Carbon-based catalyst, preparation method and application thereof, and hydrogen fuel cell

Abstract

The present invention relates to a carbon-based catalyst, a preparation method and application thereof, and a hydrogen fuel cell. 1s Among the spectrum peaks, a first characteristic peak exists at 536.2±0.2 eV. The carbon-based catalyst according to the present invention not only has improved activity, but also shows improved long-term activity stability.

Description

Technical Field

[0001] The present invention relates to a carbon-based catalyst and a preparation method and application thereof, and also relates to a hydrogen fuel cell containing the carbon-based catalyst. Background Art

[0002] As we all know, the oxygen reduction reaction (ORR) kinetics in proton exchange membrane fuel cells is slow, and its exchange current density is around 10 -6 A / cm 2 , which is far less than the hydrogen exchange current density at the anode. Therefore, the kinetic activation of the fuel cell mainly occurs in the cathode oxygen reduction reaction. Activation polarization is the largest of the four polarization phenomena (ohmic polarization, concentration polarization, osmotic polarization, and activation polarization). Therefore, the development of catalysts with higher intrinsic activity is increasingly important for improving the efficiency of fuel cells. In addition, since the cost of platinum precious metals accounts for approximately 40% of the total cost of fuel cells, improving the long-term stability of catalysts is also of great significance.

[0003] The properties of the catalyst support are crucial, determining catalyst utilization, electron transfer rate, and ultimately electrode catalyst performance. Currently, widely used catalyst supports are VXC-72 conductive carbon black and Ketjenblack conductive carbon black. While these supports exhibit good performance, they still corrode at high potentials (>1.1V), leading to agglomeration and growth of supported catalyst particles and a reduction in electrochemical surface area. This is primarily due to a low degree of graphitization. Therefore, increasing the graphitization of the carbon support is an important approach to improving stability. Currently reported large-diameter graphene tubes with a high degree of graphitization exhibit very stable performance under acidic conditions, but their relatively low specific surface area results in suboptimal performance in fuel cells. Furthermore, the current preparation process for platinum-carbon catalysts (Pt / C catalysts) typically involves synthesizing Pt nanoparticles and then depositing them onto the carbon support via adsorption. This weak interaction between the nanoparticles and the carbon support makes the catalyst particles easily detached, increasing electron transfer resistance and resulting in a high ORR overpotential.

[0004] These research results show that the morphology, size and surface functional groups or defect sites of carbon supports play an important role in the electrochemical reaction of catalyst nanoparticles, and ultimately determine the performance of the battery, such as activity and stability.

[0005] In the existing technology, the impregnation reduction method is the most commonly used method for preparing Pt / C catalysts. This method directly uses the strong reducing properties of sodium borohydride to reduce and impregnate the Pt / C material. The particle size of the prepared Pt particles is usually around 8-10 nanometers. This method is conducive to large-scale preparation, but the particle size distribution of the catalyst is difficult to control, and the reduction process is relatively intense, which can easily cause environmental safety issues.

[0006] In summary, the preparation of catalysts with high activity and long-term stability remains a technical problem that needs to be urgently solved in proton exchange membrane fuel cells. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a fuel cell catalyst with high activity and long-term stability.

[0008] According to a first aspect of the present invention, the present invention provides a carbon-based catalyst comprising a carbonaceous support and a platinum element supported on the carbonaceous support, wherein the O 1s In the spectrum, the first characteristic peak exists at 536.2±0.2 eV.

[0009] According to a second aspect of the present invention, the present invention provides a method for preparing a carbon-based catalyst, the method comprising the following steps:

[0010] Step S1, soaking the carbon-based raw material in an organic solvent to obtain a first carbon-based material, wherein the organic solvent is a ketone solvent;

[0011] Step S2, contacting the first carbon-based material with an oxidant to obtain a second carbon-based material, wherein the oxidant is one or more selected from peroxides;

[0012] Step S3, contacting the second carbon-based material with nitric acid to obtain a third carbon-based material;

[0013] Step S4, calcining the third carbon-based material in an inert atmosphere to obtain a carbonaceous support, wherein the calcination temperature is 800-1800° C.;

[0014] Step S5, dispersing the carbonaceous support and the platinum precursor in an aqueous phase, adding a pH adjuster to the aqueous phase to adjust the pH value of the aqueous phase to alkaline, and obtaining an aqueous dispersion;

[0015] Step S6: contacting the aqueous dispersion with a reducing agent to reduce at least a portion of the platinum precursor to metallic platinum. The reducing agent is an acidic organic reducing agent. The molar ratio of the reducing agent to the platinum precursor is 4-1000:1. The platinum precursor is calculated as platinum element.

[0016] According to a third aspect of the present invention, the present invention provides a carbon-based catalyst prepared by the method described in the second aspect of the present invention.

[0017] According to a fourth aspect of the present invention, the present invention provides use of the carbon-based catalyst described in the first aspect or the third aspect of the present invention in a fuel cell.

[0018] According to a fifth aspect of the present invention, the present invention provides a hydrogen fuel cell, wherein the anode and / or cathode of the hydrogen fuel cell contains the carbon-based catalyst described in the first aspect or the third aspect.

[0019] The carbon-based catalyst according to the present invention not only has improved activity but also shows improved long-term activity stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The XPS spectra of the carbon-based catalysts prepared in Example 1, Comparative Example 1 and Comparative Example 2 are shown.

[0021] Figure 2 This is the ORR stability test curve of the carbon-based catalyst prepared in Example 1. DETAILED DESCRIPTION

[0022] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0023] According to a first aspect of the present invention, the present invention provides a carbon-based catalyst comprising a carbonaceous support and a platinum element supported on the carbonaceous support.

[0024] According to the carbon-based catalyst of the present invention, the O 1s The first characteristic peak is at 536.2±0.2eV. 1s Based on the total amount of O in the carbon-based catalyst, the O 1s The content of CO is 3-5 mol%, preferably 3.5-5 mol%. The first characteristic peak corresponds to the isolated CO molecules and / or CO2 molecules adsorbed on the carbon-based catalyst. Spectral peak of oxygen in the group.

[0025] According to the carbon-based catalyst of the present invention, the O 1sIn the spectrum peak, there is a second characteristic peak at 532±0.4eV and a third characteristic peak at 533.5±0.2eV. The second characteristic peak is The third characteristic peak is the characteristic peak of oxygen in C-OH. The carbon-based catalyst according to the present invention is characterized by O measured by X-ray photoelectron spectroscopy. 1s Based on the total amount of O in the carbon-based catalyst, the O 1s The content of O is 55-70 mol%, preferably 60-65 mol%. Preferably, the O content is 55-70 mol%, preferably 60-65 ... 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s More preferably, the molar ratio of O measured by X-ray photoelectron spectroscopy is 1.4-2.2:1. 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s The molar ratio of O is 1.6-2.1:1. Further preferably, the O 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s The molar ratio is 1.7-2:1.

[0026] In the present invention, the “first”, “second” and “third” appearing before the “characteristic peak” are used to distinguish the characteristic peaks appearing at different positions, so as to more clearly describe the characteristic peaks appearing at different positions. The “first”, “second” and “third” do not have any special limiting effect on the “characteristic peak” itself.

[0027] According to the carbon-based catalyst of the present invention, the surface oxygen content of the carbon-based catalyst is 5 mol% or more, based on the total amount of surface elements of the carbon-based catalyst determined by X-ray photoelectron spectroscopy, and the surface oxygen content is determined by X-ray photoelectron spectroscopy. Preferably, the surface oxygen content of the carbon-based catalyst is 5-7 mol% based on the total amount of surface elements of the carbon-based catalyst determined by X-ray photoelectron spectroscopy. More preferably, the surface oxygen content of the carbon-based catalyst is 5.2-6.2 mol% based on the total amount of surface elements of the carbon-based catalyst determined by X-ray photoelectron spectroscopy.

[0028] In the present invention, the content of oxygen element and the content of each oxygen species on the surface of the carbon-based catalyst are measured by X-ray photoelectron spectroscopy. The specific method is as follows:

[0029] (1) performing X-ray photoelectron spectroscopy analysis on the carbon-based catalyst to obtain an X-ray photoelectron spectrum, and taking the percentage of the peak area of ​​the 1s spectrum peak of the oxygen element to the sum of the peak areas of the 1s spectrum peaks of each element as the molar content of the oxygen element;

[0030] (2) The O1s peak in the X-ray photoelectron spectrum was separated, and the characteristic peak at 536.2±0.2eV was the first characteristic peak, corresponding to the isolated CO molecules and / or CO2 molecules adsorbed on the carbon-based catalyst. Oxygen in the group; the characteristic peak appearing at 532±0.4eV is the second characteristic peak, corresponding to The characteristic peak appearing at 533.5±0.2eV is the third characteristic peak, corresponding to the oxygen in the C-OH group, and the percentage value of the peak area of ​​a characteristic peak to the sum of the peak areas of all characteristic peaks is taken as the content of the oxygen species corresponding to the characteristic peak.

[0031] According to the carbon-based catalyst of the present invention, based on the total amount of the carbon-based catalyst, the content of the platinum element is 0.1-80 weight %, the content of the carbonaceous carrier is 20-99.9 weight %, and the carbonaceous carrier is calculated in terms of carbon element. Preferably, based on the total amount of the carbon-based catalyst, the content of the platinum element is 10-60 weight %, the content of the carbonaceous carrier is 40-90 weight %, and the carbonaceous carrier is calculated in terms of carbon element. More preferably, based on the total amount of the carbon-based catalyst, the content of the platinum element is 20-50 weight %, the content of the carbonaceous carrier is 50-80 weight %, and the carbonaceous carrier is calculated in terms of carbon element. Further preferably, based on the total amount of the carbon-based catalyst, the content of the platinum element is 30-45 weight %, the content of the carbonaceous carrier is 55-70 weight %, and the carbonaceous carrier is calculated in terms of carbon element.

[0032] In the present invention, the contents of platinum element and carbonaceous carrier in the carbon-based catalyst are determined by inductively coupled plasma spectroscopy (ICP) method.

[0033] According to the carbon-based catalyst of the present invention, the carbonaceous support is conductive carbon black. Preferred examples of the conductive carbon black may include, but are not limited to, one or more of Vulcan XC72, Ketjen EC300J, Ketjen EC600J, Blackpearls 2000, and Blackpearls 3000. According to the carbon-based catalyst of the present invention, the specific surface area of ​​the carbonaceous support is preferably 200-2000 m 2 / g, more preferably 250-1500m 2 According to the carbon-based catalyst of the present invention, the specific surface area of ​​the carbonaceous carrier is preferably 200-2000m 2 / g, more preferably 250-1500m 2 / g.

[0034] In the present invention, the specific surface area is measured using the BET (Brief Estimation of Surface Area and Pore Size) method.

[0035] According to a second aspect of the present invention, the present invention provides a method for preparing a carbon-based catalyst, the method comprising the following steps:

[0036] Step S1, soaking the carbon-based raw material in an organic solvent to obtain a first carbon-based material;

[0037] Step S2, contacting the first carbon-based material with an oxidant to obtain a second carbon-based material;

[0038] Step S3, contacting the second carbon-based material with nitric acid to obtain a third carbon-based material;

[0039] Step S4, calcining the third carbon-based material in an inert atmosphere to obtain a carbonaceous support, wherein the calcination temperature is 800-1800° C.;

[0040] Step S5, dispersing the carbonaceous support and the platinum precursor in an aqueous phase, adding a pH adjuster to the aqueous phase to adjust the pH value of the aqueous phase to alkaline, and obtaining an aqueous dispersion;

[0041] Step S6: contacting the aqueous dispersion with a reducing agent to reduce at least a portion of the platinum precursor to metallic platinum, wherein the reducing agent is an acidic organic reducing agent.

[0042] In step S1, the organic solvent is one or more selected from ketone solvents (such as C3-C5 ketones), preferably acetone. The soaking can be carried out at room temperature or at elevated temperature. Preferably, the temperature of the organic solvent is 50-70°C. The duration of the soaking can be selected according to the soaking temperature. Generally, the duration of the soaking can be 5-12 hours, preferably 6-10 hours. The amount of the organic solvent used is based on the ability to immerse the carbon-based raw material. Generally, the volume ratio of the organic solvent to the carbon-based raw material can be 1-3:1.

[0043] In step S1, after the soaking is completed, the solid phase and the liquid phase can be separated by conventional methods (such as filtration), and the obtained solid phase is dried to obtain the first carbon-based material. The drying can be carried out at a temperature of 80-120°C, and the duration of the drying can be 5-15 hours, preferably 8-12 hours. The drying can be carried out under normal pressure or under reduced pressure.

[0044] In step S2, the oxidant is one or more selected from peroxides. Preferably, the oxidant is one or more selected from hydrogen peroxide and an organic peroxide represented by formula (I):

[0045]

[0046] In formula I, R1 and R2 are each selected from H, C4-C 12 Alkyl, C6-C 12 Aryl, C7-C 12 Aralkyl and R1 and R2 are not H at the same time, and R3 is C4-C 12 Straight or branched alkyl or C6-C 12 of aromatic groups.

[0047] In the present invention, C4-C 12 Specific examples of the alkyl group may include, but are not limited to, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, tert-pentyl, hexyl (including various isomers of hexyl), cyclohexyl, octyl (including various isomers of octyl), nonyl (including various isomers of nonyl), decyl (including various isomers of decyl), undecyl (including various isomers of undecyl) and dodecyl (including various isomers of dodecyl).

[0048] In the present invention, C6-C 12 Specific examples of the aryl group may include, but are not limited to, phenyl, naphthyl, methylphenyl, and ethylphenyl.

[0049] In the present invention, C7-C 12 Specific examples of the aralkyl group may include, but are not limited to, phenylmethyl, phenylethyl, phenyl-n-propyl, phenyl-n-butyl, phenyl-t-butyl, phenylisopropyl, phenyl-n-pentyl, and phenyl-n-butyl.

[0050] Specific examples of the organic peroxide may include, but are not limited to, tert-butyl hydroperoxide, cumene hydroperoxide, ethylbenzene hydroperoxide, cyclohexyl hydroperoxide, dicumyl peroxide, dibenzoyl peroxide, di-tert-butyl peroxide, and dodecyl peroxide.

[0051] Preferably, in step S2, the oxidant is hydrogen peroxide.

[0052] In step S2, the first carbon-based material is contacted with an oxidant in a liquid phase in the presence of a liquid dispersion medium. The liquid dispersion medium can be water and / or a C1-C4 alcohol, preferably water. In a preferred embodiment, the oxidant is dissolved in the liquid dispersion medium to form an oxidant solution, and the oxidant solution is contacted with the first carbon-based material. In this preferred embodiment, hydrogen peroxide is preferably used as the oxidant solution. The concentration of hydrogen peroxide in the hydrogen peroxide can be 8-20% by weight.

[0053] In step S2, the contacting is preferably performed at a temperature of 50-70°C. The duration of the contacting can be selected based on the contacting temperature, and is preferably 5-12 hours. The amount of the oxidant can be selected based on the amount of the first carbon-based material. Preferably, the mass ratio of the oxidant to the first carbon-based material is 1-3:1.

[0054] In step S2, after the oxidant treatment is completed, the solid phase and the liquid phase can be separated by conventional methods (such as filtration), and the obtained solid phase is dried to obtain the second carbon-based material. The drying can be carried out at a temperature of 80-120°C, and the duration of the drying can be 5-15 hours, preferably 8-12 hours. The drying can be carried out at normal pressure or under reduced pressure.

[0055] In step S3, the concentration of nitric acid can be 10-30% by weight. The mass ratio of nitric acid to the second carbon-based material is 1-3:1, where the nitric acid is calculated as HNO3. In step S3, the contacting is preferably performed at a temperature of 50-70°C. The duration of the contacting in step S3 can be selected based on the contacting temperature. Preferably, the contacting duration can be 5-12 hours.

[0056] In step S3, after the nitric acid treatment is completed, the solid phase and the liquid phase can be separated by conventional methods (such as filtration), and the obtained solid phase is dried to obtain the third carbon-based material. The drying can be carried out at a temperature of 80-120° C., and the duration of the drying can be 5-15 hours, preferably 8-12 hours. The drying can be carried out under normal pressure or under reduced pressure.

[0057] In step S4, the third carbon-based material is calcined at a temperature of 800-1800°C in an inert atmosphere to obtain a carbonaceous support. Compared to calcination at a temperature below 800°C, the carbon-based catalyst prepared by the method of the present invention exhibits improved electrochemical catalytic activity and stability when calcined at a higher temperature. Preferably, the third carbon-based material is calcined at a temperature of 900-1600°C in an inert atmosphere to obtain a carbonaceous carrier. For example, the calcination temperature can be 900°C, 910°C, 920°C, 930°C, 940°C, 950°C, 960°C, 970°C, 980°C, 990°C, 1000°C, 1010°C, 1020°C, 1030°C, 1040°C, 1050°C, 1060°C, 1070°C, 1080°C, 1090°C, 1100°C, 1110°C, 1120°C, 1130°C, 1140°C, 1150°C, 1160°C, 1170°C, 1180°C, 1190°C, 1200°C, 1210°C, 1220°C, 1230°C, 1240°C, 1250°C, 1260°C, 1270°C, 1280°C, 1290°C, 1300°C, 1310°C, 1320°C, 1330°C, 1340°C ℃, 1220℃, 1230℃, 1240℃, 1250℃, 1260℃, 1270℃, 1280℃, 1290℃, 1300℃, 1310℃, 1320℃, 1330℃, 1340℃, 1350℃, 1360℃, 1370℃, 1380℃, 1390℃, 1400℃, 1410℃, 1420℃, 1430℃, 1440℃, 1450℃, 1460℃, 1470℃, 1480℃, 1490℃, 1500℃, 1510℃, 1520℃, 1530℃, 1540℃, 1550℃, 1560℃, 1570℃, 1580℃, 1590℃ or 1600℃. In a particularly preferred embodiment, the third carbon-based material is calcined at a temperature of 1000-1500° C. in an inert atmosphere, preferably at a temperature of 1000-1200° C., to obtain a carbonaceous carrier. The inactive atmosphere can be an atmosphere formed by nitrogen and / or a zero-group gas, for example, an atmosphere formed by one or more gases selected from nitrogen, argon and helium, preferably a nitrogen atmosphere. The duration of the calcination can be selected according to the calcination temperature. Preferably, the duration of the calcination is 5-20 hours. More preferably, the duration of the calcination is 8-15 hours. Further preferably, the duration of the calcination is 10-12 hours.

[0058] In step S5, the carbonaceous support and the platinum precursor are dispersed in the aqueous phase, and then the pH value of the aqueous dispersion is adjusted to alkaline to obtain an aqueous dispersion. In step S5, the dispersion medium of the aqueous dispersion contains water, and water can be used as the dispersion medium alone, or water can be combined with other dispersion media (such as alcohol) as the dispersion medium. According to the method of the present invention, the dispersion medium of the aqueous dispersion is preferably water, which can reduce costs, reduce the amount of waste liquid, and be more environmentally friendly. In step S5, even if the aqueous dispersion does not use a chelating agent, the carbonaceous support and the platinum precursor can be fully dispersed in the aqueous phase. According to the method of the present invention, in step S5, it is preferably not used a chelating agent, which simplifies operation and reduces costs.

[0059] In step S5, the concentration of the platinum precursor in the aqueous dispersion may be 0.01-0.1 mol / L, preferably 0.01-0.05 mol / L. The platinum precursor may be a conventionally selected one. Preferably, the platinum precursor is one or more selected from chloroplatinic acid, potassium chloroplatinate, and sodium chloroplatinate. More preferably, the platinum precursor is chloroplatinic acid.

[0060] In step S5, the amount of the platinum precursor can be selected according to the platinum content in the expected carbon-based catalyst. Generally, the amount of the platinum precursor is such that in the carbon-based catalyst finally prepared, based on the total amount of the carbon-based catalyst, the content of the platinum element is 0.1-80% by weight, and the content of the carbonaceous carrier is 20-99.9% by weight. Preferably, the amount of the platinum precursor is such that in the carbon-based catalyst finally prepared, based on the total amount of the carbon-based catalyst, the content of the platinum element is 10-60% by weight, the content of the carbonaceous carrier is 40-90% by weight, and the carbonaceous carrier is measured in terms of carbon element. More preferably, the amount of the platinum precursor is such that in the carbon-based catalyst finally prepared, based on the total amount of the carbon-based catalyst, the content of the platinum element is 20-50% by weight, the content of the carbonaceous carrier is 50-80% by weight, and the carbonaceous carrier is measured in terms of carbon element. Further preferably, the amount of the platinum precursor used is such that in the finally prepared carbon-based catalyst, based on the total amount of the carbon-based catalyst, the content of the platinum element is 30-45% by weight, and the content of the carbonaceous carrier is 55-70% by weight, where the carbonaceous carrier is calculated as carbon element.

[0061] In step S5, the carbonaceous support, platinum precursor, and water are dispersed using ultrasound to thoroughly mix the carbonaceous support and platinum precursor. Preferably, the frequency of the ultrasound is 100-1000W. More preferably, the frequency of the ultrasound is 100-500W. The duration of the ultrasonic dispersion can be 0.2-0.5 hours. The carbonaceous support, platinum precursor, and water can be dispersed in a conventional ultrasonic dispersion device.

[0062] In step S5, the pH value of the aqueous phase in which the carbonaceous support and the platinum precursor are dispersed is adjusted to alkaline, preferably the pH value of the aqueous phase is adjusted to 8-14, for example, the pH value of the aqueous phase is adjusted to 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10, 10.1, 10.2, 10.3, 10.4, 10.5 , 10.6, 10.7, 10.8, 10.9, 11, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13, 13.1, 13.2, 13.3, 13.4, 13.5, 13.6, 13.7, 13.8, 13.9 or 14. More preferably, the pH of the aqueous phase is adjusted to 10-13. A pH regulator can be added to the aqueous phase to adjust the pH to alkaline. The pH regulator is preferably one or more of sodium carbonate, potassium carbonate, potassium hydroxide and sodium hydroxide. The pH adjuster is preferably provided in the form of an aqueous solution, and the concentration of the aqueous solution can be conventionally selected and is not particularly limited.

[0063] In step S6, the reducing agent is an acidic organic reducing agent. Preferably, the reducing agent is one or more of citric acid, ascorbic acid, and formic acid. In a more preferred embodiment, the reducing agent is citric acid and / or formic acid. In a particularly preferred embodiment, the reducing agent is formic acid and / or citric acid. In this particularly preferred embodiment, the reducing agent is more preferably formic acid.

[0064] According to the method of the present invention, in step S6, the molar ratio of the reducing agent to the platinum precursor is 4-1000:1, and the platinum precursor is calculated as platinum element. In step S6, the reducing agent is used in excess of the stoichiometric ratio. While reducing the platinum precursor to metallic platinum, the pH of the reaction system is adjusted to an acidic state, so that the platinum precursor and the reducing agent react under acidic conditions. The resulting carbon-based catalyst exhibits enhanced electrochemical catalytic activity. Preferably, the molar ratio of the reducing agent to the platinum precursor is 5-200:1, and the platinum precursor is calculated as platinum element. For example, the molar ratio of the reducing agent to the platinum precursor can be 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1, 100:1, 105:1, 110:1, 115:1, 120:1, 125:1, 130:1 1, 135:1, 140:1, 145:1, 150:1, 155:1, 160:1, 165:1, 170:1, 175:1, 180:1, 185:1, 190:1, 195:1, 200:1, 205:1, 210:1, 215:1, 220:1, 225:1, 230:1, 235:1, 240:1, 245:1, 250:1, 255:1, 260:1, 265:1, 270:1, 275:1, 280:1, 285:1, 290:1 : 1, 295:1, 300:1, 305:1, 310:1, 315:1, 320:1, 325:1, 330:1, 335:1, 340:1, 345:1, 350:1, 355:1, 360:1, 365:1, 370:1, 375:1, 380:1, 385:1, 390:1, 395:1, 400:1, 405:1, 410:1, 415:1, 420:1, 425:1, 430:1, 435:1, 440:1, 445:1, 450:1, 1, 455:1, 460:1, 465:1, 470:1, 475:1, 480:1, 485:1, 490:1, 495:1, 500:1, 505:1, 510:1, 515:1, 520:1, 525:1, 530:1, 535:1, 540:1, 545:1, 550:1, 555:1, 560:1, 565:1, 570:1, 575:1, 580:1, 585:1, 590:1, 595:1 or 600:1, wherein the platinum precursor is calculated as platinum element. More preferably, the molar ratio of the reducing agent to the platinum precursor is 5-100:1, wherein the platinum precursor is calculated as platinum element.Further preferably, the molar ratio of the reducing agent to the platinum precursor is 5-10:1, and the platinum precursor is calculated as platinum element.

[0065] In step S6, the reducing agent is in contact with the aqueous dispersion at 50-150°C. Preferably, in step S6, the reducing agent is in contact with the aqueous dispersion at 80-130°C. More preferably, in step S6, the reducing agent is in contact with the aqueous dispersion at 90-120°C. In step S6, the duration of the reduction reaction can be selected according to the temperature at which the reduction reaction is carried out. Preferably, in step S6, the duration of the aqueous dispersion and the reducing agent can be 4-12 hours, preferably 6-10 hours. In step S6, the reduction reaction is carried out in an inert atmosphere, for example, it can be carried out in an atmosphere of nitrogen and / or group zero gas (such as argon and / or helium),

[0066] According to the method of the present invention, a conventional separation method can be used to separate the solid phase material from the reduction mixture obtained in step S6, and the separated solid phase material is washed with water and dried in sequence to obtain a carbon-based catalyst. Generally, the reduction mixture obtained in step S6 can be subjected to solid-liquid separation by filtering, centrifuging and settling or a combination of two or more to obtain a solid phase material. The drying is preferably carried out at a temperature of 60-120°C, more preferably at a temperature of 80-110°C. The duration of the drying can be 8-24 hours, preferably 10-15 hours. The drying can be carried out at normal pressure or under conditions below atmospheric pressure.

[0067] According to a third aspect of the present invention, the present invention provides a carbon-based catalyst prepared by the method described in the second aspect of the present invention.

[0068] The carbon-based catalyst prepared by the method according to the second aspect of the present invention has an X-ray photoelectron spectrum of O 1s The first characteristic peak is at 536.2±0.2eV. 1s Based on the total amount of O in the carbon-based catalyst, the O 1s The content of is generally 3-5 mol%, preferably 3.5-5 mol%. The first characteristic peak corresponds to the isolated Spectral peak of oxygen in the group.

[0069] The carbon-based catalyst prepared by the method according to the second aspect of the present invention has an X-ray photoelectron spectrum of O 1s In the spectrum peak, there is a second characteristic peak at 532±0.4eV and a third characteristic peak at 533.5±0.2eV. The second characteristic peak is The third characteristic peak is the characteristic peak of oxygen in C-OH. Preferably, the O 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s More preferably, the molar ratio of O measured by X-ray photoelectron spectroscopy is 1.4-2.2:1. 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s The molar ratio of O is 1.6-2.1:1. Further preferably, the O 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s The molar ratio is 1.7-2:1.

[0070] The carbon-based catalyst prepared by the method according to the second aspect of the present invention has a surface oxygen content of 5 mol% or more, based on the total amount of elements on the surface of the carbon-based catalyst measured by X-ray photoelectron spectroscopy. Preferably, the surface oxygen content of the carbon-based catalyst is 5-7 mol%, based on the total amount of elements on the surface of the carbon-based catalyst measured by X-ray photoelectron spectroscopy. More preferably, the surface oxygen content of the carbon-based catalyst is 5.2-6.2 mol%, based on the total amount of elements on the surface of the carbon-based catalyst measured by X-ray photoelectron spectroscopy.

[0071] According to a fourth aspect of the present invention, the present invention provides use of the carbon-based catalyst according to the present invention in a fuel cell.

[0072] According to a fifth aspect of the present invention, the present invention provides a hydrogen fuel cell, the anode and / or cathode of the hydrogen fuel cell contains the carbon-based catalyst according to the present invention.

[0073] The present invention is described in detail below with reference to the embodiments, but the scope of the present invention is not limited thereby.

[0074] In the following examples and comparative examples, X-ray photoelectron spectroscopy (XPS) analysis was performed on an ESCALab250 X-ray photoelectron spectrometer equipped with Thermo Avantage V5.926 software from Thermo Scientific. The excitation source was monochromatic A1 Ka X-ray with an energy of 1486.6 eV and a power of 150 W. The penetration energy used in the narrow scan was 30 eV. The base vacuum during the analysis was 6.5 × 10 -10mbar. Electron binding energy was calibrated using the C1s peak of elemental carbon (284.6 eV). Data processing was performed using ThermoAvantage software, and quantitative analysis was performed using the sensitivity factor method in the analysis module. Samples were dried in a helium atmosphere at 150°C and 1 standard atmosphere for 3 hours before testing.

[0075] In the following examples and comparative examples, the contents of metallic platinum and carbonaceous carrier in the carbon-based catalyst were determined by inductively coupled plasma spectroscopy (ICP).

[0076] In the following examples and comparative examples, the electrochemical activity of the carbon-based catalyst was tested using the rotating disk test method. The catalyst was prepared into a slurry and drop-coated on a glassy carbon electrode with a diameter of 5 mm. The slurry was dried to ensure that the Pt loading on the electrode was between 18 and 22 μg / cm 2 The test conditions for the catalyst polarization curve are: 0.1M HClO4 solution, oxygen saturation, voltage scanning range of 0-1.0V vs RHE, scanning rate of 10mV / s, and rotating disk electrode speed of 1600r / min; the test conditions for the electrochemical active area are: 0.1M HClO4 solution, nitrogen saturation, voltage scanning range of 0-1.0V vs RHE, scanning rate of 50mV / s, and the hydrogen desorption peak area on the curve is integrated.

[0077] Among them, the calculation formula of the electrochemical active area (ECSA) of the carbon-based catalyst is:

[0078]

[0079] Among them, S H is the peak area,

[0080] V is the scan rate, which is 0.05v / s,

[0081] M pt is the mass of Pt dropped on the glassy carbon electrode;

[0082] The mass specific activity (A / mg) of carbon-based catalysts Pt ) is calculated as:

[0083]

[0084] Among them, i k is the kinetic current, in mA / cm 2 , which is calculated based on the KL equation, and the equation form is as follows:

[0085]

[0086] i L is the limiting diffusion current, which is directly read from the ORR curve;

[0087] m Pt is the amount of Pt loaded on the glassy carbon electrode, in mg Pt / cm 2 .

[0088] The following examples and comparative examples involve the following conductive carbon blacks:

[0089] (1) Conductive carbon black with the brand name Ketjen EC300J, purchased from Lion, Japan, with a particle diameter in the range of 50-100 nm and a specific surface area of ​​1200 m 2 / g;

[0090] (2) Conductive carbon black with the brand name Ketjen EC600J, purchased from Lion, Japan, with a particle diameter in the range of 50-100 nm and a specific surface area of ​​1500 m 2 / g;

[0091] (3) Conductive carbon black with the brand name Vulcan XC72, purchased from Carbter, with a particle diameter in the range of 50-100 nm and a specific surface area of ​​260 m 2 / g.

[0092] Examples 1-10 serve to illustrate the present invention.

[0093] Example 1

[0094] (1) Preparation of carrier

[0095] Ketjen EC300J conductive carbon black was soaked in acetone (analytical grade) at 60°C for 8 hours, with a mass ratio of acetone to conductive carbon black of 2:1. After soaking, the solid phase was filtered and dried at 100°C for 8 hours to obtain acetone-soaked carbon black.

[0096] The carbon black soaked in acetone was mixed with 20% hydrogen peroxide (the mass ratio of hydrogen peroxide to carbon black was 2:1) and reacted at 60°C for 12 hours. After the reaction was completed, the reaction mixture was filtered and the solid phase was dried at 100°C for 12 hours to obtain the carbon black treated with hydrogen peroxide.

[0097] The carbon black treated with hydrogen peroxide was mixed with a 30% nitric acid aqueous solution (the mass ratio of HNO3 to carbon black was 2:1) and reacted at 60°C for 12 hours. After the reaction was completed, the reaction mixture was filtered and the resulting solid phase was dried at 100°C for 12 hours to obtain nitric acid-treated carbon black.

[0098] The carbon black treated with nitric acid was calcined at 1100° C. for 10 h in a nitrogen atmosphere to obtain a carbon black carrier.

[0099] (2) Preparation of aqueous dispersion

[0100] 0.6 g of carbon black carrier was added to 150 mL of deionized water, and then chloroplatinic acid (2 mmol) was added, and the resulting mixture was subjected to ultrasonic dispersion at an ultrasonic power of 100 W for 0.5 h.

[0101] Sodium carbonate was added as a pH adjuster to the aqueous dispersion obtained by ultrasonic treatment to adjust the pH of the aqueous dispersion to 13, thereby obtaining an aqueous dispersion.

[0102] (3) Reduction reaction

[0103] The aqueous dispersion was heated to 120°C with stirring, and formic acid (10 mmol) was added as a reducing agent to initiate a reduction reaction. The molar ratio of the reducing agent to chloroplatinic acid was 5:1. After the addition of the reducing agent, the reaction was continued for 10 hours while maintaining the heating conditions.

[0104] After the reaction was complete, the reduction reaction mixture was filtered, the solid phase was collected, and the solid phase was washed with deionized water. The washed solid phase was vacuum dried at 100°C for 12 hours. The dried solid phase was ground to obtain 1g of carbon-based catalyst (particle diameter in the range of 1-3μm). The mass content of platinum in the carbon-based catalyst was determined to be 40%.

[0105] like Figure 1 As shown, XPS analysis shows that the surface oxygen content of the finally prepared carbon-based catalyst is 6.0 mol% based on the total amount of elements on the catalyst surface; based on the total amount of O1s determined by X-ray photoelectron spectroscopy, the content of O1s determined by the first characteristic peak is 4.9 mol%, the content of O1s determined by the second characteristic peak is 32.7 mol%, and the content of O1s determined by the third characteristic peak is 62.4 mol%. The electrochemical properties of the prepared carbon-based catalyst (first cycle) and the electrochemical properties after 5000 cycles (as shown in FIG. 1 ) are measured by a rotating disk test. Figure 2 The specific experimental results are listed in Table 1.

[0106] Comparative Example 1

[0107] The carbon-based catalyst was prepared by the same method as in Example 1, except that step (1) was not performed. Instead, the Ketjen EC300J carbon black used as the raw material in step (1) of Example 1 was directly used in step (2), and then used in step (3) to prepare the carbon-based catalyst (the mass content of platinum in the carbon-based catalyst was determined to be 40.1%). The electrochemical properties of the prepared carbon-based catalyst (first cycle) and the electrochemical properties after 5000 cycles were measured using a rotating disk test. The experimental results are listed in Table 1. Figure 1 As shown, XPS analysis shows that the surface oxygen content is 5.1 mol% based on the total amount of elements on the catalyst surface; Figure 1 As shown, the finally prepared carbon-based catalyst does not have the first characteristic peak. Based on the total amount of O1s measured by X-ray photoelectron spectroscopy, the content of O1s determined by the second characteristic peak is 46.9 mol%, and the content of O1s determined by the third characteristic peak is 53.1 mol%.

[0108] Example 2

[0109] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (1), the carbon black treated with nitric acid was calcined at 1500°C for 10 h in a nitrogen atmosphere to obtain a carbon black carrier. The mass content of platinum in the carbon-based catalyst was determined to be 39.8%. XPS analysis showed that the surface oxygen content of the finally prepared carbon-based catalyst was 6.0 mol% based on the total amount of elements on the catalyst surface; the O content measured by X-ray photoelectron spectroscopy was 2.3 mol%. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 4.9 mol%, which is determined by the second characteristic peak. 1s The content of O is 32.7 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 62.4 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0110] Comparative Example 2

[0111] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (1), the carbon black treated with nitric acid was calcined in a nitrogen atmosphere at 400°C for 10 hours to obtain a carbon black carrier. It was determined that the mass content of platinum in the carbon-based catalyst was 39.7%. The electrochemical properties of the prepared carbon-based catalyst (first cycle) and the electrochemical properties after 5000 cycles were determined by a rotating disk test, and the experimental results are listed in Table 1. XPS analysis showed that the surface oxygen content of the finally prepared carbon-based catalyst was 5.2 mol% based on the total amount of elements on the catalyst surface; Figure 1As shown, the catalyst does not have the first characteristic peak. Based on the total amount of O1s determined by X-ray photoelectron spectroscopy, the content of O1s determined by the second characteristic peak is 45.8 mol%, and the content of O1s determined by the third characteristic peak is 54.2 mol%.

[0112] Example 3

[0113] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (1), the carbon black treated with nitric acid was calcined at 900°C for 10 h in a nitrogen atmosphere to obtain a carbon black carrier. The mass content of platinum in the carbon-based catalyst was determined to be 39.7%. XPS analysis showed that the surface oxygen content of the finally prepared carbon-based catalyst was 5.9 mol%, based on the total amount of elements on the catalyst surface; the O content measured by X-ray photoelectron spectroscopy was 2.3 mol%. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 3.9 mol%, which is determined by the second characteristic peak. 1s The content of O is 33.6 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 62.5 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0114] Example 4

[0115] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (1), the carbon black treated with nitric acid was calcined at 1600°C for 10 h in a nitrogen atmosphere to obtain a carbon black carrier. The mass content of platinum in the carbon-based catalyst was determined to be 39.3%. XPS analysis showed that the surface oxygen content of the finally prepared carbon-based catalyst was 5.8 mol% based on the total amount of elements on the catalyst surface; the O content measured by X-ray photoelectron spectroscopy was 2.3 mol%. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 4.3 mol%, which is determined by the second characteristic peak. 1s The content of O is 34.0 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 61.7 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0116] Example 5

[0117] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (3), the reducing agent was replaced by an equimolar amount of citric acid. The mass content of platinum in the carbon-based catalyst was determined to be 38.9%. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 5.9 mol % based on the total amount of elements on the catalyst surface; the O content was determined by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 4.5 mol%, which is determined by the second characteristic peak. 1s The content of O is 31.9 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 63.6 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0118] Example 6

[0119] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (3), the reducing agent was replaced by an equimolar amount of ascorbic acid. The mass content of platinum in the carbon-based catalyst was determined to be 39.5%. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 5.7 mol % based on the total amount of elements on the catalyst surface; the O content was determined by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 4.2 mol%, which is determined by the second characteristic peak. 1s The content of O is 32.3 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 63.5 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0120] Comparative Example 3

[0121] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (3), the reducing agent was replaced by an equimolar amount of propylene glycol. The mass content of platinum in the carbon-based catalyst was determined to be 40.0%. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 4.1 mol % based on the total amount of elements on the catalyst surface; the O content was determined by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 0 mol%, which is determined by the second characteristic peak. 1s The content of O is 45.9 mol%, which is determined by the third characteristic peak. 1sThe content of carbon is 54.1 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0122] Comparative Example 4

[0123] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (3), the reducing agent was replaced by an equimolar amount of ethylene glycol. The mass content of platinum in the carbon-based catalyst was determined to be 39.9%. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 4.3 mol % based on the total amount of elements on the catalyst surface; the O content was determined by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 0 mol%, which is determined by the second characteristic peak. 1s The content of O is 45.3 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 54.7 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0124] Example 7

[0125] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (3), the molar ratio of formic acid to chloroplatinic acid as the reducing agent was 10:1. The mass content of platinum in the carbon-based catalyst was determined to be 40.0%. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 5.2 mol % based on the total amount of elements on the catalyst surface; the O content was determined by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 4.2 mol%, which is determined by the second characteristic peak. 1s The content of O is 34.5 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 61.3 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0126] Example 8

[0127] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (3), the molar ratio of formic acid to chloroplatinic acid as the reducing agent was 100:1. The mass content of platinum in the carbon-based catalyst was determined to be 39.9%. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 5.3 mol % based on the total amount of elements on the catalyst surface; the O content was determined by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 4.5 mol%, which is determined by the second characteristic peak. 1s The content of O is 32.5 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 63.0 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0128] Comparative Example 5

[0129] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (3), the molar ratio of formic acid to chloroplatinic acid as the reducing agent was 1:1. The mass content of platinum in the carbon-based catalyst was determined to be 37.6%. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 4.1 mol % based on the total amount of elements on the catalyst surface; the O content was determined by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 0 mol%, which is determined by the second characteristic peak. 1s The content of O is 46.3 mol%, which is determined by the third characteristic peak. 1s The content of carbon is 53.7 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0130] Comparative Example 6

[0131] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (3), the molar ratio of formic acid to chloroplatinic acid as the reducing agent was 2:1. The mass content of platinum in the carbon-based catalyst was determined to be 37.6%. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 4.3 mol % based on the total amount of elements on the catalyst surface; the O content was determined by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 0 mol%, which is determined by the second characteristic peak. 1s The content of O is 45.4 mol%, which is determined by the third characteristic peak. 1sThe content of carbon is 54.6 mol%. The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured by rotating disk test. The experimental results are listed in Table 1.

[0132] Example 9

[0133] (1) Preparation of carrier

[0134] The carbon-based catalyst was prepared by the same method as in Example 1, except that in step (1), Ketjen EC 600J conductive carbon black was used as the raw material to prepare the carbon-based catalyst. The mass content of platinum in the carbon-based catalyst was determined to be 40.0%.

[0135] The electrochemical performance of the prepared carbon-based catalyst was measured using a rotating disk test (first cycle) and after 5000 cycles. The experimental results are listed in Table 1. XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 5.3 mol % based on the total amount of elements on the catalyst surface; O was measured by X-ray photoelectron spectroscopy. 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 4.5 mol%, which is determined by the second characteristic peak. 1s The content of O is 32.4 mol%, which is determined by the third characteristic peak. 1s The content is 63.1 mol%.

[0136] Example 10

[0137] (1) Preparation of carrier

[0138] Carbot XC72 conductive carbon black was soaked in acetone (analytical grade) at 60°C for 12 hours, with a mass ratio of acetone to conductive carbon black of 3:1. After soaking, the solid phase was filtered and dried at 100°C for 12 hours to obtain acetone-soaked carbon black.

[0139] The carbon black soaked in acetone was mixed with 8% hydrogen peroxide (the mass ratio of hydrogen peroxide to carbon black was 3:1) and reacted at 60°C for 12 hours. After the reaction was completed, the reaction mixture was filtered and the resulting solid phase was dried at 100°C for 12 hours to obtain hydrogen peroxide-treated carbon black.

[0140] The carbon black treated with hydrogen peroxide was mixed with a 30% nitric acid aqueous solution (the mass ratio of HNO3 to carbon black was 3:1) and reacted at 60°C for 12 hours. After the reaction was completed, the reaction mixture was filtered and the resulting solid phase was dried at 100°C for 12 hours to obtain nitric acid-treated carbon black.

[0141] The carbon black treated with nitric acid was calcined in a nitrogen atmosphere at 1000° C. for 12 h to obtain a carbon black carrier.

[0142] (2) Preparation of aqueous dispersion

[0143] 0.6 g of carbon black carrier was added to 150 mL of deionized water, and then chloroplatinic acid (2 mmol) was added, and the resulting mixture was subjected to ultrasonic dispersion at an ultrasonic power of 100 W for 0.5 h.

[0144] Sodium carbonate was added as a pH adjuster to the aqueous dispersion obtained by ultrasonic treatment to adjust the pH value of the aqueous dispersion to 12, thereby obtaining an aqueous dispersion.

[0145] (3) Reduction reaction

[0146] The aqueous dispersion was heated to 120°C with stirring, and formic acid (10 mmol) was added as a reducing agent to conduct a reduction reaction, wherein the molar ratio of the reducing agent to chloroplatinic acid was 100:1. After the addition of the reducing agent, the heating conditions were maintained unchanged and the reaction was continued for 10 hours.

[0147] After the reaction was completed, the reduction reaction mixture was filtered, the solid phase was collected, and the solid phase was washed with deionized water. The washed solid phase was vacuum dried at 100°C for 12 hours. The dried solid phase was ground to obtain 1g of carbon-based catalyst (particle diameter in the range of 1-3μm). The mass content of platinum in the carbon-based catalyst was determined to be 40.4%.

[0148] XPS analysis showed that the surface oxygen content of the carbon-based catalyst was 5.4 mol % based on the total amount of elements on the catalyst surface; 1s The total amount of O is based on the first characteristic peak. 1s The content of O is 4.3 mol%, which is determined by the second characteristic peak. 1s The content of O is 32.5 mol%, which is determined by the third characteristic peak. 1s The content is 63.2 mol%.

[0149] The electrochemical performance of the prepared carbon-based catalyst (first cycle) and the electrochemical performance after 5000 cycles were measured using a rotating disk test. The experimental results are listed in Table 1.

[0150] Figure 1 The XPS spectra of the carbon-based catalysts prepared in Example 1, Comparative Example 1 and Comparative Example 2 are shown in FIG. Figure 1It can be seen that the carbon-based catalyst prepared by the method of the present invention has a first characteristic peak at 536.2±0.2eV, however, the carbon-based catalysts prepared in Comparative Examples 1 and 2 do not have this characteristic peak. The first characteristic peak corresponds to the isolated CO molecules and / or CO2 molecules adsorbed on the carbon-based catalyst. The oxygen in the group, the isolated CO molecules and / or CO2 molecules present in the carbon-based catalyst have a certain influence on the electronic structure of platinum in the carbon-based catalyst, which helps to improve the activity and stability of the carbon-based catalyst.

[0151] It can be seen from the results in Table 1 that the carbon-based catalyst according to the present invention has not only high activity but also high stability. Figure 2 This is the ORR stability test curve of the carbon-based catalyst prepared in Example 1. Figure 2 It can be seen that the carbon-based catalyst according to the present invention maintains a relatively high ORR performance after 5000 cycles.

[0152] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

[0153]

[0154]

Claims

1. A carbon-based catalyst comprising a carbonaceous support and platinum element supported on the carbonaceous support, characterized in that: X-ray photoelectron spectroscopy of the carbon-based catalyst O 1s Among the peaks, there is a first characteristic peak at 536.2±0.2 eV, a second characteristic peak at 532±0.4 eV, and a third characteristic peak at 533.5±0.2 eV. The first characteristic peak corresponds to the isolated CO molecules and / or CO2 molecules adsorbed on the carbon-based catalyst. The peak of oxygen in the group is determined by X-ray photoelectron spectroscopy. 1s Based on the total amount of the carbon-based catalyst, the O 1s The content of is 3-5 mol %, based on the total molar amount of C determined by X-ray photoelectron spectroscopy, the surface oxygen content of the carbon-based catalyst is more than 5 mol %, and the surface oxygen content is determined by X-ray photoelectron spectroscopy.

2. The carbon-based catalyst according to claim 1, wherein O was determined by X-ray photoelectron spectroscopy 1s Based on the total amount of the carbon-based catalyst, the O 1s The content is 3.5-5 mol%.

3. The carbon-based catalyst according to claim 1 or 2, wherein O was determined by X-ray photoelectron spectroscopy 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s The molar ratio is 1.4-2.2:

1.

4. The carbon-based catalyst according to claim 1 or 2, wherein O was determined by X-ray photoelectron spectroscopy 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s The molar ratio is 1.6-2.1:

1.

5. The carbon-based catalyst according to claim 1 or 2, wherein O was determined by X-ray photoelectron spectroscopy 1s Based on the total amount of O in the carbon-based catalyst, the O 1s O determined by the third characteristic peak 1s The molar ratio is 1.7-2:

1.

6. The carbon-based catalyst according to claim 1 or 2, wherein The surface oxygen content of the carbon-based catalyst is 5-7 mol % based on the total molar amount of C determined by X-ray photoelectron spectroscopy.

7. The carbon-based catalyst according to claim 1 or 2, wherein The surface oxygen content of the carbon-based catalyst is 5.2-6.2 mol % based on the total molar amount of C determined by X-ray photoelectron spectroscopy.

8. The carbon-based catalyst according to claim 1 or 2, wherein Based on the total amount of the carbon-based catalyst, the content of the platinum element is 0.1-80% by weight, the content of the carbonaceous carrier is 20-99.9% by weight, and the carbonaceous carrier is calculated as carbon element.

9. The carbon-based catalyst according to claim 1 or 2, wherein Based on the total amount of the carbon-based catalyst, the content of the platinum element is 10-60% by weight, the content of the carbonaceous carrier is 40-90% by weight, and the carbonaceous carrier is calculated as carbon element.

10. The carbon-based catalyst according to claim 1 or 2, wherein Based on the total amount of the carbon-based catalyst, the content of the platinum element is 30-45% by weight, the content of the carbonaceous carrier is 55-70% by weight, and the carbonaceous carrier is calculated as carbon element.

11. The carbon-based catalyst according to claim 1 or 2, wherein The carbonaceous carrier is conductive carbon black.

12. The carbon-based catalyst according to claim 1 or 2, wherein The specific surface area of ​​the carbonaceous carrier is 200-2000m 2 / g.

13. The carbon-based catalyst according to claim 1 or 2, wherein The specific surface area of ​​the carbonaceous carrier is 250-1500m 2 / g.

14. A method for preparing a carbon-based catalyst, the method comprising the following steps: Step S1, soaking the carbon-based raw material in an organic solvent to obtain a first carbon-based material, wherein the organic solvent is a ketone solvent; Step S2, contacting the first carbon-based material with an oxidant to obtain a second carbon-based material, wherein the oxidant is one or more selected from peroxides; Step S3, contacting the second carbon-based material with nitric acid to obtain a third carbon-based material; Step S4, calcining the third carbon-based material in an inert atmosphere to obtain a carbonaceous support, wherein the calcination temperature is 800-1800° C.; Step S5, dispersing the carbonaceous support and the platinum precursor in an aqueous phase, adding a pH adjuster to the aqueous phase to adjust the pH value of the aqueous phase to alkaline, and obtaining an aqueous dispersion; Step S6: contacting the aqueous dispersion with a reducing agent to reduce at least a portion of the platinum precursor to metallic platinum, wherein the reducing agent is one or more of citric acid, ascorbic acid, and formic acid, and the molar ratio of the reducing agent to the platinum precursor is 4-1000:1, and the platinum precursor is calculated as platinum element.

15. The preparation method according to claim 14, wherein In step S1, the organic solvent is acetone.

16. The preparation method according to claim 14 or 15, wherein In step S1, the temperature of the organic solvent is 50-70° C., and the soaking time is 5-12 hours.

17. The preparation method according to claim 14, wherein In step S2, the oxidant is hydrogen peroxide.

18. The preparation method according to claim 14 or 17, wherein In step S2, the mass ratio of the oxidant to the first carbon-based material is 1-3:

1.

19. The preparation method according to claim 14 or 17, wherein In step S2, the contact temperature is 50-70°C, and the contact duration is 5-12 hours.

20. The preparation method according to claim 14, wherein In step S3, the mass ratio of nitric acid to the second carbon-based material is 1-3:1, and the nitric acid is calculated as HNO3.

21. The preparation method according to claim 14 or 20, wherein In step S3, the contact temperature is 50-70° C., and the contact duration is 5-12 hours.

22. The preparation method according to claim 14, wherein In step S4, the third carbon-based material is calcined at a temperature of 900-1600° C. in an inert atmosphere.

23. The preparation method according to claim 14, wherein In step S4, the third carbon-based material is calcined at a temperature of 1000-1500° C. in an inert atmosphere.

24. The preparation method according to claim 14, wherein In step S4, the third carbon-based material is calcined at a temperature of 1000-1200° C. in an inert atmosphere.

25. The preparation method according to any one of claims 14 and 22-24, wherein: In step S4, the roasting duration is 5-12 hours.

26. The preparation method according to claim 14, wherein In step S5, the concentration of the platinum precursor in the aqueous dispersion is 0.01-0.1 mol / L.

27. The preparation method according to claim 14, wherein In step S5, the concentration of the platinum precursor in the aqueous dispersion is 0.01-0.05 mol / L.

28. The preparation method according to any one of claims 14, 26 and 27, wherein: The platinum precursor is one or more selected from chloroplatinic acid, potassium chloroplatinate and sodium chloroplatinate.

29. The preparation method according to any one of claims 14, 26 and 27, wherein: In step S5, the amount of the platinum precursor used is such that in the finally prepared carbon-based catalyst, based on the total amount of the carbon-based catalyst, the content of the platinum element is 0.1-80% by weight, and the content of the carbonaceous carrier is 20-99.9% by weight, where the carbonaceous carrier is calculated as carbon element.

30. The preparation method according to any one of claims 14, 26 and 27, wherein: In step S5, the amount of the platinum precursor used is such that in the finally prepared carbon-based catalyst, based on the total amount of the carbon-based catalyst, the content of the platinum element is 10-60% by weight, and the content of the carbonaceous carrier is 40-90% by weight, where the carbonaceous carrier is calculated as carbon element.

31. The preparation method according to any one of claims 14, 26 and 27, wherein: In step S5, the amount of the platinum precursor used is such that in the finally prepared carbon-based catalyst, based on the total amount of the carbon-based catalyst, the content of the platinum element is 30-45% by weight, and the content of the carbonaceous carrier is 55-70% by weight, where the carbonaceous carrier is calculated as carbon element.

32. The preparation method according to claim 14, wherein In step S5, the pH value of the aqueous phase is adjusted to 8-14.

33. The preparation method according to claim 14, wherein In step S5, the pH value of the aqueous phase is adjusted to 10-13.

34. The preparation method according to any one of claims 14, 32 and 33, wherein: In step S5, the pH adjuster is one or more of sodium carbonate, potassium carbonate, potassium hydroxide and sodium hydroxide.

35. The preparation method according to claim 14, wherein In step S6, the reducing agent is formic acid.

36. The preparation method according to claim 14 or 35, wherein In step S6, the molar ratio of the reducing agent to the platinum precursor is 5-200:1, and the platinum precursor is calculated as platinum element.

37. The preparation method according to claim 14 or 35, wherein In step S6, the molar ratio of the reducing agent to the platinum precursor is 5-100:1, and the platinum precursor is calculated as platinum element.

38. The preparation method according to claim 14 or 35, wherein In step S6, the molar ratio of the reducing agent to the platinum precursor is 5-10:1, and the platinum precursor is calculated as platinum element.

39. The preparation method according to claim 14 or 35, wherein In step S6, the contacting is performed at a temperature of 50-150°C.

40. The preparation method according to claim 14 or 35, wherein In step S6, the contacting is performed at a temperature of 80-130°C.

41. The preparation method according to claim 14 or 35, wherein In step S6, the contacting is performed at a temperature of 90-120°C.

42. The preparation method according to claim 14 or 35, wherein In step S6, the contacting lasts for 4-12 hours.

43. A carbon-based catalyst prepared by the method of any one of claims 14 to 42.

44. Use of the carbon-based catalyst according to any one of claims 1 to 13 and 43 in a fuel cell.

45. A hydrogen fuel cell, the anode and / or cathode of which contains the carbon-based catalyst according to any one of claims 1 to 13 and 43.

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