Formaldehyde decomposition catalyst, preparation method, use method and application thereof, and room-temperature formaldehyde removal product
The nano-AgMnO2 catalyst is loaded through molecular sieve, and the high active surface is exposed using the copper-manganese ore structure, which solves the problems of low formaldehyde purification efficiency and high cost in the prior art, and achieves efficient and stable formaldehyde decomposition effect.
Patent Information
- Application Number
- CN202510661410.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-22
- Publication Date
- 2025-08-01
AI Technical Summary
The existing formaldehyde purification technology is difficult to continuously degrade formaldehyde continuously, and precious metal catalysts are costly and difficult to produce industrially. The removal rate of manganese cerium oxide catalysts is low and the selectivity is poor.
The nano-AgMnO2 catalyst was prepared by impregnation, drying, calcining and ozone treatment. The nano-AgMnO2 with the copper-manganese ore structure was exposed to the high-active surface, and formaldehyde was enriched with adsorption of molecular sieve for room temperature catalytic oxidation.
It achieves 100% conversion rate of formaldehyde and 100% carbon dioxide selectivity, avoids the generation of intermediate products, reduces production costs, is suitable for industrial applications, and has a long catalyst life.
Smart Images
Figure CN120394073A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of gas purification, and in particular to a formaldehyde decomposition catalyst, a preparation method, a use method and an application thereof, and a room temperature formaldehyde removal product. Background Art
[0002] At present, the phenomenon of excessive formaldehyde concentration in the indoor environment is relatively common. Formaldehyde pollution can cause great harm to people's physical and mental health. The sources of formaldehyde are extensive, covering multiple aspects such as clothing, food, housing, and transportation, and its release period is as long as 10 to 15 years, which poses a huge challenge to the treatment of formaldehyde pollution. The existing formaldehyde purification technologies mainly include activated carbon adsorption technology, photocatalyst technology and plasma technology, but these technologies all have the problem of being difficult to continuously degrade formaldehyde, so it is difficult to be used as an effective formaldehyde degradation technology.
[0003] In recent years, the room temperature catalytic oxidation technology has been considered the most potential formaldehyde purification technology because it can completely catalytically oxidize formaldehyde into water and carbon dioxide at room temperature without additional conditions. However, currently, the catalysts capable of removing formaldehyde at room temperature are mainly platinum-based noble metal catalysts, and these catalysts have problems such as high price and difficulty in popularization and application. In addition, manganese-cerium series catalysts for removing formaldehyde at room temperature have also been developed. The development of this manganese-cerium oxide catalyst provides a new idea for the room temperature catalytic oxidation technology. However, the preparation method of this catalyst requires the use of a plasma discharge device, which has high requirements for equipment and harsh calcination conditions, and is not conducive to industrial production; at the same time, the removal rate of formaldehyde by this catalyst is low, and the selectivity of the catalytic reaction is not good.
[0004] In view of this, the present invention is specifically proposed. Summary of the Invention
[0005] The purpose of the present invention is to provide a formaldehyde decomposition catalyst, a preparation method, a use method and an application thereof, and a room temperature formaldehyde removal product to alleviate at least one of the above technical problems in the prior art.
[0006] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:
[0007] The first aspect of the present invention provides a formaldehyde decomposition catalyst, which includes molecular sieve and nano-AgMnO2 loaded on the molecular sieve; the nano-AgMnO2 has a spinel structure.
[0008] Further, the content of the nano-AgMnO2 is 1.0 to 10.0 wt%, preferably 5.0 to 8.0 wt%.
[0009] Further, the silica-alumina ratio of the molecular sieve is 10 to 1000.
[0010] Preferably, the molecular sieve includes zeolite molecular sieve.
[0011] Preferably, the zeolite molecular sieve includes at least one of ZSM-5 molecular sieve, β molecular sieve and mordenite molecular sieve.
[0012] The second aspect of the present invention provides a method for preparing the formaldehyde decomposition catalyst, which is to immerse the molecular sieve in a solution containing a silver source and a manganese source, and after completion, dry, calcine and ozone-treat to obtain the formaldehyde decomposition catalyst.
[0013] Furthermore, in the solution containing a silver source and a manganese source, the silver source includes silver oxide; the manganese source includes manganese oxide.
[0014] Preferably, in the solution containing a silver source and a manganese source, the concentration of silver oxide is 1-10 wt%; the concentration of manganese oxide is 1-10 wt%.
[0015] Preferably, the impregnation time is 1-2 h.
[0016] Preferably, the drying temperature is 80-120 °C.
[0017] Preferably, the calcination temperature is 300-400 °C and the time is 4-6 h.
[0018] Furthermore, the process of ozone treatment is: at a temperature of 20-30 °C, use ozone with a concentration of 50-100 ppm for treatment, and the volume space velocity is 500000-800000 h -1 , and the treatment time is 1-2 h.
[0019] The third aspect of the present invention provides a method for using the formaldehyde decomposition catalyst, which is to place the formaldehyde decomposition catalyst in a gas containing formaldehyde for reaction to remove formaldehyde.
[0020] Furthermore, in the gas containing formaldehyde, the formaldehyde concentration ≤ 100 ppm, and the space velocity
[0021] ≤ 100 L / (g·h).
[0022] Preferably, the humidity of the gas containing formaldehyde is 50-95%.
[0023] The fourth aspect of the present invention provides the application of the formaldehyde decomposition catalyst in removing formaldehyde at room temperature.
[0024] The fifth aspect of the present invention provides a room temperature formaldehyde removal product, which includes the formaldehyde decomposition catalyst.
[0025] Compared with the prior art, the present invention has at least the following beneficial effects:
[0026] The present invention provides a formaldehyde decomposition catalyst, wherein nano-AgMnO2 with a copper-manganese ore structure is used to maximize the exposure of the (100) facet, thereby increasing the migration capacity of active oxygen. The molecular sieve is conducive to the adsorption and enrichment of formaldehyde. The combination of the two enables the formaldehyde adsorbed on the catalyst surface to rapidly react with the active oxygen, mineralizing it to generate non-toxic and harmless carbon dioxide and water, achieving the purpose of decomposing formaldehyde. The catalyst consistently maintains 100% selectivity for carbon dioxide and a formaldehyde conversion rate of 100%, demonstrating excellent selectivity and removal efficiency. No intermediate products are generated during the reaction, avoiding secondary pollution, making it an ideal formaldehyde decomposition catalyst.
[0027] The method for preparing a formaldehyde decomposition catalyst provided by the present invention comprises four steps: impregnation, drying, calcination, and ozone treatment. The process is concise and easy to operate, eliminating the need for complex equipment and tedious steps. This reduces production costs, facilitates production, and is suitable for large-scale industrial applications. After drying, calcination, and ozone treatment, the catalyst's structure becomes more stable, maintaining efficient catalytic performance for an extended period and extending its service life.
[0028] The method for using the formaldehyde decomposition catalyst provided by the present invention, in view of the advantages of the above-mentioned formaldehyde decomposition catalyst, makes the use of the catalyst more convenient and can be widely applied in various scenarios, showing extremely high practicality and flexibility.
[0029] The formaldehyde decomposition catalyst provided by the present invention has demonstrated excellent performance and wide applicability in the application of indoor air, industrial exhaust, automobile interior odor treatment, and other formaldehyde-contaminated places, and has important practical application value and market promotion potential.
[0030] The room-temperature formaldehyde removal product provided by the present invention, in view of the advantages of the above-mentioned formaldehyde decomposition catalyst, can be made into various products according to the place of use and user preferences, showing extremely high flexibility and wide applicability, and has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0032] Figure 1 This is a transmission electron micrograph of the formaldehyde decomposition catalyst obtained in Example 1;
[0033] Figure 2TEM image of the formaldehyde decomposition catalyst obtained in Example 2;
[0034] Figure 3 TEM image of the formaldehyde decomposition catalyst obtained in Example 3;
[0035] Figure 4 Standard structure diagram of cryptomelane. Detailed implementation manners
[0036] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention.
[0037] In the following text, the terms "comprising", "having" and their cognates that can be used in various embodiments of the present invention are only intended to represent specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be construed as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.
[0038] The first aspect of the present invention provides a formaldehyde decomposition catalyst, which includes a molecular sieve and nano-AgMnO₂ supported on the molecular sieve; the nano-AgMnO₂ has a cryptomelane structure.
[0039] For the formaldehyde decomposition catalyst provided by the present invention, the use of nano-AgMnO₂ with a cryptomelane structure can maximize the exposure of the (100) plane, thereby increasing the migration ability of active oxygen and having good formaldehyde elimination ability; the molecular sieve is beneficial to the adsorption and enrichment of formaldehyde. The combination of the two can enable the formaldehyde adsorbed on the catalyst surface to quickly react with active oxygen and mineralize to generate non-toxic and harmless carbon dioxide and water, achieving the purpose of decomposing formaldehyde. The selectivity of this catalyst for carbon dioxide always remains at 100%, and the formaldehyde conversion rate can also reach 100%, showing excellent selectivity and removal efficiency, and no intermediate products are generated during the reaction, avoiding secondary pollution. It is an ideal formaldehyde decomposition catalyst.
[0040] Compared with traditional formaldehyde removal materials that rely on adsorption, the formaldehyde decomposition catalyst provided by the present invention does not have problems such as limited adsorption capacity and adsorption saturation, has high removal efficiency, long service life, and can achieve long-term formaldehyde removal.
[0041] Furthermore, the content of the nano-AgMnO₂ is 1.0 - 10.0 wt%, preferably 5.0 - 8.0 wt%.
[0042] When the content of nano-AgMnO2 is higher than 10.0 wt%, the dispersion degree of nano-AgMnO2 will be reduced, resulting in a decrease in catalytic activity; when the content of nano-AgMnO2 is lower than 1.0 wt%, the catalytic efficiency is low.
[0043] Typical but non-limiting, in the formaldehyde decomposition catalyst, the content of nano-AgMnO2 can be, for example, 10.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt% or 10.0 wt%, and can also be any value within the range of 1.0 wt% to 10.0 wt%; preferably, the content of nano-AgMnO can be 5.0 wt%, 6.0 wt%, 7.0 wt% or 8.0 wt%, and can also be any value within the range of 5.0 wt% to 8.0 wt%.
[0044] Furthermore, the silica-alumina ratio of the molecular sieve is 10 to 1000.
[0045] Typical but non-limiting, the silica-alumina ratio of the molecular sieve can be, for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900 or 1000, and can also be any value within the range of 10 to 1000.
[0046] Preferably, the molecular sieve includes zeolite molecular sieve.
[0047] Preferably, the zeolite molecular sieve includes at least one of ZSM-5 molecular sieve, β molecular sieve and mordenite molecular sieve.
[0048] The second aspect of the present invention provides a preparation method of the formaldehyde decomposition catalyst, which is to impregnate the molecular sieve in a solution containing a silver source and a manganese source, and after completion, dry, calcine and ozone-treat to obtain the formaldehyde decomposition catalyst.
[0049] The preparation method of the formaldehyde decomposition catalyst provided by the present invention has four steps: impregnation, drying, calcination and ozone treatment. The process flow is simple, easy to operate, does not require complex equipment and cumbersome steps, reduces production costs, is easy to produce by the method, and is suitable for large-scale industrial applications. After the catalyst is dried, calcined and ozone-treated, the structure of the catalyst is more stable, and it can maintain high catalytic performance for a long time, extending the service life of the catalyst.
[0050] Furthermore, in the solution containing a silver source and a manganese source, the silver source includes silver oxide; the manganese source includes manganese oxide.
[0051] Preferably, in the solution containing a silver source and a manganese source, the concentration of silver oxide is 1-10 wt%; the concentration of manganese oxide is 1-10 wt%.
[0052] Preferably, the impregnation time is 1-2 h. During the impregnation process, the silver source and the manganese source adhere to the surface of the molecular sieve, and highly dispersed nano-AgMnO₂ with a pyrolusite structure is in-situ synthesized through subsequent calcination and ozone treatment. Due to in-situ synthesis, highly dispersed nano-AgMnO₂ is obtained, and at the same time, the exposed crystal planes are maximally the highly active (100) planes.
[0053] Typically but not restrictively, the impregnation time can be, for example, 1 h, 1.5 h or 2 h, or any value within the range of 1 h to 2 h.
[0054] Preferably, the drying temperature is 80-120 °C.
[0055] Typically but not restrictively, the drying temperature can be, for example, 80 °C, 90 °C, 100 °C, 110 °C or 120 °C, or any value within the range of 80 °C to 120 °C.
[0056] Preferably, the calcination temperature is 300-400 °C and the time is 4-6 h.
[0057] Typically but not restrictively, the calcination temperature can be, for example, 300 °C, 320 °C, 340 °C, 360 °C, 380 °C or 400 °C, or any value within the range of 300 °C to 400 °C; the calcination time can be, for example, 4 h, 5 h or 6 h, or any value within the range of 4 h to 6 h.
[0058] Furthermore, the ozone treatment process is as follows: at a temperature of 20-30 °C, ozone with a concentration of 50-100 ppm is used for treatment, and the volume space velocity is 500000-800000 h -1 , and the treatment time is 1-2 h.
[0059] Typically but not restrictively, the ozone treatment process is as follows: at a temperature of 20 °C to 30 °C, ozone with a concentration of 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm or 100 ppm is used for treatment, and the volume space velocity is 500000 h -1 、600000 h -1 or 800000 h -1 , and the treatment time is 1 h, 1.5 h or 2 h, or any value within the range of 1 h to 2 h.
[0060] It should be noted that the volumetric space-time rate refers to the flow rate of ozone flowing through the catalyst bed, which is 500,000 - 800,000 h -1 per hour. The ozone of 1 unit volume passes through 1 unit volume of the catalyst volume. Here, the catalyst refers to the formaldehyde decomposition catalyst that has not been treated with ozone.
[0061] The third aspect of the present invention provides a method for using the formaldehyde decomposition catalyst, which places the formaldehyde decomposition catalyst in a gas containing formaldehyde for reaction to remove formaldehyde.
[0062] Regarding the advantages of the formaldehyde decomposition catalyst provided by the present invention, the use of this catalyst is more convenient, and it can be widely applied to various scenarios, showing extremely high practicality and flexibility.
[0063] Furthermore, in the gas containing formaldehyde, the formaldehyde concentration ≤ 100 ppm, and the space velocity
[0064] ≤ 100 L / (g·h), preferably 50 - 100 L / (g·h), more preferably 50 - 60 L / (g·h).
[0065] Typical but non-limiting, in the gas containing formaldehyde, the formaldehyde concentration can be, for example, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm or 100 ppm, or any value within the range of 100 ppm and below. In order to maintain better formaldehyde removal efficiency, the formaldehyde concentration can be adjusted within the above range.
[0066] It should be noted that the space velocity of the gas refers to the flow rate of the gas containing formaldehyde flowing through the catalyst. Typical but non-limiting, the space velocity of the gas can be, for example, 10 L / (g·h), 20 L / (g·h), 30 L / (g·h), 40 L / (g·h), 50 L / (g·h), 60 L / (g·h), 70 L / (g·h), 80 L / (g·h), 90 L / (g·h) or 100 L / (g·h), or any value within the range of 100 L / (g·h) and below, which can ensure the reaction efficiency.
[0067] Preferably, the humidity of the gas containing formaldehyde is 50 - 95%.
[0068] Typical but non-limiting, the humidity of the gas containing formaldehyde can be, for example, 50%, 60%, 70%, 80%, 90% or 95%, or any value within the range of 50% to 95%.
[0069] The fourth aspect of the present invention provides the application of the formaldehyde decomposition catalyst in removing formaldehyde at room temperature.
[0070] The application of the formaldehyde decomposition catalyst provided by the present invention demonstrates excellent performance and wide applicability whether it is for indoor air, industrial tail gas, treatment of peculiar smell in automobile interiors, or other formaldehyde-polluted places, and has important practical application value and market promotion potential.
[0071] The room temperature mentioned herein refers to the temperature range of 20 - 25 °C.
[0072] The fifth aspect of the present invention provides a room temperature formaldehyde removal product, which includes the formaldehyde decomposition catalyst described above.
[0073] Due to the advantages of the formaldehyde decomposition catalyst described above, the room temperature formaldehyde removal product provided by the present invention can be made into various products according to the usage place and user preferences, showing extremely high flexibility and wide applicability, and having broad market prospects.
[0074] In the specific implementation process, the room temperature formaldehyde removal product can be made into a formaldehyde removal package, a formaldehyde removal net, a formaldehyde removal box, or the formaldehyde decomposition catalyst can be integrated into an air purifier, or the formaldehyde decomposition catalyst can be loaded on some felt materials to increase the contact area.
[0075] The present invention will be further illustrated by specific examples and comparative examples below. However, it should be understood that these examples are only for more detailed illustration and should not be construed as limiting the present invention in any form. For the raw materials used in the examples and comparative examples of the present invention, those without specific conditions indicated are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments without the manufacturer indicated, they are all conventional products that can be obtained through commercial purchase.
[0076] Example 1
[0077] This example provides a formaldehyde decomposition catalyst, and the preparation process is as follows:
[0078] 1. Add ZSM-5 molecular sieve (silica-alumina ratio is 1000) to a solution containing silver oxide (content 1 wt%) and manganese oxide (content 10 wt%), mix evenly, and stir for 1 hour.
[0079] 2. Filter the solution, dry the obtained solid at 120 °C and then calcine it at 400 °C for 4 hours. Finally, treat it with ozone at a concentration of 50 ppm at 30 °C for 1 h, and the volume space velocity is 500000 h -1 , to obtain a nano-AgMnO₂ catalyst with a spinel structure supported on ZSM-5 molecular sieve.
[0080] Example 2
[0081] This embodiment provides a formaldehyde decomposition catalyst, and the preparation process is as follows:
[0082] 1. Add β-zeolite (silica-alumina ratio of 10) to a solution containing silver oxide (content 10 wt%) and manganese oxide (content 1 wt%), mix evenly, and stir for 2 hours.
[0083] 2. Filter the solution, dry the obtained solid at 80 °C and then calcine it at 300 °C for 6 hours. Finally, treat it with ozone at a concentration of 100 ppm at 20 °C for 2 h, and the volume space velocity is 800000 h -1 , to obtain a nano-AgMnO₂ catalyst with a spinel structure supported on β-zeolite.
[0084] Example 3
[0085] This embodiment provides a formaldehyde decomposition catalyst, and the preparation process is as follows:
[0086] 1. Add mordenite (silica-alumina ratio of 30) to a solution containing silver oxide (content 5 wt%) and manganese oxide (content 5 wt%), mix evenly, and stir for 1.5 hours.
[0087] 2. Filter the solution, dry the obtained solid at 100 °C and then calcine it at 350 °C for 5 hours. Finally, treat it with ozone at a concentration of 70 ppm at 25 °C for 1.5 h, and the volume space velocity is 700000 h -1 , to obtain a nano-AgMnO₂ catalyst with a spinel structure supported on mordenite.
[0088] Example 4
[0089] This embodiment provides a formaldehyde decomposition catalyst. The difference from Example 1 is that ZSM-5 zeolite with a silica-alumina ratio of 100 is used to replace ZSM-5 zeolite with a silica-alumina ratio of 1000, and the remaining raw materials and preparation methods are the same as those in Example 1, which will not be elaborated here.
[0090] Example 5
[0091] This embodiment provides a formaldehyde decomposition catalyst. The difference from Example 1 is that ZSM-5 zeolite with a silica-alumina ratio of 10 is used to replace ZSM-5 zeolite with a silica-alumina ratio of 1000, and the remaining raw materials and preparation methods are the same as those in Example 1, which will not be elaborated here.
[0092] Example 6
[0093] This embodiment provides a formaldehyde decomposition catalyst. The difference from Example 1 is that ozone treatment is carried out directly without calcination, and the remaining raw materials and preparation methods are the same as those in Example 1, which will not be elaborated here.
[0094] Example 7
[0095] This example provides a formaldehyde decomposition catalyst, which is different from that of Example 1 in that no ozone treatment is carried out, and the remaining raw materials and preparation methods are the same as those of Example 1, so they will not be elaborated here.
[0096] Comparative Example 1
[0097] This comparative example provides an AgMnO2 catalyst, and the preparation process is as follows:
[0098] 1. Mix an aqueous solution containing 1 mol of manganese nitrate, an aqueous solution of 1 mol of silver nitrate with 0.05 mol of ethylene glycol, and stir and reflux at 120 °C for 24 hours. Evaporate the obtained gel to dryness at 120 °C and calcine it at 400 °C for 4 hours to obtain the AgMnO2 catalyst.
[0099] Comparative Example 2
[0100] This comparative example provides a formaldehyde decomposition catalyst, and the preparation process is as follows: Add 10 g of the AgMnO2 catalyst synthesized in Comparative Example 1 and 100 g of ZSM-5 molecular sieve (silica-alumina ratio of 1000) to an ethylene glycol solution, mix them, stir and heat, evaporate the solvent, and calcine the obtained solid at 400 °C for 4 hours to obtain the formaldehyde decomposition catalyst.
[0101] Characterization Example
[0102] The formaldehyde decomposition catalysts obtained in Examples 1-3 were subjected to transmission electron microscopy, and the corresponding transmission electron micrographs are as Figure 1 、 Figure 2 and Figure 3 shown.
[0103] From Figures 1 - 3 it can be seen that the lattice diagram of the catalyst is consistent with the Figure 4 standard structure of the cupric manganese ore provided; the particle size of AgMnO2 is 5-10 nm; the exposed crystal planes are all (100) crystal planes; the lattice spacing is Figure 1
[0104] Test Example 1
[0105] The catalysts obtained in the examples and comparative examples were subjected to AgMnO2 content determination, and the data obtained by inductively coupled plasma analysis are shown in Table 1 below.
[0106] Table 1
[0107]
[0108] Test Example 2
[0109] The catalysts obtained in the examples and comparative examples were subjected to formaldehyde removal experiments.
[0110] Take 0.1 g of the catalyst and place it in a tubular fixed-bed reactor for experiments respectively. The experimental conditions are as follows: the test gas contains 21 vol% oxygen, and the rest is nitrogen, and the formaldehyde concentration is 80 ppm; the humidity of the test gas is 50%.
[0111] The reaction space velocity (GHSV) is 30,000 - 100,000 mL / (g·h), and the reaction temperature is room temperature (25 °C). The test results are shown in Table 2 below.
[0112] Table 2
[0113] Reaction space velocity / mL / (g·h) Formaldehyde conversion rate / % Carbon dioxide selectivity / % Example 1 30000 100 100 Example 1 60000 100 100 Example 1 90000 100 100 Example 1 100000 98 100 Example 2 60000 90 100 Example 3 60000 100 100 Example 4 90000 85 98 Example 5 80000 78 95 Example 6 60000 83 90 Example 7 60000 50 80 Comparative Example 1 60000 10 60 Comparative Example 2 60000 25 80
[0114] As can be seen from Table 2, the catalysts with nano-AgMnO₂ with a spinel structure supported on molecular sieves in Examples 1 - 3 have high activity in the formaldehyde decomposition reaction; the catalysts with high-silica-alumina ratio molecular sieves as carriers in Examples 1, 4 - 5 have better activity; from Examples 1, 7 and Comparative Example 2, it can be seen that ozone treatment is very important for the formation of nano-AgMnO₂ with a spinel structure and the formaldehyde decomposition performance; from Comparative Example 1 and Comparative Example 2, it can be seen that the activity of highly dispersed nano-AgMnO₂ is higher than that of non-supported AgMnO₂ crystals. From Examples 1 and Comparative Example 2, it can be seen that even with the same loading method, the catalytic efficiency and selectivity of AgMnO₂ with different structures are different, and nano-AgMnO₂ with a spinel structure has better catalytic performance and carbon dioxide selectivity than ordinary nano-AgMnO₂.
[0115] Finally, it should be noted that the above-mentioned embodiments are only specific embodiments of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit it. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements for some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
Claims
1. A formaldehyde decomposition catalyst, characterized in that, The formaldehyde decomposition catalyst includes molecular sieve and nano-AgMnO2 supported on the molecular sieve; The nano-AgMnO2 has a pyrolusite structure.
2. The formaldehyde decomposition catalyst according to claim 1, characterized in that, The content of the nano-AgMnO2 is 1.0 - 10.0 wt%, preferably 5.0 - 8.0 wt%.
3. The formaldehyde decomposition catalyst according to claim 1, characterized in that, The silica-alumina ratio of the molecular sieve is 10 - 1000; Preferably, the molecular sieve includes zeolite molecular sieve; Preferably, the zeolite molecular sieve includes at least one of ZSM-5 molecular sieve, β molecular sieve and mordenite molecular sieve.
4. A method for preparing the formaldehyde decomposition catalyst according to any one of claims 1 to 3, characterized in that, The molecular sieve is impregnated in a solution containing a silver source and a manganese source, and after completion, it is dried, calcined and treated with ozone to obtain the formaldehyde decomposition catalyst.
5. The preparation method according to claim 4, characterized in that, In the solution containing a silver source and a manganese source, the silver source includes silver oxide; the manganese source includes manganese oxide; Preferably, in the solution containing a silver source and a manganese source, the concentration of the silver oxide is 1 - 10 wt%; the concentration of the manganese oxide is 1 - 10 wt%; Preferably, the impregnation time is 1 - 2 h; Preferably, the drying temperature is 80 - 120 °C; Preferably, the calcination temperature is 300 - 400 °C and the time is 4 - 6 h.
6. The preparation method according to claim 4, characterized in that, The process of the ozone treatment is as follows: Treatment is carried out with ozone at a concentration of 50-100 ppm at a temperature of 20-30 °C, and the volume space velocity is 500000-800000 h -1 , and the treatment time is 1-2 h.
7. A method for using the formaldehyde decomposition catalyst according to any one of claims 1 to 3, characterized in that, The formaldehyde decomposition catalyst is placed in a gas containing formaldehyde for reaction to remove formaldehyde.
8. The method of use according to claim 7, wherein, In the gas containing formaldehyde, the formaldehyde concentration ≤ 100 ppm and the space velocity ≤ 100 L / (g·h); Preferably, the humidity of the gas containing formaldehyde is 50 - 95%.
9. Use of the formaldehyde decomposition catalyst according to any one of claims 1 - 3 in removing formaldehyde at room temperature.
10. A room-temperature formaldehyde removal product, characterized in that, It includes the formaldehyde decomposition catalyst according to any one of claims 1 - 3.