A self-supporting multi-component composite nano-catalyst for decomposing and vaporizing hydrogen peroxide and a preparation method thereof

Abstract

The application belongs to the technical field of space environment disinfection, and provides a self-supporting multi-component composite nano catalyst for decomposing and vaporizing hydrogen peroxide and a preparation method thereof. The composite nano catalyst is an AlCrFePt / NF quaternary composite nano catalyst, which comprises a catalyst active component and a catalyst active component carrier. The catalyst active component is composed of Al, Fe, Cr and Pt, the catalyst active component carrier is foam nickel, and the catalyst active component is uniformly loaded on the surface of the catalyst active component carrier base. The composite nano catalyst can efficiently decompose hydrogen peroxide into water and oxygen, and has good stability. The preparation method is a one-pot hydrothermal method, which does not require special instruments and equipment, is simple in process, cost-saving, easy to operate, and suitable for large-scale production. The problems of high cost and low catalytic efficiency of the catalyst for decomposing and vaporizing hydrogen peroxide are solved.

Description

Technical Field

[0001] This invention relates to the field of space environment disinfection technology, and in particular to a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide and its preparation method. Background Technology

[0002] Currently, traditional disinfection methods used in high-level biosafety laboratories, enclosed spaces at the site of outbreaks of infectious diseases, and biocontaminated areas such as hospital isolation wards, ambulances, and operating rooms mainly include ultraviolet disinfection, formaldehyde fumigation, and ozone disinfection. However, these methods have many drawbacks in use, such as insufficient coverage, low sterilization efficiency, strong corrosiveness, high toxicity, and long residual time. Vaporized hydrogen peroxide (VHP) disinfection, due to its advantages such as broad-spectrum bactericidal efficiency, strong penetration ability, good distribution uniformity, and material compatibility, and its ability to effectively control microbial contamination and greatly reduce the risk of hydrogen peroxide corrosion to sterile environments and equipment, has become one of the most promising space disinfection technologies.

[0003] However, after disinfection, the high concentration of vaporized hydrogen peroxide remaining in the environment is not only prone to explosion under external conditions such as light and heat, but also causes irreversible harm to human skin, eyes, and respiratory tract. Therefore, after disinfection, the concentration of hydrogen peroxide in the disinfected space must be rapidly reduced to the harmless level (<1 ppm) specified by relevant standards. This process, relying solely on natural decomposition, takes more than 8 hours, greatly prolonging the disinfection cycle and becoming one of the bottlenecks restricting the rapid disinfection of vaporized hydrogen peroxide. Catalytically decomposing vaporized hydrogen peroxide into water and oxygen through the action of an active catalyst is an efficient, simple, and safe method, and the development of high-performance catalysts is key to promoting the application of this technology.

[0004] Currently, most catalysts used for the vaporization and decomposition of hydrogen peroxide exist in powder form, which not only hinders gas flow but also causes metal dust pollution. Furthermore, bonding powdered catalysts to the filter surface can lead to problems such as weak adhesion, affecting catalytic efficiency. The precious metal Pt is considered an effective active component for the catalytic decomposition of hydrogen peroxide; however, Pt resources are scarce and its high cost limits its widespread industrial application.

[0005] Therefore, there is an urgent need for a low-cost, high-efficiency composite nanocatalyst for the decomposition of vaporized hydrogen peroxide, which would enable the widespread industrial application of this catalyst and the rapid decomposition of residual vaporized hydrogen peroxide in the environment. Summary of the Invention

[0006] This invention provides a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide and its preparation method, which solves the problems of high cost and low catalytic efficiency of current catalysts used for the decomposition of vaporized hydrogen peroxide.

[0007] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] Firstly, this invention provides a method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide, comprising: S1, pretreating nickel foam to obtain pretreated nickel foam, and transferring it to a reaction vessel; S2, adding Al salt, Cr salt, Fe salt, Pt salt and urea to ultrapure water respectively, and performing magnetic stirring to obtain a precursor solution; S3, transferring the precursor solution to the reaction vessel, and performing hydrothermal reaction treatment on the pretreated nickel foam and the precursor solution, cooling to room temperature to obtain a hydrothermal reaction product; S4, washing the hydrothermal reaction product with ethanol and ultrapure water, and drying it to obtain the self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide.

[0009] Further, the pretreatment of the nickel foam to obtain pretreated nickel foam, and its transfer to a reaction vessel, includes: S11, adding the nickel foam to a propanol solution and performing a degreasing treatment to obtain degreased nickel foam; S12, adding the degreased nickel foam to an anhydrous ethanol solution and performing an immersion treatment; S13, adding the degreased nickel foam soaked in anhydrous ethanol solution to a hydrochloric acid solution and performing an immersion treatment to obtain the pretreated nickel foam; S14, transferring the pretreated nickel foam to a reaction vessel.

[0010] Furthermore, the degreasing temperature is 20-25°C and the time is 10-20 minutes; the soaking temperature is 20-25°C and the time is 10-20 minutes.

[0011] Furthermore, the Al salt, the Fe salt, and the Cr salt are all one of chloride salts and nitrate salts; the Pt salt is one of chloroplatinic acid, sodium chloroplatinate, and potassium chloroplatinate.

[0012] Furthermore, the molar ratios of the Al salt, the Fe salt, the Cr salt, the Pt salt, and the urea are 1:8-10, 1:8-20, 1:5-8, and 1:100-400, respectively.

[0013] Furthermore, the hydrothermal reaction is carried out at a temperature of 100–200°C for a duration of 6–12 hours.

[0014] Furthermore, the drying temperature is 60–80°C, and the drying time is 4–6 hours.

[0015] Furthermore, the preparation method is a one-pot method.

[0016] Secondly, this invention provides a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide. The composite nanocatalyst is an AlCrFePt / NF quaternary composite nanocatalyst. The AlCrFePt / NF quaternary composite nanocatalyst includes a catalyst active component and a catalyst active component support. The catalyst active component is composed of Al, Fe, Cr, and Pt. The catalyst active component support is nickel foam. The catalyst active component is uniformly loaded on the surface of the catalyst active component support substrate.

[0017] Furthermore, the active component of the catalyst is nanoparticles; the average particle size of the nanoparticles is 470 nm.

[0018] The beneficial effects of this invention are that, compared with existing technologies, it provides a self-supporting multi-component composite nanocatalyst for the decomposition and vaporization of hydrogen peroxide and its preparation method. The prepared noble metal Pt-transition metal composite catalyst not only facilitates gas flow but also efficiently and stably decomposes and vaporizes hydrogen peroxide. Transition metals possess low cost, rich and tunable elemental composition, and multidimensional morphological structures, which can significantly improve the dispersion of noble metals and also exhibit synergistic effects with noble metal Pt, enhancing the catalytic activity and stability of the composite catalyst. The noble metal Pt-transition metal composite catalyst is prepared using a simple one-pot method. This preparation process is simple, cost-effective, easy to operate, and can be mass-produced. The equipment requirements are low; only an oven and a reaction vessel are needed to complete the entire synthesis process. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0020] Figure 1 The image shown is a scanning electron microscope (SEM) image of a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to an embodiment of the present invention.

[0021] Figure 2 The following are transmission electron microscope (TEM) images of a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to an embodiment of the present invention at different magnifications: a) TEM image at 5 nm; b) TEM image at 1 nm.

[0022] Figure 3 The X-ray diffraction (XRD) pattern of a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to an embodiment of the present invention is shown.

[0023] Figure 4The X-ray photoelectron spectroscopy (XPS) spectrum of a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to an embodiment of the present invention is shown.

[0024] Figure 5 An experimental platform for evaluating the catalytic decomposition performance of hydrogen peroxide according to an embodiment of the present invention is shown.

[0025] Figure 6 The diagram shows the cyclic stability of a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to an embodiment of the present invention. Detailed Implementation

[0026] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0028] Unless otherwise stated, all materials and reagents used in the following examples are commercially available.

[0029] This invention designs and develops a self-supporting multi-component nanocatalyst based on nickel foam as a substrate, which is a transition metal-noble metal Pt composite. The catalyst's in-situ growth of active components on the surface of a three-dimensional network metal substrate not only improves the low gas processing rate but also significantly enhances the composite material's performance by strengthening the bond between the active components and the substrate. The transition metal in this catalyst is inexpensive, has a rich and tunable elemental composition, and a multi-dimensional morphology, which not only significantly improves the dispersion of the noble metal but also produces a synergistic effect with it, enhancing the catalytic activity and stability of the composite material. This catalyst not only possesses high catalytic activity and stability but also exhibits self-supporting capabilities, allowing for direct use as a monolithic catalyst. Furthermore, it meets the requirements for recycling, enabling efficient catalytic decomposition of residual vaporized hydrogen peroxide in the environment, thereby facilitating rapid disinfection and reuse of the work environment.

[0030] Pretreatment of nickel foam:

[0031] At room temperature, the nickel foam was first degreased by immersing it in propanol solution for 15 minutes. Then, it was immersed in anhydrous ethanol solution for 15 minutes to remove any possible organic impurities. Finally, it was immersed in 3M hydrochloric acid for 15 minutes to remove insoluble impurities and surface metal oxides, resulting in pretreated nickel foam.

[0032] Example 1:

[0033] Weigh 4.918g AlCl3, 9.608g CrCl3, 2.225g FeCl3, 0.36g Na2PtCl6, and 9g urea, mix them, and dissolve them in 150ml of ultrapure water. Stir magnetically for 20min to obtain a homogeneous precursor solution. Transfer the precursor solution to a 250mL hydrothermal reactor containing pretreated nickel foam (50*50*10mm), and place the reactor in an oven. React at 140℃ for 10h. After cooling to room temperature, remove the hydrothermal reaction product, wash it three times with ethanol and ultrapure water, and then dry it in a vacuum oven at 60℃ for 4h to obtain the AlCrFePt / NF quaternary composite catalyst.

[0034] The morphology and structure of the AlCrFePt / NF quaternary composite catalysts prepared in Example 1 were characterized. The morphology of the AlCrFePt / NF quaternary composite catalysts prepared in Example 1 was analyzed using scanning electron microscopy (SEM), and the results are as follows: Figure 1 As shown, the catalyst active component is loaded on the surface of the nickel foam substrate in the form of nanoparticles and is distributed relatively uniformly with an average particle size of 470 nm.

[0035] The composition and structure of the AlCrFePt / NF quaternary composite catalyst prepared in Example 1 were analyzed using transmission electron microscopy (TEM), and the results are as follows: Figure 2 As shown in Figure a, obvious lattice fringes appear, indicating that the AlCrFePt / NF quaternary composite catalyst prepared in Example 1 has good crystallinity. Figure 2 As shown in b, the lattice fringes with d = 0.208 nm and 0.228 nm correspond to the Ni(111) and Pt(111) crystal planes, respectively.

[0036] The crystal structure of the AlCrFePt / NF quaternary composite catalyst prepared in Example 1 was analyzed using X-ray diffraction, and the results are as follows: Figure 3 As shown, sharp diffraction peaks appeared at 2θ = 44.83°, 52.228°, and 76.807°, corresponding to the (110), (200), and (220) crystal planes of Ni, respectively. This is because the substrate is nickel foam. Meanwhile, a broad peak appeared near 2θ = 40°, which, after comparison with the Pt PDF standard card, was found to belong to the (111) crystal plane of Pt. Furthermore, no peaks related to Al, Cr, or Fe elements were found, indicating that they exist in an amorphous form, a phenomenon consistent with the TEM results.

[0037] The composition and chemical state of the AlCrFePt / NF quaternary composite catalyst prepared in Example 1 were analyzed using X-ray photoelectron spectroscopy, and the results are as follows: Figure 4As shown, the sample contains six elements: Al, Cr, Fe, Ni, Pt, and O, indicating that four metals, Al, Cr, Fe, and Pt, were successfully loaded onto the surface of nickel foam.

[0038] The catalyst prepared in Example 1 was subjected to 10 repeated experiments to evaluate its cycle stability. The test results are as follows: Figure 6 In 10 repeated experiments, the decomposition time fluctuated within a small range of 10 minutes, indicating that the catalyst has good stability and can be recovered and reused.

[0039] Example 2:

[0040] Weigh 4.918g AlCl3, 9.608g CrCl3, 2.225g FeCl3, 0.36g Na2PtCl6, and 9g urea, mix them, and dissolve them in 150ml of ultrapure water. Stir magnetically for 20min to obtain a homogeneous precursor solution. Transfer the precursor solution to a 250mL hydrothermal reactor containing pretreated nickel foam (50*50*10mm), and place the reactor in an oven. React at 120℃ for 10h. After cooling to room temperature, remove the hydrothermal reaction product, wash it three times with ethanol and ultrapure water, and then dry it in a vacuum oven at 60℃ for 4h to obtain the AlCrFePt / NF quaternary composite catalyst.

[0041] Example 3:

[0042] Weigh 4.918g AlCl3, 9.608g CrCl3, 2.225g FeCl3, 0.36g Na2PtCl6, and 9g urea, mix them, and dissolve them in 150ml of ultrapure water. Stir magnetically for 20min to obtain a homogeneous precursor solution. Transfer the precursor solution to a 250mL hydrothermal reactor containing pretreated nickel foam (50*50*10mm), and place the reactor in an oven. React at 160℃ for 10h. After cooling to room temperature, remove the hydrothermal reaction product, wash it three times with ethanol and ultrapure water, and then dry it in a vacuum oven at 60℃ for 4h to obtain the AlCrFePt / NF quaternary composite catalyst.

[0043] Example 4:

[0044] Weigh 4.918g AlCl3, 9.608g CrCl3, 2.225g FeCl3, 0.36g Na2PtCl6, and 9g urea, mix them, and dissolve them in 150ml of ultrapure water. Stir magnetically for 20min to obtain a homogeneous precursor solution. Transfer the precursor solution to a 250mL hydrothermal reactor containing pretreated nickel foam (50*50*10mm), and place the reactor in an oven. React at 140℃ for 6h. After cooling to room temperature, remove the hydrothermal reaction product, wash it three times with ethanol and ultrapure water, and then dry it in a vacuum oven at 60℃ for 4h to obtain the AlCrFePt / NF quaternary composite catalyst.

[0045] Example 5:

[0046] Weigh 4.918g AlCl3, 9.608g CrCl3, 2.225g FeCl3, 0.36g Na2PtCl6, and 9g urea, mix them, and dissolve them in 150ml of ultrapure water. Stir magnetically for 20min to obtain a homogeneous precursor solution. Transfer the precursor solution to a 250mL hydrothermal reactor containing pretreated nickel foam (50*50*10mm), and place the reactor in an oven. React at 140℃ for 12h. After cooling to room temperature, remove the hydrothermal reaction product, wash it three times with ethanol and ultrapure water, and then dry it in a vacuum oven at 60℃ for 4h to obtain the AlCrFePt / NF quaternary composite catalyst.

[0047] Example 6:

[0048] Weigh 4.918g AlCl3, 9.608g CrCl3, 2.225g FeCl3, 0.18g Na2PtCl6, and 9g urea, mix them, and dissolve them in 150ml of ultrapure water. Stir magnetically for 20min to obtain a homogeneous precursor solution. Transfer the precursor solution to a 250mL hydrothermal reactor containing pretreated nickel foam (50*50*10mm), and place the reactor in an oven. React at 140℃ for 10h. After cooling to room temperature, remove the hydrothermal reaction product, wash it three times with ethanol and ultrapure water, and then dry it in a vacuum oven at 60℃ for 4h to obtain the AlCrFePt / NF quaternary composite catalyst.

[0049] Example 7:

[0050] Weigh 4.918g AlCl3, 9.608g CrCl3, 2.225g FeCl3, 0.72g Na2PtCl6, and 9g urea, mix them, and dissolve them in 150ml of ultrapure water. Stir magnetically for 20 minutes to obtain a homogeneous precursor solution. Transfer the precursor solution to a 250mL hydrothermal reactor containing pretreated nickel foam (50*50*10mm), and place the reactor in an oven. React at 140℃ for 10h. After cooling to room temperature, remove the hydrothermal reaction product, wash it three times with ethanol and ultrapure water, and then dry it in a vacuum oven at 60℃ for 4h to obtain the AlCrFePt / NF quaternary composite catalyst.

[0051] The catalysts prepared in the above examples were subjected to hydrogen peroxide catalytic decomposition performance tests. For example... Figure 5 As shown, a small-scale experimental platform for the catalytic decomposition of vaporized hydrogen peroxide was constructed. Liquid hydrogen peroxide was dripped onto a flash plate under the action of a peristaltic pump. The temperature of the flash plate was 120-150℃, and the injection time was 10 minutes. When the concentration in the airtight experimental chamber dropped to 250 ppm, the fan was turned on, and the fan drove the vaporized hydrogen peroxide in the chamber through the catalyst to start the catalytic decomposition experiment. The main evaluation index of the catalytic decomposition performance of hydrogen peroxide was the catalytic decomposition time (the time required for the hydrogen peroxide concentration in the space environment to decrease from 250 ppm to 1 ppm). Hydrogen peroxide concentration data were collected using an HPP272 sensor. The catalytic performance test results of the catalysts prepared in the above embodiments are shown in Table 1. As can be seen from Table 1, the natural decomposition of vaporized hydrogen peroxide takes a long time, exceeding 8 hours. In the presence of a catalyst, the catalytic decomposition performance of the catalysts prepared in different embodiments varies to some extent. The highest decomposition rate can be increased by more than 8 times, which greatly shortens the decomposition time and improves the disinfection efficiency.

[0052] Table 1 Catalytic decomposition performance of hydrogen peroxide by transition metal-noble metal Pt composite catalysts

[0053]

[0054] As can be seen from the above embodiments, the self-supported multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide prepared by the method of the present invention is an AlCrFePt / NF quaternary composite catalyst. It can efficiently decompose hydrogen peroxide into water and oxygen, improving disinfection efficiency, shortening the disinfection cycle, and exhibiting good stability. It can be recovered and reused repeatedly. The preparation method of the present invention is a one-pot hydrothermal method, requiring no special equipment, with a simple process, cost-effectiveness, and ease of operation, making it suitable for large-scale production.

Claims

1. A method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide, characterized in that, include: S1, pretreat the nickel foam to obtain pretreated nickel foam, and transfer it to the reactor; S2, Al salt, Cr salt, Fe salt, Pt salt and urea are added to ultrapure water and magnetically stirred to obtain a precursor solution; S3, the precursor solution is transferred to the reaction vessel, and the pretreated nickel foam and the precursor solution are subjected to hydrothermal reaction treatment, and then cooled to room temperature to obtain the hydrothermal reaction product; S4. The hydrothermal reaction product is washed with ethanol and ultrapure water and then dried to obtain the self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide.

2. The method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to claim 1, characterized in that, The process of pretreating nickel foam to obtain pretreated nickel foam and transferring it to a reaction vessel includes: S11, the foamed nickel is added to a propanol solution and degreased to obtain degreased foamed nickel; S12, the degreased nickel foam is added to anhydrous ethanol solution and soaked. S13, the degreased foam nickel soaked in anhydrous ethanol solution is added to hydrochloric acid solution and soaked to obtain the pretreated foam nickel; S14, the pretreated nickel foam is transferred to the reactor.

3. The method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to claim 2, characterized in that, The degreasing temperature is 20-25℃ and the time is 10-20 minutes; the soaking temperature is 20-25℃ and the time is 10-20 minutes.

4. The method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to claim 1, characterized in that, The Al salt, the Fe salt, and the Cr salt are all one of chloride salts and nitrate salts; the Pt salt is one of chloroplatinic acid, sodium chloroplatinate, and potassium chloroplatinate.

5. The method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to claim 1, characterized in that, The molar ratios of the Al salt, Fe salt, Cr salt, Pt salt, and urea are 1:8-10, 1:8-20, 1:5-8, and 1:100-400, respectively.

6. The method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to claim 1, characterized in that, The hydrothermal reaction is carried out at a temperature of 100–200°C for 6–12 hours.

7. The method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to claim 1, characterized in that, The drying temperature is 60–80°C, and the time is 4–6 hours.

8. The method for preparing a self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to claim 1, characterized in that, The preparation method is a one-pot method.

9. A self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide, characterized in that, The composite nanocatalyst is prepared by any one of the preparation methods described in claims 1 to 8, and is an AlCrFePt / NF quaternary composite nanocatalyst. The AlCrFePt / NF quaternary composite nanocatalyst comprises an active catalyst component and a support for the active catalyst component; the active catalyst component is composed of Al, Fe, Cr and Pt; and the support for the active catalyst component is nickel foam. The catalyst active component is uniformly loaded on the surface of the catalyst active component support substrate.

10. The self-supporting multi-component composite nanocatalyst for decomposing and vaporizing hydrogen peroxide according to claim 9, characterized in that, The active component of the catalyst is nanoparticles; the average particle size of the nanoparticles is 470 nm.

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