Carrier material and its manufacturing method

Abstract

The present application discloses a carrier material and a manufacturing method thereof, which includes the steps of dispersing a template agent in a metal salt mixed solution to obtain a first product with a specific concentration, vacuum drying the first product at a low temperature to obtain a second product, mixing an organic carbon source with the second product to obtain a third product, subjecting the third product to a first heat treatment under vacuum or inert gas conditions to obtain a fourth product, washing the fourth product with an acid pickling solution and drying it to obtain a fifth product, and subjecting the fifth product to a second heat treatment to obtain a carrier material, wherein the pore characteristic value of the carrier material is smaller than the cavity characteristic value of the carrier material.

Description

[Technical Field]

[0001] This application claims priority to Chinese patent application No. 202410874263.9 filed on June 27, 2024, and Chinese patent application No. 202311295382.0 filed on September 28, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of fuel cells, and in particular to carrier materials and methods for their manufacture. [Background technology]

[0003] The membrane electrode is the core component of a fuel cell, and the catalyst in the membrane electrode can convert chemical energy into electrical energy. The three components, gas, electrons, and protons, undergo an electrochemical reaction on the catalyst surface to produce water, which then supplies energy to the connected load device. The membrane electrode is provided with a carrier material that supports the catalyst, and the carrier material provides continuous transmission channels for protons, reactant gases, and water for the electrochemical reaction.

[0004] The fine particles of the carrier material are often configured as a porous structure so that the carrier material has a large specific surface area, which provides more attachment sites for the precious metal particles in the catalyst and provides reaction sites for the catalytic reaction. Summary of the Invention [Problem to be solved by the invention]

[0005] The embodiments of the present application provide a carrier material and a manufacturing method thereof to solve the problem of high mass transfer resistance in existing membrane electrodes. [Means for solving the problem]

[0006] The present application is directed to 1. A method for producing a carrier material, comprising: Dispersing a template agent in a metal salt mixture solution to obtain a first product having a specific concentration; low-temperature vacuum drying the first product to obtain a second product; combining an organic carbon source with the second product to obtain a third product; performing a first heat treatment on the third product under vacuum or inert gas conditions to obtain a fourth product; washing the fourth product with an acid wash solution and drying to obtain a fifth product; and performing a second heat treatment on the fifth product to obtain a carrier material; The fine particles of the carrier material are configured to have a plurality of pores and a plurality of cavities, the pores being in communication with the exterior of the fine particles, and the cavities being isolated from the exterior of the fine particles; When the ratio of the mass of the carrier material to the total volume of the pores is defined as the pore characteristic value, and the ratio of the mass of the carrier material to the total volume of the cavities is defined as the cavity characteristic value, the pore characteristic value of the carrier material is smaller than the cavity characteristic value of the carrier material; It is realized to provide a method for manufacturing a carrier material.

[0007] The method for manufacturing a carrier material provided by the above embodiment of the present application further provides a carrier material manufactured by the above-mentioned method for manufacturing a carrier material.

[0008] Accordingly, embodiments of the present application further provide a membrane electrode for a fuel cell comprising the aforementioned carrier material. [Brief explanation of the drawings]

[0009] In order to more clearly explain the technical solutions in the embodiments of the present application, the following will briefly describe the drawings used in the description of the embodiments. Of course, the drawings in the following description are only a part of the embodiments of the present application, and those skilled in the art can derive other drawings from these drawings without any creative efforts.

[0010] [Figure 1]1 is a structural schematic diagram of a fuel cell provided by an embodiment of the present application; [Figure 2] 1 is a schematic diagram of the main steps of the method for manufacturing a carrier material provided by an embodiment of the present application. [Figure 3] 1 is a schematic diagram of the microstructure of a catalyst layer provided by an example of the present application. [Figure 4] 1 is a structural schematic diagram of the carrier material provided by the embodiment of the present application when combined with catalyst particles; [Figure 5] 1 is a schematic diagram of the main steps of a method for manufacturing a catalyst layer provided by an embodiment of the present application. [Figure 6] FIG. 1 is a structural schematic diagram of an equivalent circuit for an EIS test. [Figure 7] 1 is a schematic diagram of the pore characteristic values ​​and mass transport impedance rules of carrier materials provided by examples of the present application; [Figure 8] 1 is a schematic diagram of the rules for the cavity characteristic value and ECSA retention rate of a carrier material provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Of course, the described embodiments are only a part of the embodiments of the present application, and are not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without requiring creative efforts shall fall within the scope of protection of the present application. It should be understood that the embodiments for implementing the invention described herein are only used to explain and interpret the present application, and are not intended to limit the present application.

[0012] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art of the present invention. The terms used in the present specification are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0013] In this application, unless otherwise specified, the terms used to indicate orientation, such as "up" and "down," generally refer to the up and down of the device in its actual use or working state, specifically the direction shown in the drawings, and "inside" and "outside" refer to positions relative to the outline of the device. In addition, in the description of this application, the term "including" means "including, but not limited to." Terms such as first, second, and third are merely used as symbols and do not necessarily require numbers or determine an order.

[0014] In this application, "and / or" is used to describe a related relationship between related objects, and indicates that three relationships can exist. For example, A and / or B can indicate three cases: the presence of only A, the presence of both A and B, and the presence of only B. Here, A and B can be singular or plural.

[0015] As used herein, "at least one" means one or more, and "plurality" means two or more. "One or more," "at least one of the following," or similar expressions, refers to any combination of these terms, including any combination of one or more terms. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can refer to a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c may each be singular or plural.

[0016] Although various embodiments of the present application may be presented in range format, it should be understood that the description in range format is for convenience and brevity only and should not be construed as an inexact limitation on the scope of the present application, and therefore the description of a range as set forth should be considered to specifically disclose all possible subranges and single numerical values ​​within that range. For example, a description of a range of 1 to 6 should be considered to specifically disclose subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., as well as single numerical values ​​within said range such as 1, 2, 3, 4, 5, 6, etc., and this applies regardless of the range. Furthermore, whenever a numerical range is presented herein, it is meant to include any number (fractional or integer) recited within the range as set forth.

[0017] As shown in Figure 1, the fuel cell of the present invention includes two electrodes 100 and a membrane electrode disposed between them. The membrane electrode includes a proton membrane 300, a catalyst layer 400, and a diffusion layer 200. The functions, structures, and manufacturing methods of each part of the fuel cell of the present invention, other than the catalyst layer 400, are common solutions well known to those skilled in the art and are not the focus of the present invention, so they will not be described here.

[0018] The technical solution of the present application is as follows: In a first aspect, as shown in FIG. 2, an embodiment of the present application provides a method for manufacturing a carrier material, which comprises the following main steps: In S110, the template agent is dispersed in the metal salt mixture solution to obtain a first product at a specific concentration.

[0019] Specifically, the template agent includes one or a mixture of two or more of carbon quantum dots, nanoaluminum oxide, nanosilicon oxide, nanomagnesium oxide, nanocalcium oxide, and nanocalcium carbonate.

[0020] The metal salt in the mixed metal salt solution includes one or more of iron nitrate, chromium nitrate, cobalt nitrate, nickel nitrate, zinc nitrate, magnesium nitrate, iron chloride, cobalt chloride, nickel chloride, zinc chloride, magnesium chloride, iron sulfate, iron sulfate, iron sulfate, zinc sulfate, and magnesium sulfate.

[0021] The mixed solvent in the mixed metal salt solution includes a mixture of one or more of isopropyl alcohol, ethylene glycol, n-butanol, N-methylpyrrolidone, and ethanol with distilled water.

[0022] More specifically, the volume ratio of distilled water to the organic solvent in the mixed solvent is within the range of 1-20.

[0023] The mixture of the template agent and the metal salt is uniformly stirred in a sealed container at room temperature to obtain a first product. Step S110 serves to obtain the template agent arranged in a specific manner and to uniformly deposit the metal salt on the template agent.

[0024] The solution concentration of the metal salt mixed solution in step S110 is in the range of 10 mg / mL to 100 mg / mL, and as a further option, the concentration is in the range of 20 mg / mL to 50 mg / mL.

[0025] The particular concentration of the first product in step S110 is in the range of 10 wt.% to 50 wt.%, and as a further option, the concentration is in the range of 20 wt.% to 40 wt.%.

[0026] In S120, the first product is vacuum dried at low temperature to obtain a second product.

[0027] Specifically, the second product is a mixture of template metal salts.

[0028] The temperature for low temperature vacuum drying is in the range of -40°C to 10°C, and as a further option, the temperature is in the range of -30°C to -10°C.

[0029] In S130, an organic carbon source is mixed with the second product to obtain a third product.

[0030] Specifically, the organic carbon source includes one or more of substances such as asphalt, sugar, heavy oil, fatty acid, polyvinyl alcohol, polyamide, epoxy resin, phenolic resin, organic salt, and derivatives thereof.

[0031] More specifically, the mass ratio of the organic carbon source to the second product is 0.1 to 3.

[0032] Step S130 serves to achieve mixing of the template agent with the organic carbon source without destroying the arrangement of the template agent.

[0033] In S140, the third product is subjected to a first heat treatment under vacuum or inert gas conditions to obtain a fourth product.

[0034] Specifically, the first heat treatment in step S140 is performed under vacuum or inert gas conditions, and the inert gas includes one or both of argon gas and nitrogen gas.

[0035] More specifically, the temperature rise rate of the first heat treatment in step S140 is a value within the range of 1°C / min to 20°C / min, and the heat treatment temperature is a value within the range of 200°C to 1000°C.

[0036] As a further option, the temperature rise rate in the first heat treatment is within a range of 5°C / min to 10°C / min, and the heat treatment temperature is within a range of 500°C to 700°C.

[0037] Step S140 serves to carbonize the organic carbon source to obtain a specific pore or cavity structure, where the pores are formed through the pore-forming effect of the template agent and the pore formation through the catalytic action of metal salts, and the carbon source itself also forms pores or cavities during the shrinkage carbonization process. The fourth product is a carbon powder with the specific pore or cavity structure.

[0038] Step S140 serves to allow the templating agent and the metal salt to cooperate to form a product with a certain pore or cavity structure.

[0039] In S150, the fourth product is washed with an acid wash solution and dried to obtain a fifth product.

[0040] Specifically, the pickling solution contains one or more of hydrochloric acid, nitric acid, perchloric acid, sulfuric acid, acetic acid, and hydrofluoric acid.

[0041] The concentration of the amount of substance of the pickling solution is a value in the range of 0.2 mol / L to 5 mol / L, and as a further option, the concentration of the amount of substance of the pickling solution is a value in the range of 0.5 mol / L to 2 mol / L.

[0042] Step S150 aims to remove most of the metal salts and the template agent.

[0043] In S160, the fifth product is subjected to a second heat treatment to obtain a carrier material.

[0044] The purpose of S160 is that some pores close during the graphitization process to form cavities, and the metal salts remaining in some of the cavities react with carbon to form pore structures, while the metals exert varying degrees of graphitization catalytic function to enhance the degree of graphitization of the material.

[0045] Specifically, step S160 mainly includes the following steps: In S161, the fifth product is subjected to a high-temperature heat treatment in an inert atmosphere to obtain an intermediate product.

[0046] Specifically, the inert atmosphere gas contains one or both of argon gas and nitrogen gas.

[0047] The temperature rise rate of the high-temperature heat treatment in step S161 is in the range of 1°C / min to 20°C / min, and the heat treatment temperature is in the range of 1000°C to 2600°C.

[0048] As a further option, the temperature increase rate of the high-temperature heat treatment is within a range of 5°C / min to 10°C / min, and the heat treatment temperature is within a range of 1400°C to 1900°C.

[0049] In S162, the intermediate product is cooled.

[0050] Specifically, the cooling process is carried out so as to allow the material to cool naturally to room temperature.

[0051] In S163, the intermediate product after the cooling treatment is subjected to a medium temperature heat treatment in an oxidizing atmosphere, and after cooling, a carrier material is obtained.

[0052] Specifically, the oxidizing atmosphere gas includes one or more of carbon dioxide, an oxidizing atmosphere containing oxygen (air, water vapor, oxygen gas, ozone, etc.), and ammonia.

[0053] The temperature rise rate of the intermediate heat treatment in step S163 is in the range of 1°C / min to 20°C / min, and the heat treatment temperature is in the range of 150°C to 500°C.

[0054] As a further option, the temperature ramp rate of the medium temperature heat treatment is in the range of 1°C / min to 15°C / min, and the heat treatment temperature is in the range of 200°C to 400°C.

[0055] The above heat treatment method in step S160 is used to control the pore characteristic value and cavity characteristic value of the carrier material 410.

[0056] Among these, high-temperature heat treatment increases the crystallinity of carbon materials, and the higher the crystallinity, the better the corrosion resistance and the smaller the specific surface area. Carbon materials undergo a change known as structural reconstruction at high temperatures, and the graphite microcrystalline layer on the surface polymerizes and rearranges during this process, changing the pore structure (pore diameter, pore volume, etc.), with some of the pores becoming cavities. At the same time, the high temperature releases some metal salts, forming new pore and cavity structures.

[0057] The medium-temperature heat treatment is an oxidation modification process for the material, which reduces the fixed carbon content of the material, increases the elemental content of oxygen, hydrogen, and nitrogen (depending on the synthesis conditions), and increases the content of the corresponding groups, making it easier for precious metal particles to adhere. It also increases the interconnectivity of the pore structure, converting some of the cavity structure into a pore structure.

[0058] In a second embodiment, as shown in FIGS. 3 and 4, the present embodiment provides a carrier material 410, which mainly provides a carrier for catalyst particles 420 (noble metal particles, e.g., Pt nanoparticles) in the catalyst layer 400, and the carrier material 410 is a powder material.

[0059] Specifically, the fine particles of the carrier material 410 of the present application are configured to have a plurality of pores and a plurality of cavities, the pores are connected to the outside of the fine particles, and the cavities are isolated from the outside of the fine particles. If the ratio of the mass of the carrier material 410 to the total volume of the pores is defined as the pore characteristic value, and the ratio of the mass of the carrier material 410 to the total volume of the cavities is defined as the cavity characteristic value, the pore characteristic value of the carrier material 410 is smaller than the cavity characteristic value of the carrier material 410.

[0060] Optionally, the carrier material 410 comprises at least a carbon material.

[0061] The mass transport capacity of carbon materials is related to the size and type of pores. Generally, when the pore diameter is 2 nm or larger, the space can communicate with the outside during the mass transport process, making it easier for continuous and stable reactions to occur. Furthermore, the generated water can be discharged in a timely manner to ensure the continuous progress of the reaction. These spaces are called pores, and include interconnected pores, through pores, and blind pores. The surface area of ​​these pores can be detected and analyzed using gas adsorption methods.

[0062] In addition to these pores, there may be some enclosed spaces within the fine particles of the carrier material 410. These pores have a small diameter (≦2 nm) or are not connected to the outer surface, making it impossible for fluids to penetrate. These spaces cannot be effectively measured by measurement methods such as gas adsorption and mercury intrusion, making it difficult to use them as locations for continuous and stable electrochemical reactions under working conditions.

[0063] Therefore, since the pores in the microparticles of the carrier material of the present application have a pore diameter of 2 nm or less, they are difficult for fluids to enter, and therefore pores with a pore diameter of 2 nm or less can also be classified as cavities as defined in the present application. That is, the phrase "isolated from the outside of the microparticles of the carrier material 410" as used herein refers to a space through which liquid cannot effectively flow. That is, the "cavity" as used herein refers not only to a sealed space that is not completely connected to the outside of the microparticles of the carrier material 410, but also to a pore (non-sealed space) that is connected to the outside of the microparticles of the carrier material 410 but has a pore diameter of 2 nm or less.

[0064] The carbon material has a large pore characteristic value, which greatly improves the mass transfer capacity and reduces the mass transfer resistance under high current density operating conditions. The appropriate pore structure delays phenomena such as catalyst flooding and clogging of gas diffusion pore channels. In addition, a carrier material 410 with a high cavity characteristic value exhibits higher durability under operating conditions such as start-up and shutdown.

[0065] Such porous carbon materials with optimized pores and cavities can similarly be used in other areas related to mass and charge transport processes, such as lithium batteries, sodium ion batteries, and drug delivery.

[0066] In some embodiments, the ratio of the pore characteristic value to the cavity characteristic value of the carrier material 410 is in the range of 0.005 to 0.045.

[0067] In some embodiments, the ratio of the pore characteristic value to the cavity characteristic value of the carrier material 410 is in the range of 0.0102 to 0.0163, more specifically, in the range of 0.014 to 0.015, or 0.0145 to 0.0148.

[0068] In some embodiments, the ratio of the pore characteristic value to the cavity characteristic value of the carrier material 410 is in the range of 0.0232 to 0.0384, more specifically, in the range of 0.020 to 0.030, or 0.025 to 0.028.

[0069] In some embodiments, the ratio of the pore characteristic value to the cavity characteristic value of the carrier material 410 is in the range of 0.0090 to 0.0180, more specifically, in the range of 0.012 to 0.013, or 0.0125 to 0.0129.

[0070] In some embodiments, the carrier material 410 has a pore size of 0.250 g / cm 3 ~0.450g / cm 3 It may be a value in the range

[0071] In some embodiments, the carrier material 410 has a pore size of 0.260 g / cm 3 ~0.350g / cm 3 It may be a value in the range

[0072] In some embodiments, the carrier material 410 has a cavity characteristic value of 10.00 g / cm 3 ~50.00g / cm3 It may be a value in the range

[0073] In some embodiments, the carrier material 410 has a cavity characteristic value of 20.00 g / cm 3 ~40.00g / cm 3 It may be a value in the range

[0074] In some embodiments, the carrier material 410 has a pore size of 0.256 g / cm 3 ~0.298g / cm 3 and the cavity characteristic value of the carrier material 410 may be in the range of 18.306 g / cm 3 ~24.902g / cm 3 It may be a value in the range

[0075] In some embodiments, the carrier material 410 has a pore size of 0.375 g / cm 3 ~0.418g / cm 3 and the cavity characteristic value of the carrier material 410 may be in the range of 10.897 g / cm 3 ~16.105g / cm 3 It may be a value in the range

[0076] In some embodiments, the carrier material 410 has a pore size of 0.260 g / cm 3 ~0.350g / cm 3 and the cavity characteristic value of the carrier material 410 may be in the range of 19.306 g / cm 3 ~30.026g / cm 3 It may be a value in the range

[0077] In some embodiments, the carrier material 410 may have a Pore Characteristic value of 0.284, 0.319, or 0.399.

[0078] In some embodiments, the carrier material 410 may have a cavity characteristic value of 14.298, 19.306, or 24.902.

[0079] In some embodiments, the specific surface area of ​​the carrier material 410 is 400 m 2 / g~1500m 2 / g. As a further option, the specific surface area of ​​the carrier material 410 may be in the range of 500 m 2 / g~1100m 2 / g.

[0080] In some embodiments, the particle size of carrier material 410 may be in the range of 100 nm to 2 μm. As a further option, the particle size of carrier material 410 may be in the range of 200 nm to 800 nm.

[0081] In some embodiments, the compaction density of the carrier material 410 may be a value in the range of 0.05 g / mL to 0.80 g / mL. As a further option, the compaction density of the carrier material 410 may be a value in the range of 0.10 g / mL to 0.50 g / mL.

[0082] In some embodiments, the conductivity of the carrier material 410 may be in the range of 6.4 S / cm to 26.5 S / cm.

[0083] In some embodiments, the fixed carbon content of the carrier material 410 may be in the range of 84.5% to 97.2%.

[0084] In order to quantitatively express the structural characteristics of pores that contribute to the occurrence of mass transfer reactions in carbon materials, in this application, pore characteristic values ​​are used.

number

number

number

number

number

number

number

number

number

number

number

number

number

number

number

number

number

number

number

number

number

number

[0085] Among them, the carrier materials with specific pore structures are as shown in Formulas 4 and 5.

number

number

[0086] Therefore, the pore characteristic value is

number

number

number

number

[0087] The calculation formulas for the pore characteristic value and cavity characteristic value in this application have been explained above, so the true density of the carrier material is shown below.

number

number

number

[0088] In a third aspect, as shown in FIG. 5, an embodiment of the present application provides a method for manufacturing a catalyst layer using the above carrier material, including the following steps: In S210, a certain amount of precious metal precursor is taken and dissolved in an organic solvent, and a certain amount of carrier material 410 is added thereto under vigorous stirring, and the mixture is sealed and stirred uniformly, and then dried to obtain a sixth product.

[0089] Specifically, the organic solvent in S210 includes one or more of ethanol, isopropyl alcohol, ethylene glycol, and n-butanol.

[0090] The noble metal precursor in step S210 includes one or more of chloroplatinic acid, potassium chloroplatinate, potassium tetrachloroplatinate(II), platinum dichloride, platinum tetrachloride, tetraammineplatinum(II) chloride monohydrate, and bis(acetylacetonato)platinum.

[0091] The mass concentration of the noble metal precursor in step S210 is in the range of 0.1 mol / L to 5 mol / L, and more optionally in the range of 1 mol / L to 2 mol / L.

[0092] The rotation speed of the vigorous stirring in S210 is 300 to 1000 rpm / min.

[0093] In S220, the sixth product is taken and subjected to heating and reduction in a mixed gas atmosphere of H2 and an inert gas at a specific concentration to obtain carbon powder (seventh product) having a specific precious metal content.

[0094] Specifically, the specific concentration of H2 in S220 may be a mixed gas of H2 and Ar or H2 and N2 in any ratio.

[0095] The heating rate of the thermal reduction in step S220 is in the range of 1°C / min to 20°C / min, and optionally in the range of 5°C / min to 10°C / min, and the temperature of the thermal reduction is in the range of 200°C to 900°C, and optionally in the range of 300°C to 400°C.

[0096] In S230, a certain amount of the seventh product is taken, washed with pickling solution, and dried to obtain a platinum-containing catalyst.

[0097] Specifically, the pickling solution in S230 contains one or more of nitric acid, perchloric acid, and acetic acid.

[0098] The substance concentration of the pickling solution in S230 is in the range of 0.2 mol / L to 5 mol / L, and optionally in the range of 0.5 mol / L to 2 mol / L.

[0099] It can be understood that the mass transfer capacity of the catalyst layer 400 of a fuel cell is related to the size and type of pores in the carbon material, and during the mass transfer process, the reaction occurs continuously and stably in the cavities and pore channels that are connected to the outside, and the generated water can be discharged in a timely manner to ensure the continuous progress of the reaction. After high-temperature treatment, the organic biomass precursor is thermally decomposed and carbonized, and the corresponding pore structure is formed under the action of the template agent. Under the catalytic action of the metal salt, the molecules of the graphitic microcrystalline layer on the surface are polymerized and rearranged, and the degree of regularity and order continues to improve, tending to graphitize, and finally a porous carbon structure that has been graphitized to a certain extent is formed.

[0100] Specifically, the pore characteristic value

number

number

[0101] In addition to these pores, the carrier material 410 also has several cavities that are not connected to the outer surface and are impermeable to fluids. These cavities do not directly affect the performance of the catalyst layer 400 in the early stages of the electrochemical reaction, and cannot be detected or analyzed by gas adsorption methods. However, under high-potential operating conditions such as start-up and shutdown, the presence of these cavities aggravates corrosion of the carrier material.

[0102] Specifically, the cavity characteristic value

number

number

[0103] In a fourth aspect, the use of the above-mentioned carrier material in a membrane electrode of a fuel cell allows the membrane electrode to have excellent mass transfer capability.

[0104] The present application has an advantageous effect of providing a carrier material and a manufacturing method thereof, which improves the mass transfer resistance of a membrane electrode made of the carrier material by controlling the pore characteristic value and the cavity characteristic value.

[0105] The technical solution of the present application will be further described below with reference to specific examples.

[0106] Example 1 (1) Carbon quantum dots were dispersed in a 10 mg / mL solution of iron nitrate in isopropyl alcohol, and the mixture was stirred in a sealed container at room temperature to obtain a 10 wt.% template agent mixture (Product 1). The volume ratio of water to isopropyl alcohol in the iron nitrate solution was 0.5.

[0107] (2) The first product was collected and dried at low temperature in vacuum at −40° C. to obtain a mixture of template metal salts (second product).

[0108] (3) Heavy oil was added to the second product, and the mixture was stirred in a sealed container at room temperature to obtain a third product, where the mass ratio of the heavy oil to the second product was 0.1.

[0109] (4) Using a KSL-1700L box furnace manufactured by HF-Kejing, the third product was subjected to a first heat treatment under nitrogen conditions, with the heating rate for the first heat treatment being 1°C / min, the temperature being 200°C, and the product was cooled and removed to obtain the fourth product.

[0110] (5) The fourth product was washed with 0.2 mol / L hydrochloric acid solution, purified, filtered and dried to obtain carbon powder (fifth product).

[0111] (6) The fifth product was subjected to a second heat treatment (high-temperature heat treatment) in an argon atmosphere, using a FULLAD graphitization furnace as the equipment. The heating rate of the high-temperature heat treatment was 10°C / min, the temperature was 1600°C, and it was allowed to cool naturally to room temperature. Then, medium-temperature heat treatment was performed in a carbon dioxide atmosphere, the heating rate of the medium-temperature heat treatment was 10°C / min, the temperature was 200°C, and it was allowed to cool to obtain a carrier material. The carrier material in this embodiment was defined as C1.

[0112] (7) The carrier material was placed in a 1 mol / L chloroplatinic acid ethanol solution at a rotation speed of 500 rpm / min, sealed, stirred uniformly, and dried to obtain the sixth product.

[0113] (8) Product 6 was heated and reduced in a H2 (20% Ar) gas atmosphere to obtain Product 7. The equipment used was a BONA tube furnace, and the heating rate for the reduction was set to 5°C / min, with the temperature set to 200°C.

[0114] (9) The seventh product was added to a 1 mol / L hydrochloric acid solution for acid washing and purification, followed by filtration and drying to obtain a platinum-containing catalyst, which was defined as C1-cat in this example.

[0115] Examples 2 to 10 Examples 2 to 10 differ from Example 1 in the mass concentration of the template agent mixture (first product) obtained in (1). Table 1 shows the mass concentrations of the template agent mixtures (first products) in Examples 2 to 10. [Table 1]

[0116] Examples 11 to 19 Examples 11 to 19 differ from Example 1 in the concentration of the iron nitrate mixed solution in isopropyl alcohol in (1). Table 2 shows the concentration of iron nitrate in isopropyl alcohol. [Table 2]

[0117] The test method of the present application will be explained below.

[0118] 1) Test method for specific surface area of ​​carbon materials: At a constant low temperature, an ASAP2460 Micromeritics specific surface area tester was used to measure the gas adsorption amount on the solid surface at different relative pressures, and then the adsorption amount of the sample monolayer was calculated based on the Brunauer-Emmett-Teller adsorption theory and its equation (BET equation), and the specific surface area (SA) of the material was calculated.

[0119] 2) Test method for pore and cavity characteristics: Carrier materials were randomly selected and measured by the Pentapyc TM5200E density tester.

number

number

number

number

number

[0120] 3) Test method for particle size of carrier material: The particle size of the carrier material was tested using a Malvern 3000 laser particle sizer. The intensity distribution of scattered light generated in each direction by particles depends on the particle size, with larger particles having a smaller scattering angle and smaller particles having a larger scattering angle, so the particle size distribution of the particles was obtained using the intensity distribution of scattered light from laser diffraction.

[0121] 4) Test method for platinum content in catalyst: A certain amount of catalyst sample was dissolved in aqua regia, filtered and volumized, and tested for elemental content ICP-Pt by ICP spectrometer.

[0122] 5) Test method for electrochemically active area and retention rate of catalyst: The performance of the catalyst prepared using the carrier material was tested using a three-electrode system. A certain amount of catalyst was weighed out and added in order to a 5% Nafion solution, deionized water, and isopropyl alcohol. The slurry was mixed uniformly using ultrasound. The catalyst loading on the electrode surface was 20 μg / cm. 2 ~50ug / cm 2 The dispersed slurries were then uniformly applied to the surfaces of the disk electrodes, dried, and used as working electrodes. The working electrode, reference electrode, and counter electrode were placed in an electrolytic cell to form a three-electrode system. The reference electrode was a RHE reversible hydrogen electrode, the counter electrode was a large-area Pt sheet, and the electrolyte was a saturated 0.1 M HClO solution.

[0123] A cyclic voltammetry curve test was performed. First, the catalyst was activated at a scan rate of 20 mV / s. After the hydrogen desorption peak area stopped increasing, the potential was scanned 10 times at a rate of 20 mV / s, with the potential scan range being 1.0 V to 1.5 V vs. RHE. After stabilization, the cyclic voltammetry curve was taken, and the hydrogen desorption peak (0.05 V to 0.4 V vs. RHE) was integrated to obtain the area S. The electrochemically active area ECSA was then calculated using Equation 8.

number

number

number

number

number

number

[0124] The working electrode was cycled for 10,000 cycles within the range of 1.0 V to 1.5 V vs. RHE, and the retention rate of the electrochemically active area before and after the cyclic voltammetry test was recorded.

[0125] 6) Test method for mass transport impedance of catalyst layer: The performance of a single cell in which the catalyst layer was made of carbon material was tested using a battery test bench. The catalyst loading on the anode of the membrane electrode used was 0.2 mg / cm. 2 The catalyst loading on the cathode was 0.4 mg / cm 2 After sufficient activation, the impedance test was carried out under the conditions of a battery operating temperature of 80°C, humidity of 100RH%, and battery back pressure of 150kPa / 150kPa, and the current was 2A / cm 2 A load was applied so that the output voltage reached 10000 Hz, and a 10% disturbance current was applied in current control mode at a frequency of 10,000 Hz to 0.5 Hz.

[0126] As shown in FIG. 6, the Nyquist plot obtained from the EIS test was fitted by the equivalent circuit shown in FIG. 6, where the mass transport impedance is represented by a finite Warburg impedance element.

[0127] The detection results of SA, fixed carbon, electrical conductivity, pore characteristic value, cavity characteristic value, ideal density, true density, and compaction density are shown in Table 3.

[0128] The detection results of ICP-Pt, ECSA, ECSA retention rate, and mass transport impedance are shown in Table 4. [Table 3] [Table 4]

[0129] As can be seen from the detection results in Examples 1 to 19 and Tables 3 to 4, the pores in the carrier material are derived from both pore formation by the template agent and pore formation by the catalytic action of the metal salt. In the examples of the present application, the mass concentration of the template agent mixture and the concentration of the metal salt mixture were mainly changed, and the cooperation of these two contributed to the formation of pores / cavities. The pore characteristic values ​​of the obtained carrier materials were 0.15 to 0.52 g / cm. 3 , the cavity characteristic value is about 7 to 60 g / cm 3The achievable ICP-Pt is 46.2-49.2 wt.% and the ECSA is 66.7-96.2 g / cm 3 , ECSA retention rate is 62.54~83.84%, mass transport impedance is 0.553~1.131 2A / cm 2 @Ω.cm 2 By selecting the pore characteristic value and cavity characteristic value suitable for this application based on the predetermined target ECSA retention rate and mass transport impedance, it is possible to express the mass transport capacity of the membrane electrode using the pore characteristic value and cavity characteristic value.

[0130] As can be seen from the detection results of Examples 6 and 9 and Table 4, the specific surface area of ​​Example 6 is 1459.56 m / g and the ECSA is 79.1 m 2 / g, ECSA retention was 62.54%, and mass transport impedance was 1.131 Ω.cm 2 @2A / cm 2 The specific surface area of ​​Example 9 is 1502.91 m / g and the ECSA is 89.5 m 2 / g, ECSA retention was 83.84%, and mass transport impedance was 0.637 Ω.cm 2 @2A / cm 2 Although the carrier materials of Examples 6 and 9 have similar specific surface areas, there are significant differences in the ECSA retention rate and mass transport impedance, which indicates a large difference in mass transport between the membrane electrodes made of the carrier materials.

[0131] By changing the concentration of the template mixture under the same metal salt conditions, the manufactured carrier material contributes to more uniform adhesion of the metal salt to the template, thereby achieving sufficient contact with the carbon source in the first heat treatment process and forming pores or cavities in which a certain amount of template agent is interconnected or adjacent to each other. If the mass concentration of the template mixture is too high, the metal salt may not be dispersed uniformly in the template, resulting in the above-mentioned pore formation process being impossible. If the metal salt acts directly on the carbon source without the intervention of the template agent, a large number of disconnected micropores and cavities will be formed.

[0132] By changing the concentration of the metal salt mixed solution under the condition of the same concentration of template agent, in the second heat treatment process, the metal salt acts as a graphitization catalyst, contributing to improving the stability of the mass transfer process, and the remaining metal salt also acts as a pore-forming agent, connecting some fine micropores to form pores, reducing the proportion of cavity structure and increasing the cavity characteristic value, which contributes to improving the degree of graphitization, and the carrier material has stronger corrosion resistance when used under high-voltage operating conditions such as start-up and shutdown.

[0133] As can be seen from the detection results of Examples 1 to 19, Table 4 and Figure 7, there is a certain rule between the pore characteristic value and mass transport impedance of the carrier material prepared according to the present invention. As the pore characteristic value increases, the mass transport impedance also tends to increase accordingly. However, due to the existence of mutations in the change process, further screening of the pore characteristic value was carried out, and the pore characteristic value was found to be in the range of 0.25 to 0.45 g / cm. 3 When the pore characteristic value is in the range of 0.45 g / cm, a carrier material with high mass transport impedance can be obtained, and the mass transfer capacity of the membrane electrode is good. 3 If the pore characteristic value exceeds 0.25 g / cm, the mass transport impedance increases sharply, the current density in the membrane electrode polarization curve decreases rapidly, and the power density of the membrane electrode decreases. 3 If it is smaller, the change in mass transport impedance is not significant enough.

[0134] As can be seen from the detection results of Examples 1 to 19, Table 4, and FIG. 8, there is a certain rule between the cavity characteristic value and the ECSA retention rate of the carrier material prepared according to the present invention. As the cavity characteristic value increases, the ECSA retention rate tends to increase first and then gradually decrease. Therefore, the preferred range of the cavity characteristic value is 10 to 50 g / cm. 3 is.

[0135] In summary, the mass transfer capacity of a membrane electrode is related to the size and type of pores in the carbon material. During the mass transfer process, the cavities and pore channels connected to the outside allow the reaction to occur continuously and stably, and the generated water can be discharged in a timely manner to ensure the continuous progress of the reaction. The organic biomass precursor, which is treated at high temperatures, is thermally decomposed and carbonized, and the corresponding pore structure is formed under the action of the template agent. Under the catalytic action of metal salts, the molecules of the graphitic microcrystalline layer on the surface polymerize and rearrange, continuously improving the degree of regularity and order, leading to a tendency toward graphitization. Finally, a porous carbon structure with a certain degree of graphitization is formed, resulting in a membrane electrode with excellent mass transfer capacity.

[0136] The above describes in detail the carrier material and the manufacturing method thereof provided by the examples of the present application. In the present text, specific examples are used to explain the principles and embodiments of the present application. However, the explanation of the above examples is only used to understand the method and the gist of the present application. Furthermore, for those skilled in the art, the gist of the present application may cause changes in the form for implementing the invention and the scope of application. In summary, the contents of this specification should not be understood as limiting the present application. [Explanation of symbols]

[0137] 100: Plate 200: Diffusion layer 300: Proton membrane 400: Catalyst layer 410: Carrier materials 420: Catalytic particles

Claims

1. 1. A method for producing a carrier material, comprising: Dispersing a template agent in a metal salt mixture solution to obtain a first product at a specific concentration; low-temperature vacuum drying the first product to obtain a second product; mixing an organic carbon source with the second product to obtain a third product; performing a first heat treatment on the third product under vacuum or inert gas conditions to obtain a fourth product; washing the fourth product with an acid pickling solution and drying to obtain a fifth product; and performing a second heat treatment on the fifth product to obtain the carrier material; the template agent comprises one or more of carbon quantum dots, nano aluminum oxide, nano silicon oxide, nano magnesium oxide, nano calcium oxide, and nano calcium carbonate; The fine particles of the carrier material are configured to have a plurality of pores and a plurality of cavities, the pores being in communication with the outside of the fine particles, and the cavities being isolated from the outside of the fine particles; When the ratio of the mass of the carrier material to the total volume of the pores is defined as a pore characteristic value and the ratio of the mass of the carrier material to the total volume of the cavities is defined as a cavity characteristic value, the pore characteristic value of the carrier material is smaller than the cavity characteristic value of the carrier material. A method for producing a carrier material.

2. The pore characteristic value of the carrier material is 0.250 g / cm ３ ~0.450g / cm ３ and / or the cavity characteristic value of the carrier material is in the range of 10.00 g / cm ３ ~50.00g / cm ３ Contains values ​​in the range A method for producing the carrier material of claim 1 .

3. The metal salt in the metal salt mixed solution includes one or more of iron nitrate, chromium nitrate, cobalt nitrate, nickel nitrate, zinc nitrate, magnesium nitrate, iron chloride, cobalt chloride, nickel chloride, zinc chloride, magnesium chloride, iron sulfate, iron sulfate, iron sulfate, zinc sulfate, and magnesium sulfate; The mixed solvent in the metal salt mixed solution includes a mixture of one or more of isopropyl alcohol, ethylene glycol, n-butanol, N-methylpyrrolidone, and ethanol with distilled water; The solution concentration of the metal salt mixed solution is in the range of 10 mg / mL to 100 mg / mL, and the concentration of the first product of the specific concentration is in the range of 10 wt. % to 50 wt. %. A method for producing the carrier material of claim 1 .

4. the organic carbon source comprises one or more of asphalt, sugar, heavy oil, fatty acid, polyvinyl alcohol, polyamide, epoxy resin, phenolic resin, organic salt, and derivatives thereof; In the step of mixing the organic carbon source with the second product to obtain a third product, the mass ratio of the organic carbon source to the second product comprises a value in the range of 0.1 to 3; A method for producing the carrier material of claim 1 .

5. In the step of performing a first heat treatment on the third product under vacuum or inert gas conditions to obtain a fourth product, the temperature rise rate of the first heat treatment includes a value within a range of 1°C / min to 20°C / min, and the heat treatment temperature includes a value within a range of 200°C to 1000°C. A method for producing the carrier material of claim 1 .

6. the pickling solution contains one or more of hydrochloric acid, nitric acid, perchloric acid, sulfuric acid, acetic acid, and hydrofluoric acid; The substance concentration of the pickling solution includes a value in the range of 0.2 mol / L to 5 mol / L; A method for producing the carrier material of claim 1 .

7. The step of subjecting the fifth product to a second heat treatment to obtain the carrier material includes: heat-treating the fifth product at a high temperature in an inert atmosphere to obtain an intermediate product; cooling the intermediate product; and subjecting the cooled intermediate product to a medium-temperature heat treatment in an oxidizing atmosphere to obtain the carrier material. The temperature rise rate of the high-temperature heat treatment includes a value in the range of 1°C / min to 15°C / min, and the heat treatment temperature includes a value in the range of 1000°C to 3000°C, and the temperature rise rate of the medium-temperature heat treatment includes a value in the range of 1°C / min to 15°C / min, and the heat treatment temperature includes a value in the range of 100°C to 600°C. A method for producing the carrier material according to any one of claims 1 to 6.

8. A carrier material comprising: The fine particles of the carrier material are configured to have a plurality of pores and a plurality of cavities, the pores being in communication with the outside of the fine particles, and the cavities being isolated from the outside of the fine particles; The ratio of the mass of the carrier material to the total volume of the pores is defined as a pore characteristic value; When the ratio of the mass of the carrier material to the total volume of the cavity is defined as a cavity characteristic value, The pore characteristic value of the carrier material is smaller than the cavity characteristic value of the carrier material. Carrier material.

9. The pore characteristic value of the carrier material is 0.250 g / cm ３ ~0.450g / cm ３ and / or the cavity characteristic value of the carrier material is in the range of 10.00 g / cm ３ ~50.00g / cm ３ Contains values ​​in the range The carrier material of claim 8.

10. The specific surface area of ​​the carrier material is 400 m ２ / g~1500m ２ / g, and / or The particle size of the carrier material includes values ​​in the range of 100 nm to 2 μm; and / or the compaction density of the carrier material comprises a value within the range of 0.05 g / mL to 0.80 g / mL; the conductivity of the carrier material comprises values ​​in the range of 6.4 S / cm to 26.5 S / cm; the fixed carbon content of the carrier material includes values ​​within the range of 84.5% to 97.2%; The carrier material of claim 8.

11. A fuel cell comprising the carrier material according to any one of claims 8 to 10.

12. Use of a carrier material according to any one of claims 8 to 10 in a membrane electrode of a fuel cell.

Images