Catalyst with gallium-doped iridium-vanadium intermetallic compound loaded on carbon carrier as well as preparation method and application of catalyst

Abstract

The invention belongs to the technical field of electrolyzed water catalysts, and particularly relates to a catalyst with a gallium-doped iridium-vanadium intermetallic compound loaded on a carbon carrier and a preparation method and application thereof.The preparation method includes the following preparation steps that 1, iridium salt, vanadium salt, gallium salt and the carbon carrier are dispersed in a solvent to obtain a mixture, the molar ratio of iridium atoms to vanadium atoms to gallium atoms is 30: (8-9.5): (0.5-2); then heating the mixture to evaporate the solvent to dryness, carrying out vacuum drying on an obtained sample, and grinding to obtain precursor solid powder; and (2) annealing the precursor solid powder in a reducing atmosphere to obtain the gallium-doped iridium-vanadium intermetallic compound loaded carbon carrier catalyst. Cheap low-melting-point metal gallium is introduced into an iridium-vanadium ordered intermetallic compound catalyst, so that the ordering degree of the ordered intermetallic compound is improved, and the problems of low activity and high cost of a water electrolysis catalyst are effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of water electrolysis catalysts, and specifically relates to a catalyst in which a gallium-doped iridium-vanadium intermetallic compound is loaded on a carbon carrier, and a preparation method and application thereof. Background Art

[0002] With the rapid development of society, people's demand for energy is increasing day by day. However, the extensive use of traditional fossil fuels such as coal and oil will cause environmental problems such as global warming, acid rain and ozone layer depletion. Therefore, building a clean, low-carbon and efficient energy system is of great significance to achieving sustainable development. Hydrogen energy, as a green energy, has the advantages of high energy density, wide sources, clean and pollution-free, and has great development potential. Water electrolysis hydrogen production technology has become an important way to produce green hydrogen due to its safe preparation process, high purity of hydrogen production, and immediate use. Converting electrical energy stored in intermittent renewable energy into chemical energy-hydrogen energy through water electrolysis technology will help reduce dependence on fossil fuels, solve environmental problems, promote the transformation of energy structure, and alleviate the energy crisis.

[0003] At present, acidic proton exchange membrane electrolyzers (PEMWEs) and alkaline electrolyzers (AWEs) have formed a certain scale in the practical application of hydrogen production by water electrolysis. Compared with traditional AWEs, PEMWEs are compact in structure, can be effectively coupled with intermittent electricity from renewable energy sources (such as solar and wind energy), and can show advantages such as high flexibility and fast response under high dynamic operating conditions. In addition, PEMWEs also have the advantages of higher working current density, faster hydrogen production rate and wider working temperature and pressure range. Iridium (Ir)-based and ruthenium (Ru)-based materials are widely used in the oxygen evolution reaction (Oxygen evolution reaction, OER) at the anode and hydrogen evolution reaction (Hydrogen evolution reaction, HER) at the cathode in acidic water electrolysis. Although Ru-based materials have high catalytic activity, soluble RuO4 will be formed at high potential, resulting in poor stability in acidic electrolytes. In contrast, Ir-based materials have the advantages of corrosion resistance and high catalytic activity, so they can have excellent activity and stability in acidic OER and HER.

[0004] Alloying Ir with transition metals is a widely used optimization strategy. The introduction of transition metals can reduce the Ir loading, reduce the catalyst preparation cost, and improve the economy. In addition, the introduction of transition metals can also change the electronic structure of Ir, thereby optimizing its adsorption strength for oxygen-containing intermediates in the OER process, improving its catalytic activity, and thus improving the efficiency of hydrogen production from water electrolysis. However, in traditional disordered alloys, transition metals are easily corroded and dissolved by strong acid electrolytes, resulting in a rapid decay of their catalytic activity. Therefore, it is urgent to develop Ir-based bifunctional catalysts for acidic OER and HER that meet the requirements of low cost, high activity, and high stability. Summary of the invention

[0005] In view of the defects of the prior art, the present invention provides a catalyst of a gallium-doped iridium-vanadium intermetallic compound loaded on a carbon carrier, and a preparation method and application thereof, the purpose of which is to solve the technical problems of low catalytic efficiency, high cost and low stability of the catalyst in the reaction of electrolyzing water to prepare hydrogen and oxygen in the prior art.

[0006] To achieve the above object, according to a first aspect of the present invention, the present invention provides a method for preparing a catalyst of a gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier, comprising the following preparation steps:

[0007] (1) dispersing an iridium salt, a vanadium salt, a gallium salt and a carbon carrier in a solvent to obtain a mixture, wherein the molar ratio of iridium, vanadium and gallium atoms in the iridium salt, vanadium salt and gallium salt is 30:(8-9.5):(0.5-2); then heating the mixture to evaporate the solvent, vacuum drying the obtained sample and grinding it to obtain a precursor solid powder;

[0008] (2) annealing the precursor solid powder in a reducing atmosphere to obtain a catalyst in which a gallium-doped iridium-vanadium intermetallic compound is supported on a carbon carrier.

[0009] Preferably, the annealing heating rate is 3-10° C. / min, the annealing temperature is 600-900° C., and the annealing time is 2-8 h.

[0010] Preferably, the mass of iridium atoms in the iridium salt accounts for 10-50% of the total mass of the iridium salt, the vanadium salt, the gallium salt and the carbon carrier.

[0011] Preferably, the iridium salt is one or more of chloroiridic acid, iridium acetylacetonate, and iridium acetate; the vanadium salt is one or more of vanadium trichloride, vanadium acetylacetonate, and vanadium acetate; the gallium salt is one or more of gallium nitrate, gallium acetate, and gallium acetylacetonate; the carbon carrier is one or more of carbon black, graphene, carbon nanotubes, and carbon nanowires.

[0012] Preferably, the reducing atmosphere is a mixed gas of hydrogen and argon, wherein the volume ratio of hydrogen is 5-10%; and the solvent is one or both of water and ethanol.

[0013] Preferably, in step (1), ultrasound and stirring are also performed during the heating process; the ultrasound time is 0.5 to 2 hours, and the stirring speed is 300 to 500 rpm; in step (1), the heating temperature is 55°C to 70°C.

[0014] According to another aspect of the present invention, there is provided a catalyst in which the gallium-doped iridium-vanadium intermetallic compound prepared by the preparation method is supported on a carbon carrier.

[0015] Preferably, it is used as a catalyst for electrolyzing water to produce hydrogen and oxygen, wherein the electrolyzed water is selected from an aqueous sulfuric acid solution or an aqueous perchloric acid solution.

[0016] Preferably, the concentrations of the aqueous sulfuric acid solution and the aqueous perchloric acid solution are both 0.1 to 0.5 mol / L. In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0017] (1) The present invention introduces cheap low-melting-point metal gallium into the iridium-vanadium ordered metal intermetallic compound catalyst, and controls the molar ratio of iridium, vanadium and gallium atoms in the iridium salt, vanadium salt and gallium salt to be 30:(8-9.5):(0.5-2). The low-melting-point gallium metal can induce the weakening of the strength of the metal bond between iridium and vanadium, further reduce the reaction activation energy of the system, and promote the ordering process of the metal intermetallic compound. This can not only improve the degree of ordering of the ordered metal intermetallic compound, but also utilize the electronic effect to achieve the improvement of the activity and stability of the iridium-based ordered metal intermetallic compound. At the same time, the introduction of metal gallium can also reduce the cost of the iridium-based catalyst, improve the catalytic activity while ensuring the catalytic stability, and effectively solve the problem of low activity and high cost of the water electrolysis catalyst.

[0018] (2) The present invention disperses iridium salt, vanadium salt, gallium salt and carbon carrier in a solvent, anneals in a reducing atmosphere after drying, and prepares a gallium-doped iridium-vanadium intermetallic compound supported on carbon nanoparticle alloy catalyst by an impregnation-reduction method. The synthetic method provided by the present invention has readily available raw materials and is simple to operate, and can achieve large-scale preparation.

[0019] (3) The present invention obtains gallium-doped iridium-vanadium intermetallic compounds by controlling the annealing heating rate to 3-10°C / min, the annealing temperature to 600-900°C, and the annealing time to 2-8h. The intermetallic compounds have lower formation enthalpy and stronger interatomic interaction, and their anti-oxidation and anti-corrosion properties are significantly improved. In addition, the atoms of each constituent element in the ordered intermetallic compound have specific positions, so that predictable regulation of the structure and electronic effects can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 X-ray diffraction (XRD) patterns of the gallium-doped iridium-vanadium intermetallic compound supported on carbon catalyst with annealing temperatures of 600° C., 700° C., 800° C. and 900° C. in Example 1.

[0021] Figure 2 The XRD patterns of the catalysts of gallium-doped iridium-vanadium intermetallic compounds supported on carbon with annealing times of 2 h, 4 h, 6 h and 8 h in Example 2.

[0022] Figure 3 1 is the XRD spectrum of the catalyst of gallium-doped iridium-vanadium intermetallic compound supported on carbon after being doped with different molar amounts of gallium in Example 3.

[0023] Figure 4 This is the X-ray photoelectron spectroscopy (XPS) spectrum of the gallium-doped iridium-vanadium intermetallic compound catalyst supported on carbon at an annealing temperature of 800° C. in Example 1.

[0024] Figure 5 The OER-linear sweep voltammetry (LSV) polarization curves of the gallium-doped iridium-vanadium intermetallic compound supported on carbon catalyst with annealing temperatures of 600°C, 700°C, 800°C and 900°C in Example 1.

[0025] Figure 6 ] are the OER-LSV polarization curves of the gallium-doped iridium-vanadium intermetallic compound supported on carbon catalyst annealed for 2h, 4h, 6h and 8h in Example 2.

[0026] Figure 7 : This is the OER-LSV polarization curve of the gallium-doped iridium-vanadium intermetallic compound catalyst supported on carbon after being doped with different molar amounts of gallium in Example 3.

[0027] Figure 8 The OER-LSV polarization curves of the catalyst of Example 1 in which the gallium-doped iridium-vanadium intermetallic compound is supported on carbon, and the catalysts of Comparative Examples 1, 2 and 3.

[0028] Fig. 9HER-LSV polarization curves of the catalyst of Example 1 in which gallium-doped iridium-vanadium intermetallic compound is supported on carbon, and the catalysts of Comparative Examples 1, 2 and 4.

[0029] Fig.10 This is a stability curve of the catalyst of gallium-doped iridium-vanadium intermetallic compound supported on carbon in OER in Example 1.

[0030] Fig.11 This is a stability curve of the catalyst of gallium-doped iridium-vanadium intermetallic compound supported on carbon in HER in Example 1. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Example 1

[0033] This embodiment provides a catalyst of a gallium-doped iridium-vanadium intermetallic compound supported on carbon, and the preparation method thereof is as follows:

[0034] 40 mg of carbon black, chloroiridic acid, vanadium trichloride and gallium nitrate were uniformly dispersed in 5 mL of water, ensuring that the molar ratio of iridium, vanadium and gallium atoms in chloroiridic acid, vanadium trichloride and gallium nitrate was 30:9:1, and ultrasonically stirred for 0.5 h. The resulting mixed solution was stirred and ultrasonically stirred at 60 ° C until the water solvent was evaporated to dryness to obtain a solid product, which was ground in an agate mortar to obtain a precursor solid powder, and the obtained precursor solid powder was annealed in a mixed atmosphere of Ar and H2, wherein the volume fraction of H2 was 5%, the annealing rate was 10 ° C / min, the annealing temperatures were 600 ° C, 700 ° C, 800 ° C and 900 ° C, respectively, and the annealing time was 6 h. The catalyst obtained by annealing at 800 ° C for 6 h was recorded as Ir3V 0.9 Ga 0.1 .

[0035] Example 2

[0036] 40 mg of carbon black, chloroiridic acid, vanadium trichloride and gallium nitrate were uniformly dispersed in 5 mL of water, ensuring that the molar ratio of iridium, vanadium and gallium atoms in chloroiridic acid, vanadium trichloride and gallium nitrate was 30:9:1, and ultrasonically stirred for 0.5 h. The resulting mixed solution was stirred and ultrasonically stirred at 60 ° C until the water solvent was evaporated to dryness to obtain a solid product, which was ground in an agate mortar to obtain a precursor solid powder, and the obtained precursor solid powder was annealed in a mixed atmosphere of Ar and H2, wherein the volume fraction of H2 was 5%, the annealing rate was 10 ° C / min, the annealing temperature was 800 ° C, and the annealing time was 2h, 4h, 6h and 8h respectively.

[0037] Example 3

[0038] 40 mg of carbon black, chloroiridic acid, vanadium trichloride and gallium nitrate are uniformly dispersed in 5 mL of water, ensuring that the molar ratios of iridium, vanadium and gallium atoms in chloroiridic acid, vanadium trichloride and gallium nitrate are 3:0.95:0.05, 3:0.9:0.1, 3:0.85:0.15 and 3:0.8:0.2 respectively (wherein the molar amount of gallium atoms accounts for 5%, 10%, 15% and 20% of the total molar amount of vanadium and gallium atoms respectively), and ultrasonically stirred for 0.5 h. The resulting mixed solution is stirred and ultrasonically stirred at 60 ° C until the water solvent is evaporated to dryness to obtain a solid product, and the solid product is ground in an agate mortar to obtain a precursor solid powder, and the obtained precursor solid powder is annealed in a mixed atmosphere of Ar and H2, wherein the volume fraction of H2 is 5%, the annealing rate is 10 ° C / min, the annealing temperature is 800 ° C, and the annealing time is 6 h.

[0039] Comparative Example 1

[0040] This comparative example provides a catalyst of an iridium-vanadium intermetallic compound supported on carbon as a comparative sample, and its preparation method is as follows:

[0041] 40 mg of carbon black, chloroiridic acid and vanadium trichloride were uniformly dispersed in 5 mL of water, ensuring that the molar ratio of iridium to vanadium in chloroiridic acid and vanadium trichloride was 3:1, and ultrasonically stirred for 0.5 h. The resulting mixed solution was stirred and ultrasonically stirred at 60 ° C until the water solvent was evaporated to dryness to obtain a solid product, which was ground in an agate mortar to obtain a precursor solid powder, and the obtained precursor solid powder was annealed in a mixed atmosphere of Ar and H2, wherein the volume fraction of H2 was 5%, the annealing rate was 10 ° C / min, the annealing temperature was 800 ° C, and the annealing time was 6 h.

[0042] Comparative Example 2

[0043] This comparative example provides a catalyst in which iridium element is supported on carbon as a comparative sample, and the preparation method thereof is as follows:

[0044] 40 mg of carbon black and 0.052 mol of chloroiridic acid were uniformly dispersed in 5 mL of water, and ultrasonicated and stirred for 0.5 h. The resulting mixed solution was stirred and ultrasonicated at 60 ° C until the water solvent was evaporated to dryness to obtain a precursor solid powder, which was annealed in a mixed atmosphere of Ar and H2, wherein the volume fraction of H2 was 5%, the annealing rate was 10 ° C / min, the annealing temperature was 200 ° C, and the annealing time was 2 h.

[0045] Comparative Example 3

[0046] This comparative example provides a commercial iridium dioxide as a comparative sample.

[0047] Comparative Example 4

[0048] This comparative example provides a catalyst in which a single substance of platinum is supported on carbon as a comparative sample, and the preparation method thereof is as follows:

[0049] 40 mg of carbon black and 0.052 mol of chloroplatinic acid were uniformly dispersed in 5 mL of water, and ultrasonically stirred for 0.5 h. The resulting mixed solution was stirred and ultrasonically stirred at 60 ° C until the water solvent was evaporated to dryness to obtain a precursor solid powder, which was annealed in a mixed atmosphere of Ar and H2, wherein the volume fraction of H2 was 5%, the annealing rate was 10 ° C / min, the annealing temperature was 200 ° C, and the annealing time was 2 h.

[0050] The gallium-doped iridium-vanadium intermetallic compound loaded on carbon catalyst prepared in Example 1, Example 2 and Example 3, and the iridium-vanadium intermetallic compound loaded on carbon catalyst (Ir3V / C), iridium element loaded on carbon catalyst (Ir / C), iridium dioxide (IrO2) and platinum element loaded on carbon catalyst (Pt / C) prepared in Comparative Examples 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 were respectively subjected to an acidic water electrolysis anode oxygen evolution reaction test (OER test) and an acidic water electrolysis cathode hydrogen evolution reaction test (HER test) according to the above-mentioned implementation manner.

[0051] For the OER test, 5 mg of catalyst powder was added to 1 mL of a mixed solution of isopropanol and perfluorosulfonic acid polymer (Nafion) to prepare ink (0.1 wt% Nafion). The ink was ultrasonically mixed for 0.5 h to make it evenly mixed, and 10 μL of ink was measured using a micro-injector. It was dripped on the surface of the glassy carbon electrode in small amounts and multiple times, and dried naturally in the air. This was used as the working electrode, the platinum wire electrode as the auxiliary electrode, and the reversible hydrogen electrode as the reference electrode, and the electrochemical test was carried out using a three-electrode system. The electrolyte solution was a freshly prepared 0.1 M HClO4 electrolyte. N2 was passed through the 0.1 M HClO4 electrolyte for 0.5 h to saturate it, and activated for 250 cycles in the range of 0.05-1.45 V (relative to the standard hydrogen electrode), with a scan rate of 0.2 V s-1 Replace the electrolyte with fresh 0.1M HClO4 and saturate it with O2 for 0.5h. Set the speed to 1600rpm and scan at a voltage range of 1.2 to 1.8V (relative to standard hydrogen electrode) at a rate of 0.005V s -1 Scan and obtain the LSV curve.

[0052] The stability of the catalyst was evaluated by accelerated stability test (ADT), i.e., the catalyst was heated to 0.2 V s in 0.1 M HClO4 saturated with O2 at a voltage range of 1.2–1.6 V (vs. SHE). -1 The scanning speed was scanned for different numbers of cycles, and then a fresh electrolyte solution was replaced for LSV test, and the changes of LSV curves before and after ADT were compared. The catalyst of gallium-doped iridium-vanadium intermetallic compound supported on carbon prepared in Example 1 was tested for OER stability by ADT.

[0053] For HER testing, 5 mg of catalyst powder was added to 1 mL of isopropanol / Nafion mixed solution to prepare ink (0.1 wt% Nafion). The ink was ultrasonically mixed for 0.5 h. 10 μL of ink was measured using a microinjector and applied in small amounts and multiple times on the surface of the glassy carbon electrode, and dried naturally in the air. This was used as the working electrode, the platinum wire electrode as the auxiliary electrode, and the reversible hydrogen electrode as the reference electrode. The electrolyte solution was a freshly prepared 0.1 M HClO4 electrolyte. H2 was passed through the 0.1 M HClO4 electrolyte for 0.5 h to saturate it, the speed was set to 1600 rpm, and the voltage range was -0.3 to 0.05 V (relative to the standard hydrogen electrode) at a scanning speed of 0.005 V s -1 The LSV curve was obtained by scanning.

[0054] The stability of the catalyst was evaluated by ADT, i.e., the catalyst was heated to 0.2 V s in a voltage range of -0.3 to 0.05 V (relative to standard hydrogen electrode) in 0.1 M HClO4 saturated with H2. -1 The scanning speed was scanned for different numbers of cycles, and then a fresh electrolyte solution was replaced for LSV test, and the changes of LSV curves before and after ADT were compared. The gallium-doped iridium-vanadium intermetallic compound catalyst loaded on carbon prepared in Example 1 was subjected to HER stability test using ADT.

[0055] Figure 1The XRD patterns of the catalysts of gallium-doped iridium-vanadium intermetallic compounds supported on carbon annealed at 600°C, 700°C, 800°C and 900°C for 6h in Example 1. As can be seen from the figure, the broad peaks of all materials at around 25° are attributed to the diffraction peaks of the (002) plane of the carbon support. The diffraction peaks of the Ir3V catalyst are consistent with the standard material card (PDF#03-065-6779), which is a face-centered cubic (fcc) crystal phase structure. The diffraction peak at 33.2° corresponds to the (110) superlattice, indicating the successful synthesis of the ordered phase Ir3V. Ir3V 0.9 Ga 0.1 The (111) diffraction peak of Ir3V becomes sharper with increasing annealing temperature, which can be attributed to the increase in grain size caused by high temperature heat treatment. 0.9 Ga 0.1 The fcc crystal structure was formed at different annealing temperatures. No (110) superlattice appeared at 600℃, that is, no ordered structure was formed. As the temperature increased, the diffraction peak intensity of the (110) crystal plane increased, indicating that Ir3V 0.9 Ga 0.1 The order degree increases with the increase of temperature and reaches the highest level at 800℃.

[0056] Figure 2 The XRD patterns of the catalysts of the gallium-doped iridium-vanadium intermetallic compound supported on carbon and annealed at 800°C for 2h, 4h, 6h and 8h in Example 2. It can be seen from the figure that the diffraction peak intensity of the (110) crystal plane of the catalyst obtained by prolonging the heat treatment time and doping Ga into the iridium-vanadium intermetallic compound increases, indicating that the order is improved, and the Ir3V 0.9 Ga 0.1 Annealing for 6h shows a more obvious (210) diffraction peak, indicating that its order is higher. Calculation shows that the highest order is 94%.

[0057] Figure 3 The XRD patterns of the catalyst of gallium-doped iridium-vanadium intermetallic compound supported on carbon after annealing at 800°C for 6h and doping with different molar amounts of gallium in Example 3. As can be seen from the figure, the more gallium doping, the more obvious the exposure of each crystal face, but the order shows the characteristics of first increasing and then decreasing. This is because more Ga atoms enter the Ir lattice, causing the lattice to stretch, the interplanar spacing to increase, and the order to decrease.

[0058] Figure 4 Ir3V after annealing at 800℃ for 6h in Example 1 0.9 Ga 0.1 XPS spectrum. It can be seen that there are five elements, Ir, V, Ga, C and O, in the sample. The presence of O is due to the inevitable oxidation caused by the sample being exposed to air.

[0059] Figure 5 The OER-LSV polarization curves of the gallium-doped iridium-vanadium intermetallic compound supported on carbon catalyst at 600°C, 700°C, 800°C and 900°C in Example 1, and the electrolyte solution is a 0.1M HClO4 solution. It shows that with the increase of annealing temperature, the activity of the catalyst increases first and then decreases. At 800°C, the active sites of the catalyst are most exposed and the performance is the best.

[0060] Figure 6 The OER-LSV polarization curves of the gallium-doped iridium-vanadium intermetallic compound supported on carbon catalyst annealed at 800°C for 2h, 4h, 6h and 8h in Example 2, the electrolyte solution is 0.1M HClO4 solution. With the increase of annealing time, the degree of ordering increases and then decreases, 10mA cm -2 The overpotential at first decreases and then increases, and the activity first increases and then decreases.

[0061] Figure 7 The OER-LSV polarization curves of the catalysts doped with gallium and supported on carbon after annealing at 800℃ for 6h and doping with different molar amounts of gallium in Example 3. The electrolyte solution is 0.1M HClO4 solution. It can be found that as the proportion of doped gallium increases, the 10mA cm -2 The overpotential at shows a trend of first decreasing and then increasing, that is, when the molar amount of gallium doping accounts for 10% of the total molar amount of vanadium and gallium atoms, the OER performance of the catalyst is optimal.

[0062] Figure 8 The OER-LSV polarization curves of the catalyst of gallium-doped iridium-vanadium intermetallic compound supported on carbon annealed at 800°C for 6h in Example 1 and Comparative Example 1 (Ir3V / C), Comparative Example 2 (Ir / C) and Comparative Example 3 (IrO2), and the electrolyte solution is 0.1M HClO4 solution. When the annealing temperature is 800°C and the annealing time is 6h, it can be seen from the figure that the OER activity of the catalyst of Example 1 is the best, and is better than Comparative Example 1, Comparative Example 2 and Comparative Example 3, which indicates that the introduction of gallium element improves the order and catalytic activity of the material.

[0063] Fig. 9 The HER-LSV polarization curves of the catalyst of gallium-doped iridium-vanadium intermetallic compound supported on carbon annealed at 800°C for 6h in Example 1 and Comparative Example 1 (Ir3V / C), Comparative Example 2 (Ir / C) and Comparative Example 4 (Pt / C), and the electrolyte solution is 0.1M HClO4 solution. It can be seen from the figure that the activity of the catalyst of Example 1 is better than that of the catalysts of Comparative Example 1, Comparative Example 2 and Comparative Example 4, showing excellent HER activity.

[0064] Fig.10 The LSV curve of the gallium-doped iridium-vanadium intermetallic compound supported on carbon prepared in Example 1 changes before and after ADT10000 cycles. It can be found that after ADT, the LSV curve of the catalyst is 10 mA cm -2 The overpotential at 200 nm decays by only 10 mV, demonstrating the excellent stability of the Ga-doped IrV-C-supported catalyst in OER.

[0065] Fig.11 The LSV curve of the gallium-doped iridium-vanadium intermetallic compound supported on carbon catalyst prepared in Example 1 changes before and after ADT 30000 cycles. It can be found that the two curves basically overlap before and after ADT, indicating the excellent stability of the gallium-doped iridium-vanadium intermetallic compound supported on carbon catalyst in HER.

[0066] As can be seen from the above examples, the alloy catalyst provided by the present invention is an iridium-based ordered intermetallic compound nanoparticle, which has very high activity and stability as a bifunctional catalyst for acidic water electrolysis OER and HER. The preparation method of the alloy catalyst provided by the present invention has a wide source of raw materials, a simple process, can be synthesized in large quantities, and has the potential for commercialization.

[0067] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a catalyst of a gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier, characterized in that: The method comprises the following preparation steps: (1) dispersing an iridium salt, a vanadium salt, a gallium salt and a carbon carrier in a solvent to obtain a mixture, wherein the molar ratio of iridium, vanadium and gallium atoms in the iridium salt, vanadium salt and gallium salt is 30:(8-9.5):(0.5-2); then heating the mixture to evaporate the solvent, vacuum drying the obtained sample and grinding it to obtain a precursor solid powder; (2) annealing the precursor solid powder in a reducing atmosphere to obtain a catalyst in which a gallium-doped iridium-vanadium intermetallic compound is supported on a carbon carrier.

2. The method for preparing a catalyst of a gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier according to claim 1, characterized in that: The annealing temperature rise rate is 3-10°C / min, the annealing temperature is 600-900°C, and the annealing time is 2-8h.

3. The method for preparing a catalyst of a gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier according to claim 1, characterized in that: The mass of the iridium atoms in the iridium salt accounts for 10-50% of the total mass of the iridium salt, the vanadium salt, the gallium salt and the carbon carrier.

4. The method for preparing a catalyst of a gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier according to claim 1, characterized in that: The iridium salt is one or more of chloroiridic acid, iridium acetylacetonate, and iridium acetate; the vanadium salt is one or more of vanadium trichloride, vanadium acetylacetonate, and vanadium acetate; the gallium salt is one or more of gallium nitrate, gallium acetate, and gallium acetylacetonate; the carbon carrier is one or more of carbon black, graphene, carbon nanotubes, and carbon nanowires.

5. The method for preparing a catalyst of a gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier according to claim 1, characterized in that: The reducing atmosphere is a mixed gas of hydrogen and argon, wherein the volume ratio of hydrogen is 5-10%; the solvent is one or both of water and ethanol.

6. The method for preparing a catalyst of a gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier according to claim 1, characterized in that: In step (1), ultrasound and stirring are also performed during the heating process; the ultrasound time is 0.5 to 2 hours, and the stirring speed is 300 to 500 rpm; in step (1), the heating temperature is 55° C. to 70° C.

7. A catalyst comprising a gallium-doped iridium-vanadium intermetallic compound prepared by the preparation method according to any one of claims 1 to 6 and supported on a carbon carrier.

8. The use of the catalyst of the gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier according to claim 7, characterized in that: It is used as a catalyst for preparing hydrogen and oxygen by electrolyzing water, wherein the electrolyzed water is selected from a sulfuric acid aqueous solution or a perchloric acid aqueous solution.

9. The use of the catalyst of the gallium-doped iridium-vanadium intermetallic compound supported on a carbon carrier according to claim 8, characterized in that: The concentrations of the sulfuric acid aqueous solution and the perchloric acid aqueous solution are both 0.1-0.5 mol / L.

Images