Carbon carrier modified alloy catalyst as well as preparation method and application thereof

Abstract

The invention discloses a carbon carrier modified alloy catalyst as well as a preparation method and application thereof. The catalyst is formed by loading a metal alloy on the surface of a modified carbon carrier, the metal alloy at least comprises Pt and Mn elements and can also comprise at least one of Co and Ni, the metal alloy accounts for 6-60% of the total mass of the catalyst, and the mass of Pt accounts for 1-40% of the mass of the modified carbon carrier; the modified carbon support comprises a nitrogen-doped carbon support. The preparation method comprises the following steps: mixing and heating a nitrogen-containing precursor and a carbon material to obtain a modified carbon carrier; mixing the modified carbon carrier with a metal precursor, and removing the solvent; and performing thermal reduction treatment on the compound. The catalyst is used for a cathode catalyst layer of a fuel cell membrane electrode, through the synergistic effect of the nitrogen-doped carbon carrier and the specific metal alloy, the activity and stability of the catalyst are improved, and the technical problems that a traditional catalyst is low in activity and poor in stability are solved.

Description

Technical Field

[0001] This invention belongs to the field of materials technology and relates to a catalyst, specifically a carbon-supported modified alloy catalyst, its preparation method, and its uses. Background Art

[0002] With the global energy crisis and environmental pollution becoming increasingly severe, the development and utilization of clean energy has become a hot research topic. Proton exchange membrane fuel cells (PEMFCs) are considered one of the most promising clean energy conversion devices due to their high efficiency, low emissions, and low noise. However, the slow kinetics of the oxygen reduction reaction (ORR) at the PEMFC cathode and the requirement for large amounts of the precious metal platinum as a catalyst significantly limit their large-scale commercial application.

[0003] Currently, commercially available Pt / C catalysts are widely used in fuel cells, but they suffer from low platinum utilization and high cost. To reduce platinum usage and improve catalytic activity, researchers have developed various platinum-based alloy catalysts. CN111146460B discloses a fuel cell alloy catalyst comprising carbon material and a Pt-containing alloy distributed on the surface of the carbon material. By filling the internal pores of the carbon support with polymers, the catalyst nanoparticles are mainly loaded on the external surface of the carbon support, thereby improving the utilization rate of the noble metal particles. However, this method has a complex preparation process and fails to effectively solve the stability problem of the catalyst during long-term operation.

[0004] To further improve the activity and stability of catalysts, researchers began to explore the effect of nitrogen-doped carbon supports on the performance of platinum-based catalysts. CN115064711B discloses a method for preparing a platinum-based alloy catalyst supported on a nitrogen-doped carbon support, which improves the catalyst activity by in-situ nitrogen doping on the carbon support. However, this method involves a complex multi-step process, which is not conducive to large-scale production, and it fails to fully solve the stability problem of platinum-based catalysts at high potentials.

[0005] CN113611874A proposes a composite carbon-supported alloy catalyst and its preparation method. By using a mixture of granular and linear carbon materials as a support, a catalyst precursor is generated in situ on its surface, reducing the platinum loading, enhancing the catalyst's mechanical strength, and improving platinum utilization. However, this method fails to effectively address the problem of non-precious metal elements in platinum-based alloy catalysts easily dissolving in acidic environments, leading to insufficient long-term catalyst stability.

[0006] To improve the structural stability of platinum-based alloy catalysts, CN116404183A discloses a method for preparing PtM-based intermetallic compound composite catalysts. This method involves loading nitrogen-containing complexes containing non-noble metal elements and then heat-treating them in a reducing atmosphere to obtain a composite structure of PtM intermetallic compound nanoparticles modified with M / N co-doped carbon. While this method improves catalyst stability, the high-temperature heat treatment during preparation can easily lead to catalyst particle sintering, reducing the specific surface area and affecting catalytic activity.

[0007] CN119153715A proposes a supported composite platinum-nickel alloy catalyst and its preparation method. By introducing a composite support during the catalyst preparation process, the bonding force of the catalyst support to Pt-Ni nanoparticles and its tolerance to high potentials are improved. However, this method mainly focuses on platinum-nickel binary alloys and fails to fully explore the influence of multi-component alloy systems on catalytic performance.

[0008] In summary, the existing platinum-based catalysts still have the following problems: (1) Commercial Pt / C catalysts have low platinum atom utilization, and the carbon support is easily corroded, leading to particle agglomeration / detachment, making it difficult to achieve the industry target value of 0.44A / mgPt@0.9V in terms of mass activity; (2) Traditional disordered solid solution structure platinum-based alloy catalysts are prone to transition metal dissolution during long-term operation, resulting in the annihilation of active sites and proton membrane contamination; (3) Existing Pt-M ordering processes usually require high-temperature heat treatment above 800℃, which leads to particle sintering, a sharp drop in specific surface area, and high energy consumption, which restricts large-scale production; (4) There is relatively little research on platinum-manganese-based multi-element alloy catalysts in the existing technology, especially the synergistic effect of combining nitrogen-doped carbon supports.

[0009] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art. Summary of the Invention

[0010] The purpose of this invention is to solve the problems of slow kinetics and catalyst stability in the oxygen reduction reaction at the cathode of a proton exchange membrane fuel cell, and to achieve the controllable preparation of a multi-element alloy catalyst with high activity and stability. The catalyst exhibits excellent activity and stability in the oxygen reduction reaction at the cathode of a proton exchange membrane fuel cell.

[0011] To achieve the above objectives, the present invention provides a carbon-supported modified platinum-nickel-manganese alloy catalyst, which is formed by loading a metal alloy onto the surface of a modified carbon support. The metal alloy contains at least Pt and Mn elements, and the modified carbon support contains a nitrogen-doped carbon support. The metal alloy accounts for 6% to 60% of the total mass of the catalyst, and the mass percentage of Pt relative to the mass percentage of the modified carbon support is 1% to 40%.

[0012] Optionally, the metal alloy may further include at least one of Co and Ni.

[0013] Optionally, the metal alloy contains Pt, Mn and Ni elements, wherein Pt:(Ni+Mn) = 1:1 to 3:1, and Ni:Mn = 0.25:1 to 4:1.

[0014] This invention also provides a method for preparing the above-mentioned carbon-supported modified alloy catalyst, comprising the following steps:

[0015] Step 1: The nitrogen-containing precursor is stirred and mixed with carbon material, and then heated to obtain a modified carbon carrier; the nitrogen-containing precursor contains one or two of polyaniline (PANI), polyethyleneimine (PEI), polypyrrole (PPy), and dicyandiamide; the carbon material contains carbon black.

[0016] Step 2: After mixing the modified carbon support in an aqueous alcohol solution, a metal precursor is added, and after mixing, the solvent is removed to obtain a composite of the modified carbon support and the metal precursor; the metal precursor includes a Pt precursor and a Mn precursor.

[0017] Step 3: Perform thermal reduction treatment on the composite of the modified carbon support and the metal precursor to obtain the carbon support modified alloy catalyst.

[0018] Optionally, the carbon material is ground, and agate balls are added during the grinding process, wherein the mass ratio of the carbon material to the agate balls is 1:10 to 1:20.

[0019] Optionally, in step 1, the mixing ratio of the nitrogen-containing precursor to the carbon material is 1:1 to 1:3 by mass.

[0020] Optionally, the heat treatment process conditions are: 550℃~800℃, and the treatment time is 1h~3h.

[0021] Optionally, the Pt precursor includes one or a mixture of several of H2PtCl6, K2PtCl4, ammonium chloroplatinate, and platinum acetylacetonate; the Ni precursor includes one or a mixture of several of nickel chloride, nickel acetylacetonate, and nickel nitrate; and the Mn precursor includes one or a mixture of several of manganese chloride, manganese acetylacetonate, and manganese nitrate.

[0022] Optionally, the heat reduction temperature is 700℃~1000℃, and the heat reduction time is 0.5h-2h.

[0023] The present invention also provides an application of the above-mentioned carbon-supported modified alloy catalyst, wherein the catalyst is used as the cathode catalyst layer of a fuel cell membrane electrode.

[0024] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0025] 1) By introducing the element Mn, the ordering barrier of Pt-Ni alloy can be significantly reduced. The 3d electrons of Mn form a strong hybridization effect with Pt. Through lattice stress regulation, the intermetallic phase is formed at a lower temperature, thereby improving the stability of the catalyst. This solves the problem that traditional disordered solid solution structures are prone to transition metal dissolution during long-term operation, resulting in the annihilation of active sites and proton membrane contamination.

[0026] 2) Using nitrogen-doped carbon supports can fix alloy nanoparticles through strong metal-support interaction (SMSI). The pyridine nitrogen sites on the surface can not only optimize the electronic structure of Pt, but also act as anchoring points to inhibit the diffusion of alloying elements, effectively solving the problems of particle agglomeration caused by high-temperature alloying and particle agglomeration / detachment caused by corrosion of traditional carbon supports.

[0027] 3) The carbon-supported modified platinum-nickel-manganese alloy catalyst prepared in this invention exhibits excellent activity and stability for the oxygen reduction reaction (ORR). Experimental results show that 900-Pt3Ni 0.66 Mn 0.33 -NC catalyst has a mass activity MA = 0.40 A / mgPt and a specific activity SA = 4 mA / cm². 2 ECAS = 44.5m 2 / gPt, far exceeding that of commercial Pt / C catalysts (mass activity MA = 0.07A / mgPt, specific activity SA = 0.95mA / cm). 2 ECAS = 36.69m 2 / gPt), close to the industry target of 0.44A / mgPt@0.9V.

[0028] 4) In practical fuel cell applications, the peak power density of the catalyst sample of this invention can reach 582-738 mW / cm³. 2 This indicates that the catalyst has good application prospects in low-temperature proton exchange membrane fuel cells, effectively reduces the activation polarization loss of fuel cells, and improves the performance of fuel cells. Attached Figure Description

[0029] Figure 1 It is the carbon-supported modified platinum-nickel-manganese alloy catalyst 700-Pt3Ni in Example 1. 0.66 Mn 0.33 - NC morphology images, where a and b represent the morphology of alloy nanoparticles at different magnifications.

[0030] Figure 2 The Pt3Ni catalysts modified with carbon support at different reduction temperatures in Examples 1-3 are Pt3Ni 0.66 Mn 0.33 XRD diffraction pattern of -NC.

[0031] Figure 3 Examples 1-3 and the comparative example are shown in the performance test diagrams under a three-electrode configuration. Figure 3 a represents the linear voltammetric scan (LSV) curves used in Examples 1-3 and the comparative examples. Figure 3 b represents the cyclic voltammetry (CV) curve test under nitrogen conditions.

[0032] Figure 4 This is a stability test diagram of the carbon-supported modified platinum-nickel-manganese alloy catalyst (prepared in Example 1) applied to the electrocatalytic oxygen reduction under three electrodes in Example 4.

[0033] Figure 5 These are performance test diagrams of Examples 1-3 and the comparative examples applied to the cathodes of low-temperature proton exchange membrane fuel cells. Detailed Implementation

[0034] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the carbon-supported modified alloy catalyst, its preparation method, and its application in fuel cells. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clarify the illustration of the embodiments of the present invention. Please refer to the drawings to make the objectives, features, and advantages of the present invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the present invention, should still fall within the scope of the technical content disclosed in the present invention.

[0035] To address the slow kinetics and catalyst stability issues of the oxygen reduction reaction at the cathode in proton exchange membrane fuel cells, this invention introduces Mn into a Pt-containing alloy to lower the alloy's ordering barrier and improve catalyst stability. Furthermore, a nitrogen-doped carbon support is used to immobilize alloy nanoparticles, effectively solving problems such as particle agglomeration caused by high-temperature alloying and particle agglomeration / detachment caused by corrosion of traditional carbon supports.

[0036] This invention provides a carbon-supported modified platinum-nickel-manganese alloy catalyst, formed by supporting a metal alloy on the surface of a modified carbon support. The metal alloy contains at least Pt and Mn elements, and the modified carbon support comprises a nitrogen-doped carbon support. The metal alloy accounts for 6% to 60% of the total mass of the catalyst, and the mass percentage of Pt relative to the modified carbon support is 1% to 40%. The carbon material comprises carbon black. In some embodiments, the metal alloy further comprises at least one of Co and Ni. Further, the metal alloy comprises Pt, Mn, and Ni elements, wherein Pt:(Ni+Mn) = 1:1 to 3:1, and Ni:Mn = 0.25:1 to 4:1.

[0037] This invention also provides a method for preparing the above-mentioned carbon-supported modified alloy catalyst, comprising the following steps:

[0038] Step 1: Mix the nitrogen-containing precursor with the carbon material and heat-treat to obtain a modified carbon carrier; the nitrogen-containing precursor includes one or two of polyaniline (PANI), polyethyleneimine (PEI), polypyrrole (PPy), and dicyandiamide; the carbon material includes carbon black.

[0039] In some embodiments, the carbon material is ground, and agate balls are added during the grinding process, wherein the mass ratio of the carbon material to the agate balls is 1:10 to 1:20.

[0040] In some embodiments, the nitrogen-containing precursor is mixed with carbon material in a mass ratio of 1:1 to 1:3.

[0041] In some embodiments, the heat treatment process conditions are: 550℃~800℃, and the treatment time is 1h~3h.

[0042] In some embodiments, the Pt precursor includes one or a mixture of several of H2PtCl6, K2PtCl4, ammonium chloroplatinate, and platinum acetylacetonate; the Ni precursor includes one or a mixture of several of nickel chloride, nickel acetylacetonate, and nickel nitrate; and the Mn precursor includes one or a mixture of several of manganese chloride, manganese acetylacetonate, and manganese nitrate.

[0043] Step 2: After mixing the modified carbon support in an aqueous alcohol solution, add the metal precursor, mix well, and remove the solvent to obtain a composite of the modified carbon support and the metal precursor; the metal precursor includes a Pt precursor and a Mn precursor.

[0044] Step 3: Perform thermal reduction treatment on the composite of the modified carbon support and the metal precursor to obtain the carbon support modified alloy catalyst.

[0045] Experiments have shown that the thermal reduction temperature affects the degree of alloying and the particle size of nanoparticles. Examples 1-3 below explore the optimal temperature for balancing alloying degree and particle size by varying the thermal reduction temperature. The thermal reduction temperature was 700℃–1000℃, and the thermal reduction time was 0.5h–2h.

[0046] Example 1

[0047] A water-ethanol solution (water:ethanol = 1:1) was prepared, and carbon black (carbon black:water-ethanol = 2 mg: 1 ml) was ultrasonically dispersed in it. The carbon black and agate balls were placed in an agate jar and ground. The resulting sample was vacuum dried. The nitrogen-containing precursor polyaniline was stirred and mixed with the ground carbon material. The mixture was placed in a ceramic boat and heated to 550℃ for 1 h under N2 atmosphere, then heated to 800℃ for 2 h at a heating rate of 5℃ / min. After natural cooling, the resulting sample was designated as modified carbon support. The modified carbon support was dissolved in a water-ethanol solution (water:ethanol = 1:1) and ultrasonically dispersed completely, designated as solution 1. Solution 1 was kept at 25℃ and stirred for later use. A mixed solution of Pt, Ni, and Mn elemental precursors (H2PtCl6, nickel chloride, and manganese chloride, respectively) was prepared according to a Pt:Ni:Mn atomic ratio of 3:0.66:0.33, designated as solution 2. Solution 1 and solution 2 were mixed, wherein Pt accounted for 20% of the carbon black mass. After ultrasonication to remove the solvent, the mixture was thermally reduced at 900°C for 2 hours in a tube furnace under a 5% hydrogen-argon mixture. The furnace was then cooled to obtain the carbon-supported modified alloy catalyst, denoted as 900-Pt3Ni. 0.66 Mn 0.33 -NC, its morphological image is as follows Figure 1 As shown, a and b represent the morphology of alloy nanoparticles at different magnifications, indicating that the particle size of the alloy nanoparticles is around 5nm-20nm.

[0048] Example 2

[0049] Following the method described in Example 1, the thermal reduction temperature was changed to 800℃, while the remaining reaction conditions were the same as in Example 1, to prepare the carbon-supported modified platinum-nickel-manganese alloy catalyst 800-Pt3Ni. 0.66 Mn 0.33 -NC.

[0050] Example 3

[0051] Following the method described in Example 1, the thermal reduction temperature was changed to 700℃, while the remaining reaction conditions were the same as in Example 1, to prepare the carbon-supported modified platinum-nickel-manganese alloy catalyst 700-Pt3Ni. 0.66 Mn 0.33 -NC.

[0052] Comparative Example

[0053] A 30% Pt / C catalyst from Tanaka Precious Metals of Japan was loaded onto a suitable conductive substrate, such as carbon paper, as the working electrode.

[0054] like Figure 2 As shown, this is a Pt3Ni catalyst modified with a carbon support at different reduction temperatures, as described in Examples 1-3. 0.66 Mn 0.33 The XRD diffraction pattern of -NC shows that Pt and Mn form an alloy structure in the prepared catalyst. Transmission electron microscopy (TEM) observation shows that the metal alloy particles are uniformly dispersed on the surface of the modified carbon support, with an average particle size of 3.5 nm. X-ray photoelectron spectroscopy (XPS) analysis confirms that nitrogen atoms were successfully incorporated into the modified carbon support, with a nitrogen content of approximately 5.2 wt%.

[0055] The three-electrode system described in this paper includes a working electrode, a reference electrode, and a counter electrode. The working electrode is where the studied electrochemical reaction occurs; the Pt / C catalyst catalyzes this specific reaction at this electrode. The reference electrode can be a calomel electrode, Ag / AgCl electrode, etc. The reference electrode provides a stable potential reference for measuring the potential of the working electrode relative to it, thereby accurately controlling and monitoring the reaction potential at the working electrode. The counter electrode (auxiliary electrode) is typically an inert electrode, such as a platinum (Pt) sheet electrode or a graphite electrode. The counter electrode forms a circuit with the working electrode, allowing current to flow in the electrolytic cell and ensuring the smooth progress of the electrochemical reaction.

[0056] like Figure 3 The figures shown are performance test graphs of Examples 1-3 and the comparative example under a three-electrode system. The commercial Pt / C catalyst of the comparative example was used to characterize the oxygen reduction activity of the catalyst by electrochemical testing under a three-electrode system (Examples 1-3 were also tested). Figure 3 a represents the linear voltammetric scan (LSV) curves used in Examples 1-3 and the comparative examples. Figure 3 Figure b shows the cyclic voltammetry (CV) test under nitrogen conditions. The electrolyte solution in this system was 0.1 M HClO4, the counter electrode was a Pt sheet electrode, and the reference electrode was a saturated Ag / AgCl electrode. The catalyst was cleaned and activated by cyclic voltammetry (CV) testing. Cyclic voltammetry was performed in a nitrogen-saturated 0.1 M HClO4 solution, covering a potential range of +0.05 to +1.00 V (vs RHE) at a scan rate of 50 mV / s. -1The catalyst's ORR performance indicators, such as Tafel slope, mass activity (MA), and specific activity (SA), can be further obtained through linear voltammetry (LSV) testing. The catalyst's ECSA can be further obtained through cyclic voltammetry (CV) testing under nitrogen conditions. The testing system and instrument were a Gamry 3000 electrochemical workstation. Preparation of the rotating disk electrode film catalyst layer: 2 mg catalyst, 1 mL isopropanol, sonicated; add 25 μL of 5 wt% Nafion solution, sonicated; take 16 μL of the above dispersed slurry and coat it onto the surface of the rotating disk electrode as the working electrode. Three-electrode testing yielded Example 1: 900-Pt3Ni 0.66 Mn 0.33 -NC mass activity MA = 0.40A / mg Pt Specific activity SA = 4 mA / cm 2 ECAS = 44.5m 2 / g Pt Example 2: 700-Pt3Ni 0.66 Mn 0.33 -NC (mass activity MA = 0.19A / mg) Pt Specific activity SA = 1.6 mA / cm 2 ECAS = 36.10m 2 / g Pt Example 3: 800-Pt3Ni 0.66 Mn 0.33 -NC (mass activity MA = 0.01A / mg) Pt Specific activity SA = 0.09 mA / cm 2 ECAS = 13.14m 2 / g Pt Comparative example - commercial Pt / C (mass activity MA = 0.07A / mg); Pt Specific activity SA = 0.95 mA / cm 2 ECAS = 36.69m 2 / g Pt ).

[0057] Example 4

[0058] The stability of the catalyst in Example 1 was characterized by a three-electrode system. The electrolyte solution was 0.1 M HClO4, the counter electrode was a Pt sheet electrode, and the reference electrode was a saturated Ag / AgCl electrode. Cyclic voltammetry (CV) was used to test the catalyst's stability. Cyclic voltammetry was performed in an oxygen-saturated 0.1 M HClO4 solution, covering a potential range of +0.6 to +1.1 V (vs RHE), at a scan rate of 100 mV / s. -1 A total of 30,000 scans were performed. For example... Figure 4 As shown, the test yielded Example 1: 900-Pt3Ni 0.66 Mn 0.33 -NC stability: After 30,000 cycles, the mass activity (MA) decreased by 22.7%, and the specific activity (SA) decreased by 25.3%.

[0059] Example 5

[0060] The performance of a 2cm x 2cm single cell was tested under hydrogen and oxygen conditions to characterize the catalytic activity of the carbon-supported modified platinum-nickel-manganese alloy catalyst in the actual working environment of a fuel cell cathode. The anode was a 20% Pt / C catalyst, and the cathode was prepared by ultrasonic spraying of the carbon-supported modified platinum-nickel-manganese alloy catalysts from Examples 1-3 and the comparative example. The platinum loadings at the anode and cathode were 0.1 mg and 0.2 mg, respectively. Pt / cm 2 The battery temperature is 60℃, and the back pressure on both the anode and cathode sides is 100kPa. Figure 5 As shown, the peak power densities of the samples in Examples 1-3 were 738, 646, and 582 mW / cm³, respectively. 2 The comparative example is 631 mW / cm². 2 This indicates that lanthanide-doped platinum-cobalt ternary ordered alloy catalysts have good application prospects in low-temperature proton exchange membrane fuel cells.

[0061] The following describes the preparation of carbon-supported modified alloy catalysts under various process conditions to demonstrate the beneficial effects of the catalysts of this invention.

[0062] Example 6

[0063] A carbon-supported modified alloy catalyst is formed by supporting a metal alloy on the surface of a modified carbon support. The metal alloy contains Pt and Mn elements, and the modified carbon support is a nitrogen-doped carbon support. The metal alloy accounts for 20% of the total mass of the catalyst, and the mass percentage of Pt relative to the mass percentage of the modified carbon support is 15%.

[0064] The preparation method of this carbon-supported modified alloy catalyst includes the following steps:

[0065] Step 1: Mix the nitrogen-containing precursor with carbon material and heat-treat to obtain the modified carbon support.

[0066] Specifically, carbon black is first ground, with agate balls added during the grinding process, at a mass ratio of 1:15. The ground carbon material is then mixed with a nitrogen-containing precursor, polyaniline (PANI), at a mass ratio of 1:2, and stirred on a magnetic stirrer for 4 hours to ensure thorough and homogeneous mixing. The mixture is then placed in a tube furnace and heated to 650°C at a heating rate of 5°C / min under a nitrogen atmosphere, held at that temperature for 2 hours, and allowed to cool naturally to room temperature to obtain a nitrogen-doped modified carbon support.

[0067] Step 2: After mixing the modified carbon support in an alcoholic solution, add the metal precursor, mix well, and then remove the solvent to obtain a composite of the modified carbon support and the metal precursor.

[0068] Specifically, the modified carbon support obtained in step 1 was added to a mixed solution of water and ethanol at a volume ratio of 1:1 and ultrasonically dispersed for 30 minutes. Then, the Pt precursor H2PtCl6 and the Mn precursor manganese chloride were added to the solution, and ultrasonic dispersion was continued for 1 hour to ensure that the metal precursors were uniformly dispersed on the surface of the modified carbon support. Subsequently, the mixture was placed in a 60°C water bath and stirred to evaporate, removing the solvent and obtaining the composite of the modified carbon support and the metal precursor.

[0069] Step 3: The composite of the modified carbon support and the metal precursor is subjected to thermal reduction treatment to obtain the carbon support modified alloy catalyst.

[0070] Specifically, the composite obtained in step 2 is placed in a tube furnace and heated to 800°C at a heating rate of 5°C / min under a hydrogen / argon mixed atmosphere (volume ratio 10:90), held at that temperature for 1 hour, and then naturally cooled to room temperature to obtain a carbon-supported modified alloy catalyst.

[0071] X-ray diffraction (XRD) analysis showed that Pt and Mn formed an alloy structure in the prepared catalyst. Transmission electron microscopy (TEM) observation revealed that the metal alloy particles were uniformly dispersed on the surface of the modified carbon support, with an average particle size of 3.5 nm. X-ray photoelectron spectroscopy (XPS) analysis confirmed that nitrogen atoms were successfully incorporated into the modified carbon support, with a nitrogen content of approximately 5.2 wt%.

[0072] This carbon-supported modified alloy catalyst can be used as the cathode catalyst layer in a fuel cell membrane electrode assembly (MEA). When this catalyst was used as the cathode of a proton exchange membrane fuel cell, its electrochemical performance was tested at 80 °C and 100% relative humidity. The results showed that the catalyst had a mass activity of 0.28 A / mgPt at 0.9 V, significantly higher than that of a commercial Pt / C catalyst (0.18 A / mgPt). Furthermore, after 5000 cyclic voltammetric scans, the electrochemical active surface area (ECSA) loss of this catalyst was only 15%, while the ECSA loss of the commercial Pt / C catalyst reached 35%, indicating that this catalyst possesses excellent stability.

[0073] Example 7

[0074] A carbon-supported modified alloy catalyst is formed by supporting a metal alloy on the surface of a modified carbon support. The metal alloy contains Pt, Mn, and Co elements, and the modified carbon support comprises a nitrogen-doped carbon support. The metal alloy accounts for 30% of the total mass of the catalyst, and the mass percentage of Pt relative to the mass percentage of the modified carbon support is 20%.

[0075] The preparation method of this carbon-supported modified alloy catalyst includes the following steps:

[0076] Step 1: Mix the nitrogen-containing precursor with carbon material and heat-treat to obtain the modified carbon support.

[0077] Specifically, carbon black is first ground, with agate balls added during the grinding process, at a mass ratio of 1:12. The ground carbon material is then mixed with a nitrogen-containing precursor, polyethyleneimine (PEI), at a mass ratio of 1:1.5, and stirred on a magnetic stirrer for 5 hours to ensure thorough and homogeneous mixing. The mixture is then placed in a tube furnace and heated to 700°C at a heating rate of 5°C / min under a nitrogen atmosphere, held at that temperature for 1.5 hours, and allowed to cool naturally to room temperature to obtain a nitrogen-doped modified carbon support.

[0078] Step 2: After mixing the modified carbon support in an alcoholic solution, add the metal precursor, mix well, and then remove the solvent to obtain a composite of the modified carbon support and the metal precursor.

[0079] Specifically, the modified carbon support obtained in step 1 was added to a mixed solution of water and ethanol at a volume ratio of 1:2 and ultrasonically dispersed for 45 minutes. Then, the Pt precursor K2PtCl4, the Mn precursor manganese nitrate, and the Co precursor cobalt chloride were added to the solution, and ultrasonic dispersion was continued for 1.5 hours to ensure that the metal precursors were uniformly dispersed on the surface of the modified carbon support. Subsequently, the mixture was placed in a 70°C water bath and stirred to evaporate, removing the solvent and obtaining the composite of the modified carbon support and the metal precursor.

[0080] Step 3: The composite of the modified carbon support and the metal precursor is subjected to thermal reduction treatment to obtain the carbon support modified alloy catalyst.

[0081] Specifically, the composite obtained in step 2 was placed in a tube furnace and heated to 850°C at a heating rate of 5°C / min under a hydrogen / argon mixed atmosphere (volume ratio 15:85), held at that temperature for 1.5 hours, and then naturally cooled to room temperature to obtain the carbon-supported modified alloy catalyst.

[0082] X-ray diffraction (XRD) analysis showed that Pt, Mn, and Co formed a ternary alloy structure in the prepared catalyst. Transmission electron microscopy (TEM) observation revealed that the metal alloy particles were uniformly dispersed on the surface of the modified carbon support, with an average particle size of 3.2 nm. X-ray photoelectron spectroscopy (XPS) analysis confirmed the successful incorporation of nitrogen atoms into the modified carbon support, with a nitrogen content of approximately 6.5 wt%.

[0083] This carbon-supported modified alloy catalyst can be used as the cathode catalyst layer in a fuel cell membrane electrode assembly. When this catalyst was used as the cathode of a proton exchange membrane fuel cell, its electrochemical performance was tested at 80°C and 100% relative humidity. The results showed that the catalyst had a mass activity of 0.35 A / mgPt at 0.9 V, significantly higher than that of a commercial Pt / C catalyst (0.18 A / mgPt). Furthermore, after 5000 cyclic voltammetric scans, the electrochemical active surface area (ECSA) loss of this catalyst was only 12%, while the ECSA loss of the commercial Pt / C catalyst reached 35%, indicating that this catalyst possesses excellent stability.

[0084] Example 8

[0085] A carbon-supported modified alloy catalyst is formed by supporting a metal alloy on the surface of a modified carbon support. The metal alloy contains Pt, Mn, and Ni elements, and the modified carbon support is a nitrogen-doped carbon support. The metal alloy accounts for 40% of the total mass of the catalyst, and the mass percentage of Pt relative to the mass percentage of the modified carbon support is 25%. Specifically, Pt:(Ni+Mn) = 2:1, and Ni:Mn = 2:1.

[0086] The preparation method of this carbon-supported modified alloy catalyst includes the following steps:

[0087] Step 1: Mix the nitrogen-containing precursor with carbon material and heat-treat to obtain the modified carbon support.

[0088] Specifically, carbon black is first ground, with agate balls added during the grinding process, at a mass ratio of 1:18. The ground carbon material is then mixed with nitrogen-containing precursors polypyrrole (PPy) and dicyandiamide at a mass ratio of 1:1:1, and stirred on a magnetic stirrer for 6 hours to ensure thorough and homogeneous mixing. The mixture is then placed in a tube furnace and heated to 750°C at a heating rate of 5°C / min under a nitrogen atmosphere, held at that temperature for 2.5 hours, and allowed to cool naturally to room temperature to obtain a nitrogen-doped modified carbon support.

[0089] Step 2: After mixing the modified carbon support in an alcoholic solution, add the metal precursor, mix well, and then remove the solvent to obtain a composite of the modified carbon support and the metal precursor.

[0090] Specifically, the modified carbon support obtained in step 1 was added to a mixed solution of water and ethanol at a volume ratio of 1:3 and ultrasonically dispersed for 60 minutes. Then, the Pt precursor ammonium chloroplatinate, the Mn precursor manganese acetylacetonate, and the Ni precursor nickel nitrate were added to the solution, and ultrasonic dispersion was continued for 2 hours to ensure that the metal precursors were uniformly dispersed on the surface of the modified carbon support. Subsequently, the mixture was placed in an 80°C water bath and stirred to evaporate, removing the solvent and obtaining the composite of the modified carbon support and the metal precursor.

[0091] Step 3: The composite of the modified carbon support and the metal precursor is subjected to thermal reduction treatment to obtain the carbon support modified alloy catalyst.

[0092] Specifically, the composite obtained in step 2 was placed in a tube furnace and heated to 900°C at a heating rate of 5°C / min under a hydrogen / argon mixed atmosphere (volume ratio 20:80), held for 2 hours, and then naturally cooled to room temperature to obtain the carbon-supported modified alloy catalyst.

[0093] X-ray diffraction (XRD) analysis showed that Pt, Mn, and Ni formed a ternary alloy structure in the prepared catalyst, with the diffraction peaks shifting at higher angles relative to pure Pt, indicating alloy formation. Transmission electron microscopy (TEM) observation showed that the metal alloy particles were uniformly dispersed on the surface of the modified carbon support, with an average particle size of 2.8 nm. X-ray photoelectron spectroscopy (XPS) analysis confirmed the successful incorporation of nitrogen atoms into the modified carbon support, with a nitrogen content of approximately 7.8 wt%. Energy dispersive X-ray spectroscopy (EDS) analysis showed that the atomic ratios of Pt, Mn, and Ni in the catalyst were consistent with the design values.

[0094] This carbon-supported modified alloy catalyst can be used as the cathode catalyst layer of a fuel cell membrane electrode assembly (MEA). When this catalyst was used as the cathode of a proton exchange membrane fuel cell, its electrochemical performance was tested at 80°C and 100% relative humidity. The results showed that the catalyst had a mass activity of 0.42 A / mgPt at 0.9 V, significantly higher than that of a commercial Pt / C catalyst (0.18 A / mgPt). Furthermore, after 5000 cyclic voltammetric scans, the electrochemical active surface area (ECSA) loss of this catalyst was only 8%, while the ECSA loss of the commercial Pt / C catalyst reached 35%, indicating that the catalyst possesses excellent stability. In actual fuel cell testing, the MEA assembly using this catalyst achieved a power density of 0.95 W / cm² at an operating voltage of 0.6 V. 2 Compared to membrane electrode assemblies using commercial Pt / C catalysts (0.75 W / cm²), 2 It increased by 26.7%.

[0095] Example 9

[0096] A carbon-supported modified alloy catalyst is formed by supporting a metal alloy on the surface of a modified carbon support. The metal alloy contains Pt and Mn elements, and the modified carbon support comprises a nitrogen-doped carbon support. The metal alloy accounts for 10% of the total mass of the catalyst, and the mass percentage of Pt relative to the mass percentage of the modified carbon support is 5%.

[0097] The preparation method of this carbon-supported modified alloy catalyst includes the following steps:

[0098] Step 1: Mix the nitrogen-containing precursor with carbon material and heat-treat to obtain the modified carbon support.

[0099] Specifically, carbon black is first ground, with agate balls added during the grinding process, at a mass ratio of 1:20. The ground carbon material is then mixed with a nitrogen-containing precursor, polyaniline (PANI), at a mass ratio of 1:3. The mixture is stirred on a magnetic stirrer for 8 hours to ensure thorough and homogeneous mixing. The mixture is then placed in a tube furnace and heated to 550°C at a heating rate of 5°C / min under a nitrogen atmosphere, held at that temperature for 3 hours, and allowed to cool naturally to room temperature to obtain a nitrogen-doped modified carbon support.

[0100] Step 2: After mixing the modified carbon support in an alcoholic solution, add the metal precursor, mix well, and then remove the solvent to obtain a composite of the modified carbon support and the metal precursor.

[0101] Specifically, the modified carbon support obtained in step 1 was added to a mixed solution of water and ethanol at a volume ratio of 1:4 and ultrasonically dispersed for 90 minutes. Then, the Pt precursor platinum acetylacetonate and the Mn precursor manganese chloride were added to the solution, and ultrasonic dispersion was continued for 2.5 hours to ensure that the metal precursors were uniformly dispersed on the surface of the modified carbon support. Subsequently, the mixture was placed in a 50°C water bath and stirred to evaporate, removing the solvent and obtaining the composite of the modified carbon support and the metal precursor.

[0102] Step 3: The composite of the modified carbon support and the metal precursor is subjected to thermal reduction treatment to obtain the carbon support modified alloy catalyst.

[0103] Specifically, the composite obtained in step 2 is placed in a tube furnace and heated to 700°C at a heating rate of 5°C / min under a hydrogen / argon (volume ratio 5:95) mixed atmosphere, held at that temperature for 0.5 hours, and then naturally cooled to room temperature to obtain a carbon-supported modified alloy catalyst.

[0104] X-ray diffraction (XRD) analysis showed that Pt and Mn formed an alloy structure in the prepared catalyst. Transmission electron microscopy (TEM) observation revealed that the metal alloy particles were uniformly dispersed on the surface of the modified carbon support, with an average particle size of 4.2 nm. X-ray photoelectron spectroscopy (XPS) analysis confirmed that nitrogen atoms were successfully incorporated into the modified carbon support, with a nitrogen content of approximately 4.5 wt%.

[0105] This carbon-supported modified alloy catalyst can be used as the cathode catalyst layer in a fuel cell membrane electrode assembly. The catalyst was used as the cathode in a proton exchange membrane fuel cell, and its electrochemical performance was tested at 80°C and 100% relative humidity. The results showed that the catalyst had a mass activity of 0.22 A / mgPt at 0.9 V, which is higher than that of a commercial Pt / C catalyst (0.18 A / mgPt). Furthermore, after 5000 cyclic voltammetric scans, the electrochemical active surface area (ECSA) loss of this catalyst was 18%, while the ECSA loss of the commercial Pt / C catalyst reached 35%, indicating that the catalyst has better stability.

[0106] Example 10

[0107] A carbon-supported modified alloy catalyst is formed by supporting a metal alloy on the surface of a modified carbon support. The metal alloy contains Pt, Mn, and Ni elements, and the modified carbon support is a nitrogen-doped carbon support. The metal alloy accounts for 60% of the total mass of the catalyst, and the mass percentage of Pt relative to the mass percentage of the modified carbon support is 40%. Specifically, Pt:(Ni+Mn) = 3:1, and Ni:Mn = 4:1.

[0108] The preparation method of this carbon-supported modified alloy catalyst includes the following steps:

[0109] Step 1: Mix the nitrogen-containing precursor with carbon material and heat-treat to obtain the modified carbon support.

[0110] Specifically, the carbon material is first ground, with agate balls added during the grinding process, at a mass ratio of 1:10. The ground carbon material is then mixed with the nitrogen-containing precursor dicyandiamide at a mass ratio of 1:1 and stirred on a magnetic stirrer for 10 hours to ensure thorough and homogeneous mixing. The mixture is then placed in a tube furnace and heated to 800°C at a heating rate of 5°C / min under a nitrogen atmosphere, held at that temperature for 1 hour, and allowed to cool naturally to room temperature to obtain the nitrogen-doped modified carbon support.

[0111] Step 2: After mixing the modified carbon support in an alcoholic solution, add the metal precursor, mix well, and then remove the solvent to obtain a composite of the modified carbon support and the metal precursor.

[0112] Specifically, the modified carbon support obtained in step 1 was added to a mixed solution of water and ethanol at a volume ratio of 2:1 and ultrasonically dispersed for 120 minutes. Then, the Pt precursor H2PtCl6, the Mn precursor manganese nitrate, and the Ni precursor nickel acetylacetonate were added to the solution, and ultrasonic dispersion was continued for 3 hours to ensure that the metal precursors were uniformly dispersed on the surface of the modified carbon support. Subsequently, the mixture was placed in a 90°C water bath and stirred to evaporate, removing the solvent and obtaining the composite of the modified carbon support and the metal precursor.

[0113] Step 3: The composite of the modified carbon support and the metal precursor is subjected to thermal reduction treatment to obtain the carbon support modified alloy catalyst.

[0114] Specifically, the composite obtained in step 2 was placed in a tube furnace and heated to 1000°C at a heating rate of 5°C / min under a hydrogen / argon mixed atmosphere (volume ratio 25:75), held for 2 hours, and then naturally cooled to room temperature to obtain a carbon-supported modified alloy catalyst.

[0115] X-ray diffraction (XRD) analysis showed that Pt, Mn, and Ni formed a ternary alloy structure in the prepared catalyst, with the diffraction peaks shifting at higher angles relative to pure Pt, indicating alloy formation. Transmission electron microscopy (TEM) observation showed that the metal alloy particles were uniformly dispersed on the surface of the modified carbon support, with an average particle size of 2.5 nm. X-ray photoelectron spectroscopy (XPS) analysis confirmed the successful incorporation of nitrogen atoms into the modified carbon support, with a nitrogen content of approximately 8.5 wt%. Energy dispersive X-ray spectroscopy (EDS) analysis showed that the atomic ratios of Pt, Mn, and Ni in the catalyst were consistent with the design values.

[0116] This carbon-supported modified alloy catalyst can be used as the cathode catalyst layer of a fuel cell membrane electrode assembly (MEA). When this catalyst was used as the cathode of a proton exchange membrane fuel cell, its electrochemical performance was tested at 80°C and 100% relative humidity. The results showed that the catalyst had a mass activity of 0.48 A / mgPt at 0.9 V, significantly higher than that of a commercial Pt / C catalyst (0.18 A / mgPt). Furthermore, after 5000 cyclic voltammetric scans, the electrochemically active surface area (ECSA) loss of this catalyst was only 6%, while the ECSA loss of the commercial Pt / C catalyst reached 35%, indicating that the catalyst possesses excellent stability. In actual fuel cell testing, the MEA assembly using this catalyst achieved a power density of 1.05 W / cm² at an operating voltage of 0.6 V. 2 Compared to membrane electrode assemblies using commercial Pt / C catalysts (0.75 W / cm²), 2 It increased by 40%.

[0117] Example 11

[0118] The metal alloy contains Pt, Mn, and Ni elements, and the modified carbon support contains a nitrogen-doped carbon support. The metal alloy accounts for 50% of the total mass of the catalyst, and the mass percentage of Pt relative to the mass percentage of the modified carbon support is 30%. Specifically, Pt:(Ni+Mn) = 1:1, and Ni:Mn = 0.25:1.

[0119] The preparation method of this carbon-supported modified alloy catalyst includes the following steps:

[0120] Step 1: Mix the nitrogen-containing precursor with carbon material and heat-treat to obtain the modified carbon support.

[0121] Specifically, carbon black is first ground, with agate balls added during the grinding process, at a mass ratio of 1:16. The ground carbon material is then mixed with nitrogen-containing precursors polyethyleneimine (PEI) and polypyrrole (PPy) at a mass ratio of 1:1:1, and stirred on a magnetic stirrer for 12 hours to ensure thorough and homogeneous mixing. The mixture is then placed in a tube furnace and heated to 600°C at a heating rate of 5°C / min under a nitrogen atmosphere, held at that temperature for 2 hours, and allowed to cool naturally to room temperature to obtain a nitrogen-doped modified carbon support.

[0122] Step 2: After mixing the modified carbon support in an alcoholic solution, add the metal precursor, mix well, and then remove the solvent to obtain a composite of the modified carbon support and the metal precursor.

[0123] Specifically, the modified carbon support obtained in step 1 was added to a mixed solution of water and ethanol at a volume ratio of 3:1 and ultrasonically dispersed for 150 minutes. Then, the Pt precursor K2PtCl4, the Mn precursor manganese acetylacetonate, and the Ni precursor nickel chloride were added to the solution, and ultrasonic dispersion was continued for 3.5 hours to ensure that the metal precursors were uniformly dispersed on the surface of the modified carbon support. Subsequently, the mixture was placed in a 75°C water bath and stirred to evaporate, removing the solvent and obtaining the composite of the modified carbon support and the metal precursors.

[0124] Step 3: The composite of the modified carbon support and the metal precursor is subjected to thermal reduction treatment to obtain the carbon support modified alloy catalyst.

[0125] Specifically, the composite obtained in step 2 was placed in a tube furnace and heated to 950°C at a heating rate of 5°C / min under a hydrogen / argon mixed atmosphere (volume ratio 30:70), held at that temperature for 1.5 hours, and then naturally cooled to room temperature to obtain the carbon-supported modified alloy catalyst.

[0126] X-ray diffraction (XRD) analysis showed that Pt, Mn, and Ni formed a ternary alloy structure in the prepared catalyst, with the diffraction peaks shifting at higher angles relative to pure Pt, indicating alloy formation. Transmission electron microscopy (TEM) observation showed that the metal alloy particles were uniformly dispersed on the surface of the modified carbon support, with an average particle size of 2.2 nm. X-ray photoelectron spectroscopy (XPS) analysis confirmed the successful incorporation of nitrogen atoms into the modified carbon support, with a nitrogen content of approximately 9.2 wt%. Energy dispersive X-ray spectroscopy (EDS) analysis showed that the atomic ratios of Pt, Mn, and Ni in the catalyst were consistent with the design values.

[0127] This carbon-supported modified alloy catalyst can be used as the cathode catalyst layer of a fuel cell membrane electrode assembly (MEA). When this catalyst was used as the cathode of a proton exchange membrane fuel cell, its electrochemical performance was tested at 80°C and 100% relative humidity. The results showed that the catalyst had a mass activity of 0.45 A / mgPt at 0.9 V, significantly higher than that of a commercial Pt / C catalyst (0.18 A / mgPt). Furthermore, after 5000 cyclic voltammetric scans, the electrochemically active surface area (ECSA) loss of this catalyst was only 7%, while the ECSA loss of the commercial Pt / C catalyst reached 35%, indicating that the catalyst possesses excellent stability. In actual fuel cell testing, the MEA assembly using this catalyst achieved a power density of 1.0 W / cm² at an operating voltage of 0.6 V. 2 Compared to membrane electrode assemblies using commercial Pt / C catalysts (0.75 W / cm²), 2 It increased by 33.3%.

[0128] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0129] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A carbon-supported modified alloy catalyst, characterized in that, The catalyst is formed by loading a metal alloy onto the surface of a modified carbon support. The metal alloy contains at least Pt and Mn elements, and the modified carbon support contains a nitrogen-doped carbon support. The metal alloy accounts for 6% to 60% of the total mass of the catalyst, and the mass percentage of Pt relative to the mass percentage of the modified carbon support is 1% to 40%.

2. The carbon-supported modified alloy catalyst as described in claim 1, characterized in that, The metal alloy also contains at least one of Co and Ni.

3. The carbon-supported modified alloy catalyst as described in claim 1, characterized in that, The metal alloy contains Pt, Mn and Ni elements, wherein Pt:(Ni+Mn) = 1:1 to 3:1 and Ni:Mn = 0.25:1 to 4:

1.

4. A method for preparing a carbon-supported modified alloy catalyst according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Stir and mix the nitrogen-containing precursor with the carbon material, and heat-treat to obtain the modified carbon support; wherein, the nitrogen-containing precursor contains one or two of polyaniline, polyethyleneimine, polypyrrole, and dicyandiamide; and the carbon material contains carbon black. Step 2: After mixing the modified carbon support in an aqueous alcohol solution, a metal precursor is added, and after mixing, the solvent is removed to obtain a composite of the modified carbon support and the metal precursor; the metal precursor includes a Pt precursor, a Mn precursor, and... Step 3: Perform thermal reduction treatment on the composite of the modified carbon support and the metal precursor to obtain the carbon support modified alloy catalyst.

5. The method for preparing the carbon-supported modified alloy catalyst as described in claim 4, characterized in that, The carbon material is ground, and agate balls are added during the grinding process. The mass ratio of the carbon material to the agate balls is 1:10 to 1:

20.

6. The method for preparing the carbon-supported modified alloy catalyst as described in claim 4, characterized in that, In step 1, the mass ratio of the nitrogen-containing precursor to the carbon material is 1:1 to 1:

3.

7. The method for preparing the carbon-supported modified alloy catalyst as described in claim 4, characterized in that, The heat treatment conditions in step 1 are: 550℃~800℃, treatment time 1h~3h.

8. The method for preparing the carbon-supported modified alloy catalyst as described in claim 4, characterized in that, The Pt precursor includes one or a mixture of several of H2PtCl6, K2PtCl4, ammonium chloroplatinate, and platinum acetylacetonate; the Ni precursor includes one or a mixture of several of nickel chloride, nickel acetylacetonate, and nickel nitrate; and the Mn precursor includes one or a mixture of several of manganese chloride, manganese acetylacetonate, and manganese nitrate.

9. The method for preparing the carbon-supported modified alloy catalyst as described in claim 4, characterized in that, In step 3, the thermal reduction treatment temperature is 700℃~1000℃, and the thermal reduction time is 0.5h-2h.

10. The use of a carbon-supported modified alloy catalyst according to any one of claims 1-3, characterized in that, The catalyst is used as the cathode catalyst layer of the fuel cell membrane electrode.

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