High-activity ruthenium-based hydrogen evolution catalyst material as well as preparation method and application thereof
The preparation of ruthenium-based hydrogen evolution catalyst on a conductive substrate by DC electrodeposition method solves the problems of high cost of precious metal catalysts and low reserves of platinum carbon catalysts in the prior art, and achieves high activity and low cost catalyst preparation, which improves the efficiency and application prospects of hydrogen production in electrolytic water.
Patent Information
- Application Number
- CN202510133804.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2025-05-30
AI Technical Summary
In the existing electrolytic hydrogen production technology, the commonly used high-efficiency catalysts contain precious metals such as Pt, Au, and Ag, which are costly. The platinum carbon catalyst has limited its application prospects in industrial hydrogen production due to the small reserves of metal platinum.
By direct current electrodeposition method, ruthenium salt, iron salt and citric acid are mixed in deionized water to form a solution and electroplating on a conductive substrate to prepare a highly active ruthenium-based hydrogen evolution catalyst material.
This method eliminates complex catalyst coating steps, the electroplating layer structure is stable and easy to control, and the cost is low. The prepared ruthenium-based catalyst exhibits hydrogen evolution properties better than or equivalent to commercial platinum carbon catalysts in basic and acidic solutions.
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Figure CN120060902A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of catalytic materials, and particularly relates to a ruthenium-based hydrogen evolution catalyst material with high activity, a preparation method and an application thereof, and specifically relates to a preparation method of a ruthenium-based hydrogen evolution catalyst and an application thereof in an electrolytic water hydrogen evolution reaction. Background Art
[0002] As a fuel with extremely high energy density, hydrogen is clean, environmentally friendly and pollution-free, and its combustion product has the advantage of zero emission, so it is considered to be the most promising alternative to fossil fuels.
[0003] The electrolytic water hydrogen production technology is simple to operate and can obtain high-purity hydrogen. In the electrolytic water hydrogen production technology, the catalyst plays a very important role. A catalyst with high catalytic activity can effectively improve the efficiency of electrolytic hydrogen production. At present, electrolytic water hydrogen production is usually carried out in acidic or alkaline solutions. Commonly used high-efficiency catalysts include Pt / CeO2–Co 7 Ni 2 Ox, Pd / PD-ZIF-67, Pt / 3DSiC, Pt 58 Ni 33 Au 9 , Pt / mesoporous silica, Ru@SiO 2 , Ni–Ru, Rh / Ni BNPs, Co 0.8 –Ag 0.2 –B, etc., which contain precious metals such as Pt, Au, Ag, etc., and the cost is relatively high. The platinum-carbon catalyst is currently recognized as an efficient and stable hydrogen production catalyst. However, the reserves of metallic platinum on the earth are scarce and the cost is high, which limits the application prospect of the platinum-carbon catalyst in industrial hydrogen production.
[0004] The ruthenium-based catalyst can achieve catalytic performance comparable to that of the platinum-based catalyst, but the price of metallic ruthenium is much lower than that of metallic platinum. At present, carbon-supported ruthenium-based catalysts are often prepared by high-temperature calcination in a protective or reducing atmosphere to avoid the agglomeration of ruthenium nanoparticles and improve the catalytic activity. However, high-temperature calcination often consumes more energy. Summary of the Invention
[0005] In order to improve the deficiencies of the prior art, the present invention provides a ruthenium-based catalyst material with high activity, a preparation method and an application thereof. By a simple direct current deposition method, the ruthenium-based catalyst is directly deposited on a conductive substrate, eliminating the complicated catalyst coating step. The catalyst prepared by the present invention has better hydrogen evolution performance than the commercial platinum-carbon catalyst in an alkaline solution and comparable hydrogen evolution performance to the commercial platinum-carbon catalyst in an acidic solution.
[0006] The present invention provides a preparation method of a ruthenium-based catalyst material, comprising the following steps:
[0007] (1) Mix ruthenium salt, iron salt, and citric acid evenly in deionized water to form a solution.
[0008] (2) Use a conductive substrate as the cathode and a carbon-based conductive material as the anode. Use the solution prepared in step (1) as the electroplating solution, and connect an external power supply to build an electroplating reaction cell.
[0009] (3) Apply a constant current density through an external DC power supply for electroplating; the electroplated cathode is the high-activity ruthenium-based hydrogen evolution catalyst material.
[0010] According to an embodiment of the present invention, the ruthenium salt in step (1) is at least one of ruthenium chloride, ruthenium acetate, and ruthenium bromide.
[0011] According to an embodiment of the present invention, the iron salt in step (1) is at least one of ferric chloride, ferrous chloride, ferric acetate, ferric nitrate, ferric sulfate, and ferrous sulfate.
[0012] According to an embodiment of the present invention, in the solution of step (1), the concentration of ruthenium ions is 0.01 mmol / L to 2 mol / L, preferably the concentration of ruthenium ions is 0.05 mmol / L to 1.5 mol / L, such as 0.1 mmol / L, 0.5 mmol / L, and 1 mmol / L.
[0013] According to an embodiment of the present invention, in the solution of step (1), the concentration of the iron ions is 0.01 mmol / L to 3 mol / L, preferably the concentration of the iron ions is 1 mmol / L to 2 mol / L, such as 0.03 mmol / L, 0.5 mol / L, 1 mmol / L, and 2 mmol / L.
[0014] According to an embodiment of the present invention, in the solution of step (1), the concentration of citric acid is 0.1 mmol / L to 4 mol / L, preferably the concentration of citric acid is 1 mmol / L to 2 mol / L, such as 1 mol / L, 3 mol / L, and 4 mol / L.
[0015] According to an embodiment of the present invention, in the solution of step (1), the molar ratio range of the ruthenium salt to the iron salt is 0.01 - 10; the molar amount ratio range of the metal salt to citric acid is 0.1 - 5.
[0016] According to an embodiment of the present invention, before step (2), it further includes pre-treating the conductive substrate used as the cathode, and the pre-treatment includes the following steps: first acid-treat the conductive substrate and then alkali-treat it.
[0017] According to an embodiment of the present invention, the acid treatment includes contacting the conductive substrate with an acid solution, such as by immersion; the alkali treatment includes contacting the conductive substrate with an alkali solution, such as by immersion.
[0018] According to an embodiment of the present invention, the acid solution is selected from sulfuric acid and / or hydrochloric acid with a concentration of 0.1 - 3 mol / L.
[0019] According to an embodiment of the present invention, the alkali solution is selected from sodium hydroxide and / or potassium hydroxide with a concentration of 0.1 - 3 mol / L.
[0020] According to an embodiment of the present invention, the cathode conductive substrate is selected from any one of conductive materials such as carbon paper, carbon felt, nickel foam, iron foam, titanium fiber, nickel foil, iron foil, and titanium foil.
[0021] According to an embodiment of the present invention, the carbon-based conductive material is selected from any one of graphite sheets, carbon paper, carbon felt, and carbon rods.
[0022] According to an embodiment of the present invention, the electrode area of the conductive substrate is 0.25 - 25 cm 2 , preferably 2 - 15 cm 2 .
[0023] According to an embodiment of the present invention, the anode is selected from any one of carbon-based conductive materials such as graphite rods and graphite sheets.
[0024] According to an embodiment of the present invention, the current density applied in step (3) is 0.001 - 2 A / cm 2 ; the electrolysis time is 5 - 120 min.
[0025] According to an embodiment of the present invention, in step (3), after electroplating, the following steps are further included: taking out the electroplated cathode, rinsing it thoroughly with deionized water and drying it to obtain a ruthenium-based hydrogen evolution catalyst electrode, that is, a ruthenium-based hydrogen evolution catalyst material.
[0026] In a second aspect, the present invention also provides a ruthenium-based catalyst material prepared by the above method, and the material includes a substrate, and a ruthenium-based catalyst is deposited on the substrate.
[0027] According to an embodiment of the present invention, the ruthenium-based catalyst adheres to the surface of the substrate in the structure of an electroplated layer, and the electroplated layer is dense and has a stable structure on the surface of the substrate.
[0028] According to an embodiment of the present invention, when the substrate is a fiber material, the ruthenium-based catalyst adheres to the fiber, for example, it is coated on the fiber in a ring shape or a semi-ring shape, or is randomly distributed in the gaps of the carbon paper fibers in a sheet shape.
[0029] According to an embodiment of the present invention, the ruthenium-based catalyst comprises a ruthenium element and an iron element. For example, the metal elements in the ruthenium-based catalyst are the ruthenium element and the iron element.
[0030] According to an embodiment of the present invention, in the ruthenium-based catalyst, the content of the ruthenium element is 0.1-10 wt%, and the content of the iron element is 0.1-20 wt%.
[0031] According to an embodiment of the present invention, the electrode has a SEM image substantially as Figure 1 shown.
[0032] According to an embodiment of the present invention, the ruthenium-based catalyst has an elemental distribution map substantially as Figure 2 shown.
[0033] In a third aspect, the present invention further provides an application of the above ruthenium-based catalyst material in hydrogen production, for example, as a catalyst for electrocatalytic water splitting to produce hydrogen.
[0034] In a fourth aspect, the present invention further provides an electrocatalytic water splitting hydrogen production device comprising the above ruthenium-based catalyst material.
[0035] Beneficial effects
[0036] 1. In the preparation method of the present invention, the reactants for preparing the ruthenium-based catalyst are used as raw materials. Through the direct current deposition method, the obtained ruthenium-based catalyst directly forms a dense electroplated layer deposited on the conductive substrate to form the ruthenium-based catalyst material. This not only omits the complex catalyst coating step, but also the structure of the electroplated layer is stable and uniform, and the combination with the conductive substrate is tight. At the same time, the method of the present invention has wide universality, easy condition control, easy operation, and can quickly and efficiently prepare the ruthenium-based catalyst in batches. Compared with the prior art that requires high-temperature calcination, the preparation method of the present invention has mild conditions and low cost.
[0037] 2. The elemental composition, content, ratio of the ruthenium-based catalyst prepared by the present invention are easy to adjust and the structure is controllable, and can be adjusted according to different requirements of catalytic reactions.
[0038] 3. The obtained ruthenium-based composite catalyst of the present invention exhibits excellent catalytic reaction performance and structural stability in alkaline and acidic electrocatalytic water splitting systems. For example, the ruthenium-based catalyst material prepared by the present invention has a hydrogen evolution performance exceeding that of commercial platinum-carbon in 1M KOH solution, and the overpotential corresponding to a current density of -200 mA / cm 2 is 103.7 mV, which is less than the overpotential of 119.7 mV required for the 40% Pt / C catalyst.
[0039] 4. The ruthenium-based catalyst material prepared by the present invention has potential application prospects in the field of electrolytic water hydrogen production. Description of the drawings
[0040] Figure 1 Scanning electron microscope morphology illustration diagrams of the ruthenium-based catalyst materials obtained in Example 1 at different magnifications.
[0041] Figure 2 Element distribution diagrams of O, Fe, and Ru of the ruthenium-based catalyst obtained in Example 1.
[0042] Figure 3 Performance comparison diagram of the electrode of the ruthenium-based catalyst prepared in Example 1 and the commercial catalyst platinum carbon in the hydrogen evolution reaction of alkaline electrolytic water.
[0043] Figure 4 Performance comparison diagram of the electrodes of the ruthenium-based catalysts prepared in Examples 2 - 10 and the commercial catalyst platinum carbon in the hydrogen evolution reaction of alkaline electrolytic water.
[0044] Figure 5 Performance comparison diagram of the electrode of the ruthenium-based catalyst prepared in Example 1 and the commercial catalyst platinum carbon in the hydrogen evolution reaction of acidic electrolytic water. Detailed implementation manners
[0045] The following will further elaborate on the catalyst materials of the present invention, their preparation methods, and applications in combination with specific examples. It should be understood that the following examples are only for illustrative and explanatory purposes of the present invention and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope intended to be protected by the present invention.
[0046] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.
[0047] The products of the following Examples 1 - 10 were detected by the following instruments and methods:
[0048] The morphology of the catalysts prepared in Examples 1 - 10 was characterized by scanning electron microscopy (SEM), and the structural composition information of the catalysts prepared in Examples 1 - 10 was characterized by energy dispersive spectroscopy (EDS) and inductively coupled plasma (ICP).
[0049] The hydrogen evolution performance of the catalysts prepared in Examples 1 - 10 was measured in alkaline and acidic electrocatalytic water splitting systems.
[0050] Examples 1 - 4 are examples of modulating the types and contents of ruthenium salts and iron salts; Examples 5 - 7 are examples of modulating the cathode and anode substrate materials of the electroplating cell; Examples 8 - 10 are examples of modulating the electroplating conditions.
[0051] Example 1
[0052] 1. Take 2.6 mg of RuCl 3 ·3H2 O, 1.2 mg of Fe(NO 3 ) 3 ·9H 2 O, 1.9 mg of citric acid were added to a beaker, and deionized water was slowly added to make the volume of the solution 100 mL, where the concentration of ruthenium chloride was 0.1 mmol / L, the concentration of iron nitrate was 0.03 mmol / L, and the concentration of citric acid was 0.1 mmol / L. Subsequently, it was stirred evenly with a glass rod to prepare a solution.
[0053] 2. The carbon paper was placed in dilute sulfuric acid with a concentration of 1 mol / L and soaked for 30 min, then placed in sodium hydroxide solution with a concentration of 1 mol / L and soaked for 30 min. After the carbon paper was rinsed clean, the treated carbon paper was used as the cathode, and the electroplating area was 3×3 cm 2 . A graphite rod was used as the anode, and the solution prepared in step 1 was used as the electroplating solution, and an external power supply was connected to build an electroplating reaction cell.
[0054] 3. At a current density of 600 mA cm -2 , electroplating was continued at room temperature for 30 min.
[0055] 4. The cathode was taken out, rinsed clean with deionized water and dried, and the electrode deposited with the ruthenium-based catalyst was obtained.
[0056] Figure 1 is the scanning electron microscope image of the ruthenium-based catalyst prepared in this example; it can be seen from Figure 1 that the ruthenium-based catalyst is firmly attached to the carbon paper fibers. Specifically, most of them are in a ring or semi-ring shape covering the carbon paper fibers, and a small amount are randomly distributed in the gaps between the carbon paper fibers in the form of flakes.
[0057] Figure 2 is the distribution map of O, Ru, and Fe elements in the ruthenium-based catalyst prepared in this example; it can be seen from Figure 2 that the distribution of ruthenium and iron elements in the ruthenium-based catalyst is relatively uniform.
[0058] As shown in Table 1, the mass percentage contents of ruthenium and iron in the ruthenium-based catalyst prepared in this example were tested by inductively coupled plasma (ICP) technology. Among them, the content of iron was 2.32 wt.%, and the content of ruthenium was 6.38 wt.%; Table 1 proved that only ruthenium and iron, two metal elements, were contained in the prepared catalyst.
[0059] Table 1 Mass percentage contents of ruthenium and iron in the ruthenium-based catalyst prepared in Example 1
[0060] Fe (wt.%) Ru (wt.%) 2.32 6.38
[0061] Example 2
[0062] 1. 13.9 mg of Ru(CH3 COO) 3 、27.0 mg of FeCl 3 ·3H 2 O, 38.4 mg of citric acid are added to a beaker, and deionized water is slowly added to make the solution volume 100 mL, where the ruthenium acetate concentration is 0.5 mmol / L, the ferric chloride concentration is 1 mmol / L, and the citric acid concentration is 2 mmol / L. Then, it is stirred evenly with a glass rod to prepare a solution.
[0063] 2. Place the carbon paper in dilute sulfuric acid with a concentration of 1 mol / L and soak for 30 min, then place it in sodium hydroxide solution with a concentration of 1 mol / L and soak for 30 min. After rinsing the carbon paper clean, use the treated carbon paper as the cathode, and the electroplating area is 3×3 cm 2 . Use a graphite rod as the anode, use the solution prepared in step 1 as the electroplating solution, and connect an external power supply to build an electroplating reaction cell.
[0064] 3. At a current density of 600 mA cm -2 , continuously electroplate at room temperature for 30 min.
[0065] 4. Take out the cathode, rinse it clean with deionized water and dry it, then the electrode deposited with the ruthenium-based catalyst is obtained.
[0066] Example 3
[0067] 1. Add 3.4 mg of RuBr 3 , 19.9 mg of Fe 2 (SO 4 ) 3 , 1.9 mg of citric acid to a beaker, and slowly add deionized water to make the solution volume 100 mL, where the ruthenium bromide concentration is 0.1 mol / L, the ferric sulfate concentration is 0.5 mol / L, and the citric acid concentration is 1 mol / L. Then, it is stirred evenly with a glass rod to prepare a solution.
[0068] 2. Place the carbon paper in dilute sulfuric acid with a concentration of 1 mol / L and soak for 30 min, then place it in sodium hydroxide solution with a concentration of 1 mol / L and soak for 30 min. After rinsing the carbon paper clean, use the treated carbon paper as the cathode, and the electroplating area is 3×3 cm 2 . Use a graphite rod as the anode, use the solution prepared in step 1 as the electroplating solution, and connect an external power supply to build an electroplating reaction cell.
[0069] 3. At a current density of 600 mA cm -2 , continuously electroplate at room temperature for 30 min.
[0070] 4. Take out the cathode, rinse it clean with deionized water and dry it, then the electrode deposited with the ruthenium-based catalyst is obtained.
[0071] Example 4
[0072] 1. Add 2.6145 g of RuCl 3 ·3H 2 O, 2.535 g of FeCl 2 , and 7.6848 g of citric acid into a beaker. Slowly add deionized water to make the volume of the solution 100 mL, where the concentration of ruthenium chloride is 0.1 mol / L, the concentration of ferrous chloride is 0.2 mol / L, and the concentration of citric acid is 0.4 mol / L. Then stir evenly with a glass rod to prepare a solution.
[0073] 2. Immerse the carbon paper in dilute sulfuric acid with a concentration of 1 mol / L for 30 min, and then immerse it in sodium hydroxide solution with a concentration of 1 mol / L for 30 min. After rinsing the carbon paper clean, use the treated carbon paper as the cathode, and the electroplating area is 3×3 cm 2 . Use a graphite rod as the anode, use the solution prepared in step 1 as the electroplating solution, and connect an external power supply to build an electroplating reaction cell.
[0074] 3. At a current density of 600 mA cm -2 , continuously electroplate at room temperature for 30 min.
[0075] 4. Take out the cathode, rinse it clean with deionized water and dry it to obtain an electrode deposited with a ruthenium-based catalyst.
[0076] The above Examples 1-4 are examples of modulating the types and contents of ruthenium salts and iron salts, indicating that under the regulation of a single variable, by changing the types and contents of each component, the corresponding ruthenium-based catalysts can be prepared, that is, the preparation method designed in the present invention can be applied to the preparation of various ruthenium-based materials, and its hydrogen evolution reaction performance is verified and described in the application examples.
[0077] Example 5
[0078] 1. Add 0.26145 g of RuCl 3 ·3H 2 O, 6.0598 g of Fe(NO 3 ) 3 ·9H 2 O, and 5.7636 g of citric acid into a beaker. Slowly add deionized water to make the volume of the solution 100 mL, where the concentration of ruthenium chloride is 0.01 mol / L, the concentration of iron nitrate is 1.5 mol / L, and the concentration of citric acid is 3 mol / L. Then stir evenly with a glass rod to prepare a solution.
[0079] 2. Immerse the titanium foam in dilute sulfuric acid with a concentration of 1 mol / L for 30 min, then immerse it in sodium hydroxide solution with a concentration of 1 mol / L for 30 min. After rinsing the titanium foam clean, use the treated titanium foam as the cathode, and the electroplating area is 2×2 cm 2 . Use a graphite rod as the anode, use the solution prepared in step 1 as the electroplating solution, and connect an external power supply to build an electroplating reaction cell.
[0080] 3. At a current density of 200 mA cm -2 , continuously electroplate at room temperature for 40 min.
[0081] 4. Take out the cathode, rinse it clean with deionized water and dry it, then the electrode deposited with the ruthenium-based catalyst is obtained.
[0082] Example 6
[0083] 1. Add 0.26145 g of RuCl 3 ·3H 2 O, 6.0598 g of Fe(NO 3 ) 3 ·9H 2 O, and 5.7636 g of citric acid into a beaker, slowly add deionized water to make the volume of the solution 100 mL, where the concentration of ruthenium chloride is 0.01 mol / L, the concentration of iron nitrate is 1.5 mol / L, and the concentration of citric acid is 3 mol / L. Then stir evenly with a glass rod to prepare a solution.
[0084] 2. Immerse the carbon paper in dilute sulfuric acid with a concentration of 1 mol / L for 30 min, then immerse it in sodium hydroxide solution with a concentration of 1 mol / L for 30 min. After rinsing the carbon paper clean, use the treated carbon paper as the cathode, and the electroplating area is 1×1 cm 2 . Use a graphite sheet as the anode, use the solution prepared in step 1 as the electroplating solution, and connect an external power supply to build an electroplating reaction cell.
[0085] 3. At a current density of 200 mA cm -2 , continuously electroplate at room temperature for 40 min.
[0086] 4. Take out the cathode, rinse it clean with deionized water and dry it, then the electrode deposited with the ruthenium-based catalyst is obtained.
[0087] Example 7
[0088] 1. Add 0.26145 g of RuCl 3 ·3H 2 O, 6.0598 g of Fe(NO 3 ) 3 ·9H 25.7636 g of citric acid was added to a beaker, and deionized water was slowly added to make the solution volume 100 mL, where the ruthenium chloride concentration was 0.01 mol / L, the iron nitrate concentration was 1.5 mol / L, and the citric acid concentration was 3 mol / L. Subsequently, it was stirred evenly with a glass rod to prepare a solution.
[0089] 2. The nickel foam was placed in dilute sulfuric acid with a concentration of 1 mol / L and soaked for 30 min, then placed in a sodium hydroxide solution with a concentration of 1 mol / L and soaked for 30 min. After the nickel sheet was rinsed clean, the treated nickel foam was used as the cathode, and the electroplating area was 4×4 cm 2 . Carbon felt was used as the anode, and the solution prepared in step 1 was used as the electroplating solution. An external power supply was connected to build an electroplating reaction cell;
[0090] 3. At a current density of 200 mA cm -2 , electroplating was continued at room temperature for 40 min;
[0091] 4. The cathode was taken out, rinsed clean with deionized water and dried, and the electrode deposited with the ruthenium-based catalyst was obtained.
[0092] In the above Examples 5-7, the materials and sizes of the cathode and anode conductive substrates were modulated, indicating that under the regulation of a single variable, by changing the materials and sizes of the cathode and anode, the corresponding ruthenium-based catalysts could be prepared. That is, the preparation method designed in the present invention can be applied to the preparation of various ruthenium-based materials, and its hydrogen evolution reaction performance was verified and described in the application examples.
[0093] Example 8
[0094] 1. 5.229 g of RuCl 3 ·3H 2 O, 40.399 g of Fe(NO 3 ) 3 ·9H 2 O, 38.424 g of citric acid was added to a beaker, and deionized water was slowly added to make the solution volume 100 mL, where the ruthenium chloride concentration was 0.2 mol / L, the iron nitrate concentration was 1 mol / L, and the citric acid concentration was 2 mol / L. Subsequently, it was stirred evenly with a glass rod to prepare a solution.
[0095] 2. The carbon paper was placed in dilute sulfuric acid with a concentration of 1 mol / L and soaked for 30 min, then placed in a sodium hydroxide solution with a concentration of 1 mol / L and soaked for 30 min. After the carbon paper was rinsed clean, the treated carbon paper was used as the cathode, and the electroplating area was 1×1 cm 2 . A graphite rod was used as the anode, and the solution prepared in step 1 was used as the electroplating solution. An external power supply was connected to build an electroplating reaction cell;
[0096] 3. At a current density of 100 mA cm -2 , electroplate continuously at room temperature for 60 min;
[0097] 4. Take out the cathode, rinse it thoroughly with deionized water and dry it, then an electrode deposited with a ruthenium-based catalyst is obtained.
[0098] Example 9
[0099] 1. Add 5.229 g of RuCl 3 ·3H 2 O, 40.399 g of Fe(NO 3 ) 3 ·9H 2 O, and 38.424 g of citric acid into a beaker, slowly add deionized water to make the solution volume 100 mL, where the ruthenium chloride concentration is 0.2 mol / L, the iron nitrate concentration is 1 mol / L, and the citric acid concentration is 2 mol / L. Then stir evenly with a glass rod to prepare a solution.
[0100] 2. Immerse the carbon paper in dilute sulfuric acid with a concentration of 1 mol / L for 30 min, then immerse it in a sodium hydroxide solution with a concentration of 1 mol / L for 30 min. After rinsing the carbon paper thoroughly, use the treated carbon paper as the cathode, and the electroplating area is 1×1 cm 2 . Use a graphite rod as the anode, prepare the solution as the electroplating solution, connect an external power supply to build an electroplating reaction cell;
[0101] 3. At a current density of 300 mA cm -2 , electroplate continuously at room temperature for 20 min;
[0102] 4. Take out the cathode, rinse it thoroughly with deionized water and dry it, then an electrode deposited with a ruthenium-based catalyst is obtained.
[0103] Example 10
[0104] 1. Add 5.229 g of RuCl 3 ·3H 2 O, 40.399 g of Fe(NO 3 ) 3 ·9H 2 O, and 38.424 g of citric acid into a beaker, slowly add deionized water to make the solution volume 100 mL, where the ruthenium chloride concentration is 0.2 mol / L, the iron nitrate concentration is 1 mol / L, and the citric acid concentration is 2 mol / L. Then stir evenly with a glass rod to prepare a solution.
[0105] 2. Place the carbon paper in dilute sulfuric acid with a concentration of 1 mol / L and soak for 30 min, then place it in sodium hydroxide solution with a concentration of 1 mol / L and soak for 30 min. After rinsing the carbon paper clean, use the treated carbon paper as the cathode, and the electroplating area is 1×1 cm 2 . Use a graphite rod as the anode, use the solution prepared in step 1 as the electroplating solution, connect an external power supply to build an electroplating reaction cell;
[0106] 3. At a current density of 1 A cm -2 , continuously electroplate at room temperature for 10 min;
[0107] 4. Take out the cathode, rinse it clean with deionized water and dry it, then an electrode deposited with a ruthenium-based catalyst is obtained.
[0108] The above Examples 8-10 are the modulation of the current density and time of electroplating, indicating that under the control of a single variable, by changing the current density and time during electroplating, the corresponding ruthenium-based catalysts can be prepared. That is, the preparation method designed in the present invention can be applied to the preparation of various ruthenium-based catalysts, and its hydrogen evolution reaction performance is verified and explained in the application examples.
[0109] Application Example 1
[0110] Respectively use the ruthenium-based catalysts prepared in the above Examples 1-10 and the 40% commercial platinum-carbon catalyst produced by Johnson Matthey as the hydrogen evolution reaction catalysts in the alkaline electrolyzed water system to prove the application potential of the ruthenium-based catalyst in the present invention.
[0111] 1. Prepare a commercial platinum-carbon catalyst electrode: Weigh 3 mg of 40% platinum-carbon catalyst, add it to a solution containing 200 μL of water and 290 μL of ethanol solution, then add 10 μL of 5% Nafion solution by mass fraction, and ultrasonicate for 30 minutes; after the catalyst is evenly dispersed, suck 30 μL of the solution and drop it on a carbon paper with a working area of 0.25×0.25 cm 2 for hydrogen evolution performance testing as a control.
[0112] 2. Set up the test system: The test device is a three-electrode system. The reference electrode is Hg / HgO, the counter electrode is a carbon rod, and the working electrode is a carbon paper electrode deposited with the ruthenium-based catalyst prepared in Examples 1-10 or the commercial platinum-carbon catalyst electrode prepared in step 1. The electrolyte is 1 M KOH solution, and a 50 mL single-cell electrolytic cell is used during the test.
[0113] 3. Catalytic performance evaluation method: Keep the temperature of the electrolytic cell at room temperature, evaluate the hydrogen evolution performance of the catalyst through polarization curves, and compare the current densities of the ruthenium-based catalyst and the platinum-carbon catalyst at the same potential. The specific test results Figure 3 and Figure 4 are shown as follows.
[0114] It can be seen from Figure 3 that when the ruthenium-based catalyst prepared in Example 1 reaches a current density of -200 mA / cm 2 , the overpotential is only 103.7 mV, which is less than the overpotential (119.7 mV) required for the 40% Pt / C catalyst. Thus, it can be known that the ruthenium-based catalyst prepared in Example 1 exhibits excellent hydrogen evolution activity.
[0115] It can be seen from Figure 4 that the ruthenium-based catalysts prepared in Examples 2-10 have hydrogen evolution performance exceeding or comparable to that of commercial platinum carbon in 1 M KOH solution.
[0116] Application Example 2
[0117] The ruthenium-based catalyst prepared in Example 1 above and the 40% commercial platinum carbon catalyst produced by Johnson Matthey were respectively used as the hydrogen evolution reaction catalysts in the acidic electrolyzed water system to prove the application potential of the ruthenium-based catalyst.
[0118] 1. Preparation of the commercial platinum carbon catalyst electrode: Weigh 3 mg of the 40% platinum carbon catalyst, add it to a solution containing 200 μL of water and 290 μL of ethanol solution, and then add 10 μL of a 5% Nafion solution by mass. Ultrasonic for 30 minutes; after the catalyst is evenly dispersed, suck 30 μL of the solution and drop it on the carbon paper with a working area of 0.25×0.25 cm 2 as a control for hydrogen evolution performance testing.
[0119] 2. Setup of the test system: The test device is a three-electrode system. The reference electrode is Hg / Hg 2 SO 4 , the counter electrode is a carbon rod, and the working electrode is the carbon paper electrode deposited with the ruthenium-based catalyst prepared in Example 1 or the commercial platinum carbon catalyst. The electrolyte is 0.5 M H 2 SO 4 solution. A 50 mL single-cell electrolytic cell is used during the test.
[0120] 3. Catalytic performance evaluation method: The temperature of the electrolytic cell is maintained at room temperature, and the hydrogen evolution performance of the catalyst is evaluated through polarization curves. The current densities of the ruthenium-based catalyst and the platinum carbon catalyst at the same potential are compared. The specific test results Figure 5 are shown as follows.
[0121] It can be seen from Figure 5 that when the ruthenium-based catalyst prepared in Example 1 reaches a current density of -200 mA / cm 2The overpotential corresponding to the current density of [X] is 131.6 mV, which is close to the overpotential (94.5 mV) required for the 40% Pt / C catalyst, indicating that the ruthenium-based catalyst prepared in Example 1 still has good hydrogen evolution performance under acidic conditions.
[0122] The specific embodiments of the present invention have been exemplarily described above through examples. However, the protection scope of the present invention is not limited to the above exemplary embodiments. Any modifications, equivalent replacements, improvements, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.
Claims
1. A method for preparing a ruthenium-based catalyst material, characterized in that: The method comprises the following steps: (1) adding ruthenium salt, iron salt and citric acid into deionized water and mixing them evenly to prepare a solution; (2) using a conductive substrate as a cathode, a carbon-based conductive material as an anode, and the solution prepared in step (1) as an electroplating solution, and connecting an external power supply to build an electroplating reaction cell; (3) Electroplating is performed by applying a constant current density through an external DC power supply; the cathode after electroplating is a highly active ruthenium-based hydrogen evolution catalyst material.
2. The method for preparing a ruthenium-based catalyst material according to claim 1, characterized in that: In step (1), the molar ratio of the ruthenium salt to the iron salt is in the range of 0.01-10; the molar ratio of the sum of the ruthenium salt and the iron salt to citric acid is in the range of 0.1-5.
3. The method for preparing a ruthenium-based catalyst material according to claim 1, characterized in that: The ruthenium salt in step (1) is at least one of ruthenium chloride, ruthenium acetate, and ruthenium bromide; the iron salt in step (1) is at least one of ferric chloride, ferrous chloride, ferric acetate, ferric nitrate, ferric sulfate, and ferrous sulfate.
4. The method for preparing a ruthenium-based catalyst material according to any one of claims 1 to 3, characterized in that: In the solution of step (1), the concentration of ruthenium ions is 0.01mmol / L to 2mol / L, the concentration of iron ions is 0.01mmol / L to 3mol / L, and the concentration of citric acid is 0.1mmol / L to 4mol / L.
5. The method for preparing a ruthenium-based catalyst material according to any one of claims 1 to 3, characterized in that: The cathode conductive substrate is selected from any one of conductive materials such as carbon paper, carbon felt, foamed nickel, foamed iron, titanium fiber, nickel foil, iron foil, titanium foil, etc. Preferably, the carbon-based conductive material is selected from any one of graphite sheets, carbon paper, carbon felt and carbon rods. Preferably, the anode is selected from any one of carbon-based conductive materials such as graphite rods and graphite sheets.
6. The method for preparing a ruthenium-based catalyst material according to any one of claims 1 to 3, characterized in that: The current density applied in step (3) is 0.001 to 2 A / cm 2 ; The electrolysis time is 5 to 120 minutes.
7. A ruthenium-based catalyst electrode material prepared by the method according to any one of claims 1 to 6, characterized in that: The material comprises a substrate, a ruthenium-based catalyst is deposited on the substrate, and the ruthenium-based catalyst is attached to the surface of the substrate in the structure of an electroplating layer.
8. The ruthenium-based catalyst electrode material according to claim 7, characterized in that The ruthenium-based catalyst comprises ruthenium element and iron element. In the ruthenium-based catalyst, the content of the ruthenium element is 0.1-10 wt %, and the content of the iron element is 0.1-20 wt %.
9. Use of a ruthenium-based catalyst material prepared by the method according to any one of claims 1 to 6 or a ruthenium-based catalyst material according to any one of claims 7 to 8 in hydrogen production, for example, as a catalyst for producing hydrogen by electrocatalytic decomposition of water.
10. An electrocatalytic water decomposition hydrogen production device, comprising the ruthenium-based catalyst material prepared by the method according to any one of claims 1 to 6 or the ruthenium-based catalyst material according to any one of claims 7 to 8.