Iridium-based catalyst as well as preparation method and application thereof

Abstract

The invention discloses an iridium-based catalyst as well as a preparation method and application thereof. The catalyst comprises an active component and a carrier, wherein the active component comprises iridium and at least one transition metal selected from iron, cobalt and nickel; the carrier is a nitrogen-doped carbon material. The catalyst provided by the invention has the advantages of large electrochemical activity surface area, high oxygen evolution reaction catalytic activity and good stability, and is suitable for oxygen evolution reaction under acidic conditions.

Description

Technical Field

[0001] The invention belongs to the field of electrocatalysis, and specifically relates to an iridium-based catalyst and a preparation method thereof, as well as application of the iridium-based catalyst in oxygen evolution reactions. Background Art

[0002] Hydrogen energy has attracted much attention as a clean and renewable energy source. Hydrogen production by water electrolysis is currently one of the most commonly used methods of hydrogen production. Hydrogen production by water electrolysis decomposes water molecules into hydrogen and oxygen. The oxygen evolution reaction occurring at the anode is an important component of hydrogen production by water electrolysis. In the oxygen evolution reaction, iridium catalyst is a commonly used catalyst, but the content of iridium in the earth's crust is extremely low, which limits the large-scale application of hydrogen production technology by water electrolysis. In order to further improve the efficiency of iridium catalysts and reduce the amount of precious metals used, alloying is a feasible method. Alloying can improve the stability and activity of the catalyst and reduce the amount of precious metals used to a certain extent.

[0003] At present, some achievements have been made in iridium-based alloy catalysts. CN110453256B discloses a polyhedral cobalt-iridium nanoparticle catalyst prepared by electrochemical deposition; CN112475314A discloses an iridium-based nanowire prepared by a mixed solvent chemical synthesis method, with a nanowire diameter of 20 to 100 nm. The above-disclosed catalysts all show better oxygen evolution reaction performance than iridium nanocatalysts. However, the above-mentioned synthesis process is generally not conducive to scale-up, and nanowires with large particle sizes and large cross-sections often have lower electrochemically active surface areas, and the catalyst performance needs to be improved. Summary of the invention

[0004] The purpose of the present invention is to provide an iridium-based catalyst and a preparation method and application thereof. The catalyst has the advantages of large electrochemical active surface area, high catalytic activity for oxygen evolution reaction and good stability, and is suitable for oxygen evolution reaction under acidic conditions.

[0005] The first aspect of the present invention provides an iridium-based catalyst, the catalyst comprising an active component and a carrier;

[0006] Wherein, the active component includes iridium and at least one transition metal selected from iron, cobalt and nickel; and the carrier is a nitrogen-doped carbon material.

[0007] Furthermore, the active component is twin nanowires.

[0008] Furthermore, the diameter d of the nanowire is 0.5-5 nm, and the size of the twin crystal grains constituting the nanowire is (0.8-1.1)·d nm.

[0009] Furthermore, the atomic ratio of iridium to transition metal in the active component is 1:(0.1-5), preferably 1:(0.2-3).

[0010] Furthermore, the nitrogen-doped carbon material is selected from at least one of nitrogen-doped carbon black, nitrogen-doped graphene, and nitrogen-doped carbon nanotubes.

[0011] Furthermore, the molar content of nitrogen in the nitrogen-doped carbon material is 0.5% to 5%.

[0012] Furthermore, the catalyst comprises, by weight, 10 to 95 parts of active components and 5 to 90 parts of nitrogen-doped carbon material carriers, preferably 20 to 90 parts of active components and 10 to 80 parts of nitrogen-doped carbon material carriers.

[0013] Furthermore, the electrochemical surface area of ​​the catalyst is 36 to 78 cm 2 , for example, it can be 40cm 2 、45cm 2 , 50cm 2 、55cm 2 、60cm 2 、65cm 2 、70cm 2 、75cm 2 The electrochemical surface area of ​​the catalyst is preferably 38 to 78 cm 2 .

[0014] The second aspect of the present invention provides a method for preparing the above-mentioned iridium-based catalyst, comprising the following steps:

[0015] (1) mixing an iridium source and a transition metal source, a surfactant, a crystal plane coordination agent, and an organic alcohol, and heating the mixture for reaction to obtain an iridium-based nanowire active component;

[0016] (2) The nitrogen-doped carbon material is mixed with the iridium-based nanowire active component, and then subjected to atmosphere heat treatment to obtain the iridium-based catalyst.

[0017] Furthermore, the iridium source in step (1) is selected from at least one of iridium chloride, iridium acetylacetonate, iridium carbonyl, hexachloroiridic acid, sodium hexachloroiridate, and ammonium hexachloroiridate.

[0018] Furthermore, the transition metal source in step (1) is selected from at least one of soluble chlorides, bromides, nitrates, sulfates, carbonates, acetates and acetylacetonates corresponding to transition metals iron, cobalt and nickel.

[0019] Furthermore, the surfactant in step (1) is polyvinyl pyrrolidone.

[0020] Furthermore, the crystal plane coordination agent in step (1) is a quaternary ammonium salt containing bromide ions and an inorganic iodide;

[0021] More preferably, the bromide-containing quaternary ammonium salt is selected from at least one of tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, hexadecyltrimethylammonium bromide and benzyltriethylammonium bromide;

[0022] More preferably, the inorganic iodide is selected from at least one of sodium iodide, potassium iodide and ammonium iodide.

[0023] Furthermore, the organic alcohol in step (1) is preferably a polyol, more preferably a diol and / or a triol; preferably, the polyol is selected from at least one of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, glycerol, diethylene glycol, and triethylene glycol.

[0024] Furthermore, the molar ratio of the iridium source, the transition metal source, and the crystal face coordination agent in step (1) is 1:(0.5-15):(5.1-32), preferably 1:(0.5-10):(5.1-32); preferably, the molar ratio of the iridium source, the crystal face coordination agent containing a quaternary ammonium salt of bromide ions, and the crystal face coordination agent inorganic iodide in step (1) is 1:(5-30):(0.1-1.2).

[0025] Furthermore, the mass ratio of the iridium source (based on iridium chloride hydrate), surfactant and organic alcohol in step (1) is 1:(8-12):(1500-1800).

[0026] Furthermore, the heating in step (1) is preferably carried out in a sealed state; optionally, a polyol solvent thermal reaction is carried out under heating conditions; optionally, the heating temperature is 130-230°C, preferably 160-190°C; the time is 4-60h, preferably 24-48h; the pressure is 0.8-1.5bar, preferably 0.8-1.2bar. Further, after the heating reaction in step (1), conventional post-treatment steps in the art (such as centrifugation, washing, and drying) can be used to obtain purified iridium-based nanowires. Among them, the centrifugation operation step is, for example, but not limited to, adding acetone to the product after the heating reaction and centrifuging; the washing and drying operation steps are, for example, but not limited to, ultrasonically dispersing the black precipitate after centrifugation with ethanol, adding acetone for centrifugal washing, repeating the above steps several times, and drying to obtain purified iridium-based nanowires.

[0027] Furthermore, the method for nitrogen doping the carbon carrier in step (2) is to dope the carbon carrier with nitrogen through a solid phase or liquid phase reaction, preferably a solid phase doping method. The specific steps of the solid phase doping method are to fully mix the carbon carrier and the nitrogen source powder, and heat them under oxidizing atmosphere conditions to obtain a nitrogen-doped carbon carrier powder. The mass ratio of the carbon carrier and the nitrogen source powder is 1:0.2 to 5.

[0028] Furthermore, the nitrogen source in the nitrogen doping can be selected from conventional nitrogen sources disclosed in the art, such as but not limited to at least one of urea, biuret, ammonium nitrate, ammonium bicarbonate, and melamine.

[0029] Furthermore, the carbon carrier in the nitrogen-doped carbon material is at least one of carbon black, graphene, carbon nanotubes, and activated carbon. Optionally, the carbon carrier may be pre-treated by oxidation.

[0030] Furthermore, the nitrogen doping atmosphere is an oxygen atmosphere with an oxygen content of 5 vol% to 20 vol%, and in the oxidizing atmosphere, except for oxygen, the remaining is nitrogen or / and at least one of an inert gas, wherein the inert gas is selected from at least one of argon and helium. The heating temperature is 150 to 350° C., preferably 200 to 350° C., and the time is 0.5 to 6 hours, preferably 0.5 to 4 hours.

[0031] Furthermore, in step (2), a dispersion containing the iridium-based nanowire metal active component of step (1) is first prepared, and then mixed with the nitrogen-doped carbon carrier. Optionally, after mixing, solid powder is obtained by ultrasonication, centrifugation, and drying.

[0032] Furthermore, the dispersion in step (2) is ethanol and / or isopropanol containing metal active components of iridium-based nanowires, and the mass fraction of the metal active components in the dispersion is 0.2% to 2%.

[0033] Furthermore, in step (2), the mass ratio of the iridium-based nanowire active component to the nitrogen-doped carbon carrier is 10-95:5-90, preferably 20-90:10-80.

[0034] Furthermore, in step (2), the ultrasonic treatment time is 8 to 24 hours; the drying temperature is 60 to 120° C., and the drying time is 4 to 12 hours.

[0035] Furthermore, the atmosphere heat treatment in step (2) is a treatment in an oxidizing atmosphere at 200 to 350° C. for 0.5 to 4 hours.

[0036] Furthermore, the oxygen content in the oxidizing atmosphere in step (2) is 5 vol% to 20 vol%.

[0037] Furthermore, in the oxidizing atmosphere in step (2), except for oxygen, the remaining is nitrogen and / or at least one of an inert gas, wherein the inert gas is selected from at least one of argon and helium.

[0038] The third aspect of the present invention is the use of the above catalyst in oxygen evolution reaction under acidic conditions.

[0039] Furthermore, the oxygen evolution reaction under acidic conditions may be an anode oxygen evolution reaction of water electrolysis or carbon dioxide electroreduction under acidic conditions.

[0040] Furthermore, the acidic oxygen evolution reaction includes oxygen evolution reactions occurring on the surface of the polymer electrolyte membrane and in the acidic solution.

[0041] Furthermore, the polymer electrolyte membrane includes at least one of a perfluorosulfonic acid proton membrane, a partially fluorinated polymer proton membrane, a non-fluorinated polymer proton membrane, and a composite membrane.

[0042] Furthermore, the acidic solution is selected from at least one of perchloric acid and sulfuric acid, and the concentration of the acidic solution is 0.01 to 2 mol / L.

[0043] Furthermore, the acidic solution is an oxygen-saturated acidic solution at 20-80°C.

[0044] The present invention has the following beneficial effects:

[0045] In the iridium-based catalyst of the present invention, the active component is a twin nanowire with a large electrochemical surface area. This active component can not only significantly reduce the amount of precious metal iridium, but also has excellent catalytic activity and stability for oxygen evolution reaction. At the same time, the preparation method provided by the present invention is simple, has little impact on the environment, and the prepared iridium-based catalyst has uniform size and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a high-resolution TEM image of the iridium-based nanowires, the active component of Example 1;

[0047] Figure 2 This is the TEM image of the active component iridium-based nanocrystals in comparative example 3. DETAILED DESCRIPTION

[0048] The following examples will further illustrate the technical solutions provided by the present invention, but the protection scope of the present invention is not limited by these examples.

[0049] In the following examples, the oxygen saturation at 25°C was 0.5 mol·L -1 In sulfuric acid solution, a three-electrode system was tested using an Ag / AgCl electrode as a reference electrode, a platinum electrode as a counter electrode, and a rotating disk electrode at a speed of 1600 rpm as a working electrode. The catalyst and perfluorosulfonic acid polymer Nafion solution were dispersed in water / ethanol / isopropanol, and ultrasonic dispersion was performed to obtain a catalyst slurry. The catalyst slurry was dropped on the surface of the rotating disk electrode and dried to obtain a thin film electrode. The oxygen evolution reaction current at a reaction overpotential of 0.25 V was used as a reference to compare the oxygen evolution reaction activity of the catalyst. The catalyst was tested at a reaction overpotential of 10 mA cm-2 The stable operation time at a current density of 1.547 W was used as the evaluation criterion for the catalyst stability.

[0050] In the present invention, the diameter of the nanowire is measured by a transmission electron microscope (TEM) photograph, with a TEM acceleration voltage of 200 to 300 kV and a magnification of 200 to 1500 k×. The length perpendicular to the axial direction of the nanowire in the TEM photograph is measured using Nano Measurer software, and 200 measurement results at different positions are counted to calculate the average value and standard deviation to obtain the diameter of the nanowire.

[0051] Example 1

[0052] Add 2.5g polyvinylpyrrolidone (PVP), 1mmol iridium chloride hydrate and 2mmol cobalt chloride hexahydrate to 475g ethylene glycol, stir until completely dissolved, then add 12mmol tetraethylammonium bromide and 0.5mmol potassium iodide, stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle, react at 190°C and 1bar for 48h, add acetone to the product and centrifuge it to obtain a black precipitate, disperse it with ethanol ultrasonically, add acetone to wash it by centrifugation, repeat the above steps several times, and dry it to obtain purified iridium cobalt nanowires. The ratio of iridium atoms to cobalt atoms is 1:0.6. The TEM image of the iridium cobalt nanowire is shown in Figure 1 ,pass Figure 1 It can be seen that the size distribution of the nanowires is narrow and presents a twin structure. The diameter d of the nanowires is 3.5±0.3nm, and the size of the twin crystal grains that make up the nanowires is 3.4nm.

[0053] The step of nitrogen-doping graphene is to fully grind and mix 1g of graphene oxide and 4g of urea, heat at 250°C for 2h in an oxidizing atmosphere containing 10vol% oxygen and 90vol% helium, and cool to obtain nitrogen-doped graphene powder.

[0054] 46 mg of iridium cobalt nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 12 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 250°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 2.5 h to obtain an iridium cobalt nanowire catalyst.

[0055] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​54.4 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 113.0μA / cm2 , at 10 mA cm -2 The system can run stably for 32h at a current density of .

[0056] Example 2

[0057] Add 3.5g polyvinylpyrrolidone (PVP), 1mmol iridium acetylacetonate and 4mmol ferrous sulfate heptahydrate to 500g ethylene glycol, stir until completely dissolved, then add 5mmol tetramethylammonium bromide and 0.3mmol sodium iodide, stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle and react at 180°C and 0.8bar for 36h. Add acetone to the product and centrifuge it to obtain a black precipitate. Ultrasonic dispersion with ethanol is obtained, and acetone is added for centrifugal washing. Repeat the above steps several times and dry to obtain purified iridium iron nanowires. The ratio of iridium atoms to iron atoms is 1:1.2. The TEM image of the iridium iron nanowires is similar to Figure 1 It is similar to the nanowires, and the size distribution is narrow, showing a twin structure. The diameter d of the nanowire is 3.7±0.3nm, and the size of the twin crystal grains constituting the nanowire is 3.5nm.

[0058] The steps of nitrogen-doping graphene are as follows: 1 g of graphene oxide and 3 g of melamine are fully ground and mixed, heated at 350° C. for 4 h in an oxidizing atmosphere containing 20 vol% oxygen and 80 vol% helium, and cooled to obtain nitrogen-doped graphene powder.

[0059] 57 mg of iridium iron nanowires were dispersed in 50 mL of isopropanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 10 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 70°C for 6 h to obtain a black solid powder. The solid powder was treated at 250°C in an oxidizing atmosphere containing 15 vol% oxygen and 85 vol% nitrogen for 1.5 h to obtain an iridium iron nanowire catalyst.

[0060] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​51.4 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 125.4μA / cm 2 , at 10 mA cm -2 The system can run stably for 25 h at a current density of 1.5 %.

[0061] Example 3

[0062] Add 3g of polyvinylpyrrolidone (PVP), 0.25mmol of tetrairidium dodecacarbonyl and 0.5mmol of hydrated nickel bromide to 525g of glycerol, stir until completely dissolved, then add 8mmol of tetraethylammonium bromide and 0.1mmol of ammonium iodide, and stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle and react at 170°C and 0.9bar for 30h. Add acetone to the obtained product and centrifuge it to obtain a black precipitate. Disperse it with ethanol ultrasonically, add acetone and centrifuge it for washing. Repeat the above steps several times and dry it to obtain purified iridium nickel nanowires. The ratio of iridium atoms to nickel atoms is 1:0.2. The TEM image of the iridium nickel nanowires is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 1.4±0.2nm, and the size of the twin crystal grains that make up the nanowires is 1.2nm.

[0063] The steps of nitrogen-doping carbon nanotubes are as follows: 1g of oxidized carbon nanotubes and 2g of ammonium bicarbonate are fully ground and mixed, heated at 320°C for 3h in an oxidizing atmosphere containing 20vol% oxygen and 80vol% helium, and cooled to obtain nitrogen-doped carbon nanotube powder.

[0064] 21 mg of iridium nickel nanowires were dispersed in 50 mL of isopropanol, 85 mg of nitrogen-doped carbon nanotubes were added, and the mixture was ultrasonically treated for 20 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 120°C for 12 h to obtain a black solid powder. The solid powder was treated at 240°C in an oxidizing atmosphere containing 20 vol% oxygen and 80 vol% argon for 2 h to obtain an iridium nickel nanowire catalyst.

[0065] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​67.1 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 97.1μA / cm 2 , at 10 mA cm -2 The system can run stably for 29h at a current density of .

[0066] Example 4

[0067] Add 3g polyvinylpyrrolidone (PVP), 1mmol iridium acetylacetonate and 1mmol basic nickel carbonate to 550g glycerol, stir until completely dissolved, then add 15mmol tetrabutylammonium bromide and 0.7mmol potassium iodide, stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle and react at 160°C and 1.1bar for 24h. Add acetone to the product and centrifuge it to obtain a black precipitate. Disperse it with ethanol ultrasonically, add acetone and centrifuge it for washing. Repeat the above steps several times and dry it to obtain purified iridium nickel nanowires. The ratio of iridium atoms to nickel atoms is 1:0.3. The TEM image of the iridium nickel nanowires is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 2.2±0.2nm, and the size of the twin crystal grains that make up the nanowires is 2.2nm.

[0068] The steps of nitrogen-doping carbon black are as follows: 1 g of carbon black and 1 g of biuret are fully ground and mixed, heated at 300° C. for 2 h in an oxidizing atmosphere containing 15 vol % oxygen and 85 vol % helium, and cooled to obtain nitrogen-doped carbon black powder.

[0069] 26 mg of iridium nickel nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped carbon black was added, and the mixture was ultrasonically treated for 15 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 100°C for 10 h to obtain a black solid powder. The solid powder was treated at 300°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% argon for 4 h to obtain an iridium nickel nanowire catalyst.

[0070] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​60.5 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 102.9μA / cm 2 , at 10 mA cm -2 The system can run stably for 37h at a current density of .

[0071] Example 5

[0072] Add 3.8g polyvinyl pyrrolidone (PVP), 1mmol hydrated iridium chloride and 10mmol acetylacetonate iron to 560g 1,2-propylene glycol, stir until completely dissolved, then add 20mmol tetramethylammonium bromide and 0.9mmol sodium iodide, stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle and react at 170°C and 1bar for 36h. Add acetone to the product and centrifuge it to obtain a black precipitate. Disperse it with ethanol ultrasonically, add acetone and centrifuge it for washing. Repeat the above steps several times and dry it to obtain purified iridium iron nanowires. The ratio of iridium atoms to iron atoms is 1:3. The TEM image of the iridium iron nanowires is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 4.6±0.5nm, and the size of the twin crystal grains that make up the nanowires is 4.9nm.

[0073] The steps of nitrogen-doping carbon black are as follows: 1 g of carbon black and 0.5 g of biuret are fully ground and mixed, heated at 200° C. for 0.5 h in an oxidizing atmosphere containing 5 vol % oxygen and 95 vol % helium, and cooled to obtain nitrogen-doped carbon black powder.

[0074] 340 mg of iridium iron nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped carbon black was added, and the mixture was ultrasonically treated for 18 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 110°C for 10 h to obtain a black solid powder. The solid powder was treated at a temperature of 270°C in an oxidizing atmosphere containing 15 vol% oxygen and 85 vol% helium for 3 h to obtain an iridium iron nanowire catalyst.

[0075] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​42.7 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 109.6μA / cm 2 , at 10 mA cm -2 The system ran stably for 41 h at a current density of .

[0076] Example 6

[0077] Add 2.75g polyvinylpyrrolidone (PVP), 1mmol iridium acetylacetonate and 3mmol octacarbonyl dicobalt to 570g 1,2-propylene glycol, stir until completely dissolved, then add 30mmol tetrabutylammonium bromide and 1.1mmol ammonium iodide, stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle and react at 180°C and 1bar for 30h. Add acetone to the product and centrifuge it to obtain a black precipitate. Disperse it with ethanol ultrasonically, add acetone and centrifuge it for washing. Repeat the above steps several times and dry it to obtain purified iridium cobalt nanowires. The ratio of iridium atoms to cobalt atoms is 1:2. The TEM image of the iridium cobalt nanowires is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 4.1±0.4nm, and the size of the twin crystal grains that make up the nanowires is 4.5nm.

[0078] The steps of nitrogen-doping carbon nanotubes are as follows: 1 g of carbon black and 2.5 g of urea are fully ground and mixed, heated at 270° C. for 1 h in an oxidizing atmosphere containing 15 vol % oxygen and 85 vol % helium, and cooled to obtain nitrogen-doped carbon nanotubes.

[0079] 128 mg of iridium cobalt nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped carbon nanotubes were added, and ultrasonic treatment was performed for 22 h. The black precipitate was obtained by centrifugation, and dried in an oven at 60 ° C for 4 h to obtain a black solid powder. The solid powder was treated at a temperature of 210 ° C in an oxidizing atmosphere containing 20 vol% oxygen and 80 vol% nitrogen for 3.5 h to obtain an iridium cobalt nanowire catalyst.

[0080] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​48.3 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 108.3μA / cm 2 , at 10 mA cm -2 The system can run stably for 44 hours at a current density of .

[0081] Example 7

[0082] Add 2.75g polyvinylpyrrolidone (PVP), 0.25mmol tetrairidium dodecacarbonyl and 8mmol nickel chloride hexahydrate to 480g ethylene glycol, stir until completely dissolved, then add 24mmol hexadecyltrimethylammonium bromide and 1.2mmol potassium iodide, stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle, react at 160°C and 1.2bar for 48h, dry the obtained product, add acetone and centrifuge to obtain a black precipitate, disperse it with ethanol ultrasonically, add acetone and centrifuge for washing, repeat the above steps several times to obtain purified iridium nickel nanowires. The ratio of iridium atoms to nickel atoms is 1:2.5. The TEM image of the iridium nickel nanowire is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 4.3±0.5nm, and the size of the twin crystal grains that make up the nanowires is 4.7nm.

[0083] The steps of nitrogen-doping carbon nanotubes are as follows: 1 g of oxidized carbon nanotubes and 0.2 g of urea are fully ground and mixed, heated at 240° C. for 1.5 h in an oxidizing atmosphere containing 5 vol % oxygen and 95 vol % helium, and cooled to obtain nitrogen-doped carbon nanotubes.

[0084] 198 mg of iridium nickel nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped carbon nanotubes were added, and the mixture was ultrasonically treated for 24 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 90°C for 12 h to obtain a black solid powder. The solid powder was treated at 200°C in an oxidizing atmosphere containing 20 vol% oxygen and 80 vol% nitrogen for 1 h to obtain an iridium nickel nanowire catalyst.

[0085] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​46.0 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 87.5μA / cm 2 , at 10 mA cm -2 The system can run stably for 42h at a current density of .

[0086] Example 8

[0087] Add 3.5g polyvinylpyrrolidone (PVP), 1mmol hydrated iridium chloride and 5mmol cobalt acetate to 500g glycerol, stir until completely dissolved, then add 26mmol hexadecyltrimethylammonium bromide and 0.5mmol sodium iodide, stir for 0.5h to obtain a clear solution. Add it to an 800mL hydrothermal kettle and react at 190°C and 1.5bar for 24h. Add acetone to the obtained product and centrifuge it to obtain a black precipitate. Disperse it with ethanol ultrasonically, add acetone and centrifuge it for washing. Repeat the above steps several times and dry it to obtain purified iridium cobalt nanowires. The ratio of iridium atoms to cobalt atoms is 1:1.5. The TEM image of the iridium cobalt nanowires is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 3.9±0.4nm, and the size of the twin crystal grains that make up the nanowires is 3.7nm.

[0088] The steps of nitrogen-doping graphene are as follows: 1 g of graphene oxide and 5 g of melamine are fully ground and mixed, heated at 220° C. for 3 h in an oxidizing atmosphere containing 5 vol% oxygen and 95 vol% helium, and cooled to obtain nitrogen-doped graphene.

[0089] 85 mg of iridium cobalt nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 8 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 280°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 3 h to obtain an iridium cobalt nanowire catalyst.

[0090] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​49.8 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 116.5μA / cm 2 , at 10 mA cm -2 The system can run stably for 42h at a current density of .

[0091] Example 9

[0092] Add 2.5g polyvinylpyrrolidone (PVP), 1mmol hydrated iridium chloride and 0.3mmol cobalt chloride hexahydrate to 475g ethylene glycol, stir until completely dissolved, then add 12mmol tetraethylammonium bromide and 0.5mmol potassium iodide, stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle, react at 190°C and 1bar for 48h, add acetone to the product and centrifuge it to obtain a black precipitate, disperse it with ethanol ultrasonically, add acetone to wash it by centrifugation, repeat the above steps several times, and dry it to obtain purified iridium cobalt nanowires. The ratio of iridium atoms to cobalt atoms is 1:0.1. The TEM image of the iridium cobalt nanowires is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 0.5±0.1nm, and the size of the twin crystal grains that make up the nanowires is 0.4nm.

[0093] The step of nitrogen-doping graphene is to fully grind and mix 1g of graphene oxide and 4g of urea, heat at 250°C for 2h in an oxidizing atmosphere containing 10vol% oxygen and 90vol% helium, and cool to obtain nitrogen-doped graphene powder.

[0094] 9.5 mg of iridium cobalt nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 12 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 250°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 2.5 h to obtain an iridium cobalt nanowire catalyst.

[0095] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​77.9 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 71.7μA / cm 2 , at 10 mA cm -2 The system can run stably for 35h at a current density of 1.58kV.

[0096] Example 10

[0097] Add 2.5g polyvinylpyrrolidone (PVP), 1mmol iridium chloride hydrate and 15mmol cobalt chloride hexahydrate to 475g ethylene glycol, stir until completely dissolved, then add 12mmol tetraethylammonium bromide and 0.5mmol potassium iodide, stir for 0.5h to obtain a clear solution. Add it to an 800mL hydrothermal kettle and react at 190°C and 1bar for 48h. Add acetone to the obtained product and centrifuge it to obtain a black precipitate. Ultrasonic dispersion with ethanol is obtained, and acetone is added for centrifugal washing. Repeat the above steps several times and dry to obtain purified iridium cobalt nanowires. The ratio of iridium atoms to cobalt atoms is 1:5. The TEM image of the iridium cobalt nanowires is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 5.0±0.7nm, and the size of the twin crystal grains that make up the nanowires is 4.4nm.

[0098] The step of nitrogen-doping graphene is to fully grind and mix 1g of graphene oxide and 4g of urea, heat at 250°C for 2h in an oxidizing atmosphere containing 10vol% oxygen and 90vol% helium, and cool to obtain nitrogen-doped graphene powder.

[0099] 1.6 g of iridium cobalt nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 12 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 250°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 2.5 h to obtain an iridium cobalt nanowire catalyst.

[0100] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​36.2 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 57.2μA / cm 2 , at 10 mA cm -2 The system can run stably for 27h at a current density of .

[0101] Comparative Example 1

[0102] Commercial iridium carbon catalyst with a loading of 40% was saturated with 0.5 mol·L oxygen at 25°C. -1 In sulfuric acid solution, using a three-electrode system at a reaction overpotential of 0.25 V, the electrochemically active surface area of ​​the catalyst was 28.6 cm 2 , catalyst specific activity 36.6μA / cm 2 , at 10 mA cm -2 The system can run stably for 13 h at a current density of .

[0103] Comparative Example 2

[0104] Add 2.5g polyvinyl pyrrolidone (PVP), 1mmol hydrated iridium chloride and 2mmol hexahydrated cobalt chloride to 475g ethylene glycol, stir until completely dissolved, then add 0.5mmol potassium iodide and stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle and react at 190°C and 1bar for 48h. Add acetone to the obtained product and centrifuge it to obtain a black precipitate. Ultrasonic dispersion with ethanol is obtained, and acetone is added for centrifugal washing. Repeat the above steps several times and dry to obtain purified iridium cobalt nanowires. The ratio of iridium atoms to cobalt atoms is 1:0.6. The TEM image of the iridium cobalt nanowire is similar to Figure 1 It is similar to the nanowires, and the size distribution is narrow, showing a twin structure. The nanowire diameter d is 4.9±0.6nm, and the twin grain size of the nanowire is 4.1nm.

[0105] The step of nitrogen-doping graphene is to fully grind and mix 1g of graphene oxide and 4g of urea, heat at 250°C for 2h in an oxidizing atmosphere containing 10vol% oxygen and 90vol% helium, and cool to obtain nitrogen-doped graphene powder.

[0106] 46 mg of iridium cobalt nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 12 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 250°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 2.5 h to obtain an iridium cobalt nanowire catalyst.

[0107] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​37.7 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 74.9μA / cm 2 , at 10 mA cm -2 The system can run stably for 16 h at a current density of .

[0108] Comparative Example 3

[0109] Add 2.5g polyvinylpyrrolidone (PVP), 1mmol iridium chloride hydrate and 2mmol cobalt chloride hexahydrate to 475g ethylene glycol, stir until completely dissolved, then add 12mmol tetraethylammonium bromide and stir for 0.5h to obtain a clear solution. Add it to a 800mL hydrothermal kettle and react at 190°C and 1bar for 48h. Add acetone to the product and centrifuge it to obtain a black precipitate. Disperse it with ethanol ultrasonically, add acetone and centrifuge it for washing. Repeat the above steps several times and dry it to obtain purified iridium cobalt nanocrystals. The ratio of iridium atoms to cobalt atoms is 1:0.6. The TEM image of the iridium cobalt nanocrystals is as follows Figure 2 As shown in Figure 2, the nanocrystal diameter d is 3.5±0.2nm.

[0110] The step of nitrogen-doping graphene is to fully grind and mix 1g of graphene oxide and 4g of urea, heat at 250°C for 2h in an oxidizing atmosphere containing 10vol% oxygen and 90vol% helium, and cool to obtain nitrogen-doped graphene powder.

[0111] 46 mg of iridium cobalt nanocrystals were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 12 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 250°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 2.5 h to obtain an iridium cobalt nanocrystal catalyst.

[0112] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​53.5 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 47.8μA / cm 2 , at 10 mA cm -2 The system can run stably for 27h at a current density of .

[0113] Comparative Example 4

[0114] Add 1mmol of iridium chloride hydrate and 2mmol of cobalt chloride hexahydrate to 475g of ethylene glycol, stir until completely dissolved, then add 12mmol of tetraethylammonium bromide and 0.5mmol of potassium iodide, stir for 0.5h to obtain a clear solution. Add it to an 800mL hydrothermal kettle, react at 190℃ and 1bar for 48h, add acetone to the product and centrifuge to obtain a black precipitate, disperse it with ethanol ultrasonically, add acetone to wash by centrifugation, repeat the above steps several times, and dry to obtain purified iridium cobalt nanocrystals. The ratio of iridium atoms to cobalt atoms is 1:0.3. The diameter d of iridium cobalt nanocrystals is 243±57nm.

[0115] The step of nitrogen-doping graphene is to fully grind and mix 1g of graphene oxide and 4g of urea, heat at 250°C for 2h in an oxidizing atmosphere containing 10vol% oxygen and 90vol% helium, and cool to obtain nitrogen-doped graphene powder.

[0116] 46 mg of iridium cobalt nanocrystals were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 12 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 250°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 2.5 h to obtain an iridium cobalt nanocrystal catalyst.

[0117] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​5.9 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 12.5μA / cm 2 , at 10 mA cm -2 The system can run stably for 12 h at a current density of .

[0118] Comparative Example 5

[0119] 2.5g polyvinyl pyrrolidone (PVP) and 1mmol hydrated iridium chloride were added to 475g ethylene glycol, stirred until completely dissolved, and then 12mmol tetraethylammonium bromide and 0.5mmol potassium iodide were added, and stirred for 0.5h to obtain a clear solution. It was added to an 800mL hydrothermal kettle and reacted at 190°C and 1bar for 48h. The obtained product was added with acetone and centrifuged to obtain a black precipitate. It was ultrasonically dispersed with ethanol, and acetone was added for centrifugation and washing. The above steps were repeated several times and dried to obtain purified iridium nanowires. The TEM image of the iridium nanowires is similar to that of the iridium nanowires. Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 2.7±0.3nm, and the size of the twin crystal grains that make up the nanowires is 2.6nm.

[0120] The step of nitrogen-doping graphene is to fully grind and mix 1g of graphene oxide and 4g of urea, heat at 250°C for 2h in an oxidizing atmosphere containing 10vol% oxygen and 90vol% helium, and cool to obtain nitrogen-doped graphene powder.

[0121] 46 mg of iridium nanowires were dispersed in 50 mL of ethanol, 85 mg of nitrogen-doped graphene was added, and the mixture was ultrasonically treated for 12 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 250°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 2.5 h to obtain an iridium nanowire catalyst.

[0122] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​58.3 cm at a reaction overpotential of 0.25 V. 2 , catalyst specific activity 45.1μA / cm 2 , at 10 mA cm -2 The system can run stably for 22h at a current density of .

[0123] Comparative Example 6

[0124] Add 2.5g polyvinylpyrrolidone (PVP), 1mmol iridium chloride hydrate and 2mmol cobalt chloride hexahydrate to 475g ethylene glycol, stir until completely dissolved, then add 12mmol tetraethylammonium bromide and 0.5mmol potassium iodide, stir for 0.5h to obtain a clear solution. Add it to an 800mL hydrothermal kettle and react at 190°C and 1bar for 48h. Add acetone to the obtained product and centrifuge it to obtain a black precipitate. Ultrasonic dispersion with ethanol is obtained, and acetone is added for centrifugal washing. Repeat the above steps several times and dry to obtain purified iridium cobalt nanowires. The ratio of iridium atoms to cobalt atoms is 1:0.6. The TEM image of the iridium cobalt nanowires is similar to Figure 1 It is similar to the above, and it can be seen that the size distribution of the nanowires is narrow, showing a twin structure. The diameter d of the nanowires is 3.5±0.3nm, and the size of the twin crystal grains that make up the nanowires is 3.4nm.

[0125] 46 mg of iridium cobalt nanowires were dispersed in 50 mL of ethanol, 85 mg of graphene was added, and the mixture was ultrasonically treated for 12 h. The mixture was centrifuged to obtain a black precipitate, which was dried in an oven at 80°C for 8 h to obtain a black solid powder. The solid powder was treated at a temperature of 250°C in an oxidizing atmosphere containing 10 vol% oxygen and 90 vol% helium for 2.5 h to obtain an iridium cobalt nanowire catalyst.

[0126] At 25℃, oxygen saturation is 0.5 mol·L -1 In sulfuric acid solution, the three-electrode system using Ag / AgCl electrode as reference electrode, platinum electrode as counter electrode, and rotating disk electrode with a rotation speed of 1600 rpm as working electrode has an electrochemical active surface area of ​​53.6 cm at a reaction overpotential of 0.25 V. 2, catalyst specific activity 48.4μA / cm 2 , at 10 mA cm -2 The system can run stably for 18 h at a current density of .

[0127] Table 1 Physicochemical properties and catalytic performance of various examples and comparative examples

[0128]

[0129] The embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. An iridium-based catalyst comprising an active component and a carrier; in, The active component comprises iridium and at least one transition metal selected from iron, cobalt and nickel; and the carrier is a nitrogen-doped carbon material.

2. The iridium-based catalyst according to claim 1, characterized in that The active component is a twinned nanowire; optionally, the diameter d of the nanowire is 0.5-5 nm, and the size of the twinned crystal grains constituting the nanowire is (0.8-1.1)·d nm.

3. The iridium-based catalyst according to claim 1, characterized in that In parts by weight, the catalyst comprises 10 to 95 parts of active components and 5 to 90 parts of nitrogen-doped carbon material carriers; optionally, the atomic ratio of iridium to transition metal in the active components is 1:(0.1 to 5).

4. The iridium-based catalyst according to claim 1, characterized in that The nitrogen-doped carbon material is selected from at least one of nitrogen-doped carbon black, nitrogen-doped graphene, and nitrogen-doped carbon nanotubes; optionally, the molar content of nitrogen in the nitrogen-doped carbon material is 0.5% to 5%.

5. The iridium-based catalyst according to claim 1, characterized in that The electrochemical surface area of ​​the catalyst is 36 to 78 cm 2 .

6. The method for preparing the iridium-based catalyst according to any one of claims 1 to 5, comprising the following steps: (1) mixing an iridium source and a transition metal source, a surfactant, a crystal plane coordination agent, and an organic alcohol, and heating the mixture for reaction to obtain an iridium-based nanowire active component; (2) The nitrogen-doped carbon material is mixed with the iridium-based nanowire active component, and then subjected to atmosphere heat treatment to obtain the iridium-based catalyst.

7. The preparation method according to claim 6, characterized in that: The iridium source in step (1) is selected from at least one of iridium chloride, iridium acetylacetonate, iridium carbonyl, hexachloroiridic acid, sodium hexachloroiridate, and ammonium hexachloroiridate; optionally, the transition metal source in step (1) is selected from at least one of soluble chlorides, bromides, nitrates, sulfates, carbonates, acetates, and acetylacetonates corresponding to transition metals iron, cobalt, and nickel.

8. The preparation method according to claim 6, characterized in that: The surfactant in step (1) is polyvinyl pyrrolidone; optionally, the crystal plane coordination agent in step (1) is a quaternary ammonium salt containing bromide ions and an inorganic iodide; optionally, the organic alcohol in step (1) is preferably a polyol.

9. The preparation method according to claim 6, characterized in that: The molar ratio of the iridium source, the transition metal source and the crystal plane coordination agent in step (1) is 1:(0.5-15):(5.1-32), preferably 1:(0.5-10):(5.1-32).

10. The preparation method according to claim 8, characterized in that: The molar ratio of the iridium source, the quaternary ammonium salt containing bromide ions as the crystal face coordination agent and the inorganic iodide as the crystal face coordination agent in step (1) is 1:(5-30):(0.1-1.2).

11. The preparation method according to claim 6, characterized in that: The iridium source in step (1) is based on hydrated iridium chloride and the mass ratio of the surfactant to the organic alcohol is 1:(8-12):(1500-1800).

12. The preparation method according to claim 6, characterized in that: The heating temperature in step (1) is 130-230° C., the heating time is 4-60 hours, and the heating pressure is 0.8-1.5 bar.

13. The preparation method according to claim 6, characterized in that: The carbon carrier in the nitrogen-doped carbon material in step (2) is at least one of carbon black, graphene, carbon nanotubes, and activated carbon; optionally; the mass ratio of the iridium-based nanowire active component to the nitrogen-doped carbon carrier in step (2) is 10-95:5-90.

14. The preparation method according to claim 6, characterized in that: The atmosphere heat treatment in step (2) is a treatment in an oxidizing atmosphere at 200 to 350° C. for 0.5 to 4 hours; optionally, the oxygen content in the oxidizing atmosphere in step (2) is 5 vol% to 20 vol% oxygen.

15. Use of the iridium-based catalyst according to any one of claims 1 to 6 in an oxygen evolution reaction under acidic conditions.

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