Preparation method of copper oxide catalyst and its application in catalytic decomposition of ozone

Abstract

The present invention relates to a method for preparing a copper oxide catalyst and its application in catalytic decomposition of ozone, belonging to the technical field of catalytic decomposition of gaseous pollutants and environmental protection. The preparation method comprises dissolving copper acetate monohydrate in deionized water to obtain a first solution; dissolving a pH regulator in deionized water to obtain a second solution; adding the second solution dropwise to the first solution, controlling the pH value of the reaction solution, and stirring at room temperature to obtain a suspension; centrifuging the suspension, washing the resulting precipitate with deionized water until the filtrate is neutral, collecting the solid phase by suction filtration, and finally drying to obtain a copper oxide precursor; calcining the copper oxide precursor in an air atmosphere, collecting the solid phase and sieving it to obtain mesoporous nanosheet copper oxide. The copper oxide of the present invention, as an ozone decomposition catalyst, can efficiently catalytically decompose ozone under high ozone concentrations, high mass space velocities, and a wide humidity range, achieving high activity and stability in removing ozone under high humidity conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalytic decomposition of gaseous pollutants and environmental protection, and particularly relates to a preparation method of a copper oxide catalyst and application of the same in catalytic decomposition of ozone. Background Art

[0002] Ozone decomposition refers to the process of decomposing ozone molecules into oxygen molecules under suitable conditions. It can be achieved through photolysis, thermal decomposition or catalytic decomposition. Catalytic decomposition technology has attracted widespread attention due to its high efficiency, mild reaction conditions, no additional energy consumption and no secondary pollutants. Traditional ozone decomposition catalysts, such as manganese dioxide, face the problem of oxygen vacancies at the reaction site being replaced by intermediate peroxide species (O2 2- ) or the water molecules that are commonly present in the air and gradually become inactivated. At present, the problem of competitive adsorption between water molecules and ozone molecules has been effectively improved by technical means such as constructing specific water adsorption sites, coating manganese dioxide with a hydrophobic layer, and forming water-resistant oxygen vacancies by chlorine doping. However, manganese-based catalysts still face a severe challenge, that is, the accumulation of intermediate oxygen species on oxygen vacancies causes the ozone decomposition activity to decrease over time. The ozone decomposition reaction is a typical redox reaction, and whether the intermediate oxygen species are easy to desorb determines the stability of the ozone decomposition catalyst. When the oxygen intermediate desorbs, the active site plays the role of an electron acceptor, and the electrons are transferred from the charged oxygen intermediate to the active site. Therefore, it is necessary to develop a catalyst with suitable electron conduction and transfer properties to ensure that the electron reduction reaction of ozone can be achieved in the entire catalytic cycle, and O2 2- At the same time, the catalyst also needs to have a certain degree of water resistance to achieve stable and efficient ozone removal under different humidity conditions.

[0003] It is worth noting that the charged oxygen species O2 2-It can bind to holes in p-type semiconductor materials, effectively accelerating their desorption and conversion. Cuprous oxide and cupric oxide are two naturally occurring copper oxides. Both are highly chemically active, abundant, inexpensive, and non-toxic p-type semiconductors with direct band gaps of approximately 1.2 eV and 2.2 eV, respectively. They are also important materials for applications in heterogeneous catalysis, gas sensors, superconductors, and photovoltaic devices. High activity for ozone decomposition has been observed in cuprous oxide-based catalysts with diverse structures and morphologies. However, cuprous oxide catalysts are easily oxidized during ozone decomposition, and the preparation process is relatively complex. Furthermore, competitive adsorption of water molecules reduces the ozone removal efficiency of cuprous oxide at high humidity. In contrast, cupric oxide has superior chemical stability and redox properties to cuprous oxide at room temperature. However, the currently known ozone removal performance and stability of cupric oxide are poor, and it is easily deactivated in humid conditions, resulting in the limited application of cupric oxide catalysts for ozone removal. Summary of the Invention

[0004] Purpose of the invention: The present invention provides a method for preparing a copper oxide catalyst and its application in catalytic decomposition of ozone, the purpose of which is to solve the problem that traditional catalytic ozone decomposition catalysts are easily deactivated by competitive adsorption of water molecules and accumulation of intermediates, resulting in the catalyst being easily deactivated under humid conditions.

[0005] Technical solution:

[0006] The first aspect of the present invention provides a method for preparing a copper oxide catalyst, comprising the following steps:

[0007] S1. Dissolving copper acetate monohydrate in deionized water to obtain a first solution; dissolving a pH adjuster in deionized water to obtain a second solution;

[0008] S2. The first solution is continuously stirred, and the second solution is added dropwise to the first solution, the pH value of the reaction solution is controlled to be 12-13, and the mixture is stirred at room temperature to obtain a suspension;

[0009] S3, centrifuging the suspension, washing the resulting precipitate with deionized water until the filtrate is neutral, collecting the solid phase by suction filtration, and finally drying to obtain a copper oxide precursor;

[0010] S4. calcining the obtained copper oxide precursor in an air atmosphere at a calcination temperature of 180° C. to 300° C. collecting the solid phase and sieving it to obtain mesoporous nanosheet copper oxide.

[0011] Preferably, in step S1, the concentration of the first solution is 0.1 mol / L to 1 mol / L; the concentration of the second solution is 1 mol / L to 5 mol / L; and the pH regulator is an alkaline regulator.

[0012] Preferably, in step S2, the pH value of the reaction solution is 12.

[0013] Preferably, in step S2, the stirring time at room temperature is 0.5h to 3h.

[0014] Preferably, in step S3, the drying temperature is 60° C. to 120° C., and the drying time is 8 h to 24 h.

[0015] Preferably, in step S4, the calcination time is 1 hour to 5 hours, and the sieving mesh size is 40 mesh to 60 mesh.

[0016] Furthermore, the mesoporous nanosheet copper oxide has a lateral size of 0.1 μm to 1 μm, a thickness of 5 nm to 20 nm, and is rich in mesopores with a mesopore size of 2 nm to 20 nm.

[0017] Furthermore, the XRD characteristic diffraction peaks of the mesoporous nanosheet copper oxide are 2θ=32.5°, 35.5°, 38.7°, 48.7°, 53.5°, 58.3°, 61.5°, 66.3°, 68.1°, 72.4°, 75.2°, and have characteristic crystal planes of CuO {-110}, {002}, {111}, {-202}, {020}, {202}, {-113}, {-311}, {-220}, {311}, {-222}, wherein when the {002} crystal plane with the largest X-ray diffraction intensity is used as a reference, the relative intensities of each crystal plane are: I{-110} / I{002} is 0 .16~0.21, I{111} / I{002} is 0.90~1.02, I{-202} / I{002} is 0.33~0.41, I{020} / I{002} is 0.15~0.21, I{202} / I{002} is 0.21~0.29, I{-113} / I {002} is 0.27~0.39, I{-311} / I{002} is 0.27~0.37, I{-220} / I{002} is 0.25~0.34, I{311} / I{002} is 0.16~0.22, and I{-222} / I{002} is 0.19~0.25.

[0018] The present invention also proposes an application of the copper oxide catalyst prepared by the preparation method in catalytic decomposition of ozone.

[0019] Furthermore, the copper oxide catalyst is subjected to a catalytic reaction for 3 to 30 hours at a temperature of 30° C., a relative humidity of 5% to 80%, and a space velocity of 600 L / g / h, and the catalytic efficiency is at least 99%.

[0020] Beneficial effects:

[0021] Existing methods for preparing mesoporous copper oxide nanosheets include thermal decomposition, hydrothermal / solvothermal methods, electrochemical deposition, and reflux hydrothermal methods. However, these methods all have limitations. Thermal decomposition requires complex precursor preparation; hydrothermal / solvothermal methods require the addition of templates that are difficult to remove and result in poor purity; electrochemical deposition is difficult to scale up, consumes high energy, and has poor practicality; and reflux hydrothermal methods are time-consuming and inefficient. Furthermore, due to the common knowledge that copper oxide has poor ozone catalytic activity, mesoporous copper oxide nanosheets prepared by existing methods have rarely been used in ozone catalysis, or their catalytic activity is poor.

[0022] The present invention utilizes a precipitation reaction of a metallic copper salt under alkaline conditions to generate Cu(OH)2 precursors to varying degrees by adjusting the type of precursor. The reaction state is then controlled by adjusting the pH value of the reaction solution, and the decomposition state of Cu(OH)2 is controlled by calcining at different temperatures to generate copper oxide catalysts with different morphologies and crystal structures. The mesoporous nanosheet copper oxide obtained by this method is a monoclinic copper oxide (JCPDS No. 45-0937) with a space group of C2 / c, free of other impurity phases, and high purity. The strongest diffraction peak belongs to the (002) crystal plane, and the I{111} / I{002} ratio is 0.90 to 1.02. Electron paramagnetic resonance spectroscopy tests show that the copper oxide catalyst prepared by this method has abundant oxygen vacancies. Furthermore, hydrogen temperature-programmed reduction and oxygen temperature-programmed desorption experiments show that the copper oxide catalyst prepared by this method has rapid electron transfer ability, which promotes the dissociation and desorption of the intermediate peroxide species during the ozone decomposition process, thereby avoiding catalyst deactivation caused by the accumulation of intermediates. In addition, the inherent water resistance and enriched pores of the mesoporous nanosheet copper oxide accelerate the dispersion of water molecules on the catalyst surface, thereby achieving high activity and stability of the copper oxide catalyst prepared by the method of the present invention in removing ozone under high humidity conditions.

[0023] The present invention is quick, energy-efficient, and environmentally friendly. The mesoporous nanosheet copper oxide prepared in the present invention, as an ozone decomposition catalyst, efficiently decomposes ozone at high ozone concentrations, high mass space velocities, and a wide humidity range, overcoming the drawback of conventional manganese-based, copper hydroxide, and cuprous oxide catalysts, which are susceptible to deactivation in humid conditions. Under conditions of a temperature of 30°C, a relative humidity of 5% to 80%, and a space velocity of 600 L / g / h, the catalytic reaction proceeds for 3 to 30 hours, achieving a catalytic efficiency of at least 99%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 XRD patterns of copper oxide prepared for Example 1 and Comparative Examples 1 to 4 of the present invention;

[0025] Figure 2The SEM, TEM and HRTEM images of copper oxide prepared in Example 1 of the present invention and Comparative Examples 1-2 are shown;

[0026] Figure 3 EPR spectra of copper oxide prepared in Example 1 and Comparative Examples 1-2 of the present invention;

[0027] Figure 4 H2-TPR and O2-TPD spectra of copper oxide prepared in Example 1 and Comparative Examples 1-2 of the present invention;

[0028] Figure 5 The ozone removal efficiency of the copper oxide prepared in Example 1 of the present invention under different mass space velocity conditions. DETAILED DESCRIPTION

[0029] The present invention is further explained below through specific embodiments. The embodiments are only partial examples of the present invention and do not limit the present invention in any form. That is, the present invention is not limited to the following steps. Equivalent replacement of the raw materials of the present invention or change of the quality of the raw materials are all within the scope of protection of the present invention.

[0030] The present invention provides a method for preparing a copper oxide catalyst for catalytically decomposing ozone, comprising the following steps:

[0031] S1. Dissolve copper acetate monohydrate in deionized water to obtain a first solution of 0.1 mol / L to 1 mol / L; dissolve a pH adjuster in deionized water to obtain a second solution of 1 mol / L to 5 mol / L; the pH adjuster is preferably potassium hydroxide or sodium hydroxide;

[0032] S2. The first solution is continuously stirred, and the second solution is added dropwise to the first solution, the pH value of the reaction solution is controlled to be 12-13, and the mixture is stirred at room temperature for 0.5 h to 3 h to obtain a suspension;

[0033] S3, centrifuging the suspension, washing the resulting precipitate with deionized water until the filtrate is neutral, collecting the solid phase by suction filtration, and finally drying at a temperature of 60°C to 120°C for 8 hours to 24 hours to obtain a copper oxide precursor;

[0034] S4. Place the copper oxide precursor obtained in S3 in a muffle furnace and calcine in an air atmosphere at a calcination temperature of 180°C to 300°C for 1 hour to 5 hours. Collect the solid phase and sieve it through a 40-60 mesh to obtain mesoporous nanosheet copper oxide.

[0035] The present invention can prepare copper oxide with mesoporous nanosheet structure by the above method, such as Figure 1As shown, the XRD characteristic diffraction peaks of the mesoporous nanosheet copper oxide catalyst are 2θ=32.5°, 35.5°, 38.7°, 48.7°, 53.5°, 58.3°, 61.5°, 66.3°, 68.1°, 72.4°, and 75.2°. The crystal planes of CuO are {-110}, {002}, {111}, {-202}, {020}, {202}, {-113}, {-311}, {-220}, {311}, and {-222}. Taking the {002} crystal plane with the largest X-ray diffraction intensity as the reference, the relative intensities of the crystal planes are: I{-110} / I{002} is 0.16 to 0.21, I{111} / I{002} is 0.90 to 1.022, and I{-202} / I{002} is 0.16 to 0.21. is 0.33~0.41, I{020} / I{002} is 0.15~0.21, I{202} / I{002} is 0.21~0.29, I{-113} / I{002} is 0.27~0.39, I{-311} / I{002} is 0.27~0.37, I{-220} / I{002} is 0.25~0.34, I{311} / I{002} is 0.16~0.22, and I{-222} / I{002} is 0.19~0.25. like Figure 2 As shown, the mesoporous nanosheets (CuO-Ac) have a lateral size of 0.1 μm to 1 μm, a thickness of 5 nm to 20 nm, and abundant mesopores with a mesopore size of 2 nm to 20 nm. For ease of comparison, the following examples and comparative examples are based on Example 1 with single-factor substitution.

[0036] Example 1

[0037] This embodiment provides a method for preparing a copper oxide catalyst, comprising the following steps:

[0038] S1. Dissolve 4.04 g of copper acetate monohydrate in 60 mL of deionized water to obtain a first solution; dissolve 16.83 g of potassium hydroxide in 100 mL of deionized water to obtain a second solution;

[0039] S2. Add the second solution dropwise to the first solution, control the pH value of the reaction solution to 12, and stir at room temperature for 1 hour to obtain a suspension;

[0040] S3, centrifuging the suspension, washing the resulting precipitate with deionized water until neutral, and finally drying it in an oven at 85°C overnight to obtain a copper oxide precursor;

[0041] S4. The copper oxide precursor obtained in S3 is placed in a muffle furnace and calcined at 300° C. for 2 h in an air atmosphere to obtain copper oxide, which is recorded as CuO-Ac.

[0042] Example 2

[0043] The difference between this embodiment and embodiment 1 is that S2 is used to control the pH value of the reaction solution to 13; other conditions are exactly the same as those in embodiment 1; and the obtained copper oxide is recorded as CuO-13.

[0044] Example 3

[0045] This embodiment provides a method for preparing a copper oxide catalyst, comprising the following steps:

[0046] S1. Dissolve 4.04 g of copper acetate monohydrate in 60 mL of deionized water to obtain a first solution; dissolve 16.83 g of potassium hydroxide in 100 mL of deionized water to obtain a second solution;

[0047] S2. Add the second solution dropwise to the first solution, control the pH value of the reaction solution to 12, and stir at room temperature for 1 hour to obtain a suspension;

[0048] S3, centrifuging the suspension, washing the resulting precipitate with deionized water until neutral, and finally drying it in an oven at 85°C overnight to obtain a copper oxide precursor;

[0049] S4. The copper oxide precursor obtained in S3 is placed in a muffle furnace and calcined at 180° C. for 2 h in an air atmosphere to obtain copper oxide, which is recorded as CuO-180.

[0050] Example 4

[0051] The difference between this embodiment and embodiment 3 is that S4 is calcined at 200° C. in an air atmosphere; other conditions are exactly the same as those in embodiment 3; and the obtained copper oxide is recorded as CuO-200.

[0052] Example 5

[0053] The difference between this embodiment and embodiment 3 is that S4 is calcined at 250° C. in an air atmosphere; other conditions are exactly the same as those in embodiment 3; and the obtained copper oxide is recorded as CuO-250.

[0054] Comparative Example 1

[0055] This comparative example is commercial copper oxide purchased from Sinopharm Chemical Reagent Co., Ltd., denoted as CuO-C. Based on the {002} crystal plane, I{111} / I{002} is 1.0857.

[0056] Comparative Example 2

[0057] This comparative example differs from Example 1 in that S1 comprises dissolving 4.89 g of copper nitrate trihydrate in 60 mL of deionized water to obtain a first solution. All other conditions are identical to those in Example 1. The resulting copper oxide is designated as CuO-N. Based on the {002} plane, which exhibits the highest X-ray diffraction intensity, I{111} / I{002} is 0.9461.

[0058] Comparative Example 3

[0059] This comparative example differs from Example 1 in that S1 comprises dissolving 3.45 g of copper chloride dihydrate in 60 mL of deionized water to obtain a first solution. All other conditions are identical to those in Example 1. The resulting copper oxide is designated as CuO-Cl. Based on the {002} plane, which exhibits the highest X-ray diffraction intensity, I{111} / I{002} is 1.0444.

[0060] Comparative Example 4

[0061] This comparative example differs from Example 1 in that S1 comprises dissolving 5.05 g of copper sulfate pentahydrate in 60 mL of deionized water to obtain a first solution. All other conditions are identical to those in Example 1. The resulting copper oxide is designated as CuO-S. Based on the {002} plane, which exhibits the highest X-ray diffraction intensity, I{111} / I{002} is 0.7511.

[0062] Comparative Example 5

[0063] The difference between this comparative example and Example 1 is that S2 is used to control the pH value of the reaction solution to 8; other conditions are exactly the same as those in Example 1; and the obtained copper oxide is recorded as CuO-8.

[0064] Comparative Example 6

[0065] The difference between this comparative example and Example 1 is that S2 is used to control the pH value of the reaction solution to 10; other conditions are exactly the same as those in Example 1; and the obtained copper oxide is recorded as CuO-10.

[0066] Comparative Example 7

[0067] The difference between this comparative example and Example 1 is that S2 is used to control the pH value of the reaction solution to 14; other conditions are exactly the same as those in Example 1; and the obtained copper oxide is recorded as CuO-14.

[0068] Comparative Example 8

[0069] The difference between this comparative example and Example 3 is that S4 is calcined at 400° C. in an air atmosphere; other conditions are exactly the same as those in Example 3; and the obtained copper oxide is recorded as CuO-400.

[0070] Comparative Example 9

[0071] The difference between this comparative example and Example 1 is that S4 is calcined at 500° C. in an air atmosphere; other conditions are exactly the same as those in Example 1; and the obtained copper oxide is recorded as CuO-500.

[0072] Next, the catalysts described in Examples 1 to 5 and Comparative Examples 1 to 9 were tested for their performance in catalytic decomposition of ozone. The test methods and conditions are as follows:

[0073] The activity evaluation test conditions are as follows: ozone concentration in the reaction gas is 45 ppm, temperature is 30°C, relative humidity is 80%, test air velocity is 600 L / g / h, and test time is 3 hours. The ozone conversion rate comparison table corresponding to each example is recorded and prepared as shown in Table 1.

[0074] Table 1 Comparison table of ozone conversion rates of various examples

[0075]

[0076] As can be seen from Table 1 above, the copper oxide catalysts prepared according to the present invention have excellent catalytic decomposition capabilities of ozone. Under conditions of a temperature of 30°C, a relative humidity of 80%, and a space velocity of 600 L / g / h, after a catalytic reaction for 3 hours, the catalytic efficiencies of Examples 1 to 5 all exceeded 99%. Specifically, the mesoporous nanosheet copper oxide catalyst of Example 1 maintained a catalytic efficiency exceeding 90% even after a catalytic reaction for 3 hours under conditions of a temperature of 30°C, a relative humidity of 80%, and a high space velocity of 1200 L / g / h.

[0077] like Figure 1 From the XRD patterns of Example 1 and Comparative Examples 1 to 4, it can be seen that the copper oxide prepared by the present invention and the commercial copper oxide (CuO-C) of Comparative Example 1 are both copper oxides with a monoclinic structure (JCPDS No. 45-0937), a space group of C2 / c, no other impurity phases, and high purity. In contrast, among the copper oxides prepared by the present invention, the XRD diffraction peak of Example 1 (CuO-Ac) is the strongest, and the difference in diffraction peak intensity from that of commercial copper oxide is not much, indicating that it has the highest crystallinity. In addition, the strongest diffraction peak of commercial copper oxide belongs to the (111) crystal plane, while the strongest diffraction peak of Example 1 belongs to the (002) crystal plane, indicating that CuO-Ac mainly grows along the (002) crystal plane during the growth process. Combined with the activity data in Table 1, it can be seen that the type of precursor has an important influence on the catalytic performance of the prepared copper oxide ozone catalyst. Taking the most active Example 1 (CuO-Ac), Comparative Example 2 (CuO-N) and the essentially inactive commercial copper oxide of Comparative Example 1 as examples, the effect of the type of precursor on the morphology and structure of the copper oxide ozone catalyst was explored. Figure 2As shown, copper oxide prepared from copper acetate or copper nitrate as precursors exhibits nanosheet and nanoparticle morphologies, respectively, demonstrating high catalytic performance in ozone decomposition. Commercial copper oxide, on the other hand, exhibits an irregular polygonal shape and is much larger than CuO-Ac and CuO-N, lacking any ability to catalyze ozone decomposition. Furthermore, the abundant irregular pores within the CuO-Ac nanosheet structure facilitate the transport and diffusion of ozone molecules, water molecules, intermediates, and products, significantly improving ozone removal performance.

[0078] Copper oxide prepared from copper acetate as a precursor also has abundant oxygen vacancies. Figure 3 As shown in the figure, the three samples CuO-Ac, CuO-N and CuO-C all show a symmetrical signal at a g value of 2.001, which can be considered as electrons trapped in oxygen vacancies. The signal intensity of CuO-Ac is significantly stronger than that of CuO-N and CuO-C, indicating that a large number of oxygen vacancies are generated in the CuO-Ac catalyst, which as active sites are conducive to the adsorption and decomposition of ozone. On the other hand, CuO-Ac exhibits strong electron transfer ability. Figure 4 As shown in the hydrogen temperature-programmed reduction and oxygen temperature-programmed desorption experiments, CuO-Ac underwent redox reaction and lattice oxygen migration at lower temperatures, respectively, further demonstrating its high electron transfer ability, thereby achieving nearly 100% ozone removal efficiency at high relative humidity and high space velocity.

[0079] During the synthesis of the catalyst, the precursor decomposes to form new bonds, and then forms a new crystal structure or morphology. Even the slightest change will affect the formation of the metastable phase. The anions in the solution prepared from different precursors have a decisive influence on the formation of the crystal structure and morphology of copper oxide. The crystal phase of copper oxide is closely related to the type of anions in the precursor and their chemical coordination ability. During the crystal formation process, acetate ions (CH3COO - ), nitrate ions (NO3 - ), chloride ion (Cl - ) and sulfate ions (SO4 2- ) for copper ions (Cu 2+ ) have different affinities, which affects the formation of CuO units and ultimately produces copper oxides with different structures, morphologies and properties, showing different catalytic decomposition abilities of ozone.

[0080] As shown in Table 1, comparing Examples 1 to 2 with Comparative Examples 5 to 7, when the precursors are all copper acetate, the pH of the reaction solution in the preparation method has a significant impact on the catalytic performance of the resulting ozone catalyst. As the pH value increases from 8 to 13, the ozone removal efficiency of the copper oxide catalyst gradually increases. When the pH value further increases to 14, the activity of copper oxide decreases. Specifically, copper oxide has the highest and similar activity at pH values ​​of 12 and 13, both achieving ozone removal efficiencies exceeding 99%.

[0081] Achieving a pH of 12 requires approximately 20 mL of KOH solution, while achieving a pH of 13 requires nearly 40 mL. Therefore, in practical applications, a pH of 12 is optimally controlled to ensure high conversion rates while conserving raw materials.

[0082] Table 1 shows that the calcination temperature of the copper oxide precursor also has a certain impact on the catalytic performance of the resulting ozone catalyst, as can be seen from a comparison of Example 1, Examples 3 to 5, and Comparative Examples 8 to 9. When the calcination temperature is between 180°C and 300°C (200°C, 250°C), the resulting copper oxide catalyst exhibits excellent ozone removal performance, achieving an ozone removal efficiency of over 99%. However, when the calcination temperature is further increased, the activity decreases slightly (400°C, 97.17%), but the ozone conversion rate remains high. Furthermore, when the temperature is increased excessively to 500°C (Comparative Example 9), the ozone removal activity of the resulting copper oxide catalyst decreases significantly.

[0083] Furthermore, the stability test and humidity effect test of the catalyst were conducted: in order to ensure the stability of the catalyst, the catalyst in Example 1 was used as an example (all catalysts prepared by the method of the present invention have the same or similar technical effects and are not repeated here). The ozone conversion rate corresponding to the test time of 3h to 30h and the ozone conversion rate under different humidity were recorded. The relative humidity of the stability test was 5% to 80%. Other test conditions were the same as those in the activity evaluation test. The results are shown in Table 2 below.

[0084] Table 2: Ozone conversion rate of the catalyst of Example 1

[0085]

[0086] The catalyst stability test results in Table 2 above demonstrate that the mesoporous nanosheet copper oxide catalyst of the present invention exhibits high stability and is capable of stable and efficient ozone decomposition over long periods of time in high humidity environments. This catalyst can be used for the efficient and long-term decomposition of ozone and the treatment of various ozone-containing gases. Furthermore, the catalyst of the present invention achieves an ozone decomposition conversion rate exceeding 99% across a wide relative humidity range of 5% to 80%, demonstrating that the mesoporous nanosheet copper oxide catalyst of the present invention maintains high ozone conversion efficiency across a wide range of relative humidity conditions.

[0087] The stability of the mesoporous nanosheet copper oxide catalyst (Example 1) was further tested under harsh conditions of high space velocity (relative humidity of 60%). Figure 5 As shown in Figure 2, the activity of the copper oxide catalyst gradually decreased with increasing mass space velocity. Notably, after an initial short-term decrease, the activity subsequently remained stable. Even at an ultra-high space velocity of 3000 L / g / h, the ozone removal efficiency of the mesoporous nanosheet copper oxide catalyst remained at approximately 66% for 3 hours, demonstrating the excellent stability of the copper oxide catalyst.

[0088] In summary, the mesoporous nanosheet copper oxide catalyst prepared in the present invention has the advantages of high activity, low cost, and good water resistance. It is easy to use in practice and will not introduce other pollutants. It has important practical value for effectively removing ozone pollution in indoor air.

[0089] The contents of the above embodiments should be understood as being only used to more clearly illustrate the present invention and not to limit the scope of the present invention. Various equivalent modifications of the present invention made by those skilled in the art fall within the scope defined by the claims appended to this application.

Claims

1. A method for preparing a copper oxide catalyst, characterized in that: Here are the steps: S1. Dissolving copper acetate monohydrate in deionized water to obtain a first solution; dissolving a pH adjuster in deionized water to obtain a second solution; S2. The first solution is continuously stirred, and the second solution is added dropwise to the first solution, the pH value of the reaction solution is controlled to be 12-13, and the mixture is stirred at room temperature to obtain a suspension; S3, centrifuging the suspension, washing the resulting precipitate with deionized water until the filtrate is neutral, collecting the solid phase by suction filtration, and finally drying to obtain a copper oxide precursor; S4, calcining the obtained copper oxide precursor in an air atmosphere at a calcination temperature of 180° C. to 300° C., collecting the solid phase and sieving it to obtain mesoporous nanosheet copper oxide; The mesoporous nanosheet copper oxide has a lateral size of 0.1 μm to 1 μm, a thickness of 5 nm to 20 nm, and a mesopore size of 2 nm to 20 nm. The mesoporous nanosheet copper oxide is a copper oxide with a monoclinic structure, conforms to the XRD standard card JCPDS No. 45-0937, has a space group of C2 / c, has no other impurity phases, and the strongest diffraction peak belongs to the (002) crystal plane and I{111} / I{002} is 0.90 to 1.

02.

2. The method for preparing a copper oxide catalyst according to claim 1, wherein In step S1 , the concentration of the first solution is 0.1 mol / L to 1 mol / L; the concentration of the second solution is 1 mol / L to 5 mol / L; and the pH regulator is an alkaline regulator.

3. The method for preparing the copper oxide catalyst according to claim 1, wherein In step S2, the pH value of the reaction solution is 12.

4. The method for preparing a copper oxide catalyst according to claim 1, wherein In step S2, the stirring time at room temperature is 0.5h to 3h.

5. The method for preparing the copper oxide catalyst according to claim 1, wherein In step S3, the drying temperature is 60° C. to 120° C., and the drying time is 8 hours to 24 hours.

6. The method for preparing a copper oxide catalyst according to claim 1, wherein: In step S4, the calcination time is 1 hour to 5 hours, and the sieving mesh size is 40 mesh to 60 mesh.

7. The method for preparing a copper oxide catalyst according to claim 1, wherein: The XRD characteristic diffraction peaks of the mesoporous nanosheet copper oxide are 2θ=32.5°, 35.5°, 38.7°, 48.7°, 53.5°, 58.3°, 61.5°, 66.3°, 68.1°, 72.4°, and 75.2°, and the mesoporous nanosheet copper oxide has characteristic crystal planes {-110}, {002}, {111}, {-202}, {020}, {202}, {-113}, {-311}, {-220}, {311}, and {-222} of CuO, wherein when the {002} crystal plane with the largest X-ray diffraction intensity is used as a reference, the relative intensities of the crystal planes are: I{-110} / I{002} is 0.16 ~0.21, I{111} / I{002} is 0.90~1.02, I{-202} / I{002} is 0.33~0.41, I{020} / I{002} is 0.15~0.21, I{202} / I{002} is 0.21~0.29, I{-113} / I{ 002} is 0.27~0.39, I{-311} / I{002} is 0.27~0.37, I{-220} / I{002} is 0.25~0.34, I{311} / I{002} is 0.16~0.22, and I{-222} / I{002} is 0.19~0.

25.

8. Use of a copper oxide catalyst prepared by the preparation method according to any one of claims 1 to 7 in catalytic decomposition of ozone.

9. The use in catalytic decomposition of ozone according to claim 8, characterized in that: The copper oxide catalyst is subjected to catalytic reaction for 3 to 30 hours under the conditions of a temperature of 30° C., a relative humidity of 5 to 80%, and a space velocity of 600 L / g / h, and the catalytic efficiency is at least 99%.

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