Water-resistant integral VOCs catalytic oxidation catalyst as well as preparation method and application thereof

Abstract

The invention provides a water-resistant integral VOCs catalytic oxidation catalyst and a preparation method and application thereof.The catalyst comprises an integral VOCs catalytic oxidation catalyst body and a water-resistant protective layer, the integral VOCs catalytic oxidation catalyst body comprises a base material with open pore channels and VOCs catalytic oxidation catalyst bodies loaded on the inner surface and the outer surface of the base material, the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst comprises a metal oxide carrier with a porous structure and a noble metal active component loaded on the carrier, the waterproof protection layer comprises an inner hydrophobic layer, a middle hydrophilic layer and an outer hydrophobic layer from inside to outside, the inner hydrophobic layer and the outer hydrophobic layer are made of pure silicon molecular sieves and / or titanium silicon molecular sieves, and the middle hydrophilic layer is made of fumed silica. The catalyst provided by the invention has excellent catalytic oxidation activity on VOCs under the condition of high water content.

Description

Technical Field

[0001] The invention relates to a water-resistant integral VOCs catalytic oxidation catalyst and a preparation method and application thereof, belonging to the technical field of safety, environmental protection, energy conservation and water conservation. Background Art

[0002] VOCs is the abbreviation of volatile organic compounds, which can cause harm to human health and serious environmental pollution. For VOCs, the industrial application technologies used to treat them are mainly divided into the following: First, the biological method, that is, the exhaust gas containing VOCs is collected and passed through a biofilm filter bed, and water is sprayed on the biofilm filter bed to keep the surface of the biofilm moist. At the same time, the VOCs in the exhaust gas are washed down to contact, react, and degrade with the biofilm. VOCs are biologically decomposed into water and carbon dioxide, and the treated exhaust gas meets the emission standards. The advantage of this method is low treatment cost, and the disadvantage is that VOCs are not completely degraded. If it contains difficult-to-degrade VOCs, it is difficult for the exhaust gas to meet the emission standards. The second is the heat storage combustion method, that is, the exhaust gas containing VOCs is collected and sent to a combustion chamber equipped with heat storage materials, and then natural gas is sprayed into the combustion chamber as a combustion aid, so that the VOCs are burned and decomposed into water and carbon dioxide. The advantage of this method is that VOCs are completely decomposed, but the disadvantage is that the investment is large, the reaction temperature is as high as 700-800℃, the operating cost is high, and it is suitable for treating large-flow and high-concentration organic waste gas. The third is the catalytic combustion method, that is, the waste gas containing VOCs is collected and preheated to 400-500℃ and then sent into a combustion chamber equipped with a fixed bed catalyst. Under the action of the catalyst, VOCs are decomposed into carbon dioxide and water. The advantage of this method is that the reaction temperature is low and the operating cost is relatively low compared to the thermal storage combustion method. The disadvantage is that the investment is large, and if the catalyst is not selected appropriately, the VOCs will not be completely decomposed.

[0003] Researchers have conducted numerous studies on catalytic oxidation catalysts. For example, CN106732605A discloses a non-precious metal oxide catalyst with a water-resistant protective layer and a preparation method. The catalyst uses nano transition metal Fe / Co composite oxide as an active component and has a polymer porous film attached to the surface, which makes the catalyst have excellent water resistance. However, the catalyst is only suitable for the treatment of easily removable toxic gases such as CO and formaldehyde (required reaction temperature is low), while the temperature required for catalytic oxidation of VOCs including propane is generally high, and the polymer porous film on the catalyst surface will be thermally decomposed or coked at high temperatures.

[0004] CN108772075A discloses a catalyst for removing volatile benzene pollutants and a preparation method thereof, wherein the catalyst is composed of a noble metal active component and a carrier; wherein the noble metal active component is a single substance of platinum or platinum oxide; and the noble metal active component is 0.01%-0.05% of the total mass of the catalyst in terms of the noble metal element. The catalyst cannot isolate water from the catalyst, and under high temperature and high water content conditions, the agglomeration of the noble metal active component will be accelerated, thereby reducing the life of the catalyst.

[0005] CN113856748A discloses a hollow ZSM-5 catalyst with an atomic doping and metal cluster double modified inner surface and a preparation method, wherein the general formula of the catalyst is NOx@M-ZSM-5@Al-ZSM-5, wherein Al-ZSM-5 is a multi-level porous molecular sieve with an MFI structure, and M and N are transition metal elements. The catalyst is a double inner layer monolithic catalyst, wherein the outer Al-ZSM-5 and the middle layer M-ZSM-5 are tightly combined into a whole. Although the molecular sieve has good water resistance, the molecular sieve-based catalyst has the disadvantage of being easily coked and deactivated because its active center is in the molecular sieve pores or molecular sieve cages.

[0006] Therefore, providing a new type of water-resistant integral VOCs catalytic oxidation catalyst and its preparation method and application has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0007] In order to solve the above-mentioned shortcomings and deficiencies, an object of the present invention is to provide a water-resistant integral VOCs catalytic oxidation catalyst.

[0008] Another object of the present invention is to provide a method for preparing the above-mentioned water-resistant integral VOCs catalytic oxidation catalyst.

[0009] Another object of the present invention is to provide the use of the above-mentioned water-resistant integral VOCs catalytic oxidation catalyst in the catalytic oxidation of VOCs.

[0010] In order to achieve the above objectives, on the one hand, the present invention provides a water-resistant integral VOCs catalytic oxidation catalyst, wherein the water-resistant integral VOCs catalytic oxidation catalyst comprises an integral VOCs catalytic oxidation catalyst and a water-resistant protective layer, the integral VOCs catalytic oxidation catalyst comprises a substrate having open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst comprises a metal oxide carrier with a porous structure and a noble metal active component loaded on the carrier;

[0011] The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are made of pure silicon molecular sieve and / or titanium silicon molecular sieve, and the intermediate hydrophilic layer is made of fumed silica.

[0012] In the above-mentioned catalyst of the present invention, "inside" and "outside" are relative to the VOCs catalytic oxidation catalyst, the side close to the VOCs catalytic oxidation catalyst is the "inside", and the side away from the VOCs catalytic oxidation catalyst is the "outside".

[0013] In the above-mentioned catalyst of the present invention, the noble metal active component includes the oxide of the noble metal and the noble metal element. The VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, but the loading of the VOCs catalytic oxidation catalyst cannot block the open pores of the substrate, so that when the water-resistant integral VOCs catalytic oxidation catalyst is used to catalytically oxidize VOCs, VOCs can pass through the open pores smoothly. Among them, the inner surface is the surface of the open pores of the substrate, and the outer surface is such as the upper surface and the lower surface of the substrate.

[0014] As a specific embodiment of the catalyst described above in the present invention, the VOCs catalytic oxidation catalyst also includes an auxiliary metal oxide, which is loaded on the carrier. Based on the total weight of the carrier as 100%, the content of the auxiliary metal oxide is 0.5%-20%.

[0015] As a specific embodiment of the catalyst described above, the additive metal oxide comprises CeO 2 , MnO, CuO and La 2 O 3 In some preferred embodiments of the present invention, CeO 2 The content of MnO, CuO and La can be up to 20%. 2 O 3 The content can be up to 15%.

[0016] As a specific embodiment of the above-mentioned catalyst of the present invention, the noble metal includes one or a combination of Pt, Pd and Rh.

[0017] As a specific embodiment of the catalyst described above, based on the total weight of the carrier as 100%, the content of the noble metal active component in terms of noble metal is 0.5%-5%, that is, the mass ratio of the noble metal active component in terms of noble metal to the carrier is 0.5-5:100.

[0018] As a specific embodiment of the catalyst described above in the present invention, the porous metal oxide carrier comprises TiO 2 、SiO 2 、CeO 2 、ZrO 2 , Ce-Zr solid solution and γ-Al 2 O 3 One or a combination of the above.

[0019] As a specific embodiment of the catalyst described above in the present invention, the loading amount of the VOCs catalytic oxidation catalyst is 10%-20% based on the total weight of the substrate as 100%.

[0020] As a specific embodiment of the catalyst described above in the present invention, the content of the water-resistant protective layer is 1%-20% based on the total weight of the integral VOCs catalytic oxidation catalyst as 100%.

[0021] As a specific embodiment of the catalyst described above in the present invention, the pure silicon molecular sieve includes one or a combination of pure silicon MCM-41 molecular sieve, pure silicon β molecular sieve and Silicalite-1, and the titanium silicon molecular sieve includes TS-1 and / or TS-2.

[0022] In the above catalyst of the present invention, the materials of the inner hydrophobic layer and the outer hydrophobic layer may be the same or different.

[0023] As a specific embodiment of the catalyst described above in the present invention, the substrate includes two categories: ceramic carriers and metal carriers. The ceramic carrier includes cordierite honeycomb ceramics or silicon carbide honeycomb ceramics, and the metal carrier includes a metal honeycomb carrier, such as a metal honeycomb carrier made of iron-chromium-aluminum.

[0024] On the other hand, the present invention also provides a method for preparing the above-mentioned water-resistant integral VOCs catalytic oxidation catalyst, wherein the preparation method comprises:

[0025] Step (1): mixing an impregnation solution containing a noble metal precursor and a metal oxide support having a porous structure uniformly and then impregnating the mixture, and then drying and calcining the impregnated product to obtain a VOCs catalytic oxidation catalyst;

[0026] Step (2): mixing the VOCs catalytic oxidation catalyst, the binder, the peptizing agent, the dispersant and water and then ball-milling the mixture to form a catalyst slurry;

[0027] Step (3): immersing the substrate in the catalyst slurry, taking out the substrate, drying and calcining the substrate, and obtaining a monolithic VOCs catalytic oxidation catalyst;

[0028] Step (4): mixing pure silicon molecular sieve and / or titanium silicon molecular sieve, a dispersant and water and ball-milling to form a molecular sieve slurry, immersing the monolithic VOCs catalytic oxidation catalyst in the molecular sieve slurry, taking out the monolithic VOCs catalytic oxidation catalyst and drying and calcining it;

[0029] Step (5): mixing fumed silica, a dispersant and water and ball-milling the mixture to form a fumed silica slurry, immersing the product obtained after calcination in step (4) in the fumed silica slurry, taking out the product and drying and calcining it;

[0030] Step (6): Pure silicon molecular sieve and / or titanium silicon molecular sieve, dispersant and water are mixed and ball-milled to form a molecular sieve slurry, the product obtained after calcination in step (5) is immersed in the molecular sieve slurry, the product is taken out and then dried and calcined to obtain a water-resistant integral VOCs catalytic oxidation catalyst.

[0031] As a specific embodiment of the preparation method described above of the present invention, when the VOCs catalytic oxidation catalyst also includes an auxiliary metal oxide, in step (1), the impregnation solution containing the noble metal precursor and the auxiliary metal precursor and the metal oxide support with a porous structure are mixed evenly and then simultaneously impregnated, and the impregnation product is dried and calcined to obtain the VOCs catalytic oxidation catalyst;

[0032] Alternatively, an impregnation solution containing an auxiliary metal precursor and a metal oxide support with a porous structure are mixed evenly and then impregnated, dried and calcined, and then mixed evenly with an impregnation solution containing a noble metal precursor and then impregnated, dried and calcined to obtain a VOCs catalytic oxidation catalyst;

[0033] Alternatively, an impregnation solution containing a noble metal precursor and a porous metal oxide support are first mixed evenly and then impregnated. After drying and calcining, the impregnation solution containing an auxiliary metal precursor is then mixed evenly and then impregnated. After drying and calcining, a VOCs catalytic oxidation catalyst is obtained.

[0034] As a specific embodiment of the preparation method described above, the auxiliary metal precursor includes nitrate of auxiliary metal, etc. For example, when the auxiliary metal is cerium, manganese, copper, or lanthanum, the auxiliary metal precursor is cerium nitrate, manganese nitrate, copper nitrate, and lanthanum nitrate, respectively.

[0035] As a specific embodiment of the preparation method described above, the noble metal precursor includes nitrates of noble metals and the like.

[0036] As a specific embodiment of the preparation method described above, the dispersant includes polyvinyl alcohol and / or polyvinyl pyrrolidone, etc. The dispersant used in step (2), step (4) to step (5) of the preparation method of the present invention is used to stabilize the dispersed slurry and adjust the slurry viscosity, and the present invention does not make specific requirements on the amount of the dispersant, and its amount can be reasonably adjusted according to actual operation needs.

[0037] As a specific embodiment of the preparation method described above in the present invention, wherein the binder in step (2) includes pseudo-boehmite, etc., and the peptizing agent includes one or a combination of concentrated nitric acid, hydrochloric acid, acetic acid and citric acid, etc., preferably nitric acid. The present invention does not make specific requirements on the dosage of the binder and the peptizing agent, and their dosage can be reasonably adjusted according to actual operation needs.

[0038] As a specific embodiment of the preparation method described above in the present invention, in step (3), the substrate is immersed in the catalyst slurry, and the substrate is taken out and then dried and calcined. The above operation (i.e., immersion, drying and calcination) is repeated 2-4 times until the total weight of the substrate is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 10%-20%, thereby obtaining an integrated VOCs catalytic oxidation catalyst.

[0039] As a specific embodiment of the preparation method described above of the present invention, in step (1), step (3) to step (6), the calcination temperature is 400-750°C.

[0040] The present invention does not make specific requirements on the drying conditions, such as temperature and time, in the above-mentioned preparation method. The drying temperature and time can be reasonably adjusted according to actual operation needs, as long as the target substance can be dried.

[0041] As a specific embodiment of the preparation method described above in the present invention, in steps (3) to (5), the immersion time is 10-30 minutes.

[0042] On the other hand, the present invention also provides the use of the above-mentioned water-resistant integral VOCs catalytic oxidation catalyst in the catalytic oxidation of VOCs.

[0043] In some specific embodiments of the present invention, the VOCs may be, for example, VOCs contained in waste gas, and the waste gas has a relatively high water content, such as a water content not less than 10 wt %.

[0044] Compared with the prior art, the beneficial technical effects that can be achieved by the present invention include:

[0045] The present invention obtains a water-resistant integral VOCs catalytic oxidation catalyst by arranging a water-resistant protective layer on the surface of the integral VOCs catalytic oxidation catalyst, wherein the water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, the materials of the inner hydrophobic layer and the outer hydrophobic layer include pure silicon molecular sieve and / or titanium silicon molecular sieve, and the material of the intermediate hydrophilic layer includes fumed silica. Among them, the materials of the inner hydrophobic layer and the outer hydrophobic layer have super hydrophobic properties, which can separate the moisture in the exhaust gas from the integral VOCs catalytic oxidation catalyst inside the water-resistant integral VOCs catalytic oxidation catalyst to avoid contact between the two, thereby avoiding the problem of catalyst efficiency reduction or even deactivation due to the agglomeration of precious metal active components under high temperature and high water content conditions, thereby extending the life of the catalyst under water conditions; the material of the middle hydrophilic layer is hydrophilic gas-phase silica, and its main function is to guide part of the water vapor that passes through the outer hydrophobic layer horizontally (referring to the direction perpendicular to the open pore direction of the substrate) from this layer longitudinally (referring to the direction parallel to the open pore direction of the substrate), and reduce the agglomeration and deactivation of precious metal active components under high temperature and high water content conditions by combining water blocking and water diversion, that is, combining dredging and blocking.

[0046] In summary, compared with conventional integral VOCs catalytic oxidation catalysts, the presence of the water-resistant integral VOCs catalytic oxidation catalyst provided by the present invention solves the problem of decreased catalyst efficiency due to competitive adsorption between water molecules in the exhaust gas and VOCs (such as propane and other low-carbon alkanes) on the catalyst surface, thereby improving the catalytic oxidation activity of the catalyst for VOCs under high water content conditions. DETAILED DESCRIPTION

[0047] It should be noted that the term "comprises" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products or devices.

[0048] "Scope" disclosed in the present invention is given in the form of lower limit and upper limit. It can be one or more lower limits, and one or more upper limits respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower limit and upper limit define the boundaries of a particular range. All ranges defined in this way are combinable, i.e. any lower limit can be combined with any upper limit to form a range. For example, for a specific parameter, a range of 60-120 and 80-110 is listed, and it is understood that a range of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​listed are 1 and 2, and the maximum range values ​​listed are 3, 4 and 5, then the following ranges can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.

[0049] In the present invention, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in the present invention, and "0-5" is just an abbreviation of these numerical combinations.

[0050] In the present invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in the present invention can be combined with each other to form a new technical solution.

[0051] In the present invention, unless otherwise specified, all technical features and preferred features mentioned in the present invention can be combined with each other to form a new technical solution.

[0052] In the present invention, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0053] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the attached table and examples. The following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0054] Example 1

[0055] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0056] Step (1): Take CeO 2 20 g of cerium nitrate hexahydrate and 2 g of platinum nitrate as Pt were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0057] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0058] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.5 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting 3 times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 15% to obtain an integral VOCs catalytic oxidation catalyst.

[0059] Step (4): 20 g of Silicalite-1 molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 10 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 500° C. for 2 h.

[0060] Step (5): Take 20g of fumed silica, 2g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, immerse the catalyst obtained after calcination in step (4) in the second slurry, take it out after 10min, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, and then dry it at 110°C for 4h, then put it into a muffle furnace and calcine it at 400°C for 2h.

[0061] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 400°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0062] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pt active component (including Pt and its oxide) and CeO2 loaded on the carrier. 2 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are both made of Silicalite-1, and the intermediate hydrophilic layer is made of fumed silica;

[0063] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, i.e. CeO 2The content of Pt is 20%, the content of Pt active component is 2%, based on the total weight of the substrate is 100%, the loading amount of the VOCs catalytic oxidation catalyst is 15%, based on the total weight of the integral VOCs catalytic oxidation catalyst is 100%, and the content of the water-resistant protective layer is 5.4%.

[0064] Example 2

[0065] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0066] Step (1): Take CeO 2 20 g of cerium nitrate hexahydrate and 5 g of platinum nitrate as Pt were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0067] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0068] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting twice until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 10%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0069] Step (4): 50 g of Silicalite-1 molecular sieve, 6 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 10 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 400° C. for 2 h.

[0070] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 600°C for 2h.

[0071] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 500°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0072] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pt active component (including Pt and its oxide) and CeO2 loaded on the carrier. 2 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are both made of Silicalite-1, and the intermediate hydrophilic layer is made of fumed silica;

[0073] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, i.e. CeO 2 The content of Pt is 20%, the content of Pt active component is 5%, based on the total weight of the substrate is 100%, the loading amount of VOCs catalytic oxidation catalyst is 10%, based on the total weight of the integral VOCs catalytic oxidation catalyst is 100%, and the content of the water-resistant protective layer is 17%.

[0074] Example 3

[0075] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0076] Step (1): Dissolve 15 g of 50 wt% manganese nitrate solution in terms of MnO and 5 g of palladium nitrate in terms of Pd in ​​35 g of water. After the solution is completely dissolved, pour the resulting impregnation solution into 100 g of SiO2 After impregnation for 2 hours, the impregnated product was taken out and placed in a 120°C oven for drying for 4 hours. Then, it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0077] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0078] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting twice until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 10%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0079] Step (4): 60 g of Silicalite-1 molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 15 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 650° C. for 2 h.

[0080] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 600°C for 2h.

[0081] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 650°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0082] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pd active component (including Pd and its oxide) and MnO loaded on the carrier; the water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are both made of Silicalite-1, and the intermediate hydrophilic layer is made of fumed silica;

[0083] Among them, based on the total weight of the carrier as 100%, the content of the auxiliary metal oxide, i.e., MnO, is 15%, the content of the Pd active component as Pd is 5%, based on the total weight of the substrate as 100%, the loading amount of the VOCs catalytic oxidation catalyst is 10%, and based on the total weight of the integral VOCs catalytic oxidation catalyst as 100%, the content of the water-resistant protective layer is 20%.

[0084] Example 4

[0085] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0086] Step (1): Dissolve 15 g of copper nitrate (in terms of CuO) and 5 g of rhodium nitrate (in terms of Rh) in 50 g of water. After the solution is completely dissolved, pour the resulting impregnation solution into 100 g of CeO 2 After impregnation for 2 hours, the impregnated product was taken out and placed in a 120°C oven for drying for 4 hours. Then, it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0087] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0088] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.3 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting three times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 14.9%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0089] Step (4): 55 g of pure silicon β molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a pure silicon β molecular sieve slurry, recorded as the first slurry, and the obtained integral VOCs catalytic oxidation catalyst was immersed in the first slurry. After 15 min, it was taken out and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110°C for 4 h, and then placed in a muffle furnace and calcined at 750°C for 2 h.

[0090] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 750°C for 2h.

[0091] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 750°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0092] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and an Rh active component (including Rh and its oxide) and CuO loaded on the carrier; the water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the materials of the inner hydrophobic layer and the outer hydrophobic layer are both pure silicon β molecular sieve, and the material of the intermediate hydrophilic layer is fumed silica;

[0093] Among them, based on the total weight of the carrier as 100%, the content of the auxiliary metal oxide, i.e., CuO, is 15%, the content of the Rh active component as Rh is 5%, based on the total weight of the substrate as 100%, the loading amount of the VOCs catalytic oxidation catalyst is 14.9%, and based on the total weight of the integral VOCs catalytic oxidation catalyst as 100%, the content of the water-resistant protective layer is 18%.

[0094] Example 5

[0095] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0096] Step (1): Take La 2 O 3 15 g of lanthanum nitrate and 3 g of palladium nitrate were dissolved in 50 g of water. After the solution was completely dissolved, the obtained impregnation solution was poured into 100 g of TiO 2 After impregnation for 2 hours, the impregnated product was taken out and placed in a 120°C oven for drying for 4 hours. Then, it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0097] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0098] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.7 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting three times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 15.2%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0099] Step (4): 43 g of TS-1 molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a TS-1 molecular sieve slurry, recorded as the first slurry, and the obtained integral VOCs catalytic oxidation catalyst was immersed in the first slurry. After 15 min, it was taken out and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110°C for 4 h, and then placed in a muffle furnace and calcined at 550°C for 2 h.

[0100] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, immerse the catalyst obtained after calcination in step (4) in the second slurry, take it out after 10min, and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 550°C for 2h.

[0101] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 550°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0102] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pd active component (including Pd and its oxide) and La loaded on the carrier. 2 O 3The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are made of TS-1 molecular sieve, and the intermediate hydrophilic layer is made of fumed silica;

[0103] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, namely La 2 O 3 The content of Pd is 15%, the content of Pd active component is 3%, the total weight of the substrate is 100%, the loading amount of VOCs catalytic oxidation catalyst is 15.2%, and the total weight of the integral VOCs catalytic oxidation catalyst is 100%, and the content of the water-resistant protective layer is 15%.

[0104] Example 6

[0105] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0106] Step (1): Take La 2 O 3 15 g of lanthanum nitrate and 3 g of palladium nitrate were dissolved in 50 g of water. After the solution was completely dissolved, the obtained impregnation solution was poured into 100 g of ZrO 2 After impregnation for 2 hours, the impregnated product was taken out and placed in a 120°C oven for drying for 4 hours. Then, it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0107] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0108] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.9 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting three times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 15%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0109] Step (4): 45 g of TS-2 molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a TS-2 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 15 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110°C for 4 h, and then placed in a muffle furnace and calcined at 550°C for 2 h.

[0110] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, immerse the catalyst obtained after calcination in step (4) in the second slurry, take it out after 10min, and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 550°C for 2h.

[0111] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 550°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0112] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pd active component (including Pd and its oxide) and La loaded on the carrier. 2 O 3 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are made of TS-2 molecular sieve, and the intermediate hydrophilic layer is made of fumed silica;

[0113] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, namely La 2 O 3The content of Pd is 15%, the content of Pd active component is 3%, the total weight of the substrate is 100%, the loading amount of VOCs catalytic oxidation catalyst is 15%, and the total weight of the integral VOCs catalytic oxidation catalyst is 100%, and the content of the water-resistant protective layer is 15.3%.

[0114] Example 7

[0115] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0116] Step (1): Take CeO 2 10g of cerium nitrate hexahydrate and La 2 O 3 3 g of lanthanum nitrate, 1 g of platinum nitrate (Pt) and 1.5 g of palladium nitrate (Pd) were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of cerium-zirconium solid solution and stirred evenly for impregnation. After impregnation for 2 hours, the impregnated product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0117] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0118] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting 4 times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 20%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0119] Step (4): 35 g of Silicalite-1 molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 15 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 600° C. for 2 h.

[0120] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 500°C for 2h.

[0121] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 600°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0122] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pt active component (including Pt and its oxide) and a Pd active component (including Pd and its oxide) and CeO2 loaded on the carrier. 2 and La 2 O 3 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are made of Silicalite-1 molecular sieve, and the intermediate hydrophilic layer is made of fumed silica;

[0123] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, namely La 2 O 3 and CeO 2 The contents of Pd and Pt are 3% and 10% respectively, the contents of Pd active components in terms of Pd and Pt active components in terms of Pt are 1.5% and 1% respectively, based on the total weight of the substrate as 100%, the loading amount of the VOCs catalytic oxidation catalyst is 20%, and based on the total weight of the integral VOCs catalytic oxidation catalyst as 100%, the content of the water-resistant protective layer is 10.7%.

[0124] Example 8

[0125] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0126] Step (1): Take CeO 2 10g of cerium nitrate hexahydrate and La 2 O 3 3 g of lanthanum nitrate, 1 g of platinum nitrate, and 1.5 g of palladium nitrate were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0127] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0128] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.4 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting 4 times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 20%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0129] Step (4): 5 g of Silicalite-1 molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 15 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 600° C. for 2 h.

[0130] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 500°C for 2h.

[0131] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 600°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0132] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pt active component (including Pt and its oxide) and a Pd active component (including Pd and its oxide) and CeO2 loaded on the carrier. 2 and La 2 O 3 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are made of Silicalite-1 molecular sieve, and the intermediate hydrophilic layer is made of fumed silica;

[0133] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, namely La 2 O 3 and CeO 2 The contents of Pd and Pt are 3% and 10% respectively, the contents of Pd active components in terms of Pd and Pt active components in terms of Pt are 1.5% and 1% respectively, based on the total weight of the substrate as 100%, the loading amount of the VOCs catalytic oxidation catalyst is 20%, and based on the total weight of the integral VOCs catalytic oxidation catalyst as 100%, the content of the water-resistant protective layer is 1%.

[0134] Example 9

[0135] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0136] Step (1): Take CeO 220 g of cerium nitrate hexahydrate and 5 g of platinum nitrate as Pt were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0137] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0138] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting twice until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 10%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0139] Step (4): 50 g of Silicalite-1 molecular sieve, 6 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 10 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 400° C. for 2 h.

[0140] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 600°C for 2h.

[0141] Step (6): Take 50g of pure silicon β molecular sieve, 6g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30 minutes to obtain pure silicon β molecular sieve slurry, recorded as the third slurry, immerse the catalyst obtained after calcination in step (5) in the third slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 500°C for 2h to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0142] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pt active component (including Pt and its oxide) and CeO2 loaded on the carrier. 2 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the materials of the inner hydrophobic layer and the outer hydrophobic layer are Silicalite-1 and pure silicon β molecular sieve respectively, and the material of the intermediate hydrophilic layer is fumed silica;

[0143] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, i.e. CeO 2 The content of Pt is 20%, the content of Pt active component is 5%, based on the total weight of the substrate is 100%, the loading amount of VOCs catalytic oxidation catalyst is 10%, based on the total weight of the integral VOCs catalytic oxidation catalyst is 100%, and the content of the water-resistant protective layer is 17%.

[0144] Example 10

[0145] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0146] Step (1): Take CeO 2 20 g of cerium nitrate hexahydrate and 5 g of platinum nitrate as Pt were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0147] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0148] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting twice until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 10%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0149] Step (4): 50 g of TS-2 molecular sieve, 6 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a TS-2 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 10 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110°C for 4 h, and then placed in a muffle furnace and calcined at 400°C for 2 h.

[0150] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 600°C for 2h.

[0151] Step (6): 50 g of TS-1 molecular sieve, 6 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain TS-1 molecular sieve slurry, which was recorded as the third slurry. The catalyst obtained after calcination in step (5) was immersed in the third slurry, taken out after 30 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 500° C. for 2 h to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0152] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pt active component (including Pt and its oxide) and CeO2 loaded on the carrier. 2 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the materials of the inner hydrophobic layer and the outer hydrophobic layer are TS-2 and TS-1 respectively, and the material of the intermediate hydrophilic layer is fumed silica;

[0153] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, i.e. CeO 2 The content of Pt is 20%, the content of Pt active component is 5%, based on the total weight of the substrate is 100%, the loading amount of VOCs catalytic oxidation catalyst is 10%, based on the total weight of the integral VOCs catalytic oxidation catalyst is 100%, and the content of the water-resistant protective layer is 17%.

[0154] Embodiment 11

[0155] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0156] Step (1): Take CeO 2 20 g of cerium nitrate hexahydrate and 5 g of platinum nitrate as Pt were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0157] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0158] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting twice until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 10%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0159] Step (4): 50 g of TS-1 molecular sieve, 6 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a TS-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 10 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110°C for 4 h, and then placed in a muffle furnace and calcined at 400°C for 2 h.

[0160] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 600°C for 2h.

[0161] Step (6): 50g of pure silicon beta molecular sieve, 6g of polyvinyl alcohol and 300g of water were mixed and ball-milled for 30min to obtain pure silicon beta molecular sieve slurry, which was recorded as the third slurry. The catalyst obtained after calcination in step (5) was immersed in the third slurry, taken out after 30min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110°C for 4h, and then placed in a muffle furnace and calcined at 500°C for 2h to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0162] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pt active component (including Pt and its oxide) and CeO2 loaded on the carrier. 2The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the materials of the inner hydrophobic layer and the outer hydrophobic layer are TS-1 molecular sieve and pure silicon β molecular sieve respectively, and the material of the intermediate hydrophilic layer is fumed silica;

[0163] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, i.e. CeO 2 The content of Pt is 20%, the content of Pt active component is 5%, based on the total weight of the substrate is 100%, the loading amount of VOCs catalytic oxidation catalyst is 10%, based on the total weight of the integral VOCs catalytic oxidation catalyst is 100%, and the content of the water-resistant protective layer is 17%.

[0164] Example 12

[0165] This embodiment provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0166] Step (1): Take CeO 2 20 g of cerium nitrate hexahydrate and 0.5 g of platinum nitrate (Pt) were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0167] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0168] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting twice until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 10%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0169] Step (4): Take 50g TS-1 molecular sieve and pure silicon β molecular sieve, 6g polyvinyl alcohol and 300g water, mix them, and ball mill for 30min to obtain a mixed slurry of TS-1 pure silicon and β molecular sieve molecular sieve, recorded as the first slurry, and immerse the obtained integral VOCs catalytic oxidation catalyst in the first slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, and then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 400°C for 2h.

[0170] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 600°C for 2h.

[0171] Step (6): 50g of Silicalite-1 molecular sieve and TS-2 molecular sieve, 6g of polyvinyl alcohol and 300g of water are mixed and ball-milled for 30 minutes to obtain a mixed slurry of Silicalite-1 molecular sieve and TS-2 molecular sieve, which is recorded as the third slurry. The catalyst obtained after calcination in step (5) is immersed in the third slurry, taken out after 30 minutes, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic is purged with compressed air to avoid clogging the pores, and then dried at 110°C for 4 hours, and then placed in a muffle furnace and calcined at 500°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0172] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this embodiment includes a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst includes a cordierite honeycomb ceramic substrate with open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst includes a γ-alumina carrier and a Pt active component (including Pt and its oxide) and CeO2 loaded on the carrier. 2 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer is made of TS-1 molecular sieve and pure silicon β molecular sieve, the outer hydrophobic layer is made of Silicalite-1 molecular sieve and TS-2 molecular sieve, and the intermediate hydrophilic layer is made of fumed silica;

[0173] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, i.e. CeO 2 The content of Pt is 20%, the content of Pt active component is 0.5%, the total weight of the substrate is 100%, the loading amount of VOCs catalytic oxidation catalyst is 10%, and the total weight of the integral VOCs catalytic oxidation catalyst is 100%, and the content of the water-resistant protective layer is 17%.

[0174] Comparative Example 1

[0175] This comparative example provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0176] Step (1): Take CeO 2 10g of cerium nitrate hexahydrate and La 2 O 3 3 g of lanthanum nitrate, 1 g of platinum nitrate, and 1.5 g of palladium nitrate were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0177] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0178] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting 4 times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 20%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0179] Step (4): 35 g of Silicalite-1 molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 15 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 600° C. for 2 h.

[0180] Step (5): 20 g of Silicalite-1 molecular sieve, 3 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the second slurry. The catalyst obtained after calcination in step (4) was immersed in the second slurry, taken out after 10 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110°C for 4 h, and then placed in a muffle furnace and calcined at 500°C for 2 h.

[0181] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 600°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0182] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this comparative example comprises a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst comprises a cordierite honeycomb ceramic substrate having open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst comprises a γ-alumina carrier and a Pt active component (including Pt and its oxide) and a Pd active component (including Pd and its oxide) and CeO2 loaded on the carrier. 2 and La 2 O 3 The water-resistant protective layer includes an inner water-repellent layer, an intermediate water-repellent layer and an outer water-repellent layer from the inside to the outside, wherein the inner water-repellent layer, the intermediate water-repellent layer and the outer water-repellent layer are all made of Silicalite-1 molecular sieve;

[0183] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, namely La 2 O 3 and CeO 2The contents of Pd and Pt are 3% and 10% respectively, the contents of Pd active components in terms of Pd and Pt active components in terms of Pt are 1.5% and 1% respectively, based on the total weight of the substrate as 100%, the loading amount of the VOCs catalytic oxidation catalyst is 20%, and based on the total weight of the integral VOCs catalytic oxidation catalyst as 100%, the content of the water-resistant protective layer is 10.7%.

[0184] Comparative Example 2

[0185] This comparative example provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0186] Step (1): Take CeO 2 10g of cerium nitrate hexahydrate and La 2 O 3 3 g of lanthanum nitrate, 1 g of platinum nitrate, and 1.5 g of palladium nitrate were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0187] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0188] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting 4 times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 20%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0189] Step (4): 65 g of Silicalite-1 molecular sieve, 2 g of polyvinyl alcohol and 300 g of water were mixed and ball-milled for 30 min to obtain a Silicalite-1 molecular sieve slurry, recorded as the first slurry, and the obtained monolithic VOCs catalytic oxidation catalyst was immersed in the first slurry, taken out after 15 min, and the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic was purged with compressed air to avoid clogging the pores, and then dried at 110° C. for 4 h, and then placed in a muffle furnace and calcined at 600° C. for 2 h.

[0190] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 500°C for 2h.

[0191] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 600°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0192] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this comparative example comprises a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst comprises a cordierite honeycomb ceramic substrate having open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst comprises a γ-alumina carrier and a Pt active component (including Pt and its oxide) and a Pd active component (including Pd and its oxide) and CeO2 loaded on the carrier. 2 and La 2 O 3 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are made of Silicalite-1 molecular sieve, and the intermediate hydrophilic layer is made of fumed silica;

[0193] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, namely La 2 O 3 and CeO 2The contents of Pd and Pt are 3% and 10% respectively, the contents of Pd active components in terms of Pd and Pt active components in terms of Pt are 1.5% and 1% respectively, based on the total weight of the substrate as 100%, the loading amount of the VOCs catalytic oxidation catalyst is 20%, and based on the total weight of the integral VOCs catalytic oxidation catalyst as 100%, the content of the water-resistant protective layer is 22%.

[0194] Comparative Example 3

[0195] This comparative example provides a water-resistant integral VOCs catalytic oxidation catalyst, which is prepared by a preparation method comprising the following specific steps:

[0196] Step (1): Take CeO 2 10g of cerium nitrate hexahydrate and La 2 O 3 3 g of lanthanum nitrate, 1 g of platinum nitrate, and 1.5 g of palladium nitrate were dissolved in 50 g of water. After complete dissolution, the obtained impregnation solution was poured into 100 g of γ-alumina and stirred evenly for impregnation. After impregnation for 2 hours, the impregnation product was taken out and placed in a 120°C oven to dry for 4 hours. Then it was taken out and ground into powder, placed in a muffle furnace, and calcined at 550°C for 2 hours to obtain a powdered VOCs catalytic oxidation catalyst.

[0197] Step (2): 100 g of the obtained powdered VOCs catalytic oxidation catalyst, 10 g of pseudo-boehmite, 7.5 g of concentrated nitric acid, 250 g of water, and 1 g of polyvinyl alcohol are placed in a ball mill and 300 g of grinding balls are added. After ball milling for 2 hours, a catalyst slurry is obtained.

[0198] Step (3): Immerse the acid-treated cordierite honeycomb ceramic (mass 21.6 g) in the catalyst slurry, take it out after 10 minutes, and use compressed air to blow the remaining slurry in the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, then put it in a muffle furnace and roast it at 500°C for 4 hours, repeat the immersion, blowing, drying and roasting 4 times until the total weight of the cordierite honeycomb ceramic is 100% and the loading amount of the VOCs catalytic oxidation catalyst is 20%, thereby obtaining an integral VOCs catalytic oxidation catalyst.

[0199] Step (4): Take 35g of ordinary ZSM-5 molecular sieve with Si / Al (molar ratio) of 100, 2g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain ZSM-5 molecular sieve slurry, recorded as the first slurry, immerse the obtained integral VOCs catalytic oxidation catalyst in the first slurry, take it out after 15min, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, and then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 600°C for 2h.

[0200] Step (5): Take 20g of fumed silica, 3g of polyvinyl alcohol and 300g of water, mix them, and ball mill for 30min to obtain a fumed silica slurry, recorded as the second slurry, and immerse the catalyst obtained after calcination in step (4) in the second slurry. After 10min, take it out and use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4h, and then put it into a muffle furnace and calcine it at 500°C for 2h.

[0201] Step (6): immerse the catalyst obtained after calcination in step (5) in the first slurry, take it out after 30 minutes, use compressed air to blow the slurry remaining on the inner surface of the pores of the cordierite honeycomb ceramic to avoid clogging the pores, then dry it at 110°C for 4 hours, and then put it into a muffle furnace and calcine it at 600°C for 2 hours to obtain the water-resistant integral VOCs catalytic oxidation catalyst.

[0202] The water-resistant monolithic VOCs catalytic oxidation catalyst obtained in this comparative example comprises a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer, wherein the monolithic VOCs catalytic oxidation catalyst comprises a cordierite honeycomb ceramic substrate having open pores and a VOCs catalytic oxidation catalyst, wherein the VOCs catalytic oxidation catalyst is loaded on the inner surface and the outer surface of the substrate, and the water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst comprises a γ-alumina carrier and a Pt active component (including Pt and its oxide) and a Pd active component (including Pd and its oxide) and CeO2 loaded on the carrier. 2 and La 2 O 3 The water-resistant protective layer includes an inner hydrophobic layer, an intermediate hydrophilic layer and an outer hydrophobic layer from the inside to the outside, wherein the inner hydrophobic layer and the outer hydrophobic layer are made of ZSM-5 molecular sieve, and the intermediate hydrophilic layer is made of fumed silica;

[0203] Wherein, based on the total weight of the carrier as 100%, the additive metal oxide, namely La 2 O 3 and CeO 2The contents of Pd and Pt are 3% and 10% respectively, the contents of Pd active components in terms of Pd and Pt active components in terms of Pt are 1.5% and 1% respectively, the total weight of the substrate is 100%, the loading amount of the VOCs catalytic oxidation catalyst is 20%, and the total weight of the integral VOCs catalytic oxidation catalyst is 100%. Ordinary ZSM-5 molecular sieve is used instead of pure silicon molecular sieve, and the content of the water-resistant protective layer is 10.7%.

[0204] Catalyst Performance Evaluation Example 1

[0205] In this example, the catalytic activities of the monolithic VOCs catalytic oxidation catalysts provided in Examples 1 to 12 of the present invention (catalyst samples without a water-resistant protective layer in Examples 1 to 8 are respectively denoted as DC1 to DC8), the water-resistant monolithic VOCs catalytic oxidation catalysts (respectively denoted as C1 to C12), and the water-resistant monolithic VOCs catalytic oxidation catalysts provided in Comparative Examples 1 to 3 (respectively denoted as D1C7 to D3C7) are tested in a fixed bed catalytic reactor manufactured by Bo Luming (Beijing Technology) Co., Ltd., specifically including:

[0206] Three samples of the same catalyst (each with a size of 16×16×50 mm) were placed in a square reactor with a side length of 18 mm in the fixed bed catalytic reactor. Taking propane as the object, propane (product of Dalian Data Gas Co., Ltd.) was mixed with air and water vapor to form a propane content of 500 mg / m 3 , the water content of the mixed raw gas is 10wt%, and the mixed gas is heated for 16000h -1 The propane is oxidized by the catalyst at a fixed space velocity of 1.5 °C. The propane content in the mixed feed gas and the tail gas is detected by a 8860 gas chromatograph manufactured by Agilent Corporation of the United States. The propane removal rate at different temperatures is calculated. The temperature at which 98% of the propane is converted (T98) is used to measure the catalyst activity. The lower the T98, the higher the catalyst activity.

[0207] In this embodiment, T98 of DC1-DC8 and C1-C8 is shown in Table 1 below, T98 of C2, DC2 and C9-C12 is shown in Table 2 below, and T98 of C7, DC7 and D1C7-D3C7 is shown in Table 3 below.

[0208] Table 1

[0209] catalyst T98 / ℃ C1 280 DC1 336 C2 334 DC2 363 C3 357 DC3 366 C4 321 DC4 342 C5 328 DC5 342 C6 333 DC6 347 C7 254 DC7 297 C8 296 DC8 297

[0210] Table 2

[0211] catalyst T98 / ℃ C2 334 DC2 363 C9 348 C10 337 C11 350 C12 430

[0212] Table 3

[0213] catalyst T98 / ℃ C7 254 DC7 297 D1C7 280 D2C7 305 D3C7 342

[0214] It can be seen from Table 1 that compared with the integral VOCs catalytic oxidation catalyst samples provided in each embodiment without a water-resistant protective layer, the water-resistant integral VOCs catalytic oxidation catalyst provided in the corresponding embodiment has a lower T98, which indicates that in the embodiment of the present invention, providing a water-resistant protective layer on the integral VOCs catalytic oxidation catalyst can improve the catalytic activity of the catalyst to propane under high water content conditions.

[0215] As can be seen from Table 2, compared with C2 in Example 2, in which both the inner and outer hydrophobic layers are made of Silicalite-1 molecular sieve, the T98 of C2 and C11 in Examples 9 and 11, in which the outer hydrophobic layer is made of pure silicon β molecular sieve, is significantly increased, mainly because the pores of pure silicon β molecular sieve are relatively large and the performance of preventing water vapor from entering is relatively poor, while the T98 of C10 made in Example 10 is not much different from that in Example 2, because TS-1, TS-2 and Silicalite-1 molecular sieves are all MFI topological structures and have similar pore sizes. The T98 of C12 provided in Example 12 is higher, at 430°C, mainly because the content of precious metal active components in the catalyst is low.

[0216] As can be seen from Table 3, compared with D1C7 provided in Comparative Example 1 without an intermediate hydrophilic layer, the water-resistant activity of C7 provided in Example 7 is significantly improved, which indicates that the introduction of the intermediate hydrophilic layer helps to improve the water-resistant activity of the catalyst; compared with DC7 without a water-resistant protective layer, the water-resistant protective layer content in D2C7 exceeds 20%, and its T98 temperature rises instead, which indicates that the content of the water-resistant protective layer cannot be too high, otherwise it will hinder the contact between propane and the internal catalyst, resulting in a decrease in activity; Comparative Example 3 uses ordinary ZSM-5 molecular sieve to prepare D3C7, which not only fails to improve the water resistance of the catalyst, but because the ordinary ZSM-5 molecular sieve will adsorb more water vapor and contact with the catalyst, the catalyst activity is significantly reduced relative to DC-7 without a water-resistant protective layer.

[0217] The above is only a specific embodiment of the present invention, and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the protection scope of the patent of the present invention, should still fall within the scope of this patent. In addition, the technical features of the present invention can be freely combined with each other, with each other and with each other, and with each other.

Claims

1. A water-resistant monolithic VOCs catalytic oxidation catalyst, characterized in that, the water-resistant monolithic VOCs catalytic oxidation catalyst comprises a monolithic VOCs catalytic oxidation catalyst and a water-resistant protective layer. The monolithic VOCs catalytic oxidation catalyst comprises a substrate with open channels and a VOCs catalytic oxidation catalyst loaded on the inner and outer surfaces of the substrate. The water-resistant protective layer covers the VOCs catalytic oxidation catalyst; the VOCs catalytic oxidation catalyst comprises a porous metal oxide support and a noble metal active component loaded on the support; the water-resistant protective layer comprises an inner hydrophobic layer, a middle hydrophilic layer and an outer hydrophobic layer from the inside out. Among them, the materials of the inner hydrophobic layer and the outer hydrophobic layer include pure silica molecular sieve and / or titanium-silica molecular sieve, and the material of the middle hydrophilic layer includes fumed silica.

2. The catalyst according to claim 1, characterized in that, the VOCs catalytic oxidation catalyst further comprises a promoter metal oxide, which is loaded on the support. Based on the total weight of the support being 100%, the content of the promoter metal oxide is 0.5%-20%.

3. The catalyst according to claim 2, characterized in that, The promoter metal oxide includes CeO 2 , MnO, CuO and La 2 O 3 or a combination of one or more of them.

4. The catalyst according to claim 1, characterized in that, the noble metal includes one or a combination of several of Pt, Pd and Rh.

5. The catalyst according to claim 1 or 4, characterized in that, Based on the total weight of the support being 100%, the content of the noble metal active component in terms of noble metal is 0.5%-5%.

6. The catalyst according to any one of claims 1-4, characterized in that, The metal oxide support of the porous structure includes TiO 2 , SiO 2 , CeO 2 , ZrO 2 , a cerium-zirconium solid solution, and γ-Al 2 O 3 in one or a combination of several thereof.

7. The catalyst according to any one of claims 1-4, characterized in that, Based on the total weight of the substrate being 100%, the loading amount of the VOCs catalytic oxidation catalyst is 10%-20%.

8. The catalyst according to any one of claims 1-4, characterized in that, Based on the total weight of the monolithic VOCs catalytic oxidation catalyst being 100%, the content of the water-resistant protective layer is 1%-20%.

9. The catalyst according to any one of claims 1-4, characterized in that, the pure silica molecular sieve includes one or a combination of several of pure silica MCM-41 molecular sieve, pure silica β molecular sieve and Silicalite-1, and the titanium-silica molecular sieve includes TS-1 and / or TS-2.

10. The catalyst according to any one of claims 1-4, characterized in that, the substrate includes cordierite honeycomb ceramics, silicon carbide honeycomb ceramics or metal honeycomb carriers.

11. The preparation method of the water-resistant monolithic VOCs catalytic oxidation catalyst according to any one of claims 1-10, characterized in that, the preparation method comprises: Step (1): Mix an impregnating solution containing a noble metal precursor and a porous metal oxide support evenly, then carry out impregnation, and then dry and calcine the impregnated product to obtain a VOCs catalytic oxidation catalyst; Step (2): Mix the VOCs catalytic oxidation catalyst, a binder, a peptizing agent, a dispersant and water, and carry out ball milling to form a catalyst slurry; Step (3): Immerse the substrate in the catalyst slurry, take out the substrate and then dry and calcine it to obtain a monolithic VOCs catalytic oxidation catalyst; Step (4): Mix pure silica molecular sieve and / or titanium-silica molecular sieve, dispersant and water and ball-mill them to form a molecular sieve slurry. Immerse the monolithic VOCs catalytic oxidation catalyst in the molecular sieve slurry, take out the monolithic VOCs catalytic oxidation catalyst and then dry and calcine it; Step (5): Mix fumed silica, dispersant and water and ball-mill them to form a fumed silica slurry. Immerse the product obtained after calcination in step (4) in the fumed silica slurry, take out the product and then dry and calcine it; Step (6): Mix pure silica molecular sieve and / or titanium-silica molecular sieve, dispersant and water and ball-mill them to form a molecular sieve slurry. Immerse the product obtained after calcination in step (5) in the molecular sieve slurry, take out the product and then dry and calcine it to obtain a water-resistant monolithic VOCs catalytic oxidation catalyst.

12. According to the preparation method described in claim 11, wherein, when the VOCs catalytic oxidation catalyst further includes a promoter metal oxide, in step (1), mix the impregnation solution containing the noble metal precursor and the promoter metal precursor with the porous metal oxide support evenly and then carry out synchronous impregnation. After drying and calcining the impregnated product, obtain the VOCs catalytic oxidation catalyst; or first mix the impregnation solution containing the promoter metal precursor with the porous metal oxide support evenly and then carry out impregnation. After drying and calcining, mix it evenly with the impregnation solution containing the noble metal precursor and then carry out impregnation. After drying and calcining, obtain the VOCs catalytic oxidation catalyst; or first mix the impregnation solution containing the noble metal precursor with the porous metal oxide support evenly and then carry out impregnation. After drying and calcining, mix it evenly with the impregnation solution containing the promoter metal precursor and then carry out impregnation. After drying and calcining, obtain the VOCs catalytic oxidation catalyst; Preferably, the promoter metal precursor includes the nitrate of the promoter metal. More preferably, the noble metal precursor includes the nitrate of the noble metal.

13. According to the preparation method described in claim 11 or 12, wherein, the dispersant includes polyvinyl alcohol and / or polyvinylpyrrolidone.

14. According to the preparation method described in claim 11 or 12, wherein, in step (1) and steps (3)-(6), the calcination temperature is 400 - 750 °C.

15. Application of the water-resistant monolithic VOCs catalytic oxidation catalyst according to any one of claims 1-10 in catalytic oxidation of VOCs.