Tungstate nanomaterial, preparation method thereof and electro-synthesis of hydrogen peroxide application
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HAINAN UNIV
- Filing Date
- 2026-03-19
- Publication Date
- 2026-05-29
AI Technical Summary
Existing catalysts for the electrochemical oxygen reduction synthesis of hydrogen peroxide suffer from the scarcity of precious metal resources, high costs, and carbon corrosion problems, which limit their application in the field of electrochemical oxygen reduction synthesis of hydrogen peroxide. Furthermore, transition metal tungstates have not been widely reported in this field.
Tungstate nanomaterials were prepared by solvothermal reaction using tungsten source, transition metal salt and surfactant. These nanomaterials were then used as catalysts for the electrochemical oxygen reduction synthesis of hydrogen peroxide, avoiding carbon corrosion problems and exhibiting high selectivity and stability.
The prepared tungstate nanomaterials exhibit high H2O2 selectivity in alkaline media and do not decay in selectivity after 20,000 cyclic voltammetry tests, demonstrating excellent electrochemical stability and low cost advantages, making them suitable for large-scale industrial production.
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Figure CN122102210A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrochemical oxygen reduction synthesis of hydrogen peroxide, and particularly to a tungstate nanomaterial, its preparation method, and its application in the electrosynthesis of hydrogen peroxide. Background Technology
[0002] Hydrogen peroxide (H2O2) can produce water through reduction and release oxygen through oxidation, making it an important green redox agent with wide applications in papermaking, textiles, printing and dyeing, water treatment, semiconductors, and aerospace. In recent years, the electrochemical synthesis of H2O2 has seen rapid development. Among these methods, electrochemical oxygen reduction synthesis of H2O2, using water, oxygen, or air as raw materials, achieves a green, controllable, and portable synthesis of H2O2, solving the problems of high energy consumption, environmental pollution, and safety hazards associated with the traditional anthraquinone method, making it a current research hotspot.
[0003] The key to the electrochemical oxygen reduction synthesis of H2O2 lies in developing catalysts with high H2O2 selectivity and stability. Currently, catalysts for electrochemical oxygen reduction synthesis of H2O2 fall into several categories, including noble metal alloys, carbon-based single-atom materials, non-metallic carbon-based materials, and transition metal oxides, sulfides, and selenides. While noble metal alloys exhibit high H2O2 selectivity, the scarcity and high cost of precious metals limit their large-scale application. Carbon-based single-atom materials and non-metallic carbon-based materials face the challenge of carbon corrosion during long-term use, resulting in limited service life. Therefore, developing low-cost catalysts with high H2O2 selectivity and stability is of great significance.
[0004] Transition metal compounds are characterized by their diversity, rich structure, and wide range of sources. Among them, transition metal tungstates have relatively stable structures, and the composition of their bimetallic components makes their composition tunable and their electronic structure rich, which makes them promising for catalytic oxygen reduction synthesis of H2O2.
[0005] Chinese patent CN112264004A discloses a tungstate-based catalytic material and its application in water oxidation to H2O2. It uses sodium tungstate, metal salts, and other raw materials to prepare a series of tungstate catalysts via hydrothermal synthesis. The main components of the prepared catalytic material include one or more of Bi2WO6, CaWO4, SnWO4, ZnWO4, CoWO4, and MnWO4. However, the application field of the above patent is water oxidation to H2O2 synthesis, and it does not involve oxygen reduction to H2O2 synthesis. It should be noted that water oxidation to H2O2 synthesis and electrochemical oxygen reduction to H2O2 synthesis are two completely different technologies. The former synthesizes H2O2 through the oxidation reaction of water, while the latter synthesizes H2O2 through the reduction reaction of oxygen. The two have significant differences in principle and technology.
[0006] Chinese patent CN118002140A discloses a transition metal tungstate catalyst and a method for synthesizing valeramide using the same. The method involves uniformly mixing a transition metal tungstate, a pretreated support, and a solvent, then allowing the mixture to stand at room temperature for impregnation, followed by drying and pulverization to obtain the transition metal tungstate, which contains one or more of FeWO4, CoWO4, NiWO4, and CuWO4. However, its application is limited to the synthesis of valeramide and does not involve the electrochemical oxygen reduction synthesis of H2O2.
[0007] In summary, although transition metal tungstates have been reported, their application in the electrochemical oxygen reduction synthesis of H2O2 has not yet been reported. Summary of the Invention
[0008] In view of this, the present invention provides a tungstate nanomaterial, a method for its preparation, and an application in the electrosynthesis of hydrogen peroxide. The tungstate nanomaterial provided by the present invention can efficiently catalyze the electrosynthesis of H2O2.
[0009] This invention provides a method for preparing tungstate nanomaterials, comprising the following steps: The tungsten source, transition metal salt, surfactant and solvent are mixed (denoted as the first mixture) and subjected to a solvothermal reaction to obtain the tungstate nanomaterial.
[0010] Preferably, the tungsten source includes one or more of tungsten salts and tungstates; the tungsten salt includes one or more of tungstates, metatungstates, and paratungstates; the tungstate includes one or more of ammonium tungstate, sodium tungstate, potassium tungstate, and lithium tungstate; the metatungstate includes one or more of ammonium metatungstate, sodium metatungstate, potassium metatungstate, and lithium metatungstate; and the paratungstate includes one or more of ammonium paratungstate, sodium paratungstate, potassium paratungstate, and lithium paratungstate.
[0011] Preferably, the transition metal salt includes one or more of transition metal nitrates, transition metal chlorides, transition metal sulfates, transition metal formates, and transition metal acetates; the transition metal nitrate includes one or more of zinc nitrate, nickel nitrate, and copper nitrate; the transition metal chloride includes one or more of zinc chloride, nickel chloride, and copper chloride; the transition metal sulfate includes one or more of zinc sulfate, nickel sulfate, and copper sulfate; the transition metal formate includes one or more of zinc formate, nickel formate, and copper formate; and the transition metal acetate includes one or more of zinc acetate, nickel acetate, and copper acetate.
[0012] Preferably, the surfactant comprises one or more of sodium dodecyl sulfonate, polyvinylpyrrolidone, and hexadecyltrimethylammonium salt; the hexadecyltrimethylammonium salt comprises one or more of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium iodide, and hexadecyltrimethylammonium fluoride.
[0013] Preferably, the molar ratio of the tungsten source to the transition metal salt is 0.1~20:0.1~20; and the molar ratio of the surfactant to the transition metal salt is 0.1~20:0.1~20.
[0014] Preferably, the solvothermal reaction is carried out in a reaction vessel; the temperature of the solvothermal reaction is 110~190℃, and the holding time is 3~24 hours.
[0015] The present invention also provides a tungstate nanomaterial, which is obtained by the preparation method of the tungstate nanomaterial described above.
[0016] Preferably, the tungstate nanomaterial is rod-shaped or granular, with a size of 5-200 nanometers.
[0017] Preferably, the tungstate nanomaterial includes one or more of ZnWO4 tungstate nanomaterials, NiWO4 tungstate nanomaterials, and CuWO4 tungstate nanomaterials.
[0018] The present invention also provides an application of tungstate nanomaterials in the electrosynthesis of H2O2, wherein the tungstate nanomaterials are those described in the above-mentioned scheme.
[0019] This invention provides a method for preparing tungstate nanomaterials. The preparation method provided by this invention is simple in steps, convenient to operate, safe, low in energy consumption, cost-controllable, widely applicable, and has low dependence on equipment, making it suitable for large-scale industrial production.
[0020] This invention also provides a tungstate nanomaterial, obtained using the preparation method described above. The tungstate nanomaterial provided by this invention can be used directly as a catalyst. Its active component is a transition metal tungstate nanomaterial, which has a stable structure, no carbon active centers, avoids carbon corrosion problems, and exhibits excellent electrochemical stability. The tungstate nanomaterial provided by this invention shows an H2O2 selectivity of over 83% in alkaline media, and its H2O2 selectivity does not decrease after 20,000 cyclic voltammetry cycles, making it one of the best-performing catalysts for the electrochemical oxygen reduction synthesis of H2O2 in alkaline media.
[0021] This invention also provides an application of tungstate nanomaterials in the electrosynthesis of H2O2, wherein the tungstate nanomaterials are those described in the above-mentioned scheme. The tungstate nanomaterials provided by this invention can be used as catalysts for the electrochemical oxygen reduction synthesis of H2O2. The electrochemical oxygen reduction synthesis of H2O2 in an alkaline medium exhibits advantages such as excellent stability, high H2O2 selectivity, and low cost, which is of great significance for promoting the development and application of electrochemical oxygen reduction synthesis of H2O2. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of this invention, the accompanying drawings used in the embodiments of this invention or in the prior art are briefly described below. For those skilled in the art, other drawings can be derived from the following drawings without creative effort, and all such drawings are within the protection scope of this invention.
[0023] Figure 1 The image shows the X-ray diffraction (XRD) pattern of the ZnWO4 tungstate nanomaterial in Example 1. Figure 2 This is a transmission electron microscope (TEM) image of the ZnWO4 tungstate nanomaterials from Example 1. Figure 3 This is a high-resolution TEM image of the ZnWO4 tungstate nanomaterial from Example 1; Figure 4 This is a polarization curve of the ZnWO4 tungstate nanomaterial in alkaline medium from Example 1. Figure 5 The H2O2 selectivity diagram of the ZnWO4 tungstate nanomaterials in Example 1 is shown. Figure 6 This is a cyclic voltammetric scan of the H2O2 selectivity of the ZnWO4 tungstate nanomaterial in Example 1 in an alkaline medium. Figure 7 The image shows the XRD pattern of the NiWO4 tungstate nanomaterial from Example 2. Figure 8 This is a TEM image of the NiWO4 tungstate nanomaterial from Example 2; Figure 9 This is a high-resolution TEM image of the NiWO4 tungstate nanomaterial from Example 2; Figure 10 This is a diagram showing the H2O2 selectivity of the NiWO4 tungstate nanomaterials in Example 2. Detailed Implementation
[0024] This invention provides a method for preparing tungstate nanomaterials, comprising the following steps: The tungstate nanomaterial is obtained by mixing a tungsten source, a transition metal salt, a surfactant, and a solvent and carrying out a solvothermal reaction.
[0025] In this invention, the tungsten source preferably includes one or more of tungsten salts and tungstates; the tungsten salt preferably includes one or more of tungstates, metatungstates, and paratungstates; the tungstate preferably includes one or more of ammonium tungstate, sodium tungstate, potassium tungstate, and lithium tungstate; the metatungstate preferably includes one or more of ammonium metatungstate, sodium metatungstate, potassium metatungstate, and lithium metatungstate; and the paratungstate preferably includes one or more of ammonium paratungstate, sodium paratungstate, potassium paratungstate, and lithium paratungstate.
[0026] In this invention, the transition metal salt preferably includes one or more of transition metal nitrates, transition metal chlorides, transition metal sulfates, transition metal formates, and transition metal acetates; the transition metal nitrate preferably includes one or more of zinc nitrate, nickel nitrate, and copper nitrate; the transition metal chloride preferably includes one or more of zinc chloride, nickel chloride, and copper chloride; the transition metal sulfate preferably includes one or more of zinc sulfate, nickel sulfate, and copper sulfate; the transition metal formate preferably includes one or more of zinc formate, nickel formate, and copper formate; and the transition metal acetate preferably includes one or more of zinc acetate, nickel acetate, and copper acetate.
[0027] In this invention, the molar ratio of the tungsten source to the transition metal salt is preferably 0.1~20:0.1~20, more preferably 1~18:1~18, even more preferably 3~15:3~15, and even more preferably 7~10:7~10.
[0028] In this invention, the surfactant preferably includes one or more of sodium dodecyl sulfonate, polyvinylpyrrolidone, and hexadecyltrimethylammonium salt; the hexadecyltrimethylammonium salt preferably includes one or more of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium iodide, and hexadecyltrimethylammonium fluoride.
[0029] In this invention, the molar ratio of the surfactant to the transition metal salt is preferably 0.1~20:0.1~20, more preferably 1~15:1~15, even more preferably 5~12:5~12, and even more preferably 8~10:8~10.
[0030] In this invention, the solvent preferably includes one or more of water and organic solvents; the organic solvent is preferably an alcohol solvent; and the alcohol solvent preferably includes one or more of methanol and ethanol.
[0031] In this invention, the preferred mass ratio of the tungsten source to the solvent is (0.1~20) mol: (10~200) L, more preferably (1~15) mol: (30~160) L, and even more preferably (5~10) mol: (70~120) L.
[0032] In this invention, the first mixing preferably includes the following steps: mixing a tungsten source and a portion of a solvent to obtain a tungsten source solution, mixing a transition metal salt and the remaining solvent to obtain a transition metal salt solution, and mixing the tungsten source solution with the transition metal salt solution and a surfactant (referred to as the second mixing).
[0033] In this invention, the volume ratio of the partial solvent to the remaining solvent is preferably 2:1 to 2, and more preferably 4:3.
[0034] In this invention, the second mixing method is preferably ultrasonication followed by stirring; the ultrasonication time is preferably 10-40 minutes, more preferably 20-30 minutes; the stirring time is preferably 30-120 minutes, more preferably 50-100 minutes, and even more preferably 90 minutes.
[0035] In this invention, the solvothermal reaction is preferably carried out in a reaction vessel; the temperature of the solvothermal reaction is preferably 110~190℃, more preferably 130~160℃, and the holding time is preferably 3~24 hours, more preferably 8~16 hours, and even more preferably 12 hours.
[0036] In this invention, the solvothermal reaction preferably further includes sequentially cooling, solid-liquid separation, washing, and drying the resulting product.
[0037] In this invention, the cooling is preferably natural cooling; the final cooling temperature is preferably room temperature (20~40℃).
[0038] In this invention, the solid-liquid separation is preferably performed by vacuum filtration.
[0039] In this invention, the washing is preferably done with water; the water used for washing is preferably deionized water; and the number of times the water is washed is preferably 5 or more.
[0040] In this invention, the drying temperature is preferably 58~62℃, more preferably 60℃, and the heat preservation time is preferably 11~13 hours, more preferably 12 hours.
[0041] The present invention also provides a tungstate nanomaterial, which is obtained by the preparation method of the tungstate nanomaterial described above.
[0042] In this invention, the tungstate nanomaterial is preferably rod-shaped or granular, and its size (referring to the width of the rod or the diameter of the granule) is preferably 5-200 nanometers, more preferably 10-150 nanometers.
[0043] In this invention, the tungstate nanomaterial preferably includes one or more of zinc tungstate (ZnWO4) tungstate nanomaterials, nickel tungstate (NiWO4) tungstate nanomaterials, and copper tungstate (CuWO4) tungstate nanomaterials.
[0044] The present invention also provides an application of tungstate nanomaterials in the electrosynthesis of H2O2, wherein the tungstate nanomaterials are those described in the above-mentioned scheme.
[0045] The tungstate nanomaterials provided by this invention can be used as catalysts for the electrochemical oxygen reduction synthesis of H2O2. The electrochemical oxygen reduction synthesis of H2O2 in alkaline media has advantages such as excellent stability, high H2O2 selectivity and low cost, which is of great significance for promoting the development and application of electrochemical oxygen reduction synthesis of H2O2.
[0046] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments.
[0047] Example 1: This embodiment prepared and characterized ZnWO4 tungstate nanomaterials, as detailed below: (1) Preparation of ZnWO4 tungstate nanomaterials: 2 mmol of Na₂WO₄ and 3 mmol of Zn(NO₃)₂ were dissolved in 40 mL and 20 mL of deionized water, respectively. After dissolution, the two solutions were mixed and 4 mmol of cetyltrimethylammonium bromide was added. The mixture was then sonicated (30 min) and stirred (30 min) for 1 hour. The mixture was then transferred to a 100 mL reactor and subjected to a solvothermal reaction at 180 °C for 12 hours. After the solvothermal reaction was completed, the mixture was allowed to cool naturally to room temperature. The resulting product was separated by filtration and washed five times with deionized water. It was then dried in a 60 °C oven for 12 hours to obtain ZnWO₄ tungstate nanomaterials.
[0048] (2) Structural characterization: The phase structure of the ZnWO4 tungstate nanomaterials prepared in this embodiment was characterized by XRD, and the results are as follows: Figure 1 As shown. According to Figure 1 It can be seen that the diffraction peaks of the ZnWO4 tungstate nanomaterial prepared in this embodiment are consistent with those of standard ZnWO4.
[0049] The ZnWO4 tungstate nanomaterials prepared in this embodiment were characterized using TEM, and the results are as follows: Figure 2 As shown. According to Figure 2 As can be seen, the ZnWO4 tungstate nanomaterials prepared in this embodiment have a nanorod morphology.
[0050] The ZnWO4 tungstate nanomaterials prepared in this embodiment were characterized using high-resolution TEM, and the results are as follows: Figure 3 As shown. According to Figure 3 It can be clearly seen that the lattice fringes of the nanorods correspond to ZnWO4, further confirming that its phase structure is ZnWO4.
[0051] (3) Performance testing: The polarization curves of ZnWO4 tungstate nanomaterials were measured using a rotating ring-disk electrode in an oxygen-saturated 0.1M KOH solution at a scan rate of 10 mV / s and an electrode rotation speed of 1600 rpm via linear voltammetry. The results are as follows: Figure 4 As shown; the selectivity for synthesizing H2O2 was calculated, and the results are as follows. Figure 5 As shown; and after 20,000 cyclic voltammetric scans at 0.1~0.7V, the stability of its synthesized H2O2 was tested, and the results are as follows. Figure 6 As shown.
[0052] according to Figures 4-6 It can be seen that the ZnWO4 tungstate nanomaterials prepared in this embodiment exhibit excellent H2O2 selectivity and stability in alkaline media. Its H2O2 selectivity is 90.9-97.6% at 0.1-0.6V vs. RHE, and after 20,000 cycles, its H2O2 selectivity is still 92.7-93.5%, which is very high.
[0053] Example 2: This embodiment prepared and characterized NiWO4 tungstate nanomaterials, as detailed below: (1) Preparation of NiWO4 tungstate nanomaterials: 3 mmol of Na₂WO₄ and 3 mmol of Ni(NO₃)₂ were dissolved in 30 mL and 30 mL of deionized water, respectively. After dissolution, the two solutions were mixed and 3 mmol of sodium dodecyl sulfonate was added. The mixture was then sonicated (10 min) and stirred (50 min) for 1 hour. The mixture was then transferred to a 100 mL reactor and subjected to a solvothermal reaction in a 160 °C oven for 16 hours. After the solvothermal reaction was completed, the mixture was allowed to cool naturally to room temperature. The resulting product was separated by filtration and washed five times with deionized water. It was then dried in a 60 °C oven for 12 hours to obtain NiWO₄ tungstate nanomaterials.
[0054] (2) Structural characterization: The phase structure of the NiWO4 tungstate nanomaterials prepared in this embodiment was characterized by XRD, and the results are as follows: Figure 7 As shown. According to Figure 7 It can be seen that the diffraction peaks of the NiWO4 tungstate nanomaterial prepared in this embodiment are consistent with those of standard NiWO4.
[0055] The NiWO4 tungstate nanomaterials prepared in this embodiment were characterized using TEM, and the results are as follows: Figure 8 As shown. According to Figure 8 As can be seen, the NiWO4 tungstate nanomaterials prepared in this embodiment have a nanoparticle morphology.
[0056] The NiWO4 tungstate nanomaterials prepared in this embodiment were characterized using high-resolution TEM, and the results are as follows: Figure 9 As shown. According to Figure 9 It can be clearly seen that the lattice fringes of the NiWO4 tungstate nanoparticles correspond to those of NiWO4, further confirming that its phase structure is NiWO4.
[0057] (3) Performance testing: Using the same test method as in Example 1, the results are as follows: Figure 10 As shown. According to Figure 10 It can be seen that the NiWO4 tungstate nanomaterials prepared in this embodiment exhibit high H2O2 selectivity in alkaline media, with an H2O2 selectivity of 83.3% at 0.1V vs. RHE.
[0058] Example 3: The preparation method in this embodiment is the same as that in Example 1, except that Zn(NO3)2 is replaced with copper nitrate.
[0059] The results of structural characterization and performance testing in Example 3 are similar to those in Example 1, and will not be repeated here.
[0060] Based on the above embodiments and test data, it can be seen that the tungstate nanomaterials provided by this invention are used for the electrochemical oxygen reduction synthesis of H2O2 in alkaline media. The H2O2 selectivity is above 83%, and the H2O2 selectivity does not decrease after 20,000 cycles of cyclic voltammetry testing. It is one of the best performing catalysts for the electrochemical oxygen reduction synthesis of H2O2 in alkaline media, with significant economic and social benefits and broad application prospects.
[0061] The embodiments of the present invention have been described above; however, these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. All other embodiments obtained by those skilled in the art based on the above embodiments of the present invention without inventive effort are within the protection scope of the present invention.
Claims
1. A method for preparing tungstate nanomaterials, characterized in that, Includes the following steps: The tungstate nanomaterial is obtained by mixing a tungsten source, a transition metal salt, a surfactant, and a solvent and carrying out a solvothermal reaction.
2. The preparation method according to claim 1, characterized in that, The tungsten source includes one or more of tungsten salts and tungstic acid; The tungsten salt includes one or more of tungstate, metatungstate and paratungstate; The tungstate includes one or more of ammonium tungstate, sodium tungstate, potassium tungstate, and lithium tungstate; The metatungstate includes one or more of ammonium metatungstate, sodium metatungstate, potassium metatungstate, and lithium metatungstate; The paratungstate includes one or more of ammonium paratungstate, sodium paratungstate, potassium paratungstate, and lithium paratungstate.
3. The preparation method according to claim 1, characterized in that, The transition metal salts include one or more of transition metal nitrates, transition metal chlorides, transition metal sulfates, transition metal formates, and transition metal acetates; The transition metal nitrates include one or more of zinc nitrate, nickel nitrate, and copper nitrate; The transition metal chlorides include one or more of zinc chloride, nickel chloride, and copper chloride; The transition metal sulfates include one or more of zinc sulfate, nickel sulfate, and copper sulfate; The transition metal formate includes one or more of zinc formate, nickel formate, and copper formate; The transition metal acetates include one or more of zinc acetate, nickel acetate, and copper acetate.
4. The preparation method according to claim 1, characterized in that, The surfactant includes one or more of sodium dodecyl sulfonate, polyvinylpyrrolidone, and hexadecyltrimethylammonium salt; The hexadecyltrimethylammonium salt includes one or more of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium iodide, and hexadecyltrimethylammonium fluoride.
5. The preparation method according to claim 1, characterized in that, The molar ratio of the tungsten source to the transition metal salt is 0.1~20:0.1~20; The molar ratio of the surfactant to the transition metal salt is 0.1~20:0.1~20.
6. The preparation method according to claim 1, characterized in that, The solvothermal reaction is carried out in a reaction vessel; The temperature of the solvothermal reaction is 110~190℃, and the holding time is 3~24 hours.
7. A tungstate nanomaterial, characterized in that, The tungstate nanomaterials were prepared using any one of claims 1 to 6.
8. The tungstate nanomaterial according to claim 7, characterized in that, The tungstate nanomaterials are rod-shaped or granular, with a size of 5-200 nanometers.
9. The tungstate nanomaterial according to claim 7, characterized in that, The tungstate nanomaterials include one or more of ZnWO4 tungstate nanomaterials, NiWO4 tungstate nanomaterials, and CuWO4 tungstate nanomaterials.
10. The application of a tungstate nanomaterial in the electrosynthesis of H2O2, characterized in that, The tungstate nanomaterial is the tungstate nanomaterial according to any one of claims 7 to 9.