Platinum-nickel catalyst, direct formic acid fuel cell as well as preparation method and application of platinum-nickel catalyst
By preparing high-performance platinum-nickel catalysts, the problems of insufficient catalyst stability and durability in DFAFCs have been solved, achieving improved catalytic performance and reduced costs, thus promoting the commercialization of DFAFCs.
Patent Information
- Application Number
- CN202511650413.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-12
- Publication Date
- 2026-02-17
AI Technical Summary
The platinum-nickel catalysts in existing direct formic acid fuel cells (DFAFCs) have poor stability and durability, and low utilization of precious metals, which limits their commercial development.
A platinum-nickel catalyst was prepared by ultrasonic treatment of a mixed solution of polyvinylpyrrolidone, glycine, chloroplatinic acid and nickel chloride in water, followed by reduction with sodium borohydride, centrifugation and washing purification. The catalyst was then mixed with Nafion solution to form a catalyst slurry, which was sprayed onto the electrode surface and hot-pressed to prepare a membrane electrode assembly. A direct formic acid fuel cell was then assembled.
The platinum-nickel catalyst exhibits a threefold increase in catalytic performance and a reduction in cost, resulting in a significant improvement in the performance of direct formic acid fuel cells and demonstrating potential for large-scale commercial production.
Smart Images
Figure CN121546080A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fuel cell technology, and more specifically to a platinum-nickel catalyst, a direct formic acid fuel cell, its preparation method, and its application. Background Technology
[0002] Direct formic acid fuel cells (DFAFCs), as proton exchange membrane fuel cells that use liquid formic acid as fuel, have advantages such as being non-toxic, safe, having high energy conversion efficiency, and being easy to operate, and have broad application prospects in automobiles and portable electronic devices.
[0003] However, the stability and durability of platinum-nickel catalysts for DFAFCs are still poor, and the utilization rate and amount of precious metals are low, which seriously limits the commercial development of DFAFCs.
[0004] Therefore, how to develop a high-performance platinum-nickel catalyst that can be used in DFAFCs is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] In view of this, the purpose of the present invention is to provide a platinum-nickel catalyst, a direct formic acid fuel cell, and a method for preparing and applying the same, so as to overcome the shortcomings of the prior art.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A method for preparing a platinum-nickel catalyst specifically includes the following steps:
[0008] (1) Mix polyvinylpyrrolidone, glycine, chloroplatinic acid and nickel chloride in water and stir, then sonicate to obtain a uniform yellow solution;
[0009] (2) Sodium borohydride was added as a reducing agent to carry out the reaction. After centrifugation and washing purification, the platinum-nickel catalyst was obtained.
[0010] Furthermore, in step (1) above, the molecular weight (mW) of polyvinylpyrrolidone (PVP) is 30,000; the ratio of polyvinylpyrrolidone, glycine, chloroplatinic acid, nickel chloride and water is 1000mg:(190-440)mg:158mg:12.88mg:25mL, preferably 1000mg:290mg:158mg:12.88mg:25mL; the mixing time is 5min.
[0011] Furthermore, in step (2) above, the amount of sodium borohydride added is 10-15 mg, preferably 15 mg; the centrifugation speed is 10000 r / min and the time is 8 min; the washing and purification reagent is acetone.
[0012] The present invention also claims protection for a platinum-nickel catalyst prepared by the above-described preparation method.
[0013] The present invention also claims protection for the use of a platinum-nickel catalyst prepared by the above-described method in the preparation of a direct formic acid fuel cell.
[0014] A method for preparing a direct formic acid fuel cell specifically includes the following steps:
[0015] (1) Add Nafion solution, isopropanol and water as dispersants to the platinum-nickel catalyst prepared by the above preparation method to form a mixture, and disperse it by ultrasonication to obtain a uniform catalyst slurry.
[0016] (2) A catalyst layer slurry is sprayed onto the microporous layer surface of the anode and cathode of the direct formic acid fuel cell, respectively. First, the carbon paper coated with the catalyst layer slurry is dried. Then, a layer of Nafion solution is brushed onto the treated anode and cathode electrode surfaces. The sides coated with the catalyst layer slurry are placed face to face on both sides of the Nafion membrane. The three are clamped with metal plates and hot-pressed to obtain the membrane electrode assembly (MEA).
[0017] (3) Use a gasket to sandwich the membrane electrode in the middle, place it between two graphite plates, and then assemble the upper end plate on both sides and fix it with nuts to obtain a direct formic acid fuel cell.
[0018] Furthermore, in step (1) above, the concentration of the Nafion solution is 5 wt%; the mass ratio of the platinum-nickel catalyst to the Nafion solution is 7:3; the ultrasonic dispersion time is 1.0 h; and the solid content of the catalyst slurry is 1%.
[0019] Furthermore, in step (2) above, the spraying equipment is a spray gun with a working pressure of 1.5 MPa; the drying equipment is a drying oven with a temperature of 60℃ and a time of 2.0 h; the hot pressing equipment is a powder tablet press with a temperature of 140℃, a pressure of 12 MPa, and a time of 90 s.
[0020] Furthermore, in step (3) above, the gasket is made of polytetrafluoroethylene (PTFE) and has a thickness of 3 mm.
[0021] The present invention also claims protection for a direct formic acid fuel cell prepared by the above-described preparation method.
[0022] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:
[0023] The platinum-nickel catalyst of this invention has three times the catalytic performance of commercial Pt / C catalysts and is less expensive. Its application in direct formic acid fuel cells can significantly improve the performance of direct formic acid fuel cells. Moreover, its simple preparation method theoretically makes it possible to mass-produce at extremely low industrial cost, which is its biggest advantage for large-scale commercial production. Attached Figure Description
[0024] Figure 1 This is a photograph of the membrane electrode from Example 2.
[0025] Figure 2 This is a photograph of the direct formic acid fuel cell of Example 2;
[0026] Figure 3 This is a physical image of the car model in Example 3;
[0027] Figure 4 The CV cycle diagram for 0.5M sulfuric acid + 0.5M HCOOH is shown.
[0028] Figure 5 This is the CV-CO dissolution peak;
[0029] Figure 6 The curve for the ECSA calculation results. Detailed Implementation
[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0031] Example 1
[0032] The preparation method of platinum-nickel catalyst specifically includes the following steps:
[0033] (1) Mix 1000 mg polyvinylpyrrolidone (mW=30000), 290 mg glycine, 158 mg chloroplatinic acid, and 12.88 mg nickel chloride in 25 mL of deionized water and stir for 5 min. Then, sonicate the mixture in an ultrasonic instrument to obtain a uniform yellow solution.
[0034] (2) Add 15 mg of sodium borohydride as a reducing agent to react, then centrifuge at 10000 r / min for 8 min, and wash the separated product with acetone to purify it, thus obtaining the platinum-nickel catalyst.
[0035] Example 2
[0036] The preparation method of a direct formic acid fuel cell specifically includes the following steps:
[0037] (1) Add 5 wt% Nafion solution, isopropanol and water as dispersants to the platinum-nickel catalyst prepared in Example 1 to form a mixture. The mass ratio of platinum-nickel catalyst to Nafion solution is 7:3. Disperse ultrasonically for 1.0 h to obtain a catalyst slurry with a solid content of 1%.
[0038] (2) Using an airbrush, the catalyst slurry was sprayed onto the microporous layers of the anode and cathode of the direct formic acid fuel cell at a working pressure of 1.5 MPa. First, the carbon paper coated with the catalyst slurry was placed in a drying oven and dried at 60°C for 2.0 h. Then, a 5 wt% Nafion solution was brushed onto the treated anode and cathode electrode surfaces. The coated surfaces were then placed face-to-face on both sides of the Nafion membrane, clamped together with metal plates, and placed in a powder press at 140°C and 12 MPa for 90 s to obtain the membrane electrode assembly (e.g., ...). Figure 1 (as shown)
[0039] (3) Use a 3 mm thick PTFE gasket to sandwich the membrane electrode in the middle, place it between two graphite plates, and then assemble the upper end plate on both sides and fix it with nuts to obtain a direct formic acid fuel cell (e.g. Figure 2 (As shown).
[0040] Example 3
[0041] The assembly of the toy car model includes the following steps:
[0042] The vehicle model consists of a direct methanol fuel cell prepared in Example 2, a formic acid storage device, a peristaltic pump, and a transmission transducer. Formic acid is pumped from the storage device into the direct methanol fuel cell via the peristaltic pump. The direct methanol fuel cell generates electricity through a reaction, which in turn propels the vehicle (e.g., ...). Figure 3 (As shown).
[0043] Performance testing
[0044] 1. Electrochemical performance test of formic acid oxidation
[0045] Before conducting electrochemical performance tests on formic acid oxidation, the catalyst surface in Example 1 needs to be activated to remove adsorbed contaminants. First, the working electrode is subjected to cyclic voltammetry scans in an Ar-saturated 0.5 M H₂SO₄ or 0.1 M HClO₄ solution within a potential range of 0 V to 1.2 V (vs. RHE) at a scan rate of 50 mV / s until the cyclic voltammetric curves completely overlap, thus obtaining a clean working electrode surface.
[0046] The electrocatalytic oxidation of formic acid was tested using a three-electrode system: a platinum wire electrode as the counter electrode, an Ag / AgCl electrode as the reference electrode, and a glassy carbon electrode coated with a catalyst film as the working electrode. First, Ar was bubbled into a 0.5 M H₂SO₄ + 0.5 M HCOOH or 0.1 M HClO₄ + 0.5 M HCOOH solution for 30 min to remove oxygen. Then, the catalyst was activated. After activation, cyclic voltammetry was performed in Ar-saturated 0.5 M H₂SO₄ + 0.5 M HCOOH or 0.1 M HClO₄ + 0.5 M HCOOH solutions within a potential range of 0 V to 1.2 V (vs. RHE) at a scan rate of 50 mV / s to obtain the polarization curves for the electrochemical oxidation of formic acid. The results are shown below. Figure 4 As shown.
[0047] Depend on Figure 4 It can be seen that the platinum-nickel catalyst in Example 1 has excellent formic acid oxidation performance.
[0048] 2. CO dissolution voltammetry test
[0049] CO dissolution voltammetry was performed in 0.5 M H₂SO₄ or 0.1 M HClO₄ solution. First, Ar was bubbled through the solution for 30 min to remove oxygen. Then, CO (10% CO, 90% Ar) was bubbled through the solution for 30 min at a constant potential of -0.15 V (vs. Ag / AgCl). CO would be monolayer adsorbed onto the catalyst surface. Unadsorbed CO was removed by bubbling with Ar for 15 min. Then, cyclic voltammetry (CV) scans were performed in an Ar atmosphere within a potential range of 0 V to 1.2 V (vs. RHE) at a scan rate of 50 mV / s, for at least 3 cycles. The results are as follows: Figure 5 As shown.
[0050] Depend on Figure 5 It can be seen that the CO dissolution voltammetry test confirmed that the electrocatalytic oxidation of formic acid using the platinum-nickel catalyst in Example 1 mainly follows the direct pathway and has stronger resistance to CO poisoning.
[0051] 3. Calculation of electrochemical active area
[0052] In addition to assessing the catalyst's resistance to CO poisoning, CO dissolution voltammetry can also calculate the catalyst's electrochemical active area (ECSA). The calculation formula is: ECSA = Q CO / (m Pt ×420). Q is obtained by integrating the oxidation peak area of CO. CO m Pt It is the Pt mass on the working electrode, 420 µC cm -2This is the charge required for the oxidation of the monolayer CO adsorbed at the working electrode. The results are as follows: Figure 6 As shown.
[0053] Depend on Figure 6 It can be seen that the performance of the platinum-nickel catalyst in Example 1 is improved by 3 times compared with commercial Pt / C.
[0054] 4. Car model testing
[0055] The hydrogen fuel cell in the car model was replaced with a direct formic acid fuel cell as in Example 2, and the hydrogen reaction device was replaced with a formic acid solution storage device. An electronic peristaltic pump was added to drive the continuous and stable input of formic acid solution into the fuel cell, resulting in the car model prepared in Example 3. Although there is still considerable room for improvement in the modification, the performance of the modified car model is already far superior to that of the original model.
[0056] Furthermore, when the reaction system was expanded to 25 mL, 50 mL, and 100 mL, the catalysts produced showed no significant difference in performance, theoretically indicating the capability for large-scale production.
[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing a platinum-nickel catalyst, characterized in that, Specifically, the following steps are included: (1) Mix polyvinylpyrrolidone, glycine, chloroplatinic acid and nickel chloride in water and stir, then sonicate to obtain a uniform yellow solution; (2) Sodium borohydride was added as a reducing agent to carry out the reaction, centrifuged, washed and purified to obtain the platinum-nickel catalyst.
2. The method for preparing a platinum-nickel catalyst according to claim 1, characterized in that, In step (1), the molecular weight of the polyvinylpyrrolidone is 30,000; the ratio of polyvinylpyrrolidone, glycine, chloroplatinic acid, nickel chloride and water is 1000mg:(190-440)mg:158mg:12.88mg:25mL; and the mixing time is 5min.
3. The method for preparing a platinum-nickel catalyst according to claim 1, characterized in that, In step (2), the amount of sodium borohydride added is 10-15 mg; the centrifugation speed is 10000 r / min and the time is 8 min; the washing and purification reagent is acetone.
4. A platinum-nickel catalyst prepared by the method according to any one of claims 1-3.
5. The application of a platinum-nickel catalyst prepared by any one of claims 1-3 in the preparation of a direct formic acid fuel cell.
6. A method for preparing a direct formic acid fuel cell, characterized in that, Specifically, the following steps are included: (1) Add Nafion solution, isopropanol and water as dispersants to the platinum-nickel catalyst prepared by any one of claims 1-3 to form a mixture, and then ultrasonically disperse it to obtain a uniform catalyst slurry. (2) A catalyst layer slurry is sprayed onto the microporous layer surface of the anode and cathode of the direct formic acid fuel cell, respectively. First, the carbon paper coated with the catalyst layer slurry is dried. Then, a layer of Nafion solution is brushed onto the treated anode and cathode electrode surfaces. The sides coated with the catalyst layer slurry are placed face to face on both sides of the Nafion membrane. The three are clamped with metal plates and hot-pressed to obtain the membrane electrode. (3) Use a gasket to sandwich the membrane electrode in the middle, place it between two graphite plates, and then assemble the upper end plate on both sides and fix it with nuts to obtain the direct formic acid fuel cell.
7. The method for preparing a direct formic acid fuel cell according to claim 6, characterized in that, In step (1), the concentration of the Nafion solution is 5 wt%; the mass ratio of the platinum-nickel catalyst to the Nafion solution is 7:3; the ultrasonic dispersion time is 1.0 h; and the solid content of the catalyst layer slurry is 1%.
8. The method for preparing a direct formic acid fuel cell according to claim 6, characterized in that, In step (2), the spraying equipment is a spray gun with a working pressure of 1.5 MPa; the drying equipment is a drying oven with a temperature of 60℃ and a time of 2.0 h; the hot pressing equipment is a powder tablet press with a temperature of 140℃, a pressure of 12 MPa, and a time of 90 s.
9. The method for preparing a direct formic acid fuel cell according to claim 6, characterized in that, In step (3), the gasket is made of polytetrafluoroethylene and has a thickness of 3 mm.
10. A direct formic acid fuel cell prepared by the preparation method according to any one of claims 6-9.