CN-116417622-B - Method for rapidly preparing platinum-based bimetallic intermetallic compound and application thereof

Abstract

The invention discloses a method for rapidly preparing a platinum-based bimetallic intermetallic compound and application thereof. The method comprises the steps of firstly fully mixing a metal salt precursor, an inorganic auxiliary reagent and carbon black by ultrasonic, freeze-drying the mixed solution, and then performing thermal shock treatment by using joule to prepare the carbon-supported platinum-based bimetallic intermetallic compound catalyst. Compared with the traditional preparation strategy of the thermal annealing method, the method can rapidly prepare the platinum-based bimetallic intermetallic compound catalyst with high flux, the prepared intermetallic compound nano particles are uniformly loaded on the surface of carbon black, the size is uniform, the particle size is smaller, the agglomeration problem of the nano particles does not occur, and meanwhile, the method has the advantages of stable structure, multiple active sites and the like, shows excellent electrocatalytic activity for the cathode Oxygen Reduction Reaction (ORR) of the proton exchange membrane fuel cell, and has considerable energy application potential.

Inventors

• FU GENGTAO
• YAN WEI
• LI MENG
• LIN ZIJING
• LIU MANMAN
• TANG YAWEN

Assignees

• 南京师范大学

Dates

Publication Date

20260512

Application Date

20230307

Claims (5)

1. 1. A method for rapidly preparing a platinum-based bimetallic intermetallic compound, comprising the steps of: (1) Preparation of metal salt precursor-supported carbon black Uniformly mixing a platinum salt solution, a transition metal salt solution and an auxiliary reagent by ultrasonic, adding carbon black, and ultrasonically obtaining a metal salt precursor mixed solution, wherein the mole ratio of the platinum salt in the platinum salt solution to the transition metal salt is 1 (0.2-5), the mass ratio of the platinum salt in the platinum salt solution to the carbon black is 1 (1-18), and the auxiliary reagent is sodium citrate or potassium citrate, wherein the transition metal salt comprises manganese chloride, cobalt chloride, nickel chloride, manganese sulfate or manganese nitrate; (2) Preparation of platinum-based bimetallic intermetallic compound by Joule thermal shock And freeze-drying the metal salt precursor mixed solution to obtain precursor-loaded carbon black, and carrying out joule thermal shock on the precursor-loaded carbon black, and taking out, washing and drying after finishing to obtain a final product, wherein the joule thermal shock is carried out by clamping a sample to be thermally shocked by two pieces of carbon paper, placing the sample into a joule heating device, setting the impulse voltage to be 10-40V, the impulse current range to be 20-60A, the impulse current each time of the impulse current to be 2-5 seconds, the intermittent time between two adjacent times of the impulse current to be 2-10 seconds, the thermal shock circulation to be 4-16 times, and the thermal shock temperature range to be 800-1600 ℃ according to the impulse current.
2. 2. A method for rapidly preparing a platinum-based bimetallic intermetallic compound according to claim 1, wherein the platinum salt in step (1) comprises chloroplatinic acid, potassium chloroplatinic acid, sodium chloroplatinic acid or platinum chloride.
3. 3. A method for rapidly preparing a platinum-based bimetallic intermetallic compound according to claim 1, wherein the carbon black in step (1) comprises Vulcan XC72, ketjen Black EC300J or Ketjen Black EC600JD.
4. 4. The platinum-based bimetallic intermetallic compound prepared by the method of claim 1, wherein the platinum-based bimetallic intermetallic compound has uniform size of 4nm.
5. 5. The use of the method according to claim 1 as a catalyst for the cathodic oxygen reduction reaction of a proton exchange membrane fuel cell.

Description

Method for rapidly preparing platinum-based bimetallic intermetallic compound and application thereof Technical Field The invention relates to a method for rapidly preparing a platinum-based bimetallic intermetallic compound and application thereof, belonging to the technical field of intermetallic compound preparation processes. Background The fuel cell has been widely concerned with the advantages of high energy conversion efficiency, environmental protection of products, wide fuel range and the like, and has wide application prospect. Among them, proton Exchange Membrane Fuel Cells (PEMFCs) are often used in automobiles and portable electronic devices due to their compact structure, portability, high energy density, and the like. However, the slow kinetics of the cathodic oxygen reduction reaction and the high cost and low stability of the commonly used catalyst Pt severely hamper the wider commercial application of proton exchange membrane fuel cells. In order to solve the above problems, a series of non-noble metal-based catalysts have been developed with great efforts, but the application prospect of the non-noble metal-based catalysts is greatly restricted due to the difficulty in solving the problem of dissolution of the non-noble metal under acidic conditions, and the intrinsic activity and stability of the non-noble metal-based catalysts are far lower than those of the platinum-based catalysts. Therefore, the current commercial catalyst choice is still based on Pt. Therefore, the development of a platinum-based oxygen reduction reaction catalyst with a low noble metal loading, higher activity and durability is also the most important and urgent problem in the technical field of fuel cells. Alloying of platinum with transition metals is considered to be an effective strategy to reduce Pt usage and improve catalytic activity and stability. In particular, carbon-supported platinum-based bimetallic intermetallic compound nanoparticles are recognized as the most promising oxygen reduction catalyst with low platinum loading due to their excellent oxygen reduction activity and stability. Intermetallic compounds are a special class of alloy materials with defined stoichiometries and ordered crystal structures. In the platinum-based bimetallic intermetallic compound electrocatalyst, pt atoms and transition metal atoms are orderly arranged, so that the interaction between the two atoms is enhanced, and the catalytic activity and the overall structural stability of the catalyst are obviously improved. Conventional carbon-supported platinum-based bimetallic intermetallic compound catalysts are often synthesized by a post-impregnation tube furnace thermal annealing method. The metal salt precursor adheres to the carbon black surface by impregnation, followed by thermal annealing, and the high temperature promotes ordered arrangement of atoms to form intermetallic phases. However, the tube furnace thermal annealing generally takes several hours and the temperature rise and fall rate is slow, so that the problem of sintering agglomeration of metal particles is unavoidable during annealing, which results in the formation of intermetallic compounds of large particles, and the control of particle distribution, uniformity of particle diameter, and the like is difficult. Thus, it is very challenging and significant to explore a method for rapidly preparing platinum-based intermetallic compounds of sub-nanometer scale and uniform size. Disclosure of Invention In order to solve the problems in the prior art, the invention aims to provide a method for preparing a platinum-based bimetallic intermetallic compound rapidly and with high flux and application thereof, and the prepared intermetallic compound nano particles are uniformly loaded on the surface of carbon black, have uniform size of about 4nm, show excellent electrocatalytic activity on the cathodic oxygen reduction reaction of a proton exchange membrane fuel cell, and effectively solve the agglomeration problem of metal particles. In order to solve the problems in the prior art, the invention adopts the following technical scheme: A method for rapidly preparing a platinum-based bimetallic intermetallic compound comprising the steps of: (1) Preparation of metal salt precursor-supported carbon black Uniformly mixing a platinum salt solution, an excessive metal salt solution and an inorganic auxiliary reagent by ultrasonic waves, adding carbon black, and obtaining a metal salt precursor mixed solution by ultrasonic waves; (2) Preparation of platinum-based bimetallic intermetallic compound by Joule thermal shock And (3) freeze-drying the metal salt precursor mixed solution to obtain precursor-loaded carbon black, carrying out joule thermal shock on the precursor-loaded carbon black, and taking out, washing and drying after the completion of the joule thermal shock to obtain a final product. As an improvement, the platinum salt in the step (1) comprises chloroplatinic