A method for rapidly preparing platinum-based bimetallic intermetallic compounds and applications thereof
The Joule thermal shock method for preparing platinum-based bimetallic intermetallic compounds solves the problems of long preparation time and agglomeration in traditional methods, enabling rapid and efficient preparation of uniform nanoparticles and improving the electrocatalytic activity and stability of the catalyst.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANJING NORMAL UNIVERSITY
- Filing Date
- 2023-03-07
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies make it difficult to rapidly prepare platinum-based bimetallic intermetallic compounds with uniform size, and traditional methods are prone to metal particle agglomeration, affecting the activity and stability of the catalyst.
Platinum-based bimetallic intermetallic compounds were prepared by the Joule thermal shock method. Metal salt precursors and carbon black were ultrasonically mixed, followed by freeze-drying and Joule thermal shock. By controlling the thermal shock parameters such as voltage, current, time and temperature, nanoparticles uniformly loaded on the surface of carbon black were prepared.
A rapid, high-throughput preparation of platinum-based bimetallic intermetallic compounds was achieved. The particles were uniform, approximately 4 nm in size, and exhibited excellent electrocatalytic activity. This solved the problem of metal particle aggregation and improved the stability and activity of the catalyst.
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Abstract
Description
Technical Field
[0001] This invention relates to a method for rapidly preparing platinum-based bimetallic intermetallic compounds and its application, belonging to the field of intermetallic compound preparation technology. Background Technology
[0002] Fuel cells have attracted widespread attention and have broad application prospects due to their advantages such as high energy conversion efficiency, environmentally friendly byproducts, and wide range of fuels. Among them, proton exchange membrane fuel cells (PEMFCs) are often used in automobiles and portable electronic devices due to their compact structure, portability, and high energy density. However, the slow kinetics of the oxygen reduction reaction at the cathode and the high cost and low stability of the commonly used catalyst Pt seriously hinder the wider commercial application of PMFCs.
[0003] To address these issues, significant efforts have been made to develop a series of non-precious metal-based catalysts. However, the difficulty in resolving the dissolution of non-precious metals under acidic conditions greatly limits their application prospects. Furthermore, the intrinsic activity and stability of non-precious metal-based catalysts are far lower than those of platinum-based catalysts. Therefore, Pt remains the dominant choice for commercial catalysts. Thus, developing platinum-based oxygen reduction reaction catalysts with low precious metal loadings and higher activity and durability is the most important and pressing issue in the field of fuel cell technology.
[0004] Alloying platinum with transition metals is considered an effective strategy to reduce Pt usage and improve catalytic activity and stability. In particular, carbon-supported platinum-based bimetallic intermetallic compound nanoparticles are widely recognized as the most promising low-platinum-loading oxygen reduction catalysts due to their superior oxygen reduction activity and stability.
[0005] Intermetallic compounds are a special class of alloy materials with definite stoichiometry and ordered crystal structures. In platinum-based bimetallic intermetallic compound electrocatalysts, the ordered arrangement of Pt atoms and transition metal atoms enhances the interaction between the two types of atoms, significantly improving the catalytic activity and overall structural stability of the catalyst.
[0006] Traditional carbon-supported platinum-based bimetallic intermetallic catalysts are often synthesized using an impregnation followed by tube furnace thermal annealing. The metal salt precursor is impregnated onto the carbon black surface, followed by thermal annealing. The high temperature promotes the ordered arrangement of atoms, forming the intermetallic phase. However, tube furnace thermal annealing typically takes several hours with slow heating and cooling rates, inevitably leading to metal particle agglomeration during the annealing process. This results in the formation of large intermetallic compounds, and the uniformity of particle distribution and size is difficult to control. Therefore, exploring methods for the rapid preparation of sub-nanometer-scale, uniformly sized platinum-based intermetallic compounds is both challenging and significant. Summary of the Invention
[0007] To address the problems of existing technologies, the present invention aims to provide a method for rapid and high-throughput preparation of platinum-based bimetallic intermetallic compounds and its application. The obtained intermetallic compound nanoparticles are uniformly loaded on the surface of carbon black, with a uniform size of approximately 4 nm. They exhibit excellent electrocatalytic activity in the cathode oxygen reduction reaction of proton exchange membrane fuel cells, and the method effectively solves the problem of metal particle agglomeration.
[0008] To address the problems of the existing technology, the present invention adopts the following technical solution:
[0009] A method for rapidly preparing platinum-based bimetallic intermetallic compounds includes the following steps:
[0010] (1) Preparation of carbon black supported on metal salt precursor
[0011] After ultrasonically mixing the platinum salt solution, the transition metal salt solution and the inorganic auxiliary reagent, carbon black was added and ultrasonicated to obtain a metal salt precursor mixture.
[0012] (2) Preparation of platinum-based bimetallic intermetallic compounds by Joule thermal shock
[0013] The precursor mixture of metal salts was freeze-dried to obtain precursor-loaded carbon black, which was then subjected to Joule thermal shock. After the shock, the carbon black was removed, washed, and dried to obtain the final product.
[0014] As an improvement, the platinum salt mentioned in step (1) includes chloroplatinic acid, potassium chloroplatinate, sodium chloroplatinate, or platinum chloride.
[0015] As an improvement, the transition metal salt mentioned in step (1) includes manganese chloride, cobalt chloride, nickel chloride, manganese sulfate, or manganese nitrate.
[0016] As an improvement, the carbon black mentioned in step (1) includes Vulcan XC72, Ketjen Black EC300J, or Ketjen Black EC600JD.
[0017] As an improvement, the molar ratio of platinum salt to transition metal salt in the platinum salt solution and the transition metal salt solution in step (1) is 1:(0.2-5).
[0018] As an improvement, the mass ratio of platinum salt to carbon black in the platinum salt solution described in step (1) is 1:(1-18).
[0019] As an improvement, the Joule thermal shock operation in step (2) is as follows: the sample to be thermally shocked is sandwiched between two pieces of carbon paper and placed in the Joule thermal device. The shock voltage is set to 10-40V, the shock current range is 20-60A, the shock time for each shock is 2-5 seconds, and the interval between two adjacent thermal shocks is 2-10 seconds. The thermal shock cycle can be 4-16 times, and the thermal shock temperature range can reach 800-1600℃ depending on the magnitude of the shock current.
[0020] The platinum-based bimetallic intermetallic compounds prepared by the above method have uniform size, measuring 4 nm, and have numerous active sites.
[0021] The platinum-based bimetallic intermetallic compound prepared by the above method is used as a catalyst for the oxygen reduction reaction at the cathode of a proton exchange membrane fuel cell.
[0022] Beneficial effects:
[0023] Compared with existing traditional tube furnace hot annealing methods, the present invention provides a method for rapidly preparing platinum-based bimetallic intermetallic compounds and its applications, which have the following advantages:
[0024] 1. This invention is the first to propose the use of Joule thermal shock to prepare platinum-based bimetallic intermetallic compounds. The preparation method is simple and rapid, and can prepare platinum-based bimetallic intermetallic compounds in a short time with high throughput.
[0025] 2. The platinum-based bimetallic intermetallic compound prepared by the method of the present invention can be uniformly loaded on a carbon black substrate, with a uniform size of about 4 nm, more active sites, and a stable structure. It exhibits excellent electrocatalytic activity for the cathode oxygen reduction reaction of proton exchange membrane fuel cells and has a very broad prospect for energy applications. Attached Figure Description
[0026] Figure 1 This is a high-resolution transmission electron microscope (HRTEM) image of carbon-supported Pt3Mn intermetallic compound nanoparticles prepared in Example 1 of the present invention.
[0027] Figure 2 The X-ray diffraction (XRD) pattern of carbon-supported Pt3Mn intermetallic compound nanoparticles prepared in Example 1 of this invention;
[0028] Figure 3 Carbon-supported Pt3Mn intermetallic compound nanoparticles prepared in Example 1 of this invention were subjected to nitrogen-saturated 0.1 mol / L... -1 Cyclic voltammetry (CV) curves in HClO4;
[0029] Figure 4The oxygen electrocatalytic reduction performance of carbon-supported Pt3Mn intermetallic compound nanoparticles prepared in Example 1 of this invention in HClO4. Detailed Implementation
[0030] The technical solution of the present invention will be further described in detail below through specific embodiments. However, it should be noted that the following embodiments are only used to describe the content of the invention and do not constitute a limitation on the scope of protection of the present invention.
[0031] Example 1
[0032] Add 1.5 ml of 0.05 mol / L solution -1 0.5 ml of 0.05 mol / L chloroplatinic acid solution -1 Manganese chloride solution and 3.5 ml of 0.05 mol / L -1 Sodium citrate solution was ultrasonically mixed until homogeneous. 0.06 g of Vulcan XC72 was added, and ultrasonication was continued until homogeneous to obtain a final mixture. The resulting mixture was then freeze-dried. An appropriate amount of dried carbon black was placed between two sheets of carbon paper in a Joule heating apparatus. The impact voltage was set to 20 V, the impact current to 40 A, the impact time for each impact to be 2 seconds, the interval between two adjacent thermal impacts to be 4 seconds, and the thermal shock cycle to be 12 times. Under these conditions, the thermal shock temperature was 1100 °C. After the thermal shock, the sample was removed, washed, and dried to obtain carbon-supported Pt3Mn intermetallic compound nanoparticles.
[0033] Example 2
[0034] The difference from Example 1 is that chloroplatinic acid is replaced with potassium chloroplatinate, and the rest is the same as Example 1.
[0035] Example 3
[0036] The difference from Example 1 is that chloroplatinic acid is replaced with sodium chloroplatinate, and the rest is the same as Example 1.
[0037] Example 4
[0038] The difference from Example 1 is that chloroplatinic acid is replaced with platinum chloride, and the rest is the same as Example 1.
[0039] Example 5
[0040] The difference from Example 1 is that manganese chloride is replaced with cobalt chloride, and the corresponding product is Pt3Co. The rest is the same as in Example 1.
[0041] Example 6
[0042] The difference from Example 1 is that manganese chloride is replaced with nickel chloride, and the corresponding product is Pt3Ni. The rest is the same as in Example 1.
[0043] Example 7
[0044] The difference from Example 1 is that manganese chloride is replaced with manganese sulfate, and the rest is the same as Example 1.
[0045] Example 8
[0046] The difference from Example 1 is that manganese chloride is replaced with manganese nitrate, and the rest is the same as Example 1.
[0047] Example 9
[0048] The difference from Example 1 is that the Vulcan XC72 is replaced with Ketjen Black EC300J, and the rest is the same as Example 1.
[0049] Example 10
[0050] The difference from Example 1 is that the Vulcan XC72 is replaced with Ketjen Black EC600JD, and the rest is the same as Example 1.
[0051] Example 11
[0052] The difference from Example 1 is that the sodium citrate solution is replaced with potassium citrate solution, and the rest is the same as in Example 1.
[0053] Example 12
[0054] The difference from Example 1 is that 0.5 ml of 0.05 mol / L solution was used. -1 Replace manganese chloride with 0.3 ml of 0.05 mol / L solution. -1 Manganese chloride, the rest of the contents are the same as in Example 1.
[0055] Example 13
[0056] The difference from Example 1 is that 0.5 ml of 0.05 mol / L solution was used. -1 Replace manganese chloride with 7.5 ml of 0.05 mol / L solution. -1 Manganese chloride, the corresponding product is PtMn3, and the rest is the same as in Example 1.
[0057] Example 14
[0058] The difference from Example 1 is that 0.06g VulcanXC72 is replaced with 0.04g VulcanXC72, and the rest is the same as Example 1.
[0059] Example 15
[0060] The difference from Example 1 is that 0.06g VulcanXC72 is replaced with 0.54g VulcanXC72, and the rest is the same as Example 1.
[0061] Example 16
[0062] The difference from Example 1 is that the impact voltage of 20V and the impact current of 40A are replaced with an impact voltage of 10V and an impact current of 20A. Under this condition, the thermal shock temperature is 800℃. All other contents are the same as in Example 1.
[0063] Example 17
[0064] The difference from Example 1 is that the impact voltage of 20V and the impact current of 40A are replaced with an impact voltage of 40V and an impact current of 60A. Under this condition, the thermal shock temperature is 1600℃. All other contents are the same as in Example 1.
[0065] Example 18
[0066] The difference from Example 1 is that the impact time of 2 seconds and the interval time of 4 seconds are replaced with an impact time of 5 seconds and an interval time of 10 seconds. The rest is the same as Example 1.
[0067] Example 19
[0068] The difference from Example 1 is that the thermal shock cycle of 12 times is replaced with 4 times, and the rest is the same as Example 1.
[0069] Example 20
[0070] The difference from Example 1 is that the thermal shock cycle is changed from 12 cycles to 16 cycles, while the rest is the same as Example 1.
[0071] Performance testing
[0072] (1) The carbon-supported Pt3Mn intermetallic compound nanoparticles prepared in Example 1 were physically characterized using high-resolution transmission electron microscopy (HRTEM), and the results are as follows: Figure 1 As shown.
[0073] Depend on Figure 1 It can be seen that the Pt3Mn intermetallic compound nanoparticles prepared by the method of the present invention have a diameter of about 4 nm and are uniformly distributed on the carbon black support. The small particle size provides abundant active sites and improves catalytic performance.
[0074] (2) X-ray diffraction (XRD) was performed on the carbon-supported Pt3Mn intermetallic compound nanoparticles prepared in Example 1, and the XRD patterns were obtained as follows: Figure 2 As shown.
[0075] Depend on Figure 2It can be seen that the diffraction peak positions of the Pt3Mn intermetallic compound nanoparticles completely coincide with those of the Pt3Mn intermetallic compound standard card (PDF#04-002-1993), proving the formation of the intermetallic phase.
[0076] (3) Commercially available Pt / C (Johnson Matthey, USA) was used as a reference catalyst, and the catalysts were tested under nitrogen and oxygen saturation at 0.1 mol / L. -1 Cyclic voltammetry (CV) tests were performed on the carbon-supported Pt3Mn intermetallic compound nanoparticles prepared in Example 1 and commercial Pt / C in HClO4. The tests were conducted on a CHI 760E electrochemical workstation using a three-electrode system. The test voltage range was -0.2V to 1.2V, and the scan rate was 50mV / s. All measurement potentials were converted to reversible hydrogen electrodes.
[0077] Depend on Figure 3 It can be seen that the prepared Pt3Mn intermetallic compound electrocatalyst exhibits a stronger current intensity and a stronger response signal to oxygen compared to commercial Pt / C.
[0078] (4) Commercially available Pt / C (Johnson Matthey, USA) was used as a reference catalyst in an oxygen-saturated atmosphere of 0.1 mol L⁻¹. -1 Linear sweep voltammetry (LSV) tests were performed on the carbon-supported Pt3Mn intermetallic compound nanoparticles prepared in Example 1 and commercial Pt / C in HClO4. The tests were conducted on a CHI760E electrochemical workstation using a three-electrode system. The test voltage range was -0.2V to 0.9V, and the scan rate was 5mV / s. All measurement potentials were converted to reversible hydrogen electrodes.
[0079] Depend on Figure 4 It can be seen that the half-wave potential of the prepared Pt3Mn intermetallic compound catalyst is 0.90V, which is greater than that of commercial Pt / C (0.85V), and it exhibits superior ORR performance.
[0080] In summary, this invention is the first to propose the use of Joule thermal shock to prepare platinum-based bimetallic intermetallic compounds. The preparation method is simple and rapid, and can prepare platinum-based bimetallic intermetallic compounds in a short time with high throughput. The obtained intermetallic compound nanoparticles are uniformly loaded on the carbon black surface, with a uniform size of about 4 nm. They exhibit excellent electrocatalytic activity for the cathode oxygen reduction reaction of proton exchange membrane fuel cells, and this method effectively solves the problem of metal particle agglomeration.
[0081] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any simple changes or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention shall fall within the scope of protection of the present invention.
Claims
1. A method for rapidly preparing platinum-based bimetallic intermetallic compounds, characterized in that, Includes the following steps: (1) Preparation of carbon black supported on metal salt precursor After ultrasonically mixing a platinum salt solution with a transition metal salt solution and an auxiliary reagent, carbon black is added, and the mixture is ultrasonically mixed to obtain a metal salt precursor mixture. The molar ratio of platinum salt to transition metal salt in the platinum salt solution and the transition metal salt solution is 1:(0.2~5); the mass ratio of platinum salt to carbon black in the platinum salt solution is 1:(1~18); the auxiliary reagent is sodium citrate or potassium citrate; the transition metal salt includes manganese chloride, cobalt chloride, nickel chloride, manganese sulfate, or manganese nitrate. (2) Preparation of platinum-based bimetallic intermetallic compounds by Joule thermal shock The precursor mixture of metal salts was freeze-dried to obtain precursor-loaded carbon black, which was then subjected to Joule thermal shock. After the shock, the sample was removed, washed, and dried to obtain the final product. The Joule thermal shock procedure was as follows: the sample to be thermally shocked was sandwiched between two pieces of carbon paper and placed in a Joule thermal apparatus. The shock voltage was set to 10-40 V, the shock current range was 20-60 A, the shock duration was 2-5 seconds, the interval between two consecutive thermal shocks was 2-10 seconds, the thermal shock cycle was 4-16 times, and the thermal shock temperature range was 800-1600 °C depending on the magnitude of the shock current.
2. The method for rapidly preparing platinum-based bimetallic intermetallic compounds according to claim 1, characterized in that: The platinum salts mentioned in step (1) include chloroplatinic acid, potassium chloroplatinate, sodium chloroplatinate, or platinum chloride.
3. The method for rapidly preparing platinum-based bimetallic intermetallic compounds according to claim 1, characterized in that: The carbon black mentioned in step (1) includes Vulcan XC72, Ketjen Black EC300J or Ketjen Black EC600JD.
4. The platinum-based bimetallic intermetallic compound prepared according to the method of claim 1, characterized in that, The platinum-based bimetallic intermetallic compound has a uniform size of 4 nm.
5. The application of the platinum-based bimetallic intermetallic compound prepared by the method according to claim 1 as a catalyst for the oxygen reduction reaction at the cathode of a proton exchange membrane fuel cell.