A membrane electrode, a fuel cell and a method for manufacturing the same
By optimizing the catalyst loading and area ratio at the inlet and outlet of the membrane electrode and adopting a distributed spraying process, the problems of poor hydrogen production performance and low water utilization rate of PEM hydrogen production membrane electrode were solved, and the hydrogen production performance and water utilization efficiency were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI ELECTRICGROUP CORP
- Filing Date
- 2023-12-13
- Publication Date
- 2026-06-05
Smart Images
Figure CN117497812B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a membrane electrode, a fuel cell, and a method for preparing the same. Background Technology
[0002] In a proton exchange membrane hydrogen production device, the membrane electrode assembly (MEA) is the core component, serving as the primary site for electrochemical reactions. It facilitates the initiation of reactions, the transport of products, the transfer of electrons, and the transfer of energy. Its fabrication process directly determines the overall power density, lifespan, and cost control of the battery.
[0003] In the preparation of membrane electrodes, a one-time spraying process is generally adopted. Although this process is convenient to operate, in the PEM hydrogen production process, the water flow at the inlet is too fast and the water residence time is too short. If the reaction is too fast, it is easy to cause water shortage in the PEM membrane electrode, which affects the hydrogen production performance and purity. At the outlet, water accumulation is easy to cause flow channel blockage, which affects the hydrogen production performance. Summary of the Invention
[0004] The technical problem solved by this invention is to overcome the shortcomings of existing PEM hydrogen production membrane electrodes, such as poor hydrogen production performance and low water utilization rate, and to provide a membrane electrode, a fuel cell, and a method for their preparation. The membrane electrode of this invention can not only improve hydrogen production performance but also improve water utilization efficiency.
[0005] The present invention solves the above-mentioned technical problems through the following technical solutions:
[0006] The present invention provides a membrane electrode comprising a first gas diffusion layer, a cathode catalyst layer, a proton exchange membrane, an anode catalyst layer, and a second gas diffusion layer connected in sequence.
[0007] Along the main flow direction of the influent water, the cathode catalyst layer sequentially includes a first influent region, a transition region 1, and a first effluent region. The loading of catalyst A in the first influent region is (0.08-0.18) mg / cm³. 2 The loading of catalyst A in the first effluent region is (0.12-0.25) mg / cm³. 2 The loading of catalyst A in the first inlet region is (0.04-0.12) mg / cm³ lower than that in the first outlet region. 2 The area of the first water inlet region accounts for 30%-40% of the total area of the cathode catalyst layer, and the area of the first water outlet region accounts for 30%-40% of the total area of the cathode catalyst layer.
[0008] Along the main flow direction of the influent, the anode catalyst layer sequentially includes a second influent region, a transition region 2, and a second effluent region; the loading of catalyst B in the second influent region is (1.0-1.9) mg / cm³. 2 The loading of catalyst B in the second effluent region is (1.6-2.2) mg / cm³. 2 The catalyst loading in the second inlet region is (0.2-1.0) mg / cm³ lower than that in the second outlet region. 2 The area of the second water inlet region accounts for 30%-40% of the total area of the anode catalyst layer, and the area of the second water outlet region accounts for 30%-40% of the total area of the anode catalyst layer.
[0009] In this invention, according to conventional art, the inlet end is located at the inlet side of the membrane electrode, and the outlet end is located at the outlet side of the membrane electrode.
[0010] In this invention, preferably, the area of the first water inlet region in the cathode catalyst layer accounts for 35%-40% of the total area of the cathode catalyst layer, for example, 35% or 40%.
[0011] In this invention, preferably, the area of the transition region 1 in the cathode catalyst layer accounts for 20%-30% of the total area of the cathode catalyst layer, for example, 25% or 30%.
[0012] In this invention, preferably, the area of the first water outlet region in the cathode catalyst layer accounts for 32%-38% of the total area of the cathode catalyst layer, for example, 35%.
[0013] In this invention, the sum of the area ratios of the first water inlet region, the transition region 1, and the first water outlet region in the cathode catalyst layer is 100%.
[0014] In this invention, preferably, the area of the second water inlet region in the anode catalyst layer accounts for 35%-40% of the total area of the anode catalyst layer, for example, 35% or 40%.
[0015] In this invention, preferably, the area of the transition region 2 in the anode catalyst layer accounts for 20%-30% of the total area of the anode catalyst layer, for example, 25% or 30%.
[0016] In this invention, preferably, the area of the second water outlet region in the anode catalyst layer accounts for 32%-38% of the total area of the anode catalyst layer, for example, 35%.
[0017] In this invention, the sum of the area ratios of the second water inlet region, the transition region 2, and the second water outlet region in the anode catalyst layer is 100%.
[0018] In this invention, the loading of catalyst A or catalyst B refers to the mass of catalyst contained per unit area of the cathode catalyst layer or the anode catalyst layer.
[0019] In this invention, the loading of catalyst A in the first inlet region can be 0.09 mg / cm³. 2 Or 0.16 mg / cm 2 The preferred concentration is (0.15-0.18) mg / cm³. 2 .
[0020] In this invention, the loading of catalyst A in the first outlet region can be 0.16 mg / cm³. 2 Or 0.25 mg / cm 2 The preferred concentration is (0.20-0.25) mg / cm³. 2 .
[0021] In this invention, the loading of catalyst A in the first inlet region is, for example, 0.07 mg / cm³ lower than the loading of catalyst A in the first outlet region. 2 Or 0.09 mg / cm 2 Preferably, it is lower than (0.08-0.12) mg / cm³. 2 .
[0022] In this invention, the loading of catalyst A in the transition zone 1 is preferably located between the loadings of catalyst A in the first inlet region and the first outlet region, more preferably (0.10-0.21) mg / cm³. 2 For example, 0.125 mg / cm 2 Or 0.2 mg / cm 2 .
[0023] In this invention, the loading of catalyst B in the second inlet region can be 1.1 mg / cm³. 2 Or 1.82 mg / cm 2 The preferred concentration is (1.5-1.9) mg / cm³. 2 .
[0024] In this invention, the loading of catalyst B in the second outlet region can be 1.8 mg / cm³. 2 Or 2.1 mg / cm 2 The preferred concentration is (1.9-2.2) mg / cm³. 2 .
[0025] In this invention, the loading of catalyst B in the second inlet region is, for example, 0.28 or 0.7 lower than the loading of catalyst B in the second outlet region, preferably (0.2-0.4) mg / cm³. 2 .
[0026] In this invention, the catalyst B loading in the transition zone 2 is preferably located between the catalyst B loading in the second inlet region and the second outlet region, more preferably (1.3-2.0) mg / cm³. 2 For example, 1.45 mg / cm 2 Or 1.96 mg / cm 2 .
[0027] In this invention, catalyst A can be conventional in the art, such as a platinum-carbon catalyst.
[0028] The platinum-carbon catalyst can be conventional in the art, and the mass fraction of Pt in the platinum-carbon catalyst can be 5% to 60%.
[0029] In this invention, the catalyst B can be conventional in the art, such as an iridium oxide catalyst.
[0030] The purity of the iridium oxide catalyst is not less than 95%.
[0031] In this invention, the raw material for the transition region 1 can be a conventional cathode catalyst layer material in the art.
[0032] In this invention, the raw materials for the first water inlet region, the transition region 1, and the first water outlet region preferably each include catalyst A, ethanol, a saturated monohydric alcohol with 3 carbon atoms, and a Nafion membrane solution.
[0033] In the first water inlet region, the mass ratio of the catalyst A, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is preferably (163-180):(8-9.5):(80-83):1, for example, 170:9.15:82.4:1 or 179:9.15:82.4:1.
[0034] In the transition zone 1, the mass ratio of catalyst A, ethanol, saturated monohydric alcohol with 3 carbon atoms, and Nafion membrane solution is preferably (167.5-182.8):(8-9.5):(80-83):1, for example 174.5:9.15:82.4:1 or 181.9:9.15:82.4:1.
[0035] In the first water outlet region, the mass ratio of the catalyst A, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is preferably (172-186.6):(8-9.5):(80-83):1, for example, 179:9.15:82.4:1 or 186:9.15:82.4:1.
[0036] In this invention, the raw material for the transition zone 2 can be a conventional anode catalyst layer in the art.
[0037] In this invention, the raw materials for the second water inlet region, the transition region 2, and the second water outlet region preferably each include catalyst B, ethanol, a saturated monohydric alcohol with 3 carbon atoms, and a Nafion membrane solution.
[0038] In the second water inlet region, the mass ratio of the catalyst B, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is preferably (149.2-153):(7-8.4):(67.9-69):1, for example, 149.4:7.6:69:1 or 152.5:7.6:69:1.
[0039] In the transition zone 2, the mass ratio of the catalyst B, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is preferably (150.6-154.3):(7-8.4):(67.9-69):1, for example, 150.7:7.6:69:1 or 154.25:7.6:69:1.
[0040] In the second water outlet region, the mass ratio of the catalyst B, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is preferably (152-156.9):(7-8.6):(68.1-69.5):1, for example, 152:7.6:69:1 or 156:7.6:69:1.
[0041] In one specific embodiment, the loading of catalyst A in the first water inlet region of the cathode catalyst layer is 0.09 mg / cm³. 2 The loading of catalyst A in the first effluent region is 0.16 mg / cm³. 2 ;
[0042] In the anode catalyst layer, the loading of catalyst B in the second inlet region is 1.1 mg / cm³. 2 The loading of catalyst B in the second outlet region is 1.8 mg / cm³. 2 .
[0043] In a preferred embodiment, the loading of catalyst A in the first water inlet region of the cathode catalyst layer is 0.09 mg / cm³. 2 The loading of catalyst A in transition region 1 is 0.125 mg / cm³. 2 The loading of catalyst A in the first effluent region is 0.16 mg / cm³. 2 ;
[0044] In the anode catalyst layer, the loading of catalyst B in the second inlet region is 1.1 mg / cm³. 2 The catalyst B loading in transition region 2 is 1.45 mg / cm³. 2 The loading of catalyst B in the second outlet region is 1.8 mg / cm³. 2 .
[0045] In a preferred embodiment, the loading of catalyst A in the first water inlet region of the cathode catalyst layer is 0.09 mg / cm³. 2 The loading of catalyst A in transition region 1 is 0.125 mg / cm³. 2 The loading of catalyst A in the first effluent region is 0.16 mg / cm³. 2 The percentages of the area of the first water inlet region, the area of the transition region 1, and the area of the first water outlet region relative to the total area of the cathode catalyst layer are 40%, 25%, and 35%, respectively.
[0046] In the anode catalyst layer, the loading of catalyst B in the second inlet region is 1.1 mg / cm³. 2 The catalyst B loading in transition region 2 is 1.45 mg / cm³. 2 The loading of catalyst B in the second outlet region is 1.8 mg / cm³. 2 The percentages of the area of the second water inlet region, the area of the transition region 2, and the area of the second water outlet region relative to the total area of the anode catalyst layer are 40%, 25%, and 35%, respectively.
[0047] In one specific embodiment, the loading of catalyst A in the first water inlet region of the cathode catalyst layer is 0.16 mg / cm³. 2 The loading of catalyst A in the first effluent region is 0.25 mg / cm³. 2 ;
[0048] In the anode catalyst layer, the loading of catalyst B in the second inlet region is 1.82 mg / cm³. 2 The loading of catalyst B in the second outlet region is 2.1 mg / cm³. 2 .
[0049] In a preferred embodiment, the loading of catalyst A in the first water inlet region of the cathode catalyst layer is 0.16 mg / cm³. 2 The loading of catalyst A in transition region 1 is 0.2 mg / cm³. 2 The loading of catalyst A in the first effluent region is 0.25 mg / cm³. 2 ;
[0050] In the anode catalyst layer, the loading of catalyst B in the second inlet region is 1.82 mg / cm³. 2 The catalyst B loading in transition region 2 is 1.96 mg / cm³. 2 The loading of catalyst B in the second outlet region is 2.1 mg / cm³. 2 .
[0051] In a preferred embodiment, the loading of catalyst A in the first water inlet region of the cathode catalyst layer is 0.16 mg / cm³. 2 The loading of catalyst A in transition region 1 is 0.2 mg / cm³. 2 The loading of catalyst A in the first effluent region is 0.25 mg / cm³. 2 The percentages of the area of the first water inlet region, the area of the transition region 1, and the area of the first water outlet region relative to the total area of the cathode catalyst layer are 35%, 30%, and 35%, respectively.
[0052] In the anode catalyst layer, the loading of catalyst B in the second inlet region is 1.82 mg / cm³. 2 The catalyst B loading in transition region 2 is 1.96 mg / cm³. 2 The loading of catalyst B in the second outlet region is 2.1 mg / cm³. 2 The percentages of the area of the second water inlet region, the area of the transition region 2, and the area of the second water outlet region relative to the total area of the anode catalyst layer are 35%, 30%, and 35%, respectively.
[0053] In this invention, the Nafion membrane solution can be a conventional perfluorosulfonic acid resin solution in the art.
[0054] In this invention, the solvent in the Nafion membrane solution can be a solution conventional in the art for dissolving perfluorosulfonic acid resins, preferably water and / or an alcohol solvent, and the alcohol solvent is more preferably ethanol.
[0055] In this invention, the solid content of the Nafion membrane solution can be 5%-25%. The solid content generally refers to the percentage by mass of the portion remaining after drying the emulsion or slurry relative to the total mass before drying.
[0056] In this invention, the saturated monohydric alcohol having 3 carbon atoms is preferably isopropanol and / or n-propanol.
[0057] In this invention, the I1 / C1 ratio in the cathode catalyst layer can be 0.5-1, for example 0.6 or 0.8. The I1 / C1 ratio refers to the mass ratio of perfluorosulfonic acid resin in the Nafion membrane solution in the cathode catalyst layer to the non-precious metal in the catalyst A.
[0058] In this invention, the I2 / C2 ratio in the anode catalyst layer can be 0.1-2, for example 0.4 or 0.5. The I2 / C2 ratio refers to the mass ratio of perfluorosulfonic acid resin in the Nafion membrane solution in the anode catalyst layer to the non-precious metal in the catalyst B.
[0059] The present invention also provides a method for preparing the membrane electrode as described above, which includes the following steps:
[0060] (1) The raw materials of the first water inlet region, the raw materials of the transition zone 1, the raw materials of the first water outlet region, the raw materials of the second water inlet region, the raw materials of the transition zone 2 and the raw materials of the second water outlet region are mixed to obtain the first water inlet region slurry, the transition zone 1 slurry, the first water outlet region slurry, the second water inlet region slurry, the transition zone 2 slurry and the second water outlet region slurry respectively.
[0061] (2) The slurry of the first inlet region is coated on one side of the proton exchange membrane, and the slurry of the second inlet region is coated on the other side of the proton exchange membrane;
[0062] (3) The transition region 1 slurry is coated on one side of the proton exchange membrane, and the transition region 2 slurry is coated on the other side of the proton exchange membrane;
[0063] (4) The slurry of the first effluent end region is coated on one side of the proton exchange membrane, and the slurry of the second effluent end region is coated on the other side of the proton exchange membrane;
[0064] (5) The cathode catalyst layer and the anode catalyst layer are obtained by the coating process; the first gas diffusion layer and the second gas diffusion layer are respectively disposed on the surface of the cathode catalyst layer and the anode catalyst layer.
[0065] In steps (2) to (4), the coating method can be conventional in the art, such as ultrasonic spraying.
[0066] In steps (2) to (4), the slurry is preferably dispersed before the coating.
[0067] The dispersion method can be conventional in the art, such as ultrasound and / or homogenization.
[0068] The ultrasound is typically performed in an ultrasonic cleaner. The temperature of the ultrasound can be 8-30°C, for example, 10°C. The duration of the ultrasound can be 10-30 minutes, for example, 15 minutes.
[0069] The homogenization is generally carried out in a homogenizer. The homogenization temperature can be 8-30℃, for example 10℃. The homogenization time can be 5-30 minutes, for example 5 minutes.
[0070] In one specific embodiment, the dispersion method is as follows: first, ultrasonication at 10°C for 15 minutes, followed by homogenization at 10°C for 5 minutes.
[0071] The present invention also provides a fuel cell comprising a membrane electrode assembly as described above.
[0072] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.
[0073] The reagents and raw materials used in this invention are all commercially available.
[0074] The positive and progressive effects of this invention are as follows:
[0075] (1) The membrane electrode of the present invention can improve not only hydrogen production performance but also water utilization efficiency by controlling the amount of catalyst at the inlet and outlet ends.
[0076] (2) The present invention improves the hydrogen production performance of PEM hydrogen production membrane electrode by using a distributed spraying process in different areas of the PEM membrane and adjusting the proportion of proton exchange membrane solution in each spraying step. Compared with the existing one-time spraying process, it effectively improves the hydrogen production efficiency and water utilization efficiency. Attached Figure Description
[0077] Figure 1 This is a cross-sectional view of the cathode catalyst layer or anode catalyst layer in the membrane electrode prepared in Examples 1-2 of the present invention along the direction of the influent water flow.
[0078] Figure 2 This is a schematic diagram of the structure of the membrane electrode prepared in Examples 1-2 of the present invention.
[0079] Figure Labels
[0080] Inlet area 1
[0081] Transition Zone 2
[0082] Water outlet area 3
[0083] First gas diffusion layer 4
[0084] Cathode catalyst 5
[0085] Proton exchange membrane 6
[0086] Anode catalyst layer 7
[0087] Second gas diffusion layer 8 Detailed Implementation
[0088] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.
[0089] The reagent information used in the following examples and comparative examples is as follows:
[0090] The platinum-carbon catalyst was purchased from Tanaka, the yttrium oxide catalyst from CAS Innovation, and the Nafion membrane solution from Chemours. All the above reagents were electronically pure. The spraying equipment was a Sonotek system, and the proton exchange membrane used was prepared from the Nafion membrane solution according to conventional preparation methods in the field.
[0091] In Examples 1-2, I1 / C1 refers to the mass ratio of perfluorosulfonic acid resin in the Nafion membrane solution and non-precious metal elements other than platinum in the platinum-carbon catalyst in the cathode catalyst layer; I2 / C2 refers to the mass ratio of perfluorosulfonic acid resin in the Nafion membrane solution and non-precious metal elements other than iridium in the iridium oxide catalyst in the anode catalyst layer.
[0092] Example 1
[0093] I. Slurry Preparation
[0094] (1) Weigh the cathode catalyst powder and the anode catalyst powder separately using a weighing balance, and seal them for later use.
[0095] (2) Pour the weighed catalyst powder into a beaker, and then use a pipette to transfer ethanol, isopropanol and Nafion membrane solution.
[0096] In the cathode catalyst layer, the mass ratio of each raw material in the slurry at the inlet end is: platinum-carbon catalyst: ethanol: isopropanol: Nafion membrane solution = 170:9.15:82.4:1; the loading of platinum-carbon catalyst at the inlet end is 0.09 mg / cm³. 2 The mass ratio of each raw material in the effluent slurry is: platinum-carbon catalyst: ethanol: isopropanol: Nafion membrane solution = 179:9.15:82.4:1; the loading of platinum-carbon catalyst at the effluent end is 0.16 mg / cm³. 2The mass ratio of each raw material in the transition zone slurry is: platinum-carbon catalyst: ethanol: isopropanol: Nafion membrane solution = 174.5: 9.15: 82.4: 1; the loading of platinum-carbon catalyst in the transition zone is 0.125 mg / cm³. 2 The I1 / Cl ratio in the cathode catalyst layer is 0.6.
[0097] In the anode catalyst layer, the mass ratio of each raw material in the slurry at the inlet end is: iridium oxide catalyst: ethanol: isopropanol: Nafion membrane solution = 149.4:7.6:69:1; the loading of iridium oxide catalyst at the inlet end is 1.1 mg / cm³. 2 The mass ratio of each raw material in the effluent slurry is: iridium oxide catalyst: ethanol: isopropanol: Nafion membrane solution = 152:7.6:69:1; the iridium oxide catalyst loading at the effluent end is 1.8 mg / cm³. 2 The mass ratio of each raw material in the transition zone slurry is: iridium oxide catalyst: ethanol: isopropanol: Nafion membrane solution = 150.7:7.6:69:1; the loading of iridium oxide catalyst in the transition zone is 1.45 mg / cm³. 2 The I2 / C2 ratio in the anode catalyst layer is 0.5.
[0098] (3) Place the raw materials at the inlet of the cathode catalyst layer, the raw materials at the transition zone, the raw materials at the outlet of the cathode catalyst layer, the raw materials at the inlet of the anode catalyst layer, the raw materials at the transition zone, and the raw materials at the outlet of the anode catalyst layer into an ultrasonic cleaner and sonicate them (10℃, 15min) to pretreat the catalyst slurry, and then use a homogenizer to fully disperse it (10℃, 10kPsi, 5min).
[0099] II. Catalyst slurry spraying at the water inlet end
[0100] After setting the spraying parameters, spray the slurry from the anode and cathode inlet ends onto the proton exchange membrane. Increase the loading capacity by increasing the number of localized spraying passes; the specific operation is as follows:
[0101] (1) Turn on the power of the spraying equipment, turn on the N2 valve switch, the exhaust system and the rotating heating table, and set the heating table temperature to 150℃;
[0102] (2) Open the USIPrism software;
[0103] (3) The ultrasonic nozzle completes the home process;
[0104] (4) Place the pretreated PEM film at the spraying position;
[0105] (5) Take out the syringe and pour the prepared slurry into the syringe to fill it;
[0106] (6) Fill the entire pipeline with slurry and turn on the pump's automatic control mode;
[0107] (7) Select the desired spraying menu and modify the number of spraying repetitions according to the installed slurry;
[0108] (8) Turn on the automatic spraying mode. After the equipment completes the spraying according to the set number of spraying times, the nozzle returns to the initial position.
[0109] (9) After spraying is completed, the slurry in the pipeline is recycled into the syringe, the remaining slurry is poured out, and a certain amount of alcohol is added to clean the nozzle.
[0110] III. Catalyst slurry spraying in the transition zone
[0111] After setting the spraying parameters, the slurry for the anode-cathode transition zone is sprayed onto the proton exchange membrane, and then dried after spraying.
[0112] IV. Catalyst slurry spraying at the water outlet
[0113] After setting the spraying parameters, the slurry from the anode and cathode outlets was sprayed onto the proton exchange membrane, and then dried after spraying.
[0114] V. Assembling the membrane electrode
[0115] The proton exchange membrane and gas diffusion layer coated with the catalyst layer are assembled into a membrane electrode.
[0116] Along the main flow direction of the influent, in the cathode catalyst layer, the percentages of the influent end region, transition region, and outlet end region in the total area of the cathode catalyst layer are 40%, 25%, and 35%, respectively; in the anode catalyst layer, the percentages of the influent end region, transition region, and outlet end region in the total area of the anode catalyst layer are 40%, 25%, and 35%, respectively.
[0117] Example 2
[0118] Except for the material information of the following anode and cathode catalyst layers, all other operations and conditions are the same as in Example 1:
[0119] In the cathode catalyst layer, the mass ratio of each raw material in the slurry at the inlet end is: platinum-carbon catalyst: ethanol: isopropanol: Nafion membrane solution = 179:9.15:82.4:1; the loading of platinum-carbon catalyst at the inlet end is 0.16 mg / cm³. 2 The mass ratio of each raw material in the effluent slurry is: platinum-carbon catalyst: ethanol: isopropanol: Nafion membrane solution = 186:9.15:82.4:1; the loading of platinum-carbon catalyst at the effluent end is 0.25 mg / cm³. 2The mass ratio of each raw material in the transition zone slurry is: platinum-carbon catalyst: ethanol: isopropanol: Nafion membrane solution = 181.9:9.15:82.4:1; the loading of platinum-carbon catalyst in the transition zone is 0.2 mg / cm³. 2 The I1 / Cl ratio in the cathode catalyst layer is 0.8.
[0120] In the anode catalyst layer, the mass ratio of each raw material in the slurry at the inlet end is: iridium oxide catalyst: ethanol: isopropanol: Nafion membrane solution = 152.5: 7.6: 69: 1; the loading of iridium oxide catalyst at the inlet end is 1.82 mg / cm³. 2 The mass ratio of each raw material in the effluent slurry is: iridium oxide catalyst: ethanol: isopropanol: Nafion membrane solution = 156:7.6:69:1; the iridium oxide catalyst loading at the effluent end is 2.1 mg / cm³. 2 The mass ratio of each raw material in the transition zone slurry is: iridium oxide catalyst: ethanol: isopropanol: Nafion membrane solution = 154.25: 7.6: 69: 1; the loading of iridium oxide catalyst in the transition zone is 1.96 mg / cm³. 2 The I2 / C2 ratio in the anode catalyst layer is 0.4.
[0121] Along the main flow direction of the influent, in the cathode catalyst layer, the percentages of the influent end region, transition region, and outlet end region in the total area of the cathode catalyst layer are 35%, 30%, and 35%, respectively; in the anode catalyst layer, the percentages of the influent end region, transition region, and outlet end region in the total area of the anode catalyst layer are 35%, 30%, and 35%, respectively.
[0122] Comparative Example 1
[0123] (1) Prepare the anode and cathode catalyst slurries separately:
[0124] The mass ratio of each raw material in the anode catalyst slurry is: iridium oxide catalyst: ethanol: isopropanol: Nafion membrane solution = 149.4:7.6:69:1; the loading of platinum-carbon catalyst is 1.1 mg / cm³. 2
[0125] The mass ratio of each raw material in the cathode catalyst slurry is: iridium oxide catalyst: ethanol: isopropanol: Nafion membrane solution = 170:9.15:82.4:1; the loading of platinum-carbon catalyst is 0.09 mg / cm³. 2 ;
[0126] (2) Place the above-mentioned anode and cathode catalyst slurries in an ultrasonic cleaner and sonicate (10℃, 15min) to pretreat the catalyst slurry, and then use a homogenizer to fully disperse it (10℃, 10kPsi, 5min).
[0127] (3) The anode and cathode slurries are sprayed onto the proton exchange membrane and then assembled with the gas diffusion layer to form a membrane electrode.
[0128] Effect Example
[0129] (1) Figure 1 This is a cross-sectional view of the cathode catalyst layer or anode catalyst layer in the membrane electrode prepared in Examples 1-2 of the present invention along the direction of the influent water flow. Along the main flow direction of the influent water, the cathode catalyst layer or anode catalyst layer sequentially includes an influent end region 1, a transition region 2, and an effluent end region 3.
[0130] Figure 2 This is a schematic diagram of the structure of the membrane electrode prepared in Examples 1-2 of the present invention, which includes a first gas diffusion layer 4, a cathode catalyst layer 5, a proton exchange membrane 6, an anode catalyst layer 7, and a second gas diffusion layer 8 connected in sequence.
[0131] (2) The membrane electrodes of Example 1 and Comparative Example 1 were hot-pressed and sealed, and then assembled into a PEM hydrogen production device for hydrogen production performance testing.
[0132] First, the PEMWE membrane electrode is assembled in the electrolyzer (22cm). 2 (5 N / m), followed by performance activation experiments. The activation experiment mainly adopted the voltage cycling method, controlling the output voltage between 1.4V and 2.4V at a rate of 10mV / sec until the performance of the membrane electrode was not significantly changed. The activation temperature was 60℃. After activation, the current was controlled at 1A / cm. 2 The resistance was tested using a fixed-frequency resistor tester, and the test results are shown in Table 1.
[0133] Table 1
[0134] Example 1 Example 2 Comparative Example 1 resistance value 15mΩ 5mΩ 134mΩ
[0135] According to the data in Table 1, the resistance of the membrane electrodes prepared in Examples 1-2 is much lower than that in Comparative Example 1. The smaller the reaction resistance, the better the hydrogen production performance.
Claims
1. A membrane electrode, characterized in that, It includes a first gas diffusion layer, a cathode catalyst layer, a proton exchange membrane, an anode catalyst layer, and a second gas diffusion layer connected in sequence. Along the main flow direction of the influent water, the cathode catalyst layer sequentially includes a first influent region, a transition region 1, and a first effluent region. The loading of catalyst A in the first influent region is (0.08-0.18) mg / cm³. 2 The loading of catalyst A in the first effluent region is (0.12-0.25) mg / cm³. 2 The loading of catalyst A in the first inlet region is (0.04-0.12) mg / cm³ lower than that in the first outlet region. 2 The area of the first water inlet region accounts for 30%-40% of the total area of the cathode catalyst layer, and the area of the first water outlet region accounts for 30%-40% of the total area of the cathode catalyst layer. Along the main flow direction of the influent, the anode catalyst layer sequentially includes a second influent region, a transition region 2, and a second effluent region; the loading of catalyst B in the second influent region is (1.0-1.9) mg / cm³. 2 The loading of catalyst B in the second effluent region is (1.6-2.2) mg / cm³. 2 The catalyst loading in the second inlet region is (0.2-1.0) mg / cm³ lower than that in the second outlet region. 2 The area of the second water inlet region accounts for 30%-40% of the total area of the anode catalyst layer, and the area of the second water outlet region accounts for 30%-40% of the total area of the anode catalyst layer.
2. The membrane electrode as described in claim 1, characterized in that, The membrane electrode satisfies one or more of the following conditions: (1) In the cathode catalyst layer, the area of the first water inlet region accounts for 35%-40% of the total area of the cathode catalyst layer; (2) In the cathode catalyst layer, the area of the first water outlet region accounts for 32%-38% of the total area of the cathode catalyst layer; (3) In the anode catalyst layer, the area of the second water inlet region accounts for 35%-40% of the total area of the anode catalyst layer; (4) In the anode catalyst layer, the area of the second water outlet region accounts for 32%-38% of the total area of the anode catalyst layer.
3. The membrane electrode as described in claim 2, characterized in that, The membrane electrode satisfies one or more of the following conditions: (1) In the cathode catalyst layer, the area of the first water inlet region accounts for 35% or 40% of the total area of the cathode catalyst layer; (2) In the cathode catalyst layer, the area of the first water outlet region accounts for 35% of the total area of the cathode catalyst layer; (3) In the anode catalyst layer, the area of the second water inlet region accounts for 35% or 40% of the total area of the anode catalyst layer; (4) In the anode catalyst layer, the area of the second water outlet region accounts for 35% of the total area of the anode catalyst layer.
4. The membrane electrode according to any one of claims 1-3, characterized in that, The cathode catalyst layer satisfies one or more of the following conditions: (1) In the first inlet region, the loading of catalyst A is 0.09 mg / cm³. 2 Or 0.16 mg / cm 2 ; (2) In the first outlet region, the loading of catalyst A is 0.16 mg / cm³. 2 Or 0.25 mg / cm 2 ; (3) The loading of catalyst A in the first inlet region is 0.07 mg / cm³ lower than that in the first outlet region. 2 Or 0.09 mg / cm 2 .
5. The membrane electrode as described in any one of claims 1-3, characterized in that, The cathode catalyst layer satisfies one or more of the following conditions: (1) In the first inlet region, the loading of catalyst A is (0.15-0.18) mg / cm³. 2 ; (2) In the first outlet region, the loading of catalyst A is (0.20-0.25) mg / cm³. 2 ; (3) The loading of catalyst A in the first inlet region is (0.08-0.12) mg / cm³ lower than that in the first outlet region. 2 .
6. The membrane electrode according to any one of claims 1-3, characterized in that, The anode catalyst layer satisfies one or more of the following conditions: (1) In the second inlet region, the loading of catalyst B is 1.1 mg / cm³. 2 Or 1.82 mg / cm 2 ; (2) In the second effluent region, the loading of catalyst B is 1.8 mg / cm³. 2 Or 2.1 mg / cm 2 ; (3) The loading of catalyst B in the second inlet region is 0.28 or 0.7 lower than the loading of catalyst B in the second outlet region.
7. The membrane electrode according to any one of claims 1-3, characterized in that, The anode catalyst layer satisfies one or more of the following conditions: (1) In the second inlet region, the loading of catalyst B is (1.5-1.9) mg / cm³. 2 ; (2) In the second outlet region, the loading of catalyst B is (1.9-2.2) mg / cm³. 2 ; (3) The loading of catalyst B in the second inlet region is (0.2-0.4) mg / cm³ lower than that in the second outlet region. 2 .
8. The membrane electrode according to any one of claims 1-3, characterized in that, Catalyst A is a platinum-carbon catalyst; And / or, the catalyst B is an iridium oxide catalyst.
9. The membrane electrode according to any one of claims 1-3, characterized in that, The raw materials for the first water inlet region, the transition region 1, and the first water outlet region each include catalyst A, ethanol, a saturated monohydric alcohol with 3 carbon atoms, and a Nafion membrane solution.
10. The membrane electrode as claimed in claim 9, characterized in that, In the first water inlet region, the mass ratio of the catalyst A, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is (163-180):(8-9.5):(80-83):
1.
11. The membrane electrode as claimed in claim 9, characterized in that, In the first water inlet region, the mass ratio of the catalyst A, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is 170:9.15:82.4:1 or 179:9.15:82.4:
1.
12. The membrane electrode as claimed in claim 9, characterized in that, In the first water outlet region, the mass ratio of the catalyst A, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is (172-186.6):(8-9.5):(80-83):
1.
13. The membrane electrode as described in claim 9, characterized in that, In the first water outlet region, the mass ratio of the catalyst A, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is 179:9.15:82.4:1 or 186:9.15:82.4:
1.
14. The membrane electrode according to any one of claims 1-3, characterized in that, The raw materials for the second water inlet region, the transition region 2, and the second water outlet region each include catalyst B, ethanol, a saturated monohydric alcohol with 3 carbon atoms, and a Nafion membrane solution.
15. The membrane electrode as claimed in claim 14, characterized in that, In the second water inlet region, the mass ratio of the catalyst B, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is (149.2-153):(7-8.4):(67.9-69):
1.
16. The membrane electrode as claimed in claim 14, characterized in that, In the second water inlet region, the mass ratio of the catalyst B, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is 149.4:7.6:69:1 or 152.5:7.6:69:
1.
17. The membrane electrode as claimed in claim 14, characterized in that, In the second water outlet region, the mass ratio of the catalyst B, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is (152-156.9):(7-8.6):(68.1-69.5):
1.
18. The membrane electrode as claimed in claim 14, characterized in that, In the second water outlet region, the mass ratio of the catalyst B, the ethanol, the saturated monohydric alcohol with 3 carbon atoms, and the Nafion membrane solution is 152:7.6:69:1 or 156:7.6:69:
1.
19. The membrane electrode according to any one of claims 1-3, characterized in that, In the cathode catalyst layer, the I1 / C1 ratio is 0.5-1, where I1 / C1 refers to the mass ratio of perfluorosulfonic acid resin in the Nafion membrane solution in the cathode catalyst layer to the non-precious metal in catalyst A. And / or, in the anode catalyst layer, the I2 / C2 ratio is 0.1-2, where I2 / C2 refers to the mass ratio of perfluorosulfonic acid resin in the Nafion membrane solution in the anode catalyst layer to the non-precious metal in catalyst B.
20. The membrane electrode as claimed in claim 19, characterized in that, In the cathode catalyst layer, the I1 / Cl ratio is 0.6 or 0.8; And / or, in the anode catalyst layer, the I2 / C2 ratio is 0.4 or 0.
5.
21. A method for preparing a membrane electrode as described in any one of claims 1-20, characterized in that, It includes the following steps: (1) The raw materials of the first water inlet region, the raw materials of the transition zone 1, the raw materials of the first water outlet region, the raw materials of the second water inlet region, the raw materials of the transition zone 2 and the raw materials of the second water outlet region are mixed to obtain the first water inlet region slurry, the transition zone 1 slurry, the first water outlet region slurry, the second water inlet region slurry, the transition zone 2 slurry and the second water outlet region slurry respectively. (2) The slurry of the first inlet region is coated on one side of the proton exchange membrane, and the slurry of the second inlet region is coated on the other side of the proton exchange membrane; (3) The transition zone 1 slurry is coated on one side of the proton exchange membrane, and the transition zone 2 slurry is coated on the other side of the proton exchange membrane; (4) The slurry of the first outlet region is coated on one side of the proton exchange membrane, and the slurry of the second outlet region is coated on the other side of the proton exchange membrane; (5) The cathode catalyst layer and the anode catalyst layer are obtained by the coating process; the first gas diffusion layer and the second gas diffusion layer are respectively disposed on the surface of the cathode catalyst layer and the anode catalyst layer.
22. A fuel cell, characterized in that, It includes a membrane electrode as described in any one of claims 1-20.