CN111564640A - Method for synthesizing electrocatalyst with controllable nano structure - Google Patents

Method for synthesizing electrocatalyst with controllable nano structure Download PDF

Info

Publication number
CN111564640A
CN111564640A CN202010412223.4A CN202010412223A CN111564640A CN 111564640 A CN111564640 A CN 111564640A CN 202010412223 A CN202010412223 A CN 202010412223A CN 111564640 A CN111564640 A CN 111564640A
Authority
CN
China
Prior art keywords
carbon black
noble metal
conductive carbon
electrocatalyst
polyamide
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.)
Pending
Application number
CN202010412223.4A
Other languages
Chinese (zh)
Inventor
刘征
宋晨辉
王正罗
乔红艳
陈启章
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.)
Sinocat Environmental Technology Co Ltd
Original Assignee
Sinocat Environmental Technology Co Ltd
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 Sinocat Environmental Technology Co Ltd filed Critical Sinocat Environmental Technology Co Ltd
Priority to CN202010412223.4A priority Critical patent/CN111564640A/en
Publication of CN111564640A publication Critical patent/CN111564640A/en
Pending legal-status Critical Current

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
    • H01M4/88—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
    • H01M4/9041—Metals or alloys
    • 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
    • H01M4/9041—Metals or alloys
    • H01M4/905—Metals or alloys specially used in fuel cell operating at high temperature, e.g. SOFC
    • H01M4/9058—Metals or alloys specially used in fuel cell operating at high temperature, e.g. SOFC of noble metals or noble-metal based alloys
    • 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
    • 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

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Inert Electrodes (AREA)

Abstract

The invention discloses a method for synthesizing an electrocatalyst with a controllable nano structure. The method adopts polyamide-amine dendrimer as a template agent, and prepares the dendrimer-coated noble metal nano-particles with stable and controllable particle size and uniform particle size distribution through at least one complexing and reduction of noble metal ions; grinding conductive carbon black, and sequentially carrying out acidification and esterification or anhydride pretreatment to form surface functionalized carbon particles; and mixing the dendrimer coated noble metal nano particles with the pretreated conductive carbon black to prepare the conductive carbon black coated noble metal electrocatalyst. The invention controls and stabilizes the noble metal nanometer particle size range and forms uniform particle size distribution by the template agent and the metal ion repeated complexing and reducing technology; the functionalized conductive carbon black and the dendrimer are covalently crosslinked to form a conductive carbon black coated noble metal electrocatalyst, so that the conductivity of the electrocatalyst is improved; the invention adopts hydrosolvent as reaction auxiliary agent, has little pollution and is environment-friendly.

Description

Method for synthesizing electrocatalyst with controllable nano structure
Technical Field
The invention belongs to the technical field of catalyst design and preparation, particularly belongs to a preparation method of an electrocatalyst in a high-performance low-precious metal membrane electrode for a proton exchange membrane fuel cell, relates to the field of new energy materials and application in fuel cell automobiles, and particularly relates to a synthesis method of the electrocatalyst with a controllable nano structure.
Background
Proton Exchange Membrane Fuel Cells (PEMFC) can be operated at room temperature to 100 ℃ due to their low operating temperature, are safe and pollution-free, and do not use corrosive electrolyte or high-temperature molten salt characteristics; compared with an internal combustion engine, the energy density and the power density are high, the application prospect of the new generation energy technology is wide, and the market potential is huge. However, the key component of the fuel cell, the Membrane Electrode Assembly (MEA), the key component of the electrocatalyst, is the biggest obstacle to the commercial application of the pem fuel cell due to its low electrochemical activity and noble metal utilization rate, and high cost. In recent decades, the academia and industry have been working on exploring and developing new electrocatalysts to meet the requirements of commercial catalysts for high efficiency, durability and low cost.
The traditional preparation method of the electrocatalyst, such as wet impregnation, coprecipitation method, sol-gel method, etc., is widely applied to the production of industrial catalysts due to simple preparation process and low cost, but the traditional method is often difficult to control the particle size and uniform distribution of the active components of the catalyst, thereby causing that the dispersion degree can not meet the requirement, the utilization rate of the precious metals of the effective active components is low, and the cost is greatly increased.
The polyamide-amine dendrimer (PAMAM dendrimer) has a nano-scale cavity inside and is a very effective template agent for synthesizing and stabilizing nano metal particles. In recent years, the polyamide-amine dendrimer coated metal electrocatalyst has received extensive attention from basic research due to its controllable particle size and uniformity, but its application in fuel cell industrialization is limited due to low electrochemical activity. The low activity mainly comes from two aspects: firstly, the surface electrical property is poor because the active noble metal is formed inside the polyamide-amine dendrimer; the second is that the nanoparticles produced by this method are small, on average less than 2nm, and are not the optimal particle size for cathodic Oxygen Reduction Reaction (ORR) activity, which is typically 3nm, resulting in poor electrochemical activity.
The current fuel cell catalyst has the following defects: 1) the catalytic activity of the cathode oxygen reduction reaction is poor; 2) precious metal (PGM) nanoparticles are not uniformly distributed, and the particle size is difficult to control and is stable in a high activity range; 3) for the catalyst with noble metal nano particles (PGM-DENs) wrapped by polyamide-amine dendrimer, the conductivity is poor, so that the electrochemical activity is poor; 4) the noble metal active component has low dispersity and low utilization rate, so that the catalyst has high cost; 5) the preparation process is complex and is not environment-friendly.
The following are the english abbreviations referred to herein:
PAMAM, polyamidoamine;
PAMAM dendrimer, polyamidoamine dendrimer;
PEMFCs, proton exchange membrane fuel cells;
MEA, membrane electrode assembly;
PGM, noble metals;
ORR, cathodic oxygen reduction reaction;
DENs, dendrimer coated (or stabilized) nanoparticles;
PGM-DENs, polyamide-amine dendrimer wraps the noble metal nanoparticles;
pgm (c) -DENs, conductive carbon black coated noble metal electrocatalyst;
MES, 2- (N-morpholine) ethanesulfonic acid;
EDC, coupling agent for peptide synthesis;
NHS, N-hydroxysuccinimide;
EFC, ethyl chloroformate;
NMM, N-methylmorpholine;
DMF, dimethylformamide.
Disclosure of Invention
The invention discloses an electrocatalyst synthesis method with controllable nano-structure according to the deficiency of the prior art. The invention aims to provide a simple and environment-friendly method for synthesizing a high-efficiency fuel cell catalyst with controllable nano particle size and uniformity by utilizing a special tree-shaped structure of a polyamide-amine dendrimer, and the conductivity of the catalyst is improved by covalently crosslinking the surface of the polyamide-amine dendrimer by conductive carbon particles.
The invention is realized by the following technical scheme:
the method for synthesizing the electrocatalyst with controllable nano structure is characterized in that:
preparing polyamide-amine dendrimer coated noble metal nano particles with stable and controllable particle size and uniform particle size distribution by adopting polyamide-amine dendrimer as a template agent and complexing and reducing noble metal ions at least once;
grinding conductive carbon black to obtain a particle size smaller than 1 micron, and sequentially carrying out acidification and esterification pretreatment or acidification and anhydrization pretreatment to form surface functionalized carbon particles;
and mixing the polyamide-amine dendrimer coated noble metal nano particles with the pretreated conductive carbon black to prepare the conductive carbon black coated noble metal electrocatalyst.
The complexing and reducing preparation of the polyamide-amine dendrimer coated noble metal nanoparticles comprises the following steps: dispersing polyamide-amine dendrimer into deionized water, adjusting the pH to 2-7, adding a solution prepared from noble metal-containing acid or noble metal salt according to the molar ratio of noble metal to polyamide-amine dendrimer being greater than 30 under stirring to completely complex noble metal ions by the polyamide-amine dendrimer to form a solution of polyamide-amine dendrimer coated with noble metal ions; then dropwise adding excessive NaBH at the temperature of between 0 and room temperature under the condition of vigorous stirring4Continuously stirring the solution to ensure that metal ions are completely reduced, separating, washing and drying the solution to obtain polyamide-amine dendrimer coated noble metal nanoparticles prepared by primary complexation and reduction; wherein, NaBH4The solution is 0.3-0.5M NaBH4Mixed with 0.1-0.3M NaOH.
The conductive carbon black acidification pretreatment is to grind the conductive carbon black into particles smaller than 1 micron, and then carry out acidification in a concentrated acid solution to form surface carboxylic acid groups.
The conductive carbon black esterification pretreatment is that the conductive carbon black after acidification pretreatment is ultrasonically dispersed in 2- (N-morpholine) ethanesulfonic acid buffer aqueous solution, a coupling agent synthesized by peptide is dripped under the condition of violent stirring, and N-hydroxysuccinimide is added to form the surface functionalized conductive carbon black.
The conducting carbon black anhydrization pretreatment is to transfer the conducting carbon black subjected to acidification pretreatment to a dimethylformamide solution containing ethyl chloroformate and N-methylmorpholine to obtain the anhydride functionalized conducting carbon black.
The noble metal nano particles coated by the polyamide-amine dendrimer and the pretreated conductive carbon black are mixed according to the mass ratio of the prepared noble metal nano particles coated by the polyamide-amine dendrimer to the conductive carbon black of 0.01-0.1 percent, and the mixture is stirred and mixed at room temperature to prepare the conductive carbon black coated noble metal electrocatalyst.
The invention controls the nanometer particle size of the catalyst by the metal ion repeated complexing and reducing technology, and meets the size and structure required by the cathode Oxygen Reduction Reaction (ORR); the functionalized conductive carbon black is covalently crosslinked with polyamide-amine dendrimer (PAMAM dendrimer) to form a conductive carbon black coated noble metal electrocatalyst (PGM (C) -DENs), so that the conductivity of the electrocatalyst is improved, and the electrochemical activity of the catalyst is improved; the invention provides a proper process technical route for future high-efficiency macro production of the fuel cell catalyst; the invention adopts hydrosolvent as reaction auxiliary agent, has little pollution and is environment-friendly.
The invention provides a new synthesis method of a noble metal nano electrocatalyst, which is used for improving the electrochemical activity of the noble metal electrocatalyst; the method controls and stabilizes the noble metal nano particle size in the optimal range and forms uniform particle size distribution by taking polyamide-amine dendrimer (PAMAM dendrimer) as a template agent and repeatedly complexing and reducing metal ions; the conductive carbon black is subjected to acidification pretreatment and esterification or anhydrization treatment to form carboxyl functional groups on the surface, and further forms covalent crosslinking with the surfaces of the polyamide-amine dendrimer coated noble metal nano particles (PGM-DENs) so as to improve the conductivity of the prepared conductive carbon black coated noble metal electro-catalyst (PGM (C) -DENs).
Drawings
FIG. 1 is a schematic diagram of the synthetic route of the polyamide-amine dendrimer-coated noble metal nanoparticles (PGM-DENs) according to the present invention.
FIG. 2 is a schematic diagram of the synthesis route of the conductive carbon black coated noble metal electrocatalysts (PGM (C) -DENs) of the present invention.
FIG. 3 is a TEM image of conductive carbon black-coated platinum electrocatalyst (Pt (C) -DENs1) prepared in example 1 of the present invention.
FIG. 4 is a normal distribution diagram of the average particle size of the corresponding nanoparticles of the conductive carbon black-coated platinum electrocatalyst (Pt (C) -DENs1) prepared in example 1 according to the present invention. In the figure, the average particle size of the nanoparticles is about 2.1nm with the highest distribution, the main range being 1-2.6 nm.
FIG. 5 is a TEM image of conductive carbon black-coated platinum electrocatalyst (Pt (C) -DENs2) prepared by re-complexing and reduction according to example 1 of the present invention.
FIG. 6 is a normal distribution diagram of the average particle size of the corresponding nanoparticles of the conductive carbon black-coated platinum electrocatalyst (Pt (C) -DENs2) prepared by re-complexing and reduction according to example 1 of the present invention. In the figure, the average particle size of the nanoparticles is about 3.2nm with the highest distribution, the main range being 2-3.5 nm.
FIG. 7 is a transmission electron micrograph of a Pt/C electrocatalyst prepared according to the comparative example.
FIG. 8 is a normal distribution diagram of the average particle size of the metal particles corresponding to the Pt/C electrocatalyst prepared in the comparative example. In the figure, the average particle size of the nanoparticles is about 3.5nm with the highest distribution, ranging from 1.5 to 6.5 nm.
FIG. 9 is a linear voltage sweep (LSV) plot of the electrochemical performance of the conductive carbon black coated platinum electrocatalysts (Pt (C) -DENs) prepared in accordance with the present invention versus Pt/C catalysts.
FIG. 10 is a comparison of specific mass activities of Pt (C) -DENs and Pt/C redox catalysts (ORR) prepared according to the present invention, where the ordinate is the specific mass activity measured by RDE (Rolling-disk-electrode).
Detailed Description
The present invention is further described below in conjunction with the following detailed description, which is intended to further illustrate the principles of the invention and is not intended to limit the invention in any way, but is equivalent or analogous to the present invention without departing from its scope.
Example 1
(1) Pt nanoparticles (Pt-DENs) synthesis, combined with figure 1:
dispersing a certain amount of polyamide-amine dendrimer polymer in deionized water to prepare an aqueous solution with a concentration of 0.1-2.0 wt%, wherein the polyamide-amine dendrimer (PAMAM Dendrimers) is selected from second to tenth generation polyamide-amine Dendrimers (PAMAM Dendrimers, OH-or NH)2-terminated G2-G10); adjusting pH of the solution to 2-7 with dilute hydrochloric acid, and adding 0.2-0.5M chloroplatinic acid salt or chloroplatinic acid (K)2PtCl4Or H2PtCl4) Adding the aqueous solution into the polyamide-amine dendrimer aqueous solution according to the molar ratio of the noble metal to the polyamide-amine dendrimer greater than 30, stirring the formed mixed solution at room temperature for at least 48 hours to fully complex Pt ions in the polyamide-amine dendrimer, and then adding excessive 0.1-0.3M NaBH4Adding the aqueous solution into the mixed solution at the temperature of 5-25 ℃ under stirring, carrying out reduction reaction until the complexed Pt ions are completely reduced to form polyamide-amine dendrimer coated stabilized platinum nanoparticles (Pt-DENs), and finally filtering, washing and drying at 80 ℃.
As shown in fig. 1, the polyamide-amine dendrimer-coated stabilized platinum nanoparticles (Pt-DENs) prepared in the above steps can be further dispersed in deionized water by ultrasound, and the preparation processes such as complexation and reduction are repeated to further adjust the size of the metal nanoparticles and the number of particles formed in the polyamide-amine dendrimer. Among them, the use of the tenth generation (G10) polyamidoamine dendrimer enables a plurality of metal nanoparticles to be stabilized inside thereof. The polyamidoamine dendrimers employed in the present invention are commercially available.
The following steps are combined with fig. 2.
(2) Carbon black acidification treatment
Firstly, grinding conductive carbon black to particles smaller than 1 micron, weighing 0.5g of conductive carbon black by mass, adding the conductive carbon black into a concentrated nitric acid solution, stirring the mixture for 10 hours at room temperature, washing the mixture by using deionized water, filtering the mixture, drying the filtrate, and transferring the dried filtrate into 200ml of deionized water for ultrasonic dispersion for further use.
Conductive carbon blacks such as: vulcan XC-72R, XC-72 (CARBOT USA); XC-72R (CARBOT, USA); black Pearls 2000 (CARBOTS USA); acetylene black; ketjen Black series conductive carbon Black (Japan lion king company).
(3) Functionalization of conductive carbon black
Adding 0.5M 2- (N-morpholine) ethanesulfonic acid (MES) buffer water to the acidified carbon black solution of step (2), then adding 100ml of 0.2M peptide synthesis coupling agent (EDC) solution dropwise to the acidified carbon black solution containing the buffer solution under vigorous stirring, stirring for another 30 minutes, then adding 100ml of 0.2M N-hydroxysuccinimide (NHS) solution, and continuing stirring for 2 hours to complete the esterification of N-hydroxysuccinimide. Finally, separation, washing by deionized water and drying at 80 ℃.
(4) Preparation of conductive carbon black coated Pt-DENs catalyst
Taking the esterified functionalized carbon particles obtained in the step (3), ultrasonically dispersing the esterified functionalized carbon particles in 20ml of 0.5M 2- (N-morpholine) ethanesulfonic acid buffer aqueous solution, and mixing the Pt-DENs prepared in the step (1) with the conductive carbon black according to the mass ratio of the Pt-DENs to the conductive carbon black: adding Pt-DENs into the buffer solution with the concentration of 0.01-0.1%, stirring for 1-2 hours to ensure that amidation between the functionalized carbon and the Pt-DENs is complete, separating and filtering, washing with deionized water until the pH value is neutral, and drying at 50 ℃ to prepare the conductive carbon black coated platinum electrocatalyst (Pt (C) -DENs).
Example 2
(1) Au-DENs nanoparticle synthesis
Dispersing a certain amount of polyamide-amine dendrimer polymer in deionized water to prepare an aqueous solution with the concentration of 0.1-2.0 wt%, wherein the polyamide-amine dendrimer (PAMAM Dendrimers) is selected from second-generation to tenth-generation polyamide-amine Dendrimers (PAMAM Dendrimers, OH-or NH)2-terminated G2-G10); adjusting the pH of the solution to 2-7 with dilute hydrochloric acid, and adding 0.3-0.5M chloroauric acid salt or chloroauric acid (HAuCl)4Or KAuCl4) Aqueous solution of noble metal in molar ratio to polyamidoamine dendrimer of more than 30Proportionally adding into polyamide-amine dendrimer aqueous solution, stirring the formed mixed solution at room temperature for 24 hours to fully complex Au ions in the polyamide-amine dendrimer, and then adding excessive 0.1-0.3M NaBH4And dropwise adding an alkaline aqueous solution into the mixed solution at the temperature of 0-10 ℃ under stirring, carrying out reduction reaction until the complexed Au ions are completely reduced to form polyamide-amine dendrimer coated stabilized gold nanoparticles (Au-DENs), and finally filtering, washing and drying at 80 ℃.
As shown in fig. 1, the polyamide-amine dendrimer-coated stabilized gold nanoparticles (Au-DENs) prepared in the above steps can be further dispersed in deionized water by ultrasound, and the preparation processes such as complexation and reduction are repeated to further adjust the size of the metal nanoparticles and the number of particles formed in the polyamide-amine dendrimer.
(2) Carbon black acidification treatment
Same as example 1
(3) Functionalization of conductive carbon black
Same as example 1
(4) Preparation of conductive carbon black coated Au-DENs catalyst
Taking the esterified functionalized carbon particles obtained in the step (3), ultrasonically dispersing the esterified functionalized carbon particles in 20ml of 0.5M 2- (N-morpholine) ethanesulfonic acid (MHS) buffer aqueous solution, and preparing the ratio of the mass ratio (C/Au-DENs) of the Au-DENs prepared in the step (1) to the mass ratio of the conductive carbon black: adding 0.01-0.1% of the gold-coated carbon black into the Au-DENs prepared in the step (1), stirring for 1-2 hours to ensure that amidation between the functionalized carbon and the Au-DENs is complete, separating and filtering, washing with deionized water until the pH value is neutral, and drying at 50 ℃ to prepare the conductive carbon black coated gold electrocatalyst (Au (C) -DENs).
Example 3
(1) Pt-DENs nanoparticle synthesis
Same as example 1
(2) Carbon black acidification treatment
Same as example 1
(3) Functionalization of conductive carbon black
Transferring the acidified carbon black solution obtained in the step (2) into a Dimethylformamide (DMF) solution containing ethyl chloroformate (EFC) and N-methylmorpholine (NMM), and stirring the mixed solution in an ice bath at 0-5 ℃ for 2 hours to form Active anhydride (Active anhydride) on the carbon surface. Then separating, fully washing by deionized water, and drying at 80 ℃ to obtain the anhydride functionalized conductive carbon black.
(4) Preparation of conductive carbon black coated Pt-DENs catalyst
Ultrasonically dispersing the conductive carbon black particles subjected to surface anhydrization in the step (3) in 20ml of deionized water, and mixing the Pt-DENs prepared in the step (1) with the conductive carbon black according to the mass ratio (C/Pt-DENs): adding 0.01-0.1% of the Pt-DENs prepared in the step (1), stirring for 1-2 hours to ensure that amidation between the functionalized carbon and the Pt-DENs is complete, separating and filtering, washing with deionized water until the pH value is neutral, and drying at 50 ℃ to prepare the conductive carbon black coated platinum electrocatalyst (Pt (C) -DENs).
Comparative example 1
Commercial Pt/C (Alfa, 20 wt% Pt) catalysts, which do not contain polyamide dendrimers, were prepared by a conventional impregnation method and used for electrochemical activity comparison with the catalysts synthesized in accordance with the present invention.
The invention carries out comparative detection on the catalysts prepared in the examples and the comparative examples, and the detection preparation method comprises the following steps:
preparing a working electrode:
the surface area is 0.071cm2The glassy carbon electrode was used to prepare a working electrode, 1-3 mg of the catalyst prepared in each example, including a commercial Pt/C (Alfa, 20 wt% Pt) catalyst, was weighed, 970 microliters of isopropyl alcohol and 30 microliters of Nafion membrane solution were added thereto in sequence, the mass fraction was 5 wt%, after being uniformly dispersed by ultrasonic oscillation for 30-60 minutes, 5 microliters was absorbed by a micropipette and uniformly coated on a glassy carbon rotating disk electrode, and spin-dried in air for 10 minutes, to obtain a catalyst working electrode.
Electrochemical activity test:
the electrochemical activity of the catalyst can be measured by Cyclic Voltammetry (CV) and linear scanning technology, an Autolab PGSTAT30(Eco Chemie) electrochemical workstation and a Pine RDE are used, a three-electrode system is adopted in the test, a glassy carbon electrode loaded with the carbon-coated electrocatalyst and the commercial Pt/C catalyst prepared in the embodiment of the invention is used as a working electrode, an Ag/AgCl electrode is used as a reference electrode, a Pt wire is used as an auxiliary electrode, 0.1mol/L perchloric acid aqueous solution saturated by oxygen is used as an electrolyte solution, a linear scanning polarization curve is recorded on the Autolab PGSTAT30 of the electrochemical workstation, the rotating speed of a rotating electrode is 1600rpm, the scanning range is 0.1-1.0V (relative to a standard hydrogen electrode), and the scanning speed is 20 mV/s.
The detection results are shown in the figure. Compared with the current commercial fuel cell platinum-carbon (Pt/C) catalyst, as shown in transmission electron microscope photographs (TEM Images) of the catalyst obtained by different preparation methods shown in figures 3 to 8, the conductive carbon black synthesized by the process route of the invention coats the platinum electrocatalyst (Pt (C) -DENs), the particle size of the conductive carbon black is easy to control and the particle size distribution is uniform, so that the utilization rate of precious metals of the catalyst is improved, and the cost is reduced. The invention adopts the PGM-DENS preparation process technology coated by conductive carbon, overcomes the defect of poor conductivity of pure PGM-DENs, promotes the transmission of electrons between the electrode and the active noble metal particles, thereby obviously improving the electrochemical activity of the cathode Oxygen Reduction Reaction (ORR), and the activity test result of the oxidation reduction reaction confirms the conclusion in figures 9 and 10.
As shown in fig. 10, comparing the electrocatalysts pt (c) -DENs1 and pt (c) -DENs2 implemented in fig. 10, it can be seen that the effect of the size of the nano-metal particles on the electrocatalytic activity is significant. The invention is one of the important innovation points of the invention that the structure and the particle size of the nano catalyst are improved by the repeated complexation and reduction technology of the noble metal ions, so as to improve the performance of the electrocatalyst.
The invention provides a high-efficiency nano electro-catalyst synthesis technology by taking polyamide-amine dendrimer as a template agent and a stabilizer. Compared with the prior art and products, the preparation process adopted by the invention is a simple and environment-friendly technology, thereby providing a proper and effective catalyst material for further developing a high-efficiency and low-platinum catalytic membrane electrode (CCM) and a Membrane Electrode Assembly (MEA).

Claims (6)

1. A method for synthesizing an electrocatalyst with controllable nano-structure is characterized in that:
preparing polyamide-amine dendrimer coated noble metal nano particles with stable and controllable particle size and uniform particle size distribution by adopting polyamide-amine dendrimer as a template agent and complexing and reducing noble metal ions at least once;
grinding conductive carbon black to obtain a particle size smaller than 1 micron, and sequentially carrying out acidification and esterification pretreatment or acidification and anhydrization pretreatment to form surface functionalized carbon particles;
and mixing the polyamide-amine dendrimer coated noble metal nano particles with the pretreated conductive carbon black to prepare the conductive carbon black coated noble metal electrocatalyst.
2. The method of claim 1, wherein the complexing and reductive preparation of the polyamidoamine dendrimer coated noble metal nanoparticles comprises: dispersing polyamide-amine dendrimer into deionized water, adjusting the pH to 2-7, adding a solution prepared from noble metal-containing acid or noble metal salt according to the molar ratio of noble metal to polyamide-amine dendrimer being greater than 30 under stirring to completely complex noble metal ions by the polyamide-amine dendrimer to form a solution of polyamide-amine dendrimer coated with noble metal ions; then dropwise adding excessive NaBH at the temperature of between 0 and room temperature under the condition of vigorous stirring4Continuously stirring the solution to ensure that metal ions are completely reduced, separating, washing and drying the solution to obtain polyamide-amine dendrimer coated noble metal nanoparticles prepared by primary complexation and reduction; wherein, NaBH4The solution is 0.3-0.5M NaBH4Mixed with 0.1-0.3M NaOH.
3. A method of synthesising an electrocatalyst with controllable nanostructures according to claim 2 characterised in that: the conductive carbon black acidification pretreatment is to grind the conductive carbon black into particles smaller than 1 micron, and then carry out acidification in a concentrated acid solution to form surface carboxylic acid groups.
4. A method of synthesising an electrocatalyst with controllable nanostructures according to claim 3 characterised in that: the conductive carbon black esterification pretreatment is that the conductive carbon black after acidification pretreatment is ultrasonically dispersed in 2- (N-morpholine) ethanesulfonic acid buffer aqueous solution, a coupling agent synthesized by peptide is dripped under the condition of violent stirring, and N-hydroxysuccinimide is added to form the surface functionalized conductive carbon black.
5. A method of synthesising an electrocatalyst with controllable nanostructures according to claim 3 characterised in that: the conducting carbon black anhydrization pretreatment is to transfer the conducting carbon black subjected to acidification pretreatment to a dimethylformamide solution containing ethyl chloroformate and N-methylmorpholine to obtain the anhydride functionalized conducting carbon black.
6. A method of synthesising an electrocatalyst with controllable nanostructures according to claim 4 or 5 characterised in that: the noble metal nano particles coated by the polyamide-amine dendrimer and the pretreated conductive carbon black are mixed according to the mass ratio of the prepared noble metal nano particles coated by the polyamide-amine dendrimer to the conductive carbon black of 0.01-0.1 percent, and the mixture is stirred and mixed at room temperature to prepare the conductive carbon black coated noble metal electrocatalyst.
CN202010412223.4A 2020-05-15 2020-05-15 Method for synthesizing electrocatalyst with controllable nano structure Pending CN111564640A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010412223.4A CN111564640A (en) 2020-05-15 2020-05-15 Method for synthesizing electrocatalyst with controllable nano structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010412223.4A CN111564640A (en) 2020-05-15 2020-05-15 Method for synthesizing electrocatalyst with controllable nano structure

Publications (1)

Publication Number Publication Date
CN111564640A true CN111564640A (en) 2020-08-21

Family

ID=72072182

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010412223.4A Pending CN111564640A (en) 2020-05-15 2020-05-15 Method for synthesizing electrocatalyst with controllable nano structure

Country Status (1)

Country Link
CN (1) CN111564640A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112701308A (en) * 2020-12-29 2021-04-23 华南理工大学 Preparation method of fuel cell catalyst with high durability

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102218544A (en) * 2011-05-27 2011-10-19 中国科学院理化技术研究所 Preparation method and application of metal nanoparticles
CN102671710A (en) * 2011-03-07 2012-09-19 河南科技大学 Noble metal nanocatalyst loaded on dendritic macromolecule functionalized graphene and preparation method thereof
CN104209539A (en) * 2014-09-28 2014-12-17 中南大学 Method for preparing gold nanoparticles based on polyamidoamine amine supermolecular hyperbranched polymer
JP2017087151A (en) * 2015-11-11 2017-05-25 国立大学法人東京工業大学 Metal nanocluster catalyst

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102671710A (en) * 2011-03-07 2012-09-19 河南科技大学 Noble metal nanocatalyst loaded on dendritic macromolecule functionalized graphene and preparation method thereof
CN102218544A (en) * 2011-05-27 2011-10-19 中国科学院理化技术研究所 Preparation method and application of metal nanoparticles
CN104209539A (en) * 2014-09-28 2014-12-17 中南大学 Method for preparing gold nanoparticles based on polyamidoamine amine supermolecular hyperbranched polymer
JP2017087151A (en) * 2015-11-11 2017-05-25 国立大学法人東京工業大学 Metal nanocluster catalyst

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
A. ARUNCHANDER等: "Dendrimer confined Pt nanoparticles: electrocatalytic activity towards the oxygen reduction reaction and its application in polymer electrolyte membrane fuel cells", 《RSC ADVANCES》 *
YINGQIANG HUANG等: "Facile synthesis of poly(amidoamine)-modified carbon nanospheres supported Pt nanoparticles for direct methanol fuel cells", 《JOURNAL OF POWER SOURCES》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112701308A (en) * 2020-12-29 2021-04-23 华南理工大学 Preparation method of fuel cell catalyst with high durability

Similar Documents

Publication Publication Date Title
US8409659B2 (en) Nanowire supported catalysts for fuel cell electrodes
US9331341B2 (en) Durable platinum/multi-walled carbon nanotube catalysts
Zhu et al. Facile preparation of carbon-supported Pd nanoparticles for electrocatalytic oxidation of formic acid
CN112823880B (en) Catalyst with high metal loading capacity and preparation and application thereof
KR101197172B1 (en) Method for one-pot synthesizing of catalyst for fuel cell having nano structure shape
KR101679809B1 (en) Preparation method of N-doped carbon-supported Pt catalyst and N-doped carbon-supported Pt catalyst using the same
KR101229400B1 (en) Platinum/ruthenium catalyst for direct methanol fuel cells
US20070161501A1 (en) Method for making carbon nanotube-supported platinum alloy electrocatalysts
CN106571474B (en) Preparation method of platinum-nickel alloy nanocluster and fuel cell adopting platinum-nickel alloy nanocluster
CN111710879A (en) Nitrogen-doped carbon-supported platinum-based electrocatalyst and synthesis method thereof
Khalifeh-Soltani et al. Pt–Ru nanoparticles anchored on poly (brilliant cresyl blue) as a new polymeric support: Application as an efficient electrocatalyst in methanol oxidation reaction
Xie et al. Effect of mesoporous carbon on oxygen reduction reaction activity as cathode catalyst support for proton exchange membrane fuel cell
CN114094130B (en) Preparation method of fuel cell platinum alloy catalyst
CN111564641B (en) Preparation method of catalyst layer in membrane electrode
CN110350204B (en) Fuel cell catalyst with gold nanocluster as core and platinum as shell layer and preparation method and application thereof
CN111564640A (en) Method for synthesizing electrocatalyst with controllable nano structure
CN111530499B (en) Synthesis method of core-shell alloy electrocatalyst with controllable structure
CN112397732A (en) ORR catalyst material and preparation method and application thereof
CN111816888A (en) Alloy nano catalyst, preparation method thereof and fuel cell
CN109301269B (en) PtAgCo/C nanoflower structure catalytic material, preparation method thereof and application of catalytic material as fuel cell catalyst
CN111883791A (en) Preparation method of trimetal platinum palladium chromium direct ethanol fuel cell catalyst
CN108892773B (en) Porphyrin polymer nano material, preparation method and application thereof
KR100665689B1 (en) Catalyst for low temperature fuel cell using supports modified in order to have ion conductivity, method to prepare the same, electrode for low temperature fuel cell using the catalyst, method to prepare the same, membrane-electrode assembly for low temperature fuel cell using the catalyst, method to prepare the same, low temperature fuel cell using the catalyst and method to prepare the same
CN114335577B (en) Modified catalyst, membrane electrode, preparation method of modified catalyst and membrane electrode, and fuel cell
KR20120039992A (en) Pt-au nanocomposite catalyst for fuel cell and its preparing method

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
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20200821