WO2023109510A1 - 一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用 - Google Patents

一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用 Download PDF

Info

Publication number
WO2023109510A1
WO2023109510A1 PCT/CN2022/135189 CN2022135189W WO2023109510A1 WO 2023109510 A1 WO2023109510 A1 WO 2023109510A1 CN 2022135189 W CN2022135189 W CN 2022135189W WO 2023109510 A1 WO2023109510 A1 WO 2023109510A1
Authority
WO
WIPO (PCT)
Prior art keywords
iridium
catalyst
platinum
highly dispersed
small amount
Prior art date
Application number
PCT/CN2022/135189
Other languages
English (en)
French (fr)
Inventor
廖世军
张笑容
Original Assignee
华南理工大学
广州现代产业技术研究院
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华南理工大学, 广州现代产业技术研究院 filed Critical 华南理工大学
Publication of WO2023109510A1 publication Critical patent/WO2023109510A1/zh

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/88—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material
    • H01M4/92—Metals of platinum group
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the invention belongs to the technical field of new energy proton exchange membrane fuel cells, and relates to a fuel cell carbon-supported platinum-based anti-reversal catalyst with a small amount of highly dispersed iridium surface-modified and its preparation method and application.
  • Proton exchange membrane fuel cell has important advantages such as high energy conversion efficiency, zero emission, and fast start-up speed, and has broad application prospects in the fields of transportation, communication, aviation/aerospace, and underwater submarines.
  • cost and durability are the two main technical barriers to the commercialization of PEMFCs.
  • durability refers to the ability of a material or product to resist long-term damage from both itself and the objective environment.
  • the operating conditions of the fuel cell are important factors affecting its durability. The operating conditions that affect the durability include start-stop, icing/melting, high potential, and variable load and dry/wet cycles etc.
  • Optimizing the system control strategy is an effective method commonly used in the development of fuel cell vehicles to avoid the phenomenon of reverse polarity, but the more popular and recognized method is to develop catalysts with anti-polarity performance.
  • the active ingredient of the widely used anti-reversal catalyst is mainly iridium or iridium oxide. Once the reverse polarity occurs, the iridium catalyst can make the decomposition reaction of water molecules proceed preferentially and precipitate oxygen and hydrogen, thereby inhibiting the carbon oxidation reaction. , The effect of protecting the carbon carrier from being oxidized.
  • the current anti-reversal technology is mainly to add a catalyst substance containing iridium to the platinum-carbon catalyst layer, or to directly prepare and use a carbon-supported platinum-based catalyst containing iridium.
  • the amount of iridium is usually as high as one-third to five times that of platinum. One, it increases the manufacturing cost of the fuel cell.
  • Chinese patent application CN113178582A discloses a proton exchange membrane fuel cell anti-anti-electrode anode catalyst
  • the anti-anti-electrode anode catalyst is a platinum-iridium alloy supported by carbon nanotubes, and the anode catalytic layer does not need to add additional anti-anti-electrode additives , to avoid the agglomeration caused by the direct addition of iridium or iridium oxide.
  • the molar ratio of platinum to iridium in the anti-reverse catalyst provided by the invention is 6 ⁇ 1:1, the amount of iridium is large, and the utilization rate of iridium is not high, resulting in that the membrane electrode prepared by using this catalyst does not have a significantly enhanced reaction. Extremely resistant properties.
  • Chinese patent application CN112838224A discloses a proton exchange membrane fuel cell membrane electrode anti-reversal additive and its preparation method.
  • the additive includes a self-supporting iridium-cobalt alloy catalyst prepared by sodium borohydride reduction, and the anode is introduced into the
  • the anti-reverse additive can effectively improve the anti-reverse performance of the membrane electrode, and can effectively alleviate the carbon corrosion of the anode catalytic layer and the agglomeration of platinum particles caused by the reverse electrode.
  • the particle size of the additive described in this invention is as high as 100nm, and the loading capacity of the additive in the anode catalytic layer is relatively large, while consuming more iridium, the thickness of the catalytic layer will be significantly increased, resulting in the mass transfer of the membrane electrode under the high current density. Impedance increases.
  • Chinese patent application CN111082078A discloses a method for preparing a membrane electrode assembly with high performance and anti-voltage resistance.
  • the membrane electrode is prepared by adding electrolytic water catalyst materials such as iridium, ruthenium or oxide during the preparation of the anode, and the anode is introduced into the catalyst. After the material, it can effectively slow down the damage of the reverse electrode to the performance of the membrane electrode caused by the lack of air.
  • the voltage-resistant counter-electrode membrane electrode described in this invention is obtained by adding electrolytic water catalytic materials to the anode.
  • the catalytic materials are difficult to disperse evenly when preparing the anode slurry, and the conductivity of metal oxides is relatively poor, resulting in metals such as iridium and ruthenium or
  • the effective utilization rate of metal oxides is greatly reduced, and the anti-tolerance of membrane electrodes is low, which leads to an increase in the amount of metals such as iridium and ruthenium and an increase in cost.
  • directly adding metals or metal oxides to the catalytic layer will cause metal particles agglomeration, leading to a decrease in the catalytic activity of electrolyzed water.
  • Iridium is a precious metal element with very few resources, and its price is very expensive. In addition to being limited by resources, the use of a large amount of iridium in fuel cell membrane electrodes will greatly increase the cost of fuel cells and hinder the large-scale development of fuel cells. scale commercialization process.
  • the anti-reverse performance of the fuel cell membrane electrode is of great significance to ensure the durability and stability of the fuel cell.
  • the widely used anti-reverse method is to add a carbon-supported platinum-based anti-reverse electrode containing metal iridium to the catalyst layer.
  • Catalysts generally have the problem of using a large amount of iridium metal, which leads to an increase in the cost of the fuel cell, and the anti-reverse effect is mediocre.
  • the present invention proposes a carbon-supported platinum-based anti-electrode catalyst that uses a small amount of highly dispersed iridium surface-modified carbon-supported platinum-based catalysts.
  • the method of anti-electrode catalyst, the prepared catalyst has important advantages such as good anti-electrode anti-effect, low usage of iridium and the like.
  • Using the carbon-supported platinum-based anti-reverse pole catalyst of the invention can effectively reduce the cost of the fuel cell while ensuring the durability and stability of the fuel cell.
  • the invention also solves the problems of particle agglomeration and poor electrical conductivity of the anti-counter-electrode catalytic material directly added to the catalytic layer.
  • the invention solves an important problem faced by the commercialization of the fuel cell, and has great significance for promoting the large-scale commercialization of the fuel cell.
  • the present invention aims to provide a method for preparing a fuel cell carbon-supported platinum-based anti-reversal catalyst with a small amount of highly dispersed iridium surface modification.
  • the catalyst When the catalyst is applied to a membrane electrode, it can significantly improve the anti-reversal performance of the fuel cell and reduce the amount of iridium .
  • the invention discloses a method for preparing a fuel cell carbon-supported platinum-based anti-reversal catalyst modified on the surface of a small amount of highly dispersed iridium.
  • the iridium atom is highly dispersed on the surface of the carbon-supported platinum-based catalyst by impregnating an iridium complex in an organic solvent.
  • Described preparation method comprises the steps:
  • Step 1 Take a small amount of metallic iridium precursor, dissolve it, add a complexing agent, and stir evenly at room temperature to obtain an iridium complex solution;
  • Step 2 Weigh an appropriate amount of carbon-supported platinum-based catalyst, wet it with a small amount of deionized water, add the solvent stirred uniformly in step 1, and sonicate for 30 minutes;
  • Step 3 transfer the homogeneously mixed solution in step 2 to a constant temperature water bath, and evaporate the solvent to dryness;
  • Step 4 Transfer the catalyst after the solvent is evaporated to dryness in step 3 to a quartz boat, place it in a tube furnace, and perform reduction heat treatment under a specific atmosphere to prepare a small amount of highly dispersed iridium surface-modified carbon-supported platinum-based catalyst.
  • the content of the highly dispersed iridium supported on the surface of the catalyst by modification is 0.1%-5wt%.
  • the precursor includes one or two of iridium trichloride hydrate, chloroiridic acid, ammonium hexachloroiridate, and potassium chloroiridite.
  • the complexing agent includes one or both of citric acid, tartaric acid, salicylic acid, and EDTA, and the ratio of the complexing agent to iridium is 1:1-3:1 (molar ratio ).
  • the solvent used for the iridium complex includes pure water and a mixed solvent of water, alcohol, and ketone;
  • the alcohols used include one of methanol, ethanol, ethylene glycol, and isopropanol. More than one species, the volume ratio of water and alcohol is 1:1-1:5. All ketones including acetone, cyclohexanone, etc.;
  • the carbon-supported platinum-based catalyst includes a carbon-supported platinum catalyst, and an alloy catalyst formed of carbon-supported Pt and Ru, Fe, Ni, Co, Au or Pd, and the platinum or platinum alloy content in the catalyst is 20%-60%.
  • the constant temperature water bath temperature described in step 3 is controlled at 50-80°C.
  • the specific atmosphere described in step 4 includes one of hydrogen atmosphere, hydrogen-argon mixed gas atmosphere, hydrogen-nitrogen mixed gas atmosphere, and air atmosphere.
  • the temperature of the reduction heat treatment in step 4 is 100-800° C., and the heat treatment time is 0.5-5 hours.
  • the forms of highly dispersed iridium include: single-atom dispersion, atomic cluster dispersion and sub-nanometer dispersion.
  • a small amount of highly dispersed iridium surface-modified fuel cell carbon-supported platinum-based anti-reverse catalyst the content of the highly dispersed iridium loaded on the surface of the catalyst is 0.1-5 wt%;
  • the highly dispersed iridium Forms include: single-atom dispersion, atomic cluster dispersion and sub-nanometer dispersion.
  • a small amount of highly dispersed iridium surface-modified carbon-supported platinum-based catalyst is used as a cathode and an anode catalyst in a fuel cell to prepare a membrane electrode with excellent anti-reversal performance.
  • the anti-reversal evaluation method of the fuel cell catalyst prepared by the present invention is as follows: a small amount of highly dispersed iridium-surface-modified platinum-carbon catalyst is used as the anode and cathode catalyst of the membrane electrode, and an external circuit is used to apply a constant current of 0.2A/cm to the single cell.
  • the anti-reversal characteristics of the catalyst were evaluated by testing the reverse polarity time of the membrane electrode and the performance change of the single cell before and after the reverse polarity.
  • the present invention focuses on the structure of the fuel cell carbon-supported platinum-based anti-reversal catalyst, and aims to use a small amount of highly dispersed iridium to modify the surface of the carbon-supported platinum-based catalyst, and use a small amount of iridium to effectively improve the anti-reversal performance of the membrane electrode. Greatly improve the utilization rate of iridium.
  • the present invention has the advantage that:
  • Iridium exists on commercial platinum-carbon catalysts in a highly dispersed form, which greatly improves the utilization rate of iridium, can greatly reduce the amount of iridium used, and effectively reduces the anti-reversal cost of fuel cells.
  • Iridium complex organic solvent impregnation technology ensures a high degree of dispersion of iridium on the surface of carbon-supported platinum-based catalysts.
  • Figure 1 is a schematic diagram of a small amount of highly dispersed iridium surface-modified fuel cell carbon-supported platinum-based catalyst
  • Fig. 2 is the X-ray diffraction figure of embodiment 1, embodiment 2 and comparative example catalyst;
  • Fig. 3 is the comparison diagram of the oxygen evolution (OER) activity of the catalyst of embodiment 1, embodiment 2 and comparative example;
  • Figure 4 is a comparative diagram of the oxygen reduction (ORR) activity of the catalysts of Example 1, Example 2 and Comparative Example;
  • Fig. 5 is the comparison diagram of the reverse polarity time of catalyst of embodiment 1, embodiment 2 and comparative example
  • Figure 6 is a performance comparison diagram before and after the membrane electrode counter electrode prepared by the catalyst of Example 1;
  • Figure 7 is a performance comparison diagram before and after the membrane electrode counter electrode prepared by the catalyst of Example 2;
  • Figure 8 is a performance comparison diagram before and after the membrane electrode counter electrode prepared by the catalyst of the comparative example
  • Fig. 9 is a comparison chart of the voltage decay of the membrane electrodes prepared by the catalysts of Examples 1 and 2 and the comparative example before and after the reverse electrode at a current density of 0.8A/cm2.
  • Step 1 Dissolve 2 mg of iridium trichloride hydrate (54% iridium content) in a mixed solution of 1 ml of water and ethanol, the volume ratio of water and alcohol is 1:5, add lemon acid, the molar ratio of citric acid to iridium is 2:1, stir well at room temperature;
  • Step 2 Weigh 200mg of JM9100 (60%Pt/C) catalyst, add a small amount of deionized water to wet it, mix it with the solution obtained in step 1, and sonicate for 30 minutes;
  • Step 3 transfer the mixed solution to a constant temperature water bath at 50°C, and evaporate the solvent to dryness;
  • Step 4 Transfer the catalyst obtained in step 3 to a quartz boat, place it in a tube furnace, and heat-treat it in a hydrogen-argon gas mixture atmosphere.
  • % Pt/Ir mass ratio ⁇ 110:1) carbon-supported platinum-based catalyst.
  • the above-mentioned membrane electrode was assembled into a fuel cell, and the battery performance and anti-reversal test were carried out.
  • the conditions of the battery performance test were as follows: the anode fuel was hydrogen, the cathode oxidant was air, the battery temperature was 80°C, and the relative humidity of the anode and cathode was 100%.
  • the cathode and anode back pressure is 200kPa.
  • the anti-reverse test conditions are as follows: battery temperature 80°C, cathode and anode relative humidity 100%, cathode and anode backpressure 0, anode intake air is high-purity hydrogen, cathode air, external constant current source, guaranteed current 0.2A/ cm 2 (the anode is connected to the positive electrode of the constant current source).
  • Step 1 Dissolve iridium trichloride hydrate with a mass of 0.74 mg in a mixed solution of 1 ml of water and methanol.
  • the volume ratio of water and methanol is 1:2, and add salicylic acid Acid, the molar ratio of salicylic acid and iridium in the mixed solution is 3:1, stir evenly at room temperature;
  • Step 2 Weigh 200 mg of JM9100 catalyst, wet it with deionized water, mix it with the solution obtained in Step 1, and ultrasonicate for 30 minutes;
  • Step 3 transfer the mixed solution to a constant temperature water bath at 80°C, and evaporate the solvent to dryness;
  • Step 4 Transfer the catalyst obtained in step 3 to a quartz boat, place it in a tube furnace, and roast it in an air atmosphere.
  • the roasting temperature is 200° C.
  • the heat treatment time is 2 hours.
  • the iridium content is 0.20% (Pt /Ir mass ratio ⁇ 300:1) carbon-supported platinum-based catalyst.
  • Example 1 The above catalysts are used to prepare membrane electrodes, and the methods for performing fuel cell performance and anti-reversal tests are the same as in Example 1.
  • the difference from Example 1 is that the catalysts used in the cathode and anode catalyst layers of the anti-reverse electrode membrane electrode are all commercial JM9100 catalysts that have not been impregnated with iridium complexes.
  • Figure 1 is a schematic diagram of a small amount of highly dispersed iridium surface-modified carbon-supported platinum-based anti-reversal catalyst prepared by the present invention.
  • Fig. 2 is the XRD pattern of the catalysts of Examples 1, 2 and Comparative Example, it can be seen that only the particle size of the catalyst changes after the iridium complex organic solvent impregnation treatment.
  • Figure 3 and Figure 4 are the LSV test charts of the catalysts of Examples 1, 2 and Comparative Example. It can be seen that after the carbon-supported platinum-based catalyst is impregnated with an iridium complex organic solvent, the ORR activity and conductivity of the catalyst have not changed significantly. , the OER activity was significantly enhanced.
  • Fig. 5 is the reverse polarity time curve that embodiment 1, 2 and comparative example catalyst carry out anti-polarity reverse test, can see that after a small amount of highly dispersed iridium surface is modified, the anti-polar reverse time of embodiment 1 and 2 is respectively that of comparative example 3.38 times and 2 times.
  • Fig. 6, Fig. 7 and Fig. 8 are respectively embodiment 1, 2 and the fuel cell polarization curve before and after the comparative example catalyst reversed pole
  • Fig. 9 is the voltage attenuation contrast chart before and after above-mentioned several catalysts reversed pole, before the reversed pole test.
  • the activity and conductivity of the catalyst were not affected due to the highly dispersed iridium on the surface of the catalyst.
  • the voltage decay of the comparative example was as high as 124mV, while the voltage decay of Examples 1 and 2 was only 40mV and 45mV.
  • the carbon-supported platinum-based anti-reversal catalyst provided by the present invention can effectively improve the reversal tolerance of the fuel cell.
  • the impregnated catalyst has significantly enhanced OER activity, and it is used as the active component of the catalytic layer to prepare a membrane electrode with excellent anti-reverse performance.
  • the performance test and anti-reverse test show that , the membrane electrode reversal tolerance of the catalytic layer using the catalyst is significantly improved.
  • the OER activity of the catalyst after the impregnation treatment is significantly enhanced. Because sufficient iridium is highly dispersed on the surface of the catalyst, the membrane electrode with the active component of the catalyst seat has excellent anti-reverse performance, and the water electrolysis time is long. increase in magnitude.
  • the catalyst since iridium is highly dispersed on the surface of the catalyst, the catalyst has a significantly enhanced OER activity, and the membrane electrode prepared with the catalyst as an active component has excellent reversal tolerance, and the initial anti-reversal time substantial improvement.
  • the catalyst after the iridium complex impregnation heat treatment has almost unchanged ORR activity and significantly enhanced OER activity, and it is used as the active component of the catalytic layer, and the prepared membrane electrode has significantly enhanced Reversal tolerance.
  • the membrane electrode prepared with this catalyst has excellent anti-reversal performance, and the water electrolysis time of the fuel cell is effectively prolonged.
  • Embodiment 8 is a diagrammatic representation of Embodiment 8

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Materials Engineering (AREA)
  • Inert Electrodes (AREA)
  • Catalysts (AREA)

Abstract

本发明公开了一种少量高度分散铱表面修饰的燃料电池铂基抗反极催化剂及其制备方法与应用。该方法为：采用铱络合物有机溶剂浸渍铂基催化剂，然后通过在特定气氛下热处理，使铱原子在铂基催化剂表面高度分散；将铱前驱体溶解到水和醇的混合溶液中，加入络合剂，室温下搅拌均匀；称取铂基催化剂，用去离子水润湿，与步骤一所得溶液混合，超声；将上述混合物转移到恒温水浴槽中，蒸干溶剂；将蒸干溶剂后的物料转移到石英舟，置于管式炉中，在特定气氛下还原热处理，制得表面修饰有少量高度分散铱的铂基催化剂。本发明既解决了燃料电池的抗反极难题，又大幅度降低了贵金属铱的用量，对于促进燃料电池大规模商业化具有重要意义。

Description

一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用 技术领域
本发明属于新能源质子交换膜燃料电池技术领域，涉及一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用。
 背景技术
质子交换膜燃料电池（PEMFC）具有能量转换效率高、零排放、启动速度快等重要优点，在交通运输、通讯、航空/航天以及水下潜艇等领域具有广阔的应用前景。目前，成本和耐久性是PEMFC商用化的两大主要技术壁垒。其中，耐久性表示材料或产品抵抗自身和客观环境双重因素长期破坏作用的能力。通常，除了材料本身的老化、失活等因素外，燃料电池的运行工况是影响其耐久性的重要因素, 影响耐久性的工况有启停、结冰/融冰，高电位，变载和干/湿循环等。启停、变载工况和外部环境造成质子交换膜燃料电池阳极燃料气欠气时，膜电极上常常会出现水电解和碳腐蚀同时进行的反应，且这些反应成为电子和质子的来源，即电极的反极现象。膜电极的反极会带来严重的问题，碳载体的腐蚀会导致铂纳米颗粒的快速长大和催化剂的活性快速下降，同时，反极过程会产生大量的热量，引起质子膜的穿孔并进而引发膜电极短路，最终导致灾难性的电池故障。优化系统控制策略是燃料电池汽车开发常用的避免反极现象发生的有效方法，但是目前更通行和获得更高的认可的方法是开发具有抗反极性能的催化剂。目前广泛使用的抗反极催化剂的活性成分主要是铱或者铱的氧化物，一旦出现反极现象时，铱催化剂可以使得水分子的分解反应优先进行而析出氧气和氢气，从而达到抑制碳氧化反应、保护碳载体不会被氧化的效果。
目前的抗反极技术主要是在铂碳催化剂层中添加含有铱的催化剂物质，或者直接制备和使用含有铱的碳载铂基催化剂，铱的使用量通常高达铂的三分之一到五分之一，增加了燃料电池的制造成本。
中国专利申请CN113178582A公开了一种质子交换膜燃料电池抗反极阳极催化剂，所述抗反极阳极催化剂为碳纳米管负载的铂铱合金，阳极催化层使用该催化剂时无需额外添加抗反极添加剂，避免了直接加入铱或者氧化铱引起的团聚。但是该发明所提供的抗反极催化剂中铂铱摩尔比为6~1：1，铱的用量较大，同时铱的利用率不高，导致使用该催化剂制备的膜电极不具备显著增强的反极耐受性能。
中国专利申请CN112838224A公开了一种质子交换膜燃料电池膜电极抗反极添加剂及其制备方法，所述添加剂包括使用硼氢化钠还原法制备的自支撑式铱钴合金催化剂，阳极引入该发明所述抗反极添加剂后能够有效提高膜电极的抗反极性能，能有效缓解反极导致的阳极催化层的碳腐蚀和铂颗粒的团聚。但是该发明所述添加剂粒径高达100nm，而且该添加剂在阳极催化层中的载量较大，消耗较多铱的同时，会使催化层的厚度明显增加，导致大电流密度下膜电极传质阻抗增大。
中国专利申请CN111082078A公开了一种高性能且抗电压反极的膜电极组件的制备方法，所述的膜电极在阳极制备过程中添加铱钌单质或氧化物等电解水催化材料，阳极引入该催化材料后能有效减缓因欠气而造成的反极对膜电极性能的损害。但是该发明所述抗电压反极膜电极通过向阳极添加电解水催化材料获得，该催化材料在制备阳极浆料时难以分散均匀，而且金属氧化物的导电性较差，造成铱钌等金属或金属氧化物的有效利用率大幅度降低，膜电极反耐受性较低，导致铱钌等金属用量的增大和成本的提升，另外，向催化层直接添加金属或金属氧化物会造成金属颗粒的团聚，导致电解水催化活性降低。
铱为资源量极少的贵重金属元素，其价格十分昂贵，燃料电池膜电极中大量使用铱来实现抗反极除了受到资源限制之外，也会大大增加燃料电池的成本，妨碍燃料电池的大规模商业化进程。
为解决目前的抗反极技术中使用铱的量过高的问题，我们尝试采用少量铱以单原子的形式表面修饰商业碳载铂基催化剂，并以此催化剂制作耐逆阳极（RTA）, 我们发现极少量的高度分散铱表面修饰即可有效延长电极的逆转耐受时间。本发明既解决了燃料电池的抗反极难题，又大幅度降低了贵金属铱的用量，对于促进燃料电池大规模商业化具有重要意义。
 技术解决方案
燃料电池膜电极具有抗反极性能对于保障燃料电池的耐久性和稳定性具有重要意义，目前被广泛使用的抗反极的方法为在催化剂层中加入含有金属铱的碳载铂基抗反极催化剂，普遍存在铱金属使用量大的问题，导致燃料电池的成本升高，且抗反极效果一般。为了大幅度降低贵金属铱的使用量，提升金属铱的抗反极效果，降低燃料电池的成本，本发明提出了一种采用少量高度分散的铱表面修饰碳载铂基催化剂制备碳载铂基抗反极催化剂的方法，制得的催化剂具有抗反极效果好、铱使用量低等重要优点。使用本发明的碳载铂基抗反极催化剂在保障燃料电池的耐久性稳定性的同时，可有效降低燃料电池成本。同时，本发明还解决了直接向催化层添加抗反极催化材料的颗粒团聚和导电性差的问题。本发明解决了燃料电池商业化面临的一个重要问题，对于促进燃料电池大规模商业化具有重要意义。
本发明旨在提供一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂的制备方法，该催化剂应用于膜电极时能够显著提高燃料电池的抗反极性能，降低铱的用量。
为实现上述目的，本发明提供的技术方案为：
一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂的制备方法，利用铱络合物有机溶剂浸渍方式，使铱原子在碳载铂基催化剂的表面高度分散。
所述制备方法包括如下步骤：
步骤一、取少量金属铱前驱体，将其溶解后，加入络合剂，室温下搅拌均匀，制得铱的络合物溶液；
步骤二、称取适量碳载铂基催化剂，用少量去离子水润湿，加入步骤一中搅拌均匀的溶剂，超声30min；
步骤三、将步骤二中混合均匀的溶液转移到恒温水浴槽中，蒸干溶剂；
步骤四、将步骤三中蒸干溶剂后的催化剂转移到石英舟，置于管式炉中，在特定气氛下还原热处理，制得少量高度分散铱表面修饰的碳载铂基催化剂。
优选地，所述催化剂表面修饰负载的高度分散铱的含量为0.1%-5wt%。
优选地，步骤一中，所述的前驱体包括水合三氯化铱，氯铱酸，六氯铱酸铵，氯亚铱酸钾中的一种或两种。
优选地，步骤一中，所述的络合剂包括柠檬酸、酒石酸、水杨酸、EDTA中的一种或两种，络合剂与铱的比例为1：1-3：1（摩尔比）。
优选地，步骤一中，所述的铱络合物所使用的溶剂包括纯水和水与醇、酮组成的混合溶剂；所用醇类包括甲醇，乙醇，乙二醇，异丙醇中的一种以上，水和醇的体积比为1：1-1：5。所有酮类包括丙酮、环己酮等；
优选地，步骤二中，所述的碳载铂基催化剂包括碳载铂催化剂，以及碳负载的Pt与Ru、Fe、Ni、Co、Au或Pd形成的合金催化剂，催化剂中铂或铂合金含量为20%-60%。
优选地，步骤三中所述的恒温水浴槽温度控制在 50-80℃。
优选地，步骤四中所述的特定气氛包括氢气气氛，氢氩混合气气氛，氢氮混合气气氛，空气气氛中的一种。
优选地，步骤四中所述还原热处理的温度为100-800℃，热处理时间为0.5-5小时。
优选地，所述的高度分散铱的形式包括：单原子分散、原子簇分散和亚纳米分散。
本发明中，一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂，催化剂表面表面修饰负载的高度分散的铱的含量为0.1-5 wt%；所述的高度分散的铱的形式包括：单原子分散、原子簇分散和亚纳米分散。
本发明中，一种少量高度分散铱表面修饰的碳载铂基催化剂在燃料电池中作为阴极和阳极催化剂制备的膜电极具有优异的抗反极性能。
本发明制备的燃料电池催化剂的抗反极评价方法为：将少量高度分散铱表面修饰的铂碳催化剂作为膜电极的阳极和阴极催化剂，采用外电路给单电池施加0.2A/cm2的恒定电流，通过测试膜电极的反极时间，反极前后的单电池性能变化来评价催化剂的抗反极特性。
本发明侧重于燃料电池碳载铂基抗反极催化剂的结构，旨在利用少量高度分散的铱对碳载铂基催化剂进行表面修饰，使用少量的铱有效提高膜电极的抗反极性能，极大地提高铱的利用率。
 有益效果
与现有技术相比，本发明具有的优点在于：
1.极少量的铱直接负载在商业碳载铂基催化剂上，制备电极时，无需单独添加专门的铱基抗反极催化剂，避免了直接添加引起的颗粒团聚和导电性不足等问题。
2.铱以高度分散的形式存在于商业铂碳催化剂上，极大地提高了铱的利用率，能够大幅度减少铱的使用量，有效降低了燃料电池的抗反极成本。
3. 铱络合物有机溶剂浸渍技术，保证了铱在碳载铂基催化剂表面的高度分散。
 附图说明
图1为少量高度分散铱表面修饰燃料电池碳载铂基催化剂的原理图；
图2为实施例1、实施例2以及比较例催化剂的X射线衍射图；
图3为实施例1、实施例2以及比较例催化剂的氧析出（OER）活性对比图；
图4为实施例1、实施例2以及比较例催化剂的氧还原（ORR）活性对比图；
图5为实施例1、实施例2以及比较例催化剂的反极时间对比图；
图6为实施例1催化剂制备的膜电极反极前后的性能对比图；
图7为实施例2催化剂制备的膜电极反极前后的性能对比图；
图8为比较例催化剂制备的膜电极反极前后的性能对比图；
图9为反极前后实施例1，2以及比较例催化剂制备的膜电极在0.8A/cm2电流密度下的电压衰减对比图。
 本发明的实施方式
实施例1
碳载铂基抗反极催化剂的制备：步骤一、将2mg水合三氯化铱（铱含量54%）溶解到1ml水和乙醇的混合溶液中，水和醇体积比为1：5，加入柠檬酸，柠檬酸与铱的摩尔比为2：1，室温下搅拌均匀；
步骤二、称取200mgJM9100（60%Pt/C）催化剂，滴入少量去离子水润湿，与步骤一所得溶液混合，超声30min；
步骤三、将混合液转移到50℃恒温水浴槽中，蒸干溶剂；
步骤四、将步骤三中所得催化剂转移到石英舟，置于管式炉中，在氢氩混合气气氛中热处理，热处理温度为300℃，热处理时间为2h，冷却至室温后得到铱含量为0.54%（Pt/Ir质量比≈110：1）的碳载铂基催化剂。
将上述催化剂制备成阳极和阴极催化层：称取0.87mg催化剂，适量的5%Nafion溶液以及异丙醇配制成催化剂浆料，其中阳极催化剂载量为0.1mg/cm 2（以贵金属计)，阴极催化剂载量为0.2mg/cm 2（以贵金属计），浆料超声分散后均匀喷涂到Nafion211膜两侧，制得膜电极。
将上述膜电极组装至燃料电池中，进行电池性能和抗反极测试，电池性能测试的条件如下：阳极燃料为氢气，阴极氧化剂为空气，电池温度为80℃，阴阳极相对湿度为100%，阴阳极背压为200kPa。抗反极测试条件如下：电池温度80℃，阴阳极相对湿度为100%，阴阳极背压为0，阳极进气为高纯氢气，阴极为空气，外接恒流源，保证电流为0.2A/cm 2（阳极接恒流源正极），待膜电极电压稳定之后将阳极高纯氢气切换为高纯氮气，其他条件保持不变，设置截至电压为-2V，到达截至电压时模拟反极停止，记录燃料电池反极时间。
 
实施例2
碳载铂基抗反极催化剂的制备：步骤一、将质量为0.74mg的水合三氯化铱溶解到1ml水和甲醇的混合溶液中，水和甲醇的体积比为1：2，加入水杨酸，混合溶液中水杨酸与铱的摩尔比为3：1，室温下搅拌均匀；
步骤二、称取200mgJM9100催化剂，用去离子水润湿，与步骤一所得溶液混合，超声30min；
步骤三、将混合液转移到80℃恒温水浴槽中，蒸干溶剂；
步骤四、将步骤三中所得催化剂转移到石英舟，置于管式炉中，在空气气氛中焙烧，焙烧温度为200℃，热处理时间为2h，冷却至室温后得到铱含量为0.20%（Pt/Ir质量比≈300：1）的碳载铂基催化剂。
上述催化剂制备膜电极，进行燃料电池性能和抗反极测试的方法同实施例1。
 
比较例：
采用相同方法，与实施例1的区别在于，抗反极膜电极阴极和阳极催化层使用的催化剂均为未经过铱络合物浸渍处理的商业JM9100催化剂。
 
图1为本发明制备的少量高度分散铱表面修饰的碳载铂基抗反极催化剂的原理图。
图2为实施例1，2以及比较例催化剂的XRD图，可以看到经过铱络合物有机溶剂浸渍处理后，仅催化剂的颗粒尺寸发生了变化。
图3，图4为实施例1，2以及比较例催化剂的LSV测试图，可以看到碳载铂基催化剂经过铱络合物有机溶剂浸渍处理后，催化剂的ORR活性和导电性未发生明显变化，OER活性显著增强。
图5为实施例1，2以及比较例催化剂进行抗反极测试的反极时间曲线，可以看到经过少量高度分散铱表面修饰后，实施例1和2的抗反极时间分别是比较例的3.38倍和2倍。
图6、图7和图8分别为实施例1，2以及比较例催化剂反极前后的燃料电池极化曲线，图9为上述几种催化剂反极前后的电压衰减对比图，反极测试前，由于铱在催化剂表面高度分散，催化剂的活性和导电性并未受到影响。反极测试后，在800mA/cm2电流密度下，比较例的电压衰减高达124mV，而实施例1和2的电压衰减仅为40mV和45mV。
因此，本发明提供的碳载铂基抗反极催化剂能够有效提高燃料电池的逆转耐受性。
 
实施例3
除以下改变外，其它同实施例1；
（1）     将铱前驱体改为0.4mg氯亚铱酸钾， 水和乙醇的体积比改为1：4，络合剂为EDTA，络合剂与铱的摩尔比为1：1；
（2）     将恒温水浴槽的温度调整为70℃；
（3）     将热处理温度改为100℃，热处理时间缩短为1h。
与实施例1，2一致，浸渍处理后的催化剂具有显著增强的OER活性，将其作为催化层的活性组分，制备得到具有优异抗反极性能的膜电极，性能测试和抗反极测试表明，催化层使用该催化剂的膜电极逆转耐受性显著提升。
 
实施例4
除以下改变外，其它同实施例1；
（1）     将铱前驱体改为11mg六氯铱酸铵，溶剂改为体积比为1：1的水和乙二醇混合溶液，络合剂为酒石酸，酒石酸与铱的摩尔比为3：1；
（2）     将JM9100催化剂改为JM3000催化剂（20%Pt/C）；
（3）     热处理时，热处理温度改为800℃，热处理时间延长为5h。
与实施例1，2一致，浸渍处理后催化剂的OER活性显著增强，由于足够的铱在催化剂表面高度分散，以该催化剂座位活性组分的膜电极具有优异的抗反极性能，水电解时间大幅度提高。
 
实施例5
除以下改变外。其它同实施例1；
（1）     将水合三氯化铱的量改为5mg，溶剂改为体积比为1：2的水和异丙醇混合溶液；
（2）     将JM9100催化剂改为JM4100催化剂（40%Pt/C）；
（3）     热处理时，氢氩气氛改为氢气气氛，热处理温度改为500℃，热处理时间延长为2.5h。
与实施例1，2一致，由于铱高度分散在催化剂表面，该催化剂具有显著增强的OER活性，以该催化剂做为活性组分制备的膜电极具有优异的逆转耐受性，初始抗反极时间大幅度提高。
 
实施例6
除以下改变外，其它同实施例1；
（1）     将铱络合物改为3mg的氯铱酸；
（2）     将恒温水浴的温度调整为60℃；
（3）     热处理时，氢氩气氛改为氢氮气氛，热处理温度提高到400℃，热处理温度延长为3h。
与实施例1，2一致，铱络合物浸渍热处理之后的催化剂具有几乎不变的ORR活性与显著增强的OER活性，将其作为催化层的活性组分，制备得到的膜电极具有显著增强的逆转耐受性。
 
实施例7
除以下改变外，其它同实施例1；
（1）     将络合剂改为EDTA；
（2）     将JM9100催化剂改为铂含量为40%的PtAu/C催化剂；
（3）     热处理时，氢气气氛改为空气气氛，热处理时间缩短为1.5h。
与实施例1，2一致，少量高度分散铱表面修饰后，以该催化剂制备的膜电极具有优异的抗反极性能，燃料电池的水电解时间得到有效延长。
 
实施例8：
除以下改变外，其它同实施例1:
(1)   将溶剂改为体积比为1：4的水和乙二醇的混合溶液，络合剂改为水杨酸；
(2)   热处理时，将氢氩气氛改为氢气气氛，热处理温度提高为600℃，热处理时间缩短至0.5h，
与实施例1，2一致，由于少量铱以高度分散的形式存在催化剂的表面，以该催化剂制备的膜电极具有显著增强的逆转耐受性。

Claims (10)

  1. 一种少量高度分散铱表面修饰的燃料电池铂基抗反极催化剂的制备方法，其特征在于：采用铱络合物溶液浸渍铂基催化剂，然后通过在特定气氛下热处理，使还原出来的铱原子高度分散在碳载铂基催化剂表面；
    包括如下步骤 ：
    步骤一、将铱前驱体溶解到溶剂中，加入络合剂，室温下搅拌均匀，制得铱的络合物的溶液；
    步骤二、称取铂基催化剂，用去离子水润湿，与步骤一所得溶液混合，超声；
    步骤三、将上述混合物转移到恒温水浴槽中，蒸干溶剂；
    步骤四、将蒸干溶剂后的物料转移到石英舟，置于管式炉中，在特定气氛下还原热处理，制得表面修饰有少量高度分散铱的铂基催化剂。
  2. 根据权利要求1所述一种少量高度分散铱表面修饰的燃料电池铂基抗反极催化剂的制备方法，其特征在于：步骤一中，所述铱前驱体包括水合三氯化铱、氯铱酸、六氯铱酸铵、氯亚铱酸钾中的一种或者一种以上的混合物。
  3. 根据权利要求1所述一种少量高度分散铱表面修饰的燃料电池铂基抗反极催化剂的制备方法，其特征在于：步骤一中，所述的络合剂包括柠檬酸、酒石酸、水杨酸、EDTA中的一种以上，络合剂与铱的摩尔比为1：1 – 3：1。
  4. 根据权利要求1所述一种少量高度分散铱表面修饰的燃料电池铂基抗反极催化剂的制备方法，其特征在于：步骤一中，所述溶剂包括纯水、以及纯水与醇、酮等形成的混合物，所述醇类包括甲醇，乙醇，乙二醇，异丙醇中的一种或者一种以上，水和醇的体积比为1：1~1：5；所属同类包括丙酮、环己酮中的一种。
  5. 根据权利要求1所述一种少量高度分散铱表面修饰的燃料电池铂基抗反极催化剂的制备方法，其特征在于：步骤二中，所述碳载铂基催化剂包括碳载铂催化剂和碳负载铂基合金催化剂，催化剂中铂或铂合金含量为20%~60%；所述碳负载铂基合金催化剂中的合金为Pt与Ru、Fe、Ni、Co、Au或Pd中的一种以上形成的合金。
  6. 根据权利要求1所述一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂的制备方法，其特征在于：步骤三中，所述的恒温水浴槽温度控制在50~80℃。
  7. 根据权利要求1所述一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂的制备方法，其特征在于：步骤四中，所述特定气氛包括氢气气氛，氢氩混合气气氛，氢氮混合气气氛，空气气氛中的一种。
  8. 根据权利要求1所述一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂的制备方法，其特征在于：所述热处理步骤的温度为100~800℃，热处理时间为0.5-5小时。
  9. 权利要求1所述制备方法制备得到一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂，其特征在于：催化剂表面修饰负载的高度分散的铱的含量为0.1-5 wt%；
    所述的高度分散的铱的形式包括：单原子分散、原子簇分散和亚纳米分散。
  10. 权利要求9所述少量高度分散铱表面修饰的碳载铂基催化剂在燃料电池中作为阴极和阳极催化剂制备的膜电极具有优异的抗反极性能。
PCT/CN2022/135189 2021-12-17 2022-11-29 一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用 WO2023109510A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202111556618.2A CN114361478A (zh) 2021-12-17 2021-12-17 一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用
CN202111556618.2 2021-12-17

Publications (1)

Publication Number Publication Date
WO2023109510A1 true WO2023109510A1 (zh) 2023-06-22

Family

ID=81099496

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/135189 WO2023109510A1 (zh) 2021-12-17 2022-11-29 一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用

Country Status (2)

Country Link
CN (1) CN114361478A (zh)
WO (1) WO2023109510A1 (zh)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114361478A (zh) * 2021-12-17 2022-04-15 华南理工大学 一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用
CN115207369B (zh) * 2022-07-06 2024-08-27 国联汽车动力电池研究院有限责任公司 一种燃料电池阳极抗反极催化剂及其制备方法
CN115312795A (zh) * 2022-08-31 2022-11-08 广州市香港科大霍英东研究院 一种提升燃料电池铂基催化剂耐久性的方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104600327A (zh) * 2014-12-19 2015-05-06 上海交通大学 一种碳载纳米铂合金催化剂的制备方法
KR20200050216A (ko) * 2018-11-01 2020-05-11 현대자동차주식회사 연료 전지용 백금계 합금 촉매의 제조 방법 및 이로부터 제조되는 백금계 합금 촉매
CN112952118A (zh) * 2020-12-22 2021-06-11 华南理工大学 一种高度稳定和具有抗反极性能的高Pt含量高性能催化剂及其制备方法
CN114361478A (zh) * 2021-12-17 2022-04-15 华南理工大学 一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104600327A (zh) * 2014-12-19 2015-05-06 上海交通大学 一种碳载纳米铂合金催化剂的制备方法
KR20200050216A (ko) * 2018-11-01 2020-05-11 현대자동차주식회사 연료 전지용 백금계 합금 촉매의 제조 방법 및 이로부터 제조되는 백금계 합금 촉매
CN112952118A (zh) * 2020-12-22 2021-06-11 华南理工大学 一种高度稳定和具有抗反极性能的高Pt含量高性能催化剂及其制备方法
CN114361478A (zh) * 2021-12-17 2022-04-15 华南理工大学 一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用

Also Published As

Publication number Publication date
CN114361478A (zh) 2022-04-15

Similar Documents

Publication Publication Date Title
WO2023109510A1 (zh) 一种少量高度分散铱表面修饰的燃料电池碳载铂基抗反极催化剂及其制备方法与应用
TWI404258B (zh) 具有改良壽命特性之電極觸媒以及使用該觸媒之燃料電池
US7579298B2 (en) Catalyst, electrode for fuel electrode in fuel cell, and fuel cell
CN111900420A (zh) 一种阳极催化剂浆料、阳极催化剂层、膜电极及燃料电池
CN115036522B (zh) 一种限域制备燃料电池用合金催化剂的方法
WO2019179530A1 (zh) 一种铂基合金催化剂及其制备方法、膜电极及燃料电池
CN108539206B (zh) 一种催化层全有序燃料电池电极和膜电极
CN108075144B (zh) 一种燃料电池用核壳结构催化剂及制备和应用
Li et al. Platinum-tellurium alloy metallene toward formic acid oxidation reaction
WO2021114056A1 (zh) 燃料电池阴极催化剂及其制备方法、膜电极及燃料电池
CN110911700B (zh) 催化剂及其制备方法和应用
WO2021088959A1 (zh) 一种多孔双空心球结构的PtAg纳米晶及其制备方法和应用
US10998556B2 (en) Catalyst for solid polymer fuel cell and method for producing same
CN114855214B (zh) 一种抗反极催化剂及其制备方法和用途
Mukherjee et al. Methodical designing of Pt3− xCo0. 5+ yNi0. 5+ y/C (x= 0, 1, 2; y= 0, 0.5, 1) particles using a single-step solid state chemistry method as efficient cathode catalyst in H2-O2 fuel cells
CN113036162A (zh) 一种碳载体铂基核壳结构催化剂、制备方法及应用
JP2001224969A (ja) 合金触媒の調製方法及び固体高分子型燃料電池の製造方法
CN108336375A (zh) 一种锯齿状金属纳米线-碳基燃料电池催化剂及制备方法
CN109301269B (zh) 一种PtAgCo/C纳米花结构催化材料及其制备方法和作为燃料电池催化剂的应用
Miyamoto et al. Pt-Ta-Co electrocatalysts for polymer electrolyte fuel cells
CN115472846A (zh) 碳载铑基有序金属间化合物及制备与作为催化剂的应用
CN115440994A (zh) 一种聚合物电解质燃料电池催化剂的微波制备工艺
CN114171750A (zh) 一种用于燃料电池膜电极的阳极催化剂及其制备方法
CN110783580B (zh) 一种碱性体系燃料电池阳极催化剂的制备方法
TW202131544A (zh) 具高耐受性之燃料電池電極、其製造方法以及包括其之膜電極組合

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22906260

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE