WO2021102739A1 - 膜电极及其制备方法、燃料电池 - Google Patents

膜电极及其制备方法、燃料电池 Download PDF

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WO2021102739A1
WO2021102739A1 PCT/CN2019/121277 CN2019121277W WO2021102739A1 WO 2021102739 A1 WO2021102739 A1 WO 2021102739A1 CN 2019121277 W CN2019121277 W CN 2019121277W WO 2021102739 A1 WO2021102739 A1 WO 2021102739A1
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catalyst
anode
membrane electrode
layer
catalyst layer
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PCT/CN2019/121277
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English (en)
French (fr)
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张晓华
吴丹
范书琼
米诗阳
朱威
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苏州擎动动力科技有限公司
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Priority to PCT/CN2019/121277 priority Critical patent/WO2021102739A1/zh
Priority to EP19954609.4A priority patent/EP4068435A1/en
Priority to CN201980049374.3A priority patent/CN112534613B/zh
Publication of WO2021102739A1 publication Critical patent/WO2021102739A1/zh

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    • 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
    • H01M8/1004—Fuel cells with solid electrolytes characterised by membrane-electrode assemblies [MEA]
    • 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
    • H01M4/8803—Supports for the deposition of the catalytic active composition
    • H01M4/8807—Gas diffusion layers
    • 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
    • H01M4/8825—Methods for deposition of the catalytic active composition
    • H01M4/8828—Coating with slurry or ink
    • 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
    • H01M4/8825—Methods for deposition of the catalytic active composition
    • H01M4/886—Powder spraying, e.g. wet or dry powder spraying, plasma spraying
    • 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
    • H01M4/921—Alloys or mixtures with metallic elements
    • 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
    • H01M4/923—Compounds thereof with non-metallic elements
    • 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
    • H01M4/925—Metals of platinum group supported on carriers, e.g. powder carriers
    • H01M4/926—Metals of platinum group supported on carriers, e.g. powder carriers on carbon or graphite
    • 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
    • H01M2008/1095—Fuel cells with polymeric 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

  • This application relates to the technical field of fuel cells, in particular to a membrane electrode, a preparation method thereof, and a fuel cell.
  • Proton Exchange Membrane Fuel Cell is a device that converts hydrogen energy into electrical energy. Its final emission is only water. It is a clean, green and pollution-free power generation device. It is used in automobiles, ships, and rail transit. , Fixed base stations, unmanned aerial vehicles and other fields have broad application prospects.
  • the core component inside the proton exchange membrane fuel cell is called Membrane Electrode Assembly (MEA, Membrane Electrode Assembly), which is the smallest unit of power generation.
  • MEA Membrane Electrode Assembly
  • Cell Reversal is one of the harsh conditions encountered during the operation of membrane electrodes. Specifically, when a single or multiple membrane electrodes are blocked due to water blocking or condensation on the anode during the operation of the stack, the hydrogen transmission at the anode is blocked and cannot reach the surface of the catalyst Pt to produce protons. In order to maintain the current (proton flow) before the reverse electrode, the potential of the anode rises from 0V before the reverse electrode (compared to the standard hydrogen electrode, SHE) to higher than 1.5V in a short time. At this time, the voltage of the membrane electrode is usually lower than -1V. ; Under the high anode potential, the carbon component reacts with water, and the carbon corrodes to generate proton maintenance current. Carbon continues to corrode, eventually leading to the failure of the membrane electrode.
  • the existing membrane electrode cannot well reduce the performance loss after the reverse electrode, and the anti-reverse electrode ability of the membrane electrode is not strong.
  • the purpose of this application is to provide a membrane electrode, a preparation method thereof, and a fuel cell, which can effectively reduce the performance loss after the reverse electrode, prolong the reverse electrode tolerance time, and enhance the anti-reverse electrode ability of the membrane electrode.
  • the embodiment of the present application provides a membrane electrode including a proton exchange membrane, an anode catalyst and an anode diffusion layer.
  • the anode catalyst includes a first catalyst layer and a second catalyst layer.
  • the proton exchange membrane, the first catalyst layer, the second catalyst layer and the anode diffusion layer are arranged in sequence.
  • the first catalyst layer includes a hydroxide catalyst
  • the second catalyst layer includes a mixed hydroxide catalyst and a water electrolysis catalyst.
  • a water electrolysis catalyst on the side of the anode catalyst layer close to the anode diffusion layer.
  • the reverse polarity occurs, the carbon corrosion at the water electrolysis catalyst can be reduced, and the water electrolysis catalyst electrolyzes the water on the side close to the anode diffusion layer.
  • Providing proton flow for the proton exchange membrane can reduce the carbon corrosion at the hydroxide catalyst and prolong the anti-polarity tolerance time.
  • Both the side of the anode catalyst layer close to the proton exchange membrane and the side close to the anode diffusion layer have a hydroxide catalyst. When there is enough hydroxide catalyst to provide proton flow, part of the hydroxide catalyst is formed on the anode catalyst layer.
  • the side close to the anode diffusion layer can further reduce the carbon corrosion of the hydroxide catalyst, reduce the performance loss after the reverse electrode, and prolong the resistance time of the reverse electrode.
  • Figure 1 is a cross-sectional view of a membrane electrode provided by an embodiment of the application.
  • Figure 2 shows the effect of Pt(Ir) mass fraction on performance loss after reverse polarity
  • Figure 3 shows the effect of membrane electrode recovery overnight on performance loss after reverse polarity
  • Figure 4 shows the effect of graphitization of carbon support on the resistance time of reverse polarity
  • Figure 5 shows the influence of the distribution of the HOR catalyst on the performance loss of the simulated reverse polarity
  • Figure 6 shows the influence of HOR catalyst distribution on performance loss after reverse polarity (Example 1 and Comparative Example 5);
  • Figure 7 shows the influence of the distribution of the HOR catalyst on the performance loss after reverse polarity (Example 2 and Comparative Example 10).
  • Icon 30-membrane electrode; 310-cathode diffusion layer; 320-cathode catalyst layer; 330-proton exchange membrane; 340-anode catalyst layer; 350-anode diffusion layer; 341-first catalyst layer; 342-second catalyst layer .
  • FIG. 1 is a cross-sectional view of a membrane electrode 30 provided by an embodiment of the application.
  • the membrane electrode 30 includes a cathode diffusion layer 310, a cathode catalyst layer 320, a proton exchange membrane 330, an anode catalyst layer 340, and an anode diffusion layer 350 arranged in sequence.
  • the anode catalyst layer 340 includes a first catalyst layer 341 and a second catalyst layer 342.
  • the cathode diffusion layer 310, the cathode catalyst layer 320, the proton exchange membrane 330, the first catalyst layer 341, the second catalyst layer 342, and the anode diffusion layer 350 are arranged in sequence. cloth.
  • the first catalyst layer 341 includes a hydroxide catalyst
  • the second catalyst layer 342 includes a mixed hydroxide catalyst and a water electrolysis catalyst.
  • a hydrogen oxidizing catalyst is formed on the side of the anode catalyst layer 340 close to the proton exchange membrane 330 and the side close to the anode diffusion layer 350, when there is enough hydrogen oxidizing catalyst to provide proton flow, the partial hydrogen oxidizing catalyst Formed on the side of the anode catalyst layer 340 close to the anode diffusion layer 350, the water content near part of the hydrogen oxidizing catalyst can be reduced, the carbon corrosion of the hydrogen oxidizing catalyst can be reduced, and the performance loss after the reverse electrode can be reduced.
  • a water electrolysis catalyst is provided on the side of the anode catalyst layer 340 close to the anode diffusion layer 350.
  • Electrolysis can provide a flow of protons for the proton exchange membrane, which can reduce carbon corrosion at the hydrogen oxidizing catalyst and prolong the anti-polarity tolerance time.
  • the water electrolysis catalyst includes a first carrier and an active component of the water electrolysis catalyst supported on the first carrier.
  • the oxidizing catalyst includes a second carrier and an active component of the oxidizing catalyst supported on the second carrier.
  • the active ingredients can be carried on a corrosion-resistant carrier.
  • the anode support (that is, the first support and the second support) may be conductive metal oxide or graphitic carbon. Both graphitic carbon and conductive metal oxide are resistant to high potential (above 1.5V) corrosion.
  • the use of conductive metal oxide or graphitic carbon as the anode support of the active material can prolong the anti-electrode endurance time.
  • the conductive metal oxide does not contain carbon, which can avoid carbon corrosion.
  • the conductive metal oxide is selected from one of Ti 4 O 7 , Nb-TiO 2 and ITO.
  • Graphitized carbon can be a graphitized carbon material. After carbon is graphitized, it can reduce carbon corrosion.
  • the active component of the water electrolysis catalyst may be one or more of RuO 2 , IrO 2 , and Ru x Ir 1-x O 2.
  • the water electrolysis catalyst active component can be RuO 2 ; the water electrolysis catalyst active component can be IrO 2 ; the water electrolysis catalyst active component can be Ru x Ir 1-x O 2 ; the water electrolysis catalyst active component can be RuO 2 and IrO 2
  • the active component of the water electrolysis catalyst can be a mixture of RuO 2 and Ru x Ir 1-x O 2 ; the active component of the water electrolysis catalyst can be a mixture of IrO 2 and Ru x Ir 1-x O 2 ; the active component of the water electrolysis catalyst It can be a mixture of RuO 2 , IrO 2 and Ru x Ir 1-x O 2.
  • the active component of the water electrolysis catalyst is not limited, as long as it can be used as the active component of the water electrolysis catalyst, it falls within the protection scope of this application.
  • the water electrolysis catalyst can provide proton flow through water electrolysis, and can reduce the potential of water electrolysis, make the anode potential relatively low, reduce carbon corrosion, and can reduce the performance loss after the reverse electrode while ensuring the resistance time of the reverse electrode .
  • the mass percentage of the active component of the water electrolysis catalyst in the water electrolysis catalyst is 10%-80%.
  • the mass percentage of the active component in the water electrolysis catalyst is 40%-80%.
  • the active component of the hydrogen oxidation catalyst is a metal catalyst, including one or more of Pt, Ir, PtIr alloy, and Pd.
  • the active component of the hydrogen oxidizing catalyst can be Pt; the active component of the oxidizing catalyst can be Ir; the active component of the oxidizing catalyst can be PtIr alloy; the active component of the oxidizing catalyst can be Pd.
  • the active component of the hydrogen oxidizing catalyst is not limited, as long as it can be used as the active component of the hydrogen oxidizing catalyst, it falls within the protection scope of this application.
  • the mass percentage of the active component of the hydrogenation catalyst in the hydrogenation catalyst is 10%-80%.
  • the mass percentage of Pt in the hydroxide catalyst is 40%-80%.
  • the types of the oxidizing catalyst in the first catalyst layer 341 and the oxidizing catalyst in the second catalyst layer 342 may be the same or different.
  • the active component of the oxidizing catalyst in the first catalyst layer 341 is Pt, and the active component of the oxidizing catalyst in the second catalyst layer 342 is also Pt; or the active component of the oxidizing catalyst in the first catalyst layer 341 is Pt ,
  • the active component of the oxidizing catalyst in the second catalyst layer 342 is Ir; or the active component of the oxidizing catalyst in the first catalyst layer 341 is Ir, and the active component of the oxidizing catalyst in the second catalyst layer 342 is Pt.
  • the mass ratio of the hydroxide catalyst in the first catalyst layer 341 to the hydroxide catalyst in the second catalyst layer 342 may be 1:10-1:0.1. Further, the mass ratio of the hydroxide catalyst in the first catalyst layer 341 and the hydroxide catalyst in the second catalyst layer 342 may be 1:5-1:0.5. Further, the mass ratio of the hydroxide catalyst in the first catalyst layer 341 and the hydroxide catalyst in the second catalyst layer 342 may be 1:2-1:0.8. Further, the mass ratio of the hydroxide catalyst in the first catalyst layer 341 and the hydroxide catalyst in the second catalyst layer 342 may be 1:1.
  • the preparation method of the obtained membrane electrode 30 may be: forming the oxidizing catalyst on the anode side of the proton exchange membrane 330 to obtain the first catalyst layer 341, and forming the mixed oxidizing catalyst and the water electrolysis catalyst on the anode side of the proton exchange membrane 330.
  • the anode diffusion layer 350 obtains the second catalyst layer 342, and the first catalyst layer 341 and the second catalyst layer 342 are bonded together.
  • the first catalyst layer 341 is obtained by forming the hydrogen oxidizing catalyst on the anode side of the proton exchange membrane 330, and forming the mixed oxidizing catalyst and the water electrolysis catalyst on the side of the first catalyst layer 341 facing away from the proton exchange membrane 330 to obtain the second catalyst layer.
  • the catalyst layer 342 forms the anode diffusion layer 350 on the side of the second catalyst layer 342 away from the first catalyst layer 341.
  • the above-mentioned membrane electrode 30 can be obtained.
  • the membrane electrode 30 obtained by the above method can not only prolong the resistance time of the reverse polarity of the membrane electrode, but also reduce the performance loss after the reverse polarity of the membrane electrode.
  • the above-mentioned membrane electrode is used to prepare a fuel cell, and the performance of the fuel cell is better.
  • cathode catalyst is 60% Pt/C (Ketjen black)
  • anode HOR catalyst hydrooxide catalyst
  • Pt/GrC graphitized Ketjen black
  • anode OER catalyst water electrolysis catalyst
  • IrO 2 /GrC graphitized Ketjen Black
  • Cathode catalyst is 60% Pt/C
  • anode HOR catalyst is 40% Pt/GrC
  • layered structure design anode OER catalyst is 40% IrO 2 /GrC.
  • the Pt loading in the cathode catalyst is 0.4 mg Pt /cm 2 , and it is sprayed on the cathode side of the CCM (Proton Exchange Membrane).
  • the loading of Pt in the anode HOR catalyst is 0.1 mg Pt /cm 2
  • the loading of IrO 2 in the OER catalyst is 0.05 mg Ir /cm 2 .
  • Half of the anode HOR catalyst (0.05mg Pt /cm 2 ) is sprayed on the anode side of the CCM, and the other half (0.05mg Pt /cm 2 ) of the anode HOR catalyst is mixed with the anode OER catalyst (0.05mg Ir /cm 2 ). Spray on anode GDL.
  • the anti-reverse polarity test is the same as that of Comparative Example 1. After the reverse polarity is over, the membrane electrode is placed for 10 hours and undergoes an overnight recovery (overnight recovery), the V-I curve after the reverse polarity is tested and the performance loss is compared.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 70% Pt/GrC
  • the anode OER catalyst is 70% IrO 2 /GrC.
  • Cathode catalyst is 60% Pt/C
  • anode HOR catalyst is 70% Pt/GrC
  • layered structure design anode OER catalyst is 70% IrO 2 /GrC.
  • the loading of Pt in the cathode catalyst is 0.4 mg Pt /cm 2 , and it is sprayed on the cathode side of the CCM.
  • the loading of Pt in the anode HOR catalyst is 0.1 mg Pt /cm 2
  • the loading of IrO 2 in the OER catalyst is 0.05 mg Ir /cm 2 .
  • Half of the anode HOR catalyst (0.05mg Pt /cm 2 ) is sprayed on the anode side of the CCM, and the other half (0.05mg Pt /cm 2 ) of the anode HOR catalyst is mixed with the anode OER catalyst (0.05mg Ir /cm 2 ). Spray on anode GDL.
  • the anti-reverse polarity test is the same as that of Comparative Example 1. After the reverse polarity is over, the membrane electrode is placed for 10 hours and undergoes an overnight recovery. The V-I curve after the reverse polarity is tested and the performance loss is compared.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 40% Pt/GrC
  • the anode OER catalyst is 40% IrO 2 /GrC.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 40% Pt/GrC
  • the anode OER catalyst is 40% IrO 2 /GrC.
  • the loading of Pt in the cathode catalyst is 0.4 mg Pt /cm 2 , and it is sprayed on the cathode side of the CCM.
  • the loading of Pt in the anode HOR catalyst is 0.1 mg Pt /cm 2 , sprayed on the anode side of the CCM
  • the loading of IrO 2 in the OER catalyst is 0.1 mg Ir /cm 2 , sprayed on the anode diffusion layer (GDL).
  • the conditions for the anti-reverse test are:
  • Anode flow rate 1slpm
  • cathode flow rate 1slpm
  • test temperature 75°C
  • relative humidity anode 100% RH
  • test pressure normal pressure
  • the time from the start of the reversal to the end of the reversal is the reversal tolerance time. During this time, it is the N 2 /Air state that simulates the lack of H 2.
  • the VI curve after testing the reverse polarity compares the performance loss.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 70% Pt/GrC
  • the anode OER catalyst is 70% IrO 2 /GrC.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 70% Pt/GrC
  • the anode OER catalyst is 70% IrO 2 /GrC.
  • the loading of Pt in the cathode catalyst is 0.4 mg Pt /cm 2 , and it is sprayed on the cathode side of the CCM.
  • the loading of Pt in the anode HOR catalyst is 0.1mg Pt /cm 2 , sprayed on the anode side of the CCM
  • the loading of IrO 2 in the OER catalyst is 0.1mg Ir /cm 2 , sprayed on the anode GDL.
  • the anti-reverse polarity test is the same as that of Comparative Example 1. After the reverse polarity is over, test the V-I curve after the reverse polarity and compare the performance loss.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 70% Pt/GrC.
  • the cathode catalyst is 60% Pt/C, and the anode HOR catalyst is 70% Pt/GrC, with a layered structure design.
  • the loading of Pt in the cathode catalyst is 0.4 mg Pt /cm 2 , and it is sprayed on the cathode side of the CCM.
  • the loading of Pt in the anode HOR catalyst is 0.1mg Pt /cm 2 , of which 0.05mg Pt /cm 2 is sprayed on the anode side of the CCM and 0.05mg Pt /cm 2 is sprayed on the anode GDL.
  • Simulated reverse polarity test anode flow rate: 0.5 slpm, cathode flow rate: 0.5 slpm, test temperature: 80°C, relative humidity: anode 45% RH, cathode 45% RH, test pressure: 0.5 bar, 0.5 bar.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 70% Pt/GrC.
  • the loading of Pt in the cathode catalyst was 0.4 mg Pt /cm 2 , sprayed on the cathode side of the CCM, and the loading of Pt in the anode HOR catalyst was 0.1 mg Pt /cm 2 , sprayed on the anode side of the CCM.
  • the simulated reverse polarity test is the same as that of Comparative Example 3. After the simulated reverse polarity is completed, the membrane electrode is placed for 10 hours and undergoes an overnight recovery, and the V-I curve after the simulated reverse polarity is tested and the performance loss is compared.
  • HOR catalyst preparation of HOR catalyst, OER catalyst and membrane electrode is the same as that of Comparative Example 1.
  • the anti-reverse electrode test is also the same as that of Comparative Example 1.
  • the membrane electrode is placed for 10 hours and subjected to an overnight recovery, and then compared before and after the reverse electrode The performance loss.
  • HOR catalyst preparation of HOR catalyst, OER catalyst and membrane electrode is the same as that of Comparative Example 2.
  • the anti-reverse electrode test is also the same as that of Comparative Example 1. After the reverse electrode test, the membrane electrode is placed for 10 hours and undergoes an overnight recovery, and then compare before and after reverse polarity The performance loss.
  • the preparation of the HOR catalyst, the OER catalyst and the membrane electrode is the same as that of Comparative Example 1, and the anti-reverse electrode test is also the same as that of Comparative Example 1, but the reverse electrode tolerance time is 60 minutes. After the reverse polarity test, the membrane electrode was placed for 10 hours and subjected to an overnight recovery (overnight recovery), and then the performance loss before and after the reverse polarity was compared.
  • the preparation of the HOR catalyst, the OER catalyst and the membrane electrode is the same as that of Comparative Example 2, and the anti-reverse electrode test is also the same as that of Comparative Example 2, but the reverse electrode tolerance time is 60 minutes. After the reverse polarity test, the membrane electrode was placed for 10 hours and subjected to an overnight recovery (overnight recovery), and then the performance loss before and after the reverse polarity was compared.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 60% Pt/C
  • the anode OER catalyst is 40% IrO 2 /C.
  • the loading of Pt in the cathode catalyst is 0.4mg Pt /cm 2 , sprayed on the cathode side of the CCM
  • the loading of Pt in the anode HOR catalyst is 0.1mg Pt /cm 2 , sprayed on the anode side of the CCM
  • the IrO 2 in the anode OER catalyst The load is 0.1mg Ir /cm 2 , sprayed on the anode GDL.
  • the anti-reverse pole test is the same as in Example 1. After the reverse polarity is over, test the V-I curve after the reverse polarity and compare the performance loss.
  • the cathode catalyst is 60% Pt/C
  • the anode HOR catalyst is 70% Pt/GrC
  • the anode OER catalyst is 70% IrO 2 /GrC.
  • the loading of Pt in the cathode catalyst is 0.4 mg Pt /cm 2 , and it is sprayed on the cathode side of the CCM.
  • the Pt loading in the anode HOR catalyst is 0.1 mg Pt /cm 2 , sprayed on the anode side of the CCM.
  • the loading of IrO 2 in the anode OER catalyst is 0.05 mg Ir /cm 2 , which is sprayed on the anode GDL.
  • the reverse polarity test is the same as that of Comparative Example 1. After the reverse polarity is over, the membrane electrode is placed for 10 hours and undergoes an overnight recovery. The V-I curve after the reverse polarity is tested and the performance loss is compared.
  • the voltage loss in the small current area (LCD, 0.2A/cm 2 ) and the voltage loss in the high current area (HCD, 1A/cm 2 ) are selected here to comprehensively reflect the performance loss before and after the reverse polarity.
  • the membrane electrode components and test conditions of Example 1 to Example 2 and Comparative Example 1 to Comparative Example 10 are shown in Table 1:
  • Table 2 Using the membrane electrode and its test conditions described in Table 1 to perform the initial performance of the membrane electrode and comparing the performance after reverse polarity, Table 2 is obtained.
  • Example 2 Furthermore, from the comparison of Example 1 and Example 2, it can be seen that when the HOR catalyst is distributed in the area close to the membrane and the area close to the anode diffusion layer, the high Pt(Ir) mass fraction reduces the amount of carbon support, making it more Less carbon corrodes, which significantly prolongs the anti-polarity endurance time.
  • Example 1 when the reverse pole endurance time is the same, the performance loss of the HOR catalysts respectively distributed in the area near the membrane and the area near the anode diffusion layer is lower than that of the HOR catalysts.
  • the area close to the membrane proves that the double-layer design of HOR catalyst is beneficial to reduce the performance loss after reverse polarity.
  • Figure 6 the influence of the distribution of HOR catalyst on the performance loss after reverse polarity
  • the performance loss of the HOR catalyst is lower than that of the HOR when the HOR catalyst is distributed in the area near the membrane and the area near the anode diffusion layer.
  • the catalysts are all distributed in the area close to the membrane, which proves that the double-layer design of HOR catalyst is beneficial to reduce the performance loss after reverse polarity.
  • Example 2 Comparing Example 2 with Comparative Example 10, the HOR catalyst in Example 2 was partly formed on the side of the anode near the membrane layer, and partly formed on the side of the anode near the anode diffusion layer; the HOR catalyst provided by Comparative Example 10 was all formed On the side of the anode near the membrane. It can be seen from the data in the table that when the reverse polarity time is the same as 90 minutes, the performance loss of the membrane electrode provided in Example 2 after reverse polarity is smaller. It shows that the HOR catalyst is distributed in the area close to the membrane and the area close to the anode diffusion layer, which can significantly reduce the carbon corrosion and performance loss after the reverse electrode while ensuring the initial performance.
  • the reverse electrode mainly occurs on the anode side of the membrane electrode.
  • the carbon corrosion is determined by the anode potential, the corrosion resistance of the carbon support, and the water content near the carbon support. The higher the anode potential, the more serious the carbon corrosion, and the introduction of OER catalyst can reduce the anode potential; the higher the corrosion resistance of the carbon support, the slower the carbon corrosion. The closer the carbon support is to the membrane, the more serious it will corrode with water.
  • HOR catalysts are respectively distributed in the area close to the membrane and the area close to the anode diffusion layer. While ensuring the initial performance, it significantly reduces the performance loss after the reverse electrode and prolongs the reverse electrode withstand time.
  • the membrane electrode and the preparation method thereof provided by the embodiments of the present disclosure can not only reduce the performance loss after the reverse polarity, but also prolong the reverse polarity endurance time, so that the performance of the fuel cell is better, and the service life of the fuel cell is prolonged.

Abstract

本申请提供一种膜电极及其制备方法、燃料电池，属于燃料电池技术领域。膜电极包括质子交换膜、阳极催化剂和阳极扩散层。阳极催化剂包括第一催化剂层和第二催化剂层。质子交换膜、第一催化剂层、第二催化剂层和阳极扩散层依次排布。其中，第一催化剂层包括氢氧化催化剂，第二催化剂层包括混合的氢氧化催化剂和水电解催化剂。由于阳极催化剂中的氢氧化催化剂分层分布，可以延长膜电极的反极耐受时间和减小反极后的性能损失。

Description

膜电极及其制备方法、燃料电池 技术领域
本申请涉及燃料电池技术领域，具体而言，涉及一种膜电极及其制备方法、燃料电池。
背景技术
质子交换膜燃料电池(PEMFC，Proton Exchange Membrane Fuel Cell)是一种将氢能转化为电能的装置，其最终排放物仅有水，是清洁绿色无污染的发电装置，在汽车、船舶、轨道交通、固定基站、无人机等领域有广泛的应用前景。质子交换膜燃料电池内部的核心组件称为膜电极(MEA，Membrane Electrode Assemblies)，是其发电的最小组成单元。然而在一些恶劣工况下，膜电极会发生破坏，最终导致燃料电池的失效。燃料电池步入商业化，应该保证其寿命，降低及避免膜电极在恶劣工况下的性能损失。
反极(Cell reversal)是膜电极运行过程中所遭遇的其中一种恶劣工况。具体指：电堆运行过程中单片或者多片膜电极由于阳极堵水或者凝结有冰块时，阳极的氢气传输受阻，无法到达催化剂Pt表面产生质子。为了维持反极前的电流(质子流)，阳极的电位由反极前的0V(相对于标准氢电极，SHE)短时间内攀升至高于1.5V，此时膜电极的电压通常低于-1V；在阳极高电位下，碳组分与水反应，碳发生腐蚀产生质子维持电流。碳不断腐蚀，最终导致膜电极的失效。
在***层面，预防燃料电池的反极主要通过电压巡检传感器来实施。但是这并不能从本质上减少反极引起的性能损失。电压巡检的原理是检测膜电极的电位，如果膜电极电压由正变负，意味着发生反极，及时切断电路。但是当检测到电压变负的情况时，反极已经发生一段时间，性能损失仍不能避免。
反极时，碳发生腐蚀是为了维持质子流(C+2H 2O＝4H ++CO 2+4e -)，只要有其他途径可以替代性维持质子流，碳腐蚀就会被抑制。水电解(OER，2H 2O＝4H ++O 2+4e -)这一途径恰好可以提供质子流，但是水电解通常要求的电压高于2V，高于碳腐蚀的电位；为了降低水电解的电位，有必要引入水电解催化剂以实现在相对较低电位下由水电解途径维持质子流，从而减少甚至避免碳腐蚀，这便是抗反极的原理。
现有的膜电极不能够很好地降低反极后的性能损失，膜电极的抗反极能力不强。
发明内容
本申请的目的在于提供一种膜电极及其制备方法、燃料电池，能够有效降低反极后的性能损失，延长反极耐受时间，增强膜电极的抗反极能力。
本申请实施例提供一种膜电极，包括质子交换膜、阳极催化剂和阳极扩散层。阳极催化剂包括第一催化剂层和第二催化剂层。质子交换膜、第一催化剂层、第二催化剂层和阳极扩散层依次排布。其中，第一催化剂层包括氢氧化催化剂，第二催化剂层包括混合的氢氧化催化剂和水电解催化剂。
在阳极催化剂层的靠近阳极扩散层的一侧具有水电解催化剂，发生反极时，可以减少水电解催化剂处发生碳腐蚀，且水电解催化剂使靠近阳极扩散层的一侧的水发生电解，能够为质子交换膜提供质子流，则可以减少氢氧化催化剂处的碳腐蚀，可以延长反极耐受时间。在阳极催化剂层的靠近质子交换膜的一侧和靠近阳极扩散层的一侧均具有氢氧化催化剂，在具有足够的氢氧化催化剂提供质子流的情况下，由于部分氢氧化催化剂形成在阳极催化剂层的靠近阳极扩散层的一侧，可以进一步减少氢氧化催化剂的碳腐蚀，减小反极后的性能损失，延长反极耐受时间。
附图说明
为了更清楚地说明本公开实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本公开的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1为本申请实施例提供的膜电极的剖面图；
图2为Pt(Ir)质量分数对反极后性能损失的影响；
图3为膜电极过夜恢复对反极后性能损失的影响；
图4为碳载体石墨化对反极耐受时间的影响；
图5为HOR催化剂的分布对模拟反极性能损失的影响；
图6为HOR催化剂的分布对反极后性能损失的影响(实施例1与比较例5)；
图7为HOR催化剂的分布对反极后性能损失的影响(实施例2与比较例10)。
图标：30-膜电极；310-阴极扩散层；320-阴极催化剂层；330-质子交换膜；340-阳极催化剂层；350-阳极扩散层；341-第一催化剂层；342-第二催化剂层。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将对本申请实施例中的技术方案进行清楚、完整地描述。实施例中未注明具体条件者，按照常规条件或制造商建议的条件进行。所用试剂或仪器未注明生产厂商者，均为可以通过市售购买获得的常规产品。
衡量膜电极抗反极能力主要有两个参数，一个是通常的反极耐受时间(cell reversal tolerance)，另一个则是反极后的性能损失(performance loss during cell  reversal)。
为了延长膜电极的反极耐受时间，并减小膜电极反极后的性能损失。本申请中，氢氧化催化剂可以分侧分布。图1为本申请实施例提供的膜电极30的剖面图。请参阅图1，膜电极30包括依次排布的阴极扩散层310、阴极催化剂层320、质子交换膜330、阳极催化剂层340和阳极扩散层350。阳极催化剂层340包括第一催化剂层341和第二催化剂层342，阴极扩散层310、阴极催化剂层320、质子交换膜330、第一催化剂层341、第二催化剂层342和阳极扩散层350依次排布。其中，第一催化剂层341包括氢氧化催化剂，第二催化剂层342包括混合的氢氧化催化剂和水电解催化剂。
若在阳极催化剂层340的靠近质子交换膜330的一侧和靠近阳极扩散层350的一侧均形成氢氧化催化剂，则在具有足够的氢氧化催化剂提供质子流的情况下，由于部分氢氧化催化剂形成在阳极催化剂层340的靠近阳极扩散层350的一侧，可以使部分氢氧化催化剂附近的水含量较少，可以减少氢氧化催化剂的碳腐蚀，减小反极后的性能损失。在阳极催化剂层340的靠近阳极扩散层350的一侧具有水电解催化剂，发生反极时，可以减少水电解催化剂处发生碳腐蚀，且水电解催化剂使靠近阳极扩散层350的一侧的水发生电解，能够为质子交换膜提供质子流，则可以减少氢氧化催化剂处的碳腐蚀，可以延长反极耐受时间。
其中，水电解催化剂包括第一载体和负载于第一载体上的水电解催化剂活性成分。氢氧化催化剂包括第二载体和负载于第二载体上的氢氧化催化剂活性成分。
为了增加阳极载体的耐腐蚀性。保证水电解催化剂的活性成分和氢氧化催化剂的活性成分不脱落，一直发挥水电解催化剂和氢氧化催化剂的作用。所以， 活性成分可以负载在耐腐蚀载体上，阳极载体耐腐蚀性越强，碳腐蚀越慢；碳载体越少，反极后的性能损失越低。
为了增加阳极催化剂的阳极载体的耐腐蚀性能，阳极载体(也就是第一载体和第二载体)可以为导电金属氧化物或石墨碳。石墨碳和导电金属氧化物均为抗高电位(1.5V以上)腐蚀的载体，使用导电金属氧化物或石墨碳作为活性物质的阳极载体，可以延长反极耐受时间。
其中，导电金属氧化物中不含有碳，可以避免碳腐蚀。可选地，导电金属氧化物选自Ti 4O 7、Nb-TiO 2和ITO中的一种。石墨碳可以是石墨化的碳材料，碳经过了石墨化以后，可以减少碳腐蚀。
进一步地，水电解催化剂活性成分可以是RuO 2，IrO 2，Ru xIr 1-xO 2中的一种或多种。例如：水电解催化剂活性成分可以是RuO 2；水电解催化剂活性成分可以是IrO 2；水电解催化剂活性成分可以是Ru xIr 1-xO 2；水电解催化剂活性成分可以是RuO 2和IrO 2的混合物；水电解催化剂活性成分可以是RuO 2和Ru xIr 1-xO 2的混合物；水电解催化剂活性成分可以是IrO 2和Ru xIr 1-xO 2的混合物；水电解催化剂活性成分可以是RuO 2、IrO 2和Ru xIr 1-xO 2的混合物。当然，本申请中，水电解催化剂的活性成分不做限定，只要能够作为水电解催化剂的活性成分均在本申请的保护范围之内。
水电解催化剂可以通过水电解提供质子流，且可以降低水电解的电位，使阳极电位相对较低，减少碳腐蚀，能够在保证反极耐受时间的情况下，减小反极后的性能损失。
水电解催化剂中水电解催化剂活性成分的质量百分数为10％-80％。可选地，水电解催化剂中活性组分的质量百分数为40％-80％。
其中，氢氧化催化剂的活性成分为金属催化剂，包括Pt、Ir、PtIr合金和 Pd中的一种或多种。例如：氢氧化催化剂的活性成分可以为Pt；氢氧化催化剂的活性成分可以为Ir；氢氧化催化剂的活性成分可以为PtIr合金；氢氧化催化剂的活性成分可以为Pd。当然，本申请中，氢氧化催化剂的活性成分不做限定，只要能够作为氢氧化催化剂的活性成分均在本申请的保护范围之内。
氢氧化催化剂中氢氧化催化剂活性成分的质量百分数为10％-80％。可选地，氢氧化催化剂中的Pt的质量百分数为40％-80％。
可选地，第一催化剂层341中的氢氧化催化剂与第二催化剂层342中的氢氧化催化剂的种类可以相同，也可以不同。例如：第一催化剂层341中的氢氧化催化剂的活性成分是Pt，第二催化剂层342中的氢氧化催化剂的活性成分也是Pt；或第一催化剂层341中的氢氧化催化剂的活性成分是Pt，第二催化剂层342中的氢氧化催化剂的活性成分是Ir；或第一催化剂层341中的氢氧化催化剂的活性成分是Ir，第二催化剂层342中的氢氧化催化剂的活性成分是Pt。
可选地，第一催化剂层341中的氢氧化催化剂和第二催化剂层342中的氢氧化催化剂的质量比可以是1:10-1:0.1。进一步地，第一催化剂层341中的氢氧化催化剂和第二催化剂层342中的氢氧化催化剂的质量比可以是1:5-1:0.5。进一步地，第一催化剂层341中的氢氧化催化剂和第二催化剂层342中的氢氧化催化剂的质量比可以是1:2-1:0.8。进一步地，第一催化剂层341中的氢氧化催化剂和第二催化剂层342中的氢氧化催化剂的质量比可以是1:1。
氢氧化催化剂分侧分布时，所得膜电极30的制备方法可以是：将氢氧化催化剂形成于质子交换膜330的阳极侧得到第一催化剂层341，将混合的氢氧化催化剂和水电解催化剂形成于阳极扩散层350得到第二催化剂层342，将第一催化剂层341和第二催化剂层342贴合。或将氢氧化催化剂形成于质子交换膜330的阳极侧得到第一催化剂层341，将混合的氢氧化催化剂和水电解催化 剂形成于第一催化剂层341的背离质子交换膜330的一侧得到第二催化剂层342，将阳极扩散层350形成于第二催化剂层342的背离第一催化剂层341的一侧。可以得到上述膜电极30。
例如：将氢氧化催化剂浆料喷涂于质子交换膜330的阳极侧得到第一催化剂层341，将混合的水电解催化剂和氢氧化催化剂浆料喷涂于阳极扩散层350得到第二催化剂层342，将第一催化剂层341与第二催化剂层342贴合。
通过上述方法得到的膜电极30，既可以延长膜电极的反极耐受时间，又可以减小膜电极反极后的性能损失。使用上述膜电极用来制备燃料电池，燃料电池的性能更佳。
实施例1
膜电极的制备：阴极催化剂为60％Pt/C(科琴黑)，阳极HOR催化剂(氢氧化催化剂)为40％Pt/GrC(石墨化科琴黑)，阳极OER催化剂(水电解催化剂)为40％IrO 2/GrC(石墨化科琴黑，同上，之后不再赘述)。
阴极催化剂为60％Pt/C，阳极HOR催化剂为40％Pt/GrC，分层结构设计，阳极OER催化剂为40％IrO 2/GrC。阴极催化剂中Pt的载量为0.4mg Pt/cm 2，喷涂于CCM(质子交换膜)阴极侧。阳极HOR催化剂中Pt的载量共为0.1mg Pt/cm 2，OER催化剂中IrO 2的载量为0.05mg Ir/cm 2。其中阳极HOR催化剂中的一半(0.05mg Pt/cm 2)喷涂于CCM阳极侧，阳极HOR催化剂中的另一半(0.05mg Pt/cm 2)与阳极OER催化剂(0.05mg Ir/cm 2)混合后喷涂于阳极GDL。
抗反极测试同比较例1。反极结束后，将膜电极放置10h并进行过夜恢复(overnight recovery)，测试反极后的V-I曲线并对比性能的损失。
实施例2
膜电极的制备：阴极催化剂为60％Pt/C，阳极HOR催化剂为70％Pt/GrC，阳极OER催化剂为70％IrO 2/GrC。
阴极催化剂为60％Pt/C，阳极HOR催化剂为70％Pt/GrC，分层结构设计， 阳极OER催化剂为70％IrO 2/GrC。阴极催化剂中Pt的载量为0.4mg Pt/cm 2，喷涂于CCM阴极侧。阳极HOR催化剂中Pt的载量共为0.1mg Pt/cm 2，OER催化剂中IrO 2的载量为0.05mg Ir/cm 2。其中阳极HOR催化剂中的一半(0.05mg Pt/cm 2)喷涂于CCM阳极侧，阳极HOR催化剂中的另一半(0.05mg Pt/cm 2)与阳极OER催化剂(0.05mg Ir/cm 2)混合后喷涂于阳极GDL。
抗反极测试同比较例1，反极结束后，将膜电极放置10h并进行过夜恢复(overnight recovery)，测试反极后的V-I曲线并对比性能的损失。
比较例1
膜电极的制备：阴极催化剂为60％Pt/C，阳极HOR催化剂为40％Pt/GrC，阳极OER催化剂为40％IrO 2/GrC。
阴极催化剂为60％Pt/C，阳极HOR催化剂为40％Pt/GrC，阳极OER催化剂为40％IrO 2/GrC。阴极催化剂中Pt的载量为0.4mg Pt/cm 2，喷涂于CCM阴极侧。阳极HOR催化剂中Pt的载量为0.1mg Pt/cm 2，喷涂于CCM阳极侧，OER催化剂中IrO 2的载量为0.1mg Ir/cm 2，喷涂于阳极扩散层(GDL)。
抗反极测试的条件是：
阳极流量：1slpm，阴极流量：1slpm，测试温度：75℃，相对湿度：阳极100％RH，阴极100％RH，测试压力：常压；
V-I曲线测试结束后，外接0.2A/cm 2或1A/cm 2的电流密度的恒流源，保持H 2/Air状态至电压稳定。然后将阳极H 2切换成N 2，模拟阳极H 2不足导致反极的工况。由于N 2吹扫管路内的H 2需要一些时间，因此实际反极开始时从电压骤降的时刻计算。同时将-1.5V设为保护电压，当电池电压低于-1.5V时，恒流源停止工作，该时刻可以认为反极理论结束时间(自动停止)；若反极耐受时间较长，在某个设定的时间同样可以人为停止恒流源，这是手动停止。无论自动还是手动停止，从反极开始至反极结束的时间为反极耐受时间，在该时间内，是模拟H 2不足的N 2/Air状态。测试反极后的V-I曲线对比性能的损失。
比较例2
阴极催化剂为60％Pt/C，阳极HOR催化剂为70％Pt/GrC，阳极OER催化剂为70％IrO 2/GrC。
膜电极的制备：阴极催化剂为60％Pt/C，阳极HOR催化剂为70％Pt/GrC，阳极OER催化剂为70％IrO 2/GrC。阴极催化剂中Pt的载量为0.4mg Pt/cm 2，喷涂于CCM阴极侧。阳极HOR催化剂中Pt的载量共为0.1mg Pt/cm 2，喷涂于CCM阳极侧，OER催化剂中IrO 2的载量为0.1mg Ir/cm 2，喷涂于阳极GDL。
抗反极测试同比较例1。反极结束后，测试反极后的V-I曲线并对比性能的损失。
比较例3
膜电极的制备：阴极催化剂为60％Pt/C，阳极HOR催化剂为70％Pt/GrC。
阴极催化剂为60％Pt/C，阳极HOR催化剂为70％Pt/GrC，分层结构设计。阴极催化剂中Pt的载量为0.4mg Pt/cm 2，喷涂于CCM阴极侧。阳极HOR催化剂中Pt的载量共为0.1mg Pt/cm 2，其中0.05mg Pt/cm 2喷涂于CCM阳极侧，0.05mg Pt/cm 2喷涂于阳极GDL。
模拟反极测试(阳极老化)的程序如下：
模拟反极测试：阳极流量：0.5slpm，阴极流量：0.5slpm，测试温度：80℃，相对湿度：阳极45％RH，阴极45％RH，测试压力：0.5bar，0.5bar。
V-I曲线测试结束后，将H 2/N 2气氛切换为N 2/H 2，外接Arbin，将电压设定为1.6V，时间设定为2小时。模拟阳极反极的工况。模拟反极结束后，将膜电极放置10h并进行过夜恢复(overnight recovery)，测试模拟反极后的V-I曲线并对比性能的损失。
比较例4
HOR催化剂的制备同比较例3。
膜电极的制备：阴极催化剂为60％Pt/C，阳极HOR催化剂为70％Pt/GrC。阴极催化剂中Pt的载量为0.4mg Pt/cm 2，喷涂于CCM阴极侧，阳极HOR催化剂中Pt的载量共为0.1mg Pt/cm 2，喷涂于CCM阳极侧。
模拟反极测试同比较例3，模拟反极结束后，将膜电极放置10h并进行过夜恢复(overnight recovery)，测试模拟反极后的V-I曲线并对比性能的损失。
比较例5
HOR催化剂、OER催化剂及膜电极的制备同比较例1，抗反极测试同样与比较例1相同，反极测试后，将膜电极放置10h并进行过夜恢复(overnight recovery)，然后比较反极前后的性能损失。
比较例6
HOR催化剂、OER催化剂及膜电极的制备同比较例2，抗反极测试同样与比较例1相同，反极测试后，将膜电极放置10h并进行过夜恢复(overnight recovery)，然后比较反极前后的性能损失。
比较例7
HOR催化剂，OER催化剂及膜电极的制备同比较例1，抗反极测试同样与比较例1相同，但反极耐受时间为60min。反极测试后，将膜电极放置10h并进行过夜恢复(overnight recovery)，然后比较反极前后的性能损失。
比较例8
HOR催化剂，OER催化剂及膜电极的制备同比较例2，抗反极测试同样与比较例2相同，但反极耐受时间为60min。反极测试后，将膜电极放置10h并进行过夜恢复(overnight recovery)，然后比较反极前后的性能损失。
比较例9
膜电极的制备：阴极催化剂为60％Pt/C，阳极HOR催化剂为60％Pt/C，阳极OER催化剂为40％IrO 2/C。阴极催化剂中Pt的载量为0.4mg Pt/cm 2，喷涂于CCM阴极侧，阳极HOR催化剂中Pt的载量为0.1mg Pt/cm 2，喷涂于CCM阳极侧，阳极OER催化剂中IrO 2的载量为0.1mg Ir/cm 2，喷涂于阳极GDL。
抗反极测试同实施例1。反极结束后，测试反极后的V-I曲线并对比性能的损失。
比较例10
HOR和OER催化剂的制备同比较例2。
膜电极的制备：阴极催化剂为60％Pt/C，阳极HOR催化剂为70％Pt/GrC，阳极OER催化剂为70％IrO 2/GrC。阴极催化剂中Pt的载量为0.4mg Pt/cm 2，喷涂于CCM阴极侧。阳极HOR催化剂中Pt的载量为0.1mg Pt/cm 2，喷涂于CCM阳极侧。阳极OER催化剂中IrO 2的载量为0.05mg Ir/cm 2，喷涂于阳极GDL。
反极测试同比较例1，反极结束后，将膜电极放置10h并进行过夜恢复(overnight recovery)，测试反极后的V-I曲线并对比性能的损失。
实验例1
对于反极前后的性能损失，这里选取小电流区域(LCD，0.2A/cm 2)的电压损失及大电流区域(HCD，1A/cm 2)的电压损失来综合反映反极前后的性能损失，其中，实施例1-实施例2以及比较例1-比较例10的膜电极组分及测试条件如表1：
表1.不同的膜电极组分及测试条件
Figure PCTCN2019121277-appb-000001
使用表1记载的膜电极及其测试条件进行膜电极的初始性能以反极后的 性能比较得到表2。
表2.不同的膜电极的初始性能及反极后性能损失
Figure PCTCN2019121277-appb-000002
从表2可以看出：
(1)、比较例1与比较例2对比，以及比较例7和比较例8对比，比较例1与比较例2的反极耐受时间均为40min，比较例7和比较例8的反极耐受时间均为60min，在膜电极的阳极催化剂的HOR催化剂和OER催化剂的活性成分的含量都更高，以及反极耐受时间相同的情况下，反极后的性能损失减小。在膜电极的阳极催化剂的HOR催化剂和OER催化剂的活性成分的含量相同的情况下，反极耐受时间越长，反极后的性能损失越多。进一步地，从图2(Pt(Ir)质量分数对反极后性能损失的影响)可以看出，高Pt(Ir)质量分数降低了碳载体的用量，使得更少的碳发生腐蚀，从而降低了反极后的性能损失。
进一步地，从实施例1和实施例2对比可以看出，HOR催化剂分别分布在靠近膜的区域和靠近阳极扩散层的区域时，高Pt(Ir)质量分数降低了碳载体的用量，使得更少的碳发生腐蚀，从而明显延长了反极耐受时间。
(2)、比较例1与比较例5对比、比较例2与比较例6对比可以看出，膜电极过夜放置以后ΔV的值减小。进一步地，从图3(膜电极过夜恢复对反极后性能损失的影响)中也可以看出，过夜恢复以后，反极后的性能损失会减小，说明过夜恢复以后，可以使膜电极的可逆损失部分得以恢复，膜电极的性能损失降低。其原因是：过夜恢复使得膜电极内部温度降低，湿度增加，构筑的三相界面增加，损失的性能得以部分恢复。所以，可以在过夜恢复后对反极后性能损失进行测试，避免将可逆损失计算在反极后的性能损失中，使反极后的性能损失的研究更加精确。
(3)、比较例1与比较例9可以看出，比较例1提供的OER催化剂和HOR催化剂的载体为石墨化的科琴黑GrC，比较例9提供的OER催化剂和HOR催化剂的载体为科琴黑C。比较例1提供的膜电极的反极耐受时间更长，反极后的性能损失更小，说明石墨化的科琴黑的耐腐蚀性能比科琴黑的耐腐蚀性能好。进一步地，从图4(碳载体石墨化对反极耐受时间的影响)可以看出，当碳载体为普通未经石墨化处理的科琴黑时，碳载体腐蚀速率快，较短时间内其承载的Ir组分发生脱落，反极耐受时间难以维持；随着Ir组分的脱落，阳极电位不可避免地升高，更加剧了阳极侧碳载体的腐蚀以及Pt组分的脱落，反极后性能损失较大。当碳载体为石墨化处理的科琴黑时时，其本身腐蚀速率较慢，抑制了Ir组分的脱落，从而避免阳极电位的急剧升高，减缓了阳极侧碳载体的腐蚀及Pt的脱落，最终降低了反极后的性能损失。
(4)、通过模拟阳极老化的测试程序来验证HOR催化剂双层分布对碳腐蚀的影响。从图5(HOR催化剂的分布对模拟反极性能损失的影响)可以看出，当阳极电位设定为1.6V，2h模拟反极时，HOR催化剂分别分布在靠近膜的区域和靠近气体扩散层的区域时的性能损失明显低于HOR催化剂全部分布在靠近膜的区域，这为降低反极后的性能损失提供了思路。
进一步地，实施例1与比较例5对比，在反极耐受时间相同的情况下，HOR催化剂分别分布在靠近膜的区域和靠近阳极扩散层的区域时的性能损失 低于HOR催化剂全部分布在靠近膜的区域，证明HOR催化剂双层设计有利于降低反极后的性能损失。从图6(HOR催化剂的分布对反极后性能损失的影响)可以看出，当反极40min后，HOR催化剂分别分布在靠近膜的区域和靠近阳极扩散层的区域时的性能损失低于HOR催化剂全部分布在靠近膜的区域，证明HOR催化剂双层设计有利于降低反极后的性能损失。
实施例2与比较例10对比，实施例2中的HOR催化剂一部分形成于阳极的靠近膜层的一侧，一部分形成于阳极的靠近阳极扩散层的一侧；比较例10提供的HOR催化剂全部形成在阳极的靠近膜层的一侧。通过表中数据可以看出，在反极时间相同均为90min的情况下，实施例2提供的膜电极的反极后的性能损失更小。说明HOR催化剂分别分布在靠近膜的区域与靠近阳极扩散层的区域，在保证初始性能的同时明显降低碳腐蚀以及反极后的性能损失。
进一步地，从图7(HOR催化剂的分布对反极后性能损失的影响)可以看出，当反极90min后，HOR催化剂分别分布在靠近膜的区域和靠近阳极扩散层的区域时的性能损失明显低于HOR催化剂全部分布在靠近膜的区域，再次证明HOR催化剂双层设计有利于降低反极后的性能损失。
其原因在于：膜电极内由于阴极水比阳极多，阴极的水会反扩散至阳极，因此阳极靠近膜的区域水含量较靠近气体扩散层的区域水含量高。反极主要发生在膜电极的阳极侧，碳腐蚀由阳极电位，碳载体耐腐蚀性，碳载体附近的水含量所共同决定。阳极电位越高，碳腐蚀越严重，OER催化剂的引入可以降低阳极电位；碳载体耐腐蚀性越高，碳腐蚀越慢。碳载体越靠近膜，其与水发生腐蚀的情况越严重，同时产生的质子传输至阴极的距离越短，碳更容易腐蚀。因此碳载体越靠近膜，腐蚀越严重；如果碳载体全部分布在靠近阳极扩散层的区域，由于质子的传质距离显著增加，初始性能降低。为了兼顾初始性能与降低碳腐蚀，HOR催化剂分别分布在靠近膜的区域与靠近阳极扩散层的区域，在保证初始性能的同时明显降低反极后的性能损失，延长反极耐受时间。
以上所描述的实施例是本申请一部分实施例，而不是全部的实施例。本申 请的实施例的详细描述并非旨在限制要求保护的本申请的范围，而是仅仅表示本申请的选定实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
工业实用性
本公开实施例提供的膜电极及其制备方法，既能够减小反极后的性能损失，又能够延长反极耐受时间，使燃料电池的性能更佳，利于延长燃料电池的使用寿命。

Claims (17)

  1. 一种膜电极，包括：
    质子交换膜，
    阳极催化剂层，和
    阳极扩散层，
    所述阳极催化剂层包括第一催化剂层和第二催化剂层，所述质子交换膜、所述第一催化剂层、所述第二催化剂层和所述阳极扩散层依次排布；
    其中，所述第一催化剂层包括氢氧化催化剂，所述第二催化剂层包括混合的氢氧化催化剂和水电解催化剂。
  2. 根据权利要求1所述的膜电极，其中，所述第一催化剂层中的氢氧化催化剂和所述第二催化剂层中的氢氧化催化剂的质量比1:10-1:0.1。
  3. 根据权利要求2所述的膜电极，其中，所述第一催化剂层中的氢氧化催化剂和所述第二催化剂层中的氢氧化催化剂的质量比1:5-1:0.5。
  4. 根据权利要求1所述的膜电极，其中，所述水电解催化剂包括第一载体和负载于所述第一载体上的水电解催化剂活性成分。
  5. 根据权利要求4所述的膜电极，其中，所述水电解催化剂活性成分包括RuO 2、IrO 2和Ru xIr 1-xO 2中的一种或多种。
  6. 根据权利要求4所述的膜电极，其中，所述第一载体选自石墨碳，Ti 4O 7，Nb-TiO 2，ITO中的一种。
  7. 根据权利要求4所述的膜电极，其中，所述水电解催化剂中所述水电解催化剂活性成分的质量百分数为10％-80％。
  8. 根据权利要求7所述的膜电极，其中，所述水电解催化剂中所述水电解催化剂活性成分的质量百分数为40％-80％。
  9. 根据权利要求1所述的膜电极，其中，所述氢氧化催化剂包括第二载体及负载在所述第二载体上的氢氧化催化剂活性成分。
  10. 根据权利要求9所述的膜电极，其中，所述氢氧化催化剂活性成分包 括Pt、Ir、PtIr合金和Pd中的一种或多种。
  11. 根据权利要求9所述的膜电极，其中，所述第二载体选自石墨碳，Ti 4O 7，Nb-TiO 2，ITO中的一种。
  12. 根据权利要求9所述的膜电极，其中，所述氢氧化催化剂中氢氧化催化剂活性成分的质量百分数为10％-80％。
  13. 根据权利要求12所述的膜电极，其中，所述氢氧化催化剂中氢氧化催化剂活性成分的质量百分数为40％-80％。
  14. 一种燃料电池，包括权利要求1-13任一项所述的膜电极。
  15. 一种权利要求1-13任一项所述的膜电极的制备方法，其中，将所述氢氧化催化剂形成于所述质子交换膜的阳极侧得到所述第一催化剂层，将混合的所述氢氧化催化剂和所述水电解催化剂形成于所述阳极扩散层得到所述第二催化剂层，将所述第一催化剂层和所述第二催化剂层贴合；
    或将所述氢氧化催化剂形成于所述质子交换膜的阳极侧得到第一催化剂层，将混合的所述氢氧化催化剂和所述水电解催化剂形成于所述第一催化剂层的背离所述质子交换膜的一侧得到第二催化剂层，将所述阳极扩散层形成于所述第二催化剂层的背离所述第一催化剂层的一侧。
  16. 根据权利要求15所述的膜电极的制备方法，其中，调配所述第一催化剂层中的氢氧化催化剂和所述第二催化剂层中的氢氧化催化剂的质量比1:10-1:0.1。
  17. 根据权利要求16所述的膜电极的制备方法，其中，调配所述第一催化剂层中的氢氧化催化剂和所述第二催化剂层中的氢氧化催化剂的质量比1:5-1:0.5。
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008027647A (ja) * 2006-07-19 2008-02-07 Toyota Motor Corp 燃料電池用燃料極およびそれを備えた燃料電池
CN101421869A (zh) * 2006-04-14 2009-04-29 丰田自动车株式会社 燃料电池
CA2934237A1 (en) * 2016-06-28 2016-08-31 Daimler Ag Anode for improved reversal tolerance in fuel cell stack
CN107004862A (zh) * 2014-12-15 2017-08-01 3M创新有限公司 膜电极组件
US20170309924A1 (en) * 2011-07-18 2017-10-26 Daimler Ag Solid polymer electrolyte fuel cell with improved voltage reversal tolerance
CN108063267A (zh) * 2017-12-26 2018-05-22 新源动力股份有限公司 一种燃料电池的具有多层结构的催化层及其制备方法
CN109417180A (zh) * 2016-12-29 2019-03-01 可隆工业株式会社 膜电极组件及其制备方法和包括该膜电极组件的燃料电池
CN109792066A (zh) * 2016-09-08 2019-05-21 戴姆勒股份公司 用于燃料电池***的在冰点以下启动的方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101421869A (zh) * 2006-04-14 2009-04-29 丰田自动车株式会社 燃料电池
JP2008027647A (ja) * 2006-07-19 2008-02-07 Toyota Motor Corp 燃料電池用燃料極およびそれを備えた燃料電池
US20170309924A1 (en) * 2011-07-18 2017-10-26 Daimler Ag Solid polymer electrolyte fuel cell with improved voltage reversal tolerance
CN107004862A (zh) * 2014-12-15 2017-08-01 3M创新有限公司 膜电极组件
CA2934237A1 (en) * 2016-06-28 2016-08-31 Daimler Ag Anode for improved reversal tolerance in fuel cell stack
CN109792066A (zh) * 2016-09-08 2019-05-21 戴姆勒股份公司 用于燃料电池***的在冰点以下启动的方法
CN109417180A (zh) * 2016-12-29 2019-03-01 可隆工业株式会社 膜电极组件及其制备方法和包括该膜电极组件的燃料电池
CN108063267A (zh) * 2017-12-26 2018-05-22 新源动力股份有限公司 一种燃料电池的具有多层结构的催化层及其制备方法

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