083] Comparative results show that neither the single-metal Ni / C nor Mo / C catalysts can simultaneously achieve excellent 5-HMF oxidation activity and hydrogen evolution performance. Ni / C exhibits relatively good HMFOR activity but poor HER performance, while Mo / C shows relatively good HER performance but poor HMFOR activity. This clearly demonstrates that the bimetallic synergistic effect between Ni and Mo plays a crucial role in simultaneously improving the bifunctional catalytic performance of the catalysts for both HMFOR and HER. Compared to Example 1, the catalytic performance of both the untreated and hydrochloric acid-treated samples showed a significant decrease, with the untreated sample showing the most significant performance decline. This is because the strong oxidizing properties of nitric acid can efficiently introduce oxygen-containing functional groups such as hydroxyl and carboxyl groups onto the carbon support surface. These functional groups serve as anchoring sites for metal ions, promoting the uniform loading, dispersion, and stable binding of Ni and Mo components on the carbon support surface. Hydrochloric acid, lacking strong oxidizing properties, cannot effectively introduce sufficient oxygen-containing functional groups. Therefore, nitric acid pretreatment is indispensable in the carbon support surface functionalization step. Furthermore, the catalytic performance of the samples treated with non-segmented heat treatment also decreased, indicating that the staged heat treatment process used in this invention is beneficial for forming a stable and synergistically effective Ni-Mo bimetallic active structure, avoiding metal particle agglomeration and loss of active sites caused by single high-temperature heat treatment.

[0084] In summary, the Ni-Mo bimetallic supported carbon material prepared in the embodiments of this invention is a highly efficient HMFOR-HER catalyst. It exhibits excellent catalytic performance and long-term stability under alkaline conditions, providing a high-performance catalyst for the low-cost, green, and efficient simultaneous production of hydrogen and bio-based high-value chemicals. It plays a positive supporting role in promoting the industrialization of green hydrogen and assisting in the clean energy transition.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a Ni-Mo bimetallic supported carbon material, characterized in that, Includes the following steps: S1, add the carbon support to the nitric acid solution, impregnate, separate the solid and liquid, wash, and dry to obtain the pretreated carbon support; S2, the pretreated carbon support is dispersed in ethylene glycol, a nickel source and a molybdenum source are added, the pH of the system is adjusted to alkaline with ammonia, and a solvothermal reaction is carried out by heating to obtain a nickel-molybdenum-carbon composite. S3, the nickel-molybdenum-carbon composite is subjected to staged heat treatment under an inert atmosphere to obtain Ni-Mo bimetallic supported carbon material.

2. The method for preparing Ni-Mo bimetallic supported carbon material as described in claim 1, characterized in that, In S1, the carbon support is Vulcan XC-72 carbon black; and / or In S1, the mass-to-volume ratio of the carbon support to the nitric acid solution is 1 g:(20~80) mL; the concentration of the nitric acid solution is 1 mol / L~3 mol / L; and / or In S1, the impregnation temperature is 20℃~40℃, and the reaction time is 24h~48h.

3. The method for preparing Ni-Mo bimetallic supported carbon material as described in claim 1, characterized in that, In S2, the nickel source is nickel nitrate, and the molybdenum source is ammonium molybdate.

4. The method for preparing Ni-Mo bimetallic supported carbon material as described in claim 1, characterized in that, In S2, the mass-to-volume ratio of the pretreated carbon support to ethylene glycol is 1 g: (30~80) mL; and / or In S2, the mass ratio of the pretreated carrier to the nickel source is 1:(1~1.6); and / or In S2, the atomic molar ratio of Ni in the nickel source to Mo in the molybdenum source is (0.7~1.85):

1.

5. The method for preparing Ni-Mo bimetallic supported carbon material as described in claim 1 or 4, characterized in that, In S2, alkalinity refers to a pH value of 10-11; and / or In S2, the temperature of the solvothermal reaction is 100℃~130℃, and the reaction time is 20h~28h.

6. The method for preparing Ni-Mo bimetallic supported carbon material as described in claim 1, characterized in that, In S3, the staged heat treatment specifically includes the following steps: First, raise the temperature to 150℃~250℃ at a rate of 1℃ / min~5℃ / min and hold for 0.5h~1h. Then, raise the temperature to 400℃~500℃ at a rate of 1℃ / min~5℃ / min and hold for 0.5h~1h.

7. A Ni-Mo bimetallic supported carbon material, characterized in that, It is prepared by the method for preparing Ni-Mo bimetallic supported carbon material according to any one of claims 1 to 6.

8. An electrode, characterized in that, Including the Ni-Mo bimetallic supported carbon material as described in claim 7.

9. The application of the Ni-Mo bimetallic supported carbon material of claim 7 or the electrode of claim 8 in the electrocatalytic oxidation of 5-hydroxymethylfurfural coupled to produce hydrogen.

10. A method for electrocatalytic oxidation of 5-hydroxymethylfurfural coupled with hydrogen production, characterized in that, The process includes the following steps: using a two-electrode system, with the Ni-Mo bimetallic supported carbon material serving as both the anode and cathode as the electrocatalytic active components, placing the anode and cathode in an alkaline electrolyte containing 5-hydroxymethylfurfural, applying a voltage between the two electrodes to carry out an electrocatalytic oxidation reaction, oxidizing 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid at the anode, and simultaneously generating hydrogen gas at the cathode.

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