Low-platinum hydrogen evolution electrocatalyst based on polyacid-carbon dot composite carrier as well as preparation method and application of low-platinum hydrogen evolution electrocatalyst
By loading platinum nanoparticles onto a multi-acid-carbon dot composite support, the problems of high cost and poor stability of platinum-based catalysts were solved, achieving a highly efficient and stable hydrogen production reaction through water electrolysis. This approach reduced the platinum loading and improved the catalyst's performance and lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHEAST NORMAL UNIVERSITY
- Filing Date
- 2026-01-30
- Publication Date
- 2026-04-14
AI Technical Summary
Existing platinum-based catalysts are expensive due to their high platinum loading, and the platinum particles are prone to agglomeration and detachment, resulting in poor stability, which limits the commercial application of water electrolysis hydrogen production technology.
A multi-acid-carbon dot composite support was constructed by means of the synergistic effect of multi-acid and carbon dots to build a composite support with strong anchoring ability and high conductivity. Platinum nanoparticles with ultra-low content were loaded onto the support to form a platinum-multi-acid-carbon dot composite electrocatalyst. The oxygen atoms of the multi-acid were used as molecular anchors to stabilize the platinum nanoparticles and optimize their electronic structure.
It significantly reduced the platinum loading, improved the stability and activity of the catalyst, reduced hydrogen production energy consumption, extended the catalyst lifespan, reduced material costs, and improved the efficiency and reliability of hydrogen production by water electrolysis.
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Figure CN121852998A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrocatalytic reaction technology, specifically relating to a low-platinum hydrogen evolution electrocatalyst based on a multi-acid-carbon dot composite support, its preparation method, and its application. Background Technology
[0002] Hydrogen energy, as a clean and efficient secondary energy source, is key to the future transformation of the energy structure. Among various hydrogen production technologies, water electrolysis has attracted much attention due to its clean process and high product purity. Specifically, in the electrolyzer of this technology, the hydrogen evolution reaction occurring at the cathode is one of the key steps limiting overall energy efficiency and cost.
[0003] Currently, the most commercially effective catalysts for hydrogen evolution reaction are platinum-based catalysts. Platinum has moderate adsorption energy for hydrogen intermediates and exhibits excellent catalytic activity and stability. However, platinum is a precious metal, scarce in the Earth's crust and expensive. Its high cost directly increases the investment and operating expenses of water electrolysis hydrogen production equipment, seriously hindering the large-scale commercialization of this technology.
[0004] To reduce the amount of platinum used, existing technologies mainly employ two strategies: First, platinum is made into nanoscale or even single-atom form and dispersed on a support with a high specific surface area (such as carbon black, graphene, carbon nanotubes, etc.) to maximize the exposure of active sites and improve the utilization rate of platinum atoms; Second, a support material that can interact strongly with platinum and also has certain catalytic activity or promotes electron transport is sought to synergistically improve the overall catalytic performance.
[0005] Despite the progress made in the above studies, the following problems and shortcomings still exist: most of the reported low-platinum catalysts still have high platinum loading, and the cost reduction is limited, which is still far from large-scale application; in addition, the stability of the catalyst needs to be improved. This is because the interaction between the traditional support and metallic platinum is weak, which leads to the easy migration, aggregation, and detachment of platinum nanoparticles during long-term water electrolysis hydrogen evolution tests, resulting in catalytic performance degradation.
[0006] Therefore, developing a novel electrocatalyst that can maintain high intrinsic activity and possess excellent structural stability and durability under low platinum loading is of great significance for promoting the practical application of water electrolysis to produce hydrogen. Summary of the Invention
[0007] The purpose of this invention is to provide a low-platinum hydrogen evolution electrocatalyst based on a polyacid-carbon dot composite support, its preparation method, and its application. The aim is to construct a composite support with both strong platinum anchoring ability and high conductivity through the synergistic effect of polyacids and carbon dots, so as to solve the core problems of high cost due to high platinum loading and poor stability due to easy agglomeration and shedding of platinum particles in existing platinum-based catalysts.
[0008] On the one hand, this invention provides a method for preparing a low-platinum hydrogen evolution electrocatalyst based on a multi-acid-carbon dot composite support, employing the following technical solution: The preparation method of low-platinum hydrogen evolution electrocatalyst based on multi-acid-carbon dot composite support includes the following steps: 1) Provide an aqueous solution of carbon dots and a polyacid solution, mix and stir to obtain a polyacid-carbon dot composite carrier solution; 2) Provide a platinum precursor solution and mix it with the polyacid-carbon dot composite carrier solution prepared in step 1), stir until homogeneous, and obtain a mixed solution; 3) The mixed solution obtained in step 2) is concentrated and dried to obtain solid precursor powder; 4) Under a reducing atmosphere, the solid precursor powder obtained in step 3) is heat-treated to obtain a low-platinum hydrogen evolution electrocatalyst.
[0009] Preferably, in step 1), the concentration of the carbon dot aqueous solution is 0.12 mg / mL; and the mixing and stirring time is 0.5-12 h.
[0010] Preferably, in step 1), the polyacid solution is any one of Keggin type polyacid, Dawson type polyacid, or Anderson type polyacid.
[0011] Preferably, in step 2), the platinum precursor in the platinum precursor solution is any one of platinum acetylacetonate, chloroplatinic acid, and sodium chloroplatinate; The solvent for the platinum precursor solution is acetonitrile.
[0012] Preferably, in step 2), the stirring time is 0.5-12 hours.
[0013] Preferably, in step 4), the reducing atmosphere is a hydrogen-argon mixture with a hydrogen gas fraction of 10%; the heat treatment temperature is 200°C and the heat treatment time is 2 hours.
[0014] On the one hand, the present invention also provides a low-platinum hydrogen evolution electrocatalyst based on a multi-acid-carbon dot composite support prepared by the above preparation method, using the following technical solution: Low-platinum hydrogen evolution electrocatalysts based on multi-acid-carbon dot composite supports include: Polyacid-carbon dot composite carrier; Platinum nanoparticles loaded on the polyacid-carbon dot composite support; The platinum nanoparticles have a loading of less than 2 wt% and a size of less than 3 nm.
[0015] Furthermore, the present invention also provides the application of the low-platinum hydrogen evolution electrocatalyst based on the multi-acid-carbon dot composite support prepared by the above preparation method in the hydrogen evolution reaction of water electrolysis.
[0016] In summary, the present invention has the following beneficial technical effects: 1. This invention constructs a composite support with both strong anchoring ability and high conductivity by combining polyacids and carbon dots. Then, ultra-low content platinum nanoparticles are loaded onto this support to prepare a highly efficient and stable electrocatalyst for the hydrogen evolution reaction (HER). When this platinum-polyacid-carbon dot composite electrocatalyst is applied to the HER reaction of water electrolysis, it achieves high current density and high efficiency hydrogen evolution at low overpotentials. Specifically, the three-dimensional interconnected conductive network formed by carbon dots provides a pathway for rapid charge transport and provides a dispersion framework for polyacids with its abundant surface functional groups. Polyacids are highly dispersed on this framework, and their surface oxygen atoms act as strong "molecular anchors," firmly capturing and stabilizing platinum nanoparticles through coordination, effectively preventing their migration, aggregation, and loss at high potentials. Simultaneously, the strong interfacial electronic interactions between polyacids and carbon dots, and their synergistic effect with platinum nanoparticles, jointly modulate the electronic structure of the platinum active center, optimizing its adsorption free energy for hydrogen intermediates, thereby significantly improving intrinsic catalytic activity.
[0017] 2. This invention successfully reduces the platinum loading to an ultra-low level of less than 2 wt% through the synergistic anchoring and dispersing effect of the multi-acid-carbon dot composite support, which is far lower than that of commercial platinum-carbon catalysts (typically >20 wt%). This significantly reduces the dependence on the precious metal platinum and the material cost, removing a key cost barrier for the large-scale commercialization of hydrogen production by water electrolysis.
[0018] 3. Due to the interfacial effect between the polyacid and carbon dots, and its synergistic effect with platinum, the electronic structure of the platinum active sites is modulated, optimizing the adsorption energy for hydrogen intermediates. The catalyst of this invention exhibits significantly superior mass activity and specific activity compared to commercial 20% Pt / C catalysts in the hydrogen evolution reaction, at 10 mA·cm⁻¹. -2 The overpotential at current density is as low as 17 mV, which means lower energy consumption at the same hydrogen production rate, or a faster hydrogen production rate at the same voltage, directly reducing the operating cost of hydrogen production; at an overpotential of 100 mV, its mass activity is as high as 4.42 A·mg. -1 This means that energy consumption is significantly reduced at the same hydrogen production rate.
[0019] 4. This invention effectively inhibits the migration, Ostwald ripening, and detachment of platinum nanoparticles during the reaction process through a unique "multi-acid molecular anchor" and carbon dot conductive network structure. The catalyst prepared by this invention exhibits minimal performance degradation after 100 hours of constant potential testing and 3000 cyclic voltammetry tests, significantly extending the catalyst's lifespan.
[0020] 5. The catalyst of this invention not only performs excellently in the three-electrode system test, but also exhibits superior performance and stability in the PEM device for proton exchange membrane water electrolysis. Specifically, based on Pt-SiW 12 The film electrode prepared by -CDs can achieve an industrial-grade current density of 1 A·cm⁻¹. -2 2A·cm -2 and 3A·cm -2 The battery operating voltages are 1.61V, 1.72V and 1.82V respectively, which means that in the actual process of water electrolysis to produce hydrogen, the power consumption is greatly reduced, directly improving the energy conversion efficiency and economy.
[0021] 6. This invention is in 2A·cm -2 After running continuously for 1200 hours at a current density, its performance degradation is negligible. This is due to the strong anchoring effect of the composite carrier on the platinum nanoparticles, which effectively inhibits their aggregation and loss in a strongly acidic environment and under high current density, ensuring the device's ultra-long service life and operational reliability.
[0022] 7. The preparation method employed in this invention has a simple process, low equipment requirements, and requires no complex post-processing steps, making it easy to control and scale up production. Carbon point aqueous solutions are widely available, inexpensive, and environmentally friendly; polyacids are also mature chemical reagents. The entire preparation process avoids the use of toxic and harmful reagents or the generation of large amounts of pollution, conforming to the principles of green chemistry. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the preparation route of the low-platinum hydrogen evolution electrocatalyst based on a multi-acid-carbon dot composite support in Example 1 of the present invention. Figure 2 The image shows an X-ray diffraction (XRD) image of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention. Figure 3 Image a is a transmission electron microscope (TEM) characterization image of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 3 Image b is a transmission electron microscope (TEM) characterization image of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 3 Image c is a high-resolution transmission electron microscope (HRTEM) characterization image of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 4 This is an EDS elemental distribution diagram of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of the present invention; Figure 5 In Figure a, the high-resolution Pt 4f XPS spectrum of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention is shown. Figure 5 b is the high-resolution W4f XPS spectrum of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 5 c is the high-resolution O 1s XPS spectrum of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 5 The image in d is the high-resolution C1s XPS spectrum of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 6 The low platinum hydrogen evolution electrocatalyst in Example 2 of this invention and Comparative Example 1 were used at 0.1~-0.1 V vs. RHE at 5 mV·s. -1 Linear scan voltammetry curves measured in 0.5 MH2SO4 electrolyte at a scan rate of [value missing]; Figure 7 The graph shows the mass activity and specific activity of the low-platinum hydrogen evolution electrocatalyst in Example 2 of this invention and Comparative Example 1. Figure 8 The circuit test diagrams are shown for the low platinum hydrogen evolution electrocatalyst in Example 2 of the present invention and Comparative Example 1. Figure 9 The stability test results are shown for the low platinum hydrogen evolution electrocatalyst in Example 2 of this invention and Comparative Example 1. Figure 10 The current-voltage polarization curve of the PEM electrolysis device at 80°C for the low platinum hydrogen evolution electrocatalyst membrane electrode in Example 2 of this invention; Figure 11 This is the time-voltage curve of the PEM electrolysis device at 80°C for the ground wave hydrogen evolution electrocatalyst membrane electrode in Example 2 of the present invention. Detailed Implementation
[0024] The following examples, comparative examples, and appendices are used in conjunction with the embodiments. Figure 1-11 The present invention will be described in further detail below.
[0025] Example Example 1 Reference Figure 1 The preparation method of low-platinum hydrogen evolution electrocatalyst based on multi-acid-carbon dot composite support includes the following steps: S1. Provide 500 mL of a carbon dot aqueous solution with a concentration of 0.12 mg / mL, and dissolve 0.2 g of silicotungstic acid in 10 mL of water to obtain a silicotungstic acid aqueous solution; continuously stir magnetically at room temperature for 30 min to obtain a multi-acid-carbon dot composite carrier solution; S2. Weigh 10 mg of acetylacetone platinum precursor and dissolve it in 10 mL of acetonitrile to obtain a platinum precursor solution. Add the platinum precursor solution dropwise to the polyacid-carbon dot composite carrier solution prepared in step S1. The platinum precursor solution should be added dropwise within 5 min. After the addition is complete, continue stirring for 12 h to obtain a mixed solution. S3. The mixed solution obtained in step S2 is evaporated and concentrated at 100°C, and then freeze-dried for 24 hours to obtain a fluffy solid precursor powder. S4. The solid precursor powder obtained in step S3 is placed in a tube furnace and heated at 5°C / min under a mixed atmosphere of 10% H2 / Ar by volume. -1 The temperature was programmed to be raised to 200°C and heat-treated at this temperature for 2 hours. After being cooled to room temperature in the furnace, the target product, a low-platinum hydrogen evolution electrocatalyst, was finally obtained. The platinum mass fraction in the low-platinum hydrogen evolution electrocatalyst is 1.67 wt%, which meets the requirement that the platinum mass fraction in the low-platinum hydrogen evolution electrocatalyst is less than 2 wt%.
[0026] Example 2 The application of the low-platinum hydrogen evolution electrocatalyst based on the multi-acid-carbon dot composite support involves uniformly coating the slurry of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 onto the surface of a glassy carbon electrode to prepare a working electrode. This working electrode is then assembled with an Ag / AgCl reference electrode and a carbon rod counter electrode to form a three-electrode system. The electrolyte is a 0.5M sulfuric acid aqueous solution.
[0027] Comparative Example Commercially available 20% Pt / C catalyst.
[0028] Test case Test Example 1 Reference Figure 2 The structure of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 was first determined by XRD pattern. As can be seen from the figure, it not only achieves the effective composite of tungstic silicic acid, carbon dots and platinum, but also ensures the retention of the key structures of each component. This provides an experimental basis for the structural rationality of the low-platinum hydrogen evolution electrocatalyst in the subsequent strong anchoring effect, high conductivity and high catalytic activity.
[0029] Test Example 2 Reference Figure 3 and Figure 4 , Figure 3 Image a is a transmission electron microscope (TEM) characterization image of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 3 Image b is a transmission electron microscope (TEM) characterization image of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 3 Image c is a high-resolution transmission electron microscope (HRTEM) characterization image of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 4 This is an EDS elemental distribution diagram of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of the present invention. Figure 3 From a and b, it can be seen that silicotungstic acid combines with carbon dots to form a multi-acid-carbon dot layer, and platinum clusters are uniformly dispersed on the multi-acid-carbon dot layer, with a platinum cluster size of ~2.63 nm; from Figure 3 HRTEM of medium c showed that platinum clusters maintained platinum (111) crystal planes with a lattice spacing of 0.224 nm. Figure 4 EDS-Mapping revealed that polyacids and carbon dots were uniformly composited, with platinum evenly dispersed on the polyacid-carbon dot layer.
[0030] Reference Figure 5 , Figure 5 In Figure a, the high-resolution Pt 4f XPS spectrum of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention is shown. Figure 5 b is the high-resolution W4f XPS spectrum of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 5 c is the high-resolution O 1s XPS spectrum of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention; Figure 5 Image d shows the high-resolution C1s XPS spectrum of the low-platinum hydrogen evolution electrocatalyst prepared in Example 1 of this invention. Figure 5 From a, we know that Pt 4f 7 / 2 (72.0 eV) and Pt 5 / 2 The two characteristic peaks at (75.3 eV) indicate that platinum is dominant, which is attributed to the presence of platinum clusters; the peaks at 73.0 eV / 76.4 eV and 76.0 eV / 79.4 eV can be attributed to Pt. 2+ and Pt 4+ This is due to the interaction between the platinum cluster and the polyacids and carbon dots, as well as the surface oxidation effect of the electrocatalyst. Figure 5 As shown in b, the peak at 36.1 eV / 38.2 eV corresponds to W from silicotungstic acid. 6 + The peaks at 34.5 eV / 36.7 eV are due to the reduction of silicotungstic acid during the synthesis process, producing W. 5+ .Depend on Figure 5 As shown in c, the O1s spectrum can be decomposed into five peaks, indicating the presence of W=O (530.6 eV), WOW (531.1 eV), and WO-Si (531.7 eV), all originating from silicotungstic acid; the peak at 532.3 eV can be attributed to the presence of Pt-O, which originates from platinum clusters bound to carbon dots and polyacids; the CO peak at 532.8 eV can be attributed to carbon dots, while the peak at 533.4 eV is attributed to water absorbed on the catalyst surface. Figure 5 As can be seen from d, C1s shows C=C, CO, and OC=O, which are characteristic peaks of CDs.
[0031] Test Example 3 Reference Figure 6 The electrocatalytic hydrogen evolution performance of the low-platinum hydrogen evolution electrocatalyst in 0.5 M H₂SO₄ solution in Example 2 was tested by linear sweep voltammetry. The hydrogen evolution overpotential of the low-platinum hydrogen evolution electrocatalyst was as low as +17 mV (relative to RHE, at 10 mA·cm⁻¹). -2 (At current density), it is far superior to the -34mV of commercial 20%Pt / C catalysts.
[0032] Reference Figure 7 At an overpotential of 100 mV, the mass activity of the low-platinum hydrogen evolution electrocatalyst in Example 2 of this invention reached as high as 4.42 A·mg. -1 Pt; simultaneously, its specific activity is 39.61 mA·cm⁻¹. -2 These results clearly demonstrate that the performance of the low-platinum hydrogen evolution electrocatalysts is significantly superior to that of the commercial 20% Pt / C catalyst (with a mass activity of only 0.05 A·mg at an overpotential of 100 mV). -1 Pt has a specific activity of only 0.48 mA·cm⁻¹ -2 ).
[0033] Reference Figure 8 In Example 2 of this invention, the low-platinum hydrogen evolution electrocatalyst exhibits negligible performance degradation after 3000 cycles at 50 mA·cm⁻¹. -2 At that time, the overpotential decay was less than 1mV, and the commercial 20% platinum-carbon ... -2 At that time, the overpotential decay exceeded 8mV.
[0034] Reference Figure 9 In Example 2 of this invention, the low-platinum hydrogen evolution electrocatalyst exhibits excellent stability (at least 100 h), while the activity of the commercial 20% platinum-carbon catalyst almost completely decays within 10 hours.
[0035] Reference Figure 10 The low-platinum hydrogen evolution electrocatalyst membrane electrode in Example 2 of this invention exhibits excellent performance at an industrial-grade current density of 1 A·cm⁻¹. -2 2A·cm -2 and 3A·cm -2 The battery operating voltages are 1.61V, 1.72V and 1.82V respectively.
[0036] Reference Figure 11 In Example 2 of this invention, the platinum hydrogen evolution electrocatalyst membrane electrode operates at 2 A·cm⁻¹. -2 It operated stably for 1200 hours at the specified current density. The voltage drop was only 25mV.
[0037] The embodiments shown in this specification are only used to illustrate the technical solutions of the present invention and are intended to help those skilled in the art understand the principles and advantages of the present invention. They do not constitute a limitation on the scope of protection of the present invention. Although the present invention has been specifically described, those skilled in the art can still make any modifications, equivalent substitutions or other reasonable variations to the implementation methods without departing from the spirit and scope of the present invention. All equivalent technical solutions resulting therefrom should be considered within the scope of protection of this patent.
Claims
1. A method for preparing a low-platinum hydrogen evolution electrocatalyst based on a multi-acid-carbon dot composite support, characterized in that, Includes the following steps: 1) Provide an aqueous solution of carbon dots and a polyacid solution, mix and stir to obtain a polyacid-carbon dot composite carrier solution; 2) Provide a platinum precursor solution and mix it with the polyacid-carbon dot composite carrier solution prepared in step 1), stir until homogeneous, and obtain a mixed solution; 3) The mixed solution obtained in step 2) is concentrated and dried to obtain solid precursor powder; 4) Under a reducing atmosphere, the solid precursor powder obtained in step 3) is heat-treated to obtain a low-platinum hydrogen evolution electrocatalyst.
2. The preparation method of the low-platinum hydrogen evolution electrocatalyst based on the multi-acid-carbon dot composite support according to claim 1, characterized in that, In step 1), the concentration of the carbon dot aqueous solution is 0.12 mg / mL; the mixing and stirring time is 0.5-12 h.
3. The preparation method of the low-platinum hydrogen evolution electrocatalyst based on the multi-acid-carbon dot composite support according to claim 1, characterized in that, In step 1), the polyacid solution is any one of Keggin type polyacid, Dawson type polyacid, or Anderson type polyacid.
4. The preparation method of the low-platinum hydrogen evolution electrocatalyst based on the multi-acid-carbon dot composite support according to claim 1, characterized in that, In step 2), the platinum precursor in the platinum precursor solution is any one of platinum acetylacetonate, chloroplatinic acid, and sodium chloroplatinate; The solvent for the platinum precursor solution is acetonitrile.
5. The method for preparing the low-platinum hydrogen evolution electrocatalyst based on the multi-acid-carbon dot composite support according to claim 1, characterized in that, In step 2), the stirring time is 0.5-12 hours.
6. The method for preparing the low-platinum hydrogen evolution electrocatalyst based on the multi-acid-carbon dot composite support according to claim 1, characterized in that, In step 4), the reducing atmosphere is a hydrogen-argon mixture with a hydrogen gas fraction of 10%; the heat treatment temperature is 150-250℃ and the heat treatment time is 2 hours.
7. A low-platinum hydrogen evolution electrocatalyst based on a multi-acid-carbon dot composite support, prepared by the method according to any one of claims 1-6, characterized in that, include: Polyacid-carbon dot composite carrier; Platinum nanoparticles loaded on the polyacid-carbon dot composite support; The platinum nanoparticles have a loading of less than 2 wt% and a size of less than 3 nm.
8. The application of a low-platinum hydrogen evolution electrocatalyst based on a multi-acid-carbon dot composite support prepared by any one of claims 1-6 in the hydrogen evolution reaction of water electrolysis.