A dual-layer integrated synergistic NO removal x Catalysts for VOCs, their preparation methods and applications

Abstract

This invention provides a dual-layer integral synergistic NO removal method x This application relates to catalysts for the synergistic removal of NOx and VOCs, their preparation methods, and applications. The bilayer monolithic catalyst for the synergistic removal of NOx and VOCs comprises: a support, and an inner catalyst layer and an outer catalyst layer stacked on the surface of the support; the inner catalyst layer comprises an oxide of a first non-noble metal and a noble metal, wherein the first non-noble metal includes one or more of Mn, V, Ti, Co, and Ce, and the noble metal includes one or more of Pt, Pd, and Rh; the outer catalyst layer comprises an oxide of Cu and an oxide of a second non-noble metal, wherein the second non-noble metal includes one or more of Mn, V, Ti, Co, and Ce. The catalyst provided in this application exhibits excellent synergistic catalytic performance and possesses advantages such as high activity and low cost and easy availability, making it possible for the industrial-scale catalytic synergistic removal of NOx and VOCs.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, and particularly relates to a bilayer integral synergistic catalyst for the removal of NOx and VOCs, its preparation method and applications. Background Technology

[0002] Nitrogen oxides (NOx) and volatile organic compounds (VOCs) are two important air pollutants. For example, NOx participates in ozone layer depletion and acid rain formation, while VOCs are important precursors to photochemical smog and secondary organic aerosols. Traditional treatment methods often target single pollutants, making them difficult to meet modern environmental protection requirements. Therefore, developing efficient synergistic removal technologies has become a research hotspot in recent years.

[0003] Currently, there are two main technologies for the synergistic removal of NOx and VOCs: HC-SCR technology and bifunctional oxidation-reduction technology. HC-SCR technology is more of an SCR technology that uses hydrocarbons or special organic molecules as reducing agents (abbreviated as HC-SCR technology). It can remove low-carbon hydrocarbons such as CH4, C2H4, C3H6, C3H8, and C4H4. 10 Using catalysts as reducing agents, NOx is reduced to N2. Several types of catalysts are known to promote the reduction of nitrogen oxides from hydrocarbons under lean exhaust conditions, including Cu-exchange zeolites, Pt / Al2O3, and Ag / Al2O3 catalysts. Studies have revealed several limitations in the use of these catalysts, such as: 1) low NOx conversion rates at very low organic content; 2) narrow catalyst temperature windows, unsuitable for scenarios with complex organic content; 3) low selectivity for N2 in some types of HC-SCR catalysts, potentially leading to high levels of N2O emissions; and 4) high space velocities significantly reduce NOx conversion efficiency. Therefore, these catalysts are difficult to use for the co-treatment of NOx and VOCs in complex industrial flue gas conditions.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a bilayer monolithic synergistic catalyst for the removal of NOx and VOCs, its preparation method, and its applications, in order to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A bilayer integral synergistic catalyst for the removal of NOx and VOCs includes: a support, and an inner catalyst layer and an outer catalyst layer stacked on the surface of the support;

[0008] The inner layer of the catalyst includes an oxide of a first non-noble metal and a noble metal, wherein the first non-noble metal includes one or more of Mn, V, Ti, Co, and Ce, and the noble metal includes one or more of Pt, Pd, and Rh.

[0009] The outer layer of the catalyst comprises an oxide of Cu and an oxide of a second non-noble metal, wherein the second non-noble metal comprises one or more of Mn, V, Ti, Co, and Ce.

[0010] Preferably, in the catalyst, the mass content of the first non-precious metal oxide is 10-30%, and the mass content of the precious metal is 0.03-0.12%.

[0011] In the catalyst, the mass content of Cu oxide is 0.05-0.1%, and the mass content of the second non-precious metal oxide is 5.5-10%.

[0012] Preferably, the thickness of the inner layer of the catalyst is 30-200 μm, and the thickness of the outer layer of the catalyst is 10-80 μm.

[0013] Preferably, the noble metal is Pt, and the second non-noble metal is V and Ti;

[0014] And / or,

[0015] The carrier includes one or more of cordierite carrier, silicon carbide carrier, and corundum paper.

[0016] This application also provides a method for preparing the aforementioned bilayer monolithic synergistic NOx and VOCs removal catalyst, comprising:

[0017] The first non-precious metal corresponding raw material, the precious metal corresponding raw material, the first dispersant, the first binder and ammonia water are mixed to obtain a first mixture, the carrier is impregnated in the first mixture to obtain a precursor, and the precursor is subjected to a first drying and a first calcination to obtain a single-layer monolithic catalyst.

[0018] The raw material corresponding to the second non-precious metal, the second dispersant, the second binder and ammonia water are mixed to obtain a second mixture. The single-layer monolithic catalyst is impregnated in the second mixture, and after a second drying and a second calcination, a double-layer monolithic catalyst is obtained.

[0019] The bilayer monolithic catalyst was impregnated in a copper salt solution, followed by a third drying and a third calcination to obtain the bilayer monolithic catalyst for synergistic removal of NOx and VOCs.

[0020] Preferably, the preparation method of the bilayer monolithic synergistic NOx and VOCs removal catalyst satisfies one or more of the following conditions:

[0021] (1) The first dispersant and the second dispersant each independently include one or more of polyacrylic acid, polyvinylpyrrolidone, stearic acid, polyvinyl alcohol and surface modifier; preferably polyvinyl alcohol and polyacrylic acid;

[0022] (2) The first adhesive and the second adhesive each independently include one or more of silica sol, aluminum sol, polyvinyl acetate, phenyl silicone resin and methylphenyl silicone resin; preferably a mixture of silica sol, aluminum sol and methylphenyl silicone resin;

[0023] (3) The total mass ratio of the raw material corresponding to the first non-precious metal and the precious metal raw material to the mass ratio of the first dispersant is 4.17-12.5:1;

[0024] (4) The total mass ratio of the raw material corresponding to the first non-precious metal and the precious metal raw material to the mass ratio of the first binder is 33.47-100:1;

[0025] (5) The mass ratio of the raw material corresponding to the second non-precious metal to the second dispersant is 4.16-12.48:1;

[0026] (6) The mass ratio of the raw material corresponding to the second non-precious metal to the second binder is 33.33-100:1.

[0027] Preferably, the preparation method of the bilayer monolithic synergistic NOx and VOCs removal catalyst satisfies one or more of the following conditions:

[0028] (1) The copper salt in the copper salt solution includes copper nitrate and / or copper chloride;

[0029] (2) The solvent of the copper salt solution includes an alcohol compound and water, wherein the alcohol compound includes one or more of methanol, ethanol, and isopropanol, and the mass ratio of water to the alcohol compound is (10-50):1;

[0030] (3) The copper salt in the copper salt solution accounts for 0.1-2% of the mass of the raw material corresponding to the second non-precious metal;

[0031] (4) The slurry particle size of the copper salt solution is 1-50 μm.

[0032] Preferably, the temperatures for the first drying, the second drying, and the third drying are each independently 80-150°C, and the times for each are each independently 2-5 hours;

[0033] The temperatures of the first calcination, the second calcination, and the third calcination are each independently 300-600℃, and the times are each independently 1-8h.

[0034] Preferably, the slurry particle size of the first mixture is 1-50 μm;

[0035] The particle size of the slurry in the second mixture is 0.5-30 μm.

[0036] This application also provides the use of the aforementioned bilayer integral synergistic NOx and VOCs removal catalyst for treating pollutants;

[0037] The pollutants include nitrogen oxides, alkane compounds, olefin compounds, alkyne compounds, or aromatic compounds.

[0038] The beneficial effects of this invention are:

[0039] The catalyst for the synergistic removal of NOx and VOCs provided in this application achieves synergistic removal of NOx and VOCs through a double-layer coating of inner and outer active components. The outer active component, a non-precious metal, provides water and sulfur resistance, enhancing the coating's stability and preferentially adsorbing NH3 to achieve selective catalytic reduction of NOx. The inner layer utilizes the sulfur and water resistance of the non-precious metal to provide a certain degree of stability, while the high oxidizing activity of the precious metal catalytically oxidizes VOCs. Simultaneously, N2O and NO2 diffuse into the inner layer participate in the oxidation-reduction process of VOCs, converting them into NO. The generated NO is recycled to the outer layer to participate in the SCR reaction, establishing a nitrogen oxide cycle pathway. The presence of the double-layer coating gives the catalyst a large specific surface area with wrinkled protrusions, forming a large interlayer space that facilitates molecular diffusion. This allows for the rapid desorption and transfer of byproducts generated during the reaction, preventing catalyst deactivation and thus achieving synergistic removal of NOx and VOCs. It also increases the adsorption sites for NOx and VOCs, improving overall performance. The overall catalyst preparation process is simple and easy to implement, making it highly suitable for industrial production applications.

[0040] The method for preparing a bilayer monolithic catalyst for synergistic removal of NOx and VOCs provided in this application utilizes a dispersant to inhibit sintering and a binder to strengthen the framework and improve the high-temperature durability of the catalyst. The monolithic catalyst has advantages such as high activity and low cost and easy availability, which makes it possible for industrial catalytic synergistic removal of NOx and VOCs. Attached Figure Description

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 Here is a SEM image of the bilayer monolithic catalyst obtained in Example 1;

[0043] Figure 2 The image shows a SEM image of the monolayer monolithic catalyst obtained in Comparative Example 1.

[0044] Figure 3 The performance evaluation curves of the monolithic catalyst prepared in Example 1 at different temperatures for treating toluene are shown.

[0045] Figure 4 The curves show the performance evaluation of the monolithic catalyst prepared in Example 1 at different temperatures in treating nitric oxide.

[0046] Figure 5 The stability evaluation curve is shown for the monolithic catalyst prepared in Example 1. Detailed Implementation

[0047] Before describing this application using embodiments, the technical solution provided by this application will be generally described as follows:

[0048] A bilayer integral synergistic catalyst for the removal of NOx and VOCs includes: a support, and an inner catalyst layer and an outer catalyst layer stacked on the surface of the support;

[0049] The inner layer of the catalyst includes an oxide of a first non-noble metal and a noble metal, wherein the first non-noble metal includes one or more of Mn, V, Ti, Co, and Ce, and the noble metal includes one or more of Pt, Pd, and Rh.

[0050] The outer layer of the catalyst comprises an oxide of Cu and an oxide of a second non-noble metal, wherein the second non-noble metal comprises one or more of Mn, V, Ti, Co, and Ce.

[0051] Bifunctional redox technology constructs catalytically active centers with different functions on the same catalyst, forming a dual cycle of NOx reduction and VOCs oxidation. Based on the fact that both NH3-SCR denitration and VOCs reactions are redox reactions, their reaction temperature windows overlap, and they exhibit cross-coupling and promoting effects, this paper proposes optimizing the synergistic VOCs purification efficiency through denitration catalyst regulation. By modifying with oxide doping and controlling the two-component interface, the balance between acidic sites and redox centers, and the matching between denitration active sites and VOCs oxidation active sites, are controlled, thereby constructing dual-active or multi-active catalytic centers and forming a synergistic reaction effect.

[0052] The key technologies for simultaneous purification of VOCs and NOx under low-temperature conditions are threefold: (1) By precisely controlling the oxidation performance of catalytic materials, they can achieve efficient catalytic oxidation of VOCs while effectively inhibiting the over-oxidation reaction of NH3 molecules; (2) Establishing a catalytic mechanism resistant to VOCs interference to eliminate the negative impact of gaseous VOCs components on the selective catalytic reduction (NH3-SCR) reaction activity of NH3; (3) Designing a modular structure with synergistic catalytic function, requiring the catalytic system to maintain dual-function activity in the low-temperature range (<200℃) and meet the stringent requirements of industrial catalytic devices for integral configuration, low-temperature activity window, and economical preparation process. Based on the above objectives, it is necessary to develop an integral catalyst that combines low-temperature deep oxidation of VOCs with low-temperature NH3-SCR synergistic catalytic capabilities. Its preparation process needs to achieve synergistic optimization of catalytic performance and industrial production feasibility through material component formulation optimization and structural design innovation.

[0053] In addition to successfully adapting to the above-mentioned points, the catalyst of this invention, compared with patent document 202011640788.4, utilizes the structural design of the coating to control the transport and diffusion of NH3, thereby achieving efficient synergistic removal of NOx and VOCs at low temperatures. Furthermore, compared with patent document 202211535811.2, the double-layer coating design adopted in this invention is more space-saving and cost-effective, and is more conducive to industrial application conditions.

[0054] In an optional embodiment, the catalyst contains 10-30% by mass of the oxide of the first non-precious metal and 0.03-0.12% by mass of the precious metal.

[0055] In the catalyst, the mass content of Cu oxide is 0.05-0.1%, and the mass content of the second non-precious metal oxide is 5.5-10%.

[0056] Optionally, in the catalyst, the mass content of the first non-precious metal oxide can be any value between 10%, 15%, 20%, 25%, 30%, or 10-30%, and the mass content of the precious metal can be any value between 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, or 0.03-0.12%.

[0057] In the catalyst, the mass content of Cu oxide can be any value between 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, or 0.05-0.1%, and the mass content of the second non-noble metal oxide can be any value between 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or 5.5-10%.

[0058] In one optional embodiment, the thickness of the inner catalyst layer is 30-200 μm, and the thickness of the outer catalyst layer is 10-80 μm.

[0059] By controlling the transport and diffusion of NH3 in the outer layer through thickness gradient design, NH3 is fully converted in the outer layer, thus blocking the transport of NH3 to the inner layer.

[0060] Optionally, the thickness of the inner layer of the catalyst can be any value between 30μm, 50μm, 100μm, 150μm, 200μm or 30-200μm, and the thickness of the outer layer of the catalyst can be any value between 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm or 10-80μm.

[0061] In one optional implementation, the noble metal is Pt, and the second non-noble metal is V and Ti;

[0062] And / or,

[0063] The carrier includes one or more of cordierite carrier, silicon carbide carrier, and corundum paper.

[0064] Unlike other monolithic catalysts, this catalyst uses materials such as cordierite, which have good stability and low expansion coefficient, as the matrix, and then loads non-precious metals and precious metal sources as coatings to form a bilayer monolithic catalyst.

[0065] This application also provides a method for preparing the aforementioned bilayer monolithic synergistic NOx and VOCs removal catalyst, comprising:

[0066] The first non-precious metal raw material, the precious metal raw material, the first dispersant, the first binder and ammonia water are mixed to obtain a first mixture. The carrier is impregnated in the first mixture to obtain a precursor (the slurry is in a flowing state during impregnation using a stirring device such as a stir bar or a stirring paddle; the subsequent impregnation operation is described in the same way). The precursor is subjected to a first drying and a first calcination to obtain a single-layer monolithic catalyst.

[0067] The raw material corresponding to the second non-precious metal, the second dispersant, the second binder and ammonia water are mixed to obtain a second mixture. The single-layer monolithic catalyst is impregnated in the second mixture, and after a second drying and a second calcination, a double-layer monolithic catalyst is obtained.

[0068] The bilayer monolithic catalyst was impregnated in a copper salt solution, followed by a third drying and a third calcination to obtain the bilayer monolithic catalyst for synergistic removal of NOx and VOCs.

[0069] In an optional embodiment, the preparation method of the bilayer monolithic synergistic NOx and VOCs removal catalyst satisfies one or more of the following conditions:

[0070] (1) The first dispersant and the second dispersant each independently include one or more of polyacrylic acid, polyvinylpyrrolidone, stearic acid, polyvinyl alcohol and surface modifier; preferably polyvinyl alcohol and polyacrylic acid;

[0071] (2) The first adhesive and the second adhesive each independently include one or more of silica sol, aluminum sol, polyvinyl acetate, phenyl silicone resin and methylphenyl silicone resin; preferably a mixture of silica sol, aluminum sol and methylphenyl silicone resin;

[0072] Dispersants are used to suppress particle sedimentation, while binders are used to form secondary pores. The selection of binders and dispersants controls the properties of the coating; dispersants inhibit sintering, and binders strengthen the skeleton to improve the high-temperature durability of the catalyst. Furthermore, by utilizing an improved dynamic stirring coating method (where the slurry is kept in a flowing state during impregnation using a stirrer or paddle), the NOx conversion performance was increased from 70% to 95% compared to the original static stirring coating.

[0073] (3) The total mass ratio of the raw material corresponding to the first non-precious metal and the precious metal raw material to the mass ratio of the first dispersant is 4.17-12.5:1;

[0074] Optionally, the mass ratio of the raw material corresponding to the first non-precious metal and the total mass of the precious metal raw material to the mass of the first dispersant can be any value between 4.17:1, 5:1, 10:1, 12.5:1, or 4.17-12.5:1.

[0075] (4) The total mass ratio of the raw material corresponding to the first non-precious metal and the precious metal raw material to the mass ratio of the first binder is 33.47-100:1;

[0076] Optionally, the mass ratio of the raw material corresponding to the first non-precious metal and the total mass of the precious metal raw material to the mass of the first binder can be any value between 33.47:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1 or 33.47:100:1.

[0077] (5) The mass ratio of the raw material corresponding to the second non-precious metal to the second dispersant is 4.16-12.48:1;

[0078] Optionally, the mass ratio of the raw material corresponding to the second non-precious metal to the second dispersant can be any value between 4.16:1, 5:1, 10:1, 12.48:1, or 4.16-12.48:1;

[0079] (6) The mass ratio of the raw material corresponding to the second non-precious metal to the second binder is 33.33-100:1.

[0080] Optionally, the mass ratio of the raw material corresponding to the second non-precious metal to the second binder can be any value between 33.33:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1, or 33.33:100:1.

[0081] In an optional embodiment, the preparation method of the bilayer monolithic synergistic NOx and VOCs removal catalyst satisfies one or more of the following conditions:

[0082] (1) The copper salt in the copper salt solution includes copper nitrate and / or copper chloride;

[0083] (2) The solvent of the copper salt solution includes an alcohol compound and water, wherein the alcohol compound includes one or more of methanol, ethanol, and isopropanol, and the mass ratio of water to the alcohol compound is (10-50):1;

[0084] Optionally, the mass ratio of water to alcohol can be any value between 10:1, 20:1, 30:1, 40:1, 50:1 or (10-50):1;

[0085] (3) The copper salt in the copper salt solution accounts for 0.1-2% of the mass of the raw material corresponding to the second non-precious metal;

[0086] Optionally, the copper salt in the copper salt solution accounts for any value between 0.1%, 0.5%, 1%, 1.5%, 2%, or 0.1-2% of the mass of the raw material corresponding to the second non-precious metal;

[0087] (4) The slurry particle size of the copper salt solution is 1-50 μm.

[0088] Optionally, the particle size of the copper salt solution slurry can be any value between 1μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm or 1-50μm.

[0089] In one optional implementation, the temperature of the first drying, the second drying, and the third drying are each independently 80-150°C, and the time is each independently 2-5 hours;

[0090] Optionally, the temperatures of the first drying, the second drying, and the third drying can each be independently 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃ or any value between 80℃ and 150℃, and the times can each be independently 2h, 3h, 4h, 5h or any value between 2-5h;

[0091] The temperatures of the first calcination, the second calcination, and the third calcination are each independently 300-600℃, and the times are each independently 1-8h.

[0092] Optionally, the temperatures of the first calcination, the second calcination, and the third calcination can each be independently any value between 300℃, 400℃, 500℃, 600℃, or 300-600℃, and the times can each be independently any value between 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, or 1-8h.

[0093] In one optional embodiment, the slurry particle size of the first mixture is 1-50 μm;

[0094] The particle size of the slurry in the second mixture is 0.5-30 μm.

[0095] Optionally, the particle size of the first mixture can be any value between 1μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm or 1-50μm; the particle size of the second mixture can be any value between 0.5μm, 1μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm or 0.5-30μm.

[0096] The pore structure of the coating is controlled by the particle size of the slurry, the thickness of the coating, and the types of binders and dispersants, allowing small VOC molecules (such as toluene) and reaction byproducts N2O and NO2 to diffuse into the interior, but blocking the transport of NH3.

[0097] This application also provides the use of the aforementioned bilayer integral synergistic NOx and VOCs removal catalyst for treating pollutants;

[0098] The pollutants include nitrogen oxides, alkane compounds, olefin compounds, alkyne compounds, or aromatic compounds.

[0099] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0100] Example 1

[0101] This embodiment provides a bilayer monolithic catalyst for the synergistic removal of NOx and VOCs, and its preparation method is as follows:

[0102] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0103] (2) Weigh 63.09g of deionized water, 2.53g of dispersant polyvinyl alcohol, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cerium nitrate, 2.53g of Maclean alkaline silica sol, 0.3155g of binder methylphenyl silicone resin, adjust the pH to 7 with ammonia water, stir overnight to make solution A (particle size 50μm);

[0104] (3) Weigh 63.09g of deionized water, 2.53g of dispersant polyvinyl alcohol, 10.53g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of Maclean alkaline silica sol, 0.3155g of binder methyl phenyl silicone resin, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 30μm);

[0105] (3) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them as C solution (particle size 1μm);

[0106] (4) Weigh 1.2g of 10%wt Pt(NO3)2 solution, add it to solution A, and obtain solution D (particle size 50μm);

[0107] (5) Then, the pretreated 1×1×1cm regular cordierite carrier (0.5g of blank cordierite) is immersed in solution D for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here) to obtain precursor D;

[0108] (6) The precursor D was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst E (mass of monolayer catalyst 0.603 g).

[0109] (7) Impregnate the monolayer monolithic catalyst in solution B to obtain precursor F;

[0110] (8) Precursor F was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain precursor G.

[0111] (9) After immersing the precursor G in Cu solution for 30 seconds, drying it at 80°C for 2 hours, and then calcining it in a muffle furnace at 500°C for 3 hours, an outer layer of approximately 30 μm was obtained. (Immersion in Cu solution has no effect on coating thickness; see details...) Figure 1 The inner layer is approximately 70μm (see details). Figure 1 A bilayer monolithic catalyst (bilayer catalyst mass 0.647 g) was used. Its SEM image is shown below. Figure 1 As shown.

[0112] Example 2

[0113] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0114] (2) Weigh 63.09g of deionized water, 2.53g of dispersant polyvinyl alcohol, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 3.1g of cerium nitrate, 2.53g of Maclean alkaline silica sol, 0.3155g of binder methylphenyl silicone resin, adjust the pH to 7 with ammonia water, stir overnight to make solution A (particle size 50μm);

[0115] (3) Weigh 63.09g of deionized water, 2.53g of dispersant polyvinyl alcohol, 10.53g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of Maclean alkaline silica sol, 0.3155g of binder methyl phenyl silicone resin, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 30μm);

[0116] (3) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them as C solution (particle size 1μm);

[0117] (4) Weigh 2.4g of 10%wt Pt(NO3)2 solution, add it to solution A, and obtain solution D (particle size 50μm);

[0118] (5) Then, the pretreated 1×1×1cm regular cordierite carrier (0.5g blank cordierite) is immersed in solution D for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here) to obtain precursor D;

[0119] (6) The precursor D was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst E (mass of monolayer catalyst 0.606 g).

[0120] (7) Impregnate the monolayer monolithic catalyst in solution B to obtain precursor F;

[0121] (8) Precursor F was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain precursor G.

[0122] (9) After impregnating the precursor G in C solution for 30s, drying it at 80℃ for 2h, and then calcining it in a muffle furnace at 500℃ for 3h, a bilayer monolithic catalyst with an outer layer of about 30μm (the impregnation of Cu solution has no effect on the coating thickness) and an inner layer of about 100μm was obtained (the mass of the bilayer catalyst is 0.65g).

[0123] Example 3

[0124] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0125] (2) Weigh 63.09g of deionized water, 2.53g of dispersant polyvinyl alcohol, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cerium nitrate, 2.53g of Maclean alkaline silica sol, 0.3155g of binder methylphenyl silicone resin, adjust the pH to 7 with ammonia water, stir overnight to make solution A (particle size 50μm);

[0126] (3) Weigh 63.09g of deionized water, 2.53g of polyvinyl alcohol dispersant, 15.79g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of Maclean alkaline silica sol, 0.3155g of methyl phenyl silicone resin binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 30μm);

[0127] (3) Weigh 3.1g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them to make solution C (particle size 1μm);

[0128] (4) Weigh 1.2g of 10%wt Pt(NO3)2 solution, add it to solution A, and obtain solution D (particle size 50μm);

[0129] (5) Then, the pretreated 1×1×1cm regular cordierite carrier (0.5g of blank cordierite) is immersed in solution D for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here) to obtain precursor D;

[0130] (6) The precursor D was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst E (mass of monolayer catalyst 0.603 g).

[0131] (7) Impregnate the monolayer monolithic catalyst in solution B to obtain precursor F;

[0132] (8) Precursor F was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain precursor G.

[0133] (9) After impregnating the precursor G in C solution for 30s, drying it at 80℃ for 2h, and then calcining it in a muffle furnace at 500℃ for 3h, a bilayer monolithic catalyst with an outer layer of about 50μm (the impregnation of Cu solution has no effect on the coating thickness) and an inner layer of about 70μm was obtained (the mass of the bilayer catalyst is 0.651g).

[0134] Comparative Example 1

[0135] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0136] (2) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cerium nitrate, 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as A (particle size 50μm);

[0137] (3) Weigh 1.2g of 10%wt Pt(NO3)2 solution, add it to solution A to obtain solution B (particle size 30μm);

[0138] (4) Then, the pretreated 1×1×1cm regular cordierite carrier (0.5g of blank cordierite; the same mass of regular cordierite in the comparative example) was immersed in solution B for 30s (during immersion, the slurry was kept in a flowing state by using a stirring device such as a stir bar or stirring paddle) to obtain precursor C.

[0139] (5) After drying the precursor C at 80℃ for 2 hours, it was calcined in a muffle furnace at 500℃ for 3 hours to obtain a monolayer monolithic catalyst D (inner layer only, mass 0.603 g), and its SEM image is shown below. Figure 2 As shown.

[0140] Comparative Example 2

[0141] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0142] (2) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, and stir overnight to make solution A (particle size 50μm);

[0143] (3) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them as solution B;

[0144] (4) Then, the pretreated 1×1×1cm regular cordierite carrier is immersed in solution A for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle) to obtain precursor C.

[0145] (5) The precursor C was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst D (outer layer only, mass 0.544 g).

[0146] Comparative Example 3

[0147] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0148] (2) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cerium nitrate, 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution A (particle size 50μm);

[0149] (3) Weigh 63.09g of deionized water, 2.53g of dispersant, 10.53g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 0.5265g of cerium nitrate, 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 30μm);

[0150] (4) Weigh 2.4g of 10%wt Pt(NO3)2 solution, add it to solution A, and obtain solution C (particle size 50μm);

[0151] (5) Weigh 1.2g of 10%wt Pt(NO3)2 solution, add it to solution B, and obtain solution D (particle size 30μm);

[0152] (6) Then, the pretreated 1×1×1cm regular cordierite carrier is immersed in solution B for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here), to obtain precursor E;

[0153] (6) The precursor E was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst F (the mass of the monolayer catalyst is 0.606 g).

[0154] (7) Impregnate the monolayer monolithic catalyst in liquid C to obtain precursor G;

[0155] (9) The precursor G was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a bilayer monolithic catalyst (0.652 g of bilayer catalyst).

[0156] Comparative Example 4

[0157] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0158] (2) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution A (particle size 50μm);

[0159] (3) Weigh 63.09g of deionized water, 2.53g of dispersant, 10.53g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 30μm);

[0160] (4) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them to make solution C;

[0161] (5) Then, the pretreated 1×1×1cm regular cordierite carrier is immersed in solution A for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here), to obtain precursor D;

[0162] (6) The precursor D was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst E (mass of monolayer catalyst 0.6 g).

[0163] (7) Impregnate the monolayer monolithic catalyst in liquid C to obtain precursor F;

[0164] (8) The precursor F was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain catalyst G (catalyst mass 0.604 g).

[0165] (9) The catalyst G was impregnated in solution B to obtain precursor H;

[0166] (10) The precursor H was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain catalyst I (catalyst mass 0.644 g).

[0167] (11) Impregnate catalyst I in liquid C to obtain precursor J;

[0168] (12) The precursor J was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain the monolithic catalyst K (catalyst mass 0.648 g).

[0169] Comparative Example 5

[0170] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0171] (2) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cerium nitrate, 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution A (particle size 50μm);

[0172] (3) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 50μm);

[0173] (3) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them to make solution C;

[0174] (4) Weigh 1.2g of 10%wt Pt(NO3)2 solution, add it to solution A, and obtain solution D (particle size 50μm);

[0175] (5) Then, the pretreated 1×1×1cm regular cordierite carrier is immersed in solution D for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here), to obtain precursor E;

[0176] (6) The precursor E was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst F (catalyst mass 0.603 g).

[0177] (7) Impregnate the monolayer monolithic catalyst in solution B to obtain precursor G;

[0178] (8) The precursor G was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain the precursor H.

[0179] (9) After impregnating the precursor H in C solution for 30s, drying it at 80℃ for 2h, and then calcining it in a muffle furnace at 500℃ for 3h, a bilayer monolithic catalyst with an outer layer thickness (the impregnation of Cu solution has no effect on the coating thickness) is obtained with an inner layer thickness of 0.707g.

[0180] Comparative Example 6

[0181] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0182] (2) Weigh 63.09g of deionized water, 2.53g of stearic acid, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cerium nitrate, 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution A (particle size 50μm);

[0183] (3) Weigh 63.09g of deionized water, 2.53g of polyvinylpyrrolidone, 10.53g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use it as solution B (particle size 30μm).

[0184] (4) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them to make solution C;

[0185] (5) Weigh 1.2g of 10%wt Pt(NO3)2 solution, add it to solution A, and obtain solution D (particle size 50μm);

[0186] (6) Then, the pretreated 1×1×1cm regular cordierite carrier is immersed in solution D for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here), to obtain precursor E;

[0187] (7) The precursor E was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst F (catalyst mass 0.703 g).

[0188] (8) Impregnate the monolayer monolithic catalyst in solution B to obtain precursor G;

[0189] (9) The precursor G was dried at 80°C for 2 hours and then calcined in a muffle furnace at 500°C for 3 hours to obtain the precursor H.

[0190] (10) After the precursor H was immersed in liquid C for 30s, it was dried at 80℃ for 2h and then calcined in a muffle furnace at 500℃ for 3h to obtain a bilayer monolithic catalyst (catalyst mass 0.767g).

[0191] Comparative Example 7

[0192] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0193] (2) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cerium nitrate, 2.53g of silica sol, 0.3155g of phenyl silicone resin, adjust the pH to 7 with ammonia water, stir overnight and use as solution A (particle size 50μm);

[0194] (3) Weigh 63.09g of deionized water, 2.53g of dispersant, 10.53g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of silica sol, 0.3155g of phenyl silicone resin, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 30μm);

[0195] (4) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them to make solution C;

[0196] (5) Weigh 1.2g of 10%wt Pt(NO3)2 solution, add it to solution A, and obtain solution D (particle size 50μm);

[0197] (6) Then, the pretreated 1×1×1cm regular cordierite carrier is immersed in solution D for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here), to obtain precursor E;

[0198] (7) The precursor E was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst F (catalyst mass 0.653 g).

[0199] (8) Impregnate the monolayer monolithic catalyst in solution B to obtain precursor G;

[0200] (9) The precursor G was dried at 80°C for 2 hours and then calcined in a muffle furnace at 500°C for 3 hours to obtain the precursor H.

[0201] (10) After impregnating the precursor G in liquid C for 30s, drying it at 80℃ for 2h, and then calcining it in a muffle furnace at 500℃ for 3h, a bilayer monolithic catalyst (catalyst mass 0.717g) was obtained.

[0202] Comparative Example 8

[0203] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0204] (2) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cobalt nitrate, 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution A (particle size 50μm);

[0205] (3) Weigh 63.09g of deionized water, 2.53g of dispersant, 10.53g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 30μm);

[0206] (4) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them to make solution C;

[0207] (5) Weigh 1.2g of 10%wt Pt(NO3)2 solution, add it to solution A, and obtain solution D (particle size 50μm);

[0208] (6) Then, the pretreated 1×1×1cm regular cordierite carrier is immersed in solution D for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here), to obtain precursor D;

[0209] (7) The precursor D was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst E (catalyst mass 0.603 g).

[0210] (8) Impregnate the monolayer monolithic catalyst in solution B to obtain precursor F;

[0211] (9) The precursor F was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain the precursor G.

[0212] (10) After impregnating the precursor G in C solution for 30s, drying it at 80℃ for 2h, and then calcining it in a muffle furnace at 500℃ for 3h, a bilayer monolithic catalyst with an outer layer of 70μm (the impregnation of Cu solution has no effect on the coating thickness) and an inner layer of 80μm was obtained (catalyst mass 0.647g).

[0213] Comparative Example 9

[0214] (1) Ball milling of vanadium-titanium powder for 2 hours.

[0215] (2) Weigh 63.09g of deionized water, 2.53g of dispersant, 31.55g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 1.5775g of cerium nitrate, 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution A (particle size 50μm);

[0216] (4) Weigh 63.09g of deionized water, 2.53g of dispersant, 10.53g of vanadium-titanium powder (vanadium-titanium mass ratio of 5:95), 2.53g of silica sol, 0.3155g of binder, adjust the pH to 7 with ammonia water, stir overnight and use as solution B (particle size 30μm);

[0217] (5) Weigh 1.5775g of Cu(NO3)2, 20mL of C2H5OH, and 50mL of H2O, and stir to mix them to make solution C;

[0218] (6) Weigh 1.2g of 10%wt Rh(NO3)2 solution, add it to solution A, and obtain solution D (particle size 50μm);

[0219] (7) Then, the pretreated 1×1×1cm regular cordierite carrier is immersed in solution D for 30s (during immersion, the slurry is kept in a flowing state by using a stirring device such as a stir bar or stirring paddle; the subsequent immersion operation is the same as here), to obtain precursor D;

[0220] (8) The precursor D was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain a monolayer monolithic catalyst E (catalyst mass 0.603 g).

[0221] (9) Impregnate the monolayer monolithic catalyst in solution B to obtain precursor F;

[0222] (10) Precursor F was dried at 80°C for 2 hours and then calcined at 500°C for 3 hours in a muffle furnace to obtain precursor G.

[0223] (11) After impregnating the precursor G in C solution for 30s, drying it at 80℃ for 2h, and then calcining it in a muffle furnace at 500℃ for 3h, a bilayer monolithic catalyst with an outer layer of 70μm (the impregnation of Cu solution has no effect on the coating thickness) and an inner layer of 80μm was obtained (catalyst mass 0.647g).

[0224] The monolithic catalyst prepared above was used in a fixed-bed reaction. The mixed gas contained the following atmosphere: 800 ppm NO; 100 ppm SO2; 500 ppm CH4; 250 ppm C2H6; 250 ppm C3H8; 100 ppm C2H4; 30 ppm C6H6; 20 ppm C7H8; 5% CO2; 10% H2O; 2500 ppm CO; 10% O2; 800 ppm NH3; and N2 as the balance gas. The test was conducted at 250℃ and a space velocity of 15000 mL / g*h. After stabilization, the concentrations of NOx and VOCs in the gas at the reactor inlet and outlet were measured, and the conversion rate was calculated as (NOx and VOCs concentration at reactor inlet - NOx and VOCs concentration at reactor outlet) / (NOx and VOCs concentration at reactor inlet) x 100%. The test data are shown in Table 1 below.

[0225] Table 1 Conversion Rate Data

[0226] Example 1 90 100 Example 2 88 100 Example 3 92 98 Comparative Example 1 78 100 Comparative Example 2 92 85 Comparative Example 3 77 100 Comparative Example 4 93 86 Comparative Example 5 93 82 Comparative Example 6 76 80 Comparative Example 7 74 82 Comparative Example 8 72 100 Comparative Example 9 80 100

[0227] The performance of the monolithic catalyst prepared in Example 1 in treating toluene and nitric oxide at different temperatures was evaluated, and the results are as follows: Figure 3 and Figure 4 As shown. The stability of the monolithic catalyst prepared in Example 1 was evaluated, and the results are as follows. Figure 5 As shown.

[0228] As shown in Table 1 above, in Comparative Examples 1 and 2, the monolayer catalysts have a single effective effect on NO or C7H8; in Comparative Examples 3 and 4, the conversion of NO or C7H8 can be enhanced by adding Pt or Cu; Comparative Example 5 shows that there is a gradient ratio between the thickness of the outer and inner layers in this test; Comparative Examples 6 and 7 show that the types of dispersants and binders have an important impact on the performance of this catalyst; Comparative Examples 8 and 9 show that the combination of different elements will produce different reduction and oxidation effects.

[0229] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A bilayer integral synergistic catalyst for the removal of NOx and VOCs, characterized in that, include: The support, and the inner and outer catalyst layers stacked on the surface of the support; The inner layer of the catalyst includes an oxide of a first non-noble metal and a noble metal, wherein the first non-noble metal includes one or more of Mn, V, Ti, Co, and Ce, and the noble metal includes one or more of Pt, Pd, and Rh. The outer layer of the catalyst comprises an oxide of Cu and an oxide of a second non-noble metal, wherein the second non-noble metal comprises one or more of Mn, V, Ti, Co, and Ce. In the catalyst, the mass content of the first non-precious metal oxide is 10-30%, and the mass content of the precious metal is 0.03-0.12%. In the catalyst, the mass content of Cu oxide is 0.05-0.1%, and the mass content of the second non-precious metal oxide is 5.5-10%. The thickness of the inner layer of the catalyst is 30-200 μm, and the thickness of the outer layer of the catalyst is 10-80 μm; The preparation method of the bilayer monolithic synergistic NOx and VOCs removal catalyst includes: mixing the raw material corresponding to the first non-precious metal, the raw material corresponding to the precious metal, the first dispersant, the first binder and ammonia water to obtain a first mixture; impregnating the support in the first mixture to obtain a precursor; during impregnation, the first mixture is in a flowing state using a stirring device; and subjecting the precursor to a first drying and a first calcination to obtain a single-layer monolithic catalyst. The raw material corresponding to the second non-precious metal, the second dispersant, the second binder and ammonia water are mixed to obtain a second mixture. The single-layer monolithic catalyst is impregnated in the second mixture. During impregnation, the second mixture is in a flowing state using a stirring device. After a second drying and a second calcination, a double-layer monolithic catalyst is obtained. The bilayer monolithic catalyst was impregnated in a copper salt solution, followed by a third drying and a third calcination to obtain the bilayer monolithic catalyst for synergistic removal of NOx and VOCs.

2. The catalyst for the bilayer integral synergistic removal of NOx and VOCs according to claim 1, characterized in that, The noble metal is Pt, and the second non-noble metal is V and Ti; And / or, The carrier includes one or more of cordierite carrier, silicon carbide carrier, and corundum paper.

3. A method for preparing a bilayer monolithic synergistic catalyst for NOx and VOCs removal as described in claim 1 or 2, characterized in that, The first dispersant and the second dispersant each independently include one or more of polyacrylic acid, polyvinylpyrrolidone, stearic acid, polyvinyl alcohol, and surface modifiers; The first adhesive and the second adhesive each independently include one or more of silica sol, aluminum sol, polyvinyl acetate, phenyl silicone resin and methylphenyl silicone resin; The total mass ratio of the raw material corresponding to the first non-precious metal and the precious metal raw material to the mass ratio of the first dispersant is 4.17-12.5:1; The mass ratio of the raw material corresponding to the first non-precious metal and the total mass of the precious metal raw material to the mass of the first binder is 33.47-100:1; The mass ratio of the raw material corresponding to the second non-precious metal to the second dispersant is 4.16-12.48:1; The mass ratio of the raw material corresponding to the second non-precious metal to the second binder is 33.33-100:

1.

4. The method for preparing the bilayer integral synergistic removal catalyst for NOx and VOCs according to claim 3, characterized in that, One or more of the following conditions must be met: (1) The copper salt in the copper salt solution includes copper nitrate and / or copper chloride; (2) The solvent of the copper salt solution includes an alcohol compound and water, wherein the alcohol compound includes one or more of methanol, ethanol, and isopropanol, and the mass ratio of water to the alcohol compound is (10-50):1; (3) The copper salt in the copper salt solution accounts for 0.1-2% of the mass of the raw material corresponding to the second non-precious metal; (4) The slurry particle size of the copper salt solution is 1-50 μm.

5. The method for preparing the bilayer integral synergistic removal catalyst for NOx and VOCs according to claim 3, characterized in that, The temperatures for the first drying, the second drying, and the third drying are each independently 80-150℃, and the times for each are each independently 2-5 hours; The temperatures of the first calcination, the second calcination, and the third calcination are each independently 300-600℃, and the times are each independently 1-8h.

6. The method for preparing the bilayer monolithic synergistic NOx and VOCs removal catalyst according to any one of claims 3-5, characterized in that, The particle size of the slurry in the first mixture is 1-50 μm; The particle size of the slurry in the second mixture is 0.5-30 μm.

7. The use of a bilayer monolithic synergistic catalyst for the removal of NOx and VOCs as described in claim 1 or 2, characterized in that, Used to treat pollutants; The pollutants include nitrogen oxides, alkane compounds, olefin compounds, alkyne compounds, or aromatic compounds.

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