A ruthenium-based catalyst, its preparation method and application

Abstract

This invention relates to the field of catalyst technology, and more particularly to a ruthenium-based catalyst, its preparation method, and its applications. The invention provides a ruthenium-based catalyst comprising a porous carbon material and a ruthenium-containing substance dispersed on the surface and within the pore structure of the porous carbon material; the ruthenium-containing substance is monodispersed on the surface and within the pore structure of the porous carbon material; the porous carbon material is a nitrogen-doped porous carbon material or a nitrogen-sulfur co-doped porous carbon material. The ruthenium-based catalyst is low in cost and exhibits high activity and long-term stability.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a ruthenium-based catalyst, its preparation method, and its application. Background Technology

[0002] Human beings have mastered and utilized energy, achieving social progress and improved living standards. After the Second Industrial Revolution, fossil fuels occupied a crucial position in the energy structure. However, fossil fuels are natural, non-renewable resources. To meet the demands of human societal development for energy and a more livable environment, it is necessary to explore and utilize sustainable and clean energy sources. Hydrogen energy, with its abundant resources and cleanliness, is an energy source with enormous development potential. Utilizing hydrogen energy requires starting with hydrogen production, but natural sources of elemental hydrogen are extremely scarce, necessitating industrial acquisition. Currently, the vast majority of industrial hydrogen production relies on fossil fuel reforming, resulting in gray hydrogen (coal-to-hydrogen) and blue hydrogen (natural gas-to-hydrogen), processes often accompanied by carbon emissions. Simple water electrolysis at the cathode requires a high overpotential; using catalysts to lower the activation energy can significantly improve the reaction rate and hydrogen production efficiency. Currently, high-performance catalysts are typically commercial platinum-carbon catalysts, which are costly and require further improvement in stability. Summary of the Invention

[0003] The purpose of this invention is to provide a ruthenium-based catalyst, its preparation method, and its application. The ruthenium-based catalyst is low in cost and exhibits high activity and long-term stability.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] The present invention provides a ruthenium-based catalyst comprising a porous carbon material and a ruthenium-containing substance dispersed on the surface and within the pore structure of the porous carbon material;

[0006] The ruthenium-containing material is in a monodisperse state on the surface and within the pore structure of the porous carbon material;

[0007] The porous carbon material is a nitrogen-doped porous carbon material or a nitrogen-sulfur co-doped porous carbon material.

[0008] Preferably, the mass ratio of the porous carbon material to the ruthenium-containing substance is (85-95):(5-15).

[0009] Preferably, the porous substrate carbon material in the porous carbon material includes one or more of activated carbon, conductive carbon, graphite, graphene, and organic polymeric carbon materials.

[0010] Preferably, the ruthenium-containing material includes ruthenium nanoparticles or ruthenium sulfide nanoparticles.

[0011] Preferably, the particle size of the ruthenium-containing material is 1–3 nm.

[0012] This invention also provides a method for preparing the ruthenium-based catalyst described in the above technical solution, comprising the following steps:

[0013] Porous carbon materials, ruthenium salts, and polar solvents are mixed and subjected to a solvothermal reaction to obtain a carbon-based composite material containing ruthenium as a primary product.

[0014] The ruthenium-containing carbon-based composite material primary product is annealed to obtain the ruthenium-based catalyst.

[0015] Preferably, when the porous carbon material is a nitrogen-doped porous carbon material, the preparation process of the porous carbon material includes the following steps:

[0016] A porous carbon substrate material and a nitrogen source are mixed and subjected to a first solvothermal reaction to obtain the porous carbon material.

[0017] When the porous carbon material is a nitrogen-sulfur co-doped porous carbon material, the preparation process of the porous carbon material includes the following steps:

[0018] A nitrogen-doped porous carbon material is obtained by mixing a porous substrate carbon material with a nitrogen source and carrying out a second solvothermal reaction.

[0019] The nitrogen-doped porous carbon material, sulfur source, and water are mixed and subjected to a third solvothermal reaction to obtain a nitrogen-sulfur co-doped porous carbon material.

[0020] Preferably, the nitrogen source includes formamide and / or melamine;

[0021] The sulfur source includes one or more of thiourea, sodium sulfide, and thioacetamide.

[0022] Preferably, the temperatures of the solvothermal reaction, the first solvothermal reaction, and the second solvothermal reaction are independently 100–200°C, and the times are independently 1–24 h.

[0023] The annealing treatment is performed at a temperature of 200–1200℃ for a holding time of 0.5–5 hours.

[0024] The present invention also provides the application of the ruthenium-based catalyst described in the above technical solution or the ruthenium-based catalyst prepared by the preparation method described in the above technical solution in the electrolysis of water.

[0025] This invention provides a ruthenium-based catalyst, comprising a porous carbon material and a ruthenium-containing substance dispersed on the surface and within the pore structure of the porous carbon material; the ruthenium-containing substance is monodispersed on the surface and within the pore structure of the porous carbon material; the porous carbon material is a nitrogen-doped porous carbon material or a nitrogen-sulfur co-doped porous carbon material.

[0026] This invention enhances the chemical environment on the surface of porous carbon materials by doping and modifying them, and grows ruthenium-containing substances on the carbon support. This allows the ruthenium-containing substances and the porous carbon materials to work synergistically, promoting electron transfer between them and improving both the activity and stability of the catalyst. The supported ruthenium-containing substances are monodisperse, exposing a large number of active sites and improving the reactivity.

[0027] The ruthenium-based catalyst of this invention uses carbon materials as a substrate, which are widely available and inexpensive. The working electrode prepared from it exhibits superior performance under both acidic and alkaline working conditions.

[0028] This invention also provides a method for preparing the ruthenium-based catalyst described in the above technical solution, comprising the following steps: mixing porous carbon material, ruthenium salt, and a polar solvent, and carrying out a solvothermal reaction to obtain a ruthenium-containing carbon-based composite material primary product; annealing the ruthenium-containing carbon-based composite material primary product to obtain the ruthenium-based catalyst. The preparation method is relatively simple and easy to industrialize, providing an economical and simple synthetic route for the preparation of hydrogen evolution electrodes for water electrolysis cathodes. Attached Figure Description

[0029] Figure 1 The image shows a SEM image of the ruthenium-based catalyst described in Example 1.

[0030] Figure 2 The image shows a TEM image of the ruthenium-based catalyst described in Example 1.

[0031] Figure 3 The XRD pattern of the ruthenium-based catalyst described in Example 1;

[0032] Figure 4 The polarization curves (solid lines) of the ruthenium-based catalyst described in Example 1 in 0.5 mol / L H2SO4 solution (pH=0) and the polarization curves (dashed lines) of commercial platinum carbon in 0.5 mol / L H2SO4 solution (pH=0) are shown.

[0033] Figure 5 The polarization curves (solid lines) of the ruthenium-based catalyst described in Example 1 in 1.0 mol / L KOH solution (pH=14) and the polarization curves (dashed lines) of commercial platinum carbon in 1.0 mol / L KOH solution (pH=14) are shown.

[0034] Figure 6 The ruthenium-based catalyst described in Example 1 was used in a 0.5 mol / L H₂SO₄ solution (pH = 0) at 100 mA / cm⁻¹. 2 Stability curves at current densities;

[0035] Figure 7The ruthenium-based catalyst described in Example 1 was used in a 1.0 mol / L KOH solution (pH = 14) at 100 mA / cm². 2 Stability curves at current densities;

[0036] Figure 8 The image shows a SEM image of the ruthenium-based catalyst described in Example 2.

[0037] Figure 9 TEM image of the ruthenium-based catalyst described in Example 2;

[0038] Figure 10 The XRD pattern of the ruthenium-based catalyst described in Example 2;

[0039] Figure 11 The polarization curves (solid lines) of the ruthenium-based catalyst described in Example 2 in 0.5 mol / L H2SO4 solution (pH=0) and the polarization curves (dashed lines) of commercial platinum carbon in 0.5 mol / L H2SO4 solution (pH=0) are shown.

[0040] Figure 12 The polarization curves (solid lines) of the ruthenium-based catalyst described in Example 2 in 1.0 mol / L KOH solution (pH=14) and the polarization curves (dashed lines) of commercial platinum carbon in 1.0 mol / L KOH solution (pH=14) are shown.

[0041] Figure 13 The ruthenium-based catalyst described in Example 2 was used in a 0.5 mol / L H₂SO₄ solution (pH = 0) at 100 mA / cm⁻¹. 2 Stability curves at current densities;

[0042] Figure 14 The ruthenium-based catalyst described in Example 2 was used in a 1.0 mol / L KOH solution (pH = 14) at 100 mA / cm². 2 Stability curves at current densities;

[0043] Figure 15 The XPS spectrum of the ruthenium-based catalyst N1s described in Example 2;

[0044] Figure 16 The XPS spectrum of the ruthenium-based catalyst S2p described in Example 2 is shown below.

[0045] Figure 17The polarization curves (solid lines) of the ruthenium-based catalyst described in Example 2 in 0.5 mol / L H2SO4 solution (pH=0), the polarization curves (hollow circle dotted lines) of Comparative Example 1 in 0.5 mol / L H2SO4 solution (pH=0), the polarization curves (hollow triangle dotted lines) of Comparative Example 2 in 0.5 mol / L H2SO4 solution (pH=0), and the polarization curves (solid circle dotted lines) of Comparative Example 3 in 0.5 mol / L H2SO4 solution (pH=0);

[0046] Figure 18 The polarization curves (solid lines) of the ruthenium-based catalyst described in Example 2 in 1.0 mol / L KOH solution (pH=14), the polarization curves (hollow circle dotted lines) of Comparative Example 1 in 1.0 mol / L KOH solution (pH=14), the polarization curves (hollow triangle dotted lines) of Comparative Example 2 in 1.0 mol / L KOH solution (pH=14), and the polarization curves (solid circle dotted lines) of Comparative Example 3 in 1.0 mol / L KOH solution (pH=14). Detailed Implementation

[0047] The present invention provides a ruthenium-based catalyst comprising a porous carbon material and a ruthenium-containing substance dispersed on the surface and within the pore structure of the porous carbon material;

[0048] The ruthenium-containing material is in a monodisperse state on the surface and within the pore structure of the porous carbon material;

[0049] The porous carbon material is a nitrogen-doped porous carbon material or a nitrogen-sulfur co-doped porous carbon material.

[0050] In this invention, the porous substrate carbon material preferably includes one or more of activated carbon, conductive carbon, graphite, graphene, and organic polymeric carbon materials, and more preferably includes activated carbon. When the porous substrate carbon material is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0051] In this invention, the porosity of the porous carbon material is preferably 30% to 80%, more preferably 40% to 80%, and most preferably 50% to 80%. In this invention, the nitrogen doping content in the porous carbon material is preferably 20% to 30%, more preferably 22% to 28%, and most preferably 24% to 26%; the sulfur doping content in the porous carbon material is preferably 5% to 15%, more preferably 8% to 12%.

[0052] In this invention, the particle size of the ruthenium-containing material is preferably 1–3 nm. In this invention, the ruthenium-containing material preferably comprises ruthenium nanoparticles or ruthenium sulfide nanoparticles; more preferably, the ruthenium-containing material comprises elemental ruthenium.

[0053] In this invention, the preferred mass ratio of the porous carbon material to the ruthenium-containing substance is (80-90): (10-20), more preferably (82-88): (12-18), and most preferably (84-86): (13-16).

[0054] This invention also provides a method for preparing the ruthenium-based catalyst described in the above technical solution, comprising the following steps:

[0055] Porous carbon materials, ruthenium salts, and polar solvents are mixed and subjected to a solvothermal reaction to obtain a carbon-based composite material containing ruthenium as a primary product.

[0056] The ruthenium-containing carbon-based composite material primary product is annealed to obtain the ruthenium-based catalyst.

[0057] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.

[0058] This invention involves mixing porous carbon materials, ruthenium salts, and polar solvents, and then performing a solvothermal reaction to obtain a carbon-based composite material containing ruthenium.

[0059] In this invention, when the porous carbon material is a nitrogen-doped porous carbon material, the preparation process of the porous carbon material includes the following steps:

[0060] The porous carbon substrate material and a nitrogen source are mixed and subjected to a first solvothermal reaction to obtain the porous carbon material.

[0061] In this invention, the porous substrate carbon material preferably includes one or more of activated carbon, conductive carbon, graphite, graphene, and organic polymeric carbon materials, and more preferably includes activated carbon; when the porous substrate carbon material is two or more of the above-mentioned specific selections, this invention does not have any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0062] In this invention, the porosity of the porous substrate carbon material is preferably 30% to 80%, more preferably 40% to 80%, and most preferably 50% to 80%.

[0063] In this invention, the nitrogen source preferably includes formamide and / or melamine, more preferably formamide; the formamide can better functionalize the carbon substrate, and at the same time, formamide has its own pyrolytic reduction property, so strong reducing agents such as sodium borohydride are not required in the preparation of the ruthenium-based catalyst.

[0064] In this invention, the mass ratio of the porous substrate carbon material to the volume ratio of the nitrogen-containing solution is preferably 1 g:(30-40) mL, more preferably 1 g:(32-38) mL, and most preferably 1 g:(34-36) mL.

[0065] In this invention, the mixing is preferably carried out under ultrasonic conditions. This invention does not impose any special limitations on the ultrasonic process. A process well known to those skilled in the art can be used to ensure that the mixed solution is evenly dispersed.

[0066] In this invention, the temperature of the first solvothermal reaction is preferably 100-200°C, more preferably 120-180°C, and most preferably 140-160°C; the time is preferably 1-24 h, more preferably 5-20 h, and most preferably 10-15 h.

[0067] After the first solvothermal reaction is completed, the present invention preferably further includes sequential separation, washing, and drying; the present invention does not impose any special limitations on the separation, washing, and drying processes, and any process well known to those skilled in the art can be used. In the embodiments of the present invention, the separation method is specifically centrifugation.

[0068] When the porous carbon material is a nitrogen-sulfur co-doped porous carbon material, the preparation process of the porous carbon material includes the following steps:

[0069] A nitrogen-doped porous carbon material is obtained by mixing a porous substrate carbon material with a nitrogen source and carrying out a second solvothermal reaction.

[0070] The nitrogen-doped porous carbon material, sulfur source, and water are mixed and subjected to a third solvothermal reaction to obtain a nitrogen-sulfur co-doped porous carbon material.

[0071] In this invention, the sulfur source preferably includes thiourea.

[0072] In this invention, the preferred mass ratio of the nitrogen-doped porous carbon material, the sulfur source, and water is 60:10:7.

[0073] In this invention, the mixing of the nitrogen-doped porous carbon material, the sulfur source, and water is preferably carried out under ultrasonic conditions. This invention does not impose any special limitations on the ultrasonic process; any process well-known to those skilled in the art can be used. In this invention, the ultrasonic duration is 1 hour.

[0074] In this invention, the temperatures of the second and third solvothermal reactions are independently preferably 100–200°C, more preferably 120–180°C, and most preferably 140–160°C; the times are independently preferably 1–24 h, more preferably 5–20 h, and most preferably 10–15 h.

[0075] After the second or third solvothermal reaction is completed, the present invention preferably further includes sequential separation and drying; the present invention does not impose any special limitations on the separation and drying process, and any process well known to those skilled in the art can be used.

[0076] In this invention, the ruthenium salt is preferably a soluble ruthenium salt; the soluble ruthenium salt is preferably ruthenium chloride, ruthenium sulfate, or ruthenium nitrate.

[0077] In this invention, the polar solvent preferably includes water and / or alcoholic organic solvents; this invention does not impose any special limitation on the type of alcoholic organic solvent, and any type well known to those skilled in the art can be used.

[0078] In this invention, the mass ratio of the porous carbon material to the ruthenium salt is preferably 30:(2-6), more preferably 30:(3-5), and most preferably 30:4.

[0079] In this invention, the mass ratio of the porous carbon material to the volume ratio of the polar solvent is preferably 0.1-0.3 g:(35-40) mL, more preferably 1 g:(36-39) mL, and most preferably 1 g:(37-38) mL.

[0080] In this invention, the mixed raw materials preferably include a sulfur source; the sulfur source preferably includes one or more of thiourea, sodium sulfide and thioacetamide; when the sulfur source is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0081] In this invention, the mass ratio of the ruthenium salt to the sulfur source is preferably (2-5) mg:10 mg, more preferably (3-4) mg:10 mg.

[0082] In this invention, when the raw materials to be mixed are ruthenium salt, porous carbon material, and polar solvent, the mixing is preferably performed by first mixing the ruthenium salt and a portion of the polar solvent to obtain a ruthenium salt solution, and then secondly mixing the ruthenium salt solution, porous carbon material, and the remaining polar solvent. In this invention, the second mixing is preferably performed under ultrasonic conditions. This invention does not impose any special limitations on the ultrasonic process; any process well-known to those skilled in the art can be used. This invention does not impose any special limitations on the ratio of the partial polar solvent to the remaining polar solvent, as long as it ensures that the ruthenium salt is completely dispersed in the partial polar solvent.

[0083] In this invention, when the raw materials to be mixed are ruthenium salt, porous carbon material, sulfur source, and polar solvent, the mixing is preferably performed by third mixing of the ruthenium salt, sulfur source, and a portion of the polar solvent to obtain a mixture of ruthenium salt and sulfur source, followed by fourth mixing of the mixture of ruthenium salt and sulfur source, porous carbon material, and the remaining polar solvent. In this invention, the fourth mixing is preferably performed under ultrasonic conditions. This invention does not impose any special limitations on the ultrasonic process; any process well-known to those skilled in the art can be used. This invention does not impose any special limitations on the ratio of the partial polar solvent to the remaining polar solvent, as long as it ensures that the ruthenium salt and sulfur source are completely dispersed in the partial polar solvent.

[0084] In this invention, the temperature of the solvothermal reaction is preferably 100-200°C, more preferably 120-180°C, and most preferably 140-160°C; the time is preferably 1-24 h, more preferably 5-20 h, and most preferably 10-15 h.

[0085] After the solvothermal reaction is completed, the present invention preferably includes centrifugation, washing and drying in sequence; the present invention does not have any special limitations on the process of centrifugation, washing and drying, and any process known to those skilled in the art can be used.

[0086] After obtaining the ruthenium-containing carbon-based composite material primary product, the present invention anneales the ruthenium-containing carbon-based composite material primary product to obtain the ruthenium-based catalyst.

[0087] In this invention, the annealing treatment is preferably carried out in an argon atmosphere, and the annealing temperature is preferably 200–1200°C, more preferably 600–1100°C, and most preferably 800–1000°C. The heating rate to the annealing temperature is preferably 5–10°C / min, more preferably 6–9°C / min, and most preferably 7–8°C / min. The holding time for the annealing treatment is preferably 0.5–5 h, more preferably 1–4 h, and most preferably 2–3 h.

[0088] After the annealing process is completed, the present invention preferably includes cooling. The present invention does not have any special limitations on the cooling process, and any process known to those skilled in the art can be used.

[0089] This invention also provides the application of the ruthenium-based catalyst described in the above-described technical solutions or the ruthenium-based catalyst prepared by the preparation method described in the above-described technical solutions in water electrolysis. In this invention, the ruthenium-based catalyst is preferably prepared by obtaining a hydrogen evolution electrode for water electrolysis cathode and then applied to water electrolysis. This invention does not impose any special limitations on the specific process of the application; any process performed by those skilled in the art can be used.

[0090] The following detailed description of the ruthenium-based catalyst, its preparation method, and its application, with reference to specific embodiments, should not be construed as limiting the scope of protection of this invention.

[0091] Example 1

[0092] 1g of activated carbon powder (porosity 50%–80%, particle size 10nm–10μm) was mixed with 30mL of formamide, ultrasonically treated for 1h until uniformly dispersed, and then subjected to a solvothermal reaction (temperature 180℃, time 12h). After that, it was centrifuged, washed and dried in sequence to obtain nitrogen-doped activated carbon.

[0093] 100 mg of nitrogen-doped activated carbon, 1 mL of ruthenium trichloride aqueous solution with a concentration of 20 mg / mL and 35 mL of water were mixed and ultrasonically treated for 1 h until uniformly dispersed. After solvothermal reaction at 180 °C for 12 h, the mixture was centrifuged, washed and dried sequentially to obtain the initial product.

[0094] Under an argon atmosphere, the primary product was heated to 800°C at a heating rate of 10°C / min, held at that temperature for 2 hours, and then naturally cooled to obtain a ruthenium-based catalyst (comprising nitrogen-doped activated carbon and ruthenium; the mass ratio of the nitrogen-doped activated carbon to ruthenium was 90:10; the nitrogen doping amount in the nitrogen-doped activated carbon was 20%, the particle size of the ruthenium was 1–3 nm, and the porosity of the nitrogen-doped activated carbon was 50–80%).

[0095] Figure 1 Here is a SEM image of the ruthenium-based catalyst, from... Figure 1 It is known that the ruthenium-based catalyst has rich surface morphology and pore structure;

[0096] Figure 2 The TEM image of the ruthenium-based catalyst is shown below. Figure 2 It is known that the ruthenium in the ruthenium-based catalyst is mostly in a monodisperse state and is in the form of nanoparticles with a particle size of 1-3 nm;

[0097] Figure 3 The XRD pattern of the ruthenium-based catalyst is shown below. Figure 3 It can be seen that ruthenium was successfully loaded onto nitrogen-doped activated carbon in the ruthenium-based catalyst.

[0098] Example 2

[0099] 1g of activated carbon powder (porosity 50%–80%, particle size 10nm–10μm) was mixed with 30mL of formamide, ultrasonically treated for 1h until uniformly dispersed, and then subjected to a solvothermal reaction (temperature 180℃, time 12h). After that, it was centrifuged, washed and dried in sequence to obtain nitrogen-doped activated carbon.

[0100] 300 mg of nitrogen-doped activated carbon, 50 mg of thiourea and 35 mL of water were mixed and ultrasonically treated for 1 h until they were evenly dispersed. After a solvothermal reaction at 180 °C for 12 h, the mixture was centrifuged, washed and dried to obtain nitrogen-sulfur co-doped activated carbon.

[0101] 300 mg of nitrogen-sulfur co-doped activated carbon, 100 mg of thiourea, 1 mL of 20 mg / mL ruthenium trichloride aqueous solution and 35 mL of water were mixed and ultrasonically treated for 1 h until uniformly dispersed. After solvothermal reaction at 150 °C for 5 h, the mixture was centrifuged, washed and dried in sequence to obtain the initial product.

[0102] Under an argon atmosphere, the primary product was heated to 800°C at a heating rate of 10°C / min, held at that temperature for 2 hours, and then naturally cooled to obtain a ruthenium-based catalyst (comprising nitrogen-sulfur co-doped activated carbon and ruthenium sulfide; the mass ratio of the nitrogen-sulfur co-doped activated carbon to ruthenium sulfide was 90:10; the nitrogen doping amount in the nitrogen-sulfur co-doped activated carbon was 20%, the sulfur doping amount was 5%, the particle size of the ruthenium sulfide was 1–3 nm, and the porosity of the nitrogen-sulfur co-doped activated carbon was 50–80%).

[0103] Figure 8 Here is a SEM image of the ruthenium-based catalyst, from... Figure 8 It is known that the ruthenium-based catalyst has rich surface morphology and pore structure;

[0104] Figure 9 The TEM image of the ruthenium-based catalyst is shown below. Figure 9 It is known that the ruthenium in the ruthenium-based catalyst is mostly in a monodisperse state and is in the form of nanoparticles with a particle size of 1-3 nm;

[0105] Figure 10 The XRD pattern of the ruthenium-based catalyst is shown below. Figure 10 It can be seen that the characteristic diffraction peaks are not obvious, confirming that the ruthenium sulfide is uniformly dispersed, but the ruthenium sulfide loading is low;

[0106] Figure 15 The XPS spectrum of the ruthenium-based catalyst N1s is shown below. Figure 15 It can be seen that graphitic nitrogen, pyridine nitrogen, and pyrrole nitrogen are intended to illustrate the control of nitrogen sites, especially the strong interaction between pyridine nitrogen and pyrrole nitrogen and ruthenium;

[0107] Figure 16 The XPS spectrum of the ruthenium-based catalyst S2p is shown below. Figure 16 It can be seen that the XPS peaks of S2p include SC and -CSC, indicating that the control of sulfur sites is beneficial to the anchoring and interaction of ruthenium sulfide.

[0108] Comparative Example 1

[0109] 100 mg thiourea, 1 mL of 20 mg / mL ruthenium trichloride aqueous solution and 35 mL of water were mixed and ultrasonicated for 1 h until uniformly dispersed. After solvothermal reaction at 150 °C for 5 h, the mixture was centrifuged, washed and dried to obtain the initial product.

[0110] Under an argon atmosphere, the primary product was heated to 800°C at a heating rate of 10°C / min, held at that temperature for 2 hours, and then naturally cooled to obtain a comparative sample of the ruthenium-based catalyst without a carbon substrate.

[0111] Comparative Example 2

[0112] 1g of activated carbon powder (porosity 50%–80%, particle size 10nm–10μm) was mixed with 30mL of formamide, ultrasonically treated for 1h until uniformly dispersed, and then subjected to a solvothermal reaction (temperature 180℃, time 12h). After that, it was centrifuged, washed and dried in sequence to obtain nitrogen-doped activated carbon.

[0113] 300 mg of nitrogen-doped activated carbon, 50 mg of thiourea and 35 mL of water were mixed and ultrasonically treated for 1 h until they were evenly dispersed. After a solvothermal reaction at 180 °C for 12 h, the mixture was centrifuged, washed and dried to obtain nitrogen-sulfur co-doped activated carbon.

[0114] Under an argon atmosphere, the initial product was heated to 800°C at a heating rate of 10°C / min, held at that temperature for 2 hours, and then naturally cooled to obtain a separate nitrogen-sulfur co-doped activated carbon comparative sample.

[0115] The ruthenium-based catalyst without a carbon substrate obtained in Comparative Example 1 was physically mixed with a separate nitrogen-sulfur co-doped activated carbon to obtain a mixed comparative sample of the ruthenium-based catalyst without a carbon substrate and a separate nitrogen-sulfur co-doped activated carbon.

[0116] Comparative Example 3

[0117] 1g of activated carbon powder (porosity 50%–80%, particle size 10nm–10μm) was mixed with 30mL of formamide, ultrasonically treated for 1h until uniformly dispersed, and then subjected to a solvothermal reaction (temperature 180℃, time 12h). After that, it was centrifuged, washed and dried in sequence to obtain nitrogen-doped activated carbon.

[0118] 300 mg of nitrogen-doped activated carbon, 50 mg of thiourea and 35 mL of water were mixed and ultrasonically treated for 1 h until they were evenly dispersed. After a solvothermal reaction at 180 °C for 12 h, the mixture was centrifuged, washed and dried to obtain nitrogen-sulfur co-doped activated carbon.

[0119] Under an argon atmosphere, the primary product was heated to 800°C at a heating rate of 10°C / min, held at that temperature for 2 hours, and then naturally cooled to obtain a separate nitrogen-sulfur co-doped activated carbon comparative sample.

[0120] Test case

[0121] Using a calomel electrode as the reference electrode and a carbon electrode as the counter electrode, the working electrodes were prepared using the ruthenium-based catalysts obtained in Examples 1 and 2 and commercial platinum carbon. The electrolysis hydrogen evolution performance of the ruthenium-based catalysts and commercial platinum carbon described in this invention was tested using a three-electrode system and compared.

[0122] Figure 4 The polarization curves (solid line) of the ruthenium-based catalyst described in Example 1 in 0.5 mol / L H2SO4 solution (pH=0) and the polarization curves (dashed line) of commercial platinum-carbon in 0.5 mol / L H2SO4 solution (pH=0) are shown. Figure 5 The polarization curves (solid line) of the ruthenium-based catalyst described in Example 1 in 1.0 mol / L KOH solution (pH=14) and the polarization curves (dashed line) of commercial platinum-carbon in 1.0 mol / L KOH solution (pH=14) are shown below. Figures 4-5 It can be seen that the ruthenium-based catalyst prepared in Example 1 has excellent water electrolysis hydrogen evolution performance, which surpasses the water electrolysis hydrogen evolution performance of commercial platinum carbon.

[0123] Figure 11 The polarization curves (solid line) of the ruthenium-based catalyst described in Example 2 in 0.5 mol / L H2SO4 solution (pH=0) and the polarization curves (dashed line) of commercial platinum-carbon in 0.5 mol / L H2SO4 solution (pH=0) are shown. Figure 12 The polarization curves (solid line) of the ruthenium-based catalyst described in Example 2 in 1.0 mol / L KOH solution (pH=14) and the polarization curves (dashed line) of commercial platinum-carbon in 1.0 mol / L KOH solution (pH=14) are shown below. Figures 11-12 It can be seen that the ruthenium-based catalyst prepared in Example 2 has excellent water electrolysis hydrogen evolution performance, which is comparable to that of commercial platinum-carbon electrodes.

[0124] Figure 6 The ruthenium-based catalyst described in Example 1 was used in a 0.5 mol / L H₂SO₄ solution (pH = 0) at 100 mA / cm⁻¹. 2 Stability curves at current densities; Figure 7 The ruthenium-based catalyst described in Example 1 was used in a 1.0 mol / L KOH solution (pH = 14) at 100 mA / cm². 2 Stability curves at current densities; Figure 13 The ruthenium-based catalyst described in Example 2 was used in a 0.5 mol / L H₂SO₄ solution (pH = 0) at 100 mA / cm⁻¹. 2 Stability curves at current densities; Figure 14The ruthenium-based catalyst described in Example 2 was used in a 1.0 mol / L KOH solution (pH = 14) at 100 mA / cm². 2 Stability curves under current density; by Figures 6-7 or Figures 13-14 It is known that the ruthenium-based catalyst described in this invention operates at 100 mA / cm². 2 The voltage remained relatively stable for 24 hours at the specified current density without significant fluctuations. These data collectively demonstrate that the ruthenium-based catalyst described in this invention exhibits superior performance and stability in water electrolysis and hydrogen evolution.

[0125] Figure 17 The polarization curves (solid line) of the ruthenium-based catalyst described in Example 2 in 0.5 mol / L H₂SO₄ solution (pH=0), the polarization curve (hollow circle dotted line) of Comparative Example 1 in 0.5 mol / L H₂SO₄ solution (pH=0), the polarization curve (hollow triangle dotted line) of Comparative Example 2 in 0.5 mol / L H₂SO₄ solution (pH=0), and the polarization curve (solid circle dotted line) of Comparative Example 3 in 0.5 mol / L H₂SO₄ solution (pH=0) are shown below. Figure 17 It can be seen that the comparative samples of ruthenium-based catalyst without carbon substrate, the comparative samples of ruthenium-based catalyst without carbon substrate and nitrogen-sulfur co-doped activated carbon alone, and the comparative samples of nitrogen-sulfur co-doped activated carbon alone, all failed to achieve the performance of hydrogen evolution through water electrolysis in 0.5 mol / L H2SO4 solution (pH=0), indicating that the ruthenium-based metal and carbon substrate work synergistically.

[0126] Figure 18 The polarization curves (solid line) of the ruthenium-based catalyst described in Example 2 in 1.0 mol / L KOH solution (pH=14), the polarization curve (hollow circle dotted line) of Comparative Example 1 in 1.0 mol / L KOH solution (pH=14), the polarization curve (hollow triangle dotted line) of Comparative Example 2 in 1.0 mol / L KOH solution (pH=14), and the polarization curve (solid circle dotted line) of Comparative Example 3 in 1.0 mol / L KOH solution (pH=14) are shown below. Figure 18 It can be seen that the performance of the ruthenium-based catalyst alone without a carbon substrate, the ruthenium-based catalyst mixed with activated carbon alone without a carbon substrate, and the activated carbon alone without nitrogen and sulfur all failed to reach the performance of the ruthenium-based composite catalyst in the electrolysis of water in 1.0 mol / L KOH solution (pH=14), indicating that the ruthenium-based metal and the carbon substrate work synergistically.

[0127] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A ruthenium-based catalyst, characterized in that, Includes porous carbon materials and ruthenium-containing substances dispersed on the surface and within the pore structure of the porous carbon materials; The ruthenium-containing material is in a monodisperse state on the surface and within the pore structure of the porous carbon material; The porous carbon material is a nitrogen-doped porous carbon material or a nitrogen-sulfur co-doped porous carbon material; The nitrogen doping content in the porous carbon material is 20-30%; The particle size of the ruthenium-containing material is 1~3 nm; When the porous carbon material is a nitrogen-doped porous carbon material, the preparation process of the porous carbon material includes the following steps: A porous carbon substrate material and a nitrogen source are mixed and subjected to a first solvothermal reaction to obtain the porous carbon material. When the porous carbon material is a nitrogen-sulfur co-doped porous carbon material, the preparation process of the porous carbon material includes the following steps: A nitrogen-doped porous carbon material is obtained by mixing a porous substrate carbon material with a nitrogen source and carrying out a second solvothermal reaction. The nitrogen-doped porous carbon material, sulfur source and water are mixed and subjected to a third solvothermal reaction to obtain nitrogen-sulfur co-doped porous carbon material. The nitrogen source includes formamide; The temperatures of the first, second, and third solvothermal reactions are independently 100-200°C, and the times are independently 1-24 hours.

2. The ruthenium-based catalyst according to claim 1, characterized in that, The mass ratio of the porous carbon material to the ruthenium-containing substance is (80~90):(10~20).

3. The ruthenium-based catalyst according to claim 1 or 2, characterized in that, The porous carbon material includes one or more of the following: activated carbon, conductive carbon, graphite, graphene, and organic polymeric carbon materials.

4. The ruthenium-based catalyst according to claim 1 or 2, characterized in that, The ruthenium-containing material includes ruthenium nanoparticles or ruthenium sulfide nanoparticles.

5. The ruthenium-based catalyst according to claim 1, characterized in that, The sulfur source includes one or more of thiourea, sodium sulfide, and thioacetamide.

6. A method for preparing the ruthenium-based catalyst according to any one of claims 1 to 5, characterized in that, Includes the following steps: Porous carbon materials, ruthenium salts, and polar solvents are mixed and subjected to a solvothermal reaction to obtain a carbon-based composite material containing ruthenium as a primary product. The ruthenium-containing carbon-based composite material primary product is annealed to obtain the ruthenium-based catalyst.

7. The method as described in claim 6, characterized in that, The annealing process is carried out at a temperature of 200~1200℃ and a holding time of 0.5~5h.

8. The application of the ruthenium-based catalyst according to any one of claims 1 to 5 or the ruthenium-based catalyst prepared by the method according to claim 6 or 7 in the electrolysis of water.

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