CN113725449A - Fuel cell catalyst, preparation method and application thereof - Google Patents

Fuel cell catalyst, preparation method and application thereof Download PDF

Info

Publication number
CN113725449A
CN113725449A CN202010447365.4A CN202010447365A CN113725449A CN 113725449 A CN113725449 A CN 113725449A CN 202010447365 A CN202010447365 A CN 202010447365A CN 113725449 A CN113725449 A CN 113725449A
Authority
CN
China
Prior art keywords
fuel cell
nico
carbon particles
cell catalyst
silicon source
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010447365.4A
Other languages
Chinese (zh)
Other versions
CN113725449B (en
Inventor
符冬菊
朱子岳
陈建军
叶利强
田勇
张维丽
傅婷婷
张莲茜
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen Research Institute Tsinghua University
Original Assignee
Shenzhen Research Institute Tsinghua University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenzhen Research Institute Tsinghua University filed Critical Shenzhen Research Institute Tsinghua University
Priority to CN202010447365.4A priority Critical patent/CN113725449B/en
Publication of CN113725449A publication Critical patent/CN113725449A/en
Application granted granted Critical
Publication of CN113725449B publication Critical patent/CN113725449B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material
    • H01M4/9075—Catalytic material supported on carriers, e.g. powder carriers
    • H01M4/9083—Catalytic material supported on carriers, e.g. powder carriers on carbon or graphite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M12/00—Hybrid cells; Manufacture thereof
    • H01M12/04—Hybrid cells; Manufacture thereof composed of a half-cell of the fuel-cell type and of a half-cell of the primary-cell type
    • H01M12/06—Hybrid cells; Manufacture thereof composed of a half-cell of the fuel-cell type and of a half-cell of the primary-cell type with one metallic and one gaseous electrode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/88—Processes of manufacture
    • H01M4/8825—Methods for deposition of the catalytic active composition
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material
    • H01M4/9016—Oxides, hydroxides or oxygenated metallic salts
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M2004/8678—Inert electrodes with catalytic activity, e.g. for fuel cells characterised by the polarity
    • H01M2004/8689—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Abstract

The invention discloses a fuel cell catalyst and a preparation method and application thereof. The fuel cell catalyst is of a core-shell structure, a core body of the core-shell structure is carbon particles, Co and N are doped in the carbon particles, and cavities are formed in the carbon particles; the shell layer of the core-shell structure coats the core body and grows on the surface of the core body, and the shell layer is made of NiCo2O4. The fuel cell catalyst has excellent structural stability and large specific surface area, and provides more active sites for catalytic reaction; the NiCo2O4Growth of shellThe porous carbon particles can be fully contacted with electrolyte on the surfaces, and electron transfer and energy transportation are promoted. The preparation method of the fuel cell catalyst can ensure that the prepared fuel cell catalyst has stable structural morphology and catalytic performance, is environment-friendly and energy-saving, has low cost and is easy for industrialization.

Description

Fuel cell catalyst, preparation method and application thereof
Technical Field
The invention belongs to the field of fuel cells, and particularly relates to a fuel cell catalyst, and a preparation method and application thereof.
Background
With the exhaustion of resources and the increasing environmental pollution of traditional fossil fuels, the development of storage and conversion devices for green and efficient renewable energy and new energy is urgent. The zinc-air battery is a special fuel battery, and has the advantages of high theoretical energy density, safety, portability, greenness, no pollution and the like, however, the catalytic efficiency of the fuel battery, especially the zinc-air battery, in the cathode oxygen reduction reaction is low, and the commercial development of the fuel battery, especially the zinc-air battery, is greatly limited. Currently, most of the cathode catalysts used in commercial applications are noble metals, such as Pt/C and RuO2And the disadvantages of high cost, scarcity, poor stability and the like of the noble metal prevent the wide popularization of the fuel cells such as zinc air and the like. Therefore, it is important to develop a non-noble metal catalyst having catalytic performance equivalent to that of a noble metal catalyst.
To reduce costs, non-noble metal catalysts are currently emerging. Among the numerous non-noble metal catalysts, spinel type NiCo2O4The transition metal oxide with mixed valence has the cost far lower than that of noble metal, has more flexible structure regulation and control, and attracts more and more researchers. However, spinel-type NiCo has been shown to be less conductive and have insufficient active sites due to its tendency to agglomerate, poor conductivity and insufficient active sites2O4Is limited in the oxygen reduction reaction. To improve their performance, they are also usedHigh performance spinel type NiCo is appeared2O4Composite materials, but found in practice, spinel type NiCo2O4The composite material still has the defects of easy agglomeration, poor conductivity, active sites and the like, so that the catalytic activity of the composite material still needs to be improved. Moreover, spinel type NiCo is currently prepared2O4Common methods for materials include a coprecipitation method, a hydrothermal method, an electrochemical deposition method and the like, but the methods are complex to operate and are not beneficial to large-scale production.
Disclosure of Invention
The present invention is directed to overcoming the above-mentioned disadvantages of the prior art, and provides a fuel cell catalyst and a method for preparing the same, which solves the problems of the prior spinel-type NiCo2O4The catalyst has the technical problems of easy agglomeration, poor conductivity, insufficient active sites and the like.
It is another object of the present invention to provide a fuel cell cathode and a fuel cell including the same, which solves the problems of the conventional spinel-type NiCo2O4The catalytic activity of the catalyst is not ideal, so that the electrochemical performance of the fuel cell is not ideal.
In order to achieve the above object, according to one aspect of the present invention, a fuel cell catalyst is provided. The fuel cell catalyst is of a core-shell structure, a core body of the core-shell structure is carbon particles, Co and N are doped in the carbon particles, and cavities are formed in the carbon particles; the shell layer of the core-shell structure coats the core body and grows on the surface of the core body, and the shell layer is made of NiCo2O4。
In another aspect of the present invention, a method of preparing a fuel cell catalyst is provided. The preparation method of the fuel cell catalyst comprises the following steps:
dissolving a dispersing agent and 2-methylimidazole, and adding a nanoscale silicon source template for dispersion treatment to obtain a dispersion liquid containing the silicon source template; adding a soluble cobalt salt solution into the dispersion liquid, and carrying out mixing treatment and precipitation reaction to obtain first composite nano particles of the ZIF-67-coated silicon source template;
dispersing the first composite nano particles in a soluble nickel salt solution, mixing, and then carrying out solid-liquid separation to obtain second composite nano particles with a plurality of NiCo-LDH growing on the surfaces of the first composite nano particles;
calcining the second composite nanoparticles in an inert atmosphere to form NiCo-LDH into NiCo2O4The coating layer and the first composite nano particles are generated into carbon particles which are embedded with the nanoscale silicon source template and Co and N codoped, and the carbon particles are marked as third composite nano particles;
and (3) carrying out reaction treatment on the third composite nano particles in a strong alkali solution to remove the nano silicon source template.
In yet another aspect of the present invention, a fuel cell cathode is provided. The fuel cell cathode contains the fuel cell catalyst of the present invention or a fuel cell catalyst prepared by the fuel cell catalyst preparation method of the present invention.
In yet another aspect of the present invention, a fuel cell is provided. The fuel cell includes a metal cathode that is the fuel cell cathode of the present invention.
Compared with the prior art, the invention has the following technical effects:
the fuel cell catalyst has excellent structural stability, large specific surface area and rich catalytic reaction active sites, and the NiCo contained in the catalyst2O4The shell layers 3 are uniformly distributed, thereby effectively fixing NiCo2O4The distribution of (A) avoids NiCo2O4The aggregation can be fully contacted with the electrolyte, the electron transfer and the energy transportation are promoted, and the catalytic activity is high.
According to the preparation method of the fuel cell catalyst, on one hand, the nanoscale silicon source template is uniformly dispersed in the presence of the dispersing agent, so that the nanoscale silicon source template can be uniformly dispersed in the first composite nanoparticles, carbon particles are endowed with a porous structure after the treatment of removing the silicon source template, and the uniformity of porous distribution is improved; and is etched on the surface of the first composite nanometer particle by nickel ionsGrowing NiCo-LDH nano-sheets in situ on the surface and directly growing NiCo in situ in the subsequent heat treatment2O4The nano-sheets effectively ensure the growth of NiCo2O4Poor agglomeration of the nanosheets occurs. Therefore, the fuel cell catalyst material prepared by the preparation method has excellent structural stability, large specific surface area and rich catalytic reaction active sites; and contains NiCo2O4The nano-sheets are uniformly distributed, and NiCo is effectively avoided2O4Thereby imparting to the fuel cell catalyst material sufficient contact with the electrolyte to facilitate electron transfer and energy transport.
The cathode of the fuel cell and the fuel cell of the invention are obviously improved in electrochemical performance because the cathode of the fuel cell comprises the fuel cell catalyst of the invention.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic diagram of the structure of a fuel cell catalyst according to an embodiment of the present invention;
FIG. 2 is a schematic process flow diagram of a method for preparing a fuel cell catalyst according to an embodiment of the present invention;
FIG. 3 is SiO that is provided in example 1 of the present invention2Scanning Electron Microscope (SEM) picture of @ ZIF-67@ NiCo-LDH precursor;
FIG. 4 is a diagram of Co, N-C @ NiCo provided in example 1 of the present invention2O4Electrochemical polarization profile of fuel cell catalyst.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting, and that all other embodiments that can be made by one of ordinary skill in the art based on the embodiments described herein will fall within the scope of the invention without inventive faculty.
In one aspect, embodiments of the present invention provide a fuel cell catalyst. The fuel cell catalyst is of a core-shell structure, the structure of the fuel cell catalyst is shown in figure 1, and a core body 1 of the core-shell structure is hollow carbon particles, and the core body 1 is also carbon particles with cavities 2 inside. The core body 1 is provided with both the carbon particles and the hollow structure, so that the hollow carbon particles give the core body 1 a large specific surface area, provide favorable sites for physical and chemical reactions, and provide more active sites for adsorption of oxygen molecules. And the graphitization degree of the hollow carbon particles is higher, so that the conductivity of the fuel cell catalyst material can be obviously improved. In one embodiment, the diameter of the hollow carbon particles is 200 to 400nm, or the diameter of the cavity 2 is further controlled to be 100 to 200 nm. Through optimizing the hollow carbon particle is also the core body 1 and the diameter of cavity 2, can further improve the specific surface area of core body 1, richen active site and strengthen its electric conductive property.
Preferably, the hollow carbon particles are also hollow carbon particles in which the core body 1 is formed of a mesoporous carbon material, and thus, the hollow carbon particles have a rich porous structure and are relatively uniformly porous. Mesoporous carbon is used as a material of the hollow carbon core body 1, so that the fuel cell catalyst is endowed with a large specific surface area, and the conductivity of the fuel cell catalyst is improved. In one embodiment, the mesoporous carbon has a pore size of 5 to 30 nm. By optimizing the pore size, the specific surface area and the enhanced active sites of the fuel cell catalyst can be further increased, and the full contact with the electrolyte can be enhanced.
The hollow carbon particles, preferably the carbon material, preferably the mesoporous carbon material, are further doped with a Co element and an N element. In one embodiment, the Co is doped in the hollow carbon particles in an amount of 4 to 6 at%, and the N is doped in the hollow carbon particles in an amount of 2 to 4 at%. Co and N are doped in the hollow carbon particles to form a unique Co-Nx-C structure which has high dispersity and a synergistic unsaturated environment, the charge transfer effect is enhanced by the interaction between a Co active center and a carbon carrier, and the oxygen adsorption capacity is improved by the unique electronic structure formed by N and carbon, so that the four-electron reaction is promoted and the catalytic activity of the catalyst is improved.
The shell layer 3 of the core-shell structure coats the core body 1, specifically, the shell layer grows on the surface of the core body 1 to form a coating layer, and the shell layer 3 is made of NiCo2O4. In one embodiment, the shell 3 is made of NiCo2O4Nanosheet composition, and the NiCo2O4The nanoplatelets are grown on the surface of the core body 1, as shown in figure 1, and both the shell 3 and preferably the core body 1 are completely coated. Of course, it may be possible to use a NiCo coating without complete coating2O4The nanoplatelets can be in a plurality of sheets forming the cladding layer. Wherein the NiCo2O4The nanosheets may be grown conforming to the surface shape of the core body 1. Thus NiCo2O4The growth of the coating layer on the surface of the core body 1 effectively avoids the growth of NiCo2O4Preferably NiCo2O4The nano-sheets are agglomerated, so that the catalytic activity is improved. In one embodiment, the shell 3 is preferably NiCo2O4The thickness of the nano-sheet is 20-100, such as 20-50 nm.
Based on the fuel cell catalyst structure described above, the fuel cell catalyst may be represented as Co, N-C @ NiCo2O4. Where @ denotes a coating (hereinafter referred to as @, which also means a coating), Co, N-C denotes Co, N-doped hollow carbon particle core 1; the NiCo2O4Is a shell layer 3 which is coated on the surface of the Co, N-C nucleus body 1. Therefore, the fuel cell catalyst described in each of the above examples has excellent structural stability, a large specific surface area, a rich catalytic reaction active site, and the NiCo contained therein2O4The shell layer 3 is uniformly distributed and effectively fixes NiCo2O4Avoids agglomeration thereof and improves the fuel cell catalyst and electricityThe sufficient contact of the electrolyte promotes the electron transfer and the energy transportation, and effectively improves the catalytic activity of the fuel cell catalyst.
Correspondingly, the embodiment of the invention also provides a preparation method of the fuel cell catalyst. The process flow of the preparation method of the fuel cell catalyst is shown in figure 2, and is combined with figure 1, and the preparation method comprises the following steps:
s01, preparing a first composite nanoparticle of a ZIF-67 coated silicon source template:
dissolving a dispersing agent and soluble cobalt salt, and adding a nano-scale silicon source template for dispersion treatment to obtain a dispersion liquid containing the silicon source template; adding a 2-methylimidazole solution into the dispersion liquid, and carrying out mixing treatment and precipitation reaction to obtain first composite nanoparticles of a ZIF-67-coated silicon source template;
s02, preparing a second composite nanoparticle with NiCo-LDH nanosheets growing on the surface of the first composite nanoparticle:
dispersing the first composite nano particles in a soluble nickel salt solution, mixing, and then carrying out solid-liquid separation to obtain second composite nano particles with a plurality of NiCo-LDH growing on the surfaces of the first composite nano particles;
s03, calcining the second composite nanoparticles:
calcining the second composite nanoparticles in an inert atmosphere to form NiCo-LDH into NiCo2O4The coating layer and the first composite nano particles are generated into carbon particles which are embedded with the nanoscale silicon source template and Co and N codoped, and the carbon particles are marked as third composite nano particles;
s04, carrying out strong base etching treatment on the third composite nano particles:
and (3) carrying out reaction treatment on the third composite nano particles in a strong alkali solution to remove the nano silicon source template.
In step S01, the dispersing agent is added to the dispersion liquid to uniformly disperse the nano-silicon source template and prevent nano SiO2Agglomerating to form a uniformly dispersed dispersion. In one embodiment, the dispersant comprises a dodecyl sulfonic groupSodium acid, commercial nano SiO2At least one of a special dispersant and a coupling agent KH570, wherein the addition amount of the dispersant can be added according to the addition amount of a conventional dispersant, and the addition amount of the dispersant is used for at least ensuring that the nano silicon source template is uniformly dispersed; the nano-scale silicon source template can be SiO2Particles, preferably carboxy-modified nano-SiO2The particle size of the nano silicon source template can be 100-200 nm; the solvent comprises at least one of methanol, ethanol, or deionized water.
After the 2-methylimidazole solution is added into the dispersion liquid, a ZIF-67 framework structure material can be formed by the dispersion liquid and soluble cobalt salt, and a plurality of nanoscale silicon source templates are coated by the ZIF-67 material, namely the nanoscale silicon source template @ ZIF-67 nano composite material is formed. For example, when the nano-scale silicon source template is SiO2In the process, the nano silicon source template @ ZIF-67 nano composite material is formed and can be marked as SiO2@ ZIF-67, e.g. SiO2@ ZIF-67 denotes ZIF-67 coating SiO2. In order to etch the hollow carbon particles formed in step S04, in one embodiment, the mass ratio of the silicon source template to the dissolved 2-methylimidazole contained in the dispersion is (2-4): 1-2. Wherein "()" here and elsewhere throughout the text means the mass ratio range and includes endpoints such as (1-2) means the range of 1-2. Preferably, the mixing ratio of the two is controlled, so that the generated nanoscale silicon source template @ ZIF-67 nano composite material such as SiO2The particle size of @ ZIF-67 is preferably 400 to 600 nm.
In another embodiment, the soluble cobalt salt solution is prepared by mixing a soluble cobalt salt and 2-methylimidazole in a molar ratio of 1: (4-8) to the dispersion. In a particular embodiment, the soluble cobalt salt comprises at least one of cobalt nitrate, cobalt sulfate, cobalt acetate. In order to improve the efficiency of the mixing process and the precipitation reaction, the mixing process may be, but not limited to, magnetic stirring, and in a specific embodiment, the mixing process is magnetic stirring at normal temperature for 2 to 6 hours. After the precipitation reaction is finished, carrying out solid-liquid separation on the precipitate, drying the collected precipitate, for example, centrifuging the precipitate, collecting the precipitate, and then carrying out vacuum drying for 12h at the temperature of 60 ℃.
In step S02, after the first composite nanoparticle obtained in step S01 is dispersed in a soluble nickel salt solution, a plurality of NiCo-LDHs are grown in situ on the surface of the first composite nanoparticle by nickel ion etching, and a plurality of NiCo-LDHs form a coating layer to coat the first composite nanoparticle, so as to obtain a second composite nanoparticle in which a plurality of NiCo-LDHs are grown on the surface of the first composite nanoparticle, that is, a nano-scale silicon source template @ ZIF-67@ NiCo-LDH, specifically, SiO, is obtained2@ ZIF-67@ NiCo-LDH. Wherein NiCo-LDH represents layered Ni, Co double metal hydroxide. The NiCo-LDH may be grown conforming to a surface shape of the first composite nanoparticle. In one embodiment, the soluble nickel salt solvent is prepared by mixing a soluble cobalt salt contained in the soluble cobalt salt solvent and a soluble nickel salt contained in the soluble nickel salt solvent in a molar ratio of 1: (0.5-2) is mixed with the first composite nanoparticles. In a specific embodiment, the soluble nickel salt comprises at least one of nickel nitrate, nickel sulfate, and nickel acetate. In order to improve the efficiency of the mixing process, the mixing process may be, but not limited to, magnetic stirring, and in a specific embodiment, the mixing process is magnetic stirring at normal temperature for 10min to 30 min. Performing solid-liquid separation, collecting precipitate, drying, centrifuging the precipitate, collecting precipitate, and vacuum drying at 60 deg.C for 12 hr.
In step S03, after the second composite nanoparticles obtained in step S02 are calcined in an inert atmosphere, the ZIF-67 in the first composite nanoparticles are carbonized to generate Co-and N-doped carbon particles, specifically, the first composite nanoparticles are calcined to generate Co-and N-doped carbon particles embedded with the nano-scale silicon source template, i.e., to generate a precursor of the core body 1 shown in fig. 1. Since Co and N Co-doped carbon particles are generated by carbonizing ZIF-67, the Co and N Co-doped carbon particles are preferably mesoporous carbon and have a rich porous structure. The NiCo-LDH produces NiCo2O4The nano-coating, i.e. the shell 3 as shown in fig. 1, is created. In one embodiment, the calcination treatment is toHeating to 500-800 ℃ at the speed of 1-5 ℃/min, and preserving heat for 2-4 h. In another embodiment, the inert atmosphere may be an inert atmosphere constructed from at least one gas of nitrogen or argon.
In step S04, after the third composite nanoparticle obtained in step S03 is subjected to a reaction treatment in a strong alkali solution, the template of the nanoscale silicon source contained in the third composite nanoparticle is etched by the strong alkali to remove the cavity 2 contained in the carbon particle as shown in fig. 1, i.e., the Co-and N-doped carbon particle core body 1 as shown in fig. 1 is formed. Thus, after a strong base etching treatment, the Co, N-C @ NiCo described above is produced2O4. In one embodiment, the alkali solution is 0.5-2 mol/mL of NaOH solution, and the temperature of the third composite nanoparticles reacting in the alkali solution is 60-80 ℃. And (3) carrying out solid-liquid separation after the strong base etching treatment, washing and drying the collected filter residue, such as washing for 3-6 times by using absolute ethyl alcohol or deionized water, and finally carrying out vacuum drying for 12 hours at the temperature of 60 ℃.
Therefore, the fuel cell catalyst preparation method described above can prepare the Co, N doped hollow carbon particle core 1 having the cavity 2, preferably the carbon material of the hollow carbon particle core 1 is mesoporous carbon having a rich porosity, and NiCo is grown in situ on the surface of the hollow carbon particle core 12O4The nano-sheet coating layer 3 endows the prepared fuel cell catalyst material with excellent structural stability, large specific surface area, rich catalytic reaction active sites, high catalytic activity and NiCo2O4The nano sheets are uniformly distributed, so that the fuel cell catalyst material can be fully contacted with electrolyte, and electron transfer and energy transportation are promoted. In addition, the preparation method of the fuel cell catalyst has controllable process conditions, can ensure that the prepared fuel cell catalyst has stable structural form and catalytic performance, is environment-friendly and energy-saving, has low cost and is easy to industrialize.
On the other hand, based on the fuel cell catalyst and the preparation method thereof, the embodiment of the invention also provides a fuel cell cathode and a fuel cell comprising the fuel cell cathode. Wherein the fuel cell cathode structure may be conventional for a fuel cell cathode except that the fuel cell cathode further contains the fuel cell catalyst described above. In a preferred embodiment, the fuel cell cathode is a metal air cell cathode, such as specifically a zinc air cell cathode. Since the fuel cell cathode contains the fuel cell catalyst described above, the fuel cell cathode is high in catalytic activity.
The fuel cell includes a metal cathode and, of course, other components necessary for the fuel cell. Wherein, the metal cathode is the cathode of the fuel cell of the embodiment of the invention. Preferably, therefore, the fuel cell is a metal fuel cell, in particular a zinc-air cell. Thus, the electrochemical performance of the fuel cell is obviously improved.
The fuel cell catalyst of the embodiments of the present invention, its preparation method and application, etc. are illustrated by a plurality of specific examples below.
Example 1
This example provides a Co, N-C @ NiCo2O4A fuel cell catalyst and a method for preparing the same. The Co, N-C @ NiCo2O4The preparation method of the fuel cell catalyst comprises the following specific steps:
s11: 0.2g of nano SiO with a diameter of 200nm2The powder, 0.02g of coupling agent KH570 and 24mol of 2-methylimidazole are put into 100ml of methanol solution and stirred evenly to obtain stable suspension solution 1; dissolving 4mol of cobalt nitrate hexahydrate in 100ml of methanol solution, and fully and uniformly stirring to obtain a stable solution 2; mixing the suspension solution 1 and the solution 2, magnetically stirring for 3h, centrifuging, collecting precipitate, washing with methanol, and vacuum drying at 60 deg.C for 12h to obtain SiO2@ ZIF-67 template;
s12: SiO obtained in step S112@ ZIF-67 template is dispersed in ethanol containing 4mol nickel nitrate hexahydrate, magnetically stirred at normal temperature for 15min, centrifuged to collect precipitate, and vacuum dried at 60 deg.C for 12h to obtain SiO2@ ZIF-67@ NiCo-LDH precursor;
s13: SiO obtained in step S122@ ZIF-67@ NiCo-LDH precursor is placed in a tube furnace, a gas flow bottle valve is opened, nitrogen with the flow of 100sccm is introduced, the temperature is raised to 700 ℃ at the speed of 2 ℃/min, the temperature is kept for 4h under the condition, the whole reaction system is cooled to the room temperature under the nitrogen atmosphere, and NiCo is obtained2O4Nano SiO embedded in nano sheet coating2Co-doping Co and N with the carbon microsphere composite material;
s14: the NiCo obtained in the step S132O4Nano SiO embedded in nano sheet coating2The Co and N codoped carbon microsphere composite material is placed in 1.5mol/mL NaOH solution, reacts in a water bath at 70 ℃ for 6 hours, is washed with absolute ethyl alcohol for 4 times, and is finally dried in vacuum at 60 ℃ for 12 hours to obtain Co, N-C @ NiCo2O4A composite material.
Example 2
This example provides a Co, N-C @ NiCo2O4A fuel cell catalyst and a method for preparing the same. The Co, N-C @ NiCo2O4The preparation method of the fuel cell catalyst comprises the following specific steps:
s11: 0.2g of nano SiO with a diameter of 100nm2Putting the powder, 0.1g of sodium dodecyl sulfonate and 16mol of 2-methylimidazole in 100ml of methanol solution, and fully and uniformly stirring to obtain a stable suspension solution 1; dissolving 4mol of cobalt acetate in 100ml of methanol solution, and fully and uniformly stirring to obtain a stable solution 2; mixing solution 1 and solution 2, magnetically stirring for 4h, centrifuging, collecting precipitate, washing with methanol, and vacuum drying at 60 deg.C for 12h to obtain SiO2@ ZIF-67 template;
s12: SiO obtained in step S112@ ZIF-67 template is dispersed in ethanol containing 4mol of nickel acetate, magnetically stirred at normal temperature for 20min, centrifuged to collect precipitate, and vacuum dried at 60 deg.C for 12h to obtain SiO2@ ZIF-67@ NiCo-LDH precursor;
s13: SiO obtained in step S122@ ZIF-67@ NiCo-LDH precursor is placed in a tube furnace, a gas flow bottle valve is opened, nitrogen with the flow of 80sccm is introduced, the temperature is increased to 600 ℃ at the speed of 5 ℃/min, the temperature is kept for 3h under the condition, and the whole reaction system is subjected to nitrogen treatmentCooling to room temperature in the atmosphere of gas to obtain NiCo2O4Nano SiO embedded in nano sheet coating2Co-doping Co and N with the carbon microsphere composite material;
s14: the NiCo obtained in the step S132O4Nano SiO embedded in nano sheet coating2The Co and N codoped carbon microsphere composite material is placed in 1mol/mL NaOH solution, reacts in a water bath at the temperature of 80 ℃ for 8 hours, is washed by absolute ethyl alcohol for 4 times, and is finally dried in vacuum at the temperature of 60 ℃ for 12 hours to obtain Co, N-C @ NiCo2O4A composite material.
Example 3
This example provides a Co, N-C @ NiCo2O4A fuel cell catalyst and a method for preparing the same. The Co, N-C @ NiCo2O4The preparation method of the fuel cell catalyst comprises the following specific steps:
s11: 0.2g of nano SiO with a diameter of 200nm2The powder, 0.02g of coupling agent KH570 and 32mol of 2-methylimidazole are put into 100ml of methanol solution and stirred evenly to obtain stable suspension solution 1; dissolving 4mol of cobalt sulfate in 100ml of methanol solution, and fully and uniformly stirring to obtain a stable solution 2; mixing solution 1 and solution 2, magnetically stirring for 6h, centrifuging, collecting precipitate, washing with methanol, and vacuum drying at 60 deg.C for 12h to obtain SiO2@ ZIF-67 template;
s12: SiO obtained in step S112@ ZIF-67 template is dispersed in ethanol containing 4mol of nickel sulfate, magnetically stirred for 10min at normal temperature, centrifuged to collect precipitate, and vacuum dried at 60 deg.C for 12h to obtain SiO2@ ZIF-67@ NiCo-LDH precursor;
s13: SiO obtained in step S122@ ZIF-67@ NiCo-LDH precursor is placed in a tube furnace, a gas flow bottle valve is opened, nitrogen with the flow of 80sccm is introduced, the temperature is raised to 800 ℃ at the speed of 5 ℃/min, the temperature is kept for 2h under the condition, the whole reaction system is cooled to room temperature under the nitrogen atmosphere, and NiCo is obtained2O4Nano SiO embedded in nano sheet coating2Co-doping Co and N with the carbon microsphere composite material;
s14: the NiCo obtained in the step S132O4Nano sheet coating and embeddingWith nano SiO2The Co and N codoped carbon microsphere composite material is placed in 2mol/mL NaOH solution, reacts in a water bath at the temperature of 60 ℃ for 4 hours, is washed by absolute ethyl alcohol for 4 times, and is finally dried in vacuum at the temperature of 60 ℃ for 12 hours to obtain Co, N-C @ NiCo2O4A composite material.
Fuel cell embodiment
The fuel cell catalysts provided in examples 1 to 3 above and the catalysts provided in comparative examples were prepared as air cathodes, respectively, as follows:
5mg of the Co, N-C @ NiCo provided in examples 1 to 3, respectively, were taken2O4The fuel cell catalyst was dispersed in 1mL of deionized water-ethanol (V water: V ethanol 4:1) solution, and then 50 μ l nafion (5 wt.%) solution was added to the solution for ultrasonication to uniformly disperse the material and form a catalyst layer (the catalyst content per unit area of the fuel cell catalyst was 1.0mg cm) on the surface of the hydrophobic carbon paper-2)。
Assembling the prepared air cathode into a zinc-air battery according to the zinc-air battery; wherein, 0.2M Zn (CH)3COO)2The 6.0M KOH solution of (c) as an electrolyte and the high purity zinc foil can be used as an anode, respectively.
Correlation characteristic test
SiO as provided in examples 1 to 3 above2@ ZIF-67@ NiCo-LDH precursor and Co, N-C @ NiCo2O4The fuel cell catalysts were each subjected to Scanning Electron Microscopy (SEM) analysis, wherein the SiO provided in example 12SEM of @ ZIF-67@ NiCo-LDH precursor As shown in FIG. 3, it can be seen from FIG. 3 that SiO provided in example 12The @ ZIF-67@ NiCo-LDH precursor is approximately spherical, the size of the precursor is 250-500 nm, and the rough surface morphology of the precursor indicates the successful growth of the NiCo-LDH. In addition, SiO of other examples was measured2The @ ZIF-67@ NiCo-LDH precursor SEM is similar to that of FIG. 3. Therefore, the SiO prepared by the preparation method of the embodiment of the invention2The @ ZIF-67@ NiCo-LDH precursor has stable structure and performance.
Further based on the Co, N-C @ NiCo provided for examples 1-32O4The test of the fuel cell catalyst shows that the grain diameter of Co and N-C as a nucleus body is 200-400 nm, and a cavity is arranged in the catalystThe diameter of the cavity is 100-200 nm, and the mesopores are uniformly distributed; NiCo2O4Is in the shape of nano-sheet and has a thickness of 50-100 nm. The electrochemical polarization curve (LSV, 5mV s) was recorded on the CHI 660E electrochemical workstation-1)
The Co, N-C @ NiCo provided in examples 1-3 above2O4The fuel cell catalysts were separately subjected to electrochemical polarization testing, wherein the Co, N-C @ NiCo provided in example 1 was used2O4The electrochemical polarization curve (LSV, 5mV s) was recorded on the CHI 660E electrochemical workstation-1) As shown in FIG. 4, it can be seen from FIG. 4 that Co, N-C @ NiCo provided in example 12O4The initial potential is 0.904V, the half-wave potential is 0.754V, and the limiting current density is 4.83mA/cm2. In addition, other examples, Co, N-C @ NiCo, were measured2O4The ORR polarization test is similar to that of FIG. 4, therefore, the fuel cell catalyst provided by the embodiment of the invention has stable catalytic performance and high catalytic activity.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. A fuel cell catalyst, characterized by: the fuel cell catalyst is of a core-shell structure, a core body of the core-shell structure is carbon particles, Co and N are doped in the carbon particles, and cavities are formed in the carbon particles; the shell layer of the core-shell structure coats the core body and grows on the surface of the core body, and the shell layer is made of NiCo2O4。
2. The fuel cell catalyst according to claim 1, characterized in that: the carbon particles are provided with porous structures, and the pore diameter of each porous structure is 5-30 nm; and/or
The shell layer is made of NiCo2O4Nanosheet composition, and the NiCo2O4Nanoplatelets grown on the core body surface; and/or
The Co doped in the carbon particles is doped in an amount of 4 to 6 at% in the carbon particles, and the N is doped in an amount of 2 to 4 at% in the carbon particles.
3. The fuel cell catalyst according to claim 1 or 2, characterized in that: the particle size of the carbon particles is 200-400 nm;
the thickness of the shell layer is 20-100 nm;
the diameter of the cavity is 100-200 nm.
4. A method of preparing a fuel cell catalyst, comprising the steps of:
dissolving a dispersing agent and soluble cobalt salt, and adding a nano-scale silicon source template for dispersion treatment to obtain a dispersion liquid containing the silicon source template; adding a 2-methylimidazole solution into the dispersion liquid, and carrying out mixing treatment and precipitation reaction to obtain first composite nanoparticles of a ZIF-67-coated silicon source template;
dispersing the first composite nano particles in a soluble nickel salt solution, mixing, and then carrying out solid-liquid separation to obtain second composite nano particles with a plurality of NiCo-LDH growing on the surfaces of the first composite nano particles;
calcining the second composite nanoparticles in an inert atmosphere to form NiCo-LDH into NiCo2O4The coating layer and the first composite nano particles are generated into carbon particles which are embedded with the nanoscale silicon source template and Co and N codoped, and the carbon particles are marked as third composite nano particles;
and (3) carrying out reaction treatment on the third composite nano particles in a strong alkali solution to remove the nano silicon source template.
5. The method of claim 4, wherein: in the dispersion liquid, the mass ratio of the silicon source template to the 2-methylimidazole is (2-4) to (1-2); and/or
The 2-methylimidazole solution is prepared by mixing a soluble cobalt salt and 2-methylimidazole according to a molar ratio of 1: (4-8) adding the mixture into the dispersion liquid; and/or
The molar ratio of the soluble cobalt salt contained in the soluble cobalt salt solvent to the soluble nickel salt contained in the soluble nickel salt solvent is 1: (0.5-2).
6. The production method according to claim 4 or 5, characterized in that: the silicon source template is carboxyl modified nano SiO2A template;
the dispersing agent comprises sodium dodecanesulphonate and commercial nano SiO2At least one of a special dispersant and a coupling agent KH 570;
the soluble cobalt salt comprises at least one of cobalt nitrate, cobalt sulfate and cobalt acetate;
the soluble nickel salt comprises at least one of nickel nitrate, nickel sulfate and nickel acetate.
7. The production method according to claim 4 or 5, characterized in that: the calcining treatment is carried out by heating to 500-800 ℃ at the speed of 1-5 ℃/min and keeping the temperature for 2-4 h; and/or
The strong alkali solution is 0.5-2 mol/mL NaOH solution, and the temperature of the third composite nano-particle in the strong alkali solution for reaction treatment is 60-80 ℃.
8. A fuel cell cathode, characterized by: the fuel cell cathode contains the fuel cell catalyst according to any one of claims 1 to 3 or the fuel cell catalyst produced by the production method according to any one of claims 4 to 7.
9. A fuel cell comprising a metal cathode, characterized in that: the metal cathode is the fuel cell cathode of claim 8.
10. The fuel cell according to claim 9, characterized in that: the fuel cell is a zinc-air cell.
CN202010447365.4A 2020-05-25 2020-05-25 Fuel cell catalyst, preparation method and application thereof Active CN113725449B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010447365.4A CN113725449B (en) 2020-05-25 2020-05-25 Fuel cell catalyst, preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010447365.4A CN113725449B (en) 2020-05-25 2020-05-25 Fuel cell catalyst, preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN113725449A true CN113725449A (en) 2021-11-30
CN113725449B CN113725449B (en) 2022-12-16

Family

ID=78671430

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010447365.4A Active CN113725449B (en) 2020-05-25 2020-05-25 Fuel cell catalyst, preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN113725449B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101602416B1 (en) * 2014-12-12 2016-03-11 한국에너지기술연구원 Cathode for Lithium-Air Battery, Method of Manufacturing the Same, and Lithium-Air Battery Comprising the Same
WO2016095669A1 (en) * 2014-12-17 2016-06-23 江苏合志锂硫电池技术有限公司 Preparation method for cobalt-nickel oxide electrode material
CN107359326A (en) * 2017-06-26 2017-11-17 江苏师范大学 A kind of Si@C lithium ion battery negative materials with core shell structure and preparation method thereof
CN109126850A (en) * 2018-08-08 2019-01-04 东华大学 A kind of hollow cobalt nickel coated nitrogen-doped carbon nanocomposite and preparation
CN109666949A (en) * 2019-01-03 2019-04-23 深圳清华大学研究院 The preparation method of the activated carbon electrodes of multi-element doping, the characterization of activated-carbon catalyst and hydrogen reduction electro-catalysis test method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101602416B1 (en) * 2014-12-12 2016-03-11 한국에너지기술연구원 Cathode for Lithium-Air Battery, Method of Manufacturing the Same, and Lithium-Air Battery Comprising the Same
WO2016095669A1 (en) * 2014-12-17 2016-06-23 江苏合志锂硫电池技术有限公司 Preparation method for cobalt-nickel oxide electrode material
CN107359326A (en) * 2017-06-26 2017-11-17 江苏师范大学 A kind of Si@C lithium ion battery negative materials with core shell structure and preparation method thereof
CN109126850A (en) * 2018-08-08 2019-01-04 东华大学 A kind of hollow cobalt nickel coated nitrogen-doped carbon nanocomposite and preparation
CN109666949A (en) * 2019-01-03 2019-04-23 深圳清华大学研究院 The preparation method of the activated carbon electrodes of multi-element doping, the characterization of activated-carbon catalyst and hydrogen reduction electro-catalysis test method

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
JIAN LI，等: ""ZIF-67 as Continuous Self-Sacrifice Template Derived NiCo2O4/Co,N-CNTs Nanocages as Efficient Bifunctional Electrocatalysts for Rechargeable Zn–Air Batteries"", 《ACS SUSTAINABLE CHEM. ENG.》 *
YUKE SONG，等: ""Hierarchical Hollow Co/N-C@NiCo2O4 Microsphere as an Efficient Bi-functional Electrocatalyst for Rechargeable Zn-Air Battery"", 《FRONTIERS IN MATERIALS》 *
苏丹阳等: "钴基材料的制备与应用研究进展", 《化工新型材料》 *

Also Published As

Publication number Publication date
CN113725449B (en) 2022-12-16

Similar Documents

Publication Publication Date Title
Wang et al. The application of CeO 2-based materials in electrocatalysis
CN110272035B (en) Method for preparing carbon nanocages by catalyzing organic ligands with metal ions, carbon nanocages prepared by method and application of carbon nanocages
CN107946560B (en) Carbon-limited domain metal or metal oxide composite nano-structure material and preparation method and application thereof
CN108767260B (en) Carbon-coated FeP hollow nano-electrode material and preparation method and application thereof
Fu et al. Spinel MnCo 2 O 4 nanoparticles cross-linked with two-dimensional porous carbon nanosheets as a high-efficiency oxygen reduction electrocatalyst
CN103840176B (en) Three-dimensional grapheme based combined electrode of a kind of area load Au nano particle and its preparation method and application
CN111244470B (en) Nano composite cathode and preparation and application thereof
CN108807943B (en) CeO with hollow structure2@ C core-shell nano composite material and preparation method and application thereof
WO2021104087A1 (en) Metal oxide nanoparticles, and preparation method therefor and application thereof
CN111744502B (en) Magnesium-doped cobalt disulfide composite carbon nanotube material, preparation method and application
CN112886029B (en) Preparation and application of bifunctional oxygen electrocatalyst with hollow carbon nanotube as carrier
CN110707301A (en) Vanadium trioxide/carbon composite material with nanosphere structure and preparation method and application thereof
WO2018176259A1 (en) Nano composite material and preparation method and application thereof
CN115259137B (en) Two-dimensional mesoporous carbon nano sheet and preparation method and application thereof
He et al. Facile formation of Fe-doped NiCoP hollow nanocages as bifunctional electrocatalysts for overall water splitting
CN113753963B (en) Tin cobalt disulfide nano-particles and preparation method and application thereof
CN114477300A (en) Sodium-ion battery positive electrode material and preparation method and application thereof
CN114420958A (en) Beaded cobalt-nitrogen co-doped carbon nanocage/carbon nanofiber composite catalyst and preparation method thereof
CN111450842B (en) Preparation method of micro-flower structure black lead-copper ore phase metal oxide electrocatalyst, electrocatalyst and application thereof
CN116936771A (en) Hollow spherical shell structure ferric sodium sulfate composite positive electrode material, preparation method and sodium ion battery
CN113725449B (en) Fuel cell catalyst, preparation method and application thereof
CN108448082B (en) Electrode material, petal-shaped porous structure iron-based composite oxide thereof and preparation method thereof
CN108400310A (en) A kind of anode material for lithium-ion batteries and preparation method thereof
CN115305496A (en) Preparation method and application of rare earth cerium-doped cobalt phosphide/iron phosphide heterogeneous material
CN114709428A (en) Defect tungsten oxide/ruthenium nanoparticle composite catalyst and preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant