Preparation method of single-site selenium-modified platinum wrinkled nanoparticle catalyst

Abstract

The present invention relates to the technical field of new energy materials and the field of electrocatalytic water splitting, and specifically to a single-site selenium-modified platinum wrinkled nanoparticle catalyst, a preparation method, and an application. The present invention obtains amorphous PtSe2 WNPs by a hydrothermal method and forms a unique non-metallic single-site structure through a subsequent heat treatment process to obtain a Pt-based nanomaterial rich in single-atom selenium. A strong interaction occurs between the single-site Se and the adjacent Pt atoms, causing the Pt to be in an electron-deficient state, thereby optimizing the adsorption and desorption of reaction intermediates on the Pt site and reducing the dissociation energy barrier of water molecules on the Pt site, ultimately improving the alkaline HOR / HER catalysis of the Pt-based nanomaterial. In addition, the Pt-based nanomaterial produces a defective structure, thereby controlling the activation of reactants and the adsorption and desorption of intermediates in the catalytic reaction, and promoting the kinetic process of hydrogen evolution reaction and hydrogen oxidation reaction under alkaline conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy materials and the field of electrocatalytic water splitting, and in particular to a single-site selenium-modified platinum wrinkled nanoparticle catalyst, a preparation method and an application thereof. Background Art

[0002] Against the backdrop of increasing energy demand and worsening environmental problems, it is urgent to explore green energy to replace traditional fossil fuels. Therefore, finding new, efficient, and environmentally friendly energy sources is an important way to solve the energy crisis. A series of clean energy sources such as wind energy, solar energy, tidal energy, geothermal energy, and hydrogen energy have attracted much attention. Among the many clean energy sources, hydrogen energy, as an ideal secondary energy source, has many advantages such as high energy density, clean and pollution-free combustion products, and abundant sources. It is considered to be the best energy carrier to replace fossil energy. Hydrogen energy can be generated by driving water decomposition through sustainable electricity. At the same time, hydrogen can produce electricity through hydrogen oxidation reaction in fuel cells, thereby realizing efficient storage and conversion of hydrogen energy. Therefore, HER and HOR are the core electrochemical reactions of the hydrogen economy.

[0003] To date, platinum (Pt)-based materials are considered to be the most efficient catalysts for hydrogen evolution and hydrogen oxidation in water electrolysis due to their optimal binding ability with hydrogen. Especially under strong acidic conditions, their overpotential is almost negligible, which is due to their ability to bind to hydrogen intermediates (H ads ) has a relatively ideal bonding strength. However, the electrocatalytic water splitting hydrogenation reaction and hydrogen oxidation reaction of platinum-based catalysts face serious reaction kinetic problems in alkaline environments. Because compared with acidic conditions, H + At lower concentrations, the reaction rate is approximately two to three orders of magnitude lower than under acidic conditions, resulting in very slow reaction kinetics, which in turn inhibits both the hydrogen evolution reaction and the hydrogen oxidation reaction. Studies have shown that this significant difference in activity is due to the poor water dissociation ability of the Pt surface. Consequently, the design and development of high-performance platinum-based bifunctional hydrogen electrocatalysts for alkaline hydrogen evolution and hydrogen oxidation has become a research hotspot. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a single-site selenium-modified platinum wrinkled nanoparticle catalyst, a preparation method and an application.

[0005] The first aspect of the present invention provides a method for preparing a single-site selenium-modified platinum wrinkled nanoparticle catalyst, which comprises the following steps:

[0006] S1: Platinum source, selenium source, polyvinyl pyrrolidone, hydrazine hydrate and deionized water are mixed to form a uniform mixed solution, which is then transferred to a reactor for hydrothermal reaction. Finally, platinum diselenide wrinkled nanoparticles (PtSe2WNPs) are obtained by centrifugation, washing and drying.

[0007] S2: The PtSe2WNPs obtained in step S1 are loaded onto carbon black, and then heat-treated to obtain single-site selenium-modified platinum wrinkled nanoparticle catalyst SS Se-Pt WNPs.

[0008] In step S1, the platinum source and selenium source are Pt and Se element precursors, PVP is an active agent, hydrazine hydrate and ultrapure water are solvents, and amorphous PtSe2WNPs nanoparticles are obtained by a hydrothermal method.

[0009] Preferably, in step S1, the platinum source is tetraammineplatinum nitrate; and the selenium source is selenious acid.

[0010] Preferably, in step S1, the temperature of the hydrothermal reaction is 160-200° C., and the time of the hydrothermal reaction is 10-14 h.

[0011] Preferably, in step S1, the washing operation is specifically washing the product three times with a mixed solution of acetone and ethanol.

[0012] Preferably, in step S2, the carbon black is specifically Vulcan XC72R carbon.

[0013] Preferably, in step S2, the PtSe2WNPs and carbon black are dispersed and ultrasonically uniformly dispersed with ethanol respectively, and then the two are mixed together, and then centrifuged and dried, so that the PtSe2WNPs are loaded on the carbon black.

[0014] Preferably, in step S2, the heat treatment method is a calcination method, the calcination temperature is 250°C, the calcination time is 1 hour, and the calcination atmosphere is air.

[0015] The second aspect of the present invention provides a single-site selenium-modified platinum wrinkled nanoparticle catalyst prepared by the preparation method described above.

[0016] The third aspect of the present invention provides the use of the single-site selenium-modified platinum wrinkled nanoparticle catalyst described above for electrocatalytic alkaline HER / HOR.

[0017] The present invention uses a hydrothermal method to obtain amorphous PtSe2WNPs. This is combined with a subsequent heat treatment process to form a unique non-metallic single-site structure, resulting in a Pt-based nanomaterial rich in single-atom selenium (Se). Strong interactions occur between the single-site Se and adjacent Pt atoms, leaving the Pt in an electron-deficient state. This optimizes the adsorption and desorption of reaction intermediates at the Pt site and reduces the dissociation barrier of water molecules at the Pt site, ultimately enhancing the alkaline HOR / HER catalytic performance of the Pt-based nanomaterial.

[0018] This invention provides a method for preparing a non-metallic single-site selenium-modified platinum wrinkled nanoparticle catalyst. This method creates defect structures in the Pt-based nanomaterial, thereby controlling the activation of reactants and the adsorption and desorption of intermediate species during catalytic reactions, and promoting the kinetics of hydrogen evolution and hydrogen oxidation reactions under alkaline conditions. Furthermore, this invention opens up new prospects for the design and development of high-efficiency electrocatalysts based on non-metallic single-site nanomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0020] Figure 1 Schematic diagram of transmission electron microscopy (TEM) images of PtSe2WNPs prepared in Example 1 of the present invention at different magnifications;

[0021] Figure 2 is a schematic diagram of a transmission electron microscopy (TEM) image of the SS Se-Pt WNPs catalyst prepared in Example 1 of the present invention;

[0022] Figure 3 Schematic diagram of a high-resolution transmission electron microscopy (HRTEM) image and a Fourier transform image (FFT) image of the SS Se-Pt WNPs catalyst prepared in Example 1 of the present invention;

[0023] Figure 4 Schematic diagram of the X-ray diffraction pattern (XRD) and scanning electron microscope energy dispersive spectrum (SEM-EDS) of the PtSe2WNPs electrocatalytic material prepared in Example 1 of the present invention;

[0024] Figure 5 Schematic diagram of the X-ray diffraction pattern (XRD) and scanning electron microscope energy dispersive spectrum (SEM-EDS) of the SS Se-Pt WNPs electrocatalytic material prepared in Example 1 of the present invention;

[0025] Figure 6 is a schematic diagram of the energy dispersive spectrometer (EDS) of the SS Se-Pt WNPs electrocatalytic material prepared in Example 1 of the present invention;

[0026] Figure 7Schematic diagrams of the Pt L-edge X-ray absorption near-edge structure (XANES) graph (a) and Fourier transform X-ray absorption fine structure (FT-EXAFS) graph (b) of SS Se-Pt WNPs, PtO2 and Pt foil prepared in Example 1 of the present invention, and the Se K-edge X-ray absorption near-edge structure (XANES) graph (c) and Fourier transform X-ray absorption fine structure (FT-EXAFS) graph of SSSe-Pt NBs, SeO2a and Se mesh;

[0027] Figure 8 Schematic diagram of the HER polarization curve (a), Tafel slope diagram (b), mass activity diagram (c), and HOR polarization curve (d) of SS Se-Pt WNPs, PtSe2 WNPs, and Pt / C prepared in Example 1 of the present invention;

[0028] Figure 9 The SS Se-Pt WNPs prepared in Example 1 of the present invention were 10 mA cm in 0.1 M KOH solution. -2 Schematic diagram of the stability curve of hydrogen released by water splitting. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0030] Example 1

[0031] S1. Preparation of PtSe2WNPs

[0032] 9.7 mg of tetraammine platinum nitrate, 6.5 mg of selenious acid, and 50 mg of polyvinylpyrrolidone (PVP) were uniformly dispersed in ultrapure water, and then 0.1 mL of hydrazine hydrate was added and ultrasonicated to form a uniform mixed solution. The solution was then transferred to a reactor and hydrothermally reacted at 180°C for 12 hours. The reacted material was centrifuged, washed three times, and dried to obtain platinum diselenide wrinkled nanoparticles (PtSe2WNPs).

[0033] S2. Preparation of SS Se-Pt WNPs

[0034] The PtSe2WNPs and carbon black obtained in step S1 were dispersed evenly in ethanol and then mixed together. The mixture was then centrifuged and dried to load the PtSe2WNPs onto the carbon black. The dried product was then calcined at 250°C in air for 1 hour to obtain a single-site selenium-modified platinum wrinkled nanoparticle catalyst (SS Se-Pt WNPs).

[0035] like Figure 1 Figure 1 shows the morphology of the PtSe2WNPs prepared in Example 1. (a) High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and (b) Transmission electron microscopy (TEM). (a) shows that the obtained PtSe2WNPs have a high morphology yield; (b) shows that the PtSe2WNPs are wrinkled nanoparticles.

[0036] like Figure 2 Figure 2 shows a high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) image of the SS Se-Pt WNPs catalyst prepared in Example 1. The image shows that the SS Se-Pt WNPs are still uniformly dispersed on the carbon black after calcination, demonstrating its excellent morphological stability.

[0037] like Figure 3 As shown in the high-resolution transmission electron micrograph of the SS Se-Pt WNPs catalyst prepared in Example 1, the lattice spacings of the platinum (111) and (200) planes are 0.23 nm and 0.20 nm, respectively. In addition, the fast Fourier transform (FFT) image of the SS Se-Pt WNPs shows good crystallinity under the exposed (111) and (200) planes along the

[011] zone axis.

[0038] like Figure 4 Figures 2 and 3 show powder X-ray diffraction (PXRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) patterns of the PtSe2WNPs electrocatalytic material prepared in Example 1. Figure (a) shows that the PtSe2WNPs are amorphous. Figure (b) shows that the Pt / Se atomic ratio is 34.5 / 65.5.

[0039] like Figure 5 Figure 2 shows the powder X-ray diffraction (PXRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) patterns of the SS Se-Pt WNPs electrocatalytic material prepared in Example 1. (a) shows that the characteristic peaks at 40°, 46°, and 67° correspond to the (111), (200), and (220) crystal planes of Pt (PDF#04-0802), respectively, and no characteristic peaks of selenium were detected. (b) shows that the atomic ratio of Pt / Se is 95.3 / 4.7. These results indicate that selenium volatilized during the heat treatment and that the SS Se-Pt WNPs electrocatalytic material was successfully prepared.

[0040] like Figure 6As shown, the scanning transmission electron microscopy-energy dispersive spectroscopy (STEM-EDS) elemental mapping of the SS Se-Pt WNPs electrocatalytic material prepared in Example 1. The figure shows that the platinum and selenium elements in the SS Se-Pt WNPs are uniformly distributed.

[0041] Application Examples

[0042] The SS Se-Pt WNPs electrocatalytic material obtained in Example 1 was used to test the performance of electrocatalytic water splitting hydrogen evolution (HER) and hydrogen oxidation (HOR) using a three-electrode system. The specific treatment method was as follows: SS Se-Pt WNPs were used as the working electrode, a carbon rod was used as the counter electrode, and mercury / mercuric oxide was used as the reference electrode. A linear voltammetric sweep test was performed in 0.1M KOH electrolyte to evaluate the HER and HOR performance.

[0043] The samples used were SS Se-Pt WNPs, PtSe2 WNPs and Pt / C prepared in Example 1. Figure 8 It can be seen that PtSe2WNPs has the worst electrocatalytic performance, while SS Se-Pt WNPs has the best performance, which is superior to commercial Pt / C.

[0044] SS Se-Pt WNPs at 10 mA cm -2 The overpotential of SS Se-Pt WNPs is 58 mV, which is superior to that of commercial Pt / C (86.5 mV). Moreover, the HOR performance of SS Se-Pt WNPs is also superior to that of commercial Pt / C, with a mass activity of 1104 mA mg at an overpotential of 50 mV. -1 Pt .

[0045] like Figure 9 As shown, the SS Se-Pt WNPs in 0.1 M KOH solution at 10 mA cm -2 The catalytic performance of hydrogen decomposition by water splitting is very stable.

[0046] This demonstrates that the SS Se-Pt WNPs electrocatalytic material of the present invention has excellent water electrolysis performance and can be used in the field of electrocatalytic alkaline HER / HOR.

[0047] The applicant declares that the above disclosure is only the preferred technical solution of the present invention and should not be regarded as limiting the scope of the present invention. Therefore, equivalent changes made by those skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention.

[0048] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing a single-site selenium-modified platinum wrinkled nanoparticle catalyst, characterized in that: The specific steps are as follows: S1: Platinum source, selenium source, polyvinyl pyrrolidone, hydrazine hydrate and deionized water are mixed to form a uniform mixed solution, which is then transferred to a reactor for hydrothermal reaction. Finally, platinum diselenide wrinkled nanoparticles (PtSe2WNPs) are obtained by centrifugation, washing and drying. S2: The PtSe2 WNPs obtained in step S1 are loaded onto carbon black, and then subjected to heat treatment to obtain single-site selenium-modified platinum wrinkled nanoparticle catalyst SS Se-Pt WNPs; The temperature of the hydrothermal reaction is 160-200°C, and the time of the hydrothermal reaction is 10-14 hours; In step S2, the heat treatment is calcining at 250° C. for 1 hour in an air atmosphere.

2. The method for preparing a single-site selenium-modified platinum wrinkled nanoparticle catalyst according to claim 1, characterized in that: In step S1, the platinum source is tetraammineplatinum nitrate, and the selenium source is selenious acid.

3. The method for preparing a single-site selenium-modified platinum wrinkled nanoparticle catalyst according to claim 1, characterized in that: In step S1, the specific operation of washing is to wash the product three times with a mixed solution of acetone and ethanol.

4. The method for preparing a single-site selenium-modified platinum wrinkled nanoparticle catalyst according to claim 1, characterized in that: In step S2, the carbon black is specifically Vulcan XC72R carbon.

5. The method for preparing a single-site selenium-modified platinum wrinkled nanoparticle catalyst according to claim 1, characterized in that: In step S2, the PtSe2 WNPs and carbon black are dispersed and ultrasonically uniformly dispersed with ethanol respectively, and then the two are mixed together, and then centrifuged and dried to load the PtSe2 WNPs onto the carbon black. 6 . The single-site selenium-modified platinum wrinkled nanoparticle catalyst prepared by the preparation method according to claim 1 . 7 . Use of the single-site selenium-modified platinum wrinkled nanoparticle catalyst according to claim 6 in electrocatalytic alkaline HER or electrocatalytic alkaline HOR.

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