Preparation of superfine PdInBi alloy nanoparticles and application of superfine PdInBi alloy nanoparticles in electrocatalytic oxidation reaction

Abstract

The invention discloses preparation of superfine PdInBi alloy nano-particles and application of the superfine PdInBi alloy nano-particles in an electrocatalytic oxidation reaction. The superfine alloy nanoparticle catalyst is prepared by adopting a simple solvothermal method, the size of the obtained catalyst is about 4nm, and the catalyst is uniformly dispersed. In addition, due to the nanoscale particle size, the Pd-based catalyst has more proportion of exposed Pd atoms, so that the electro-catalytic performance of the Pd-based catalyst is improved. The precious metal alloying is an effective way for improving the reaction activity and selectivity. According to the multi-metal-based catalyst, the dosage of precious metal can be remarkably reduced, agglomeration of the precious metal is prevented, all the elements regulate and control the electronic structure through the synergistic effect, meanwhile, combination of different metal atoms can form new active sites on the surface of the catalyst, and therefore the activation energy of the reaction is reduced. Compared with a Pd / C catalyst, the catalyst provided by the invention has higher catalytic performance on ethylene glycol oxidation reaction.

Description

Technical Field

[0001] The present invention belongs to the field of fuel cell electrocatalysis, and specifically relates to the preparation of ultrafine PdInBi alloy nanoparticles and their application in the electrocatalytic oxidation reaction of ethylene glycol. Background Art

[0002] Driven by the shortage of fossil energy, the development of efficient, low-carbon energy conversion technologies has become a global consensus. As a clean energy device, direct ethylene glycol fuel cells (DEGFCs) offer advantages such as high energy conversion efficiency, environmental friendliness, and ease of transportation. Compared to the carbon emissions and expensive purification costs associated with the production of methanol and ethanol, ethylene glycol is widely available and inexpensive, and can be synthesized from biomass (glycerol and cellulose) through catalytic conversion. This makes direct ethylene glycol fuel cells (DEGFCs) a promising energy device. Ethylene glycol theoretically possesses high mass energy density and fuel efficiency. Its molecular structure contains two hydroxyl groups, which readily adsorb onto the catalyst surface in alkaline environments. These groups, through synergistic effects, promote C—C bond cleavage, resulting in a high proportion of complete oxidation (C1) pathways. However, the slow reaction kinetics at low temperatures, the electrochemical reaction's preference for the inefficient partial oxidation (C2) pathway, and catalyst poisoning caused by the generation of intermediates such as formic acid and carbon monoxide during the reaction are major obstacles to the large-scale commercialization of DEGFCs.

[0003] Noble metals (Pt, Pd, Au, Ru) are often used in electrocatalytic reactions due to their unique electronic structure, high catalytic activity and high stability. Pd has lower cost and relatively abundant reserves compared to Pt. However, traditional Pd nanocatalysts are easily poisoned in electrocatalytic reactions, thereby reducing or losing active sites, and have no specific selection for the reaction pathway, which greatly reduces the catalytic effect. In recent years, many studies have shown that alloying precious metals is an effective way to improve reaction activity and selectivity. Multi-metal-based catalysts can significantly reduce the amount of precious metals used and prevent the agglomeration of precious metals. Each element regulates the electronic structure through synergistic effects, and the combination of different metal atoms will form new active sites on the catalyst surface, thereby reducing the activation energy of the reaction. The introduction of oxygen-philic elements can better improve the electronic structure of Pd and, at the same time, promote the formation of surface hydroxyl groups OH *The formation of species, thereby oxidizing and eliminating CO reaction intermediates on the catalyst surface, is facilitated by the formation of oxidative species. For example, Hu et al. synthesized a PdCuCo trimetallic electrocatalyst via a hydrothermal method. The interaction between the oxophilic Cu and Co metals effectively modulated the alcohol oxidation pathway and reduced catalyst poisoning (Angew. Chem. Int. Ed. 2024, 63, e202400281). Qiao et al. designed an Ir-doped PdCu single crystal concave tetrahedron. Experimental results showed that the improved alkaline EGOR performance was due to the synergistic effect of structure and composition, which accelerated electron transport in the active site. The oxophilic Cu metal improved the electronic structure of the catalyst, promoted the cleavage of the C-C bond, and shifted the reaction to the fully oxidative C1 pathway (Small 2024, 20, e2309226). Therefore, using an oxophilic metal to form an alloy with Pd to modulate the electronic structure of the noble metal itself is a key approach to improving the activity of ethylene glycol oxidation.

[0004] Based on the above problems, designing a highly active, highly toxic and low-cost electrocatalyst has important industrial application significance. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method for ultrafine PdInBi alloy nanoparticles and their application in electrocatalytic oxidation reactions. The present invention uses a simple solvent thermal method to prepare an ultrafine alloy nanoparticle catalyst. The resulting catalyst has a size of about 4 nm and is uniformly dispersed. In addition, the nanoscale particle size provides a higher proportion of exposed Pd atoms, thereby improving the electrocatalytic performance of Pd-based catalysts. Alloying precious metals is an effective way to improve reaction activity and selectivity. Multi-metal-based catalysts can significantly reduce the amount of precious metals used and prevent the agglomeration of precious metals. The various elements in the catalyst regulate the electronic structure through synergistic effects, and the combination of different metal atoms forms new active sites on the catalyst surface, thereby reducing the activation energy of the reaction. Compared with Pd / C catalysts, the catalyst of the present invention exhibits higher catalytic performance for ethylene glycol oxidation reactions.

[0006] The present invention provides a method for preparing ultrafine PdInBi alloy nanoparticles, comprising the following steps: Step 1: placing the alloy precursor, reducing agent, and surfactant in a reactor, adding an amine solution, and ultrasonically dissolving the mixture to form a uniformly dispersed mixed solution; Step 2: The mixed solution obtained in step 1 is heated to 180°C to 200°C and reacted for 1-4 hours; after the reaction is completed, it is naturally cooled to room temperature, washed with a mixed solution of ethanol and cyclohexane, and then carbon-loaded, washed with ethanol, and centrifuged to obtain ultrafine PdInBi alloy nanoparticles.

[0007] In step 1, the alloy precursor is acetylacetonate of Pd, acetylacetonate of In, and acetate of Bi, specifically Pd(acac)2, In(acac)3, and Bi(act)3.

[0008] Furthermore, in the alloy precursor, the molar ratio of Pd acetylacetonate, In acetylacetonate, and Bi acetate is 3: 3: 1: to 3: 3: 5, with the optimal ratio being 3: 3: 3.

[0009] In step 1, the amine solution is oleylamine. The volume of the added amine solution is 6 mL. The reducing agent is glucose, and the added amount is 1.8 to 2.3 times the total mass of the precursor. The surfactant is dimethyl dioctadecyl ammonium chloride, and the added amount is 3.5 to 4.6 times the total mass of the precursor.

[0010] The present invention discloses preparation of ultrafine PdInBi alloy nanoparticles and application thereof in electrocatalytic oxidation.

[0011] Specifically, the PdInBi alloy nanoparticles are loaded on activated carbon and then used as a high-efficiency electrocatalyst during the electrocatalytic oxidation reaction of ethylene glycol under alkaline conditions.

[0012] The loading process includes the following steps: placing the activated carbon in cyclohexane for ultrasonic dispersion, then adding the PdInBi alloy nanoparticles, ultrasonically dispersing them evenly, washing and centrifuging with a mixed solution of acetic acid and ethanol, and drying to obtain ultrafine PdInBi / C NPs electrocatalyst; the loading amount of the precious metal Pd is between 15% and 20%.

[0013] The electrocatalytic process includes the following steps: A standard three-electrode system was used, with a glassy carbon electrode coated with PdInBi / C NPs electrocatalyst as the working electrode, a carbon rod electrode as the counter electrode, and a Hg / HgO electrode as the reference electrode, to carry out the catalytic oxidation reaction of ethylene glycol in an alkaline electrolyte.

[0014] The alkaline electrolyte is a mixed solution containing 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0015] Nitrogen was purged to saturation before testing. Cyclic voltammetry was performed at a scan rate of 0.05 V / s over a potential range of -0.9 to 0.3 V, comparing the potential with commercial Pd / C to investigate changes in electrocatalytic performance. Stability testing was also performed at a potential of -0.1 V (vs. Hg / HgO) for 2000 seconds.

[0016] The beneficial effects of the present invention are embodied in: The present invention uses a simple solvothermal method to prepare an ultrafine PdInBi alloy nanoparticle catalyst. The size of the obtained catalyst is about 4 nm and is uniformly dispersed. In addition, the nanoscale particle size provides a higher proportion of exposed Pd atoms, thereby improving the electrocatalytic performance of the Pd-based catalyst. Alloying precious metals is an effective way to improve reaction activity and selectivity. Multi-metal-based catalysts can significantly reduce the amount of precious metals used and prevent the agglomeration of precious metals. The various elements in the catalyst regulate the electronic structure through synergistic effects, and the combination of different metal atoms forms new active sites on the catalyst surface, thereby reducing the activation energy of the reaction. Compared with Pd / C catalysts, the catalyst of the present invention exhibits higher catalytic performance for ethylene glycol oxidation reactions. The catalyst of the present invention provides an effective design strategy for multi-metal Pd-based alloy catalysts as high-efficiency anode materials in fuel cell applications. It also provides a simple and convenient method for synthesizing ultrafine nanoparticles. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 do not limit the scope of the present invention, but are only used as an explanation of the technical solution of the present invention.

[0018] Figure 1 This is a transmission electron microscope (TEM) image of the PdInBi nanocatalyst prepared in Example 1.

[0019] Figure 2 is the corresponding X-ray diffraction pattern (XRD).

[0020] Figure 3 This is a comparison of the cyclic voltammetry curves of the PdInBi / C nanocatalyst prepared in Example 1 and commercial Pd / C in 1 mol / L KOH solution.

[0021] Figure 4 The figure shows the comparison of the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0022] Figure 5 This is a comparison of the chronoamperometric curves of the PdInBi / C nanocatalyst prepared in Example 1 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0023] Figure 6 This is a comparison of the cyclic voltammetry curves of the PdInBi / C nanocatalyst prepared in Example 2 and Pd / C in 1 mol / L KOH solution.

[0024] Figure 7The figure shows the comparison of the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0025] Figure 8 This is a comparison diagram of the chronoamperometric curves of the PdInBi / C nanocatalyst commercial Pd / C prepared in Example 2 in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0026] Figure 9 This is a comparison diagram of the cyclic voltammetry curves of the PdInBi / C nanocatalyst prepared in Example 3 and Pd / C in 1 mol / L KOH solution.

[0027] Figure 10 The figure shows the comparison of the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0028] Figure 11 This is a comparison of the chronoamperometric curves of the PdInBi / C nanocatalyst prepared in Example 3 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0029] Figure 12 This is a comparison of the cyclic voltammetry curves of the PdIn / C nanocatalyst prepared in Example 4 and commercial Pd / C in 1 mol / L KOH solution.

[0030] Figure 13 The figure shows the comparison of the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0031] Figure 14 This is a comparison of the chronoamperometric curves of the PdIn / C nanocatalyst prepared in Example 4 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0032] Figure 15 This is a comparison of the cyclic voltammetry curves of the PdBi / C nanocatalyst prepared in Example 5 and commercial Pd / C in 1 mol / L KOH solution.

[0033] Figure 16 The figure shows the comparison of the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2.

[0034] Figure 17This is a comparison of the chronoamperometric curves of the PdBi / C nanocatalyst prepared in Example 5 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2. DETAILED DESCRIPTION

[0035] The technical solutions of the present invention are further described below in conjunction with 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 understood as limiting the present invention. Those embodiments not directly mentioned in this article may still be obtained by combining these technical solutions. Example 1

[0036] This embodiment prepares ultrafine PdInBi alloy nanoparticle catalyst, including the following steps: 1. Weigh 8 mg Pd(acac)2, 5.0 mg In(acac)3, 3.0 mg Bi(act)3, 30 mg glucose and 60 mg dimethyldioctadecylammonium chloride into a glass bottle with 6 mL oleylamine. Cover tightly and sonicate continuously for about 30 minutes until the precursor metal salts are completely dissolved to form a uniform mixture.

[0037] 2. Place the above mixture in a reaction vessel, heat from room temperature to 180°C, and maintain for 3 hours.

[0038] 3. After the reaction is completed, cool naturally to room temperature, wash with a mixed solution of cyclohexane and ethanol, and collect the product by centrifugation at 8800 rpm for 8 min. Repeat the operation three times and dissolve the obtained product in 3 mL of cyclohexane for later use.

[0039] 4. Weigh 8.0 mg of activated carbon into a centrifuge tube, add 3 mL of cyclohexane and sonicate for 30 minutes to evenly disperse the activated carbon.

[0040] 5. The product obtained in step 3 was added to the activated carbon dispersed in step 4, and ultrasonication was continued for 1 hour. After centrifugation, the product was washed with acetic acid and cyclohexane, and finally washed once with ethanol. After drying, the product was obtained to obtain an ultrafine PdInBi / C alloy nanoparticle catalyst.

[0041] Figure 1 This is a TEM image of the ultrafine PdInBi / C alloy nanoparticle catalyst prepared in Example 1. It can be seen that the size of the prepared catalyst is about 4 nm and is evenly distributed.

[0042] Figure 2The XRD pattern of the nanocatalyst prepared in Example 1 shows that the XRD diffraction peak of the sample has a significant negative shift relative to that of pure metallic Pd (PDF#46-1043). The negative shift of the diffraction peak can be attributed to the expansion of the Pd lattice due to the introduction of other metal elements, which also proves the successful preparation of the PdInBi / C alloy nanoparticle catalyst.

[0043] Figure 3 This is a cyclic voltammogram of the PdInBi / C alloy nanoparticle catalyst prepared in Example 1 and Pd / C in 1 mol / L KOH solution.

[0044] Figure 4 The cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. It can be seen that the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are similar to those of commercial Pd / C (0.80 A mg Pd -1 ), the prepared PdInBi / C alloy nanoparticle catalyst has a higher mass activity, reaching 10.24 A mg Pd -1 , which is 12.8 times that of commercial Pd / C, indicating that the PdInBi / C alloy nanoparticle catalyst prepared in Example 1 has better ethylene glycol oxidation performance.

[0045] Figure 5 The chronoamperometric curves of the PdInBi / C alloy nanoparticle catalyst prepared in Example 1 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. Compared with commercial Pd / C, the PdInBi / C alloy nanoparticle catalyst prepared in Example 1 still has a higher current density after a stability test of 2000 seconds, indicating that it has higher stability during the electrocatalytic oxidation reaction. Example 2

[0046] The PdInBi / C nanocatalyst was prepared according to the method described in Example 1, keeping other conditions unchanged except that the mass of Bi(act)3 was changed to 1.0 mg. The steps included: 1. Weigh 8 mg Pd(acac)2, 5.0 mg In(acac)3, 1.0 mg Bi(act)3, 30 mg glucose, and 60 mg dimethyldioctadecylammonium chloride into a glass bottle with 6 mL oleylamine. Cover tightly and sonicate continuously for about 30 minutes until the precursor metal salts are completely dissolved to form a uniform mixture.

[0047] 2. Place the above mixture in a reaction vessel, heat from room temperature to 180°C, and maintain for 3 hours.

[0048] 3. After the reaction is completed, cool naturally to room temperature, wash with a mixed solution of cyclohexane and ethanol, and collect the product by centrifugation at 8800 rpm for 8 min. Repeat this operation three times and dissolve the obtained product in 3 mL of cyclohexane for later use.

[0049] 4. Weigh 8.0 mg of activated carbon into a centrifuge tube, add 3 mL of cyclohexane and sonicate for 30 minutes to evenly disperse the activated carbon.

[0050] 5. The product obtained in step 3 was added to the activated carbon dispersed in step 4, and ultrasonication was continued for 1 hour. After centrifugation, the product was washed with acetic acid and cyclohexane, and finally washed once with ethanol. The product was dried to obtain an ultrafine PdInBi / C nanocatalyst.

[0051] Figure 6 This is a cyclic voltammogram of the PdInBi / C nanocatalyst and Pd / C prepared in Example 2 in 1 mol / L KOH solution.

[0052] Figure 7 The cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. It can be seen that the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are similar to those of commercial Pd / C (0.80 A mg Pd -1 ), the prepared PdInBi / C nanocatalyst has a higher mass activity, reaching 8.35 A mg Pd -1 , which is 10.44 times that of commercial Pd / C, indicating that the PdInBi / C nanocatalyst prepared in Example 2 has better ethylene glycol oxidation performance.

[0053] Figure 8 The chronoamperometric curves of the PdInBi / C nanocatalyst prepared in Example 2 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. Compared with commercial Pd / C, the PdInBi / C nanocatalyst prepared in Example 2 still has a higher current density after a stability test of 2000 seconds, indicating that it has higher stability during the electrocatalytic oxidation reaction. Example 3

[0054] This example prepares a PdInBi / C nanocatalyst, keeping all other conditions unchanged except that the mass of Bi(act)3 is changed to 5.0 mg. The following steps are included: 1. Weigh 8 mg Pd(acac)2, 5.0 mg In(acac)3, 5.0 mg Bi(act)3, 30 mg glucose, and 60 mg dimethyldioctadecylammonium chloride into a glass bottle with 6 mL oleylamine. Cover tightly and sonicate continuously for about 30 minutes until the precursor metal salts are completely dissolved to form a uniform mixture.

[0055] 2. Place the above mixture in a reaction vessel, heat from room temperature to 180°C, and maintain for 3 hours.

[0056] 3. After the reaction is completed, cool naturally to room temperature, wash with a mixed solution of cyclohexane and ethanol, and collect the product by centrifugation at 8800 rpm for 8 min. Repeat this operation three times and dissolve the obtained product in 3 mL of cyclohexane for later use.

[0057] 4. Weigh 8.0 mg of activated carbon into a centrifuge tube, add 3 mL of cyclohexane and sonicate for 30 minutes to evenly disperse the activated carbon.

[0058] 5. The product obtained in step 3 was added to the activated carbon dispersed in step 4, and ultrasonication was continued for 1 hour. After centrifugation, the product was washed with acetic acid and cyclohexane, and finally washed once with ethanol. The product was dried to obtain an ultrafine PdInBi / C nanocatalyst.

[0059] Figure 9 This is a cyclic voltammogram of the PdInBi / C nanocatalyst and Pd / C prepared in Example 3 in 1 mol / L KOH solution.

[0060] Figure 10 The cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. It can be seen that the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are similar to those of commercial Pd / C (0.80 A mg Pd -1 ), the prepared PdInBi / C nanocatalyst has a higher mass activity, reaching 9.11 A mg Pd -1 , which are 11.39 times that of Pd / C, respectively, indicating that the PdInBi / C nanocatalyst prepared in Example 3 has better ethylene glycol oxidation performance.

[0061] Figure 11The chronoamperometric curves of the PdInBi / C nanocatalyst prepared in Example 3 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. Compared with commercial Pd / C, the PdInBi / C nanocatalyst prepared in Example 3 still has a higher current density after a stability test of 2000 seconds, indicating that it has higher stability during the electrocatalytic oxidation reaction. Example 4

[0062] The preparation of PdIn / C alloy nanocatalysts in this embodiment includes the following steps: 1. Weigh 8 mg Pd(acac)2, 5.0 mg In(acac)3, 30 mg glucose, and 60 mg dimethyldioctadecylammonium chloride into a glass bottle with 6 mL oleylamine. Cover tightly and sonicate continuously for about 30 minutes until the precursor metal salts are completely dissolved to form a uniform mixture.

[0063] 2. Place the above mixture in a reaction vessel, heat from room temperature to 180°C, and maintain for 3 hours.

[0064] 3. After the reaction is completed, cool naturally to room temperature, wash with a mixed solution of cyclohexane and ethanol, and collect the product by centrifugation at 8800 rpm for 8 min. Repeat this operation three times and dissolve the obtained product in 3 mL of cyclohexane for later use.

[0065] 4. Weigh 8.0 mg of activated carbon into a centrifuge tube, add 3 mL of cyclohexane and sonicate for 30 minutes to evenly disperse the activated carbon.

[0066] 5. The product obtained in step 3 was added to the activated carbon dispersed in step 4, and ultrasonication was continued for 1 hour. After centrifugation, the product was washed with acetic acid and cyclohexane, and finally washed once with ethanol. The product was dried to obtain an ultrafine PdIn / C nanocatalyst.

[0067] Figure 12 The cyclic voltammetry curves of the PdIn / C nanocatalyst and Pd / C prepared in Example 4 in 1 mol / L KOH solution are shown.

[0068] Figure 13 The cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. It can be seen that the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are similar to those of commercial Pd / C (0.80 A mg Pd -1 ) compared with the prepared PdIn / C nanocatalyst, which has a higher mass activity of 5.19 A mg Pd -1, which are 6.49 times that of commercial Pd / C, indicating that the PdIn / C nanocatalyst prepared in Example 4 has better ethylene glycol oxidation performance.

[0069] Figure 14 The chronoamperometric curves of the PdIn / C nanocatalyst prepared in Example 4 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. Compared with commercial Pd / C, the PdIn / C nanocatalyst prepared in Example 4 still has a higher current density after a 2000-second stability test, indicating that it has higher stability during the electrocatalytic oxidation reaction. Example 5

[0070] The present embodiment prepares the PdBi / C nanocatalyst, comprising the following steps: 1. Weigh 8 mg Pd(acac)2, 3.0 mg Bi(act)3, 30 mg glucose, and 60 mg dimethyldioctadecylammonium chloride into a glass bottle with 6 mL oleylamine. Cover tightly with the lid and sonicate continuously for about 30 minutes until the precursor metal salts are completely dissolved to form a uniform mixture.

[0071] 2. Place the above mixture in a reaction vessel, heat from room temperature to 220°C, and maintain for 3 hours.

[0072] 3. After the reaction is completed, cool naturally to room temperature, wash with a mixed solution of cyclohexane and ethanol, and collect the product by centrifugation at 8800 rpm for 8 min. Repeat this operation three times and dissolve the obtained product in 3 mL of cyclohexane for later use.

[0073] 4. Weigh 8.0 mg of activated carbon into a centrifuge tube, add 3 mL of cyclohexane and sonicate for 30 minutes to evenly disperse the activated carbon.

[0074] 5. The product obtained in step 3 was added to the activated carbon dispersed in step 4, and ultrasonication was continued for 1 hour. After centrifugation, the product was washed with acetic acid and cyclohexane, and finally washed once with ethanol. The product was dried to obtain an ultrafine PdBi / C nanocatalyst.

[0075] Figure 15 This is a cyclic voltammogram of the PdBi / C nanocatalyst and Pd / C prepared in Example 5 in 1 mol / L KOH solution.

[0076] Figure 16 The cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. It can be seen that the cyclic voltammetry curves of the two in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are similar to those of commercial Pd / C (0.80 A mg Pd -1) compared with the prepared PdBi / C nanocatalyst, which has a higher mass activity of 6.97A mg Pd -1 , which are 8.71 times that of commercial Pd / C, respectively, indicating that the PdBi / C nanocatalyst prepared in Example 5 has better ethylene glycol oxidation performance.

[0077] Figure 17 The chronoamperometric curves of the PdBi / C nanocatalyst prepared in Example 5 and commercial Pd / C in a mixed solution of 1 mol / L KOH and 1 mol / L (CH2OH)2 are shown. Compared with commercial Pd / C, the PdBi / C nanocatalyst prepared in Example 5 still has a higher current density after a stability test of 2000 seconds, indicating that it has higher stability during the electrocatalytic oxidation reaction.

Claims

1. A method for preparing ultrafine PdInBi alloy nanoparticles, comprising the following steps: Step 1: placing the alloy precursor, reducing agent, and surfactant in a reactor, adding a solvent amine solution, and ultrasonically dissolving to form a uniformly dispersed mixed solution; Step 2: The mixed solution obtained in step 1 is heated to 180°C to 200°C and reacted for 1-4 hours; after the reaction is completed, it is naturally cooled to room temperature, washed with a mixed solution of ethanol and cyclohexane, and then carbon-loaded, washed with ethanol, and centrifuged to obtain ultrafine PdInBi alloy nanoparticles.

2. The preparation method according to claim 1, wherein: In step 1, the alloy precursor is acetylacetonate of Pd, acetylacetonate of In, and acetate of Bi.

3. The preparation method according to claim 2, wherein: In the alloy precursor, the molar ratio of Pd acetylacetonate, In acetylacetonate, and Bi acetate is 3:3:1 to 3:3:

5.

4. The preparation method according to claim 2, wherein: In the alloy precursor, the molar ratio of Pd acetylacetonate, In acetylacetonate, and Bi acetate is 3:3:

3.

5. The preparation method according to claim 1, wherein: In step 1, the amine solution is oleylamine.

6. The preparation method according to claim 1, wherein: In step 1, the reducing agent is glucose, and the surfactant is dimethyldioctadecylammonium chloride.

7. Use of the ultrafine PdInBi alloy nanoparticles prepared by the preparation method according to any one of claims 1 to 6 in the electrocatalytic oxidation of ethylene glycol.

8. The use according to claim 7, characterized in that: The ultrafine PdInBi alloy nanoparticles are loaded on activated carbon and then used as a high-efficiency electrocatalyst in the electrocatalytic oxidation of ethylene glycol under alkaline conditions.

9. The use according to claim 8, characterized in that: The loading process includes the following steps: placing activated carbon in cyclohexane for ultrasonic dispersion, then adding the PdInBi alloy nanoparticles, ultrasonically dispersing them uniformly, washing with a mixed solution of acetic acid and ethanol, centrifuging, and drying to obtain an ultrafine PdInBi / CNPs electrocatalyst; the loading amount of the precious metal Pd is between 15% and 20%.

10. The use according to claim 8, characterized in that: Electrocatalytic process The method comprises the following steps: using a standard three-electrode system, with a glassy carbon electrode coated with a PdInBi / C NPs electrocatalyst as the working electrode, a carbon rod electrode as the counter electrode, and a Hg / HgO electrode as the reference electrode, to carry out a catalytic oxidation reaction of ethylene glycol in an alkaline electrolyte.

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