Preparation of zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst and its application in electrocatalytic oxidation of methanol
The zero-dimensional/two-dimensional electrochemical dealloying PtCuBi/C electrocatalyst, prepared by a combination of solvothermal method and electrochemical dealloying, solves the kinetic and cost problems of platinum-based materials in methanol oxidation reaction and achieves high efficiency and stable catalytic performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ANHUI UNIV
- Filing Date
- 2023-08-08
- Publication Date
- 2026-05-12
AI Technical Summary
Existing platinum-based materials in methanol oxidation catalysts suffer from slow kinetic rates and high costs, and are susceptible to poisoning by carbonaceous intermediates, limiting the large-scale commercial application of direct methanol fuel cells.
Zero-dimensional/two-dimensional electrochemical dealloying PtCuBi/C electrocatalysts were prepared by combining solvothermal method and electrochemical dealloying. Platinum-rich electrocatalysts were synthesized by preferentially dissolving non-precious metals and combining them with inexpensive oxygen-loving metals Cu and Bi to form a unique 0D/2D mixed-dimensional structure, which increases the active sites of Pt and improves the surface electronic environment.
It significantly improves the electrocatalytic performance of the catalyst, reduces the cost, and exhibits higher methanol oxidation activity and stability under alkaline conditions, which is superior to commercial Pt/C catalysts.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrocatalysis in fuel cells, specifically relating to the preparation of a zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst and its application in the electrocatalytic oxidation of methanol. Background Technology
[0002] With escalating environmental problems and dwindling fossil fuel reserves, fuel cells have gained significant attention as a clean energy source. Direct methanol fuel cells (DMFCs) play a crucial role in mitigating environmental pollution and the energy crisis due to their high energy density, convenient storage and transportation, simple structure, and environmental friendliness. However, the slow kinetics and high cost of current methanol oxidation reaction (MOR) catalysts significantly hinder the large-scale commercial application of DMFCs. Although platinum (Pt)-based materials are widely considered one of the most common catalysts for MOR, their scarcity, high cost, and susceptibility to carbonaceous intermediates (especially CO) remain significant challenges. ads Due to their susceptibility to poisoning, platinum (Pt)-based materials face limitations in large-scale applications. Therefore, finding an effective method to manufacture highly efficient platinum-based catalysts for MOR remains a significant challenge.
[0003] Alloying the precious metal platinum with abundant non-precious metals can effectively improve electrocatalytic performance and solve the aforementioned problems. This is because alloying can promote a reduction in the d-band center shift, improve the surface electronic environment, and thus enhance electrocatalytic performance. The presence of inexpensive oxy-loving metals Cu and Bi can promote OH- ads The adsorption of platinum atoms accelerates the elimination of toxic intermediates, thereby further improving the efficiency of MOR. To enhance electrocatalytic activity and maximize the utilization of platinum atoms, researchers are currently focusing on creating unique microstructures that combine various advantages. For example, Du et al. achieved excellent electrocatalytic performance for ethanol and ethylene glycol oxidation by designing a PdPt catalyst with a unique 0D-2D composite structure (JColloidInterface Sci 2022,610,271-279). Wang et al. prepared mixed-dimensional Pt-Ni alloy polyhedral nanochains (AdvMater 2023,35(2),2206508) using ordered nanopolyhedral-nanowire-nanopolyhedral assembly as a bifunctional electrocatalyst for DMFC, effectively mitigating the size effect. Their work provides a new strategy for synthesizing unique spatial structures, which will promote their application prospects in catalytic reactions.
[0004] Electrochemical dealloying is a strategic approach to synthesizing platinum-rich electrocatalysts by preferentially dissolving non-noble metals. This method is widely used in the design of ORR electrocatalysts due to its ease of control, simple operation, and low cost. Strasser and colleagues successfully synthesized a Pt-rich PtCu catalyst via electrochemical dealloying, exhibiting high ORR catalytic activity (J.AM.CHEM.SOC.2007,129,12624-12625). However, research on multi-metal Pt-based alloy MOR electrocatalysts designed using the electrochemical dealloying strategy is limited.
[0005] Based on the above problems, designing a highly active, highly toxic, and low-cost electrocatalyst is of great significance for industrial applications. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing a zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst and its application in the electrocatalytic oxidation of methanol. This invention employs a simple solvothermal method combined with electrochemical dealloying to prepare an 0D / 2DD-PtCuBi / C electrocatalyst that remains stable under environmental conditions. This unique 0D / 2D mixed-dimensional structure possesses abundant atomic interfaces and a large specific surface area. Electrochemical dealloying, by preferentially dissolving non-precious metals to synthesize platinum-rich electrocatalysts, significantly increases the number of Pt active sites, thereby improving the catalytic performance of the electrocatalyst. Furthermore, the introduction of inexpensive oxyphilic metals Cu and Bi reduces costs while enabling the 0D / 2DD-PtCuBi / C electrocatalyst prepared in this invention to exhibit higher catalytic performance for methanol oxidation compared to commercial Pt / C.
[0007] The preparation method of the zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst of the present invention includes the following steps:
[0008] Step 1: Pt acetylacetone salt, Cu hydrated chloride salt and Bi nitrate salt are used as alloy precursors and placed in a reactor with a certain amount of reducing agent. Solvent 1-octadecene and amine solution are added and ultrasonically dissolved to form a uniformly dispersed mixed solution.
[0009] Step 2: Heat the mixed solution obtained in Step 1 from room temperature to 150℃~190℃ and react for 5~60 minutes; after the reaction is completed, cool naturally to room temperature, wash with a mixed solution of ethanol and cyclohexane, centrifuge several times to obtain a black product;
[0010] Step 3: Place activated carbon in cyclohexane and ultrasonically disperse it. Add the black product obtained in step 2 to it and continue to ultrasonically disperse it evenly. Wash it with a mixed solution of acetic acid and ethanol, centrifuge it, and dry it to obtain 0D / 2D PtCuBi / C electrocatalyst.
[0011] Step 4: The 0D / 2D PtCuBi / C electrocatalyst obtained in Step 3 is dispersed in a mixed solution of ethanol and naphthol. After sonication for 20 min, a catalyst ink is obtained. 5 μL of the catalyst ink is transferred to a clean glassy carbon electrode, dried, and then electrochemically dealloyed in a saturated N2 electrolyte of 0.1 M HClO4 at a scan rate of 100 mV / s for 100 cycles, scanning the potential from 0.05 V / RHE to 1.2 V / RHE to form the 0D / 2D D-PtCuBi / C electrocatalyst. The loading of the noble metal Pt is between 10% and 20%, preferably 15% to 20%.
[0012] In step 1, the alloy precursors are Pt(acac)₂, CuCl₂·2H₂O, and Bi(NO₃)₃·5H₂O; the molar ratio of Pt(acac)₂, CuCl₂·2H₂O, and Bi(NO₃)₃·5H₂O in the alloy precursors is 5:10:1 to 10:1:10, preferably 1:2:1. The prepared catalyst has a unique mixed-dimensional structure constructed from zero-dimensional nanoparticles and two-dimensional nanosheets. To explore the origin of the mixed-dimensional formation and excellent performance, while keeping the ratio of the two precursors constant, a smaller amount of a third element is added to obtain a catalyst with a single morphology.
[0013] In step 1, the amine solution is oleylamine; and the volume ratio of oleylamine to 1-octadecene is 3:2. For example, the volume of oleylamine is 3 mL and the volume of 1-octadecene is 2 mL.
[0014] In step 1, the reducing agent is glucose, and the molar ratio of glucose to Pt acetylacetonate is 7:1.
[0015] In step 3, the ratio of activated carbon to black product should be adjusted to ensure that the loading of Pt on the activated carbon by the black product is 15-20%, which is based on the mass of Pt.
[0016] The application of the zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst of this invention is as a highly efficient electrocatalyst in the electrocatalytic oxidation of methanol under alkaline conditions.
[0017] Specifically, a standard three-electrode system was used, with a glassy carbon electrode containing a zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst as the working electrode, a platinum sheet electrode as the counter electrode, and an Hg / HgO electrode as the reference electrode. The methanol oxidation performance of the zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst was tested in an alkaline electrolyte. The alkaline electrolyte contained a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH, which was purified to saturation with nitrogen gas before testing. Cyclic voltammetry was performed at a scan rate of 0.05 V / s in the potential range of -0.9 to 0.3 V, comparing it with commercial Pt / C to investigate changes in its electrocatalytic performance; and a stability test was performed for 2000 seconds at a potential of -0.1 V (relative to Hg / HgO).
[0018] The beneficial effects of this invention are reflected in:
[0019] By combining solvothermal synthesis and electrochemical dealloying strategies, an 0D / 2D D-PtCuBi / C electrocatalyst was successfully prepared by adding platinum acetylacetone and oxophilic metal precursors to an amine and 1-octadecene system. This unique 0D / 2D mixed-dimensional structure possesses abundant atomic interfaces and a large specific surface area. Electrochemical dealloying, through preferential dissolution of non-noble metals to synthesize platinum-rich electrocatalysts, significantly increases the number of Pt active sites, thereby improving the catalytic performance. Furthermore, the introduction of inexpensive oxophilic metals Cu and Bi reduces costs while enabling the 0D / 2D D-PtCuBi / C electrocatalyst prepared in this invention to exhibit higher catalytic performance for methanol oxidation compared to commercial Pt / C. This invention provides an effective design strategy for multi-metal Pt-based alloy catalysts as efficient anode materials in fuel cell applications. Attached Figure Description
[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that these drawings are not limited to the scope of the present invention, but are only an interpretation of the technical solution of the present invention.
[0021] Figure 1 a is a transmission electron microscope (TEM) image of the 0D / 2D PtCuBi / C electrocatalyst prepared in Example 1. Figure 1 b is the corresponding X-ray diffraction image (XRD).
[0022] Figure 2 a is a comparison of the cyclic voltammetry curves of the 0D / 2D PtCuBi / C electrocatalyst prepared in Example 1 and commercial Pt / C in 1 mol / L KOH solution; Figure 2 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0023] Figure 3 A comparison of the chronoamperometry curves of the 0D / 2D PtCuBi / C electrocatalyst prepared in Example 1 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0024] Figure 4 a is a TEM image of the 0D / 2D D-PtCuBi / C electrocatalyst prepared in Example 2. Figure 4 b is a comparison XRD pattern of the 0D / 2DPtCuBi / C electrocatalyst in Example 1 and the 0D / 2D D-PtCuBi / C electrocatalyst in Example 2.
[0025] Figure 5 a is a comparison of the cyclic voltammetry curves of the 0D / 2D D-PtCuBi / C electrocatalyst prepared in Example 2 and commercial Pt / C in 1 mol / L KOH solution. Figure 5 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0026] Figure 6 The figure shows a comparison of the chronoamperometry curves of the 0D / 2D D-PtCuBi / C electrocatalyst prepared in Example 2 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0027] Figure 7 a is a comparison of the cyclic voltammetry curves of the zero-dimensional PtCuBi / C electrocatalyst (OD PtCuBi / C) prepared in Example 3 and commercial Pt / C in 1 mol / L KOH solution; Figure 7 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0028] Figure 8 The figure shows a comparison of the chronoamperometry curves of the OD PtCuBi / C electrocatalyst prepared in Example 3 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0029] Figure 9 a is a comparison of the cyclic voltammetry curves of the two-dimensional PtCuBi / C electrocatalyst (abbreviated as 2D PtCuBi / C) prepared in Example 4 and commercial Pt / C in 1 mol / L KOH solution; Figure 9 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0030] Figure 10The figure shows a comparison of the chronoamperometry curves of the 2D PtCuBi / C electrocatalyst prepared in Example 4 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0031] Figure 11 a is a comparison of the cyclic voltammetry curves of the zero-dimensional electrochemical dealloying PtCuBi / C electrocatalyst (abbreviated as OD D-PtCuBi / C) prepared in Example 5 and commercial Pt / C in 1 mol / L KOH solution; Figure 11 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0032] Figure 12 The figure shows a comparison of the chronoamperometry curves of the OD-PtCuBi / C electrocatalyst prepared in Example 5 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0033] Figure 13 a is a comparison of the cyclic voltammetry curves of the two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst (abbreviated as 2D-PtCuBi / C) prepared in Example 6 and commercial Pt / C in 1 mol / L KOH solution; Figure 13 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0034] Figure 14 The figure shows a comparison of the chronoamperometry curves of the 2D D-PtCuBi / C electrocatalyst prepared in Example 6 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0035] Figure 15 a is a comparison of the cyclic voltammetry curves of the electrocatalysts prepared in Examples 1-6 and commercial Pt / C in 1 mol / L KOH solution; Figure 15 b is a comparison of cyclic voltammetry curves of all catalysts and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0036] Figure 16 The graph shows a comparison of the chronoamperometry curves of the electrocatalysts prepared in Examples 1-6 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. Detailed Implementation
[0037] The technical solution of the present invention will be further described below with reference to specific embodiments. It should be noted that the specific description of the embodiments below is only used to illustrate the synthesis, characterization and performance of the catalyst, and should not be construed as a limitation of the present invention. Those embodiments not directly mentioned in this document may still be obtained by combining these technical solutions.
[0038] Example 1:
[0039] The preparation of the 0D / 2D PtCuBi / C electrocatalyst in this embodiment includes the following steps:
[0040] 1. Weigh 5.0 mg Pt(acac)2, 6.2 mg Bi(NO3)3·5H2O, 4.4 mg CuCl2·2H2O, 16.7 mg glucose and 18.5 mg CTAB into a glass bottle, add 2 mL 1-octadecene and 3 mL oleylamine, tighten the cap, and sonicate for about 30 minutes until the metal precursors are completely dissolved to form a homogeneous mixture.
[0041] 2. Place the above mixture in an oil bath and heat it from room temperature to 170°C, and maintain this temperature for 1 hour.
[0042] 3. After the reaction is complete and the mixture is allowed to cool naturally to room temperature, wash the product with a mixed solution of cyclohexane and ethanol. Centrifuge at 8800 rpm to collect the product. Repeat this process three times. Dissolve the product in 3 mL of cyclohexane for later use.
[0043] 4. Weigh 8.0 mg of activated carbon into a centrifuge tube, add 5 mL of cyclohexane, and sonicate for 30 minutes to disperse the activated carbon evenly.
[0044] 5. Add the product obtained in step 3 to the dispersed activated carbon in step 4, continue to sonicate for 1 hour, centrifuge, wash with a mixed solution of acetic acid and ethanol, and finally wash with ethanol once more. After drying, the 0D / 2D PtCuBi / C electrocatalyst is obtained.
[0045] Figure 1 a is a TEM image of the 0D / 2D PtCuBi / C electrocatalyst prepared in Example 1. It can be seen that the sample exhibits a unique mixed-dimensional composite structure, consisting of 2D nanosheets (white dot coil: type A) and 0D nanoparticles (white dot coil: type B). Figure 1 b is the XRD pattern of the 0D / 2D PtCuBi / C electrocatalyst prepared in Example 1. It can be seen that the XRD diffraction peaks of the sample have shifted significantly relative to pure platinum (JCPDS no. 04-0802), exhibiting a high-angle shift. The results reflect the lattice shrinkage caused by the introduction of Cu and Bi elements into the platinum lattice.
[0046] Figure 2a is a comparison of the cyclic voltammetry curves of the 0D / 2D PtCuBi / C electrocatalyst prepared in Example 1 and commercial Pt / C in 1 mol / L KOH solution; Figure 2 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. It can be seen that compared with the commercial Pt / C (1.22 mg / L) solution... Pt -1 Compared to other catalysts, the 0D / 2D PtCuBi / C electrocatalyst exhibits higher mass activity, reaching 5.75 Amg. Pt -1 The efficiency is 4.71 times that of commercial Pt / C, indicating that the 0D / 2D PtCuBi / C electrocatalyst prepared in Example 1 has better methanol oxidation performance.
[0047] Figure 3 The figure shows a comparison of the chronoamperometry (ChRM) curves of the OD / 2D PtCuBi / C electrocatalyst prepared in Example 1 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. Compared with commercial Pt / C, the OD / 2D PtCuBi / C electrocatalyst prepared in Example 1 still exhibits a higher current density after a 2000-second stability test, indicating that it has higher stability during electrocatalytic oxidation and is suitable for long-term operation.
[0048] Example 2:
[0049] The preparation of the 0D / 2D PtCuBi / C electrocatalyst in this embodiment includes the following steps:
[0050] The 0D / 2D PtCuBi / C electrocatalyst was synthesized according to the preparation method described in Example 1. Keeping other conditions constant, the catalyst powder was dissolved in a mixed solution containing 480 μL of ethanol and 20 μL of Nafion (5%). After ultrasonic treatment for 20 min, the catalyst ink was transferred onto a clean glassy carbon electrode. After drying, the 0D / 2D PtCuBi / C electrocatalyst was electrochemically dealloyed in a N2-saturated 0.1M HClO4 electrolyte at a scan rate of 100 mV / s for 100 cycles, thereby forming the 0D / 2DD-PtCuBi / C electrocatalyst.
[0051] Figure 4 Image a is a TEM image of the 0D / 2D D-PtCuBi / C electrocatalyst prepared in Example 2. It can be seen that the sample still exhibits a mixed-dimensional structure. This indicates that the electrochemical dealloying process did not significantly affect the morphology. Figure 4Figure b shows a comparison of the XRD patterns of the OD / 2DPtCuBi / C electrocatalysts in Example 1 and the OD / 2D D-PtCuBi / C electrocatalyst in Example 2. Compared with the OD / 2DPtCuBi / C electrocatalyst in Example 1, the OD / 2D D-PtCuBi / C electrocatalyst in Example 2 exhibits a significant shift in the Pt(111) facet diffraction direction to a lower angle. The observed shift is mainly attributed to the dissolution of non-noble metals caused by electrochemical dealloying, which effectively mitigates the lattice shrinkage of platinum.
[0052] Figure 5 a is a comparison of the cyclic voltammetry curves of the 0D / 2D D-PtCuBi / C electrocatalyst prepared in Example 2 and commercial Pt / C in 1 mol / L KOH solution; Figure 5 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. It can be seen that compared with the commercial Pt / C (1.22 mg / L) solution... Pt -1 Compared to other catalysts, the 0D / 2D D-PtCuBi / C electrocatalyst exhibits higher mass activity, reaching 14.97 Amg. Pt -1 The efficiency is 12.27 times that of commercial Pt / C, indicating that the OD / 2DD-PtCuBi / C electrocatalyst prepared in Example 2 has better methanol oxidation performance.
[0053] Figure 6 The figure shows a comparison of the chronoamperometry (ChRM) curves of the OD / 2DD-PtCuBi / C electrocatalyst prepared in Example 2 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. Compared with commercial Pt / C, the OD / 2DD-PtCuBi / C electrocatalyst prepared in Example 2 still exhibits a higher current density after a 2000-second stability test, indicating that it has higher stability during electrocatalytic oxidation and is suitable for long-term operation.
[0054] Example 3:
[0055] OD PtCuBi / C electrocatalyst was prepared according to the method described in Example 1, keeping other conditions unchanged, except that the mass of Bi(NO3)3·5H2O was changed to 1.0 mg.
[0056] Figure 7 a is a comparison of the cyclic voltammetry curves of the OD PtCuBi / C electrocatalyst prepared in Example 3 and commercial Pt / C in 1 mol / L KOH solution; Figure 7 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. It can be seen that compared with the commercial Pt / C (1.22 mg / L) solution...Pt -1 Compared to other catalysts, the 0D PtCuBi / C electrocatalyst exhibits higher mass activity, reaching 4.57 Amg. Pt -1 The efficiency is 3.75 times that of commercial Pt / C, indicating that the OD PtCuBi / C electrocatalyst prepared in Example 3 has better methanol oxidation performance.
[0057] Figure 8 The figure shows a comparison of the chronoamperometry (ChRM) curves of the OD PtCuBi / C electrocatalyst prepared in Example 3 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. Compared with commercial Pt / C, the OD PtCuBi / C electrocatalyst prepared in Example 3 still exhibits a higher current density after a 2000-second stability test, indicating that it possesses higher stability during electrocatalytic oxidation and is suitable for long-term operation.
[0058] Example 4:
[0059] 2D PtCuBi / C electrocatalysts were prepared according to the method described in Example 1, keeping other conditions unchanged except for the synthesis steps:
[0060] 1. Weigh 10.0 mg Pt(acac)2, 12.4 mg Bi(NO3)3·5H2O, 16.7 mg glucose and 18.5 mg CTAB into a glass bottle, add 2 mL 1-octadecene and 3 mL oleylamine, tighten the cap, and sonicate for about 30 minutes until the precursors are completely dissolved to form a homogeneous mixture.
[0061] 2. Place the above mixture in an oil bath and heat it from room temperature to 170°C, and maintain this temperature for 1 hour.
[0062] 3. Dissolve 1.0 mg CuCl2·2H2O in a mixture of 1 ml OAM and 1 ml ODE, and add it dropwise to the above glass vial while stirring. Continue the reaction at 170°C for 1 h. The remaining synthesis steps are the same as in Example 1.
[0063] Figure 9 a is a comparison of the cyclic voltammetry curves of the 2D PtCuBi / C electrocatalyst prepared in Example 4 and commercial Pt / C in 1 mol / L KOH solution; Figure 9 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. It can be seen that compared with the commercial Pt / C (1.22 mg / L) solution... Pt -1 Compared to other catalysts, the 2D PtCuBi / C electrocatalyst exhibits higher mass activity, reaching 5.14 Amg. Pt-1 The efficiency is 4.21 times that of commercial Pt / C, indicating that the 2D PtCuBi / C electrocatalyst prepared in Example 4 has better methanol oxidation performance.
[0064] Figure 10 The figure shows a comparison of the chronoamperometry (ChRM) curves of the 2D PtCuBi / C electrocatalyst prepared in Example 4 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. Compared with commercial Pt / C, the 2D PtCuBi / C electrocatalyst prepared in Example 4 still exhibits a higher current density after a 2000-second stability test, indicating that it has higher stability during electrocatalytic oxidation and is suitable for long-term operation.
[0065] Example 5:
[0066] The OD-PtCuBi / C electrocatalyst was prepared according to the method described in Example 2, keeping other conditions unchanged. The OD-PtCuBi / C electrocatalyst synthesized in Example 3 was then subjected to electrochemical dealloying.
[0067] Figure 11 a is a comparison of the cyclic voltammetry curves of the OD D-PtCuBi / C electrocatalyst prepared in Example 5 and commercial Pt / C in 1 mol / L KOH solution; Figure 11 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. It can be seen that compared with the commercial Pt / C (1.22 mg / L) solution... Pt -1 Compared to other catalysts, the 0D D-PtCuBi / C electrocatalyst exhibits higher mass activity, reaching 7.43 Amg. Pt -1 The efficiency is 6.09 times that of commercial Pt / C, indicating that the OD-PtCuBi / C electrocatalyst prepared in Example 5 has better methanol oxidation performance.
[0068] Figure 12 The figure shows a comparison of the chronoamperometry (ChRM) curves of the OD D-PtCuBi / C electrocatalyst prepared in Example 5 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. Compared with commercial Pt / C, the OD D-PtCuBi / C electrocatalyst prepared in Example 5 still exhibits a higher current density after a 2000-second stability test, indicating that it possesses higher stability during electrocatalytic oxidation and is suitable for long-term operation.
[0069] Example 6:
[0070] The 2D PtCuBi / C electrocatalyst was prepared according to the method described in Example 2, keeping other conditions unchanged. The 2D PtCuBi / C electrocatalyst synthesized in Example 4 was then subjected to electrochemical dealloying.
[0071] Figure 13 a is a comparison of the cyclic voltammetry curves of the 2D D-PtCuBi / C electrocatalyst prepared in Example 6 and commercial Pt / C in 1 mol / L KOH solution; Figure 13 b is a comparison of the cyclic voltammetry curves of the two solutions in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. It can be seen that compared with the commercial Pt / C (1.22 mg / L) solution... Pt -1 Compared to other catalysts, the 2D D-PtCuBi / C electrocatalyst exhibits higher mass activity, reaching 7.85 Amg. Pt -1 The efficiency is 6.43 times that of commercial Pt / C, indicating that the 2D D-PtCuBi / C electrocatalyst prepared in Example 6 has better methanol oxidation performance.
[0072] Figure 14 The figure shows a comparison of the chronoamperometry (ChRM) curves of the 2D D-PtCuBi / C electrocatalyst prepared in Example 6 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. Compared with commercial Pt / C, the 2D D-PtCuBi / C electrocatalyst prepared in Example 6 still exhibits a higher current density after a 2000-second stability test, indicating that it possesses higher stability during electrocatalytic oxidation and is suitable for long-term operation.
[0073] Example 7:
[0074] The performance of the prepared catalysts and commercial Pt / C was compared according to Examples 1-6.
[0075] Figure 15 a is a comparison of the cyclic voltammetry curves of the electrocatalysts prepared in Examples 1-6 and commercial Pt / C in 1 mol / L KOH solution; Figure 15 b is a comparison of the cyclic voltammetry curves of all catalysts and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH. It can be seen that compared with commercial Pt / C (1.22 mg / L KOH),... Pt -1 Compared to other catalysts, the 0D / 2D D-PtCuBi / C electrocatalyst exhibits higher mass activity, reaching 14.97 Amg. Pt -1The efficiency is 12.27 times that of commercial Pt / C, indicating that the 0D / 2D D-PtCuBi / C electrocatalyst prepared in Example 2 has the best methanol oxidation performance.
[0076] Figure 16 The graph shows a comparison of the chronoamperometry curves of the electrocatalysts prepared in Examples 1-6 and commercial Pt / C in a mixed solution of 1 mol / L KOH and 1 mol / L CH3OH.
[0077] In summary, the enhanced catalytic activity can be attributed to the following factors: (i) Structural advantages. The unique 0D / 2D hybrid dimensional structure combines the unique small size effect and sufficient exposed atoms of 0D nanoparticles with the high surface area and effective reactant interactions of 2D nanosheets. Furthermore, the presence of 2D nanosheets can alleviate the aggregation problem caused by the small size of 0D nanoparticles. (ii) Electronic modification. This mainly includes two aspects: changes in surface electronic structure caused by electrochemical dealloying, and the acceptance of electrons from adjacent atoms and lattice strain effects. These factors cause the Pt d band center to shift downwards, weakening the binding strength of intermediates at Pt active sites, accelerating reaction kinetics, and significantly improving electrocatalytic performance. (iii) The presence of oxyphilic metals Cu and Bi effectively enhances the adsorption of OH*, which is beneficial for CO. ads These contributions help optimize the CO poisoning pathway while enhancing the electrocatalytic performance of 0D / 2D D-PtCuBi / C.
Claims
1. A method for preparing a zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst, characterized in that... Includes the following steps: Step 1: Pt acetylacetone salt, Cu hydrated chloride salt and Bi nitrate salt are used as alloy precursors and placed in a reactor with a certain amount of reducing agent. Solvent 1-octadecene and amine solution are added and ultrasonically dissolved to form a uniformly dispersed mixed solution. Step 2: Heat the mixed solution obtained in Step 1 from room temperature to 150℃~190℃ and react for 5~60 minutes; after the reaction is completed, cool naturally to room temperature, wash with a mixed solution of ethanol and cyclohexane, centrifuge to obtain a black product; Step 3: Place activated carbon in cyclohexane and ultrasonically disperse it. Add the black product obtained in step 2 to it and continue to ultrasonically disperse it evenly. Wash it with a mixed solution of acetic acid and ethanol, centrifuge it, and dry it to obtain 0D / 2D PtCuBi / C electrocatalyst. Step 4: Disperse the 0D / 2D PtCuBi / C electrocatalyst obtained in Step 3 in a mixed solution of ethanol and naphthol, and sonicate for 20 min to obtain catalyst ink; transfer 5 μL of catalyst ink to a clean glassy carbon electrode, dry it, and then scan it 100 times at a scan rate of 100 mV / s in a saturated N2 electrolyte of 0.1 M HClO4, scanning the potential from 0.05 V / RHE to 1.2 V / RHE to perform electrochemical dealloying, forming 0D / 2D D-PtCuBi / C electrocatalyst.
2. The preparation method according to claim 1, characterized in that: In step 1, the alloy precursor is Pt(acac)2, CuCl2·2H2O and Bi(NO3)3·5H2O; the molar ratio of Pt(acac)2, CuCl2·2H2O and Bi(NO3)3·5H2O in the alloy precursor is 5:10:1 to 10:1:
10.
3. The preparation method according to claim 2, characterized in that: In the alloy precursor, the molar ratio of Pt(acac)2, CuCl2·2H2O, and Bi(NO3)3·5H2O is 1:2:
1.
4. The preparation method according to claim 1, characterized in that: In step 1, the amine solution is oleylamine.
5. The preparation method according to claim 4, characterized in that: The volume ratio of the amine solution to 1-octadecene is 3:
2.
6. The preparation method according to claim 1, characterized in that: The reducing agent is glucose.
7. The preparation method according to claim 1, characterized in that: In the 0D / 2D D-PtCuBi / C electrocatalyst, the Pt loading is between 15% and 20%.
8. The application of the zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst prepared by any one of the preparation methods of claims 1-6, characterized in that: The zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst is used as a highly efficient electrocatalyst in the electrocatalytic oxidation of methanol under alkaline conditions.
9. The application according to claim 8, characterized in that: A standard three-electrode system was used, with a glassy carbon electrode containing a zero-dimensional / two-dimensional electrochemical dealloying PtCuBi / C electrocatalyst as the working electrode, a platinum sheet electrode as the counter electrode, and an Hg / HgO electrode as the reference electrode, to carry out the catalytic oxidation of methanol in an alkaline electrolyte.