Bimetallic catalyst for water electrolysis of oxygen and method of preparation

Abstract

The application discloses a kind of bimetallic catalysts and preparation method of water electrolytic oxygen reaction, the present application will Iridium chloride hydrate be dissolved in deionized water, by ultrasonic effect form transparent solution A;Sodium metavanadate is dissolved in standard oxalic acid solution, by ultrasonic effect form transparent solution B;Take the same amount of substance of sodium citrate and ethylenediaminetetraacetic acid disodium together in deionized water, by ultrasonic effect form transparent solution C, solution B and solution C are mixed by volume ratio, and composite transparent solution D is obtained;A, D solution is ultrasonically mixed, and transparent solution is obtained, heating reaction obtains brown product, the brown product is heat treated, and the final product is obtained after ultrasonic washing and vacuum drying;It is honeycomb vanadium / iridium bimetallic oxide, honeycomb vanadium / ruthenium bimetallic oxide or honeycomb vanadium / platinum bimetallic oxide.The catalyst preparation method described in the application is simple, easy to control, and conducive to actual production and application.

Description

Technical Field

[0001] This invention belongs to the field of water electrolysis catalysis technology, specifically relating to a catalyst for the oxygen evolution reaction of water electrolysis, and more particularly to a honeycomb bimetallic oxygen evolution reaction catalyst with high activity and durability in acidic environments and its preparation method. Background Technology

[0002] Hydrogen energy is a highly efficient and clean energy source. Currently, the most common method for industrial hydrogen production is water electrolysis, which is safe and environmentally friendly. The oxygen evolution reaction (OER) at the anode is one of the electrode reactions in the water electrolysis process. This reaction is slow, has a high OER potential, and requires high catalyst stability and stringent catalytic conditions, significantly limiting the development of the water electrolysis hydrogen production industry. Anode OER catalysts face significant challenges. The development of low-potential, highly active OER catalysts is crucial for improving the efficiency of water electrolysis hydrogen production.

[0003] Currently, anolyte oxygen evolution reaction (OER) catalysts mainly utilize noble metals such as Ir, Ru, and Pt, or their alloys and oxides, which possess oxygen evolution capabilities and corrosion resistance. However, noble metal catalysts are expensive, and composite catalysts incorporating non-noble metals are still rarely produced on a large scale. Therefore, low-cost, high-activity, stable, and corrosion-resistant anolyte catalysts are urgently needed in practical production.

[0004] According to previous research, bimetallic oxides formed by combining non-noble metals with similar atomic radii with noble metals such as Ir, Ru, and Pt are expected to achieve more efficient anodic oxygen evolution reaction performance through electronic structure adjustment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a bimetallic anode catalyst that exhibits high activity and low overpotential in the oxygen evolution reaction at the anode, strong corrosion resistance in acidic environments, and good overall stability.

[0006] A bimetallic catalyst for the water electrolysis oxygen release reaction, wherein the catalyst for the water electrolysis oxygen release reaction is a bimetallic nano-oxide.

[0007] Preferably, the bimetallic nanooxide is a honeycomb vanadium / iridium bimetallic oxide.

[0008] Preferably, the bimetallic nano-oxide is a sub-nano cluster with a particle size of less than 5 nm.

[0009] A method for preparing a bimetallic catalyst for the water electrolysis oxygen removal reaction, the method specifically includes the following steps:

[0010] Step 1: Dissolve iridium chloride hydrate at a concentration of 1–5 mol / L in deionized water and form a transparent solution A by sonication; dissolve sodium metavanadate at a concentration of 1–5 mol / L in a standard oxalic acid solution with a concentration of 0.1 mol / L and form a transparent solution B by sonication; dissolve equal amounts of sodium citrate and disodium ethylenediaminetetraacetate together in deionized water with a total molar concentration ratio of 0.5–2 mol / L and form a transparent solution C by sonication.

[0011] Step 2: Mix solutions B and C obtained in Step 1 by ultrasonication at a volume ratio of 1:2 to obtain a composite transparent solution D; then, mix solutions A and D by ultrasonication at a volume ratio of 1:3 for 20–30 minutes to obtain a transparent solution, and heat it at 100–200℃ for 1–3 hours to obtain a brownish-brown product.

[0012] Step 3: Heat-treat the brownish-red product obtained in Step 2. After ultrasonic washing and vacuum drying, the final product is a honeycomb vanadium / iridium bimetallic oxide.

[0013] Preferably, in step one, iridium chloride hydrate is replaced with ruthenium chloride hydrate or platinum chloride hydrate.

[0014] Preferably, the heat treatment of the brownish-brown product obtained in step two is specifically carried out at 250-450℃ for 1-3 hours.

[0015] As a preferred method, the vacuum drying conditions are: vacuum drying at 60-80℃ for 24-36 hours.

[0016] Preferably, the two metals in the honeycomb vanadium / iridium bimetallic oxide are evenly distributed, and the honeycomb structure has nanopores of less than 10 nm.

[0017] Preferably, the honeycomb vanadium / iridium bimetallic oxide is a sub-nano cluster with a particle size of less than 5 nm.

[0018] The overpotential of the bimetallic oxide nanocatalyst in the oxygen evolution reaction can be reduced by up to 30% compared to commercial anodic catalysts.

[0019] Beneficial effects:

[0020] 1. The catalyst proposed in this invention has a low overpotential in acidic environments, 10 mA / cm². 2 Under these conditions, the overpotential is as low as 238mV;

[0021] 2. The catalyst proposed in this invention exhibits strong stability in acidic environments, with a stability of 10 mA / cm². 2 Under certain conditions, it can last up to 130 hours.

[0022] 3. The catalyst preparation method described in this invention is simple, easy to control, and beneficial for practical production and application. Attached Figure Description

[0023] Figure 1 Microstructure of the vanadium / iridium bimetallic oxide catalyst prepared in Example 1;

[0024] Figure 2 The polarization curve of the anodic oxygen evolution reaction of the vanadium / iridium bimetallic oxide catalyst prepared in Example 1 with iridium oxide;

[0025] Figure 3 X-ray diffraction pattern of the vanadium / iridium bimetallic oxide catalyst prepared in Example 2;

[0026] Figure 4 The stability of the vanadium / ruthenium bimetallic oxide catalyst prepared in Example 3 was determined by chronopotential testing in 0.1 M HClO4;

[0027] Figure 5 Microstructure of the vanadium / ruthenium bimetallic oxide catalyst prepared in Example 3 after undergoing oxygen evolution reaction in 0.1M HClO4 for 130 h;

[0028] Figure 6 Microstructure of the vanadium / platinum bimetallic oxide catalyst prepared in Example 4. Detailed Implementation

[0029] Example 1

[0030] (1) Dissolve 20 mmol of iridium chloride hydrate completely in 10 mL of deionized water and sonicate to form solution A; dissolve 25 mmol of sodium metavanadate in 10 mL of oxalic acid solution and sonicate to form a transparent yellow solution B. The concentration of the oxalic acid solution is 0.1 mol / L; dissolve 15 mmol of sodium citrate and 15 mmol of disodium ethylenediaminetetraacetate in 20 mL of deionized water to form a transparent solution C.

[0031] (2) Mix 10 mL of solution B and 20 mL of solution C obtained in the above steps by ultrasonication to obtain 30 mL of transparent solution D; then, mix 10 mL of solution A and 30 mL of solution D by ultrasonication for 20 minutes to obtain a dark brown transparent solution, and heat it at 120°C for 2 hours to obtain a brownish product.

[0032] (3) The brown product obtained in the above steps was heat-treated at 400℃ for 2 hours. After ultrasonic washing, the product was vacuum dried at 60℃ for 24 hours. The final product was honeycomb vanadium / iridium bimetallic oxide.

[0033] The microstructure of the vanadium / iridium bimetallic oxide catalyst prepared in Example 1 is as follows: Figure 1As shown, it has a porous honeycomb structure with relatively uniform pore size.

[0034] A comparison of the polarization curves of the vanadium / iridium bimetallic oxide catalyst prepared in Example 1 with the anodic oxygen evolution reaction of iridium oxide is shown below. Figure 2 As shown, under the same conditions, the catalyst prepared in Example 1 has an overpotential of 238 mV, which is at least 10% lower than other catalysts, demonstrating superior anodic oxygen evolution performance.

[0035] Example 2

[0036] (1) Dissolve 20 mmol of iridium chloride hydrate completely in 10 mL of deionized water and sonicate to form solution A; dissolve 30 mmol of sodium metavanadate in 10 mL of oxalic acid solution and sonicate to form a transparent yellow solution B. The concentration of the oxalic acid solution is 0.1 mol / L; dissolve 10 mmol of sodium citrate and 10 mmol of disodium ethylenediaminetetraacetate in 20 mL of deionized water to form a transparent solution C.

[0037] (2) Mix 10 mL of solution B and 20 mL of solution C obtained in the above steps by ultrasonication to obtain 30 mL of transparent solution D; then, mix 10 mL of solution A and 30 mL of solution D by ultrasonication for 20 minutes to obtain a dark brown transparent solution, and heat it at 120°C for 2 hours to obtain a brownish product.

[0038] (3) The brown product obtained in the above steps was heat-treated at 400℃ for 2 hours. After ultrasonic washing, the product was vacuum dried at 60℃ for 24 hours. The final product was honeycomb vanadium / iridium bimetallic oxide.

[0039] The X-ray diffraction pattern of the vanadium / iridium bimetallic oxide catalyst prepared in Example 2 is as follows: Figure 3 As shown, the oxide exhibits good crystallinity, with its crystal structure primarily consisting of the cubic phase of iridium oxide.

[0040] Example 3

[0041] This embodiment is similar to Embodiment 1, except that in step (1), 20 mmol of ruthenium chloride hydrate is completely dissolved in 10 mL of deionized water and solution A is formed under ultrasonic treatment.

[0042] The stability of the vanadium / ruthenium bimetallic oxide catalyst prepared in Example 3, as determined by chronopotential testing in 0.1 M HClO4, is as follows: Figure 4 As shown, the duration is up to 130 hours, indicating strong corrosion resistance and good catalytic activity durability in acidic environments.

[0043] The microstructure of the vanadium / ruthenium bimetallic oxide catalyst prepared in Example 3 after oxygen evolution reaction in 0.1M HClO4 for 130 h is as follows. Figure 5 As shown, it still maintains a honeycomb nanostructure, indicating that the catalyst has good corrosion resistance in acidic environments.

[0044] Example 4

[0045] (1) Dissolve 30 mmol of platinum chloride completely in 10 mL of deionized water and sonicate to form solution A; dissolve 25 mmol of sodium metavanadate in 10 mL of oxalic acid solution and sonicate to form a transparent yellow solution B. The concentration of the oxalic acid solution is 0.1 mol / L; dissolve 20 mmol of sodium citrate and 20 mmol of disodium ethylenediaminetetraacetate in 20 mL of deionized water to form a transparent solution C.

[0046] (2) Mix 10 mL of solution B and 20 mL of solution C obtained in the above steps by ultrasonication to obtain 30 mL of transparent solution D; then, mix 10 mL of solution A and 30 mL of solution D by ultrasonication for 20 minutes to obtain a dark brown transparent solution, and heat it at 100°C for 3 hours to obtain a brownish product.

[0047] (3) The brownish-red product obtained in the above steps was heat-treated at 300℃ for 3 hours, and the resulting product was then ultrasonically washed. 7 Vacuum drying at 0℃ for 30 hours yielded a honeycomb-shaped vanadium / platinum bimetallic oxide, exhibiting good catalytic activity and durability. Figure 6 The microstructure of the prepared vanadium / platinum bimetallic oxide catalyst is shown.

[0048] Example 5

[0049] (1) Dissolve 20 mmol of ruthenium chloride completely in 10 mL of deionized water and sonicate to form solution A; dissolve 30 mmol of sodium metavanadate in 10 mL of oxalic acid solution and sonicate to form a transparent yellow solution B. The concentration of the oxalic acid solution is 0.1 mol / L; dissolve 10 mmol of sodium citrate and 10 mmol of disodium ethylenediaminetetraacetate in 20 mL of deionized water to form a transparent solution C.

[0050] (2) Mix 10 mL of solution B and 20 mL of solution C obtained in the above steps by ultrasonication to obtain 30 mL of transparent solution D; then, mix 10 mL of solution A and 30 mL of solution D by ultrasonication for 30 minutes to obtain a dark brown transparent solution, and heat it at 200°C for 1 hour to obtain a brownish product.

[0051] (3) The brown product obtained in the above steps was heat-treated at 450°C for 1 hour. After ultrasonic washing, the product was vacuum dried at 80°C for 24 hours. The final product was a honeycomb vanadium / ruthenium bimetallic oxide with good catalytic activity and durability.

Claims

1. A method for preparing a bimetallic catalyst for the water electrolysis oxygen reaction, characterized in that: The method specifically includes the following steps: Step 1: Dissolve iridium chloride hydrate at a concentration of 1–5 mol / L in deionized water and form a transparent solution A by sonication; dissolve sodium metavanadate at a concentration of 1–5 mol / L in a standard oxalic acid solution with a concentration of 0.1 mol / L and form a transparent solution B by sonication; dissolve equal amounts of sodium citrate and disodium ethylenediaminetetraacetate together in deionized water with a total molar concentration ratio of 0.5–2 mol / L and form a transparent solution C by sonication. Step 2: Mix solutions B and C obtained in Step 1 by ultrasonication at a volume ratio of 1:2 to obtain a composite transparent solution D; then, mix solutions A and D by ultrasonication at a volume ratio of 1:3 for 20–30 minutes to obtain a transparent solution, and heat it at 100–200℃ for 1–3 hours to obtain a brownish-brown product. Step 3: Heat-treat the brownish-red product obtained in Step 2. After ultrasonic washing and vacuum drying, the final product is a honeycomb vanadium / iridium bimetallic oxide.

2. The method for preparing a bimetallic catalyst for the water electrolysis oxygen reaction according to claim 1, characterized in that: The heat treatment of the brownish-brown product obtained in step two is specifically carried out at 250-450 ℃ for 1-3 hours.

3. The method for preparing a bimetallic catalyst for the water electrolysis oxygen reaction according to claim 1, characterized in that: The conditions for vacuum drying are: vacuum drying at 60-80 ℃ for 24-36 h.

4. The method for preparing a bimetallic catalyst for the water electrolysis oxygen reaction according to claim 1, characterized in that: The honeycomb vanadium / iridium bimetallic oxide has two metals evenly distributed and the honeycomb structure has nanopores of less than 10 nm.

5. A bimetallic catalyst for the water electrolysis oxygen reaction, characterized in that: The bimetallic catalyst for the water electrolysis oxygen reaction is prepared according to any one of claims 1 to 4.

6. The bimetallic catalyst for the water electrolysis oxygen reaction as described in claim 5, characterized in that: The bimetallic catalyst for the water electrolysis oxygen desorption reaction is a bimetallic nano-oxide, which is a sub-nano cluster with a particle size of less than 5 nm.

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