Preparation method of anti-antipolar gas diffusion layer and anti-antipolar gas diffusion layer

Abstract

The invention discloses a preparation method of an anti-antipolar gas diffusion layer and the anti-antipolar gas diffusion layer. Uniformly dispersing the carbon-nitrogen carrier into a solvent to obtain an electrophoresis solution; immersing the gas diffusion layer into an electrophoresis solution for electrophoresis treatment to obtain an initial gas diffusion layer containing a carbon-nitrogen carrier compound; and immersing the initial gas diffusion layer into a solution containing a noble metal oxide precursor, introducing inert gas into the solution containing the noble metal oxide precursor, and carrying out photochemical deposition treatment under a xenon lamp, so that the noble metal oxide is uniformly distributed on the surface of the initial gas diffusion layer to obtain the anti-antipolar gas diffusion layer. The anti-antipolar catalyst can be uniformly distributed on the surface of the gas diffusion layer through photodeposition, the effective active area of the anti-antipolar catalyst is increased, the anti-antipolar capability of the anti-antipolar gas diffusion layer is enhanced, the preparation method is green, environment-friendly, simple and rapid, and the preparation efficiency can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a preparation method of an anti-reversing polarity gas diffusion layer and the anti-reversing polarity gas diffusion layer. Background Art

[0002] Proton exchange membrane fuel cells (PEMFCs) are electrochemical conversion devices that use hydrogen as an energy source to generate electric current. Due to their high energy conversion efficiency, excellent low-temperature performance, and environmental friendliness, they are widely recognized as the world's ultimate energy source. The membrane electrode (MEA) is the core component of PEMFCs. The MEA typically consists of three main components: a proton exchange membrane, a catalyst layer, and a gas diffusion layer. Its performance and durability directly impact the overall battery life.

[0003] The main functions of the gas diffusion layer are, on the one hand, to transport the anode and cathode reaction gases to the catalytic layer, and on the other hand, to discharge the product water, extract the reaction heat and transfer electrons. As an important place for water and gas transmission, the gas diffusion layer is one of the main factors affecting the performance and durability of proton exchange membrane fuel cells.

[0004] However, automotive proton exchange membrane fuel cells will experience complex operating conditions such as start-stop, idling, high-power operation, and frequent load changes during use. Under these conditions, the anode will experience local hydrogen deficiency. However, in order to maintain the power required by the vehicle, the potential in this area will rise sharply and reverse polarity will occur, leading to water electrolysis and carbon corrosion. The occurrence of carbon corrosion will cause irreversible damage to the structure of the anode catalyst layer, and the nano-metal particles on the carbon carrier will undergo Oswald ripening effect, causing the performance of the proton exchange membrane fuel cell to decay until failure. In addition, the local heat generated will cause pinholes to form on the proton exchange membrane, and these pinholes will cause serious consequences for the proton exchange membrane fuel cell.

[0005] Therefore, to avoid the adverse consequences of carbon corrosion, accelerating the electrolytic oxidation reaction (OER) of water has become the currently known optimal route for anti-reversal. Generally, an anti-reversal gas diffusion layer is prepared by coating a slurry of an anti-reversal catalyst, a resin solution, and a solvent onto the gas diffusion layer. This method is prone to uneven coating, aggregation, and poor dispersion during the coating and drying process. Furthermore, the introduction of the resin affects water vapor transport, meaning that the reactant water cannot reach the surface of the anti-reversal catalyst, and the product gas cannot be discharged in a timely manner, which greatly reduces the catalytic efficiency of the anti-reversal catalyst. Summary of the Invention

[0006] The present application provides a method for preparing an anti-reversing gas diffusion layer and an anti-reversing gas diffusion layer, in which precious metal oxides are deposited on a gas diffusion layer containing carbon and nitrogen compounds by photodeposition. The preparation method is green and environmentally friendly, simple and fast, and can effectively improve the preparation efficiency.

[0007] In one aspect, the present application provides a method for preparing an anti-reversal gas diffusion layer, the method comprising: (1) uniformly dispersing the carbon and nitrogen carrier in a solvent to obtain an electrophoretic solution; (2) immersing the gas diffusion layer in the electrophoresis solution for electrophoresis treatment to obtain an initial gas diffusion layer containing a carbon-nitrogen carrier compound; (3) immersing the initial gas diffusion layer in a solution containing a noble metal oxide precursor, and introducing an inert gas into the solution containing the noble metal oxide precursor to obtain a mixed solution containing the noble metal oxide; (4) placing the mixed solution in a xenon lamp environment and performing a photodeposition process under stirring operation to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer.

[0008] Furthermore, the content of the carbon-nitrogen carrier in the electrophoretic solution of step (1) is 0.1-10 wt %; The solvent in step (1) is one or more of water, ethanol, and isopropanol; The uniform dispersion method in step (1) is one or more of stirring, ultrasonication, cell disruption, and homogenization, and the dispersion time is 1 h to 5 h.

[0009] Furthermore, step (1) includes: heating and grinding a carbon-nitrogen source to obtain the carbon-nitrogen carrier; The carbon-nitrogen carrier is uniformly dispersed in the solvent, and magnesium nitrate is added to obtain the electrophoresis liquid.

[0010] Furthermore, the carbon and nitrogen source is one or more of thiourea, urea, melamine, and dicyandiamide; The heating temperature of the carbon and nitrogen source is 200°C-800°C, and the heating time is 1 h-8 h; In the electrophoretic solution, the content of magnesium nitrate is 0.1-20 wt %.

[0011] Furthermore, during the electrophoresis treatment in step (2), the cathode is the gas diffusion layer and the anode is the platinum mesh; The electrophoresis voltage of the electrophoresis treatment in step (2) is 100 V-200 V, and the electrophoresis time is 1 min-60 min.

[0012] Furthermore, the noble metal precursor in step (3) is one or more of iridium chloride, sodium iridium chloride, iridium chloride, potassium iridium chloride, iridium acetylacetonate, ammonium iridium chloride, potassium iridium chloride, ammonium iridium chloride, ruthenium chloride, ammonium chlororuthenate, ruthenium acetylacetonate, ruthenium nitrosyl nitrate, and potassium chlororuthenate; The inert gas in step (3) is one or more of nitrogen and argon; The time for introducing the inert gas in step (3) is 30 min-120 min.

[0013] Further, step (4) includes: Placing the mixed solution in a xenon lamp environment and performing the photodeposition process under stirring operation to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain an initial anti-reversed polarity gas diffusion layer; The initial anti-reversing polarity gas diffusion layer is cleaned with deionized water, and then vacuum dried to obtain the anti-reversing polarity gas diffusion layer.

[0014] Furthermore, the light illumination power of the light deposition process is 250 W-350 W; The deposition time of the photodeposition process is 1 min to 80 min; The vacuum drying temperature is 60°C-80°C.

[0015] Furthermore, the noble metal precursor is chloroiridic acid; step (4) comprises: placing the mixed solution in a xenon lamp environment, and performing the photodeposition process under stirring operation, and obtaining the anti-reversed polarity gas diffusion layer after cleaning and vacuum drying; The light deposition process illumination power is 280 W-320 W, The deposition time of the photodeposition is 10 min-60 min; The vacuum drying temperature is 60°C-80°C.

[0016] Another aspect provides an anti-reversing gas diffusion layer, which is prepared using the above-mentioned preparation method. The surface of the anti-reversing gas diffusion layer is uniformly distributed with noble metal oxide, and the particle size of the noble metal oxide is less than 5 nm.

[0017] The preparation method of the anti-reversing gas diffusion layer and the anti-reversing gas diffusion layer provided in this application have the following technical effects: The present application uniformly disperses the carbon-nitrogen carrier into a solvent to obtain an electrophoretic liquid; immerses the gas diffusion layer into the electrophoretic liquid for electrophoresis treatment to obtain an initial gas diffusion layer containing a carbon-nitrogen carrier compound; immerses the initial gas diffusion layer in a solution containing a noble metal oxide precursor, and introduces an inert gas into the solution containing the noble metal oxide precursor to obtain a mixed solution containing noble metal oxides; the mixed solution is placed in a xenon lamp environment, and subjected to photochemical deposition treatment under stirring operation to uniformly distribute the noble metal oxides on the surface of the initial gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer. The present application deposits the noble metal oxides on the gas diffusion layer containing the carbon-nitrogen compound by photodeposition, which can make the anti-reverse polarity catalyst uniformly distributed and in situ grown on the surface of the gas diffusion layer, and the photodeposition method is green, energy-saving and environmentally friendly, simple and fast, and can effectively improve the preparation efficiency; in addition, the noble metal oxides are distributed on the surface of the carbon-nitrogen carrier by photodeposition and will not be covered by the carbon-nitrogen carrier, which can increase the effective active area of ​​the anti-reverse polarity catalyst, save the amount of precious metal, and further enhance the anti-reverse polarity ability of the anti-reverse polarity gas diffusion layer.

[0018] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions and advantages of the embodiments of this specification or the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 This is a schematic flow chart of a method for preparing an anti-reversal gas diffusion layer provided in an embodiment of this specification; Figure 2 This is a schematic flow chart of a method for photodeposition provided in an embodiment of this specification; Figure 3 This is a scanning electron microscope image of an anti-reversed polarity gas diffusion layer provided in an embodiment of this specification. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] The following describes a method for preparing an anti-reverse polarity gas diffusion layer of the present invention, specifically Figure 1 As shown, the method may include: (1) uniformly dispersing the carbon and nitrogen carrier in a solvent to obtain an electrophoretic solution; (2) immersing the gas diffusion layer in the electrophoresis solution for electrophoresis treatment to obtain an initial gas diffusion layer containing a carbon-nitrogen carrier compound; (3) immersing the initial gas diffusion layer in a solution containing a noble metal oxide precursor, and introducing an inert gas into the solution containing the noble metal oxide precursor to obtain a mixed solution containing the noble metal oxide; (4) placing the mixed solution in a xenon lamp environment and performing a photodeposition process under stirring operation to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer.

[0023] The present application deposits precious metal oxides on a gas diffusion layer containing carbon and nitrogen compounds through photodeposition, which can make the anti-reversal catalyst evenly distributed and grow in situ on the surface of the gas diffusion layer. In addition, the photodeposition method is green, energy-saving and environmentally friendly, simple and fast, and can effectively improve the preparation efficiency. In addition, the precious metal oxides are distributed on the surface of the carbon and nitrogen carrier through photodeposition and will not be covered by the carbon and nitrogen carrier, which can increase the effective active area of ​​the anti-reversal catalyst, save the amount of precious metal, and further enhance the anti-reversal ability of the anti-reversal gas diffusion layer.

[0024] In an embodiment of the present application, a carbon-nitrogen carrier is first uniformly dispersed in a solvent to prepare an electrophoretic solution. A gas diffusion layer is then immersed in the electrophoretic solution for electrophoresis treatment, so that the carbon-nitrogen carrier is uniformly distributed on the surface of the clean gas diffusion layer, thereby obtaining an initial gas diffusion layer containing the carbon-nitrogen carrier compound. The prepared initial gas diffusion layer containing the carbon-nitrogen carrier compound is then immersed in a solution containing a noble metal oxide precursor, and an inert gas is introduced. After the aeration is completed, the solution is stirred under a xenon lamp for photodeposition, so that the noble metal oxide is uniformly distributed on the surface of the initial gas diffusion layer, thereby preparing an anti-reverse polarity gas diffusion layer. The stirring speed during photodeposition is determined by the volume of the solution, as long as the solution is uniformly mixed.

[0025] In the embodiment of the present application, the content of the carbon-nitrogen carrier in the electrophoresis solution in step (1) can be 0.1-10 wt %; The solvent in step (1) above may be one or more of water, ethanol, and isopropanol; The uniform dispersion method in the above step (1) can be one or more of stirring, ultrasound, cell disruption, and homogenization. The dispersion time can be 1 h to 5 h, preferably 3 h, to ensure that the carbon and nitrogen carrier can be uniformly dispersed in the solvent.

[0026] Furthermore, the above step (1) may include: heating and grinding a carbon-nitrogen source to obtain the carbon-nitrogen carrier; The carbon-nitrogen carrier is uniformly dispersed in the solvent, and magnesium nitrate is added to obtain the electrophoresis liquid.

[0027] In the embodiment of the present application, the carbon and nitrogen source may be one or more of thiourea, urea, melamine, and dicyandiamide; The heating temperature of the carbon and nitrogen source can be 200°C-800°C, and the heating time can be 1 h-8 h; wherein, the preferred heating temperature is 550°C, and the preferred heating time is 2 h; In the electrophoretic solution, the content of magnesium nitrate is 0.1-20 wt %, preferably 10 wt %.

[0028] Specifically, the carbon and nitrogen source may be thiourea, and the electrophoretic fluid preparation method may include: heating thiourea at 550° C. for 2 hours, grinding to obtain a carbon and nitrogen carrier, placing the prepared carbon and nitrogen carrier in ethanol, ultrasonically dispersing it for 3 hours, adding magnesium nitrate, and mixing uniformly to obtain an electrophoretic fluid. The electrophoretic fluid contains 10 wt % of magnesium nitrate.

[0029] In the embodiment of the present application, a nitrogen-carbon source is heated and ground to obtain a nitrogen-carbon carrier, and the carbon-nitrogen carrier is formulated into an electrophoresis liquid, so that the carbon-nitrogen carrier can be distributed on the surface of a clean gas diffusion layer by electrophoresis. In addition, the carbon-nitrogen carrier can also enhance the anti-reverse polarity ability of the anti-reverse polarity gas diffusion layer.

[0030] In an embodiment of the present application, the carbon and nitrogen carrier is uniformly dispersed in the above-mentioned solvent, i.e., one or more of water, ethanol, and isopropanol, to obtain an initial electrophoretic solution, magnesium nitrate is added to the initial electrophoretic solution, and stirred evenly to ensure that magnesium nitrate is uniformly dispersed in the electrophoretic solution to obtain a final electrophoretic solution. Magnesium nitrate is an electrolyte that can dissociate magnesium ions and nitrate ions, increase the ion concentration in the electrophoretic solution, thereby improving the conductivity of the electrophoretic solution, ensuring stable transmission and uniform distribution of current during electrophoresis, and is conducive to improving the electrophoretic effect, so that the carbon and nitrogen carrier is uniformly distributed on the surface of the gas diffusion layer. The addition of magnesium nitrate can also enable the carbon and nitrogen carrier to be deposited more quickly and stably on the surface of the gas diffusion layer; in addition, the nitrate ions in magnesium nitrate have certain acidity, which can reduce the pH value of the electrophoretic solution, thereby suppressing the hydrolysis of other metal ions, and is conducive to maintaining the stability of the electrophoretic solution, preventing precipitation or adverse reactions caused by impurity hydrolysis.

[0031] In the embodiment of the present application, the carbon-nitrogen carrier is prepared as an electrophoretic fluid and magnesium nitrate is added, so that the carbon-nitrogen carrier in the electrophoretic fluid can be deposited on the surface of the gas diffusion layer more quickly and stably.

[0032] Furthermore, during the electrophoresis treatment in step (2), the cathode is a gas diffusion layer and the anode is a platinum mesh; The electrophoresis voltage of the electrophoresis treatment in step (2) is 100 V-200 V, and the electrophoresis time is 1 min-60 min. The electrophoresis time and voltage can be adjusted according to actual needs. Generally, there is a negative correlation between the electrophoresis voltage and the electrophoresis time. When the electrophoresis voltage is 100 V-150 V, the electrophoresis time can be set to 40 min-60 min. When the electrophoresis voltage is 150 V-180 V, the electrophoresis time can be set to 10 min-40 min. When the electrophoresis voltage is 180 V-200 V, the electrophoresis time can be set to 1 min-10 min.

[0033] In an embodiment of the present application, a clean gas diffusion layer can be immersed in the electrophoresis solution prepared above, and electrophoresis is performed with the clean gas diffusion layer as the cathode and the clean platinum mesh as the anode. The carbon and nitrogen carriers are evenly distributed on the surface of the clean gas diffusion layer by electrophoresis to obtain a gas diffusion layer containing carbon and nitrogen carriers. For example, acetone can be used to gently rinse the gas diffusion layer to obtain a clean gas diffusion layer. The traditional anti-reversal gas diffusion layer is to prepare a slurry of anti-reversal catalyst, resin solution and solvent and apply it on the gas diffusion layer. This method is prone to uneven coating, aggregation and poor dispersion during coating and drying. In addition, the introduction of resin will affect water vapor transmission, that is, the reactant water cannot reach the surface of the anti-reversal catalyst, thereby causing the product gas to be unable to be discharged in time, which greatly reduces the catalytic efficiency of the anti-reversal catalyst. However, the electrophoresis method can make the carbon and nitrogen carriers evenly loaded on the surface of the gas diffusion layer, effectively avoiding the aggregation and poor dispersion problems caused by the coating method, and improving the catalytic efficiency.

[0034] In the embodiment of the present application, the electrophoresis treatment is not limited to one time, but can be performed two or more times to make the carbon and nitrogen carriers evenly distributed on the surface of the gas diffusion layer. For example: Immerse the clean gas diffusion layer in the electrophoresis solution, use the gas diffusion layer as the cathode and the platinum mesh as the anode, and perform electrophoresis at 100 V to 150 V for 1 min to 60 min to obtain an electrophoresis product; The secondary electrophoresis treatment is performed at 100 V to 200 V for 1 min to 60 min, so that the carbon and nitrogen carriers are evenly distributed on the surface of the clean gas diffusion layer to obtain an initial gas diffusion layer.

[0035] Furthermore, the above method may include: Immerse the clean gas diffusion layer in the electrophoresis solution, use the gas diffusion layer as the cathode and the platinum mesh as the anode, and perform electrophoresis at 100 V to 150 V for 20 min to 30 min to obtain an electrophoresis product; A secondary electrophoresis treatment is performed at 180 V to 200 V for 1 min to 5 min to make the carbon and nitrogen carriers evenly distributed on the clean gas diffusion layer surface to obtain an initial gas diffusion layer.

[0036] Furthermore, the above method may further include: Immerse the clean gas diffusion layer in the electrophoresis solution, use the gas diffusion layer as the cathode and the platinum mesh as the anode, and perform electrophoresis at 180 V-200 V for 1 min-5 min to obtain an electrophoresis product; A secondary electrophoresis treatment is performed at 100 V to 150 V for 20 min to 30 min to make the carbon and nitrogen carriers evenly distributed on the clean gas diffusion layer surface to obtain an initial gas diffusion layer.

[0037] In the embodiment of the present application, the voltage and time of multiple electrophoresis treatments may be different and may be adjusted according to actual electrophoresis results so that the carbon and nitrogen carriers are evenly distributed on the clean surface of the gas diffusion layer.

[0038] In the embodiment of the present application, the carbon-nitrogen carrier is uniformly loaded on the surface of a clean gas diffusion layer by electrophoresis, thereby avoiding obstruction of water vapor transmission on the surface of the anti-reversal catalyst and effectively improving the catalytic efficiency of the anti-reversal catalyst.

[0039] Furthermore, the precious metal precursor in the above step (3) can be one or more of iridium chlorooxide, sodium iridium chlorooxide, iridium chloride, potassium iridium chlorooxide, iridium acetylacetonate, ammonium iridium chlorooxide, potassium iridium chlorooxide, ammonium iridium chlorooxide, ruthenium chloride, ammonium chlororuthenate, ruthenium acetylacetonate, ruthenium nitrosyl nitrate, and potassium chlororuthenate. The specific usage and dosage can be selected and adjusted according to actual needs.

[0040] In step (3), the inert gas may be one or more of nitrogen and argon; The time for introducing the inert gas in step (3) can be 30 min-120 min. For example, the ventilation time can be 30 min, 35 min, 40 min, 50 min, 55 min, 70 min, 95 min, 100 min, and 120 min.

[0041] In an embodiment of the present application, the noble metal precursor is uniformly dispersed in a dispersion solvent, which may be one or more of ultrapure water and ethanol, to obtain a solution containing a noble metal oxide precursor, and the initial gas diffusion layer prepared above, the surface of which is loaded with a carbon-nitrogen carrier, is immersed in the solution containing the noble metal precursor obtained above, and then an inert gas is introduced, and the ventilation time may be 30 min-120 min to avoid oxidation or other unwanted chemical reactions, thereby obtaining a mixed solution.

[0042] In the embodiments of the present application, a high-performance catalyst can be prepared using a noble metal precursor. The noble metal precursor is prepared as a solution, and the noble metal oxide is evenly distributed on the surface of a gas diffusion layer loaded with a carbon-nitrogen carrier by a photodeposition method. This can prepare an anti-reverse polarity catalyst with better catalytic performance, thereby enhancing the anti-reverse polarity capability of the anti-reverse polarity gas diffusion layer.

[0043] Specifically, the noble metal precursor may be iridium chloride, and the step of preparing a solution containing the noble metal precursor may include: dispersing iridium chloride in ethanol, mixing uniformly, and introducing nitrogen for 30 minutes to obtain a solution containing the noble metal precursor.

[0044] The embodiment of the present application prepares the precious metal precursor into a solution and introduces an inert gas to prevent oxidation or other unwanted reactions during the subsequent photodeposition process, thereby improving the preparation efficiency of the anti-reverse polarity gas diffusion layer and ensuring the quality and efficiency of the preparation process.

[0045] Furthermore, if Figure 2 As shown, the above step (4) may include: (41) placing the mixed solution in a xenon lamp environment and performing the photodeposition process under stirring operation to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain an initial anti-reverse polarity gas diffusion layer; (42) The initial anti-reversing gas diffusion layer is cleaned with deionized water, and then vacuum dried to obtain the anti-reversing gas diffusion layer.

[0046] Furthermore, the illumination power of the photodeposition process may be 250 W to 350 W, preferably 300 W; The deposition time of the photodeposition treatment can be 1 min-80 min, preferably 20 min; the illumination time and power can be adjusted according to the loading amount of the noble metal oxide and the reactants; The vacuum drying temperature may be 60°C to 80°C, for example, 60°C, 65°C, 68°C, 70°C, 72°C, 75°C, 80°C, etc.

[0047] In an embodiment of the present application, the ventilated mixed solution is placed under a xenon lamp and photodeposited at room temperature, and is stirred evenly during the deposition process to ensure that the precious metal oxide is evenly distributed on the surface of the initial gas diffusion layer to obtain an initial anti-reverse polarity gas diffusion layer.

[0048] In the embodiment of the present application, photodeposition is not limited to being performed once, but may be performed twice or more times to ensure that the precious metal oxide can be evenly distributed and in situ grown on the surface of the gas diffusion layer loaded with a carbon-nitrogen carrier, so that the anti-reverse polarity catalyst can be evenly distributed on the surface of the gas diffusion layer, thereby increasing the effective active area of ​​the catalyst and enhancing the anti-reverse polarity capability of the anti-reverse polarity gas diffusion layer.

[0049] In the embodiment of the present application, the precious metal oxide is deposited on the surface of the gas diffusion layer loaded with a carbon-nitrogen carrier by the method of photodeposition, so that the anti-reversal catalyst is evenly distributed on the surface of the gas diffusion layer. The photochemical deposition method is green, energy-saving and environmentally friendly, and is simple and fast, which effectively improves the preparation efficiency. In addition, the precious metal oxide is distributed on the surface of the carbon-nitrogen carrier and is not covered by the carbon-nitrogen compounds, which can increase the effective active area, save the amount of precious metal, and further enhance the anti-reversal ability of the anti-reversal gas diffusion layer.

[0050] Specifically, the noble metal precursor may be chloroiridic acid; step (4) may include: placing the mixed solution in a xenon lamp environment, and performing the photodeposition process under stirring, and obtaining the anti-reverse polarity gas diffusion layer after cleaning and vacuum drying; wherein the light irradiation power of the photodeposition process is 280 W-320 W, the deposition time of the photodeposition is 10 min-60 min, and the vacuum drying temperature is 60°C-80°C.

[0051] The embodiment of the present application further provides an anti-reversing gas diffusion layer, which is prepared using the above-mentioned preparation method. Precious metal oxides are evenly distributed on the surface of the anti-reversing gas diffusion layer, and the particle size of the precious metal oxides is less than 5 nm.

[0052] In the embodiment of the present application, the anti-reversing gas diffusion layer can be prepared by adopting the above-mentioned preparation method. The scanning electron microscope image (SEM image) of the anti-reversing gas diffusion layer is as follows: Figure 3 As shown by Figure 3 It can be seen that the surface of the anti-reversal gas diffusion layer is uniformly distributed with precious metal oxides, and the particle size of the precious metal oxides is less than 5 nm. This shows that the optical deposition method can effectively deposit precious metal oxides on the surface of the gas diffusion layer loaded with carbon and nitrogen carriers. The uniform distribution of precious metal oxides is not covered by the carbon and nitrogen carriers, which can increase the effective catalytic active area, save precious metal usage, reduce preparation costs, and enhance the anti-reversal capability of the anti-reversal gas diffusion layer.

[0053] Example 1: This embodiment provides an anti-reverse polarity gas diffusion layer and a preparation method thereof. The specific preparation method includes: The carbon and nitrogen carrier is uniformly dispersed in a solvent to obtain an electrophoresis solution; the content of the carbon and nitrogen carrier in the electrophoresis solution is 0.1 wt%; Immersing the clean gas diffusion layer in an electrophoresis solution for electrophoresis treatment to uniformly distribute the carbon and nitrogen carriers on the surface of the clean gas diffusion layer, thereby obtaining an initial gas diffusion layer containing the carbon and nitrogen carrier compounds; The initial gas diffusion layer is immersed in a solution containing a noble metal oxide precursor, and an inert gas is introduced into the solution containing the noble metal oxide precursor for 30 minutes to obtain a mixed solution containing the noble metal oxide; The mixed solution was placed under a xenon lamp for photodeposition treatment to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; the light power of the photodeposition treatment was 250 W and the deposition time was 80 min.

[0054] Example 2: This embodiment provides an anti-reverse polarity gas diffusion layer and a preparation method thereof. The specific preparation method includes: The carbon and nitrogen carrier is uniformly dispersed in a solvent to obtain an electrophoretic solution; the content of the carbon and nitrogen carrier in the electrophoretic solution is 10 wt %; Immersing the clean gas diffusion layer in an electrophoresis solution for electrophoresis treatment to uniformly distribute the carbon and nitrogen carriers on the surface of the clean gas diffusion layer, thereby obtaining an initial gas diffusion layer containing the carbon and nitrogen carrier compounds; The initial gas diffusion layer is immersed in a solution containing a noble metal oxide precursor, and an inert gas is introduced into the solution containing the noble metal oxide precursor for 120 minutes to obtain a mixed solution containing the noble metal oxide; The mixed solution was placed under a xenon lamp for photodeposition treatment to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; the light power of the photodeposition treatment was 350 W and the deposition time was 1 min.

[0055] Example 3: This embodiment provides an anti-reverse polarity gas diffusion layer and a preparation method thereof. The specific preparation method includes: The carbon and nitrogen carrier is uniformly dispersed in a solvent to obtain an electrophoresis solution; the content of the carbon and nitrogen carrier in the electrophoresis solution is 5wt%; Immersing the clean gas diffusion layer in an electrophoresis solution for electrophoresis treatment to uniformly distribute the carbon and nitrogen carriers on the surface of the clean gas diffusion layer, thereby obtaining an initial gas diffusion layer containing the carbon and nitrogen carrier compounds; The initial gas diffusion layer is immersed in a solution containing a noble metal oxide precursor, and an inert gas is introduced into the solution containing the noble metal oxide precursor for 60 minutes to obtain a mixed solution containing the noble metal oxide; The mixed solution was placed under a xenon lamp for photodeposition treatment to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; the light power of the photodeposition treatment was 300 W and the deposition time was 30 min.

[0056] Example 4: This embodiment provides an anti-reverse polarity gas diffusion layer and a preparation method thereof. The specific preparation method includes: The carbon and nitrogen carrier is uniformly dispersed in a solvent to obtain an electrophoresis solution; the content of the carbon and nitrogen carrier in the electrophoresis solution is 5wt%; Immersing the clean gas diffusion layer in an electrophoresis solution for electrophoresis treatment to uniformly distribute the carbon and nitrogen carriers on the surface of the clean gas diffusion layer, thereby obtaining an initial gas diffusion layer containing the carbon and nitrogen carrier compounds; The initial gas diffusion layer is immersed in a solution containing a noble metal oxide precursor, and an inert gas is introduced into the solution containing the noble metal oxide precursor for 40 minutes to obtain a mixed solution containing the noble metal oxide; The mixed solution was placed under a xenon lamp for photodeposition treatment to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer; the light power of the photodeposition treatment was 300 W and the deposition time was 20 min.

[0057] As can be seen from the embodiments provided by the present application, the present application uniformly disperses the carbon-nitrogen carrier into the solvent to obtain an electrophoretic solution; immerses the gas diffusion layer in the electrophoretic solution for electrophoresis treatment to obtain an initial gas diffusion layer containing a carbon-nitrogen carrier compound; immerses the initial gas diffusion layer in a solution containing a noble metal oxide precursor, and introduces an inert gas into the solution containing the noble metal oxide precursor to obtain a mixed solution containing noble metal oxides; the mixed solution is placed in a xenon lamp environment and subjected to photochemical deposition under stirring operation to uniformly distribute the noble metal oxides on the surface of the initial gas diffusion layer to obtain an anti-reverse polarity gas diffusion layer. The present application deposits the noble metal oxides on the gas diffusion layer containing the carbon-nitrogen compound by photodeposition, which can uniformly distribute the anti-reverse polarity catalyst and grow it in situ on the surface of the gas diffusion layer. Moreover, the photodeposition method is green, energy-saving and environmentally friendly, simple and fast, and can effectively improve the preparation efficiency. In addition, the noble metal oxides are distributed on the surface of the carbon-nitrogen carrier by photodeposition and will not be covered by the carbon-nitrogen carrier, which can increase the effective active area of ​​the anti-reverse polarity catalyst, save the amount of precious metal, and further enhance the anti-reverse polarity ability of the anti-reverse polarity gas diffusion layer.

[0058] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for preparing an anti-reversal gas diffusion layer, characterized in that: The method comprises: (1) uniformly dispersing the carbon and nitrogen carrier in a solvent to obtain an electrophoretic solution; (2) immersing the gas diffusion layer in the electrophoresis solution for electrophoresis treatment to obtain an initial gas diffusion layer containing a carbon-nitrogen carrier compound; (3) immersing the initial gas diffusion layer in a solution containing a noble metal oxide precursor and introducing an inert gas to obtain a mixed solution containing the noble metal oxide; (4) placing the mixed solution in a xenon lamp environment and performing a photodeposition process under stirring operation to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain the anti-reverse polarity gas diffusion layer.

2. The method according to claim 1, characterized in that The content of the carbon-nitrogen carrier in the electrophoresis solution in step (1) is 0.1-10 wt %; The solvent in step (1) is one or more of water, ethanol, and isopropanol; The uniform dispersion method in step (1) is one or more of stirring, ultrasonication, cell disruption, and homogenization, and the dispersion time is 1 h to 5 h.

3. The method according to claim 2, characterized in that Step (1) includes: heating and grinding a carbon-nitrogen source to obtain the carbon-nitrogen carrier; The carbon-nitrogen carrier is uniformly dispersed in the solvent, and magnesium nitrate is added to obtain the electrophoresis liquid.

4. The method according to claim 3, characterized in that The carbon and nitrogen source is one or more of thiourea, urea, melamine, and dicyandiamide; The heating temperature of the carbon and nitrogen source is 200°C-800°C, and the heating time is 1 h-8 h; In the electrophoretic solution, the content of magnesium nitrate is 0.1-20 wt %.

5. The method according to claim 1, wherein During the electrophoresis treatment in step (2), the cathode is the gas diffusion layer and the anode is the platinum mesh; The electrophoresis voltage of the electrophoresis treatment in step (2) is 100 V-200 V, and the electrophoresis time is 1 min-60 min.

6. The method according to claim 1, characterized in that The noble metal precursor in step (3) is one or more of iridium chloride, sodium iridium chloride, iridium chloride, potassium iridium chloride, iridium acetylacetonate, ammonium iridium chloride, potassium iridium chloride, ammonium iridium chloride, ruthenium chloride, ammonium chlororuthenate, ruthenium acetylacetonate, ruthenium nitrosyl nitrate, and potassium chlororuthenate; The inert gas in step (3) is one or more of nitrogen and argon; The time for introducing the inert gas in step (3) is 30 min-120 min.

7. The method according to claim 1, characterized in that Step (4) includes: Placing the mixed solution in a xenon lamp environment and performing the photodeposition process under stirring operation to uniformly distribute the noble metal oxide on the surface of the initial gas diffusion layer to obtain an initial anti-reversed polarity gas diffusion layer; The initial anti-reversing polarity gas diffusion layer is cleaned with deionized water, and then vacuum dried to obtain the anti-reversing polarity gas diffusion layer.

8. The method according to claim 7, wherein The illumination power of the photodeposition process is 250 W-350 W; The deposition time of the photodeposition process is 1 min to 80 min; The vacuum drying temperature is 60°C-80°C.

9. The method according to claim 8, characterized in that The noble metal precursor is chloroiridic acid; step (4) comprises: placing the mixed solution in a xenon lamp environment, and performing the photodeposition process under stirring operation, and obtaining the anti-reverse polarity gas diffusion layer after cleaning and vacuum drying; The light deposition process illumination power is 280 W-320 W, The deposition time of the photodeposition is 10 min-60 min; The vacuum drying temperature is 60°C-80°C.

10. An anti-reverse polarity gas diffusion layer, characterized in that: The anti-reversing gas diffusion layer is prepared by the preparation method according to any one of claims 1 to 9. Precious metal oxides are evenly distributed on the surface of the anti-reversing gas diffusion layer, and the particle size of the precious metal oxides is less than 5 nm.

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