Catalytic material and cork board with formaldehyde decomposition function

A kind of catalytic material and cork board technical field with formaldehyde decomposition function

[0001] The present invention relates to the field of air purification technology.

Background technique

[0002] Formaldehyde is a type of carcinogen announced by the World Health Organization, and it is also the most important indoor pollutant that damages human health. Its main source is the cured urea-formaldehyde resin contained in artificial panels such as wall panels, ceilings, and furniture. At present, the main methods for removing indoor formaldehyde include green plant purification, porous material adsorption, chemical reaction, and catalytic oxidation technology. In comparison, the catalytic oxidation technology is the most effective method to control the hazards of formaldehyde. This method can convert the formaldehyde reaction into harmless carbon dioxide and water, with strong continuity and high efficiency. In the current existing catalytic oxidation technology, most of them use TiO2 as a catalyst to treat formaldehyde hazards, such as patents CN207617252U, CN20935101 1U, CN110452022A, but this material must work under ultraviolet conditions, and there is no ultraviolet light in the indoor environment. It needs to be coupled with other technical equipment for joint use.

[0003] In contrast, the supported metal catalyst can oxidize formaldehyde to carbon dioxide and water at room temperature without any external energy excitation, so that it has a good application prospect in indoor formaldehyde treatment. This type of catalyst usually needs to be molded and applied to an air purifier, and the operation of the purifier is used to increase the contact and reaction of formaldehyde gas with the catalyst. However, the purifier has a high operating cost and requires a certain amount of space indoors, which makes it difficult to popularize air purifiers. Therefore, it is necessary to further expand the application technology of the supported noble metal formaldehyde decomposition catalyst.

[0004] Cork board is a widely used green and environmentally friendly building material, in which cork storage cork board with excellent sound absorption and noise reduction, heat insulation, weather resistance and dimensional stability, etc. are often made into cork walls. Boards and other devices are used in large areas indoors, and the cork storage cork board has abundant pores on the surface, which has good adsorption capacity. If the supported noble metal formaldehyde decomposition catalyst is combined with the cork board, on the one hand, the catalyst can use the properties of the cork board to greatly increase its contact and reaction with formaldehyde in the air, and on the other hand, it can purify the air without adding new equipment. In the process of combining the catalyst with the cork board, how to make the catalyst particles firm and load as much as possible on the surface of the cork board is an important factor affecting the catalytic performance of the cork board. In the current research, most of the catalysts are mixed and stirred with film-forming substances and various additives to make coatings and then coated on the surface of the wood. Although high bonding strength catalysts/board materials can be obtained, a considerable part of the catalyst particles It is wrapped in other substances, thus losing the chance of contact with formaldehyde. In addition, conventional supported noble metal catalysts need to be reduced by H2 at high temperature (>300°C), which requires high operating requirements. This method is not suitable for such substrates as cork boards.

Summary of the invention

[0005] In view of the above problems, one of the objectives of the present invention is to provide a catalyst with a bonding layer, including a bonding layer and a catalytic layer on the surface of the bonding layer, the catalytic layer comprising TiO2 and active metal components, The mass ratio of the active metal component to TiO2 is 0.05%-5%;

[0006] The bonding layer includes an oligomeric resin, a photoinitiator, and a reactive monomer diluent.

[0007] Preferably, the crystal form of the TiO2 particles is one or a mixture of two or more of anatase and rutile.

[0008] Preferably, the active metal component is one or a mixture of two or more of Pt, Pd, and Ag.

[0009] The oligomeric resin is epoxy acrylate (EA), polyurethane acrylate (PUA), polyester acrylate (PE),

One or a mixture of two or more of polyether acrylate (PO).

[0010] The reactive monomer diluent is isodecyl acrylate (ISODA), lauryl acrylate (LA), tripropylene glycol diacrylate (TPGDA), trimethylol (DTMPTTA), dipentaerythritol (DPHA) ) One or a mixture of two or more.

[0011] The second object of the present invention is to provide a cork board with the function of catalytic decomposition of formaldehyde at room temperature, including a cork board carrier, an adhesive layer on the surface of the cork board carrier, and the surface of the adhesive layer includes TiO2 and an active metal group. The mass ratio of the adhesive layer to the cork board is 2%-10%, the mass ratio of the TiO2 to the cork board carrier is 0.4%-20%, and the active metal component and the TiO2 The mass ratio is 0.05%-5%.

[0012] As an embodiment of the present invention, the cork board is Castanopsis cortex cork board.

[0013] Preferably, the porosity of the cork board carrier is 2%-10%, and the density is 120-240kg/m³。

[0014] Preferably, the adhesive layer includes an oligomeric resin, a photoinitiator, and a reactive monomer diluent.

[0015] The oligomeric resin is one or a mixture of two or more of epoxy acrylate (EA), polyurethane acrylate (PUA), polyester acrylate (PE), and polyether acrylate (PO).

[0016] The reactive monomer diluent is isodecyl acrylate (ISODA), lauryl acrylate (LA), tripropylene glycol diacrylate (TPGDA), trimethylol (DTMPTTA), dipentaerythritol (DPHA) ) One or a mixture of two or more.

[0017] The crystal form of the TiO2 particles is one or two of anatase and rutile; preferably, the particle size of the TiO2 particles is 10-100 nm.

[0018] The active metal component is one or a mixture of two or more of Pt, Pd, and Ag.

[0019] The second object of the present invention is to provide a method for preparing a cork board with the function of catalytic decomposition of formaldehyde at room temperature as described above, including the following steps:

[0020] (1) 40-70 parts by mass of oligomeric resin, 3-5 parts by mass of photoinitiator, 20-50 parts by mass of reactive monomer diluent, 0.1-1 parts by mass of defoamer, 1-2 parts by mass Dispersant, 0.2-0.5 parts by mass of leveling agent, and 3-5 parts by mass of matting powder are mixed and stirred evenly, and the cork board is immersed in it for 5-30min, and dried at 30-60°C in the dark for 0.5-2h to obtain a cork board carrier .

[0021] (2) Disperse the TiO2 powder in the active metal component precursor solution, stir evenly, and put the cork board carrier prepared in step (1) into the TiO2/active metal component precursor solution and soak for 5-30 min , Keep away from light and dry for 6-12h at 30-60°C.

[0022] Using a high-pressure mercury lamp with a wavelength of 320-370nm as a radiation source for curing and reduction for 1-4h.

[0023] The precursor of the active component is one or a mixture of two or more of nitrate, chloride, and acetate.

[0024] The present invention uses a light-curable resin as an adhesive, and uses a dipping method to load the active metal components on the surface of the adhesive layer. The cork board can continuously and efficiently decompose indoor formaldehyde at room temperature to provide a safe indoor environment; At the same time, after ultraviolet light irradiation treatment, the catalyst fixation and active component reduction can be completed in one step; thus, the adhesion between the titanium oxide and the active metal component, the bonding layer and the cork board carrier is improved, and it is not easy to fall off during use At the same time, the preparation method of the cork board provided by the present invention is simple and has high production efficiency.

Detailed ways

[0025] In order to make the objectives and technical solutions of the embodiments of the present invention clearer, the technical solutions of the present invention will be described clearly and completely in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

Example 1

[0027] 60 parts of epoxy acrylate (EA), 30 parts of isodecyl acrylate (QSODA), 3 parts of photoinitiator, 0.5 parts of defoamer, 1 part of dispersant, 0.5 part of leveling agent, 5 parts of matting agent Mix and stir to obtain a solution; the density is 180kg/m³, The cork board with a porosity of 4.2% is immersed in the above solution for 20 minutes, and the amount of immersion is 5wt% relative to the mass of the cork board, and dried at 30 °C for 2h to obtain a cork board support; the anatase TiO2 with a particle size of 10nm The powder is dispersed in a 0.05mol/L cloperic acid solution, in which the Pt loading is 1% in terms of TiO2. After stirring, the cork board carrier obtained above is put into the solution and immersed for 10 minutes, and the dipping amount is calculated as the cork board carrier It is 2%, dried for 6h at 30°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 370nm for 1h to obtain the final catalyzed cork board. The performance evaluation of the catalytic cork board is carried out in a self-made formaldehyde static evaluation device, which is composed of a bubbling device, a quartz glass box, a fan, a formaldehyde detector, and a glass dish. The volume of the quartz glass box is about 27L, a petri dish is placed at the bottom for the catalytic cork board, and the upper part has a sealing cover that can freely adjust the height. The petri dish can be sealed when the formaldehyde concentration is stable to avoid the adsorption of formaldehyde by the quartz glass. , Paste a layer of foil inside the quartz glass. The bubbling device can quantitatively blow out formaldehyde gas into the quartz glass chamber; the fan inside the quartz glass box can promote the air flow in the chamber; the formaldehyde detector model is American Interscan 4160, which can quickly and accurately measure the concentration of formaldehyde in the pipeline. The specific test steps are: first put a 10cm*10cm*2cm square in a glass dish. Shaped cork board and sealed with a sealing cap. Then use a formaldehyde bubbling device to blow formaldehyde gas into the quartz glass chamber, use a circulating water pump to control the temperature of the formaldehyde solution to 4°C, and use high-purity oxygen for bubbling with a gas velocity of 10 ml/min. At this time, a formaldehyde detector is used to read the gas concentration in the circulating pipeline in real time. When the concentration reaches about 10 Ppm (denoted as C0), stop the gas blowing, lift the sealing cover, and let the catalytic cork board contact and react with the formaldehyde gas. Display the number, and record the concentration of formaldehyde in the pipeline in real time (denoted as C). The real-time formaldehyde conversion rate of the catalyzed cork board = (C0-C) /C0*%.

[0028] Through detection, the catalytic cork board prepared in this embodiment has a formaldehyde conversion rate of 12.25% when the reaction is 2h, the formaldehyde conversion rate is 22.53% when the reaction is 5h, and 98.54% when the reaction is 24h, almost complete conversion .

[0029] The catalytic cork board after one month of use will be tested for the retention of TiO2 and active metal components. The test method is to calcinate the prepared catalytic cork board in an oxygen atmosphere, and the calcining temperature is 1000° C., weighing and calcining The mass of the obtained mixture is m1; according to the same method, the catalyzed cork board that has been used for one month is calcined in an oxygen atmosphere at 1000 c, and the mass of the calcined mixture is weighed as m2, because the same batch of cork boards can be It is believed that the mass ratio of titanium oxide to active metal components is the same, and thus the retention rate = m2/m1*100%; the test confirmed that after one month of use, the retention rate of TiO2 and active metal components reached 99.8%.

Example 2

[0031] 40 parts of polyurethane acrylate (PUA), 50 parts of lauryl acrylate (LA), 5 parts of photoinitiator, 0.1 part of defoamer, 1.7 parts of dispersant, 0.2 part of leveling agent, and 3 parts of matting agent are mixed Stir evenly to obtain the solution; set the density to 120kg/m³, The cork board with a porosity of 6.1% is immersed in the above solution for 25 minutes, and the dipping amount is 8wt% relative to the mass of the cork board, and dried at 60°C for 0.5h. Disperse the anatase TiO2 powder with a particle size of 10nm in a 0.05mol/L palladium acetate solution, where the Pd loading is 5% as TiO2. After stirring uniformly, put the cork board carrier obtained above into the solution Immerse for 5 minutes, the amount of impregnation is 0.4% of the cork board carrier, and it is dried for 12 hours at 30°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 340nm for 2 hours to obtain the final catalytic cork board.

[0032] Through testing, the catalytic cork board prepared in this example has a formaldehyde conversion rate of 17.70% when the reaction is 5h, and can reach 61.08% when the reaction is 24h, and the reaction time lasts to 48h when almost completely converted; after one month of use, TiO2 And the retention rate of active metals reaches 99.5%.

Example 3

[0034] 70 parts of polyester acrylate (PE), 20 parts of tripropylene glycol diacrylate (TPGDA), 3.2 parts of photoinitiator, 1 part of defoamer, 2 parts of dispersant, 0.3 parts of leveling agent, 3.5 parts Mix and stir parts of the matting agent evenly. Set the density to 165kg/m³, A cork board with a porosity of 10% is immersed in the above solution for 30 minutes, and the amount of immersion is 10wt% relative to the mass of the cork board, and dried at 50°C for 1 hour to obtain a cork board support; the rutile TiO2 powder with a particle size of 55nm is dispersed In a 0.05mol/L palladium acetate solution, the Pd loading amount is 0.05% in terms of TiO2. After stirring, put the cork board carrier obtained above into the solution and soak for 30 minutes, and the impregnation amount is 20% for the cork board carrier. After drying for 10 hours at 60°C in the dark, and finally curing and reducing with a high-pressure mercury lamp with a wavelength of 365nm for 2 hours to obtain the final catalytic cork board.

[0035] Through detection, the formaldehyde conversion rate of the catalyzed cork board prepared in this example was 8.74% when the reaction was 5h, 41.96% when the reaction was 24h, and 84.93% when the reaction time lasted to 48h; after one month of use , The retention rate of TiO2 and active metals reached 99.4%.

Example 4

[0037] 55 parts of polyether acrylate (PO), 35 parts of trimethylol (DTMPTTA), 3.5 parts of photoinitiator, 0.6 parts of defoaming agent, 2 parts of dispersant, 0.3 parts of leveling agent, 3.6 parts Mix and stir parts of the matting agent to obtain a solution; the density is 240kg/m³The cork board with a porosity of 2% was immersed in the above solution for 5 minutes, and the dipping amount was 2wt% relative to the mass of the cork board, and dried at 30°C for 2 hours. Disperse the rutile TiO2 powder with a particle size of 55nm in a 0.1mol/L silver nitrate solution, where the Ag loading is 2% as TiO2. After stirring, put the cork board carrier obtained above into the solution and soak for 10 minutes The impregnation amount is 5% of the cork board carrier, and it is dried for 6h at 50°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 365nm for 4h to obtain the final catalyzed cork board.

[0038] Through detection, the catalytic cork board prepared in this example has a formaldehyde conversion rate of 46.23% during the reaction for 2h, and complete conversion of formaldehyde during the reaction for 5h; after one month of use, the retention rate of TiO2 and active metals reached 98.8%.

Example 5

[0040] Mix 55 parts of polyether acrylate (PO), 35 parts of dipentaerythritol (DPHA), 3.5 parts of photoinitiator, 0.6 parts of defoamer, 2 parts of dispersant, 0.3 parts of leveling agent, and 3.6 parts of matting agent Stir evenly to obtain the solution; set the density to 186kg/m³, The cork board with a porosity of 5.2% was immersed in the above solution for 20 minutes, and the dipping amount was 5wt% relative to the mass of the cork board, and dried at 50°C for 1 hour. Disperse anatase TiO2 powder with a particle size of 10nm in a 0.05mol/L palladium acetate solution, where the Pd loading is 1% based on TiO2. After stirring uniformly, put the above obtained cork board carrier into the solution Immersion for 10min, the impregnation amount is 2% of the cork board carrier, and it is dried for 6h at 30°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 365nm for 2h to obtain the final catalytic cork board.

[0041] Through testing, the catalytic cork board prepared in this example has a formaldehyde conversion rate of 26.14% in 2h reaction, 54.39% in reaction 5h, and can be completely converted in 12h; after one month of use, TiO2 and activity The metal retention rate reached 98.4%.

Example 6

[0043] 70 parts of polyether acrylate (PO), 20 parts of trimethylol (DTMPTTA), 3.2 parts of photoinitiator, 1 part of defoaming agent, 2 parts of dispersant, 0.3 parts of leveling agent, 3.5 parts Mix and stir parts of the matting agent to obtain a solution. Set the density to 190kg/m³The cork board with a porosity of 4.5% was immersed in the above solution for 20 minutes, and the dipping amount was 5wt% relative to the mass of the cork board, and dried at 50°C for 1 hour. Disperse the rutile TiO2 powder with a particle size of 55nm in a 0.1mol/L chloroplatinic acid solution, where the Pt loading amount is 0.5% as TiO2. After stirring, put the cork board support obtained above into the solution and soak 15min, the immersion amount was 5% of the cork board carrier, and dried for 6h at 50°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 325nm for 2h to obtain the final catalyzed cork board.

[0044] Through testing, the catalytic cork board prepared in this example has a formaldehyde conversion rate of 27.48% when the reaction is 5h, and the formaldehyde conversion rate is 62.01% when the reaction is 12h, and can be completely converted at 24h; after one month of use, TiO2 and activity The retention rate of metals reached 99.7%.

Example 7

[0046] 40 parts of polyester acrylate (PE), 50 parts of lauryl acrylate (LA), 5 parts of photoinitiator, 0.1 part of defoamer, 1.7 parts of dispersant, 0.2 part of leveling agent, 3 parts of matting agent Mix and stir to obtain a solution. Set the density to 145kg/m³The cork board with a porosity of 4.6% was immersed in the above solution for 20 minutes, and the dipping amount was 5wt% relative to the mass of the cork board, and dried at 30 °C for 2 hours. Disperse the rutile TiO2 powder with a particle size of 55nm in a 0.05mol/L chloroplatinic acid solution, where the Pt loading amount is 5% as TiO2, and after stirring uniformly, put the above-obtained cork board carrier into the solution to soak 10min, the impregnation amount is 2% of the cork board carrier, and it is dried for 12h at 30°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 370nm for 4h to obtain the final catalyzed cork board.

[0047] Through detection, the catalytic cork board prepared in this example has a formaldehyde conversion rate of 33.92% when the reaction is 2h, and the formaldehyde conversion rate is 78.70% when the reaction is 5h, and the formaldehyde is completely converted when the reaction is 12h; after one month of use, TiO2 and The retention rate of active metals reached 99.4%.

Embodiment 8

[0049] 60 parts of polyester acrylate (PE), 30 parts of trimethylol (DTMPTTA), 3 parts of photoinitiator, 0.5 parts of defoaming agent, 1 part of dispersant, 0.5 parts of leveling agent, 5 parts Parts of the matting agent are mixed and stirred to obtain a solution; the density is 180kg/m³, The cork board with a porosity of 8.5% is immersed in the above solution for 20 minutes, and the dipping amount is 5wt% relative to the mass of the cork board, and dried at 60°C for 0.5h. Disperse the rutile TiO2 powder with a particle size of 55nm in a 0.1mol/L chloroplatinic acid solution, where the Pt loading is 2% as TiO2. After stirring, put the cork board carrier obtained above into the solution and soak 15min, the immersion amount is 5% of the cork board carrier, and it is dried for 10h at 60°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 325nm for 3h to obtain the final catalyzed cork board.

[0050] Through testing, the catalytic cork board prepared in this embodiment has a formaldehyde conversion rate of 45.06% when the reaction is 2h, and the formaldehyde is completely converted when the reaction is 5h; after one month of use, the retention rate of TiO2 and active metals reached 99.1%.

Example 9

[0052] 40 parts of polyurethane acrylate (PUA), 50 parts of lauryl acrylate (LA), 5 parts of photoinitiator, 0.1 part of defoamer, 1.7 parts of dispersant, 0.2 part of leveling agent, and 3 parts of matting agent are mixed Stir evenly to obtain the solution; set the density to 200kg/m³, The cork board with a porosity of 9.8% is immersed in the above solution for 30 minutes, and the dipping amount is 10wt% relative to the mass of the cork board, and dried at 30°C for 1 hour. Disperse anatase TiO2 powder with a particle size of 50nm in a 0.05mol/L palladium acetate solution, where the Pd loading is 1% based on TiO2, and after stirring uniformly, put the above-obtained cork board carrier into the solution Immerse for 10min, the amount of impregnation is 2% of the cork board carrier, and dry it at 30°C in the dark for 10h. Finally, it is cured and reduced by a high-pressure mercury lamp with a wavelength of 320nm for 4h to obtain the final catalytic cork board.

[0053] Through detection, the formaldehyde conversion rate of the catalyzed cork board prepared in this example was 28.81% when the reaction was 5h, and the formaldehyde conversion was 55.75% when the reaction was 12h, and the formaldehyde can be completely converted at 24h; after one month of use, The retention rate of TiO2 and active metals reached 99.3%.

Embodiment 10

[0055] 60 parts of polyester acrylate (PE), 30 parts of trimethylol (DTMPTTA), 3 parts of photoinitiator, 0.5 parts of defoaming agent, 1 part of dispersant, 0.5 parts of leveling agent, 5 parts Mix and stir parts of the matting agent evenly. Set the density to 165kg/m³The cork board with a porosity of 5.8% is immersed in the above solution for 25 minutes, and the dipping amount is 8wt% relative to the mass of the cork board, and dried at 30°C

Dry for 1h. Disperse the rutile TiO2 powder with a particle size of 55nm in a 0.05mol/L chloroplatinic acid solution, where the Pt loading is 5% as TiO2. After stirring, put the cork board carrier obtained above into the solution and soak For 10min, the immersion amount is 2% of the cork board carrier, and it is dried for 10h at 60°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 365nm for 4h to obtain the final catalyzed cork board.

[0056] Through detection, the catalytic cork board prepared in this example has a formaldehyde conversion rate of 41.68% when the reaction is 2h, and the formaldehyde conversion rate is 94.52% when the reaction is 5h, and formaldehyde is almost completely converted; after one month of use, TiO2 and active metals The retention rate reached 99.3%.

[0057] Comparative sample 1

[0058] 60 parts of polyester acrylate (PE), 30 parts of styrene, 3 parts of photoinitiator, 0.5 parts of defoaming agent, 1 part of dispersant, 0.5 parts of leveling agent, and 5 parts of matting agent are mixed and stirred uniformly to obtain Solution; change the density to 180kg/m³The cork board with a porosity of 8.5% was immersed in the above solution for 20 minutes, and the dipping amount was 5wt% relative to the mass of the cork board, and dried at 60°C for 0.5h. Disperse the rutile TiO2 powder with a particle size of 55nm in a 0.1mol/L chloroplatinic acid solution, where the Pt loading is 2% as TiO2. After stirring, put the cork board obtained above into the solution and soak for 15min The impregnation amount is 5% of the cork board carrier, and it is dried for 10h at 60°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 325nm for 3h to obtain the final catalyzed cork board.

[0059] In this example, styrene is used as the diluent. When preparing the catalyzed cork board, it is found that the adhesive layer has a slow curing speed and weak bonding force with the cork board. Through testing, the formaldehyde conversion rate of the catalyzed cork board was only 12.52% at 24h; after one month of use, the retention rate of TiO2 and active metals reached 88.2%.

[0060] Comparative sample 2

[0061] 70 parts of polyether acrylate (PO), 20 parts of trimethylol (DTMPTTA), 3.2 parts of photoinitiator, 1 part of defoaming agent, 2 parts of dispersant, 0.3 parts of leveling agent, 3.5 parts Parts of the matting agent are mixed and stirred to obtain a solution; the density is 190kg/m³The cork board with a porosity of 4.5% was immersed in the above solution for 20 minutes, and the dipping amount was 5wt% relative to the mass of the cork board, and dried at 50°C for 1 hour. Disperse the rutile TiO2 powder with a particle size of 55nm in a 0.1mol/L copper nitrate solution, where the Cu loading is 0.5% as TiO2. After stirring uniformly, put the cork board carrier obtained above into the solution and soak for 15min The impregnation amount is 5% of the cork board carrier, and it is dried for 6h at 50°C in the dark, and finally cured and reduced by a high-pressure mercury lamp with a wavelength of 365nm for 2h to obtain the final catalyzed cork board.

[0062] Through testing, the catalytic cork board prepared in this example has almost no catalytic performance for formaldehyde.

[0063] Comparative sample 3

[0064] Mix 40 parts of polyurethane acrylate (PUA), 50 parts of lauryl acrylate (LA), 5 parts of photoinitiator, 0.1 part of defoamer, 1.7 parts of dispersant, 0.2 part of leveling agent, and 3 parts of matting agent Stir evenly to obtain a solution. Set the density to 200kg/m³, The cork board with a porosity of 9.8% is immersed in the above solution for 30 minutes, and the dipping amount is 10wt% relative to the mass of the cork board, and dried at 30°C for 1 hour. Disperse anatase TiO2 powder with a particle size of 50nm in a 0.05mol/L palladium acetate solution, where the Pd loading is 1% based on TiO2, and after stirring uniformly, put the above-obtained cork board carrier into the solution Immerse for 10min, the amount of immersion is 2% of the cork board carrier, dry for 10h at 30°C in the dark, and finally use a low-pressure mercury lamp with a wavelength of 253nm to cure and reduce for 4h to obtain the final catalyzed cork board.

[0065] The wavelength of the mercury lamp used in this example is 253nm, and after testing, it is found that the formaldehyde conversion rate at 24h is only 14.52%.

[0066] Comparative Example 4

[0067] The anatase TiO2 powder with a particle size of 10 nm was dispersed in a 0.05 mol/L palladium acetate solution, where the Pd negative

The loading is 5% based on TiO2. After stirring evenly, put the cork board in the above solution and soak for 5min, the dipping amount is 0.4% of the cork board, and dry it at 30°C in the dark for 12h, and then dry to obtain the final catalytic cork board. .

[0068] Through detection, the catalytic cork board prepared in this example has a formaldehyde conversion rate of 17.62% when the reaction is 5h, and can reach 50.25% when the reaction is 24h; after one month of use, the retention rate of TiO2 and active metals reaches 41.8%; Compared with Example 2, due to the lack of a binder layer, the retention rate of TiO2 and active metals is lower.

[0069] Comparative Example 5

[0070] Set the density to 120kg/m³, The cork board with a porosity of 6.1% is immersed in a PTFE solution for 25 minutes, and the amount of immersion is 8wt% relative to the mass of the cork board carrier, and the cork board carrier is obtained by drying at 60°C for 0.5h; the anatase with a particle size of 10nm The mineral TiO2 powder is dispersed in a 0.05mol/L palladium acetate solution, where the Pd loading is 5% as TiO2. After stirring, the cork board carrier obtained above is put into the solution and immersed in the solution for 5 minutes, and the amount of impregnation is cork board 0.4% of the carrier, dried for 12 hours at 30°C in the dark, and dried to obtain the final catalytic cork board.

[0071] Through detection, the formaldehyde conversion rate of the catalytic cork board prepared in this example is 15.36% when the reaction is 5h, 54.32% when the reaction is 24h, and the formaldehyde conversion rate can reach 82.87% when the reaction time lasts to 48h; use one Months later, the retention rate of TiO2 and active metals reached 52.8%; compared with Example 2 and Comparative Example 4, using PTFE as the binder layer has limited adhesion to TiO2.

[0072] Comparative sample 6

[0073] Compared with the catalytic oxidation method, the adsorption method is currently the most widely used method for removing formaldehyde. Commercially available activated carbon (JEC) was used for the experiment, and the specific surface area of the activated carbon was 1056 cm.^-1/g, first pretreat the activated carbon, soak in deionized water for 4h to remove surface impurities, then dry it at 120°C for 12h, grind and screen, and control the particle size between 250um-350um. Take 0.05g of the above activated carbon and place it in the reactor to test its formaldehyde removal performance.

[0074] Through detection, the formaldehyde removal rate can reach 48.36% at 5h, but the formaldehyde removal rate drops to 46.75% by 12h, and the removal rate has not increased as time increases. This may be because the removal of formaldehyde by activated carbon is a physical function. When the adsorption is saturated, it will stop adsorbing formaldehyde, and even release formaldehyde into the room, and the end of adsorption is difficult to judge.