Fuel cell anti-co-poisoning pt-ru electrocatalyst and method of making same

Abstract

The application relates to the technical field of fuel cells, and particularly relates to a fuel cell CO-poisoning-resistant PtRu electrocatalyst and a preparation method thereof.The preparation method comprises the following steps: uniformly mixing a platinum-ruthenium nanoparticle suspension and a carbon powder suspension, then separating the solid to obtain a catalyst precursor; and annealing the catalyst precursor under a reducing atmosphere, and then cooling to obtain the fuel cell CO-poisoning-resistant PtRu electrocatalyst.The platinum-ruthenium nanoparticles are directly loaded on the carbon material, the loading process is simple and easy to operate, the effect is obvious, the particles are uniformly distributed, and no obvious atomic agglomeration phenomenon occurs.Further, the prepared catalyst has the characteristics of good HOR catalytic effect, high stability, strong CO-poisoning resistance and large-batch preparation, and has great positive significance in the actual fuel cell application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cells, and particularly relates to a fuel cell CO-poisoning-resistant PtRu electrocatalyst and a preparation method thereof. BACKGROUND

[0002] In energy storage and conversion devices, fuel cells, as an important electrochemical energy conversion technology, can directly and efficiently convert chemical energy stored in fuel into electrical energy, and have a wide application prospect. Fuel cells use solid ion exchange membranes to conduct hydroxide ions (OH⁻) or protons (H + ) in the solid-state membrane, and have high safety. Fuel cells have high specific power and specific energy, are environmentally friendly, have no electrolyte leakage, and have fast load response, and thus have great application potential in portable power sources and vehicle power sources.

[0003] Fuel cells undergo hydrogen oxidation reaction (HOR) at the anode and oxygen reduction reaction (ORR) at the cathode. The HOR reaction at the anode uses hydrogen as energy, however, the oxidation reaction rate of hydrogen is relatively low, and a catalyst is needed to accelerate the reaction rate. The hydrogen source for fuel cells is diverse, such as hydrogen produced by electrolysis of water, which has high purity but high cost; more commonly used is gray hydrogen produced by industrial production, but its purity is not high and contains other gases such as carbon monoxide (CO) produced by industrial production. The Pt catalyst or Pt-based alloy catalyst commonly used in fuel cells is easily affected by CO in the hydrogen source, resulting in catalyst poisoning and loss of catalytic performance. This is mainly because CO shows a strong adsorption tendency on the surface of platinum group metals (PGM), and the active sites of the catalyst are easily occupied by CO, leading to catalyst poisoning. Even if the CO content is only 10 μmol / mol, it will seriously affect the HOR performance of the Pt catalyst. To weaken the adsorption of CO on the Pt surface, the composition and morphology of the catalyst can be adjusted, such as adding transition elements to the Pt catalyst to adjust the d-band center of the catalyst, thereby reducing the CO adsorption capacity. At present, the research on CO-poisoning-resistant catalysts is relatively extensive, but the existing technology still has the following shortcomings: (1) platinum-based alloy catalyst nanoparticles are prone to agglomeration at high temperatures during synthesis, resulting in low utilization of surface atoms and directly affecting the CO-poisoning-resistant activity of the catalyst. (2) Platinum and transition elements are prone to phase separation when forming an alloy, and there will be Pt-rich regions and transition element-rich regions in the particles, making it difficult to form an alloy and affecting the synergistic effect between them. (3) The synthesis method of platinum-based alloy catalysts is usually complex and difficult to scale up for macro-preparation.

[0004] Despite the great efforts put into developing fuel cell anode catalysts with high CO tolerance, there are still major challenges in terms of solubility, stability and resistance to poisoning of these catalysts under the influence of CO. Therefore, the prior art remains to be improved and developed. SUMMARY

[0005] In view of the deficiencies of the prior art described above, the purpose of the present application is to provide a fuel cell CO-poisoning-resistant PtRu electrocatalyst and a preparation method thereof, aiming to solve the problem that the existing catalysts are easily affected by CO poisoning in the hydrogen source.

[0006] The technical solution of the present application is as follows:

[0007] In a first aspect, the present application provides a preparation method of a fuel cell CO-poisoning-resistant PtRu electrocatalyst, comprising the following steps:

[0008] mixing the platinum ruthenium nanoparticle suspension and the carbon powder suspension uniformly, and then separating the solid to obtain a catalyst precursor;

[0009] cooling to obtain the fuel cell CO-poisoning-resistant PtRu electrocatalyst.

[0010] In the present application, platinum ruthenium nanoparticles are loaded on carbon materials, and the loading process is simple and easy to operate, with obvious effect, uniform particle distribution and no easy agglomeration. Moreover, the addition of Ru weakens the adsorption and desorption of CO on Pt, and the oxidation starts at low potential, and the surface-adsorbed CO is more easily oxidized, so the catalyst has excellent CO poisoning resistance.

[0011] Further, the platinum ruthenium nanoparticle suspension is prepared by dispersing platinum ruthenium nanoparticles in an organic solvent; and the carbon powder suspension is prepared by dispersing carbon powder in an organic solvent.

[0012] The organic solvent is chloroform.

[0013] Further, the platinum ruthenium nanoparticle suspension and the carbon powder suspension are mixed in a mass ratio of 0.4-0.8:1.

[0014] Further, the temperature of the annealing is 200-800℃, and the holding time is 0.1-10h.

[0015] Further, 250mg of the platinum ruthenium nanoparticles are dispersed in 10-1000mL of the organic solvent.

[0016] The preparation method of the platinum ruthenium nanoparticles comprises the following steps:

[0017] The platinum precursor and the ruthenium precursor are added into a mixed solution consisting of oleylamine, diphenyl ether and o-diphenyl ether, and 1,2-dihydroxydecanediol is added, and the reaction is completed by heating under an inert atmosphere, and the solid is obtained by centrifugation after cooling.

[0018] Further, the platinum precursor is platinum acetylacetonate, and the ruthenium precursor is ruthenium acetylacetonate.

[0019] The molar ratio of the platinum precursor to the ruthenium precursor is 1-3:1-10.

[0020] 10-30 mL of oleylamine, 80-120 mL of diphenyl ether, 5-15 mL of o-diphenyl ether and 0.6-0.7 g of 1,2-dihydroxydecanediol are used per 0.1-3 g of the platinum precursor.

[0021] Further, the inert atmosphere is argon.

[0022] The heating temperature is 200-300℃, and the heating time is 5-100 min.

[0023] The centrifugation is performed by placing the mixture obtained after the reaction in a centrifuge tube of a centrifuge, adding 5 g of anhydrous ethanol per 1 g of the mixture, centrifuging at 8000-12000 rpm for 10-20 min, and then pouring off the supernatant.

[0024] Further, the carbon powder is dispersed in 10-1000 mL of an organic solvent per 250 mg of the carbon powder.

[0025] The carbon powder is obtained by grinding the carbon material after calcining the carbon material at 185℃ for 4 h.

[0026] The carbon material is one or more of Vulcan XC72, KB300, KB600, BP2000, Toray carbon and amorphous carbon.

[0027] Further, the separation of the solid is performed by extraction with n-hexane and drying.

[0028] The reducing atmosphere is an argon-hydrogen atmosphere, and the volume ratio of hydrogen in the argon-hydrogen atmosphere is 5-30%.

[0029] In a second aspect, the application provides a fuel cell CO-poisoning-resistant PtRu electrocatalyst prepared by the preparation method of the fuel cell CO-poisoning-resistant PtRu electrocatalyst according to the first aspect.

[0030] Beneficial effects: The platinum ruthenium particles prepared in the application have nanometer level catalysts. Due to the small average particle size and uniform dispersion of the prepared platinum ruthenium nanoparticles, the platinum ruthenium nanoparticles have the characteristics of good HOR catalytic effect, high stability, excellent CO poisoning resistance and large batch production. Then the platinum ruthenium nanoparticles are directly loaded on the carbon material, and the loading process is very simple and easy to operate, and the effect is obvious, and the particle distribution is uniform, and no obvious atomic agglomeration phenomenon occurs. Due to the small average particle size and uniform dispersion of the prepared platinum ruthenium nanoparticles, the platinum ruthenium nanoparticles have the characteristics of good HOR catalytic effect, high stability, strong CO poisoning resistance and large batch production, which has great positive significance in the actual application of fuel cells. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 TEM image of the PtRu-0 electrocatalyst prepared in Example 1 of the application.

[0032] Figure 2 XRD image of the PtRu-0 electrocatalyst prepared in Example 1 of the application.

[0033] Figure 3 Comparison chart of HOR polarization curves of the catalysts of Comparative Example 1 and Example 1 of the application.

[0034] Figure 4 Comparison chart of CO poisoning resistance curves of the catalysts of Comparative Example 1 and Example 1 of the application.

[0035] Figure 5 TEM image of the PtRu-1 electrocatalyst prepared in Example 2 of the application.

[0036] Figure 6 XRD image of the PtRu-1 electrocatalyst prepared in Example 2 of the application.

[0037] Figure 7 Comparison chart of HOR polarization curves of the catalysts of Comparative Example 1 and Example 2 of the application.

[0038] Figure 8 Comparison chart of CO poisoning resistance curves of the catalysts of Comparative Example 1 and Example 2 of the application.

[0039] Figure 9 TEM image of the PtRu-2 electrocatalyst prepared in Example 3 of the application.

[0040] Figure 10 XRD image of the PtRu-2 electrocatalyst prepared in Example 3 of the application.

[0041] Figure 11 Comparison chart of HOR polarization curves of the catalysts of Comparative Example 1 and Example 3 of the application.

[0042] Figure 12 The anti-CO poisoning curves of the catalysts of Comparative Example 1 and Example 3 of the present application are compared. DETAILED DESCRIPTION

[0043] The present application provides a fuel cell anti-CO poisoning PtRu electrocatalyst and a preparation method thereof. In order to make the purpose, technical solutions and effects of the present application clearer and more explicit, the present application is further described in detail below. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0044] The present application provides a preparation method of a fuel cell anti-CO poisoning PtRu electrocatalyst, which comprises the following steps:

[0045] S1, uniformly mixing a platinum-ruthenium nanoparticle suspension and a carbon powder suspension, and then separating the solid to obtain a catalyst precursor;

[0046] S2, annealing the catalyst precursor under a reducing atmosphere, and then cooling to obtain a fuel cell anti-CO poisoning PtRu electrocatalyst.

[0047] In the present application, platinum-ruthenium nanoparticles are loaded on carbon materials. The loading process is simple and easy to operate, has obvious effect, and the particles are uniformly distributed and not easy to agglomerate. Moreover, the addition of Ru weakens the adsorption and desorption of CO on Pt, and the oxidation starts at a low potential, and the surface-adsorbed CO is more easily oxidized, so the catalyst has excellent anti-CO poisoning property.

[0048] Further, the platinum-ruthenium nanoparticle suspension is prepared by dispersing platinum-ruthenium nanoparticles in an organic solvent; and the carbon powder suspension is prepared by dispersing carbon powder in an organic solvent.

[0049] The organic solvent is chloroform.

[0050] Further, 250 mg of platinum-ruthenium nanoparticles are dispersed in 10-1000 mL of organic solvent, and the dispersion can be uniformly achieved by ultrasonic treatment for 20-30 min.

[0051] Further, the preparation method of the platinum-ruthenium nanoparticles comprises the following steps:

[0052] S0, adding a platinum precursor and a ruthenium precursor into a mixed solution composed of oleylamine, diphenyl ether and o-diphenyl ether, and then adding 1,2-dodecanediol, heating under an inert atmosphere until the reaction is complete, and then centrifuging to obtain the solid to obtain platinum-ruthenium nanoparticles.

[0053] Further, in step S0, the platinum precursor is platinum acetylacetonate, and the ruthenium precursor is ruthenium acetylacetonate.

[0054] The molar ratio of the platinum precursor to the ruthenium precursor is 1-3:1-10.

[0055] 10-30 mL of oleylamine, 80-120 mL of diphenyl ether, 5-15 mL of o-diphenyl ether, and 0.6-0.7 g of 1,2-dodecanediol are used per 0.1-3 g of platinum precursor.

[0056] The present application prepares platinum-ruthenium nanoparticles by a sol-gel method, and makes the Pt atoms of single atoms or ultra-small clusters uniformly dispersed in the Ru system by optimizing the alloy structure, increases the Pt atom and Ru atom interface, thereby inhibiting the aggregation of Ru, improving the Pt and Ru atom catalytic utilization rate, and improving the catalytic performance and stability of HOR.

[0057] Further, in step S0, the inert atmosphere is argon, specifically, before the reaction, air can be discharged by passing in argon for 20-30 min, and the reaction is carried out under the condition of maintaining argon reflux.

[0058] Further, in step S0, the heating temperature is 200-300℃, and the time is 5-100 min.

[0059] Further, in step S0, the cooling can be carried out by natural cooling; after cooling, the centrifugation can be carried out by placing the mixture obtained after the reaction in a centrifuge tube, adding 5 g of anhydrous ethanol per 1 g of the mixture, centrifuging at 8000-12000 rpm for 10-20 min, and discarding the supernatant to obtain the black nanoparticles as the platinum-ruthenium nanoparticles.

[0060] In the present application, the addition of Ru weakens the adsorption and desorption of Pt to CO, and can start oxidation at low potential, making the surface adsorbed CO easier to oxidize, so that the prepared catalyst has excellent CO poisoning resistance. Because the prepared platinum-ruthenium nanoparticles have small average particle size and uniform dispersion, they have the characteristics of good HOR catalytic effect, high stability, excellent CO poisoning resistance, and large batch.

[0061] Further, 250 mg of carbon powder is dispersed in 10-1000 mL of organic solvent, specifically, it can be uniformly dispersed by ultrasonic for 20-30 min.

[0062] Further, the carbon powder is obtained by grinding the carbon material after being calcined at 185℃ for 4h. The carbon material after calcination can be ground until it is uniformly dispersed, and the carbon material can be one or more of Vulcan XC72, KB300, KB600, BP2000, Toray carbon, and amorphous carbon.

[0063] The present application can remove the active agent on the surface of the carbon material by air roasting the carbon material, and the platinum-ruthenium nanoparticles can be better loaded on the surface of the carbon material after air roasting. Specifically, if the air roasting temperature is too low or the air roasting time is too short, the catalyst is not easy to load, and if the air roasting is too much, the carbon material is oxidized, which will affect the loading performance of the carbon material.

[0064] Further, in step S1, the platinum-ruthenium nanoparticle suspension and the carbon powder suspension are mixed in a mass ratio of 0.4-0.8:1.

[0065] In the present application, when the mass ratio of platinum to ruthenium in the platinum-ruthenium nanoparticles is controlled at 0.32-0.4:1, the platinum loading can be controlled at 7%-10% and the ruthenium loading can be controlled at 17%-20% by controlling the mass ratio of the platinum-ruthenium nanoparticles to the carbon powder.

[0066] Further, in step S1, the solid is separated and dried by n-hexane filtration.

[0067] Further, in step S2, the reducing atmosphere is an argon-hydrogen atmosphere, and the volume ratio of hydrogen in the argon-hydrogen atmosphere is 5-30%.

[0068] Further, in step S2, the annealing temperature is 200-800℃, and the holding time is 0.1-10h. In the present application, sintering is performed by annealing to fix the platinum-ruthenium nanoparticles loaded on the surface of the carbon powder.

[0069] The platinum-ruthenium nanoparticles prepared in the present application are directly loaded on the carbon material subjected to air roasting, and the loading process is very simple and easy to operate, the effect is obvious, the particle distribution is uniform, and there is no obvious atomic agglomeration phenomenon.

[0070] The present application also provides a fuel cell CO poisoning resistant PtRu electrocatalyst, which is prepared by the preparation method of the fuel cell CO poisoning resistant PtRu electrocatalyst as described above. In the present application, the prepared platinum-ruthenium particles are catalysts with nanoscale prepared by a sol-gel method. Since the prepared platinum-ruthenium nanoparticles have small average particle size and uniform dispersion, they have the characteristics of good HOR catalytic effect, high stability, strong CO poisoning resistance, and can be mass produced, which has great positive significance in the practical application of fuel cells.

[0071] The following is further illustrated by specific examples.

[0072] Comparative Example 1

[0073] A commercially available platinum carbon catalyst (40% Pt / C) with a platinum loading of 40% is used as Comparative Example 1.

[0074] Example 1

[0075] The preparation method of the PtRu-0 electrocatalyst of Example 1 includes the following steps:

[0076] 0.12 g of platinum acetylacetone and 1.2 g of ruthenium acetylacetone were added to a three-necked flask containing a mixture of 20 mL of oleylamine, 100 mL of diphenyl ether, and 10 mL of o-diphenyl ether, and then 0.63 g of 1,2-dodecanediol was added. After purging with argon for 20 min to remove air, the mixture was heated to 260°C under argon reflux (argon atmosphere) for 30 min. After natural cooling, 5 g of anhydrous ethanol was added per 1 g of the prepared mixture, and then centrifuged at 10,000 rpm for 10 min. The supernatant was discarded, and the obtained black nanoparticles were platinum-ruthenium nanoparticles.

[0077] After KB600 was heated to 185°C and then vacuum dried for 4 h, the carbon powder was obtained by grinding until uniform dispersion. The carbon powder was dispersed in 80 mL of chloroform to obtain a carbon powder suspension.

[0078] The platinum-ruthenium nanoparticles were dispersed in 80 mL of chloroform to obtain a platinum-ruthenium nanoparticle suspension. The platinum-ruthenium nanoparticle suspension and the carbon powder suspension were mixed in a mass ratio of 0.57:1 (platinum-ruthenium nanoparticles:carbon powder), and then uniformly shaken. The mixture was dried by extraction with n-hexane to obtain a catalyst precursor.

[0079] The catalyst precursor was heated to 400°C under an argon-hydrogen atmosphere (hydrogen accounted for 5% of the argon-hydrogen atmosphere) for 1 h, and then naturally cooled to obtain the PtRu-0 electrocatalyst of Example 1.

[0080] The TEM image of the PtRu-0 electrocatalyst prepared in Example 1 is shown in Figure 1 , and the XRD image is shown in Figure 2 .

[0081] The PtRu-0 electrocatalyst prepared in Example 1 was subjected to RED testing. 5 mg of the catalyst was ultrasonically dispersed in 500 μL of ultrapure water to form an ink, and then the ink was dropped on the surface of a platinum-carbon electrode at a rate of 10 μL / cm2. Nafion solution was dropped as an adhesive at a rate of 15 μL / cm2to form a working electrode. In the electrolytic cell, 0.1 M KOH solution was used as the electrolyte, a reversible hydrogen electrode was used as the reference electrode, and a platinum wire was used as the counter electrode. Before each test, the electrolyte was purged with argon, and then saturated with hydrogen. The working electrode was maintained at 0 V for 2 s to eliminate cation adsorption. The HOR polarization curves of the electrocatalysts of Comparative Example 1 and Example 1 were measured by RDE testing in 0.1 M KOH solution saturated with H2at a scan rate of 20 mV / s. The comparison of the measured polarization curves is shown in Figure 3(40% Pt / C is Comparative Example 1 and PtRu-0 is Example 1).

[0082] The Pt / C catalyst of Comparative Example 1 and the PtRu-0 electrocatalyst prepared in Example 1 were subjected to CO poisoning resistance tests. The electrolytic cell containing a 0.1 M KOH solution was purged with argon for 30 min, and a reversible hydrogen prepared in the 0.1 M KOH solution was used as a reference electrode, and a platinum wire was used as a counter electrode, and the working electrode prepared above was used as a three-electrode system. After the reversible hydrogen was prepared, the working electrode was activated at a rate of 50 mV / s between 0.05 V and 0.8 V vs. RHE in a saturated Ar electrolyte until a stable CV curve was obtained. After the activation was completed, the background current was measured, and then a CO curve sweep was performed at a rate of 50 mV / s between -0.05 V and 0.8 V vs. RHE, and the CO sweep curve was obtained at a rotation speed of 900 rpm. The CO sweep curves of Comparative Example 1 and Example 1 are compared in FIG. 2. Figure 4 (40% Pt / C is Comparative Example 1 and PtRu-0 is Example 1).

[0083] Example 2

[0084] The method for preparing the PtRu-1 electrocatalyst of Example 2 includes the following steps:

[0085] 0.12 g of platinum acetylacetonate and 1.20 g of ruthenium acetylacetonate were added to a three-necked flask containing a mixture of 20 mL of oleylamine, 100 mL of diphenyl ether, and 10 mL of o-diphenyl ether, and then 0.63 g of 1,2-dodecanediol was added. The air was removed by purging with argon for 20 min, and then the mixture was heated to 260°C under reflux with argon. After the reaction was completed, the mixture was naturally cooled, 5 g of anhydrous ethanol was added per 1 g of the prepared mixture, and then centrifugation was performed at 10,000 rpm for 10 min. The supernatant was discarded, and the obtained black nanoparticles were the platinum-ruthenium nanoparticles.

[0086] After KB600 was heated to 185°C and then aged for 4 h, the carbon powder was obtained by grinding until it was uniformly dispersed. The carbon powder was dispersed in 80 mL of chloroform to obtain a carbon powder suspension.

[0087] The platinum-ruthenium nanoparticles were dispersed in 80 mL of chloroform to obtain a platinum-ruthenium nanoparticle suspension. The platinum-ruthenium nanoparticle suspension and the carbon powder suspension were mixed in a mass ratio of 0.57:1 of platinum-ruthenium nanoparticles to carbon powder, and then the mixture was uniformly shaken. The mixture was dried by extraction with n-hexane to obtain a catalyst precursor.

[0088] The catalyst precursor was heated to 400°C under argon-hydrogen atmosphere (hydrogen accounted for 5% of the argon-hydrogen atmosphere) for 1 h, naturally cooled, then heated to 185°C under air atmosphere for 1 h, and naturally cooled to obtain the PtRu-1 electrocatalyst of Example 2.

[0089] The TEM image of the PtRu-1 electrocatalyst prepared in Example 2 is shown in Figure 5 The XRD image of the PtRu-1 electrocatalyst prepared in Example 2 is shown in Figure 6

[0090] The PtRu-1 electrocatalyst prepared in Example 2 was subjected to RED test. 5 mg of the catalyst was put into 500 μL of ultrapure water to make ink by ultrasonic, and the ink was dropped on the surface of a platinum carbon electrode at a ratio of 10 μL per square centimeter, and Nafion solution was dropped as an adhesive at a ratio of 15 μL per square centimeter to make a working electrode. A 0.1 M KOH solution was used as an electrolyte in an electrolytic cell, a reversible hydrogen was used as a reference electrode, and a platinum wire was used as a counter electrode. The electrolyte was purged with argon before each test, and then hydrogen was introduced to reach a saturated state, and the working electrode was maintained at 0 V for 2 s to eliminate cation adsorption. The HOR polarization curves of Comparative Example 1 and the PtRu-1 electrocatalyst of Example 2 were measured by RDE test in a 0.1 M KOH solution saturated with H2 at a scan rate of 20 mV / s, and the comparison of the measured polarization curves is shown in Figure 7 (40% Pt / C is Comparative Example 1, and PtRu-1 is Example 2).

[0091] The PtRu-1 electrocatalyst prepared in Example 2 was subjected to CO poisoning resistance test. Argon was introduced into an electrolytic cell containing a 0.1 M KOH solution for 30 min, and a reversible hydrogen was prepared in a 0.1 M KOH solution as a reference electrode, and a platinum wire was used as a counter electrode, and the working electrode prepared above was used as a three-electrode system. After the preparation of the reversible hydrogen was completed, the working electrode was activated at a rate of 50 mV / s between 0.05 V and 0.8 V vs. RHE in a saturated Ar electrolyte until a stable CV curve was obtained. After the activation was completed, the background current was measured, and then a CO curve was scanned at a rate of 50 mV / s between -0.05 V and 0.8 V vs. RHE, and the rotation speed was 900 rpm to obtain a CO scanning curve. The comparison of the CO scanning curves of Comparative Example 1 and Example 2 is shown in Figure 8 (40% Pt / C is Comparative Example 1, and PtRu-1 is Example 2).

[0092] Example 3

[0093] The preparation method of the PtRu-2 electrocatalyst of Example 3 includes the following steps:

[0094] ​Put 0.12 g of acetylacetone platinum and 1.2 g of acetylacetone ruthenium into a three-necked flask containing 20 mL of oleylamine, 100 mL of diphenyl ether and 10 mL of o-diphenyl ether mixed solution, then add 0.63 g of 1,2-dihydroxydecanediol, purge with argon for 20 min to remove air, heat to 260℃ under argon reflux (argon atmosphere) for 30 min, then cool naturally, add 5 g of anhydrous ethanol to every 1 g of the obtained mixture, centrifuge at 10000 rpm for 10 min, and then pour off the supernatant to obtain black nanoparticles, which are platinum-ruthenium nanoparticles.

[0095] After KB600 is heated to 185℃, it is kept empty for 4 h, and then ground to obtain carbon powder. Every 250 mg of the carbon powder is dispersed in 80 mL of chloroform to obtain a carbon powder suspension.

[0096] Every 250 mg of the platinum-ruthenium nanoparticles is dispersed in 80 mL of chloroform to obtain a platinum-ruthenium nanoparticle suspension. The platinum-ruthenium nanoparticle suspension and the carbon powder suspension are mixed in a mass ratio of 0.57:1, and then shaken uniformly. The mixture is dried by extraction with n-hexane to obtain a catalyst precursor.

[0097] The catalyst precursor is heated to 400℃ under an argon-hydrogen atmosphere (the volume ratio of hydrogen in the argon-hydrogen atmosphere is 5%) for 1 h, and then cooled naturally. The catalyst precursor is heated to 185℃ under an air atmosphere for 2 h, and then cooled naturally to obtain the PtRu-2 electrocatalyst of Example 3.

[0098] The TEM image of the PtRu-2 electrocatalyst prepared in Example 3 is shown in Figure 9 , and the XRD image is shown in Figure 10 .

[0099] The PtRu-2 electrocatalyst prepared in Example 3 is subjected to RED testing. 5 mg of the catalyst is put into 500 μL of ultrapure water to prepare ink, and the ink is dropped on the surface of a platinum-carbon electrode at a rate of 10 μL per square centimeter. Nafion solution is dropped as an adhesive at a rate of 15 μL per square centimeter to prepare a working electrode. A 0.1 M KOH solution is used as an electrolyte in an electrolytic cell, a reversible hydrogen electrode is used as a reference electrode, and a platinum wire is used as a counter electrode. Before each test, the electrolyte is purged with argon, and then saturated with hydrogen. The working electrode is maintained at 0 V for 2 s to eliminate cation adsorption. The HOR polarization curves of the PtRu-2 electrocatalyst of Example 3 and the Pt / C electrocatalyst of Comparative Example 1 are measured by RDE testing in a 0.1 M KOH solution saturated with H2 at a scanning speed of 20 mV / s. The comparison of the measured polarization curves is shown in Figure 11 (Figure 40% Pt / C is Comparative Example 1, and PtRu-2 is Example 3).

[0100] The PtRu-2 electrocatalyst prepared in Example 3 was subjected to CO poisoning resistance test. The argon gas was introduced into the electrolytic cell containing 0.1M KOH solution for 30min, and then the reversible hydrogen prepared in 0.1M KOH solution was used as reference electrode, the platinum wire was used as counter electrode, and the working electrode prepared above was used as three-electrode system. After the preparation of reversible hydrogen, the working electrode was activated between 0.05V and 0.8V vs. RHE at a rate of 50mV / s in saturated Ar electrolyte until the stable CV curve was obtained. After the activation, the background current was measured, and then the CO curve scanning was carried out at a rate of 50mV / s between -0.05V and 0.8V vs. RHE, the rotation speed was 900rpm, and the CO scanning curve was obtained. The CO scanning curves of Comparative Example 1 and Example 3 were compared, and the comparison chart was shown in Figure 4 (40% Pt / C was Comparative Example 1, and PtRu-2 was Example 3). Figure 12

[0101] It can be found by comparison that the catalyst prepared by the method of the present application has good catalytic performance, CO poisoning resistance and stability, and even after subsequent air burning, the catalyst does not cause large agglomeration or significant performance decline, and the comprehensive performance is far superior to the general commercial platinum carbon catalyst, and has better use performance and stability in actual application. The catalyst material prepared in the example of the present application has excellent CO poisoning resistance and can realize large-scale preparation of hundreds of grams, is suitable for anode catalyst of fuel cell, and has great practical value in the field of new energy electric vehicles.

[0102] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the present application.​

Claims

1. A method for preparing a PtRu electrocatalyst for CO poisoning resistance in fuel cells, characterized in that, Includes the following steps: The platinum-ruthenium nanoparticle suspension and the carbon powder suspension were mixed evenly, and then the solid was separated to obtain the catalyst precursor. The catalyst precursor was annealed in a reducing atmosphere and then cooled to obtain the PtRu electrocatalyst for CO poisoning resistance in the fuel cell. The platinum-ruthenium nanoparticle suspension is prepared by dispersing platinum-ruthenium nanoparticles in an organic solvent; the carbon powder suspension is prepared by dispersing carbon powder in an organic solvent. The preparation method of the platinum-ruthenium nanoparticles includes the following steps: Platinum and ruthenium precursors were added to a mixed solution of oleylamine, diphenyl ether and o-diphenyl ether, and then 1,2-didecanediol was added. The reaction was heated to completion under an inert atmosphere, and the solid was collected by centrifugation after cooling. The carbon powder is obtained by grinding carbon material after it has been air-fired.

2. The method for preparing the PtRu electrocatalyst for CO poisoning resistance in fuel cells according to claim 1, characterized in that, The organic solvent is chloroform.

3. The method for preparing the PtRu electrocatalyst for CO poisoning resistance in fuel cells according to claim 2, characterized in that, The platinum-ruthenium nanoparticle suspension and the toner suspension are mixed at a mass ratio of 0.4-0.8:

1.

4. The method for preparing the PtRu electrocatalyst for CO poisoning resistance in fuel cells according to claim 1, characterized in that, The annealing temperature is 200-800℃, and the holding time is 0.1-10h.

5. The method for preparing the PtRu electrocatalyst for CO poisoning resistance in fuel cells according to claim 2, characterized in that, Each 250 mg of the platinum-ruthenium nanoparticles is dispersed in 10-1000 mL of organic solvent.

6. The method for preparing the PtRu electrocatalyst for CO poisoning resistance in fuel cells according to claim 5, characterized in that, The platinum precursor is platinum acetylacetonate, and the ruthenium precursor is ruthenium acetylacetonate; The molar ratio of the platinum precursor to the ruthenium precursor is 1-3:1-10; For every 0.1-3g of the platinum precursor, use 10-30mL of oleylamine, 80-120mL of diphenyl ether, 5-15mL of o-diphenyl ether and 0.6-0.7g of 1,2-didecanediol.

7. The method for preparing the PtRu electrocatalyst for CO poisoning resistance in fuel cells according to claim 5, characterized in that, The inert atmosphere is argon; The heating temperature is 200-300℃, and the time is 5-100 minutes; The centrifugation is performed by placing the mixture obtained after the reaction into a centrifuge tube, adding 5g of anhydrous ethanol to every 1g of mixture, centrifuging at 8000-12000rpm for 10-20min, and then discarding the supernatant.

8. The method for preparing the PtRu electrocatalyst for CO poisoning resistance in fuel cells according to claim 2, characterized in that, 250 mg of toner is dispersed in 10-1000 mL of organic solvent; The carbon powder is obtained by grinding carbon material after it has been air-fired at 185°C for 4 hours. The carbon material is one or more of Vulcan XC72, KB300, KB600, BP2000, and Toray carbon.

9. The method for preparing the PtRu electrocatalyst for CO poisoning resistance in fuel cells according to claim 1, characterized in that, The separated solids were dried by vacuum filtration with n-hexane. The reducing atmosphere is an argon-hydrogen atmosphere, in which hydrogen accounts for 5-30% of the volume.

10. A PtRu electrocatalyst for CO poisoning resistance in fuel cells, characterized in that, It is prepared by the method for preparing PtRu electrocatalyst for CO poisoning resistance in fuel cells as described in any one of claims 1-9.

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