Dual-supported integral catalytic oxidation catalyst and preparation method thereof

Abstract

The invention provides a dual-supported integral catalytic oxidation catalyst and a preparation method thereof. The catalyst comprises a catalyst substrate and a catalyst coating coated on the surface of the catalyst substrate; the catalyst coating comprises a catalyst carrier, and a first active component, a second active component and a nano curing agent which are loaded on the catalyst carrier; the mass ratio of the first active component to the second active component is (0.5-40): 1. By optimizing the type of metal loaded on the catalyst carrier and the surface structure of the catalyst, the problem of short service life of the catalyst caused by poisoning failure of the second active component, the carrier and other components in the catalyst is solved, and the problems of poor activity under a moisture-containing condition and the like caused by difficult surface hydrophobic modification and poor uniformity of the traditional catalyst are solved; the application range of the catalyst under complex working conditions is widened; the volatilization of a second active component intermediate formed in the catalytic reaction process is inhibited, so that the service life of the catalyst is prolonged.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of catalysts, and relates to a catalytic oxidation catalyst, in particular to a double-loaded monolithic catalytic oxidation catalyst and a preparation method thereof. BACKGROUND

[0002] As a method for purifying volatile organic compounds (VOCs) efficiently, catalytic combustion technology has been widely applied in the treatment of organic waste gas in many industries such as steel, chemical industry, pharmaceutical industry and the like. However, the waste gas in the above-mentioned industries contains components such as sulfur and halogen, which are easy to cause catalyst poisoning, resulting in the reduction of the service life of the catalyst. At present, most catalyst manufacturers prolong the service life of the catalyst by increasing the amount of noble metal or using double / multi-component noble metal, but the price is high, and the research and application of other active additives are ignored, and these additives have potential value in enhancing the anti-poisoning ability, improving the water resistance and reducing the cost.

[0003] CN 111215122A discloses a palladium-based methane catalytic combustion catalyst and a preparation and application thereof, and the preparation method comprises the following steps: (1) mixing a Pd salt aqueous solution and a surfactant, adding a reducing agent under stirring to obtain Pd sol nano-particles protected by the surfactant; (2) adding a mesoporous molecular sieve to the Pd sol nano-particle solution, adjusting the pH value of the solution to 1-5 with an acid, and stirring for 1-12 hours; (3) filtering, washing, drying and calcining the mixture obtained in the step (2) to obtain a Pd nano-catalyst loaded on the mesoporous molecular sieve with a Pd mass fraction of 0.1-10%. The catalyst exhibits excellent low-temperature catalytic activity and high-temperature sintering resistance for the catalytic combustion reaction of methane; but Pd is easy to form PdSO4 in a sulfur-containing atmosphere, resulting in the reduction of the catalyst activity and the decline of the performance.

[0004] CN 103831104A discloses a monolithic Pd-Pt catalyst for purifying industrial organic waste gas and a preparation method thereof. The catalyst comprises cerium-rich mixed rare earth oxides, Al2O3, SiO2, K, noble metals Pd and Pt, and a cordierite honeycomb ceramic carrier. The cerium-rich mixed rare earth oxides, pseudo-boehmite binder and acidic silica sol are coated on the surface of the cordierite honeycomb ceramic carrier; then KOH is further loaded; finally, the catalyst is prepared by loading the noble metals Pd and Pt through the impregnation method. The catalyst can prevent surface carbon, has good thermal stability, high catalyst coating adhesion strength and good activity; but Pt is easy to be converted into PtO2 in a chlorine-containing atmosphere, resulting in the volatilization of the noble metal and the deactivation of the catalyst. x Cl y

[0005] In view of the above, it is necessary to provide a monolithic catalytic oxidation catalyst with excellent catalytic effect and long service life. SUMMARY​

[0006] In view of the deficiencies of the prior art, the present application aims to provide a dual-load monolithic catalytic oxidation catalyst and a preparation method thereof. In the present application, the first active component loaded on the catalyst carrier can adsorb or react with the sulfur-containing and halogen-containing components in the flue gas, thereby avoiding rapid poisoning and failure of the second active component, the carrier and other components, prolonging the service life of the catalyst and realizing stable operation. In addition, the first active component can promote the adsorption, activation and dissociation of water molecules, improve the ability to remove VOCs / CO synergistically, overcome the problems of poor hydrophobic modification and poor uniformity of the surface of traditional catalysts, which leads to poor activity under humid conditions, and broaden the application of the catalyst under complex working conditions.

[0007] To achieve the object of the present application, the following technical solutions are adopted:

[0008] In a first aspect, the present application provides a dual-load monolithic catalytic oxidation catalyst, which comprises a catalyst substrate and a catalyst carrier coated on the surface of the catalyst substrate.

[0009] The catalyst coating layer comprises a catalyst carrier, and a first active component, a second active component and a nano-solidification agent loaded on the catalyst carrier. The mass ratio of the first active component and the second active component is 0.5-40:1, for example, it can be 0.5:1, 1:1, 5:1, 10:1, 20:1, 30:1 or 40:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0010] The monolithic catalytic oxidation catalyst of the present application is loaded with a first active component and a second active component. The first active component can adsorb or react with the sulfur-containing and halogen-containing components in the flue gas to be treated, thereby avoiding rapid poisoning and failure of the second active component, the carrier and other components, prolonging the service life of the catalyst and realizing stable operation. In addition, under high-humidity flue gas, the first active component can promote the adsorption, activation and dissociation of water molecules, improve the ability to remove VOCs / CO synergistically, overcome the problems of poor hydrophobic modification and poor uniformity of the surface of traditional catalysts, which leads to poor activity under humid conditions, and broaden the application of the catalyst under complex working conditions. The nano-solidification agent can inhibit the volatilization of the intermediate of the second active component formed during the catalytic reaction, further prolonging the service life of the catalyst.

[0011] As a preferred technical solution of the present application, the first active component comprises copper and / or cerium metal elements.

[0012] Preferably, the second active component comprises a metal element of any one or at least two combinations of ruthenium, palladium or platinum, typical but non-limiting combinations of metal elements include: a combination of ruthenium and palladium, a combination of ruthenium and platinum, a combination of palladium and platinum, or a combination of ruthenium, palladium and platinum.

[0013] Preferably, the catalyst substrate comprises mullite or cordierite.

[0014] The catalyst substrate of the present application is a honeycomb substrate, which can provide more loading sites for the catalyst carrier, and further improve the catalytic efficiency.

[0015] Preferably, the catalyst carrier comprises any one or at least two combinations of molecular sieve, titanium dioxide or cerium oxide, typical but non-limiting combinations include: a combination of molecular sieve and titanium dioxide, a combination of molecular sieve and cerium oxide, a combination of titanium dioxide and cerium oxide, or a combination of molecular sieve, titanium dioxide and cerium oxide.

[0016] Preferably, the second active component is 0.01-1.6% of the total mass of the catalyst, for example, it can be 0.01%, 0.05%, 0.1%, 0.5%, 1%, 1.3% or 1.6%, etc., but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0017] Preferably, the first active component is 0.5-10% of the total mass of the catalyst, for example, it can be 0.5%, 1%, 2%, 4%, 6%, 8% or 10%, etc., but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0018] In a second aspect, the present application provides a preparation method of the dual-support monolithic catalytic oxidation catalyst as provided in the first aspect, the preparation method comprising the following steps:

[0019] (1) mixing the catalyst carrier and deionized water, uniformly ultrasonicating, then mixing the first active component precursor, and then sequentially performing stirring, drying, first homogenization treatment and first thermal activation treatment to obtain a multifunctional composite matrix;

[0020] (2) mixing the deionized water and the multifunctional composite matrix obtained in step (1), uniformly ultrasonicating, then mixing the second active component precursor, and then sequentially performing stirring, drying and second thermal activation treatment to obtain a catalyst powder;

[0021] (3) mixing the deionized water and the catalyst powder obtained in step (2), stirring, then mixing a nano-solidification liquid, and then performing second homogenization treatment to obtain a turbid liquid;

[0022] (4) immersing the catalyst substrate into the turbid solution as described in step (3), and then sequentially performing purging treatment, drying and third thermal activation treatment to obtain the monolithic catalytic oxidation catalyst.

[0023] In the present application, the first active component and the second active component are dispersed in the internal and external pore channel surface of the catalyst carrier by homogenization and thermal activation technology to form a monolithic catalytic oxidation catalyst; in the catalytic process, the first active component can be sacrificed to prolong the service life of the catalyst, and the problems of poor hydrophobic modification and poor uniformity of the traditional catalyst surface, which leads to poor activity under humid conditions, are overcome, and the application of the catalyst under complex working conditions is widened;

[0024] In addition, a physical solidification layer is formed on the surface of the catalyst by using a nano-solidification liquid, thereby inhibiting the volatilization of the intermediate of the second active component formed in the reaction process, and further prolonging the service life of the catalyst.

[0025] Preferably, the first active component precursor in step (1) includes any one or a combination of at least two of copper nitrate, copper acetate or cerium nitrate, and typical but non-limiting combinations include: a combination of copper nitrate and copper acetate, a combination of copper nitrate and cerium nitrate, a combination of copper acetate and cerium nitrate, or a combination of copper nitrate, copper acetate and cerium nitrate.

[0026] Preferably, the mass ratio of the first active component precursor to the catalyst carrier is 0.05-20:1, for example, it can be 0.05:1, 0.1:1, 1:1, 5:1, 10:1, 15:1 or 20:1, etc., but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0027] As a preferred technical solution of the present application, the stirring time in step (1) is 12-24h, for example, it can be 12h, 14h, 16h, 18h, 20h, 22h or 24h, etc., but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0028] Preferably, the first homogenization treatment in step (1) is performed for 0.5-2h, for example, it can be 0.5h, 0.8h, 1.1h, 1.4h, 1.7h or 2h, etc., but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0029] Preferably, the temperature of the first thermal activation treatment in step (1) is 400-700℃, for example, it can be 400℃, 450℃, 500℃, 550℃, 600℃, 650℃ or 700℃, etc., but is not limited to the listed values, and other values not listed within the value range are also applicable.

[0030] Preferably, the first thermal activation treatment in step (1) is performed for 2-5 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours, but not limited to the listed values, and other values not listed within the value range are also applicable.

[0031] In the present application, the first active component is uniformly loaded on the surface and pores of the catalyst carrier through the first homogenization treatment and the first thermal activation treatment.

[0032] As a preferred technical solution of the present application, the second active component precursor in step (2) includes any one or a combination of at least two of ruthenium chloride, nitrosyl nitrate ruthenium, chloroplatinic acid, tetraammine platinum chloride, platinum nitrate, tetraammine platinum nitrate, palladium chloride, palladium nitrate, or tetraammine palladium nitrate. Typical but non-limiting combinations include: a combination of ruthenium chloride and nitrosyl nitrate ruthenium, a combination of chloroplatinic acid, tetraammine platinum chloride, platinum nitrate, and tetraammine platinum nitrate, a combination of palladium chloride, palladium nitrate, and tetraammine palladium nitrate, a combination of ruthenium chloride, chloroplatinic acid, and palladium chloride, or a combination of nitrosyl nitrate ruthenium, tetraammine platinum nitrate, and tetraammine palladium nitrate.

[0033] Preferably, the mass ratio of the second active component precursor to the multifunctional composite matrix is 0.005-0.45:1, for example, 0.005:1, 0.01:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1, or 0.45:1, but not limited to the listed values, and other values not listed within the value range are also applicable.

[0034] Preferably, the second thermal activation treatment in step (2) is performed at a temperature of 400-600°C, for example, 400°C, 440°C, 480°C, 520°C, 560°C, or 600°C, but not limited to the listed values, and other values not listed within the value range are also applicable.

[0035] Preferably, the second thermal activation treatment in step (2) is performed for 2-5 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours, but not limited to the listed values, and other values not listed within the value range are also applicable.

[0036] In the present application, the second active component is loaded on the catalyst carrier through the second thermal activation treatment. If the temperature of the second thermal activation treatment is too low, the active component cannot be formed on the catalyst carrier. If the temperature is too high, the active tungsten powder will volatilize or sublimate, thereby affecting the catalytic efficiency of the catalyst.

[0037] As a preferred technical solution of the present application, the nano-solidification liquid in step (3) includes acidic or alkaline silica sol.

[0038] Preferably, the mass ratio of the nanosolidification liquid and the catalyst powder is 0.02-1:1, for example, it can be 0.02:1, 0.05:1, 0.1:1, 0.2:1, 0.4:1, 0.6:1, 0.8:1 or 1:1, etc., but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0039] Preferably, the time of the second homogenization treatment in step (3) is 0.5-4h, for example, it can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h, etc., but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0040] As a preferred technical solution of the present application, the step (4) further comprises a pretreatment of the catalyst substrate before immersion.

[0041] Preferably, the pretreatment comprises soaking the catalyst substrate with an alkali solution, and then sequentially washing with deionized water and drying.

[0042] Preferably, the alkali solution comprises sodium hydroxide and / or potassium hydroxide.

[0043] Preferably, the concentration of the alkali solution is 10-20wt%, for example, it can be 10wt%, 12wt%, 14wt%, 16wt%, 18wt% or 20wt%, etc., but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0044] Preferably, the soaking treatment time is 30-60min, for example, it can be 30min, 35min, 40min, 45min, 50min, 55min or 60min, etc., but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0045] Preferably, the soaking treatment temperature is 30-40℃, for example, it can be 30℃, 32℃, 34℃, 36℃, 38℃ or 40℃, etc., but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0046] As a preferred technical solution of the present application, the temperature of the third heat activation treatment in step (4) is 400-600℃, for example, it can be 400℃, 440℃, 480℃, 520℃, 560℃ or 600℃, etc., but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0047] Preferably, the third heat activation treatment in step (4) has a time of 2-5h, such as 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5h, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0048] Preferably, the purging treatment in step (4) is positive pressure purging for removing residual liquid.

[0049] The third heat activation treatment in the present application is used for the solidification forming of the monolithic catalytic oxidation catalyst, and the formation of the physical solidification layer is achieved by introducing the nano solidification liquid, thereby inhibiting the volatilization of the noble metal intermediate formed in the reaction process; if the temperature of the third heat activation treatment is too high, the active component will volatilize and be lost; and if the temperature is too low, the catalyst coating will fall off.

[0050] As a preferred technical solution of the present application, the preparation method of the double-loaded monolithic catalytic oxidation catalyst according to the second aspect of the present application comprises the following steps:

[0051] (1) mixing the catalyst carrier and deionized water, uniformly ultrasonicating, then mixing the first active component precursor, and then sequentially performing stirring for 12-24h, drying, first homogenization treatment for 0.5-2h, and first heat activation treatment to obtain a multifunctional composite matrix;

[0052] wherein the mass ratio of the first active component precursor to the catalyst carrier is 0.05-20:1; the temperature of the first heat activation treatment is 400-700℃, and the time is 2-5h;

[0053] (2) mixing deionized water and the multifunctional composite matrix obtained in step (1), uniformly ultrasonicating, then mixing the second active component precursor, and then sequentially performing stirring, drying, and second heat activation treatment to obtain a catalyst powder;

[0054] wherein the mass ratio of the second active component precursor to the multifunctional composite matrix is 0.005-0.45:1; the temperature of the second heat activation treatment is 400-600℃, and the time is 2-5h;

[0055] (3) mixing deionized water and the catalyst powder obtained in step (2), stirring, then mixing the nano solidification liquid, and then performing second homogenization treatment for 0.5-4h to obtain a turbid liquid;

[0056] wherein the mass ratio of the nano solidification liquid to the catalyst powder is 0.02-1:1;

[0057] (4) immersing the catalyst substrate in the turbid liquid in step (3), and then sequentially performing purging treatment, drying, and third heat activation treatment to obtain the monolithic catalytic oxidation catalyst;

[0058] The pretreatment of the catalyst substrate comprises: soaking the catalyst substrate in an alkali solution with a concentration of 10-20wt% at a temperature of 30-40℃ for 30-60min, and then sequentially washing with deionized water and drying;

[0059] The third thermal activation treatment is performed at a temperature of 400-600℃ for 2-5h.

[0060] It is worth mentioning that the specific process parameters of the drying and homogenization treatment in the preparation method are not limited, as long as the drying of the intermediate product and the uniformity of the mixture can be achieved.

[0061] The numerical range of the present application includes not only the above-mentioned point values, but also any point values between the above-mentioned numerical ranges that are not mentioned. Due to the limited space and for the sake of simplicity, the present application does not list the specific point values included in the range.

[0062] Compared with the prior art, the present application has the following beneficial effects:

[0063] (1) The first component in the monolithic catalytic oxidation catalyst provided by the present application can adsorb and react with the sulfur-containing and halogen-containing components in the flue gas, avoiding the rapid poisoning and failure of the second active component, the carrier and other components, prolonging the service life of the catalyst and realizing stable operation;

[0064] (2) For high-humidity flue gas, the first active component in the catalyst can promote the adsorption, activation and dissociation of water molecules, improve the ability to remove VOCs / CO, overcome the problems of poor hydrophobic modification and poor uniformity of the surface of traditional catalysts, which leads to poor activity under humid conditions, and broaden the application of the catalyst under complex working conditions;

[0065] (3) By introducing a nano-solidification liquid during preparation, a physical solidification layer can be formed to inhibit the volatilization of the intermediate of the second active component formed during the reaction, further prolonging the service life of the catalyst. DETAILED DESCRIPTION

[0066] The technical solutions of the present application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0067] Example 1

[0068] The present embodiment provides a dual-loaded monolithic catalytic oxidation catalyst, which comprises a catalyst substrate and a catalyst coating coated on the surface of the catalyst substrate.

[0069] The catalyst coating comprises a catalyst carrier, and a first active component, a second active component and a nano-solidification agent supported on the catalyst carrier; the mass ratio of the first active component and the second active component is 20:1.

[0070] The preparation method of the double-loaded monolithic catalytic oxidation catalyst comprises the following steps:

[0071] (1) mixing 30 g of a catalyst carrier (HZSM-5 molecular sieve) and deionized water, uniformly ultrasonicating, then mixing 5 g of copper nitrate, and then sequentially performing stirring for 24 h, drying, first homogenization treatment for 1 h, and first thermal activation treatment, to obtain a multifunctional composite matrix;

[0072] The mass ratio of the copper nitrate to the catalyst carrier is 0.17:1; the temperature of the first thermal activation treatment is 500 DEG C, and the time is 3 h;

[0073] (2) mixing deionized water and 25 g of the multifunctional composite matrix obtained in step (1), uniformly ultrasonicating, then mixing 2.5 g of nitrosyl nitrate ruthenium, and then sequentially performing stirring, drying, and second thermal activation treatment, to obtain a catalyst powder;

[0074] The concentration of the nitrosyl nitrate ruthenium is 10 wt%; the mass ratio of the nitrosyl nitrate ruthenium to the multifunctional composite matrix is 0.01:1; the temperature of the second thermal activation treatment is 400 DEG C, and the time is 3 h;

[0075] (3) mixing deionized water and 15 g of the catalyst powder obtained in step (2), stirring, then mixing 10 g of acidic silica sol, and second homogenization treatment for 1 h, to obtain a turbid liquid;

[0076] The mass ratio of the nano-solidification liquid to the catalyst powder is 0.67:1;

[0077] (4) immersing a catalyst substrate in the turbid liquid in step (3), and then sequentially performing positive pressure purging treatment, drying, and third thermal activation treatment, to obtain the monolithic catalytic oxidation catalyst;

[0078] The pretreatment of the catalyst substrate comprises: immersing the catalyst substrate in a 10 wt% sodium hydroxide solution at a temperature of 40 DEG C for 300 min, and then sequentially performing deionized water washing and drying treatment; the catalyst substrate is a honeycomb cordierite;

[0079] The temperature of the third thermal activation treatment is 400 DEG C, and the time is 3 h.

[0080] Example 2

[0081] The embodiment provides a dual-load type monolithic catalytic oxidation catalyst, which comprises a catalyst substrate and a catalyst coating layer coated on the surface of the catalyst substrate;

[0082] The catalyst coating layer comprises a catalyst carrier, and a first active component, a second active component and a nano-solidification agent loaded on the catalyst carrier; the mass ratio of the first active component and the second active component is 40:1.

[0083] The preparation method of the dual-load type monolithic catalytic oxidation catalyst comprises the following steps:

[0084] (1) mixing 30 g of a catalyst carrier (HZSM-5 molecular sieve) and deionized water, uniformly ultrasonicating, then mixing 6 g of copper nitrate, and then sequentially performing stirring for 24 h, drying, first homogenization treatment for 2 h and first thermal activation treatment, to obtain a multifunctional composite matrix;

[0085] The mass ratio of the first active component precursor and the catalyst carrier is 0.2:1; the temperature of the first thermal activation treatment is 400 DEG C, and the time is 5 h.

[0086] (2) mixing deionized water and 25 g of the multifunctional composite matrix obtained in step (1), uniformly ultrasonicating, then mixing 1.25 g of ruthenium chloride, and then sequentially performing stirring, drying and second thermal activation treatment, to obtain a catalyst powder;

[0087] The concentration of the ruthenium chloride is 10 wt%; the mass ratio of the second active component precursor and the multifunctional composite matrix is 0.005:1; the temperature of the second thermal activation treatment is 400 DEG C, and the time is 5 h.

[0088] (3) mixing deionized water and 15 g of the catalyst powder obtained in step (2), stirring, then mixing 10 g of an acidic silica sol, and performing second homogenization treatment for 2 h to obtain a turbid liquid;

[0089] The mass ratio of the nano-solidification liquid and the catalyst powder is 0.67:1.

[0090] (4) immersing a catalyst substrate in the turbid liquid in step (3), and then sequentially performing purging treatment, drying and third thermal activation treatment, to obtain the monolithic catalytic oxidation catalyst.

[0091] The pretreatment of the catalyst substrate comprises the following steps: immersing the catalyst substrate in a 15 wt% sodium hydroxide solution at a temperature of 35 DEG C for 50 min, then sequentially performing deionized water washing and drying treatment; and the catalyst substrate is a honeycomb cordierite.

[0092] The third heat activation treatment has a temperature of 400 DEG C and a time of 5 h.

[0093] Embodiment 3

[0094] The embodiment provides a double-loaded monolithic catalytic oxidation catalyst, which comprises a catalyst substrate and a catalyst coating layer coated on the surface of the catalyst substrate.

[0095] The catalyst coating layer comprises a catalyst carrier, and a first active component, a second active component and a nano-solidification agent loaded on the catalyst carrier; the mass ratio of the first active component and the second active component is 20:1.

[0096] The preparation method of the double-loaded monolithic catalytic oxidation catalyst comprises the following steps:

[0097] (1) mixing 30 g of a catalyst carrier (SSZ-13 molecular sieve) and deionized water, uniformly ultrasonicating, then mixing 5 g of copper acetate, and then sequentially performing stirring for 18 h, drying, first homogenization treatment for 0.5 h and first heat activation treatment to obtain a multifunctional composite matrix;

[0098] The mass ratio of the first active component precursor and the catalyst carrier is 0.167:1; the first heat activation treatment has a temperature of 700 DEG C and a time of 2 h.

[0099] (2) mixing deionized water and 25 g of the multifunctional composite matrix obtained in step (1), uniformly ultrasonicating, then mixing 2.5 g of ruthenium chloride, and then sequentially performing stirring, drying and second heat activation treatment to obtain a catalyst powder;

[0100] The concentration of the ruthenium chloride is 10 wt%; the mass ratio of the ruthenium chloride and the multifunctional composite matrix is 0.01:1; the second heat activation treatment has a temperature of 600 DEG C and a time of 2 h.

[0101] (3) mixing deionized water and 15 g of the catalyst powder obtained in step (2), stirring, then mixing 10 g of acidic silica sol, and performing second homogenization treatment for 3 h to obtain a turbid liquid;

[0102] (4) immersing a catalyst substrate in the turbid liquid in step (3), and then sequentially performing positive pressure purging treatment, drying and third heat activation treatment to obtain the monolithic catalytic oxidation catalyst.

[0103] The pretreatment of the catalyst substrate comprises: immersing the catalyst substrate in a 10 wt% potassium hydroxide solution at a temperature of 40 DEG C for 60 min, and then sequentially performing deionized water washing and drying treatment.

[0104] The third heat activation treatment has a temperature of 600 DEG C and a time of 2 hours.

[0105] Embodiment 4

[0106] The embodiment provides a double-loaded monolithic catalytic oxidation catalyst, which comprises a catalyst substrate and a catalyst coating layer coated on the surface of the catalyst substrate.

[0107] The catalyst coating layer comprises a catalyst carrier, and a first active component, a second active component and a nano-solidification agent loaded on the catalyst carrier; the mass ratio of the first active component and the second active component is 20:1.

[0108] The embodiment provides a preparation method of the double-loaded monolithic catalytic oxidation catalyst.

[0109] (1) mixing 30 g of a catalyst carrier (titanium dioxide) and deionized water, uniformly ultrasonicating, then mixing 6 g of cerium nitrate, and then sequentially performing stirring for 18 hours, drying, first homogenization treatment for 0.5 hours and first heat activation treatment to obtain a multifunctional composite matrix;

[0110] The mass ratio of the first active component precursor and the catalyst carrier is 0.2:1; the first heat activation treatment has a temperature of 450 DEG C and a time of 3 hours.

[0111] (2) mixing deionized water and 25 g of the multifunctional composite matrix obtained in step (1), uniformly ultrasonicating, then mixing 2.5 g of platinum nitrate, and then sequentially performing stirring, drying and second heat activation treatment to obtain a catalyst powder;

[0112] The concentration of the platinum nitrate is 10 wt%; the mass ratio of the platinum nitrate and the multifunctional composite matrix is 0.01:1; the second heat activation treatment has a temperature of 400 DEG C and a time of 3 hours.

[0113] (3) mixing deionized water and 15 g of the catalyst powder obtained in step (2), stirring, then mixing 10 g of acid silicon sol, and performing second homogenization treatment for 3 hours to obtain a turbid liquid;

[0114] (4) immersing a catalyst substrate in the turbid liquid in step (3), and then sequentially performing positive pressure purging treatment, drying and third heat activation treatment to obtain the monolithic catalytic oxidation catalyst.

[0115] The pretreatment of the catalyst substrate comprises: immersing the catalyst substrate in a 10 wt% potassium hydroxide solution at a temperature of 40 DEG C for 60 minutes, and then sequentially performing deionized water washing and drying treatment.

[0116] The third heat activation treatment has a temperature of 400℃ and a time of 3h.

[0117] Example 5

[0118] This example provides a dual-support monolithic catalytic oxidation catalyst, and a preparation method thereof, which is different from that of Example 1 only in that:

[0119] This example adjusts the first homogenization treatment described in step (1) to ultrasonic treatment.

[0120] Example 6

[0121] This example provides a dual-support monolithic catalytic oxidation catalyst, and a preparation method thereof, which is different from that of Example 1 only in that:

[0122] This example adjusts the second homogenization treatment described in step (3) to mechanical stirring treatment.

[0123] Comparative Example 1

[0124] This comparative example provides a dual-support monolithic catalytic oxidation catalyst, which is different from that of Example 1 only in that:

[0125] This comparative example omits the loading of the first active component on the catalyst carrier.

[0126] The preparation method of the dual-support monolithic catalytic oxidation catalyst is different from that of Example 1 only in that this comparative example omits step (1), i.e., directly mixing the catalyst carrier and deionized water, and mixing the second active component precursor after ultrasonic treatment.

[0127] Comparative Example 2

[0128] This comparative example provides a dual-support monolithic catalytic oxidation catalyst, which is different from that of Example 1 only in that:

[0129] This comparative example omits the loading of the second active component on the catalyst carrier.

[0130] The preparation method of the dual-support monolithic catalytic oxidation catalyst is different from that of Example 1 only in that this comparative example omits step (2).

[0131] Comparative Example 3

[0132] This comparative example provides a dual-support monolithic catalytic oxidation catalyst, and a preparation method thereof, which is different from that of Example 4 only in that:

[0133] This comparative example omits the process of mixing the nano-solidification liquid in step (3).

[0134] Comparative Example 4

[0135] The present comparative example provides a dual-support monolithic catalytic oxidation catalyst, the preparation method of which is only different from that of Example 4 in that:

[0136] The present comparative example adjusts steps (1)-(2) to be: mixing the catalyst carrier and deionized water, uniformly ultrasonicating, then mixing the first active component precursor and the second active component precursor, and then sequentially performing stirring, drying, homogenization treatment and thermal activation treatment.

[0137] The catalysts provided by the above examples and comparative examples are used to detect the catalytic efficiency of the catalysts and the coating shedding rate, and the results are shown in Table 1.

[0138] The catalytic efficiency detection includes: purifying VOCs under water vapor contents of 0 and 5%, recording the initial efficiency of the catalyst and the catalytic efficiency after running for 50h;

[0139] Wherein, when the purification object of the catalyst is CO, the flue gas contains SO2;

[0140] The coating shedding rate is the ratio of the mass difference of the monolithic catalyst before and after ultrasonic drying to the mass of the catalyst coating.

[0141] Table 1

[0142]

[0143] In summary, the present application uses homogenization, thermal activation and other technologies to disperse the first active component on the surface of the pores inside and outside the catalyst carrier, forming a multifunctional composite matrix; during the catalytic reaction, the first active component can adsorb / react with the sulfur-containing and halogen-containing components in the flue gas to be treated, avoiding the rapid poisoning and failure of the second active component, the carrier, the substrate and other components, prolonging the service life of the catalyst and realizing stable operation of the catalyst. In addition, the first active component can also promote the adsorption, activation and dissociation of water molecules, improve the ability to remove VOCs / CO synergistically, overcome the problems of difficult hydrophobic modification and poor uniformity of the surface of traditional catalysts, which leads to poor activity under humid conditions, and broaden the application of the catalyst under complex working conditions.

[0144] The applicant declares that the above specific examples further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above examples are only specific embodiments of the present application and are not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A dual -supported monolithic catalytic oxidation catalyst characterized by, The monolithic catalytic oxidation catalyst comprises a catalyst substrate and a catalyst coating layer coated on the surface of the catalyst substrate; The catalyst coating layer comprises a catalyst carrier, and a first active component, a second active component and a nano-solidification agent supported on the catalyst carrier; the mass ratio of the first active component and the second active component is 0.5-40:

1.

2. The dual -load monolithic catalytic oxidation catalyst according to claim 1, characterized in that, The first active component comprises copper and / or cerium metal elements; Preferably, the second active component comprises any one or at least two combined metal elements of ruthenium, palladium or platinum; Preferably, the catalyst substrate comprises mullite or cordierite; Preferably, the catalyst carrier comprises any one or at least two combined of molecular sieve, titanium dioxide or cerium oxide.

3. The dual -load monolithic catalytic oxidation catalyst according to claim 1 or 2, characterized in that, The second active component accounts for 0.01-1.6% of the total mass of the catalyst; Preferably, the first active component accounts for 0.5-10% of the total mass of the catalyst.

4. A process for the preparation of a double supported monolithic catalytic oxidation catalyst according to any one of claims 1 to 3, characterized in that, The preparation method comprises the following steps: (1) mixing the catalyst carrier and deionized water, uniformly ultrasonic mixing, then mixing the first active component precursor, and then sequentially performing stirring, drying, first homogenization treatment and first thermal activation treatment to obtain a multifunctional composite matrix; (2) mixing the deionized water and the multifunctional composite matrix obtained in step (1), uniformly ultrasonic mixing, then mixing the second active component precursor, and then sequentially performing stirring, drying and second thermal activation treatment to obtain a catalyst powder; (3) mixing the deionized water and the catalyst powder obtained in step (2), stirring, then mixing the nano-solidification liquid, and then performing second homogenization treatment to obtain a turbid liquid; (4) immersing the catalyst substrate in the turbid liquid obtained in step (3), and then sequentially performing purging treatment, drying and third thermal activation treatment to obtain the monolithic catalytic oxidation catalyst.

5. The preparation method according to claim 4, characterized in that, The first active component precursor in step (1) comprises any one or at least two combined of copper nitrate, copper acetate or cerium nitrate; Preferably, the mass ratio of the first active component precursor to the catalyst carrier is 0.05-20:

1.

6. The production method according to claim 4 or 5, characterized by, The stirring time in step (1) is 12-24 h.

7. The method of any one of claims 4-6, wherein the method further comprises, The first homogenization treatment time in step (1) is 0.5-2 h.

8. The method of any one of claims 4-7, wherein, The first thermal activation treatment temperature in step (1) is 400-700℃; Preferably, the first thermal activation treatment time in step (1) is 2-5 h.

9. The method of any one of claims 4-8, wherein, The second active component precursor in step (2) comprises any one or at least two combined of ruthenium chloride, nitrosyl nitrate ruthenium, chloroplatinic acid, tetraammine platinum chloride, platinum nitrate, tetraammine platinum nitrate, palladium chloride, palladium nitrate or tetraammine palladium nitrate; Preferably, the mass ratio of the second active component precursor to the multifunctional composite matrix is 0.005-0.45:

1.

10. The method of any one of claims 4-9, wherein, The second thermal activation treatment temperature in step (2) is 400-600℃; Preferably, the second thermal activation treatment time in step (2) is 2-5 h.

11. The method of any one of claims 4-10, wherein, The nano-solidification liquid in step (3) comprises acidic or alkaline silica sol; Preferably, the mass ratio of the nano-solidification liquid to the catalyst powder is 0.02-1:

1.

12. The method of making according to any one of claims 4-11, wherein, The second homogenization treatment time in step (3) is 0.5-4 h.

13. The method of making according to any one of claims 4-12, wherein, The pre-treatment of the catalyst substrate before the submerging in step (4) is further included.

14. The method of claim 13, wherein, The pre-treatment includes soaking the catalyst substrate with an alkali solution, and then sequentially washing with deionized water and drying.

15. The method of claim 14, wherein, The alkali solution includes sodium hydroxide and / or potassium hydroxide. Preferably, the concentration of the alkali solution is 10-20 wt%.

16. The method of claim 14, wherein, The soaking treatment lasts for 30-60 min. Preferably, the soaking treatment is at a temperature of 30-40℃.

17. The method of making according to any one of claims 4-16, wherein, The third heat activation treatment in step (4) is at a temperature of 400-600℃. Preferably, the third heat activation treatment in step (4) lasts for 2-5 h.

18. The method of making according to any one of claims 4-17, wherein, The preparation method includes the following steps: (1) mixing the catalyst carrier and deionized water, uniformly ultrasonicating, then mixing the first active component precursor, and then sequentially stirring for 12-24 h, drying, first homogenization treatment for 0.5-2 h, and first heat activation treatment to obtain a multifunctional composite matrix; wherein the mass ratio of the first active component precursor to the catalyst carrier is 0.05-20:1; the first heat activation treatment is at a temperature of 400-700℃ and lasts for 2-5 h; (2) mixing the deionized water and the multifunctional composite matrix obtained in step (1), uniformly ultrasonicating, then mixing the second active component precursor, and then sequentially stirring, drying, and second heat activation treatment to obtain a catalyst powder; wherein the mass ratio of the second active component precursor to the multifunctional composite matrix is 0.005-0.45:1; the second heat activation treatment is at a temperature of 400-600℃ and lasts for 2-5 h; (3) mixing the deionized water and the catalyst powder obtained in step (2), stirring, then mixing a nano solidification liquid, and second homogenization treatment for 0.5-4 h to obtain a turbid liquid; wherein the mass ratio of the nano solidification liquid to the catalyst powder is 0.02-1:1; (4) submerging the catalyst substrate in the turbid liquid in step (3), and then sequentially performing purging treatment, drying, and third heat activation treatment to obtain the monolithic catalytic oxidation catalyst; wherein the pre-treatment of the catalyst substrate includes soaking the catalyst substrate with an alkali solution having a concentration of 10-20 wt% at a temperature of 30-40℃ for 30-60 min, and then sequentially washing with deionized water and drying; the third heat activation treatment is at a temperature of 400-600℃ and lasts for 2-5 h.

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