Chlorine corrosion resistant supported catalyst, its preparation method and application

Abstract

The application discloses a chlorine corrosion resistant supported catalyst and a preparation method and application thereof, and belongs to the technical field of electrocatalytic materials, and comprises the following steps: firstly, dispersing zirconium nitrate and metal salt in a solution, controlling the pH value of the solution to be weak alkaline, then aging and centrifuging to obtain a precursor A; finally, calcining the precursor A to obtain the chlorine corrosion resistant supported catalyst. The chlorine corrosion resistant supported catalyst and the preparation method and application thereof are used, the prepared chlorine corrosion resistant supported catalyst has rich Lewis acid sites, can adsorb Lewis base OH ‑ in seawater to generate a hydroxyl layer repelling Cl ‑ in seawater, so that the activity and stability of the catalyst are enhanced, and efficient seawater electrolysis is realized.

Description

Technical Field

[0001] This invention relates to the field of electrocatalytic materials technology, and in particular to a chlorine-resistant supported catalyst, its preparation method, and its application. Background Technology

[0002] With the growing global demand for green hydrogen energy, direct seawater electrolysis for hydrogen production is considered one of the most sustainable solutions. However, the high concentration of chloride ions (Cl-) in seawater... - The presence of Cl- poses a fundamental challenge to the anode of the oxygen evolution reaction (OER). At the operating potential, Cl- - It will compete with the OER for oxidation, producing chlorine or hypochlorite. This not only significantly reduces the current efficiency and hydrogen production efficiency of the OER, but the strongly oxidizing chlorine species produced will also severely corrode the catalyst active site and support, leading to the loss of precious metals and structural collapse, causing rapid catalyst deactivation. At the same time, the by-product toxic chlorine gas also brings separation challenges and safety risks.

[0003] Existing technologies mostly employ passive strategies such as external pH adjustment, the use of diaphragms, or the development of resistant catalysts. However, these strategies suffer from drawbacks such as increased system complexity, high costs, or insufficient long-term stability. Therefore, developing an anode catalyst that can actively exclude chloride ion interference, preferentially select OER, and possess both high activity and high stability is key to overcoming the bottlenecks in seawater electrolysis technology. Summary of the Invention

[0004] The purpose of this invention is to provide a chlorine-resistant supported catalyst, its preparation method, and its application. The prepared chlorine-resistant supported catalyst has abundant Lewis acid sites and adsorbs Lewis bases (OH). - The formation of a hydroxyl layer repels Cl from seawater. - This enhances the activity and stability of the catalyst, enabling efficient seawater electrolysis.

[0005] To achieve the above objectives, the present invention provides a method for preparing a supported catalyst resistant to chlorine corrosion, comprising the following steps: S1. Disperse zirconium nitrate and metal salt in a solvent, adjust the pH of the solution to make it weakly alkaline, and then age and centrifuge to obtain precursor A; S2. Precursor A is calcined, kept warm, and cooled to obtain a supported catalyst resistant to chlorine corrosion.

[0006] Preferably, the concentration of zirconium nitrate in S1 is 1-6 mmol.

[0007] Preferably, in S1, the metal salt is one or more of iridium trichloride, iridium acetylacetonate, and yttrium chloride.

[0008] Preferably, in S1, the solution is deionized water, the solution volume is 20-100 mL, and the dispersion time is 20-40 min.

[0009] Preferably, in S1, the reagent for adjusting the pH of the solution is ammonia water, and the pH is adjusted to 9-11.

[0010] Preferably, in S1, the aging time is 1-5 hours and the aging temperature is 20-50℃.

[0011] Preferably, in S2, the calcination temperature is 500-900℃, the calcination heating rate is 2-10℃ / min, the calcination holding time is 1-5h, and then it is cooled to room temperature.

[0012] The present invention also provides a chlorine-resistant supported catalyst, which is prepared by the method described above for preparing a chlorine-resistant supported catalyst.

[0013] The present invention also provides an application of a chlorine-resistant supported catalyst, wherein the chlorine-resistant supported catalyst prepared by the above-described method is applied to the electrolysis of seawater to produce hydrogen.

[0014] Therefore, the present invention employs the above-mentioned supported catalyst resistant to chlorine corrosion, its preparation method, and its application, which has the following beneficial effects: (1) By employing electronic regulation and thermodynamic inhibition strategies, the electronic structure of the active sites of IrO2 was optimized by utilizing the strong interaction between the support ZrO2 and IrO2, significantly reducing the OER overpotential and making OER thermodynamically preferential over the chlorine evolution reaction; at the same time, the Lewis acidity of the support was used to adsorb negatively charged hydroxyl groups, forming a hydroxyl layer, which blocked Cl through electrostatic repulsion. - The IrO2 nanoparticles are firmly anchored by strong metal-support interactions, while the highly stable ZrO2 support itself can effectively resist corrosion from chloride-containing oxide species, providing both physical and chemical protection for the active center. (2) The preparation method of the chlorine corrosion resistant supported catalyst is simple, easy to operate and low in cost. The prepared chlorine corrosion resistant supported catalyst has good electrochemical activity and high stability. When applied to the OER reaction of seawater electrolysis, it can show excellent electrochemical performance, providing a new research scheme for the industrial application of seawater electrolysis.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1This is the XRD pattern of the chlorine-resistant supported catalyst of the present invention, its preparation method and application example 1. Figure 2 This is a TEM image of a chlorine-resistant supported catalyst of the present invention, its preparation method, and the chlorine-resistant supported catalyst prepared in Example 1. Figure 3 This is a graph showing the anodic oxygen evolution performance test results of Example 1 and Comparative Example 1 of the present invention, which describes a supported catalyst resistant to chlorine corrosion, its preparation method, and its application. Figure 4 This is a graph showing the anodic oxygen evolution stability test results of the supported catalyst resistant to chlorine corrosion of the present invention, its preparation method, and application example 1. Detailed Implementation

[0017] This invention provides a method for preparing a supported catalyst resistant to chlorine corrosion, comprising the following steps: S1. Disperse zirconium nitrate and metal salt in a solvent, adjust the pH of the solution to make it weakly alkaline, and then age and centrifuge to obtain precursor A.

[0018] In this invention, the concentration of zirconium nitrate in S1 is 1-6 mmol.

[0019] In this invention, in S1, the metal salt is one or more of iridium trichloride, iridium acetylacetonate, and yttrium chloride.

[0020] In this invention, in S1, the solution is deionized water, the solution volume is 20-100 mL, and the dispersion time is 20-40 min.

[0021] In this invention, in step S1, ammonia is used to adjust the pH of the solution to 9-11. Adjusting the pH to a slightly alkaline state with ammonia promotes hydrolysis or precipitation of metal ions, forming hydroxide or oxide precursors. Alkaline conditions are beneficial for generating precipitates with uniform particle size and stable structure. Simultaneously, the NH3 in the ammonia may participate in coordination, affecting the morphology of the precipitate. Maintaining the pH at 9-11 avoids excessive precipitation leading to particle agglomeration and also provides a suitable environment for subsequent aging.

[0022] In this invention, in step S1, the aging time is 1-5 hours, and the aging temperature is 20-50°C. The aging process allows the newly formed precipitate to stand in the mother liquor for a period of time, aiming to allow the precipitate particles to further grow and crystallize, eliminate internal defects, and improve the structural stability and uniformity of the precursor. The choice of aging temperature and time affects the grain size and specific surface area, thus affecting the performance of the final catalyst.

[0023] S2. Precursor A is calcined, kept warm, and cooled to obtain a supported catalyst resistant to chlorine corrosion.

[0024] Calcination involves heat-treating precursor A at high temperatures, causing the hydroxide or other precursors to decompose and transform into oxides. Zirconium nitrate decomposes to generate a ZrO2 support, while metal salts decompose to generate corresponding metal oxides (such as IrO2, Y2O3) or elemental metals (depending on the atmosphere, but usually an oxidizing atmosphere). At high temperatures, interactions may occur between the active component and the support, forming a stable supported structure, while simultaneously removing volatile components from the precursor (such as H2O, CO2, NO). x (etc.). Controlling the heating rate can prevent violent decomposition that could lead to structural collapse.

[0025] In this invention, in S2, the calcination temperature is 500-900℃, the calcination heating rate is 2-10℃ / min, the calcination holding time is 1-5h, and then it is cooled to room temperature.

[0026] Holding the catalyst at the target temperature for a sufficient time ensures complete decomposition of the precursor and allows for sufficient crystallization of the support and active components, forming the desired crystalline phase and porous structure. The holding time affects the crystallite size, specific surface area, and dispersion of the active components, thereby influencing catalytic performance and resistance to chlorine corrosion.

[0027] The present invention also provides a chlorine-resistant supported catalyst, which is prepared by the method described above for preparing a chlorine-resistant supported catalyst.

[0028] The present invention also provides an application of a chlorine-resistant supported catalyst, characterized in that: the chlorine-resistant supported catalyst prepared by the above-described method is applied to the electrolysis of seawater to produce hydrogen.

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention. Furthermore, it should be understood that after reading the contents of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims and are all within the protection scope of the present invention.

[0030] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0031] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0032] In this invention, unless otherwise specified, all other test materials and instruments are conventional test materials in the field and can be purchased through commercial channels.

[0033] Example 1 This invention provides a supported catalyst resistant to chlorine corrosion, the preparation method of which includes the following steps: S1. Disperse zirconium nitrate and iridium trichloride in 60 mL of aqueous solution, sonicate for 30 min to make it uniform, then slowly add ammonia solution, observe the pH value of the solution with a pH instrument until the pH reaches 10, then age at 30 °C for 2 h, and centrifuge to obtain precursor A. S2. Weigh 50 mg of precursor A and calcine it in a muffle furnace at a temperature of 600 °C for 3 h with a heating rate of 5 °C / min. After cooling to room temperature, a chlorine-resistant supported catalyst (IrO2 / ZrO2) is obtained.

[0034] Example 2 This invention provides a supported catalyst resistant to chlorine corrosion, the preparation method of which includes the following steps: S1. Disperse zirconium nitrate and iridium trichloride in 60 mL of aqueous solution, sonicate for 30 min to make it uniform, then slowly add ammonia solution, observe the pH value of the solution with a pH instrument until the pH reaches 10, then age at 30 °C for 1 h, and centrifuge to obtain precursor A. S2. Weigh 50 mg of precursor A and calcine it in a muffle furnace at a temperature of 900 °C for 3 h with a heating rate of 5 °C / min. After cooling to room temperature, a supported catalyst resistant to chlorine corrosion is obtained.

[0035] Example 3 This invention provides a supported catalyst resistant to chlorine corrosion, the preparation method of which includes the following steps: S1. Disperse zirconium nitrate and iridium trichloride in 50 mL of aqueous solution, sonicate for 30 min to make it uniform, then slowly add ammonia solution, observe the pH value of the solution with a pH instrument until the pH reaches 10, then age at 30 °C for 2 h, and centrifuge to obtain precursor A. S2. Weigh 50 mg of precursor A and calcine it in a muffle furnace at a temperature of 900 °C for 3 h with a heating rate of 5 °C / min. After cooling to room temperature, a supported catalyst resistant to chlorine corrosion is obtained.

[0036] Comparative Example 1 This comparative example uses a commercially available IrO2 catalyst purchased from Macklin, CAS number 12030-49-8.

[0037] Comparative Example 2 This comparative example obtained an IrO2-ZrO2 composite catalyst by grinding and mixing commercial IrO2 and then calcining it in a muffle furnace at 300°C for 2 hours.

[0038] The supported catalyst resistant to chlorine corrosion prepared in Example 1 was characterized, and the results are as follows: The composition of the chlorine-resistant supported catalyst prepared in Example 1 was analyzed using X-ray diffraction. The XRD results are as follows: Figure 1 As shown. From Figure 1 It can be seen that the characteristic peaks of the chlorine-resistant supported catalyst prepared in Example 1 correspond to those of the standard card, confirming that the present invention has successfully prepared the IrO2 / ZrO2 catalyst.

[0039] The supported catalyst resistant to chlorine corrosion prepared in Example 1 was observed using field emission transmission electron microscopy (TEM), and the results are as follows: Figure 2 As shown. From Figure 2 It can be seen that the chlorine-resistant supported catalyst prepared by this invention has been successfully prepared.

[0040] The anodic oxygen evolution performance of the chlorine-resistant supported catalyst prepared in Example 1 and the commercially available catalyst IrO2 in Comparative Example 1 was tested. The specific operation was as follows: A three-electrode system was used, with the chlorine-resistant supported catalyst prepared in Example 1, the commercially available IrO2 catalyst from Comparative Example 1, and the IrO2-ZrO2 composite catalyst as anodes. Linear scan tests were performed at a scan rate of 5 mV / s under seawater electrolyte conditions. The results are as follows: Figure 3 As shown. From Figure 3It can be seen that the oxygen evolution performance of the IrO2 / ZrO2 catalyst prepared in Example 1 is better than that of the IrO2 catalyst in Comparative Example 1 and the IrO2-ZrO2 catalyst in Comparative Example 2, which further demonstrates that the chlorine-resistant supported catalyst prepared by the method of the present invention has excellent electrochemical activity.

[0041] The reason for the above situation is that in Example 1, Zr and Ir were uniformly mixed by co-precipitation and calcined at 600°C to form a solid solution or a highly dispersed composite oxide structure. This structure allows the stability of ZrO2 and the activity of IrO2 to work synergistically, enhancing the catalyst's corrosion resistance in a chloride ion environment.

[0042] In contrast, although the pure IrO2 in Comparative Example 1 has good activity, it is prone to reaction pathways involving lattice oxygen in the presence of chloride ions, leading to structural collapse; the simple mixture in Comparative Example 2 failed to achieve atomic-level interactions, so its corrosion resistance and activity were both poor.

[0043] The anodic oxygen evolution stability test was performed on the supported catalyst resistant to chlorine corrosion prepared in Example 1. The specific operation was as follows: Using a three-electrode system with the chlorine-resistant supported catalyst prepared in Example 1 as the anode and seawater as the electrolyte, the potentiostatic method was employed at 10 mA·cm⁻¹. -2 The oxygen evolution stability of the IrO2 / ZrO2 catalyst was tested at a given current density. The results are as follows: Figure 4 As shown. From Figure 4 It can be seen that the IrO2 / ZrO2 catalyst prepared by this invention can operate stably for more than 200 hours, exhibiting excellent stability.

[0044] Therefore, this invention employs the above-mentioned chlorine-resistant supported catalyst, its preparation method, and its application. The prepared chlorine-resistant supported catalyst has abundant Lewis acid sites and adsorbs Lewis base OH. - The formation of a hydroxyl layer repels Cl from seawater. - This enhances the activity and stability of the catalyst, enabling efficient seawater electrolysis.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a supported catalyst resistant to chlorine corrosion, characterized in that: Includes the following steps: S1. Disperse zirconium nitrate and metal salt in a solution, adjust the pH of the solution to make it weakly alkaline, and then age and centrifuge to obtain precursor A; S2. Precursor A is calcined, kept warm, and cooled to obtain a supported catalyst resistant to chlorine corrosion.

2. The method for preparing a chlorine-resistant supported catalyst according to claim 1, characterized in that: In S1, the concentration of zirconium nitrate is 1-6 mmol.

3. The method for preparing a chlorine-resistant supported catalyst according to claim 1, characterized in that: In S1, the metal salt is one or more of iridium trichloride, iridium acetylacetonate, and yttrium chloride.

4. The method for preparing a chlorine-resistant supported catalyst according to claim 1, characterized in that: In S1, the solution is deionized water, the solution volume is 20-100 mL, and the dispersion time is 20-40 min.

5. The method for preparing a chlorine-resistant supported catalyst according to claim 1, characterized in that: In S1, the reagent used to adjust the pH of the solution is ammonia water, and the pH is adjusted to 9-11.

6. The method for preparing a chlorine-resistant supported catalyst according to claim 1, characterized in that: In S1, the aging time is 1-5 hours and the aging temperature is 20-50℃.

7. The method for preparing a chlorine-resistant supported catalyst according to claim 1, characterized in that: In S2, the calcination temperature is 500-900℃, the calcination heating rate is 2-10℃ / min, the calcination holding time is 1-5h, and then it is cooled to room temperature.

8. A supported catalyst resistant to chlorine corrosion, characterized in that: It was prepared using the method for preparing a chlorine-resistant supported catalyst according to any one of claims 1-7.

9. The application of a chlorine-resistant supported catalyst, characterized in that: The chlorine-resistant supported catalyst prepared by the method of any one of claims 1-7 is applied to the electrolysis of seawater to produce hydrogen.

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