Mesoporous scandium oxide material, preparation method and application thereof

Abstract

This invention provides a mesoporous scandium oxide material, its preparation method, and its application. Using mesoporous silica as a template, scandium nitrate hydrate is used to fill the pores of the mesoporous silica to obtain metal nitrate@mesoporous silica. The metal nitrate@mesoporous silica is then calcined to obtain a metal oxide@mesoporous silica composite. Sodium hydroxide is added to the metal oxide@mesoporous silica composite to remove silica, yielding the mesoporous scandium oxide material. This mesoporous scandium oxide material possesses a stable mesoporous structure and high specific surface area, providing more active sites for the reaction, lowering the reaction energy barrier, and increasing the reaction rate. The preparation method of the mesoporous scandium oxide material provided in this application is simple, uses inexpensive and readily available raw materials, and the preparation process is green, environmentally friendly, and pollution-free. It has high application value and broad application prospects in the field of electrocatalytic oxidation of 5-hydroxymethylfurfural, and is also suitable for industrial applications.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology, and specifically relates to a mesoporous scandium oxide material, its preparation method, and its application. Background Technology

[0002] The high-value conversion of biomass organic solid waste has become a hot research topic. Among them, 2,5-furandicarboxylic acid (FDCA), obtained by catalytic oxidation of the biomass-derived molecule 5-hydroxymethylfurfural (HMF), can serve as a new monomer for bio-based plastics. Compared with traditional petroleum-based plastics, the use of bio-based plastics can not only reduce dependence on fossil resources, but also reduce pollution and carbon emissions, and achieve synergistic efficiency, meeting the sustainable development requirements of a green economy.

[0003] Traditional thermodynamic catalytic oxidation of HMF to FDCA has yielded some successes, especially when using noble metals (Au, Ag, Pt, Pd, etc.) as catalysts, achieving FDCA yields as high as 99%. However, this often requires stringent reaction conditions, such as high reaction temperatures (≥60℃) and high reaction pressures (up to 10 bar O2). Electrocatalytic oxidation of HMF to FDCA offers advantages such as being green and pollution-free, having mild reaction conditions, low cost, and simple and convenient operation. Noble metal catalysts (Au, Ag, Pt, etc.) are highly efficient catalysts for the electrocatalytic oxidation of HMF to FDCA due to their superior catalytic activity and high product selectivity; however, the scarcity and high price of noble metals hinder further large-scale production. Therefore, developing efficient, stable, and low-cost non-noble metal catalysts or catalysts with low noble metal content has always been a research focus. Scandium oxide is a transition metal oxide that is widely used in alloys, novel electric light source materials, laser materials, catalysts, and ceramics due to its wide availability, low cost, and unique physicochemical properties. However, commercially available scandium oxide generally has a small specific surface area, which limits its contact area with reactants during catalysis, thus limiting its application in the field of catalysts.

[0004] Therefore, how to provide a mesoporous scandium oxide material with a high specific surface area, which can efficiently electrocatalyze the oxidation of HMF to prepare FDCA, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a mesoporous scandium oxide material, its preparation method, and its application, so as to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for preparing mesoporous scandium oxide materials, the method comprising the following steps: S1. Add triblock copolymer P123 to deionized water and mix thoroughly to obtain solution A; add concentrated hydrochloric acid to solution A and stir to dissolve at 30-40°C to obtain solution B; add n-butanol to solution B and continue stirring for 1 hour, then add tetraethyl orthosilicate and stir at 400-600 rpm / min for 24 hours to obtain solution C; transfer solution C to a polypropylene container and carry out a hydrothermal reaction in an oven to obtain a reaction mixture, wherein the mass ratio of triblock copolymer P123 to deionized water, concentrated hydrochloric acid, n-butanol, and tetraethyl orthosilicate is 1:(20-50):(1-10):(1-10):(1-10); filter and dry to obtain a solid product; calcine the solid product to obtain a mesoporous silica template; S2. Dissolve scandium nitrate hydrate in ethanol to obtain solution D; add the mesoporous silica template to solution D and stir evenly to obtain a metal nitrate@mesoporous silica mixed solution E, wherein the mass ratio of the mesoporous silica template to the scandium nitrate hydrate and the ethanol is 1:(1-5):(3-10); dry and grind the mixed solution E to obtain a metal nitrate@mesoporous silica composite. S3. Calcining the metal nitrate@mesoporous silica composite to obtain a metal oxide@mesoporous silica composite. S4. The metal oxide@mesoporous silica composite is transferred to a polypropylene container, sodium hydroxide solution is added at room temperature, the temperature is raised to 70-90°C and stirring is continued for 24 hours. After stirring is completed, the mixture is cooled to room temperature, centrifuged and dried to obtain the precipitate. S5. Transfer the precipitate to a polypropylene container and repeat step S4 three times to obtain mesoporous scandium oxide material.

[0007] In the first aspect, the step of transferring the solution C to a polypropylene container and carrying out a hydrothermal reaction in an oven to obtain a reaction mixture specifically includes: transferring the solution C to a polypropylene container and sealing it for storage; placing the polypropylene container in an oven and carrying out a hydrothermal reaction at a temperature of 40–120°C for 24 hours; and after the reaction is completed, cooling the polypropylene container to room temperature to obtain the reaction mixture.

[0008] In the first aspect, in step S1, the calcination conditions include: the calcination heating rate is 1-3°C / min; the calcination temperature is 500-600°C; and the calcination time is 6 hours.

[0009] In the first aspect, in step S2, the drying conditions include: the drying temperature is 50°C; and the drying time is 12 hours.

[0010] In the first aspect, in step S3, the calcination conditions include: the calcination heating rate is 1-3°C / min; the calcination temperature is 500-700°C; and the calcination time is 2 hours.

[0011] In the first aspect, in step S4, the concentration of the sodium hydroxide solution is 1 to 5 mol / L; the volume of the sodium hydroxide solution added is 50 mL.

[0012] In the first aspect, in step S4, the stirring rate of the stirring is 400 to 600 rpm / min.

[0013] In the first aspect, in step S4, the drying conditions include: the drying temperature is 60–100°C; and the drying time is 12–24 hours.

[0014] A second aspect of this invention provides a mesoporous scandium oxide material, prepared by the method described in the first aspect; the specific surface area of ​​the mesoporous scandium oxide material is 110–220 m². 2 / g, the average pore size of the mesoporous scandium oxide material is 3-10 nm, and the pore volume of the mesoporous scandium oxide material is 0.3-1.2 cm³. 3 / g.

[0015] The third aspect of this invention provides an application of a mesoporous scandium oxide material, wherein the step of electrocatalytically oxidizing 5-hydroxymethylfurfural using the mesoporous scandium oxide material includes: The ground mesoporous scandium oxide material was added to a mixed solution of ethanol and Nafion solution and ultrasonically treated to obtain a homogeneous solution. The homogeneous solution was then dropped onto nickel foam and dried at room temperature to obtain scandium oxide / nickel foam. An H-type electrolytic cell was assembled, using scandium oxide / nickel foam as the working electrode, Hg / HgO as the reference electrode, and platinum wire as the counter electrode. A pretreated Nafion-117 ion exchange membrane was used to separate the cathode chamber and the anode chamber. The electrolyte in the cathode chamber was a 1 mol / L potassium hydroxide solution, and the electrolyte in the anode chamber was a mixed solution of a 1 mol / L potassium hydroxide solution and a 10 mmol / L 5-hydroxymethylfurfural solution. After assembly, a voltage is applied to the H-type electrolytic cell to complete the electrocatalytic oxidation of 5-hydroxymethylfurfural; The mesoporous scandium oxide material is the mesoporous scandium oxide material described in the second aspect.

[0016] Beneficial effects: This invention provides a method for preparing mesoporous scandium oxide material. First, a mesoporous silica template is prepared using triblock copolymer P123, deionized water, concentrated hydrochloric acid, n-butanol, and tetraethyl orthosilicate as raw materials to provide a mesoporous structure for the material. Second, scandium nitrate hydrate is filled into the pores of the mesoporous silica template, and the resulting metal nitrate@mesoporous silica mixed solution is dried and ground to obtain dry, small-particle-size metal nitrate@mesoporous silica, thereby increasing the specific surface area of ​​the metal nitrate@mesoporous silica. Then, the nitrate@mesoporous silica is calcined at high temperature, where the nitrate is oxidized and decomposed to obtain a metal oxide, thus yielding a metal oxide@mesoporous silica composite. Finally, sodium hydroxide is reacted with silica to remove the silica from the metal oxide@mesoporous silica composite. To ensure complete removal of silica, sodium hydroxide solution is reacted with the precipitate multiple times, resulting in a mesoporous scandium oxide material free of silica. In other words, this application uses mesoporous silica as a template, fills the pores of mesoporous silica with scandium nitrate hydrate to obtain metal nitrate@mesoporous silica, calcines the metal nitrate@mesoporous silica to obtain a metal oxide@mesoporous silica composite, and adds sodium hydroxide to the metal oxide@mesoporous silica composite to remove silica, thereby obtaining mesoporous scandium oxide material. The preparation method of the mesoporous scandium oxide material provided in this application is simple, the raw materials are inexpensive and readily available, and the preparation process is green, environmentally friendly, and pollution-free. It has high application value and broad application prospects in the field of electrocatalytic oxidation of 5-hydroxymethylfurfural technology, and is also suitable for industrial application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 The nitrogen adsorption-desorption curves for the mesoporous scandium oxide material in Example 1 of this application are shown. Figure 2 Linear sweep voltammetry (LSV) plot of the scandium oxide / nickel foam working electrode in Example 1 of this application; Figure 3 This is the X-ray diffraction (XRD) pattern of the mesoporous scandium oxide material in Example 2 of this application; Figure 4 The graph shows the yield and Faraday efficiency of HMF electrolysis at different voltages using the scandium oxide / nickel foam working electrode in Example 2 of this application. Figure 5This is a scanning electron microscope (SEM) image of the mesoporous scandium oxide material in Example 3 of this application; Figure 6 This is a graph showing the yield and Faraday efficiency of the scandium oxide / nickel foam working electrode after 6 cycles of electrolysis in Example 3 of this application; Figure 7 This is a scanning electron microscope (SEM) image of the scandium oxide / nickel foam working electrode in Example 3 of this application after cyclic electrolysis of HMF. Detailed Implementation

[0019] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making the advantages and various effects of the present invention more clearly apparent. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the present invention.

[0020] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0021] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be obtained by purchasing them from the market or by existing methods.

[0022] This application provides a method for preparing a mesoporous scandium oxide material, the method comprising the following steps: S1. Add triblock copolymer P123 to deionized water and mix thoroughly to obtain solution A; add concentrated hydrochloric acid to solution A and stir to dissolve at 30-40°C to obtain solution B; add n-butanol to solution B and continue stirring for 1 hour, then add tetraethyl orthosilicate and stir at 400-600 rpm / min for 24 hours to obtain solution C; transfer solution C to a polypropylene container and carry out a hydrothermal reaction in an oven to obtain a reaction mixture, wherein the mass ratio of triblock copolymer P123 to deionized water, concentrated hydrochloric acid, n-butanol, and tetraethyl orthosilicate is 1:(20-50):(1-10):(1-10):(1-10); filter and dry to obtain a solid product; calcine the solid product to obtain a mesoporous silica template; S2. Dissolve scandium nitrate hydrate in ethanol to obtain solution D; add the mesoporous silica template to solution D and stir evenly to obtain a metal nitrate@mesoporous silica mixed solution E, wherein the mass ratio of the mesoporous silica template to the scandium nitrate hydrate and the ethanol is 1:(1-5):(3-10); dry and grind the mixed solution E to obtain a metal nitrate@mesoporous silica composite. S3. Calcining the metal nitrate@mesoporous silica composite to obtain a metal oxide@mesoporous silica composite. S4. The metal oxide@mesoporous silica composite is transferred to a polypropylene container, sodium hydroxide solution is added at room temperature, the temperature is raised to 70-90°C and stirring is continued for 24 hours. After stirring is completed, the mixture is cooled to room temperature, centrifuged and dried to obtain the precipitate. S5. Transfer the precipitate to a polypropylene container and repeat step S4 three times to obtain mesoporous scandium oxide material.

[0023] Specifically, the present invention provides a method for preparing mesoporous scandium oxide material. First, a mesoporous silica template is prepared using triblock copolymer P123, deionized water, concentrated hydrochloric acid, n-butanol, and tetraethyl orthosilicate as raw materials to provide a mesoporous structure for the material. Second, scandium nitrate hydrate is filled into the pores of the mesoporous silica template, and the resulting metal nitrate@mesoporous silica mixed solution is dried and ground to obtain dry, small-particle-size metal nitrate@mesoporous silica, thereby increasing the specific surface area of ​​the metal nitrate@mesoporous silica. Then, the nitrate@mesoporous silica is calcined at high temperature, where the nitrate is oxidized and decomposed to obtain a metal oxide, thus obtaining a metal oxide@mesoporous silica composite. Finally, sodium hydroxide is reacted with silica to remove the silica from the metal oxide@mesoporous silica composite. To ensure complete removal of silica, sodium hydroxide solution is reacted with the precipitate multiple times to obtain a mesoporous scandium oxide material free of silica. In other words, this application uses mesoporous silica as a template, fills the pores of mesoporous silica with scandium nitrate hydrate to obtain metal nitrate@mesoporous silica, calcines the metal nitrate@mesoporous silica to obtain a metal oxide@mesoporous silica composite, and adds sodium hydroxide to the metal oxide@mesoporous silica composite to remove silica, thereby obtaining mesoporous scandium oxide material. The preparation method of the mesoporous scandium oxide material provided in this application is simple, the raw materials are inexpensive and readily available, and the preparation process is green, environmentally friendly, and pollution-free. It has high application value and broad application prospects in the field of electrocatalytic oxidation of 5-hydroxymethylfurfural technology, and is also suitable for industrial application.

[0024] In some possible embodiments, the step of transferring the solution C to a polypropylene container and carrying out a hydrothermal reaction in an oven to obtain the reaction mixture specifically includes: transferring the solution C to a polypropylene container and sealing it for storage; placing the polypropylene container in an oven and carrying out a hydrothermal reaction at a temperature of 40–120°C for 24 hours; after the reaction is completed, cooling the polypropylene container to room temperature to obtain the reaction mixture.

[0025] In some possible embodiments, in step S1, the calcination conditions include: the calcination heating rate is 1-3°C / min; the calcination temperature is 500-600°C; and the calcination time is 6 hours.

[0026] In step S1, in order to purify the mesoporous silica, the solid product is calcined, and the calcination temperature is set to 500-600℃, the heating rate is 1-3℃ / min, and the calcination time is 6h. Through calcination, the triblock copolymer P123, small molecule compounds and solvents are removed, so that the obtained mesoporous silica template has high purity and contains almost no impurities.

[0027] In some possible embodiments, in step S2, the drying conditions include: the drying temperature is 50°C; and the drying time is 12 hours.

[0028] In step S2, scandium nitrate hydrate is uniformly dispersed in the pores of the mesoporous silica template using ethanol. After uniform dispersion, the temperature is raised to 50°C and dried for 12 hours. The ethanol is then removed to obtain a dried metal nitrate@mesoporous silica composite, which is then thoroughly ground to reduce the calcination time in the next step.

[0029] In some possible embodiments, in step S3, the calcination conditions include: the calcination heating rate is 1-3°C / min; the calcination temperature is 500-700°C; and the calcination time is 2 hours.

[0030] In step S3, in order to ensure that the metal nitrate can be completely oxidized and decomposed into metal oxide, in a specific embodiment, the heating rate of calcination is set to 1-3℃ / min, the calcination temperature is set to 500-700℃, and the calcination time is set to 2h.

[0031] In some possible embodiments, in step S4, the concentration of the sodium hydroxide solution is 1-5 mol / L; and the volume of the sodium hydroxide solution added is 50 mL.

[0032] In step S4, in order to remove silica from the metal oxide@mesoporous silica composite, 50 mL of 1-5 mol / L sodium hydroxide solution is added to the composite. Sodium hydroxide reacts with silica to generate sodium silicate and water, thereby removing silica and obtaining high-purity mesoporous scandium oxide material.

[0033] In some possible embodiments, in step S4, the stirring rate is 400–600 rpm / min.

[0034] Because the metal oxide@mesoporous silica composite contains pores, the stirring speed is set to 400-600 rpm / min in order to fully remove silica from the pores of the composite.

[0035] In some possible embodiments, in step S4, the drying conditions include: the drying temperature is 60–100°C; and the drying time is 12–24 hours.

[0036] Based on a general inventive concept, this application also provides a mesoporous scandium oxide material, prepared by the method for preparing mesoporous scandium oxide material described in the first aspect; the specific surface area of ​​the mesoporous scandium oxide material is 110–220 m². 2 / g, the average pore size of the mesoporous scandium oxide material is 3-10 nm, and the pore volume of the mesoporous scandium oxide material is 0.3-1.2 cm³. 3 / g.

[0037] The mesoporous scandium oxide material prepared by the method of the first aspect has a high specific surface area and a stable mesoporous structure, which can provide more active sites for catalytic reactions, reduce the reaction energy barrier, and improve the catalytic reaction efficiency.

[0038] Based on a general inventive concept, this application also provides an application of a mesoporous scandium oxide material, wherein the step of electrocatalytically oxidizing 5-hydroxymethylfurfural using the mesoporous scandium oxide material includes: The ground mesoporous scandium oxide material was added to a mixed solution of ethanol and Nafion solution and ultrasonically treated to obtain a homogeneous solution. The homogeneous solution was then dropped onto nickel foam and dried at room temperature to obtain scandium oxide / nickel foam. An H-type electrolytic cell was assembled, using scandium oxide / nickel foam as the working electrode, Hg / HgO as the reference electrode, and platinum wire as the counter electrode. A pretreated Nafion-117 ion exchange membrane was used to separate the cathode chamber and the anode chamber. The electrolyte in the cathode chamber was a 1 mol / L potassium hydroxide solution, and the electrolyte in the anode chamber was a mixed solution of a 1 mol / L potassium hydroxide solution and a 10 mmol / L 5-hydroxymethylfurfural solution. After assembly, a voltage is applied to the H-type electrolytic cell to complete the electrocatalytic oxidation of 5-hydroxymethylfurfural; The mesoporous scandium oxide material is the mesoporous scandium oxide material described in the second aspect.

[0039] Specifically, this application describes the preparation of a novel mesoporous scandium oxide material and its electrocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid, thereby achieving high-value conversion of biomass organic solid waste and reducing dependence on fossil resources. Furthermore, the preparation method of the mesoporous scandium oxide material is simple, the raw materials are readily available, and it can be produced on a large scale. The prepared mesoporous scandium oxide material has a high specific surface area and a specific pore structure, providing more active sites for the catalytic oxidation of 5-hydroxymethylfurfural, lowering the reaction energy barrier, and increasing the reaction rate. Simultaneously, the pore structure of the mesoporous scandium oxide material remains almost unchanged after electrolysis, indicating that the mesoporous scandium oxide material possesses excellent stability and high catalytic activity.

[0040] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0041] Example 1

[0042] (1) 6g of triblock copolymer P123 was added to 220mL of deionized water and mixed evenly to obtain solution A. 10mL of concentrated hydrochloric acid was added to solution A and stirred at 35℃ until the triblock copolymer P123 was completely dissolved to obtain solution B. 10g of n-butanol was added to solution B and stirred for 1h. 15g of tetraethyl orthosilicate (TEOS) was added and stirred at 35℃ at a stirring speed of 500 rpm / min for 24h to obtain solution C. Solution C was transferred to a polypropylene container and sealed for storage. The polypropylene container was placed in an oven and hydrothermally reacted at 100℃ for 24h. After the reaction was completed, the polypropylene container was cooled to room temperature to obtain the reaction mixture. The reaction mixture was filtered and dried to obtain a solid product. The solid product was calcined at 500℃ for 6h at a heating rate of 2℃ / min. After calcination, a mesoporous silica template was obtained. (2) Dissolve 0.5g scandium nitrate hydrate in 3mL ethanol to obtain solution D. Add 0.6g of the mesoporous silica template from step (1) to solution D and stir evenly to obtain a mixed solution E of metal nitrate@mesoporous silica. Then place the mixed solution E in a 50℃ oven and dry for 12h to remove the solvent and obtain the complex. Grind the complex to obtain the metal nitrate@mesoporous silica complex. (3) The metal nitrate@mesoporous silica composite was calcined at 550°C for 2 hours with a heating rate of 2°C / min. After calcination, the metal oxide@mesoporous silica composite was obtained. (4) The metal oxide@mesoporous silica composite was transferred to a polypropylene container, and 50 mL of 2 mol / L sodium hydroxide solution was added at room temperature. The mixture was stirred at 80 °C at a stirring speed of 500 rpm / min for 24 h. After stirring, the mixture was cooled to room temperature, centrifuged, and dried at 60 °C for 24 h to obtain the precipitate. (5) Transfer the precipitate to a polypropylene container and repeat step (4) three times to finally obtain mesoporous scandium oxide material.

[0043] An application of a mesoporous scandium oxide material involves the electrocatalytic oxidation of 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid using the mesoporous scandium oxide material in step (5). The specific steps include: 2 mg of ground mesoporous scandium oxide material was added to a mixture of 900 μL ethanol and 100 μL Nafion solution, and sonicated to obtain a homogeneous solution. The homogeneous solution was dropped onto 1×1 cm nickel foam and dried at room temperature to obtain scandium oxide / nickel foam. An H-type electrolytic cell was assembled, using scandium oxide / nickel foam as the working electrode, Hg / HgO as the reference electrode, and platinum wire as the counter electrode. A pretreated Nafion-117 ion exchange membrane was used to separate the cathode chamber and the anode chamber. The electrolyte in the cathode chamber was 5 mL of 1 mol / L potassium hydroxide solution, and the electrolyte in the anode chamber was a mixture of 5 mL of 1 mol / L potassium hydroxide solution and 10 mmol / L 5-hydroxymethylfurfural solution. After assembly, a voltage is applied to the H-type electrolytic cell to complete the electrocatalytic oxidation of 5-hydroxymethylfurfural.

[0044] Performance testing: Using the Gamry electrochemical workstation, linear sweep voltammetry (LSV) was performed with a three-electrode system in the voltage range of 0–0.7 V (vsHg / HgO) and a voltage sweep rate of 5 mV / s.

[0045] The mesoporous scandium oxide material obtained in step (5) was subjected to nitrogen adsorption-desorption tests. The results showed that the mesoporous scandium oxide material has a high specific surface area (216 m²). 2 / g), the pore size distribution is concentrated at around 4.3 nm, and from Figure 1 It can be seen that it conforms to the fourth type of adsorption curve, proving that the prepared scandium oxide belongs to the mesoporous material. Using scandium oxide / nickel foam as the working electrode, Hg / HgO as the reference electrode, and platinum wire as the counter electrode, as shown... Figure 2As shown in the LSV test, scandium oxide / nickel foam began to oxidize HMF at 1.35 V vsRHE, which is about 150 mV lower than the oxidation onset potential of OER. This indicates that scandium oxide is better than OER for the electrocatalytic oxidation of HMF, and requires less voltage at the same current density, thus exhibiting better catalytic effect.

[0046] Example 2

[0047] (1) Add 5g of triblock copolymer P123 to 150mL of deionized water and mix well to obtain solution A. Add 15mL of concentrated hydrochloric acid to solution A and stir at 30℃ until the triblock copolymer P123 is completely dissolved to obtain solution B. Add 15g of n-butanol to solution B and stir for 1h. Then add 20g of tetraethyl orthosilicate (TEOS) and stir at 30℃ for 24h at a stirring speed of 400 rpm / min to obtain solution C. Transfer solution C to a polypropylene container and seal it for storage. Place the polypropylene container in an oven and perform a hydrothermal reaction at 120℃ for 24h. After the reaction is completed, cool the polypropylene container to room temperature to obtain the reaction mixture. Filter and dry the reaction mixture to obtain a solid product. Calcine the solid product at 550℃ for 6h at a heating rate of 2℃ / min. After calcination, obtain a mesoporous silica template. (2) Dissolve 0.7g scandium nitrate hydrate in 4mL ethanol to obtain solution D. Add 0.5g of the mesoporous silica template from step (1) to solution D and stir evenly to obtain a mixed solution E of metal nitrate@mesoporous silica. Then place the mixed solution E in a 50℃ oven and dry for 12h to remove the solvent and obtain the complex. Grind the complex to obtain the metal nitrate@mesoporous silica complex. (3) The metal nitrate@mesoporous silica composite was calcined at 600℃ for 2h with a heating rate of 2℃ / min. After calcination, the metal oxide@mesoporous silica composite was obtained. (4) The metal oxide@mesoporous silica composite was transferred to a polypropylene container, and 50 mL of 3 mol / L sodium hydroxide solution was added at room temperature. The mixture was stirred at 75 °C at a stirring speed of 400 rpm / min for 24 h. After stirring, the mixture was cooled to room temperature, centrifuged, and dried at 80 °C for 18 h to obtain the precipitate. (5) Transfer the precipitate to a polypropylene container and repeat step (4) three times to finally obtain mesoporous scandium oxide material.

[0048] An application of a mesoporous scandium oxide material involves the electrocatalytic oxidation of 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid using the mesoporous scandium oxide material in step (5). The specific steps include: 4 mg of ground mesoporous scandium oxide material was added to a mixture of 900 μL ethanol and 100 μL Nafion solution, and sonicated to obtain a homogeneous solution. The homogeneous solution was dropped onto 1×2 cm nickel foam and dried at room temperature to obtain scandium oxide / nickel foam. An H-type electrolytic cell was assembled, using scandium oxide / nickel foam as the working electrode, Hg / HgO as the reference electrode, and platinum wire as the counter electrode. A pretreated Nafion-117 ion exchange membrane was used to separate the cathode chamber and the anode chamber. The electrolyte in the cathode chamber was 10 mL of 1 mol / L potassium hydroxide solution, and the electrolyte in the anode chamber was a mixture of 10 mL of 1 mol / L potassium hydroxide solution and 10 mmol / L 5-hydroxymethylfurfural solution. After assembly, a voltage is applied to the H-type electrolytic cell to complete the electrocatalytic oxidation of 5-hydroxymethylfurfural.

[0049] Performance testing: Using the Gamry electrochemical workstation, HMF electrolysis was tested at different voltages using a three-electrode system. When the charge reached 58C, the diluted sample was tested by high performance liquid chromatography. The corresponding FDCA yield, reaction Faraday efficiency, and carbon balance were calculated using the standard curve.

[0050] The mesoporous scandium oxide material obtained in step (5) was subjected to nitrogen adsorption-desorption tests. The results showed that the mesoporous scandium oxide material has a high specific surface area (156 m²). 2 The scandium oxide ( / g) has a pore size distribution concentrated around 5.1 nm and conforms to the IV type of adsorption curve, proving that the prepared scandium oxide belongs to the mesoporous material. Figure 3 XRD images of mesoporous scandium oxide were prepared, showing a strong agreement with the standard card (PDF #88-2159), confirming that the catalyst component was scandium oxide. Using scandium oxide / nickel foam as the working electrode, electrolysis was performed at five different voltages in HMF electrolysis tests. Figure 4 It can be seen that the yield of FDCA and the faradaic efficiency of the reaction are the highest at 1.46 V electrolysis, which are 92.4% and 90.2%, respectively, indicating that mesoporous scandium oxide has excellent catalytic performance for HMF oxidation at this voltage.

[0051] Example 3

[0052] (1) 7g of triblock copolymer P123 was added to 250mL of deionized water and mixed evenly to obtain solution A. 12mL of concentrated hydrochloric acid was added to solution A and stirred at 40℃ until the triblock copolymer P123 was completely dissolved to obtain solution B. 8g of n-butanol was added to solution B and stirred for 1h. 12g of tetraethyl orthosilicate (TEOS) was added and stirred at 40℃ for 24h at a stirring speed of 550 rpm / min to obtain solution C. Solution C was transferred to a polypropylene container and sealed for storage. The polypropylene container was placed in an oven and hydrothermally reacted at 80℃ for 24h. After the reaction was completed, the polypropylene container was cooled to room temperature to obtain the reaction mixture. The reaction mixture was filtered and dried to obtain a solid product. The solid product was calcined at 600℃ for 6h at a heating rate of 1℃ / min. After calcination, a mesoporous silica template was obtained. (2) Dissolve 1.0 g of scandium nitrate hydrate in 12 mL of ethanol to obtain solution D. Add 0.5 g of the mesoporous silica template from step (1) to solution D and stir evenly to obtain a mixed solution E of metal nitrate@mesoporous silica. Then place the mixed solution E in a 50 °C oven and dry for 12 h to remove the solvent and obtain the complex. Grind the complex to obtain the metal nitrate@mesoporous silica complex. (3) The metal nitrate@mesoporous silica composite was calcined at 650℃ for 2h with a heating rate of 1℃ / min. After calcination, the metal oxide@mesoporous silica composite was obtained. (4) The metal oxide@mesoporous silica composite was transferred to a polypropylene container, and 50 mL of 5 mol / L sodium hydroxide solution was added at room temperature. The mixture was stirred at 85 °C at a stirring speed of 500 rpm / min for 24 h. After stirring, the mixture was cooled to room temperature, centrifuged, and dried at 100 °C for 12 h to obtain the precipitate. (5) Transfer the precipitate to a polypropylene container and repeat step (4) three times to finally obtain mesoporous scandium oxide material.

[0053] An application of a mesoporous scandium oxide material involves the electrocatalytic oxidation of 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid using the mesoporous scandium oxide material in step (5). The specific steps include: 4 mg of ground mesoporous scandium oxide material was added to a mixture of 900 μL ethanol and 100 μL Nafion solution, and sonicated to obtain a homogeneous solution. The homogeneous solution was dropped onto 1×2 cm nickel foam and dried at room temperature to obtain scandium oxide / nickel foam. An H-type electrolytic cell was assembled, using scandium oxide / nickel foam as the working electrode, Hg / HgO as the reference electrode, and platinum wire as the counter electrode. A pretreated Nafion-117 ion exchange membrane was used to separate the cathode chamber and the anode chamber. The electrolyte in the cathode chamber was 10 mL of 1 mol / L potassium hydroxide solution, and the electrolyte in the anode chamber was a mixture of 10 mL of 1 mol / L potassium hydroxide solution and 10 mmol / L 5-hydroxymethylfurfural solution. After assembly, a voltage is applied to the H-type electrolytic cell to complete the electrocatalytic oxidation of 5-hydroxymethylfurfural.

[0054] Performance testing: Using the Gamry electrochemical workstation, a three-electrode system was employed to conduct cyclic HMF electrolysis tests at 1.46 V for 6 cycles, with the working electrode remaining unchanged as the same scandium oxide / nickel foam. During each electrolysis test, when the charge reached 58C, a diluted sample was taken for high-performance liquid chromatography (HPLC) analysis. The corresponding FDCA yield, faradaic efficiency, and carbon balance were calculated using a standard curve.

[0055] The mesoporous scandium oxide material obtained in step (5) was subjected to nitrogen adsorption-desorption tests. The results showed that the mesoporous scandium oxide material has a high specific surface area (125 m²). 2 The scandium oxide ( / g) exhibits a pore size distribution concentrated around 4.7 nm and conforms to type IV adsorption curves, confirming that the prepared scandium oxide is a mesoporous material. Furthermore, as... Figure 5 SEM images showed that the prepared mesoporous scandium oxide consisted of spherical nanoparticles with a porous structure; cyclic electrolysis tests were performed on the scandium oxide / nickel foam. Figure 6 It can be seen that after five cycles of electrolysis at 1.46 V, the yield of FDCA and the Faraday efficiency of the reaction remained at approximately 90%, and from... Figure 7 It can be seen that the microstructure of the mesoporous scandium oxide remains basically unchanged after the reaction, which indicates that the mesoporous scandium oxide catalyst not only has excellent catalytic effect, but also has good stability.

[0056] In summary, compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: (1) The present invention uses mesoporous silica as a template. The mesoporous scandium oxide material prepared by the template method has a large specific surface area and rich pore structure. In the catalytic process, it can provide a wider range of contact with reactants and improve catalytic activity, thus providing a novel and efficient electrocatalyst for the electrocatalytic oxidation of HMF.

[0057] (2) The mesoporous scandium oxide electrocatalyst provided by the present invention can be used as a highly efficient catalyst for electrocatalytic oxidation of HMF. Compared with the original OER, it requires a lower potential to achieve the same current density, and can achieve good HMF catalytic effect, achieving 95% FDCA yield and Faraday efficiency.

[0058] (3) The material preparation method provided by the present invention is relatively simple, the raw materials can be obtained cheaply and the preparation process is green and environmentally friendly. It has high application value and broad application prospects in the field of electrocatalytic oxidation of 5-hydroxymethylfurfural, and is also suitable for industrial application.

[0059] Finally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0060] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0061] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a mesoporous scandium oxide material, characterized in that, The preparation method includes the following steps: S1. Add triblock copolymer P123 to deionized water and mix thoroughly to obtain solution A; add concentrated hydrochloric acid to solution A and stir to dissolve at 30-40°C to obtain solution B; add n-butanol to solution B and continue stirring for 1 hour, then add tetraethyl orthosilicate and stir at 400-600 rpm / min for 24 hours to obtain solution C; transfer solution C to a polypropylene container and carry out a hydrothermal reaction in an oven to obtain a reaction mixture, wherein the mass ratio of triblock copolymer P123 to deionized water, concentrated hydrochloric acid, n-butanol, and tetraethyl orthosilicate is 1:(20-50):(1-10):(1-10):(1-10); filter and dry to obtain a solid product; calcine the solid product to obtain a mesoporous silica template; S2. Dissolve scandium nitrate hydrate in ethanol to obtain solution D; add the mesoporous silica template to solution D and stir evenly to obtain a metal nitrate@mesoporous silica mixed solution E, wherein the mass ratio of the mesoporous silica template to the scandium nitrate hydrate and the ethanol is 1:(1-5):(3-10); dry and grind the mixed solution E to obtain a metal nitrate@mesoporous silica composite. S3. Calcining the metal nitrate@mesoporous silica composite to obtain a metal oxide@mesoporous silica composite. S4. The metal oxide@mesoporous silica composite is transferred to a polypropylene container, sodium hydroxide solution is added at room temperature, the temperature is raised to 70-90°C and stirring is continued for 24 hours. After stirring is completed, the mixture is cooled to room temperature, centrifuged and dried to obtain the precipitate. S5. Transfer the precipitate to a polypropylene container and repeat step S4 three times to obtain mesoporous scandium oxide material. In step S3, the calcination conditions include: The heating rate of the calcination is 1-3℃ / min; the calcination temperature is 500-700℃; and the calcination time is 2 hours. The specific surface area of ​​the mesoporous scandium oxide material is 110–220 m². 2 / g, the average pore size of the mesoporous scandium oxide material is 3-10 nm, and the pore volume of the mesoporous scandium oxide material is 0.3-1.2 cm³. 3 / g.

2. The method for preparing mesoporous scandium oxide material according to claim 1, characterized in that, The step of transferring the solution C into a polypropylene container and carrying out a hydrothermal reaction in an oven to obtain the reaction mixture specifically includes: The solution C was transferred to a polypropylene container and sealed for storage; the polypropylene container was placed in an oven and subjected to hydrothermal reaction at a temperature of 40–120°C for 24 hours; after the reaction was completed, the polypropylene container was cooled to room temperature to obtain the reaction mixture.

3. The method for preparing mesoporous scandium oxide material according to claim 2, characterized in that, In step S1, the calcination conditions include: The calcination heating rate is 1–3 °C / min; the calcination temperature is 500–600 °C; and the calcination time is 6 h.

4. The method for preparing mesoporous scandium oxide material according to claim 3, characterized in that, In step S2, the drying conditions include: The drying temperature is 50°C; the drying time is 12 hours.

5. The method for preparing mesoporous scandium oxide material according to claim 1, characterized in that, In step S4, the concentration of the sodium hydroxide solution is 1-5 mol / L; the volume of sodium hydroxide solution added is 50 mL.

6. The method for preparing mesoporous scandium oxide material according to claim 5, characterized in that, In step S4, the stirring rate is 400-600 rpm / min.

7. The method for preparing mesoporous scandium oxide material according to claim 6, characterized in that, In step S4, the drying conditions include: The drying temperature is 60–100°C; the drying time is 12–24 hours.

8. An application of a mesoporous scandium oxide material, characterized in that, The steps of electrocatalytic oxidation of 5-hydroxymethylfurfural using the mesoporous scandium oxide material include: The ground mesoporous scandium oxide material was added to a mixed solution of ethanol and Nafion solution and ultrasonically treated to obtain a homogeneous solution. The homogeneous solution was then dropped onto nickel foam and dried at room temperature to obtain scandium oxide / nickel foam. An H-type electrolytic cell was assembled, using scandium oxide / nickel foam as the working electrode, Hg / HgO as the reference electrode, and platinum wire as the counter electrode. A pretreated Nafion-117 ion exchange membrane was used to separate the cathode chamber and the anode chamber. The electrolyte in the cathode chamber was a 1 mol / L potassium hydroxide solution, and the electrolyte in the anode chamber was a mixed solution of a 1 mol / L potassium hydroxide solution and a 10 mmol / L 5-hydroxymethylfurfural solution. After assembly, a voltage is applied to the H-type electrolytic cell to complete the electrocatalytic oxidation of 5-hydroxymethylfurfural; The mesoporous scandium oxide material is the mesoporous scandium oxide material prepared by the preparation method described in claim 1.

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