A carbon nanosheet supported Cu monatomic Pt sub-nanocluster catalyst, a preparation method and application thereof
By anchoring Cu single atoms and Pt sub-nano clusters on carbon nanosheets, the problem of insufficient H* proton supply in alkaline water electrolysis of platinum-based catalysts was solved, realizing the preparation of highly efficient electrochemical catalysts suitable for alkaline HER reactions.
Patent Information
- Application Number
- CN202411501562.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2044-10-25
AI Technical Summary
Existing platinum-based catalysts suffer from insufficient H* proton supply in alkaline water electrolysis, leading to kinetic barriers in the HER reaction. Furthermore, atomically dispersed platinum catalysts are prone to aggregation or dissolution during long-term use, resulting in limited activity.
Using carbon nanosheets as a support, Cu single atoms and Pt sub-nano clusters are independently dispersed and anchored. Cu single-atom Pt sub-nano cluster catalysts are prepared by in-situ adsorption and high-temperature pyrolysis, forming a large number of defect sites, which improves the active metal loading and the electrochemical performance of the catalyst under alkaline conditions.
The HER reaction was achieved under alkaline conditions. The catalyst exhibited excellent electrochemical performance in alkaline water electrolysis for hydrogen production, and the preparation method was simple and low in cost.
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Figure CN119593000B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of catalysts, and relates to a carbon nanosheet supported Cu monatomic Pt sub-nanocluster catalyst as well as a preparation method and application thereof. BACKGROUND
[0002] The hydrogen evolution reaction (HER) is one of the half-reactions in the water electrolysis process, which involves the decomposition of water molecules into hydrogen and oxygen, and is crucial for realizing efficient hydrogen energy economy. Solving the inherent kinetic barrier in the hydrogen evolution reaction has been an important obstacle in promoting sustainable energy conversion technology, and electrochemical water splitting powered by renewable energy provides a green and sustainable way for efficient hydrogen production.
[0003] Compared with water electrolysis in acidic medium, alkaline water electrolysis technology is more popular and feasible in actual industrial hydrogen production due to its advantages of solid equipment and cheap electrolytic cell structure. So far, platinum-based catalysts are widely used as alkaline HER electrocatalysts due to their suitable hydrogen adsorption energy. However, the weak water dissociation ability of Pt leads to insufficient H* proton supply in the Volmer step, especially in the operation at industrial current density in anion exchange membrane water electrolysis. In this context, designing and developing high energy density, low price and sustainable green electrochemical catalysts has become a research hotspot at present.
[0004] In order to solve the above problems and further promote the development of sustainable energy, researchers are committed to designing and developing electrochemical catalysts with high performance and environmental friendliness. Atomically dispersed platinum catalysts are indeed an ideal high-atom utilization catalyst, but still need to be improved. On the one hand, atomically dispersed platinum catalysts tend to aggregate into clusters or dissolve in long-term tests. In addition, due to strong metal support interaction and non-free adjustment, the activity is still easily limited by the charge transfer from the metal to the surrounding carrier atoms. In order to overcome these difficulties, it is crucial to design a catalyst with flexible valence and easily adjustable electronic structure of the supported metal. SUMMARY
[0005] The present application aims at the deficiencies in the prior art, and provides a carbon nanosheet supported Cu monatomic Pt sub-nanocluster catalyst as well as a preparation method and application thereof. The prepared catalyst can be applied to hydrogen production as a hydrogen evolution catalyst, and has excellent electrochemical performance under alkaline conditions.
[0006] One object of the present application is achieved by the following technical solutions:
[0007] A carbon nanosheet supported Cu monatomic Pt sub-nanocluster catalyst, the catalyst taking carbon nanosheet as a carrier, Cu monatomic and Pt sub-nanocluster being independently and dispersedly anchored on the carrier.
[0008] Cu atom is anchored on the carrier in a monodispersed form, and Pt is anchored on the carrier in a sub-nanocluster form. Sub-nanocluster refers to a tiny cluster consisting of several atoms and having a size in a sub-nanometer level, the size being between 0.2-10 nm.
[0009] The second object of the application is achieved by the following technical scheme:
[0010] A preparation method of a carbon nanosheet supported Cu monatomic Pt sub-nanocluster catalyst, comprising the following steps:
[0011] (1) adding nitrogen-containing precursor and benzenetricarboxylic acid into water and stirring to obtain a suspension;
[0012] (2) adding copper-containing compound and platinum-containing compound into the suspension and stirring to obtain a precursor powder;
[0013] (3) performing heat treatment on the precursor powder under a protective gas to obtain the carbon nanosheet supported Cu monatomic Pt sub-nanocluster catalyst.
[0014] Preferably, in step (1), the mass ratio of the nitrogen-containing precursor and the benzenetricarboxylic acid is 2-50:1, and further preferably 5-20:1.
[0015] Preferably, in step (1), the mass of the nitrogen-containing precursor to the volume of the water is 1g:1-100ml, and further preferably 1g:2-20ml.
[0016] Preferably, in step (1), the stirring time is 0.5-3h, and the stirring speed is 100-800rpm.
[0017] Preferably, in step (1), the nitrogen-containing precursor comprises one or more of melamine, urea, cyanamide and dicyanediamine.
[0018] Preferably, in step (2), the mass ratio of the copper-containing compound to the platinum-containing compound is 1:(1-20), and further preferably 1:(2-8).
[0019] Preferably, in step (2), the mass ratio of the copper-containing compound to the nitrogen-containing precursor is 0.5-100:1, and further preferably 1-50:1.
[0020] Preferably, the copper-containing compound is one or more of copper acetylacetonate, copper chloride and copper nitrate.
[0021] Preferably, the platinum-containing compound is one or more of chloroplatinic acid hexahydrate, platinum chloride, and platinum nitrate.
[0022] Preferably, in step (2), the stirring time is 1-30 min, and the stirring speed is 100-800 rpm.
[0023] Preferably, in step (2), the drying comprises placing the suspension in a water bath for heating and stirring until dry into a powder, the heating time is 0.5-5 h, and the heating temperature is 60-100 DEG C.
[0024] Preferably, in step (3), the protective gas is nitrogen and / or argon, and the flow rate of the protective gas is 100-600 sccm.
[0025] Preferably, in step (3), the heat treatment comprises increasing the temperature to 800-1000 DEG C at a rate of 2-8 DEG C / min and maintaining the temperature for 1-3 h.
[0026] The third object of the application is achieved by the following technical solution:
[0027] The application provides a Cu monatomic Pt sub-nanocluster catalyst based on carbon nanosheet as a hydrogen evolution catalyst in the electrolytic production of hydrogen.
[0028] Compared with the prior art, the application has the following beneficial effects:
[0029] 1. The application provides a Cu monatomic Pt sub-nanocluster catalyst based on carbon nanosheet, wherein the catalyst uses carbon nanosheet as a carrier, and Cu monatomic and Pt sub-nanoclusters are independently dispersed and anchored on the carbon nanosheet. Cu is monodispersed on the carbon nanosheet in the form of atoms, and Pt is deposited and dispersed on the nanosheet in the form of sub-nanoclusters instead of large particles. The Cu monatomic Pt sub-nanocluster catalyst based on carbon nanosheet can be applied to hydrogen production as a hydrogen evolution catalyst.
[0030] 2. The application precisely synthesizes a bimetallic catalyst of Cu monatomic Pt sub-nanoclusters by in-situ adsorption and high-temperature pyrolysis, a large number of defect sites are formed on the surface of the prepared ultrathin carbon nanosheet, which can be used to anchor active metal monatomic, and the loading capacity is improved. Under the preparation method, the growth of Pt is controlled by adding Cu to generate atomic sub-nanoclusters instead of large particles. Meanwhile, Cu has a strong ability to promote the water dissociation step, and the catalytic activity of the catalyst in the alkaline HER reaction is improved. The electrocatalytic active material of the Pt atomic cluster and Cu monatomic anchored on the ultrathin carbon nanosheet can be applied to hydrogen production as a hydrogen evolution catalyst, and has excellent electrochemical performance under alkaline conditions.
[0031] 3、The method for preparing the carbon nanosheet loaded Cu monatomic Pt sub-nanocluster catalyst is simple and feasible, and has low cost. BRIEF DESCRIPTION OF DRAWINGS
[0032] Figure 1 A projection electron microscope image of the Cu monatomic Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheet support prepared in Example 1 of the present application;
[0033] Figure 2 A spherical aberration corrected high-resolution transmission electron microscope image of the Cu monatomic Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheet support prepared in Example 1 of the present application;
[0034] Figure 3 A projection electron microscope image of the Pt cluster catalyst based on ultra-thin carbon nanosheet support prepared in Comparative Example 2 of the present application;
[0035] Figure 4 An EDS element mapping electron microscope image of the Cu monatomic Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheet support prepared in Example 1 of the present application;
[0036] Figure 5 A hydrogen evolution linear sweep voltammetry curve of the catalyst prepared in Example 1 and Comparative Examples 1-2 of the present application in 1M KOH electrolyte;
[0037] Figure 6 A chronoamperometric stability test curve of the Cu monatomic Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheet support prepared in Example 1 of the present application. DETAILED DESCRIPTION
[0038] The technical solutions of the present application will be further described and illustrated by specific examples and drawings. It should be understood that the specific examples described herein are only used to help understand the present application, and are not used to limit the specific scope of the present application. The drawings used herein are only used to better illustrate the disclosed content of the present application, and do not limit the scope of protection. If not otherwise specified, the raw materials used in the examples of the present application are all commonly used raw materials in the art, and the methods used in the examples are all conventional methods in the art.
[0039] Example 1
[0040] The present embodiment is a preparation method of a Cu monatomic Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheet support, which comprises the following steps:
[0041] (a) 1 mg of dicyandiamide powder and 0.1 mg of benzene tricarboxylic acid powder were added to 5 ml of deionized water and stirred at 500 rpm for 0.5 h until white, to obtain a white suspension;
[0042] (b) 5 mg copper acetylacetonate and 20 mg chloroplatinic acid hexahydrate were added to the above suspension and stirred at 500 rpm for 10 min, and the obtained mixture was heated to 80°C in a water bath and stirred vigorously for 0.5 h until dryness to obtain a precursor powder;
[0043] (c) The precursor powder was heated to 900°C at a rate of 5°C / min under the protection of 300 sccm argon gas and kept for 2 h to obtain the Cu single atom Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheets.
[0044] The Cu single atom Pt sub-nanocluster catalyst based on carbon nanosheets prepared above was subjected to transmission electron microscopy scanning, and the transmission electron microscopy image is shown in Figure 1 It can be seen that the ultra-thin carbon nanosheets still maintain the morphology of nanosheets, and no metal nanoparticles are visible during pyrolysis, and the SAED shows an amorphous structure.
[0045] The Cu single atom Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheets prepared above was subjected to spherical aberration-corrected high-resolution transmission electron microscopy observation, and the observation results are shown in Figure 2 It can be seen that many diffusely distributed atomic images can be observed on the surface of the carbon nanosheets, and some atoms gather together to form sub-nanoclusters.
[0046] It can be seen from Figure 4 that the EDS element mapping image further confirms that Pt is mainly in the form of atomic clusters, and Cu appears in the form of single atoms randomly on the carbon nanosheets.
[0047] Example 2
[0048] The present embodiment is a preparation method of a Cu single atom Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheets, which comprises the following steps:
[0049] (a) 0.6 mg of dicyandiamide powder and 0.05 mg of benzene tricarboxylic acid powder were added to 3 ml of deionized water and stirred at 400 rpm for 1 h until white, to obtain a white suspension;
[0050] (b) 4 mg of copper acetylacetonate and 30 mg of chloroplatinic acid hexahydrate were added to the above suspension and stirred at 400 rpm for 8 min, and the obtained mixture was heated to 70°C in a water bath and stirred vigorously for 0.5 h until dryness to obtain a precursor powder;
[0051] (c) The precursor powder was heated to 850°C at a rate of 4°C / min under the protection of 200 sccm argon gas and kept for 3 h to obtain the Cu single atom Pt sub-nanocluster catalyst based on ultra-thin carbon nanosheets.
[0052] Example 3
[0053] The present example is a preparation method of a carbon nanosheet supported Cu monatomic Pt sub-nanocluster catalyst, which comprises the following steps:
[0054] (a) 1.5 mg of dicyandiamide powder and 0.2 mg of benzene tricarboxylic acid powder were added to 8 ml of deionized water and stirred at 600 rpm for 1 h until white, obtaining a white suspension;
[0055] (b) 8 mg of copper nitrate and 40 mg of chloroplatinic acid hexahydrate were added to the above suspension and stirred at 600 rpm for 5 min, and the obtained mixture was heated to 90°C in a water bath and stirred vigorously for 1 h until dry, obtaining a precursor powder;
[0056] (c) The precursor powder was heated to 950°C at a rate of 6°C / min under the protection of 400 sccm of argon gas and kept for 1.5 h, obtaining the carbon nanosheet supported Cu monatomic Pt sub-nanocluster catalyst.
[0057] Comparative Example 1
[0058] Comparative Example 1 is a preparation method of a carbon nanosheet supported Cu monatomic catalyst, which comprises the following steps:
[0059] (a) 1 mg of dicyandiamide powder and 0.1 mg of benzene tricarboxylic acid powder were added to 5 ml of deionized water and stirred at 500 rpm for 0.5 h until white, obtaining a white suspension;
[0060] (b) 5 mg of copper acetylacetonate was added to the above suspension and stirred at 500 rpm for 10 min, and the obtained mixture was heated to 80°C in a water bath and stirred vigorously for 0.5 h until dry, obtaining a precursor powder;
[0061] (c) The precursor powder was heated to 900°C at a rate of 5°C / min under the protection of 300 sccm of argon gas and kept for 2 h, obtaining the carbon nanosheet supported Cu monatomic catalyst.
[0062] Comparative Example 2
[0063] Comparative Example 2 is a preparation method of a carbon nanosheet supported Pt cluster catalyst, which comprises the following steps:
[0064] (a) 1 mg of dicyandiamide powder and 0.1 mg of benzene tricarboxylic acid powder were added to 5 ml of deionized water and stirred at 500 rpm for 0.5 h until white, obtaining a white suspension;
[0065] (b) 20 mg of chloroplatinic acid hexahydrate was added to the above suspension and stirred at 500 rpm for 10 min, and the obtained mixture was heated to 80 °C in a water bath and stirred vigorously for 0.5 h until dryness to obtain a precursor powder;
[0066] (c) The precursor powder was heated to 900 °C at a rate of 5 °C / min under the protection of 300 sccm argon gas and kept for 2 h to obtain the Pt particle catalyst based on ultrathin carbon nanosheet.
[0067] In the catalyst preparation process of Comparative Example 2, no copper acetylacetonate was added, and Cu was lacking to regulate the growth of Pt, so that Pt finally formed large clusters of large particles (about 20 nm in size) instead of sub-nanoclusters, as shown in Figure 3 .
[0068] Comparative Example 3
[0069] Comparative Example 3 is a preparation method of a Pt cluster catalyst based on ultrathin carbon nanosheet, which comprises the following steps:
[0070] (a) 1 mg of dicyandiamide powder and 0.1 mg of benzene tricarboxylic acid powder were added to 5 ml of deionized water and stirred at 500 rpm for 0.5 h until white, to obtain a white suspension;
[0071] (b) 25 mg of chloroplatinic acid hexahydrate was added to the above suspension and stirred at 500 rpm for 10 min, and the obtained mixture was heated to 80 °C in a water bath and stirred vigorously for 0.5 h until dryness to obtain a precursor powder;
[0072] (c) The precursor powder was heated to 900 °C at a rate of 5 °C / min under the protection of 300 sccm argon gas and kept for 2 h to obtain the Pt particle catalyst based on ultrathin carbon nanosheet.
[0073] The catalysts prepared in Example 1 and Comparative Examples 1-3 were tested for hydrogen evolution in 1M KOH electrolyte. As can be seen from Figure 5 , when the catalyst of the water electrolysis test system is the Cu monatomic Pt sub-nanocluster catalyst based on ultrathin carbon nanosheet prepared in Example 1 of the present application, only a low overpotential of 177.2 mV is required to make the current density of the reaction system reach 500 mA / cm -2 , which is significantly better than the Cu monatomic catalyst (350.9 mV), the Pt particle catalyst (251.2 mV) and the commercial platinum carbon catalyst (221.1 mV). At the same time, with the increase of current density, the advantage of the Cu monatomic Pt sub-nanocluster catalyst is more and more obvious.
[0074] In Comparative Example 3, the amount of chloroplatinic acid hexahydrate added was increased, and the final Pt loading was increased. However, in the absence of Cu, the more Pt was loaded, the more Pt was deposited on the carbon nanosheets in the form of larger particles. The Pt clusters reduced the catalytic performance, and a low overpotential of 330 mV was required to achieve a current density of 500 mA / cm -2 .
[0075] The stability of the Cu monatomic Pt sub-nanocluster catalyst based on ultrathin carbon nanosheets prepared in Example 1 was tested by chronoamperometric stability test, and the test results are shown in Figure 6 As can be seen, under a large current density of 500 mA / cm -2 , the Cu monatomic Pt sub-nanocluster catalyst based on ultrathin carbon nanosheets in this example can ensure almost no decay of catalytic activity within 1400 h, and the potential degradation rate is only 7.35 μV h -1 . This shows that the catalyst has excellent industrial application and practical use potential.
[0076] Aspects, embodiments, features, of the present application should be considered illustrative of all aspects, embodiments, features, of the present application and are not restrictive of the present application, the scope of which is only limited by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art, in which the spirit of the application lies, without departing from the spirit and scope of the claimed application.
[0077] In the preparation method of the present application, the order of the steps is not limited to the order listed, and for those skilled in the art, the order of the steps can be changed without creative labor, and the changes are within the protection scope of the present application. In addition, two or more steps or actions can be performed simultaneously.
[0078] Finally, it should be noted that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the embodiments of the present application. Those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace them. Here, it is not necessary or possible to fully exemplify all embodiments. However, these obvious changes or variations within the spirit of the present application still fall within the protection scope of the present application, and any additional limitation is contrary to the spirit of the present application.
Claims
1. A catalyst based on Cu single-atom Pt sub-nano clusters supported on carbon nanosheets, characterized in that, The catalyst uses carbon nanosheets as a support, with Cu single atoms and Pt sub-nano clusters independently and dispersedly anchored on the support.
2. A method for preparing a catalyst based on Cu single-atom Pt sub-nano clusters supported on carbon nanosheets, characterized in that, The preparation method includes the following steps: (1) Add nitrogen-containing precursor and benzoic acid to water and stir to obtain a suspension; (2) Add the copper-containing compound and the platinum-containing compound to the above suspension and stir well, then dry to obtain the precursor powder; (3) The precursor powder is heat-treated under a protective gas to obtain the catalyst based on carbon nanosheets supported on Cu single-atom Pt sub-nano clusters.
3. The preparation method according to claim 2, characterized in that, In step (1), the mass ratio of nitrogen-containing precursor to benzoic acid is 2 to 50:
1.
4. The preparation method according to claim 2, characterized in that, In step (1), the ratio of the mass of the nitrogen-containing precursor to the volume of water is 1g: 1~100ml.
5. The preparation method according to claim 2, characterized in that, The nitrogen-containing precursor includes one or more of melamine, urea, cyanamide, and dicyandiamide; The copper-containing compound is one or more of copper acetylacetonate, copper chloride, and copper nitrate. The platinum-containing compound is one or more of chloroplatinic acid hexahydrate, platinum chloride, and platinum nitrate.
6. The preparation method according to claim 2, characterized in that, In step (2), the mass ratio of the copper-containing compound to the platinum-containing compound is 1:(1-20).
7. The preparation method according to claim 2, characterized in that, In step (2), drying includes: placing the suspension in a water bath for heating and stirring until it is dried into powder, with a heating time of 0.5 to 5 hours and a heating temperature of 60 to 100°C.
8. The preparation method according to claim 2, characterized in that, In step (3), the protective gas is nitrogen and / or argon, and the flow rate of the protective gas is 100 to 600 sccm.
9. The preparation method according to claim 2, characterized in that, In step (3), the heat treatment includes: heating to 800-1000℃ at a rate of 2-8℃ / min and holding at that temperature for 1-3 hours.
10. The application of a carbon nanosheet-supported Cu single-atom Pt sub-nano cluster catalyst prepared by the preparation method as described in claim 1 or claim 2 as a hydrogen evolution catalyst in water electrolysis for hydrogen production.