Graphene composite iridium-based ternary alloy pem electrolysis water catalyst and preparation method thereof

Abstract

The application discloses a graphene composite iridium-based ternary alloy PEM water electrolysis catalyst and a preparation method thereof, relates to the technical field of electrocatalysts, and the catalyst is a ternary metal composite graphene electrocatalyst; the base of the catalyst is a graphene layer; and noble metal iridium and transition metals molybdenum and cobalt are uniformly dispersed on the base. Graphene is an excellent conductive material; taking the graphene as the base can promote the activity of the catalyst, reduce the content of noble metal, and reduce the cost; and the addition of the transition metals molybdenum and cobalt further increases the activity among the multiple metals, and the performance of the catalyst can be further improved. The catalyst preparation method disclosed by the application significantly improves the activity and stability of OER (oxygen evolution reaction), greatly reduces the production cost, and has excellent industrialization feasibility. The technology effectively overcomes the limitations of the existing proton exchange membrane water electrolysis hydrogen production technology, and provides a breakthrough solution for the field of electrochemical energy storage and hydrogen energy engineering application.

Description

Technical Field

[0001] This invention relates to the field of electrocatalyst technology, and in particular to a graphene-iridium-based ternary alloy PEM water electrolysis catalyst and its preparation method. Background Technology

[0002] Hydrogen energy plays a crucial role in the future energy framework. Large-scale production largely depends on advancements in green hydrogen production technologies, with water electrolysis being a key pathway. In recent years, PEM (Potential Electrolysis Membrane Electrolysis) technology for hydrogen production has developed rapidly, becoming one of the most promising methods due to its superior characteristics, such as high current density, rapid response, excellent system integration, and high-purity hydrogen output. However, its development is severely limited in practical applications due to its high cost and insufficient stability under harsh operating conditions (including strong acid environments and high applied potentials). The membrane electrode catalyst primarily uses noble metals such as platinum and iridium; if other non-noble metals are used, they generally cannot operate stably for extended periods in strong acid environments. Therefore, developing inexpensive, efficient, and stable low-noble metal electrode materials is crucial for the large-scale application of PEM water electrolysis for hydrogen production.

[0003] Recent studies have shown that the most feasible strategy is to reduce the loading of precious metals while improving intrinsic catalytic activity and long-term stability through nanostructure modulation and conductive substrate optimization. The nanostructure of catalysts can be modulated by doping with inexpensive transition metals. This approach not only reduces the content of precious metals, thus lowering costs, but also improves electrocatalytic activity because different metals often exhibit synergistic effects, increasing the active surface area of ​​the catalyst. Conductive substrate optimization can be achieved through composite catalysts using carbon-based materials (such as carbon nanotubes, graphene, and activated carbon). Carbon-based materials possess excellent electrical conductivity, high specific surface area, outstanding electrochemical and chemical stability, and structural tunability, making them a key approach in the search for inexpensive, efficient, and stable PEM (polyethylene glycol) catalysts for water electrolysis to produce hydrogen. Therefore, the strategy of combining conductive support graphene with iridium-based multi-element alloy catalysts is an important method for saving costs, improving efficiency and stability, and has significant research potential and industrial prospects. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides a graphene-iridium-based ternary alloy PEM water electrolysis catalyst. By combining graphene, an excellent conductive carrier, with an iridium-based ternary metal catalyst, the problem of excessively high cost of PEM water electrolysis catalyst is solved, and the catalytic activity and stability of water electrolysis are further improved.

[0005] To achieve the above objectives, the present invention adopts the following technical solution, including:

[0006] A method for preparing a graphene-iridium-based ternary alloy PEM electrolysis water catalyst includes the following steps:

[0007] S1. Take iridium source, cobalt source, molybdenum source and graphene and put them into a beaker for thorough mixing. Then, sonicate in an ultrasonic cleaner and then transfer to a magnetic stirrer for stirring until all raw materials are dissolved. Transfer the sample obtained after stirring to a hydrothermal reactor and then place the hydrothermal reactor in a drying oven for heat preservation. After cooling, a black suspension with precipitate is obtained.

[0008] S2, the black suspension with precipitate obtained in step S1 is centrifuged and washed several times, then transferred into a beaker, placed in a drying oven to dry, and after cooling, the black precipitate is obtained and ground into powder.

[0009] S3. The black powder obtained in step S2 is transferred into a corundum crucible and placed in a high-temperature tube furnace for heating treatment. The black powder obtained after cooling is the graphene-iridium-based ternary alloy PEM electrolysis water catalyst.

[0010] Preferably, in step S1, the iridium source is selected from iridium chloride trihydrate; the cobalt source is selected from cobalt chloride hexahydrate; the molybdenum source is selected from molybdenum acetylacetonate; and the graphene is reduced graphene oxide.

[0011] Preferably, in step S1, the mass ratio of the iridium source to the molybdenum source or the cobalt source is 1:1, and the mass ratio of the cobalt source to the molybdenum source is 1:2, 1:1, or 2:1.

[0012] Preferably, in step S1, the ultrasonic cleaning time of the ultrasonic cleaner is 30 minutes or more.

[0013] Preferably, in step S1, the magnetic stirrer rotates at 1000 rpm and the stirring time is 12 hours.

[0014] Preferably, in step S1, the drying oven is a forced-air drying oven with a heat preservation temperature of 170~190℃ and a heat preservation time of 10~12 hours.

[0015] Preferably, in step S2, deionized water is added for centrifugal washing; each centrifugal washing session lasts for 5 minutes, the centrifugation speed is 10,000 rpm, and the number of washing cycles is 3.

[0016] Preferably, in step S2, the drying oven is a vacuum drying oven with a drying temperature of 60°C and a drying time of more than 12 hours.

[0017] Preferably, in step S3, the heating temperature of the high-temperature tubular furnace is 400~800℃, the holding time is 2~4 hours, and the heating rate is 5℃ / minute.

[0018] The graphene-iridium-based ternary alloy PEM electrolytic water catalyst is prepared by the method described above; the catalyst is a ternary metal composite graphene electrocatalyst; wherein the substrate of the catalyst is a graphene layer, and the noble metal iridium and transition metals molybdenum and cobalt are uniformly dispersed on the substrate.

[0019] The advantages of this invention are:

[0020] (1) The ternary metal composite graphene electrocatalyst prepared in this invention has a graphene layer as its substrate, on which the noble metal iridium and the transition metals molybdenum and cobalt are uniformly dispersed. Graphene is an excellent conductive material, and using it as a substrate can promote the activity of the catalyst and reduce the content of noble metals, thereby reducing costs; the addition of transition metals molybdenum and cobalt further increases the activity between the multiple metals, which can further improve the performance of the catalyst.

[0021] (2) The catalyst preparation method developed in this invention significantly improves the activity and stability of OER (oxygen evolution reaction), while greatly reducing production costs and possessing excellent industrialization feasibility. This technology effectively overcomes the limitations of existing proton exchange membrane electrolysis water production technology, providing a breakthrough solution for the field of electrochemical energy storage and hydrogen energy engineering applications.

[0022] (3) In this invention, a graphene-based iridium-based ternary alloy catalyst is used instead of commercial iridium oxide as the anode material for PEM water electrolysis to produce hydrogen, achieving a current density of 10 mA / m. 2 The required overpotential is only 207 mV, which is better than that of commercial iridium oxide catalysts (272 mV). It also has a fast electrode response rate, low electrochemical impedance, large electrochemical active area, and large specific surface area, which significantly improves the catalytic activity of oxygen evolution reaction.

[0023] (4) The graphene-iridium-based ternary alloy catalyst prepared in this invention exhibits improved corrosion resistance and stability during PEM water electrolysis for hydrogen production due to the addition of graphene. At 10 mA / cm², the stability is further enhanced. 2 The voltage rise was less than 3% during a 30-hour test at the specified current density, indicating good stability.

[0024] (5) In this invention, a graphene-based iridium-based ternary alloy catalyst is used instead of commercial iridium oxide as the anode material for PEM water electrolysis to produce hydrogen. Due to the doping of the conductive carrier graphene and the transition metals cobalt and molybdenum, the content of the precious metal iridium is significantly reduced, with an iridium content of approximately 0.07 mg / cm² per unit area. 2 The iridium content is far lower than that in commercial electrolyzers (2~4 mg / cm³). 2This significantly reduces the cost of catalysts. Furthermore, compared to the precious metal iridium, the conductive carrier graphene, as a carbon-based material, has a wide range of sources in nature. With advancements in preparation processes, the cost of graphene will continue to decrease, while the cost of precious metals is unlikely to change significantly. Therefore, the preparation cost of the process described in this invention will continue to decrease along with the price of graphene in the future.

[0025] (6) The graphene-iridium-based ternary alloy catalytic material prepared by the present invention can also achieve large-scale preparation of the material by changing the metal source and graphene content, which is easy to industrialize and has important engineering application value for promoting the large-scale application of PEM electrolysis for hydrogen production. Attached Figure Description

[0026] Figure 1 Transmission electron microscopy (TEM) image of the IrCoMo / rGO-600 sample prepared in Example 1 of this invention.

[0027] Figure 2 High-resolution transmission electron microscopy (HRTEM) image of the IrCoMo / rGO-600 sample prepared in Example 1 of this invention.

[0028] Figure 3 HAADF-STEM image and elemental mapping of the IrCoMo / rGO-600 sample prepared in Example 1 of this invention;

[0029] Figure 4 The EDX spectrum of the IrCoMo / rGO-600 sample prepared in Example 1 of this invention;

[0030] Figure 5 The XRD pattern of the IrCoMo / rGO-600 sample prepared in Example 1 of this invention;

[0031] Figure 6 XPS spectrum of the IrCoMo / rGO-600 sample prepared in Example 1 of this invention;

[0032] Figure 7 The oxygen evolution polarization curves of the catalyst samples prepared in Examples 1-13 of this invention and the comparative sample IrO2 are shown.

[0033] Figure 8 The Tafel slope curves of the IrCoMo / rGO-600, IrCoMo / GE-600 and IrCoMo / GO-600 samples prepared in Examples 1, 6 and 7 of this invention are shown.

[0034] Figure 9Electrochemical impedance spectroscopy curves of IrCoMo / rGO-600, IrCoMo / GE-600 and IrCoMo / GO-600 samples prepared in Examples 1, 6 and 7 of this invention.

[0035] Figure 10 The CV curves and double-layer capacitance diagrams of IrCoMo / rGO-600, IrCoMo / GE-600 and IrCoMo / GO-600 samples prepared in Examples 1, 6 and 7 of this invention are shown below at different scan rates.

[0036] Figure 11 The long-term stability curve of the IrCoMo / rGO-600 sample prepared in Example 1 of this invention on a carbon paper electrode;

[0037] Figure 12 This is a schematic diagram of the catalyst preparation process of the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] This invention provides a graphene-iridium composite ternary alloy PEM electrolysis catalyst for water splitting, wherein the catalyst is a ternary metal composite graphene electrocatalyst; wherein the substrate of the catalyst is a graphene layer, and the noble metal iridium and the transition metals molybdenum and cobalt are uniformly dispersed on the substrate.

[0040] Example 1

[0041] like Figure 12 As shown, the preparation method of graphene-iridium-based ternary alloy PEM electrolysis water catalyst includes the following steps:

[0042] S1. Weigh 10 mg of iridium chloride trihydrate, 5 mg of cobalt chloride hexahydrate, and 5 mg of molybdenum acetylacetonate (cobalt source to molybdenum source mass ratio 1:1) using a balance. Measure 30 mL of deionized water using a graduated cylinder and mix all of them in a 50 mL polytetrafluoroethylene (PTFE) liner. Then, weigh 10 mg of reduced graphene oxide and quickly pour it into the above mixture. Sonicate the mixture for about 10 minutes using an ultrasonic cleaner. Then place the liner on a magnetic stirrer and stir at room temperature for 12 hours at a speed of 1000 rpm to ensure that all raw materials are mixed evenly. At this point, the solution is black. Finally, transfer the liner to a hydrothermal reactor and place it in a forced-air drying oven for hydrothermal reaction at 180℃ for 10 hours. After heating, remove the reactor and allow it to cool naturally to room temperature to obtain a black solution with a precipitate.

[0043] S2, pour the black solution with precipitate obtained in step S1 into a 50mL centrifuge tube, centrifuge at 10000rpm for 5min, remove the tube, and discard the supernatant to obtain the black precipitate. To further wash the precipitate, add 20mL of deionized water and centrifuge at 10000rpm for 5min. Remove the tube, discard the supernatant, and repeat the above steps once more to obtain the centrifuged and washed catalyst. Place the catalyst in a vacuum drying oven at 60℃ and dry for 12h to obtain the black precipitate, which is then ground into a black powder.

[0044] S3. Transfer the dried black powder obtained in step S2 into a corundum crucible and place it in the center of a high-temperature tube furnace. Insulate and seal both ends of the tube with furnace plugs. Purge air with argon gas for half an hour to ensure the catalyst is in an argon atmosphere. Then heat to 600℃ for 3 hours at a rate of 5℃ / min, maintaining argon gas flow throughout the process at a pressure of 0.02-0.04 MPa and a flow rate of 500-600 ml / min. After cooling to room temperature, turn off the argon gas and remove the black powder, which is the catalyst, labeled IrCoMo / rGO-600.

[0045] Example 2

[0046] The difference from Example 1 is that in step S1, the amounts of cobalt chloride hexahydrate and molybdenum acetylacetonate are changed to 10 mg and 0 mg, respectively, that is, the mass ratio of cobalt source to molybdenum source is changed to 1:0. Everything else is the same as in Example 1.

[0047] Example 3

[0048] The difference from Example 1 is that in step S1, the amounts of cobalt chloride hexahydrate and molybdenum acetylacetonate are changed to 6.67 mg and 3.34 mg, respectively, that is, the mass ratio of cobalt source to molybdenum source is changed to 2:1. Everything else is the same as in Example 1.

[0049] Example 4

[0050] The difference from Example 1 is that in step S1, the amounts of cobalt chloride hexahydrate and molybdenum acetylacetonate are changed to 3.34 mg and 6.67 mg, respectively, that is, the mass ratio of cobalt source to molybdenum source is changed to 1:2. Everything else is the same as in Example 1.

[0051] Example 5

[0052] The difference from Example 1 is that in step S1, the amounts of cobalt chloride hexahydrate and molybdenum acetylacetonate are changed to 0 mg and 10 mg, respectively, that is, the mass ratio of cobalt source to molybdenum source is changed to 0:1. Everything else is the same as in Example 1.

[0053] Example 6

[0054] The difference from Example 1 is that in step S1, the type of graphene added is changed to 10mg of single-layer graphene, while everything else is the same as in Example 1.

[0055] Example 7

[0056] The difference from Example 1 is that in step S1, the type of graphene added is changed to 10mg of graphene oxide, while everything else is the same as in Example 1.

[0057] Example 8

[0058] The difference from Example 1 is that in step S3, the heating temperature of the high-temperature tubular furnace is changed to 400°C, while everything else is the same as in Example 1.

[0059] Example 9

[0060] The difference from Example 1 is that in step S3, the heating temperature of the high-temperature tubular furnace is changed to 500°C, while everything else is the same as in Example 1.

[0061] Example 10

[0062] The difference from Example 1 is that in step S3, the heating temperature of the high-temperature tubular furnace is changed to 700°C, while everything else is the same as in Example 1.

[0063] Example 11

[0064] The difference from Example 1 is that in step S3, the heating temperature of the high-temperature tubular furnace is changed to 800°C, while everything else is the same as in Example 1.

[0065] Example 12

[0066] The difference from Example 1 is that in step S3, the heating time of the high-temperature tubular furnace is changed to 2 hours, while everything else is the same as in Example 1.

[0067] Example 13

[0068] The difference from Example 1 is that in step (c), the heating time of the high-temperature tubular furnace is changed to 4 hours, while everything else is the same as in Example 1.

[0069] The catalysts prepared in the above examples were subjected to physical characterization tests, and the test results are as follows:

[0070] Figure 1 This is a transmission electron microscope (TEM) image of IrCoMo / rGO-600 prepared in Example 1 of this invention. See also... Figure 1It can be observed that the IrCoMo / rGO-600 sample prepared by hydrothermal method and high temperature heat treatment exhibits a sheet-like structure, which is graphene nanosheets. Numerous nanospheres are uniformly covered on the surface of the nanosheets. These nanospheres are extremely small, which can expose more active area and improve catalytic activity.

[0071] Figure 2 This is an HRTEM image (high-resolution transmission electron microscope image) of IrCoMo / rGO-600 prepared in Example 1 of this invention. See also... Figure 2 It can be observed that the diameter of the nanospheres is about 2~3 nm and the lattice spacing is about 0.230 nm.

[0072] Figure 3 These are HAADF-STEM images (scanning transmission images) and elemental mapping diagrams of IrCoMo / rGO-600 prepared in Example 1 of this invention. Figure 3 In the image, (a) is the HAADF-STEM image, (b) is a surface scan of a mixture of Ir, Co, Mo, and C, and (c), (d), (e), and (f) are individual surface scans of Ir, Mo, Co, and C, respectively. See also... Figure 3 It can be observed that the sample presents a sheet-like structure mainly based on graphene (C), with Ir, Co and Mo elements relatively uniformly covering it, without obvious agglomeration, which would reduce the activity.

[0073] Figure 4 This is the EDX spectrum of IrCoMo / rGO-600 prepared in Example 1 of this invention. (See also...) Figure 4 It can be observed that the elemental energy of C in the sample is the most obvious, followed by Ir, while the characteristic peaks of Co and Mo are relatively weak. The relative contents of each element are shown in Table 1.

[0074] Table 1. Relative content percentage of each element in Example 1

[0075] ;

[0076] Figure 5 This is the XRD pattern of IrCoMo / rGO-600 prepared in Example 1 of this invention. (See also...) Figure 5It can be observed that the peak at 26.4° is the (002) plane of graphene (C, JCPDS: 00-041-1487), indicating the presence of graphene sheets; Ir and Co have obvious characteristic peaks at 40.6° and 45.9°, corresponding to the positions of the (111) planes of each element, with lattice spacing of 0.222nm (Ir, JCPDS: 01-006-0598) and 0.205nm (Co, JCPDS: 01-088-2335); MoO2 has an obvious characteristic peak at 26.0°, corresponding to the position of the (011) plane, with lattice spacing of 0.342nm (Mo, JCPDS: 01-086-0135). Therefore, the lattice spacing of IrCoMo / rGO-600 should satisfy 0.205~0.342nm, which is consistent with the TEM lattice spacing of 0.230nm.

[0077] Figure 6 These are the XPS (X-ray photoelectron spectra) of each element in IrCoMo / rGO-600 prepared in Example 1 of this invention. Figure 6 In the diagram, (a) is the overall spectrum, and (b), (c), (d), (e), and (f) are specific narrow diagrams of the five elements Ir, Co, Mo, C, and O, respectively. (See also...) Figure 6 It can be observed that five elements, Ir, Co, Mo, C, and O, are present. Among them, the metallic element Ir mainly exists in the 0 and 4 valence states, Co mainly exists in the 0 and 3 valence states, and Mo mainly exists in the 0 and 6 valence states. The non-metallic element C has four characteristic peaks, among which the C1 peak is particularly significant compared to the other three peaks. This is due to the addition of graphene. O has three characteristic peaks: O1 is lattice oxygen, O2 is surface oxygen, and O3 is adsorbed oxygen.

[0078] The electrochemical performance of the catalysts prepared in the above examples was tested, and the results are as follows:

[0079] This invention employs a three-electrode system for electrochemical performance testing, evaluating performance through changes in the oxygen evolution reaction during water electrolysis for hydrogen production. The three-electrode system consists of a working electrode, a counter electrode, and a reference electrode, with the sample electrode serving as the working electrode, a platinum wire electrode as the counter electrode, and a saturated silver chloride electrode as the reference electrode. The electrolyte is a 0.5M H₂SO₄ solution.

[0080] The test conditions for this invention are as follows:

[0081] Test temperature: room temperature (25~28℃);

[0082] Linear scan voltage range: 1.197~1.597V (relative to reversible hydrogen electrode);

[0083] Linear scan rate: 5mV / s;

[0084] Electrochemical impedance voltage: 1.5V (relative to the reversible hydrogen electrode);

[0085] Frequency range for impedance testing: 10 5 ~0.01Hz;

[0086] CV cycling voltage range: 0.9~1.0V (relative to reversible hydrogen electrode);

[0087] CV cycle scan rates: 5, 10, 20, 40, 60, 80, 100 mV / s;

[0088] Constant current density for stability testing: 10 mA / cm² 2 .

[0089] The preparation method of the working electrode in this invention is as follows: First, take 5 mg of the prepared catalyst and add it to 1 mL of anhydrous ethanol, sonicate for more than 20 minutes to form a suspension after thorough mixing.

[0090] (1) Glassy carbon electrode: Use a pipette to measure 5 μL of suspension and drop it onto a glassy carbon electrode with a diameter of 3 mm. After drying at room temperature for 10-15 min, repeat the above steps once. Then use a pipette to measure 5 μL of 0.5 wt% Nafion solution and drop it onto the glassy carbon electrode. After drying at room temperature, it is ready for use.

[0091] Meanwhile, a control working electrode was prepared using commercial IrO2 as a control catalyst according to the above method.

[0092] It should be noted that, except for long-term stability tests, glassy carbon electrodes were used as test electrodes (working electrodes).

[0093] (2) Carbon paper electrode: cut into 1×1cm pieces 2 The carbon paper was sonicated in acetone, anhydrous ethanol, and deionized water for 10 minutes each, then dried in a 60°C oven for 2 hours before use. 143 μL of the suspension and 71.5 μL of 0.5 wt% Nafion solution were measured using a pipette, thoroughly mixed, and then 54 μL of the mixture was dropped onto a 1×1 cm... 2 The carbon paper electrode is dried in a drying oven at 60°C for 5-10 minutes, and the above steps are repeated 3 times. Finally, it is dried in a drying oven at 60°C for 6 hours before use.

[0094] Figure 7 These are the oxygen evolution polarization curves of the catalyst samples prepared in all embodiments of the present invention and the comparative sample IrO2. Figure 7In the figures, (a) shows the oxygen evolution polarization curves of Examples 1-7, and (b) shows the oxygen evolution polarization curves of Examples 8-13 and the comparative sample IrO2. The overpotentials corresponding to each sample are shown in Table 2. It can be seen that the current density is 10 mA / cm². 2 At that time, the IrCoMo / rGO-600 prepared in Example 1 had the best oxygen evolution catalytic activity, with an overpotential of only 207mV.

[0095] Table 2. Reaction conditions and corresponding overpotentials for Examples 1-13 and the control group.

[0096] ;

[0097] Figure 8 Tafel slope curves for IrCoMo / rGO-600, IrCoMo / GE-600, and IrCoMo / GO-600 prepared in Examples 1, 6, and 7. (See also...) Figure 8 It can be observed that the Tafel slopes of IrCoMo / rGO-600, IrCoMo / GE-600, and IrCoMo / GO-600 are 74.5 mV / dec, 79.4 mV / dec, and 103.9 mV / dec, respectively. IrCoMo / rGO-600 has the smallest Tafel slope, indicating that its electrode response rate is the fastest.

[0098] Figure 9 Electrochemical impedance spectroscopy (EIS) curves for IrCoMo / rGO-600, IrCoMo / GE-600, and IrCoMo / GO-600 prepared in Examples 1, 6, and 7, respectively. (See attached image.) Figure 9 It can be observed that the semicircle diameter of IrCoMo / rGO-600 is the smallest, indicating that its electrochemical impedance value is the smallest.

[0099] Figure 10 The CV curves and double-layer capacitance diagrams of IrCoMo / rGO-600, IrCoMo / GE-600, and IrCoMo / GO-600 prepared in Examples 1, 6, and 7 are shown. Figure 10 In the figure, (a), (b), and (c) are the CV curves of IrCoMo / rGO-600, IrCoMo / GE-600, and IrCoMo / GO-600, respectively, and (d) is the double-layer capacitance diagram. See also... Figure 10 It can be observed that IrCoMo / rGO-600 has the largest double-layer capacitance, indicating that it has the largest electrochemical active area.

[0100] Figure 11 The stability curve of IrCoMo / GO-600 prepared in Example 1 on a carbon paper electrode. (See attached image.) Figure 11It can be observed that after a long test of 30 hours, the voltage of IrCoMo / GO-600 increased by less than 3%, demonstrating the good stability of the catalyst sample.

[0101] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of preparing a graphene composite iridium-based ternary alloy PEM electrolysis water catalyst, characterized by, The method comprises the following steps: S1, taking an iridium source, a cobalt source, a molybdenum source and graphene into a beaker for mixing, and then ultrasonic cleaning in an ultrasonic cleaner, and then moving to a magnetic stirrer for stirring until each raw material is dissolved, and then moving the obtained sample after stirring into a hydrothermal reaction kettle, and then placing the hydrothermal reaction kettle into a drying box for heat preservation, and then obtaining a black suspension with precipitate after cooling; S2, centrifugal washing the black suspension with precipitate obtained in step S1 for several times, and then moving into a beaker and placing into a drying box for drying, and then obtaining black precipitate after cooling and grinding into powder; S3, moving the black powder obtained in step S2 into a corundum crucible, and then placing into a high-temperature tube furnace for heating treatment, and then obtaining the black powder after cooling, which is the graphene composite iridium-based ternary alloy PEM electrolytic water catalyst; In step S1, the graphene is reduced graphene oxide; the iridium source is selected from iridium chloride trihydrate; the cobalt source is selected from cobalt chloride hexahydrate; and the molybdenum source is selected from molybdenum acetylacetone; In step S1, the mass ratio of the iridium source to the molybdenum source or the cobalt source is 1:1, and the mass ratio of the cobalt source to the molybdenum source is 1:2, 1:1 or 2:1; In step S3, the heating temperature of the high-temperature tube furnace is 400-800℃, the heat preservation time is 2-4 hours, and the temperature rising rate is 5℃ / min.

2. The preparation method of the graphene-iridium-based ternary alloy PEM electrolysis catalyst according to claim 1, characterized in that, In step S1, the ultrasonic time of the ultrasonic cleaner is more than 30 minutes.

3. The preparation method of the graphene-iridium-based ternary alloy PEM electrolysis water catalyst according to claim 1, characterized in that, In step S1, the rotating speed of the magnetic stirrer is 1000 rpm, and the stirring time is 12 hours.

4. The preparation method of the graphene-iridium-based ternary alloy PEM electrolysis catalyst according to claim 1, characterized in that, In step S1, the drying box is a blast drying box, the heat preservation temperature is 170-190℃, and the heat preservation time is 10-12 hours.

5. The preparation method of the graphene-iridium-based ternary alloy PEM electrolysis water catalyst according to claim 1, characterized in that, In step S2, the centrifugal washing is added with deionized water, the centrifugal washing time is 5 minutes each time, the centrifugal rotating speed is 10000 rpm, and the washing times are 3 times.

6. The preparation method of the graphene-iridium-based ternary alloy PEM electrolysis water catalyst according to claim 1, characterized in that, In step S2, the drying box is a vacuum drying box, the drying temperature is 60℃, and the drying time is more than 12 hours.

7. A graphene-composite iridium-based ternary alloy PEM electrolysis water catalyst characterized by, The catalyst is prepared by the preparation method in any one of claims 1-6; the catalyst is a ternary metal composite graphene electrocatalyst; wherein the catalyst has a graphene layer as a substrate, and noble metal iridium and transition metal molybdenum and cobalt are uniformly dispersed on the substrate.

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