A ruthenium-iridium supported porous carbon nanofiber material, preparation and application thereof

Abstract

This invention relates to a ruthenium-iridium supported porous carbon nanofiber material and its preparation and application. The preparation method includes the following steps: (1) adding polyvinylpyrrolidone and betaine to water and stirring to obtain a uniformly dispersed mixed solution; (2) preparing polyvinylpyrrolidone / betaine nanofibers by electrospinning the mixed solution; (3) immersing the polyvinylpyrrolidone / betaine nanofibers in a ruthenium chloride / iridium chloride solution and hydrothermally obtaining ruthenium chloride / iridium chloride porous polyvinylpyrrolidone nanofibers; (4) placing the ruthenium chloride / iridium chloride porous polyvinylpyrrolidone nanofibers under an inert gas protection environment, heating and carbonizing, and cooling to obtain the target product. Compared with the prior art, the nanofiber material of this invention is beneficial to improving the active sites of composite materials and can be applied to the chlorine evolution reaction in the ion-exchange membrane chlor-alkali industry of pesticide waste salt.

Description

Technical Field

[0001] This invention relates to the field of composite materials technology, and in particular to a ruthenium-iridium supported porous carbon nanofiber material and its preparation and application. Background Technology

[0002] The chlor-alkali industry is a crucial component of the basic chemical industry, with one of its core reactions being the anodic chlorine evolution reaction, which is essential for the production of chlorine, sodium hydroxide, and hydrogen. Traditional chlorine evolution reaction catalysts primarily employ ruthenium-titanium coated anodes (DSA), which exhibit good activity and stability under standard conditions. However, with increasingly stringent environmental regulations and growing demands for industrial waste resource utilization, the treatment and recycling of complex industrial by-product salts, especially waste salts generated during the production of highly toxic and recalcitrant pesticides, has become a pressing industry challenge.

[0003] Pesticide waste salts typically contain residual pesticide molecules, intermediates, heavy metal ions, and other organic and inorganic impurities. These impurities readily adsorb onto the active sites of traditional catalysts during electrolysis, leading to catalyst poisoning, deactivation, and a significant shortening of their lifespan. Furthermore, the presence of impurities alters the overpotential of the electrolysis process, increasing energy consumption and potentially triggering competitive oxygen evolution reactions, thus reducing current efficiency and the purity of the target product, chlorine. Therefore, developing a chlorine evolution reaction catalyst that can adapt to complex systems, possesses high resistance to poisoning, and exhibits excellent stability is of great significance for realizing the high-value resource utilization of pesticide waste salts and promoting the green and sustainable development of the chlor-alkali industry.

[0004] Patent application CN111001426B discloses a ruthenium single-atom catalyst for the chlor-alkali industry anode and its preparation method. This catalyst is prepared by dispersing ruthenium in single-atom form on a substrate, achieving chlorine evolution reaction at ultra-high current density with an overpotential far lower than that of industrial DSA electrodes; it achieves 100% selectivity and excellent stability for the chlorine evolution reaction. However, the TiN support used in this invention has a relatively small specific surface area and lacks a hierarchical pore structure, resulting in relatively poor conductivity. Furthermore, single-atom catalysts typically require extremely low metal loading, which may lead to insufficient absolute active site density in the overall electrode, limiting the total current output per unit area of ​​catalyst.

[0005] Porous carbon nanofibers are considered an ideal catalyst support due to their high specific surface area, excellent electrical conductivity, and tunable structure. However, how to construct highly active and stable metal centers on them and enable them to perform optimally in the harsh electrolysis environment of pesticide waste salts remains a challenge for current technology. Summary of the Invention

[0006] The purpose of this invention is to provide a ruthenium-iridium supported porous carbon nanofiber material, its preparation and application, so as to improve its activity as a chlorine evolution catalyst in the chlor-alkali industry.

[0007] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a method for preparing ruthenium-iridium supported porous carbon nanofiber materials, comprising the following steps: S1. Polyvinylpyrrolidone and betaine are immersed in a solvent and stirred to obtain a uniformly dispersed spinning precursor solution. Then, polyvinylpyrrolidone / betaine nanofibers are obtained by electrospinning. S2. The polyvinylpyrrolidone / betaine nanofibers obtained in S1 are immersed in a mixed solution of ruthenium chloride and iridium chloride and subjected to hydrothermal reaction to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers. S3. The ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers obtained in S2 are placed under inert gas protection, heated and carbonized, and then cooled to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0008] Furthermore, the solvent in S1 is water.

[0009] Furthermore, in S1, the mass ratio of polyvinylpyrrolidone to betaine is 2-4:1, and polyvinylpyrrolidone and betaine account for 10-20 wt% of the total weight of the spinning precursor solution.

[0010] Furthermore, in S1, the specific process conditions for electrospinning are as follows: the ejection speed is 0.4 mL / h to 0.7 mL / h, the spinning voltage is 8 to 18 kV, and the distance from the spinning nozzle to the receiver is 14 to 18 cm. Additionally, after electrospinning, the resulting fibers are dried in an oven at 80°C for 8 to 12 hours to remove residual solvent.

[0011] Furthermore, in S2, the amount of ruthenium chloride added is 4 to 10 wt% of the polyvinylpyrrolidone / betaine nanofibers.

[0012] Furthermore, in S2, the amount of iridium chloride added is 4 to 10 wt% of the polyvinylpyrrolidone / betaine nanofibers.

[0013] Furthermore, in S2, the temperature of the hydrothermal reaction is 80~100℃, for example, it can be 80℃, 90℃, 100℃, etc., and the time is 8~30h, for example, it can be 8h, 16h, 24h, 30h, etc.

[0014] Furthermore, in S3, the process conditions for heating and carbonization are: heating to 300~800℃, for example, 300℃, 500℃, 800℃, etc., and holding at that temperature for 2~6 hours. Even further, in S3, the heating rate during the heating and carbonization process is 2~8℃ / min.

[0015] Furthermore, in S3, the inert atmosphere is provided by argon or nitrogen, etc.

[0016] In a second aspect, the present invention provides a ruthenium-iridium supported porous carbon nanofiber material, which is prepared by the preparation method described in the first aspect above.

[0017] In a third aspect, this invention provides an application of ruthenium-iridium supported porous carbon nanofibers as a chlorine evolution catalyst in the chlor-alkali industry. Specifically, it is used in applications such as ion-exchange membrane chlor-alkali processes for pesticide waste salts.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) In the ruthenium-iridium supported porous carbon nanofiber material, ruthenium provides extremely high intrinsic activity, significantly reduces the overpotential of the chlorine evolution reaction, and saves electrical energy; while iridium greatly enhances the chemical stability of the catalyst in the complex and highly corrosive environment of pesticide waste salt, effectively preventing the deactivation of active components, thereby ensuring that the catalyst has both high activity and long lifespan in long-term operation.

[0019] (2) The porous carbon nanofiber carrier constructs an ideal three-dimensional reaction platform. Its high specific surface area greatly increases the number and utilization of active sites, while the continuous carbon network ensures rapid electron conduction. At the same time, the abundant porous structure not only facilitates the diffusion of reactant ions, but also promotes the rapid desorption of generated chlorine gas bubbles, avoiding the bubble shielding effect and ensuring the continuous and efficient progress of the reaction.

[0020] (3) The material directly addresses the challenge of treating pesticide waste salt. Ruthenium-iridium catalysts and porous carbon supports exhibit stronger tolerance to organic impurities and toxins in wastewater. Their high efficiency and stability make the resource utilization pathway of electrolyzing harmful waste salt into chlorine and sodium hydroxide more technically and economically feasible. At the same time, the active chlorine species that may be generated during the reaction can also synergistically degrade organic pollutants, achieving the dual environmental benefits of "treating waste with waste". Attached Figure Description

[0021] Figure 1 This is a TEM image of the ruthenium-iridium supported porous carbon nanofiber material prepared in Example 1; Figure 2 The image shows the chlorine evolution performance of the ruthenium-iridium supported porous carbon nanofiber material prepared in Example 1 in the chlor-alkali industry. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0023] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, although not explicitly stated, each point or individual value between the endpoints of a range is included within that range. Therefore, each point or individual value can be used as its own lower or upper limit and combined with any other point or individual value, or combined with other lower or upper limits, to form a range not explicitly stated. In the description of this application, it should be noted that, unless otherwise stated, "above" includes the stated number, and "multiple" in "one or more" means two or more.

[0024] The foregoing description of this application is not intended to describe every disclosed implementation or method. Instead, the following description provides more specific examples of exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments that can be used in various combinations. The examples listed are representative only and should not be construed as exhaustive.

[0025] Numerous details are explored in the following description to provide a more thorough explanation of embodiments of this application; however, it will be apparent to those skilled in the art that embodiments of this application may be practiced without these specific details.

[0026] To further understand the present invention, the following embodiments are provided for illustration.

[0027] In the following embodiments, the polyvinylpyrrolidone used is polyvinylpyrrolidone K30. It is worth noting that, unless otherwise specified, all raw materials used in this invention are commercially available; and all methods and equipment employed are common in the art.

[0028] Example 1 A ruthenium-iridium supported porous carbon nanofiber material is prepared according to the following steps: (1) Prepare the spinning solution by mixing and dissolving 1 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 2:1) powder in 8.5 g of deionized water. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 15 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0029] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 16 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0030] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of ruthenium chloride / iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers, and the mass ratio of ruthenium chloride to iridium chloride was 4:1), and placed in an autoclave. Then, the autoclave was placed in a muffle furnace and dried at 100°C for 20 h to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers. Figure 1 The TEM image shows that ruthenium and iridium are uniformly loaded onto nanofibers in the form of nanoparticles.

[0031] (4) Calcination: The above ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500 °C at a heating rate of 3 °C / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0032] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The performance of a catalyst is judged based on the current density at a given point and the corresponding conditions. For example... Figure 2 As shown, the electrode sheet in this embodiment reaches 10 mA cm⁻¹. -2The overpotential at the current density was 93 mV, significantly better than that of commercial DSA (130 mV), demonstrating superior catalytic performance for the chlorine evolution reaction. This is likely because the rod-like porous structure of carbon nanofibers greatly increases the specific surface area of ​​the material, exposing more catalytic active sites, allowing for better adsorption and reaction of Cl- ions. Simultaneously, the electronic interactions between the carbon fibers and the supported ruthenium-iridium nanoparticles optimize the electronic structure of the active sites, further enhancing catalytic performance.

[0033] Example 2: A ruthenium-iridium supported porous carbon nanofiber material is prepared according to the following steps: (1) Prepare the spinning solution by mixing and dissolving 1.5 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 3:1) powder in 8.0 g of deionized water. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 20 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0034] (2) Electrospinning to prepare composite fibers: Polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning under the conditions of spinning voltage of 16 kV, receiving distance of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25 ℃. The nanofibers were placed in a vacuum drying oven at 80 ℃ and dried for 10 h.

[0035] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of ruthenium chloride / iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers, and the mass ratio of ruthenium chloride / iridium chloride was 4:1), and placed in an autoclave. Then, the autoclave was placed in a muffle furnace and heated at 100 °C for 20 h. After 20 h, the mixture was filtered and dried to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers.

[0036] (4) Calcination: The above ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500℃ at a heating rate of 3℃ / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0037] (5) Chlorine evolution performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance is judged under the corresponding current density at a given location. In this embodiment, the electrode plate reaches 10 mA cm⁻¹. -2 The overpotential of the current density is 95 mV, which is significantly better than that of commercial DSA (130 mV), demonstrating better catalytic performance for chlorine evolution reaction.

[0038] Example 3: A ruthenium-iridium supported porous carbon nanofiber material is prepared according to the following steps: (1) Prepare the spinning solution by adding 2.0 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 4:1) powder to 10 g of deionized water and mixing and dissolving them. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 20 wt%. Stir at 25 ℃ for more than 24 h to completely dissolve and form a uniform spinning solution.

[0039] (2) Electrospinning to prepare composite fibers: Polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning under the conditions of voltage of 16 kV, receiving distance of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25 ℃. The nanofibers were placed in a vacuum drying oven at 80 ℃ and dried for 10 h.

[0040] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in water, and 10 mL of ruthenium chloride / iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers, and the mass ratio of ruthenium chloride / iridium chloride was 4:1) was added. The mixture was then placed in an autoclave and then placed in a muffle furnace. After 20 h at 100 °C, the mixture was filtered and dried to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers.

[0041] (4) Calcination: The pre-oxidized ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500 ℃ at a heating rate of 3 ℃ / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0042] (5) Chlorine evolution performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance is judged under the corresponding current density at a given location. In this embodiment, the electrode plate reaches 10 mA cm⁻¹. -2 The overpotential of the current density is 100 mV, which is significantly better than that of commercial DSA (130 mV), demonstrating better catalytic performance for chlorine evolution reaction.

[0043] Example 4: A ruthenium-iridium supported porous carbon nanofiber material is prepared according to the following steps: (1) Prepare the spinning solution by mixing and dissolving 1 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 2:1) powder in 8.5 g of deionized water. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 15 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0044] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 14 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0045] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of ruthenium chloride / iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers, and the mass ratio of ruthenium chloride / iridium chloride was 2:1), and placed in an autoclave. Then, they were placed in a muffle furnace and dried at 100°C for 20 h to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers.

[0046] (4) Calcination: The above ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500 ℃ at a heating rate of 3 ℃ / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0047] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance is judged under the corresponding current density at a given location. In this embodiment, the electrode plate reaches 10 mA cm⁻¹. -2 The overpotential of the current density is 102 mV, which is significantly better than that of commercial DSA (130 mV), demonstrating better catalytic performance for chlorine evolution reaction.

[0048] Example 5: A ruthenium-iridium supported porous carbon nanofiber material is prepared according to the following steps: (1) Prepare the spinning solution by adding 2 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 4:1) powder to 8 g of deionized water and mixing and dissolving them. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 10 wt%. Stir at 25 ℃ for more than 24 h to completely dissolve and form a uniform spinning solution.

[0049] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 15 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0050] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of ruthenium chloride / iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers, and the mass ratio of ruthenium chloride / iridium chloride was 4:1), and placed in an autoclave. Then, they were placed in a muffle furnace and dried at 100°C for 20 h to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers.

[0051] (4) Calcination: The above ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500℃ at a heating rate of 3℃ / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0052] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance is judged under the corresponding current density at a given location. In this embodiment, the electrode plate reaches 10 mA cm⁻¹. -2 The overpotential of the current density is 95 mV, which is significantly better than that of commercial DSA (130 mV), demonstrating better catalytic performance for chlorine evolution reaction.

[0053] Comparative Example 1: This comparative example is almost identical to Example 1, except that the addition of betaine is omitted.

[0054] (1) Prepare the spinning solution by taking 1 g of polyvinylpyrrolidone powder and mixing it with 9 g of deionized water. The mass fraction of polyvinylpyrrolidone powder in the mixed solution is 10 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0055] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 16 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25 ℃, polyvinylpyrrolidone composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0056] (3) Porous composite fiber: The polyvinylpyrrolidone composite nanofiber is immersed in 10 mL of ruthenium chloride / iridium chloride (mass ratio of 4:1, the total amount added is 10 wt% of the mass of polyvinylpyrrolidone composite nanofiber), and placed in an autoclave, then placed in a muffle furnace, and dried at 100℃ for 20 h to obtain ruthenium chloride / iridium chloride-polyvinylpyrrolidone nanofiber.

[0057] (4) Calcination: The above ruthenium chloride / iridium chloride-polyvinylpyrrolidone nanofibers were heated to 500°C at a heating rate of 3°C / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported carbon nanofiber material.

[0058] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance was evaluated under the corresponding current density at a given location. The comparative electrode achieved a current density of 10 mA cm⁻¹. -2 The overpotential of the current density is 180 mV, which is significantly worse than that of commercial DSA (130 mV), and it exhibits general catalytic performance for chlorine evolution reaction.

[0059] Comparative Example 2: This comparative example is almost identical to Example 1, except that the addition of ruthenium chloride is omitted.

[0060] (1) Prepare the spinning solution by mixing and dissolving 1 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 2:1) powder in 8.5 g of deionized water. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 15 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0061] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 16 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0062] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers), and placed in an autoclave. Then, they were placed in a muffle furnace and dried at 100 °C for 20 h to obtain iridium chloride-porous polyvinylpyrrolidone nanofibers.

[0063] (4) Calcination: The above iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500℃ at a heating rate of 3℃ / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain iridium-loaded porous carbon nanofiber material.

[0064] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Iridium-loaded porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell, the reference electrode was a calomel electrode with saturated potassium chloride solution, a polytetrafluoroethylene tube salt bridge was used, the experimental electrolyte was 5 M KOH solution, and the experimental current density was 2 kA / m under constant DC input. 2 The experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds; this was taken as the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential exceeding the theoretical voltage value of the chlorine evolution reaction was considered the overpotential. The closer the overpotential was to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the lower the energy consumption, and the higher the catalytic activity. A value of 10 mA cm⁻¹ was typically chosen. -2 The catalyst performance was evaluated under the corresponding current density at a given location. The comparative electrode achieved a current density of 10 mA cm⁻¹. -2 The overpotential of the current density is 210 mV, which is significantly worse than that of commercial DSA (130 mV), and it exhibits general catalytic performance for chlorine evolution reaction.

[0065] Comparative Example 3: This comparative example is almost identical to Example 1, except that the addition of iridium chloride is omitted.

[0066] (1) Prepare the spinning solution by mixing and dissolving 1 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 2:1) powder in 8.5 g of deionized water. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 15 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0067] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 16 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25 ℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0068] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of ruthenium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers), and placed in an autoclave. Then, they were placed in a muffle furnace and dried at 100 °C for 20 h to obtain ruthenium chloride-porous polyvinylpyrrolidone nanofibers.

[0069] (4) Calcination: The above ruthenium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500 °C at a heating rate of 3 °C / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-supported porous carbon nanofiber material.

[0070] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Ruthenium-supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell, the reference electrode was a calomel electrode with saturated potassium chloride solution, a polytetrafluoroethylene tube salt bridge, and the experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance was evaluated under the corresponding current density at a given location. The comparative electrode achieved a current density of 10 mA cm⁻¹. -2The overpotential of the current density is 230 mV, which is significantly worse than that of commercial DSA (130 mV), and it exhibits general catalytic performance for chlorine evolution reaction.

[0071] Comparative Example 4 It is largely the same as Example 1, except that polyvinylpyrrolidone is replaced with an equal mass of hexadecyltrimethylammonium bromide.

[0072] (1) Prepare the spinning solution by mixing and dissolving 1 g of cetyltrimethylammonium bromide and 0.5 g of betaine (mass ratio 2:1) powder in 8.5 g of deionized water. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 15 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0073] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 16 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0074] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of a solution of ruthenium chloride / iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers, and the mass ratio of ruthenium chloride / iridium chloride was 4:1), and placed in an autoclave. Then, the autoclave was placed in a muffle furnace and dried at 100°C for 20 h to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers.

[0075] (4) Calcination: The above ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500 °C at a heating rate of 3 °C / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0076] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance is judged under the corresponding current density at a given location. In this embodiment, the electrode plate reaches 10 mA cm⁻¹. -2 The overpotential of the current density is 190 mV, which is significantly worse than that of commercial DSA (130 mV), and it exhibits general catalytic performance for chlorine evolution reaction.

[0077] Comparative Example 5 The majority of the components are the same as in Example 1, except that the ruthenium chloride / iridium chloride composition is replaced with an equal mass of a platinum salt (i.e., platinum chloride).

[0078] (1) Prepare the spinning solution by mixing and dissolving 1 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 2:1) powder in 8.5 g of deionized water. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 15 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0079] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 16 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.6 mL / h, and electrospinning temperature of 25℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0080] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of a solution of platinum chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers), and placed in an autoclave. Then, they were placed in a muffle furnace and dried at 100°C for 20 h to obtain platinum chloride-porous polyvinylpyrrolidone nanofibers.

[0081] (4) Calcination: The above ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500 °C at a heating rate of 3 °C / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain platinum-supported porous carbon nanofiber material.

[0082] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Platinum-supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell, the reference electrode was a calomel electrode with saturated potassium chloride solution, a polytetrafluoroethylene tube salt bridge was used, the experimental electrolyte was 5 M NaCl solution, and the experimental current density was 2 kA / m under constant DC input. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance is judged under the corresponding current density at a given location. In this embodiment, the electrode plate reaches 10 mA cm⁻¹. -2 The overpotential of the current density is 160 mV, which is significantly worse than that of commercial DSA (130 mV), and it exhibits relatively general catalytic performance for chlorine evolution reaction.

[0083] Comparative Example 6 This comparative example is almost identical to Example 1, except that the spinning solution delivery rate was replaced with 0.1 mL / h.

[0084] A ruthenium-iridium supported porous carbon nanofiber material is prepared according to the following steps: (1) Prepare the spinning solution by mixing and dissolving 1 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 2:1) powder in 8.5 g of DMF. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 15 wt%. Stir at 25 °C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0085] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 16 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 0.1 mL / h, and electrospinning temperature of 25℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0086] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of ruthenium chloride / iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers, and the mass ratio of ruthenium chloride / iridium chloride was 4:1), and placed in an autoclave. Then, they were placed in a muffle furnace and dried at 100 °C for 20 h to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers.

[0087] (4) Calcination: The above ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500℃ at a heating rate of 3℃ / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0088] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance is judged under the corresponding current density at a given location. In this embodiment, the electrode plate reaches 10 mA cm⁻¹. -2 The overpotential of the current density is 240 mV, which is significantly worse than that of commercial DSA (130 mV), and it exhibits general catalytic performance for chlorine evolution reaction.

[0089] Comparative Example 7 This comparative example is almost identical to Example 1, except that the spinning solution delivery rate was replaced with 1.0 mL / h.

[0090] A ruthenium-iridium supported porous carbon nanofiber material is prepared according to the following steps: (1) Prepare the spinning solution by mixing and dissolving 1 g of polyvinylpyrrolidone and 0.5 g of betaine (mass ratio 2:1) powder in 8.5 g of DMF. The mass fraction of polyvinylpyrrolidone and betaine powder in the mixed solution is 15 wt%. Stir at 25°C for more than 24 h to completely dissolve and form a uniform spinning solution.

[0091] (2) Electrospinning to prepare composite fibers: Under the conditions of spinning voltage of 16 kV, receiving distance (i.e., the distance from the spinning nozzle to the receiver) of 16 cm, spinning solution push rate of 1.0 mL / h, and electrospinning temperature of 25 ℃, polyvinylpyrrolidone / betaine composite nanofibers were obtained by electrospinning and placed in a vacuum drying oven at 80℃ for 10 h.

[0092] (3) Porous composite fiber: The polyvinylpyrrolidone / betaine composite nanofibers were soaked in 10 mL of ruthenium chloride / iridium chloride (the amount added was 10 wt% of the mass of the polyvinylpyrrolidone / betaine composite nanofibers, and the mass ratio of ruthenium chloride / iridium chloride was 4:1), and placed in an autoclave. Then, they were placed in a muffle furnace and dried at 100°C for 20 h to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers.

[0093] (4) Calcination: The above ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers were heated to 500 ℃ at a heating rate of 3 ℃ / min under an argon atmosphere of 50 mL / min, held for 3 h, and then allowed to cool naturally to room temperature to obtain ruthenium-iridium supported porous carbon nanofiber material.

[0094] (5) Chlorine evolution reaction performance test in chlor-alkali industry: Ruthenium-iridium supported porous carbon nanofibers were used as the anode material of the chlor-alkali electrolytic cell. The reference electrode was a calomel electrode with saturated potassium chloride solution. A polytetrafluoroethylene tube salt bridge was used. The experimental electrolyte was a 5 M NaCl solution. Under constant DC input, the experimental current density was 2 kA / m. 2 The scan rate was 5 mV / s, and the experimental temperature was 25±2 ℃. After 10 minutes of electrolysis, the instantaneous lowest potential value was recorded within 20 seconds, which is the chlorine evolution potential of the electrode. The portion of the chlorine evolution potential that exceeds the theoretical voltage value of the chlorine evolution reaction is the overpotential. The closer the overpotential is to 0 V, the better the catalyst performance, the lower the actual voltage required to reach the relative current density, the less energy consumed, and the higher the catalytic activity. A value of 10 mA cm⁻¹ is typically chosen. -2 The catalyst performance is judged under the corresponding current density at a given location. In this embodiment, the electrode plate reaches 10 mA cm⁻¹. -2 The overpotential of the current density is 235 mV, which is significantly worse than that of commercial DSA (130 mV), and it exhibits general catalytic performance for chlorine evolution reaction.

[0095] Compared to Example 1, Comparative Examples 6 and 7 show that the spinning solution push speed in Comparative Example 6 is too slow, which leads to excessively fine fibers and low yield, thus significantly reducing mass transfer efficiency. In contrast, the spinning solution push speed in Comparative Example 7 is too fast, which causes the spinning solution to evaporate too quickly, and instead of being stretched to form fine fibers, it clumps together, causing pore blockage and a decrease in the number of exposed active sites, thereby affecting the catalytic effect.

[0096] The performance test results of the chlorine evolution reaction in the chlor-alkali industry of the examples and comparative examples are shown in Table 1 below: Table 1 As shown in the table above, a carbon nanofiber structure uniformly loaded with ruthenium and iridium was formed by adjusting the amounts of polyvinylpyrrolidone, betaine, ruthenium chloride, and iridium chloride. Examples 1-5 exhibited better catalytic performance for the chloride evolution reaction compared to Comparative Examples 1-7. Comparative Example 1, compared to Examples 1-5, omitted the addition of betaine, thus affecting its catalytic performance. Betaine, as an amphoteric ion, can form a hydrogen bond network with water molecules through its strongly hydrophilic carboxylate groups, disrupting the original hydrogen bond structure of water and significantly reducing the water activity at the interface. This inhibits the competitive oxygen evolution reaction (OER), thereby improving the selectivity of the chloride evolution reaction (CER). Simultaneously, in an acidic medium (pH=2), the cationic groups of betaine react with Cl... - The interaction weakened Cl - The hydrated shell makes it easier for the Cl to be adsorbed and activated on the electrode surface, reducing Cl... - Adsorption energy barrier. Compared to Examples 1-5, Comparative Examples 2-3 omitted the addition of ruthenium chloride or iridium chloride, resulting in reduced catalytic performance. This is because both ruthenium and iridium exhibit high selectivity for CER. Ruthenium provides high intrinsic catalytic activity, significantly reducing the reaction energy barrier, while iridium enhances the corrosion resistance and structural stability of the material under acidic conditions, inhibiting the dissolution and loss of active components. Through electronic coupling and structural synergy, both optimize the intermediate adsorption energy and provide highly efficient active sites. The absence of either one disrupts the activity-stability balance, leading to a significant decrease in catalytic performance. Compared to Examples 1-5, Comparative Example 4 used hexadecyltrimethylammonium bromide as the surfactant instead of polyvinylpyrrolidone (PVP). PVP, as a polymeric dispersant and spinning carrier, has significant advantages over other surfactants. The amide carbonyl group in its molecular structure can react with Ru... 3+ Ir 3+ Noble metal ions form strong coordination interactions, effectively inhibiting the aggregation of metal components and achieving highly uniform dispersion of the precursor. Simultaneously, PVP possesses excellent fiber-forming properties and adjustable viscosity, ensuring stability during electrospinning and yielding a continuous and uniform nanofiber structure. During high-temperature calcination, PVP can completely decompose into small gaseous molecules, leaving no residual carbon or inorganic impurities, thus avoiding poisoning or covering of catalytic active sites. Compared to Examples 1-5, Comparative Example 5 showed a significant decrease in catalytic performance after replacing the ruthenium chloride / iridium chloride dual-noble metal precursor with other conventional noble metals, mainly due to the disappearance of the bimetallic synergistic effect. Ru and Ir can optimize the electronic structure of active sites and intermediate adsorption energy through strong electronic coupling, achieving a balance between high intrinsic activity and high stability. Ru provides excellent catalytic activity, while Ir enhances the system's corrosion resistance and structural stability under acidic conditions. Replacing with a single conventional noble metal (such as Pt, Pd, Au, Rh, etc.) fails to form this type of electronic synergy and structural complementarity, easily leading to dissolution and deactivation.

[0097] In this invention, the range of process conditions involved can be arbitrarily adjusted within the following limits according to actual needs (i.e., arbitrarily adjusted to its extreme values ​​or any intermediate value): the mass ratio of polyvinylpyrrolidone to betaine is 2-4:1, and polyvinylpyrrolidone and betaine account for 10-20 wt% of the total weight of the mixed solution; The specific process conditions for electrospinning are as follows: the mixed solution is placed in a syringe and extruded by pushing a pump at a speed of 0.4 mL / h to 0.7 mL / h, the spinning voltage is controlled at 8 to 18 kV, and the distance from the spinning nozzle to the receiver is 14 to 18 cm; the resulting fiber product is dried in an oven at 80°C for 8 to 12 h to remove residual water. The amount of ruthenium chloride / iridium chloride added is 4~10 wt% of polyvinylpyrrolidone / betaine nanofibers. The specific process of heating and carbonization is as follows: control the heating rate to 2~8℃ / min, heat to 300~800℃, hold for 2~6 hours to complete the carbonization process.

[0098] The foregoing has shown and described the basic process, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing ruthenium-iridium supported porous carbon nanofiber material, characterized in that, Includes the following steps: S1. Add polyvinylpyrrolidone and betaine to a solvent, stir to obtain a uniformly dispersed spinning precursor solution, and then obtain polyvinylpyrrolidone / betaine nanofibers by electrospinning. S2. The polyvinylpyrrolidone / betaine nanofibers obtained in S1 are immersed in a mixed solution of ruthenium chloride and iridium chloride and subjected to hydrothermal reaction to obtain ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers. S3. The ruthenium chloride / iridium chloride-porous polyvinylpyrrolidone nanofibers obtained in S2 are placed under inert gas protection, heated and carbonized, and then cooled to obtain ruthenium-iridium supported porous carbon nanofiber material.

2. The method for preparing a ruthenium-iridium supported porous carbon nanofiber material according to claim 1, characterized in that, In S1, the mass ratio of polyvinylpyrrolidone to betaine is 2-4:1, and polyvinylpyrrolidone and betaine account for 8-16 wt% of the total weight of the spinning precursor solution.

3. The method for preparing a ruthenium-iridium supported porous carbon nanofiber material according to claim 1, characterized in that, In S1, the specific process conditions for electrospinning are as follows: the ejection speed is 0.4 mL / h to 0.7 mL / h, the spinning voltage is 8 to 18 kV, and the distance from the spinning nozzle to the receiver is 14 to 18 cm.

4. The method for preparing a ruthenium-iridium supported porous carbon nanofiber material according to claim 1, characterized in that, In S2, the amount of ruthenium chloride added is 4~10 wt% of polyvinylpyrrolidone / betaine nanofibers.

5. The method for preparing a ruthenium-iridium supported porous carbon nanofiber material according to claim 1, characterized in that, In S2, the amount of iridium chloride added is 4~10 wt% of the polyvinylpyrrolidone / betaine nanofibers.

6. The method for preparing a ruthenium-iridium supported porous carbon nanofiber material according to claim 1, characterized in that, In S2, the hydrothermal reaction temperature is 80~100 ℃ and the time is 8~30 h.

7. The method for preparing a ruthenium-iridium supported porous carbon nanofiber material according to claim 1, characterized in that, In S3, the process conditions for heating and carbonization are: heating to 300~800 ℃ and holding for 2~6 hours.

8. The method for preparing a ruthenium-iridium supported porous carbon nanofiber material according to claim 7, characterized in that, In S3, the heating rate during the carbonization process is 2~8 ℃ / min.

9. A ruthenium-iridium supported porous carbon nanofiber material, characterized in that, It is prepared by the preparation method described in any one of claims 1-8.

10. The application of the ruthenium-iridium supported porous carbon nanofiber material as described in claim 9 as a chlorine evolution catalyst in the chlor-alkali industry.

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