Synthesis method of CeO2 / Metal-SA
By mixing CeO2 and metal in water and separating solvents to prepare CeO2/Metal-SA, the problem of easy aggregation of single atoms on the support is solved, and the preparation of CeO2/Metal-SA materials with low cost, easy separation and large-scale production is achieved.
Patent Information
- Application Number
- CN202311753628.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-20
- Publication Date
- 2025-06-20
AI Technical Summary
In the existing SACs synthesis methods, single atoms are prone to aggregation on the support, the synthesis strategy is high and does not have the value of large-scale production, and it is difficult to separate the catalyst and the product.
CeO2 is used as a carrier, and the solvent is separated by mixing with metal in water and reacting, and dried to obtain CeO2/Metal-SA, and the reaction time is controlled to adjust the single-atom load.
It achieves uniform single-atom loading, reduces costs, simplifies the preparation process, has the potential of green environmental protection and large-scale production, and the catalyst and product are easily separated.
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Abstract
Description
Technical Field
[0001] This disclosure belongs to the field of material synthesis and relates to a preparation method of CeO2 / Metal-SA materials. Background Art
[0002] The statements herein merely provide background information related to this disclosure and do not necessarily constitute prior art.
[0003] Single-atom materials (SACs) are materials that anchor isolated metal atoms on solid supports. They have both the advantages of heterogeneous materials such as easy separation, good recyclability, and easy fixation, and the advantages of homogeneous materials such as highly uniform active centers, adjustable coordination environments, and high atomic utilization efficiency. Therefore, SACs have great application prospects in bridging the gap between heterogeneous and homogeneous catalysis. In addition, SACs provide a fundamental platform to probe the catalytic structure-performance relationship and study the catalytic mechanism at the atomic scale.
[0004] The use of SACs usually significantly improves catalytic activity, selectivity, and stability, and even endows different catalytic properties from the corresponding nanoparticles and nanoclusters. SACs have attracted extensive scientific attention because they can be used as alternatives to avoid the high cost problem of noble metal materials used in large-scale catalytic applications. Specifically, the active single-atom sites are well stabilized on the support, and the same geometric structure of each active site is similar to that of homogeneous materials.
[0005] Due to the high surface energy of single atoms in SACs, it is still a challenge to disperse single metal atoms on a suitable support and prevent them from agglomerating. Single atoms can be stabilized on the support through chemical bonds. Therefore, the interaction between the metal and the support plays an important role in the synthesis of SACs. In this case, anchoring sites such as defects, ligands, and porous structures are crucial for stabilizing single-atom metals. In recent years, various synthetic strategies for preparing metal SACs have been reported, such as wet impregnation techniques, atomic layer deposition strategies, coprecipitation methods, low-temperature chemical reduction methods, high-temperature pyrolysis methods, etc. The advantages and disadvantages of the above methods are listed in Table 1. This disclosure proposes a novel method to prepare a series of CeO2 / Metal-SA.
[0006] Table 1 Synthesis strategy Advantages Disadvantages Wet impregnation technique Simple operation and high noble metal utilization rate Atoms are prone to aggregation on the carrier Atomic layer deposition strategy Controllable and uniform distribution of active atoms High cost Coprecipitation method Uniform distribution of active atoms, mature technology and wide application Low loading amount Low-temperature chemical reduction method Maintain the original structural form Weak coupling effect High-temperature pyrolysis method High loading amount and good dispersion The structural change is unpredictable Summary of the Invention
[0007] To address the deficiencies of existing SACs synthesis methods, the objective of this disclosure is to provide a preparation method capable of synthesizing a series of SACs.
[0008] To achieve the above objective, the technical solution of this disclosure is as follows:
[0009] First, disperse the carrier CeO2 in water, and then, under conditions such as stirring, ultrasonic treatment, or oscillation, fully mix and contact the CeO2 solution with the metal. After reacting for a period of time, separate the metal from the solution. After removing the solvent from the separated solution and drying it, CeO2 / Metal-SA can be obtained.
[0010] The preparation method provided by the present disclosure is simple, low-cost, environmentally friendly, can control the single-atom loading amount through the reaction time, and has universality and value for large-scale production.
[0011] The beneficial effects of the present disclosure are as follows:
[0012] 1. CeO2 / Metal-SA can solve the problem that it is difficult to separate the catalyst from the raw materials and products in homogeneous catalysis, has good recyclability, and reduces the experimental cost.
[0013] 2. The preparation method provided by the present disclosure is simple, relatively low-cost, can control the single-atom loading amount, and has universality and value for large-scale production.
[0014] 3. The preparation method of the present disclosure conforms to the concept of green chemistry, has strong practicability, and is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The schematic diagrams in the specification forming a part of the present disclosure are used to provide a further understanding of the present disclosure. The illustrative embodiments and descriptions thereof of the present disclosure are used to explain the present disclosure and do not constitute an improper limitation to the present disclosure.
[0016] Figure 1 XRD, HRTEM, HAADF-STEM, K-edge XANES, and EXAFS characterization diagrams of CeO2 / Fe-SA prepared in Example 1 of the present disclosure. Through the characterization, it is proved that Fe is loaded in the form of single atoms.
[0017] Figure 2 XRD, HRTEM, HAADF-STEM, K-edge XANES, and EXAFS characterization diagrams of CeO2 / Zn-SA prepared in Example 2 of the present disclosure. Through the characterization, it is proved that Zn is loaded in the form of single atoms.
[0018] Figure 3 XRD, HRTEM, HAADF-STEM, K-edge XANES, and EXAFS characterization diagrams of CeO2 / Sn-SA prepared in Example 3 of the present disclosure. Through the characterization, it is proved that Sn is loaded in the form of single atoms.
[0019] Figure 4XRD, HRTEM, and HAADF-STEM characterization diagrams of CeO2 / Mg-SA prepared in Example 4 of the present disclosure, which prove that Mg is loaded in the form of single atoms through characterization. Embodiment
[0020] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present disclosure belongs.
[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0022] A typical embodiment of the present disclosure provides a preparation method capable of synthesizing a series of CeO2 / Metal-SA materials. The process is as follows: First, disperse CeO2 in water, and then under conditions such as stirring, ultrasonic treatment, or oscillation, fully mix and contact the CeO2 solution with the metal. After reacting for a period of time, separate the metal from the solution. After removing the solvent and drying the separated solution, CeO2 / Metal-SA can be obtained.
[0023] In a typical embodiment, the metal is not limited to the examples listed, as long as it can be oxidized by Ce in CeO2 4+ Any metal that can be oxidized can be applicable to this method.
[0024] In a typical embodiment, there are no specific limitations on the form and size of the metal source.
[0025] In a typical embodiment, the reaction conditions with the metal source include but are not limited to ultrasonic treatment, stirring, and oscillation.
[0026] Furthermore, the loading amount of the metal component on the CeO2 support can be adjusted by adjusting the amount of the metal source added and the reaction time.
[0027] The principle of the present disclosure is as follows:
[0028] Ce in CeO2 4+ Undergoes a redox reaction with the metal source, and finally the metal is anchored on CeO2 in the form of single atoms.
[0029] To enable those skilled in the art to more clearly understand the technical solutions of the present disclosure, the technical solutions of the present disclosure will be described in detail below in conjunction with specific examples and comparative examples.
[0030] Example 1:
[0031] (1) Weigh 50 mg of CeO2 nanorods in a beaker, add 100 mL of deionized water, and perform ultrasonic dispersion.
[0032] (2) Add reduced iron powder to the above-mentioned uniformly dispersed solution and perform ultrasonic treatment.
[0033] (3) After reacting for a certain period of time, separate the iron powder from the solution and remove the solvent to obtain CeO2 / Fe-SA.
[0034] Example 2:
[0035] (1) Weigh 50 mg of CeO2 nanorods in a beaker, add 100 mL of deionized water, and perform ultrasonic dispersion.
[0036] (2) Add a zinc sheet to the above-mentioned uniformly dispersed solution and stir.
[0037] (3) After reacting for a certain period of time, take out the zinc sheet from the solution and remove the solvent to obtain CeO2 / Zn-SA.
[0038] Example 3:
[0039] (1) Weigh 50 mg of CeO2 nanorods in a beaker, add 100 mL of deionized water, and perform ultrasonic dispersion.
[0040] (2) Add a tin sheet to the above-mentioned uniformly dispersed solution and stir.
[0041] (3) After reacting for a certain period of time, take out the tin sheet from the solution and remove the solvent to obtain CeO2 / Sn-SA.
[0042] Example 4:
[0043] (1) Weigh 50 mg of CeO2 nanorods in a beaker, add 100 mL of deionized water, and perform ultrasonic dispersion.
[0044] (2) Add a magnesium strip with magnesium oxide removed to the above-mentioned uniformly dispersed solution and oscillate.
[0045] (3) After reacting for a certain period of time, take out the magnesium strip from the solution and remove the solvent to obtain CeO2 / Mg-SA.
[0046] The foregoing are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure. Although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.
Claims
1. A series of metal single-atom materials, which can be expressed as CeO2 / Metal-SA (Metal represents metal, and SA represents single atom).
2. A preparation method for a series of CeO2 / Metal-SA, characterized in that, The carrier is CeO2, and its size is nanoscale or micron-scale.
3. A preparation method for a series of CeO2 / Metal-SA, characterized in that, Disperse CeO2 in water to prepare a mixed solution.
4. The preparation method for a series of CeO2 / Metal-SA according to claim 3, characterized in that, React the CeO2 mixed solution with different metal sources. After the reaction, separate the solution from the metal source to obtain CeO2 / Metal-SA.
5. The preparation method for a series of CeO2 / Metal-SA according to claim 3, characterized in that, There are no clear requirements for the morphology and size of the metal source. Any metal that can react with CeO2 belongs to the requirements of the present invention.
6. The preparation method for a series of CeO2 / Metal-SA according to claim 3, characterized in that, The reaction methods of CeO2 with different metal sources include but are not limited to stirring, ultrasonic treatment, and oscillation.
7. The preparation method for a series of CeO2 / Metal-SA according to claim 3, characterized in that, The separation method of the single-atom catalyst after the reaction is not limited, and any method that can separate the product can be applied.
8. The preparation method for a series of CeO2 / Metal-SA according to claim 3, characterized in that, Removing the separated solvent can obtain CeO2 / Metal-SA.