A catalytic oxidation catalyst, a method for preparing the same, and an application thereof

Abstract

This invention relates to the field of catalyst preparation technology, specifically disclosing a catalytic oxidation catalyst, its preparation method, and its application. The catalytic oxidation catalyst comprises: a support, wherein the support is an acid-treated, structured support; a coating attached to the support, wherein the coating contains a molecular sieve and optionally a metal oxide; and an active component dispersed in the coating, wherein the active component contains a noble metal and optionally an alloy metal; wherein the pore factor (HF) of the coating of the catalytic oxidation catalyst is 0.056–0.094. The catalytic oxidation catalyst of this invention exhibits high oxygen adsorption and activation capacity, high catalytic oxidation efficiency, high mechanical strength, and is suitable for high space velocity and large volume gas processing conditions; furthermore, the pore structure of the catalyst coating matrix is ​​tunable, providing strong quantitative adjustability and strong raw material adaptability.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, specifically to a catalytic oxidation catalyst, its preparation method and application, and more specifically, to a catalytic oxidation catalyst for removing non-methane gases such as CO and VOCs from exhaust gas, its preparation method, and its application in removing non-methane gases (i.e., carbon-based oxygen-containing molecular gases such as CO and VOCs) from exhaust gas through catalytic oxidation. Background Technology

[0002] In petrochemical production and processing, the generated tail gas contains non-methane gases such as CO and VOCs. Recovery costs for these tail gases are high. To meet emission requirements, methods such as adsorption, photocatalysis, low-temperature plasma conversion, and combustion are commonly used to remove non-methane gases. Among these, catalytic oxidation, which introduces a highly efficient catalyst to reduce the combustion temperature, has attracted widespread attention due to its simple process and high removal efficiency. Currently, the main treatment method for non-methane tail gas discharged from petrochemical plants is catalytic oxidation. Catalytic oxidation can completely oxidize oxygen-containing small molecules to form carbon dioxide. To meet the requirements of low pressure drop and high volume operation, current catalytic oxidation methods generally use monolithic catalysts supported on precious metals. However, the uneven distribution of coating pores, which cannot be controlled, results in poor catalyst shape selectivity, low selectivity, and poor activity.

[0003] Patent application CN102689911A describes a microwave alkaline treatment method for etching nanoscale ZSM-5 molecular sieves to prepare hierarchical ZSM-5 molecular sieve nanospheres with adjustable pore sizes between 30-150 nm. However, these methods for preparing hierarchical molecular sieves suffer from high costs and complex processes, hindering large-scale production.

[0004] Patent application CN107720771A discloses a method for preparing a macroporous-microporous molecular sieve catalyst TS-1. This method uses mesoporous silica microspheres as a hard template and silicon source, and controls the synthesis of a macroporous-microporous molecular sieve catalyst with tunable pore size by adjusting the reaction temperature, reaction time, and the amount of structure-directing agent. However, this molecular sieve preparation only introduces macropores and does not achieve tunable pore size, making it difficult to flexibly adapt to the increasingly changing raw material requirements.

[0005] Patent application CN111408342A discloses a high-silica composite molecular sieve adsorbent for VOCs removal and its preparation method. This method involves hydrothermal crystallization under microwave conditions, which modulates the surface hydrophobicity of the molecular sieve channels, but does not change the channel structure and size, thus failing to fully utilize its shape-selective catalytic ability.

[0006] Therefore, developing catalysts with tunable pores, high efficiency, low cost, environmental friendliness, and long-lasting strength has become a research hotspot and application trend for catalytic oxidation catalysts both domestically and internationally. Summary of the Invention

[0007] The purpose of this invention is to provide a catalytic oxidation catalyst, its preparation method, and its application for an efficient removal process of non-methane gases (such as CO and VOCs) from exhaust gases in chemical production processes. This invention achieves efficient construction of catalytic active sites on the catalyst surface by controlling the pore factor (HF) value of the catalyst coating, quantitatively regulating the dispersion of active metals and the exposure of the active phase, reducing the content of precious metal catalysts, increasing the adsorption capacity of CO, VOCs gases, and oxygen, promoting oxygen adsorption and activation, and thus improving the catalytic efficiency of the catalyst.

[0008] To achieve the above objectives, the present invention provides a catalytic oxidation catalyst, which comprises:

[0009] The carrier is an acid-treated, structured carrier;

[0010] A coating attached to the carrier, the coating comprising a molecular sieve and optionally a metal oxide; and

[0011] An active component dispersed in the coating, the active component containing a noble metal and optionally an alloy metal;

[0012] The coating pore factor HF of the catalytic oxidation catalyst is 0.056-0.094, and the coating pore factor HF is calculated using the following formula.

[0013] HF=(V micro / V total )×(S meso / S BET )

[0014] Among them, V micro Micropore volume, unit: cm 3 g -1 ;

[0015] V total Total pore volume, in cm. 3 g -1 ;

[0016] S meso Mesoporous specific surface area, in m³ 2 g -1 ;

[0017] S BET Total pore surface area, in m² 2 g-1 .

[0018] Preferably, the coating has a particle size of 50-500 nm, a mesopore size of 3-50 nm, and a specific surface area of ​​300-600 m². 2 / g, wherein the particle size of the active component is 1-8nm.

[0019] Preferably, the coating has a particle size of 80-300 nm, a mesopore size of 4-30 nm, and a specific surface area of ​​350-500 m². 2 / g, wherein the particle size of the active component is 2-6nm.

[0020] Preferably, the powder shedding rate of the coating is less than 1%, and more preferably 0.1-1%.

[0021] Preferably, the coating content is 1-10 parts by weight relative to 100 parts by weight of the carrier, and the active component content is 0.1-1 parts by weight.

[0022] Preferably, the regularized carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier and alumina honeycomb carrier.

[0023] Preferably, in the coating, the weight ratio of the molecular sieve to the metal oxide is 1:0.1-0.5.

[0024] Preferably, in the coating, the molecular sieve is at least one of ZSM-5 molecular sieve, TS-1 molecular sieve, and β molecular sieve.

[0025] Preferably, in the coating, the metal oxide is selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

[0026] Preferably, in the active component, the molar ratio of the noble metal to the alloy metal is 1:0.1-0.3.

[0027] Preferably, the precious metal is selected from at least one of ruthenium, rhodium, palladium, osmium, iridium and platinum, and more preferably a combination of platinum and palladium.

[0028] Preferably, the alloy metal is at least one of Fe, La and Ce, and more preferably a combination of Fe, La and Ce.

[0029] A second aspect of the present invention provides a method for preparing a catalytic oxidation catalyst, the method comprising the following steps:

[0030] (1) Treat the structured carrier with acid;

[0031] (2) Mix the alcohol solution of sodium aluminate with an aqueous solution containing microporous template agent and silicon source, age it, remove the alcohol, and then mix the resulting gel with molecular sieve seed crystals and mesoporous template agent.

[0032] (3) The mixed solution obtained in step (2) is mixed with metal oxide and ball-milled to obtain a coating slurry;

[0033] (4) The coating slurry is mixed with a mixed solution containing a noble metal precursor and a structural aid. The resulting mixed slurry is added to an acid-treated structured carrier, and then the carrier is purged, dried, calcined and reduced in sequence.

[0034] In step (2), the mesoporous template agent is an alkyltrimethylammonium halide, wherein the alkyl group has C atoms. x The halogen is 8-18, and the halogen is fluorine, chlorine, or bromine;

[0035] According to C x The functional relationship between HF and HF is HF = 0.0032C. x +0.0334±0.003, determined by the number of carbon atoms (C) of the alkyl group in the alkyltrimethylammonium halide chosen as the mesoporous template agent. x The pore factor HF of the coating of the prepared catalytic oxidation catalyst is adjusted.

[0036] Preferably, in step (1), the acid treatment process includes: reflux treatment of the regularized carrier with an acidic solution, followed by washing until neutral and drying.

[0037] Preferably, the concentration of the acidic solution is 1-3 mol / L.

[0038] Preferably, the acid in the acidic solution is at least one of nitric acid, sulfuric acid, and hydrochloric acid.

[0039] Preferably, the reflux treatment conditions include: a temperature of 70-90°C and a time of 12-36 hours.

[0040] Preferably, the regularized carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier and alumina honeycomb carrier.

[0041] Preferably, in step (2), the specific process of mixing the alcoholic solution of sodium aluminate with the aqueous solution containing the microporous template agent and the silicon source is as follows: the alcoholic solution of sodium aluminate is added to the aqueous solution containing the microporous template agent and the silicon source at a rate of 0.005-0.015 mL / min, and the mixture is stirred for 2-5 hours.

[0042] Preferably, the microporous template agent is selected from at least one of tetrapropylammonium hydroxide, tetrapropylammonium bromide, and tetraethylammonium hydroxide.

[0043] Preferably, the silicon source is selected from at least one of silicates, silicic acid, silica hydrogels, and tetraethyl orthosilicate.

[0044] Preferably, the molecular sieve seed crystals are selected from at least one of ZSM-5 molecular sieve seed crystals, TS-1 molecular sieve seed crystals, and β molecular sieve seed crystals.

[0045] Preferably, the concentration of the mesoporous template agent is 0.5-5 mol / L, and more preferably 1-3 mol / L.

[0046] Preferably, the mesoporous template agent is selected from octaalkyltrimethylammonium bromide, decaalkyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide and hexadecyltrimethylammonium bromide.

[0047] Preferably, in step (3), the metal oxide is selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

[0048] Preferably, in step (4), the pH value of the mixed solution containing the noble metal precursor and the structural aid is 9-12.

[0049] Preferably, the noble metal precursor is selected from at least one of chloroplatinic acid, 2-hydroxyethylamine salt of platinum(IV) hydroxyhydroxide, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate, and palladium acetate.

[0050] Preferably, the structural additive is selected from at least one of ferric nitrate, cerium nitrate, lanthanum nitrate, lanthanum sulfate, lanthanum chloride, cerium sulfate, and cerium trioxide.

[0051] Preferably, in step (4), the purging process is performed by purging with a 1.5-2.5MPa air knife.

[0052] Preferably, the roasting conditions include: a temperature of 200-300℃ and a time of 4-10 hours.

[0053] Preferably, during the reduction process, the reducing atmosphere is H2, CO, a combination of H2 and CO, a mixed atmosphere with different hydrogen concentrations, and a mixed atmosphere with different CO concentrations.

[0054] Preferably, the reduction conditions include: a catalyst heating rate of 2-20℃ / min, a reduction temperature of 300-450℃, and a reduction time of 1-10h.

[0055] A third aspect of the present invention provides a catalytic oxidation catalyst prepared by the above method.

[0056] The fourth aspect of the present invention provides the application of the above-mentioned catalytic oxidation catalyst in removing carbon-based oxygen-containing molecular gases from exhaust gases.

[0057] According to the technical solution of the present invention, in the preparation process of the catalyst, a coating slurry containing molecular sieves is attached after acid treatment of the structured support. The molecular sieves in the coating slurry can react with the exposed hydroxyl groups on the surface of the acid-treated structured support, forming chemical bonds between the coating and the structured support. Therefore, the coating has high adhesion and extremely low powdering rate. Furthermore, in the technical solution of the present invention, the carbon number of the alkyl group in the alkyltrimethylammonium halide used as a mesoporous template agent is selected to be C x The coating pore factor HF of the prepared catalytic oxidation catalyst is adjusted to control the coating structure of the catalytic oxidation catalyst, promote the dispersion of active noble metals and the exposure of active phase, efficiently construct catalytic active sites on the catalyst surface, reduce the content of noble metal catalyst, increase the adsorption capacity of carbon-based oxygen-containing molecular gas and oxygen, promote oxygen adsorption and activation, and thus improve the catalytic efficiency of the catalyst.

[0058] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0059] (1) Compared with other catalytic oxidation catalysts, the catalytic oxidation catalyst of the present invention has higher oxygen adsorption and activation capabilities and higher catalytic oxidation efficiency;

[0060] (2) Compared with other catalytic oxidation catalysts, the catalytic oxidation catalyst of the present invention has high mechanical strength and is suitable for high space velocity and large volume gas processing conditions;

[0061] (3) Compared with other catalytic oxidation catalysts, the coating matrix pore structure of the catalytic oxidation catalyst of the present invention is adjustable, which has the advantages of strong quantitative adjustment and strong raw material adaptability.

[0062] (4) Compared with other catalytic oxidation catalysts, the catalytic oxidation catalyst of the present invention has a low content of precious metals, which can greatly reduce operating costs. Detailed Implementation

[0063] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0064] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0065] In this invention, unless otherwise specified, the gas concentration "%" refers to "volume %"; "space velocity" refers to "volume space velocity"; and "pressure" refers to absolute pressure.

[0066] In this invention, "micropore" refers to a pore with a diameter of less than 2 nm, "mesopore" refers to a pore with a diameter between 2 and 50 nm, and "macropore" refers to a pore with a diameter of more than 50 nm.

[0067] The catalytic oxidation catalyst of the present invention comprises:

[0068] The carrier is an acid-treated, structured carrier;

[0069] A coating attached to the carrier, the coating comprising a molecular sieve and optionally a metal oxide; and

[0070] An active component dispersed in the coating, the active component containing a noble metal and optionally an alloy metal.

[0071] In the catalytic oxidation catalyst of the present invention, the coating pore factor HF of the catalytic oxidation catalyst is 0.056-0.094, and the coating pore factor HF is calculated by the following formula.

[0072] HF=(V micro / V total )×(S meso / S BET )

[0073] Among them, V micro Micropore volume, unit: cm 3 g -1 ;

[0074] V total Total pore volume, in cm. 3 g -1 ;

[0075] S meso Mesoporous specific surface area, in m³ 2 g -1 ;

[0076] S BET Total pore surface area, in m²2 g -1 .

[0077] In this invention, V micro V total S meso and S BET The molecular sieve was detected by physical adsorption. Specifically, the physical adsorption experiment was conducted using an ASAP2020 analyzer from Micron Technology, USA. The specific surface area and pore structure information of the molecular sieve were obtained by analyzing the N2-physical adsorption-desorption isotherm (N2-BET). The specific surface area of ​​the sample was calculated using the BET method, and the average pore size, pore volume, and pore size distribution were obtained by calculating the desorption isotherm using the BJH method. Before adsorption, the sample was evacuated at 300℃ for 6 hours.

[0078] According to the catalytic oxidation catalyst of the present invention, the pore factor HF of the coating is controlled within the range of 0.056-0.094, so that the catalytic oxidation catalyst has good stability and high conversion rate when used to remove carbon-based oxygen-containing molecular gases from exhaust gas.

[0079] In the catalytic oxidation catalyst of the present invention, the particle size of the coating can be 50-500 nm, preferably 80-300 nm, and more preferably 80-150 nm.

[0080] In the catalytic oxidation catalyst of the present invention, the mesoporous channel size of the coating can be in the range of 3-50 nm, preferably 4-30 nm.

[0081] In the catalytic oxidation catalyst of the present invention, the specific surface area of ​​the coating can be 300-600 m². 2 / g, preferably 350-500m 2 / g.

[0082] In the catalytic oxidation catalyst of the present invention, the active component is sufficiently dispersed in the coating, and the particle size of the active component is small. Specifically, the particle size of the active component is 1-8 nm, preferably 2-6 nm.

[0083] In the catalytic oxidation catalyst of this invention, the molecular sieve in the coating has a strong bond with the acid-treated structured support, resulting in a low powder shedding rate. Specifically, the powder shedding rate of the coating is less than 1%, preferably 0.1-1%, and more preferably 0.1-0.5%. In this invention, the powder shedding rate is detected by ultrasonic vibration method, with the detection conditions including: ultrasonic frequency 45kHz, ultrasonic power 130W, and processing time 60min.

[0084] In the catalytic oxidation catalyst of the present invention, the content of the coating relative to 100 parts by weight of the support can be 1-10 parts by weight, specifically, for example, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, or 10 parts by weight; the content of the active component can be 0.1-1 part by weight, specifically, for example, 0.1 part by weight, 0.2 part by weight, 0.3 part by weight, 0.4 part by weight, 0.5 part by weight, 0.6 part by weight, 0.7 part by weight, 0.8 part by weight, 0.9 part by weight, or 1 part by weight.

[0085] In the catalytic oxidation catalyst of the present invention, the structured support may be selected from at least one of cordierite honeycomb support, mullite honeycomb support, diamond honeycomb support, corundum honeycomb support, zirconium corundum honeycomb support, quartz honeycomb support, nepheline honeycomb support, feldspar honeycomb support and alumina honeycomb support, with cordierite honeycomb support being the most preferred.

[0086] In the catalytic oxidation catalyst of the present invention, the metal oxide is an optional component included in the coating. In a preferred embodiment, the coating contains a molecular sieve and a metal oxide. When the coating contains a metal oxide, the weight ratio of the molecular sieve to the metal oxide can be 1:0.1-0.5, preferably 1:0.2-0.4.

[0087] In the catalytic oxidation catalyst of the present invention, the molecular sieve in the coating is selected from at least one of ZSM-5 molecular sieve, TS-1 molecular sieve and β molecular sieve, with ZSM-5 molecular sieve being the most preferred.

[0088] In the catalytic oxidation catalyst of the present invention, the metal oxide in the coating may be selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

[0089] In the catalytic oxidation catalyst of the present invention, the alloy metal is an optional component included in the active component. In a preferred embodiment, the active component contains a noble metal and an alloy metal. In this preferred embodiment, the active component exists in the form of a noble metal element, an alloy, or a noble metal oxide. In the active component, the molar ratio of the noble metal to the alloy metal can be 1:0.1-0.3, preferably 1:0.15-0.2.

[0090] In the catalytic oxidation catalyst of the present invention, the noble metal in the active component may be selected from at least one of ruthenium, rhodium, palladium, osmium, iridium and platinum, preferably a combination of platinum and palladium. When the noble metal is a combination of platinum and palladium, the molar ratio of platinum to palladium may be 1:0.5-2, and most preferably 1:1.

[0091] In the catalytic oxidation catalyst of the present invention, the alloy metal in the active component can be at least one of Fe, La, and Ce, preferably a combination of Fe, La, and Ce. When the alloy metal is a combination of Fe, La, and Ce, the molar ratio of Fe, La, and Ce can be 1:0.5-2:0.5-2, and most preferably 1:1:1.

[0092] According to some embodiments of the present invention, the catalytic oxidation catalyst comprises:

[0093] The carrier is an acid-treated, structured carrier;

[0094] A coating, which is a molecular sieve, is attached to the carrier; and

[0095] The active component is dispersed in the coating, and the metal in the active component is a noble metal;

[0096] The pore factor (HF) of the coating of the catalytic oxidation catalyst is 0.056-0.094; the particle size of the coating is 50-500 nm, the mesopore size is 3-50 nm, and the specific surface area is 300-600 m². 2 / g, the particle size of the active component is 1-8nm, and the powder shedding rate of the coating is less than 1%; relative to 100 parts by weight of the carrier, the content of the coating is 1-10 parts by weight, and the content of the active component is 0.1-1 parts by weight;

[0097] The regularized carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier and alumina honeycomb carrier; the precious metal is selected from at least one of ruthenium, rhodium, palladium, osmium, iridium and platinum.

[0098] According to other embodiments of the present invention, the catalytic oxidation catalyst comprises:

[0099] The carrier is an acid-treated, structured carrier;

[0100] A coating attached to the carrier, the coating being a molecular sieve and a metal oxide; and

[0101] The active components dispersed in the coating, wherein the metals in the active components are noble metals and alloy metals;

[0102] The pore factor (HF) of the coating of the catalytic oxidation catalyst is 0.056-0.094; the particle size of the coating is 50-500 nm, the mesopore size is 3-50 nm, and the specific surface area is 300-600 m². 2 / g, the particle size of the active component is 1-8nm, and the powder shedding rate of the coating is less than 1%; relative to 100 parts by weight of the carrier, the content of the coating is 1-10 parts by weight, and the content of the active component is 0.1-1 parts by weight;

[0103] The regularized carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier, and alumina honeycomb carrier; the precious metal is selected from at least one of ruthenium, rhodium, palladium, osmium, iridium, and platinum; the metal oxide is selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO, and ZrO2; and the alloy metal is at least one of Fe, La, and Ce.

[0104] According to other embodiments of the present invention, the catalytic oxidation catalyst comprises:

[0105] The carrier is an acid-treated, structured carrier;

[0106] A coating attached to the carrier, the coating being a molecular sieve and a metal oxide; and

[0107] The active components dispersed in the coating, wherein the metals in the active components are noble metals and alloy metals;

[0108] The pore factor (HF) of the coating of the catalytic oxidation catalyst is 0.056-0.094; the particle size of the coating is 80-300 nm, the mesopore size is 4-30 nm, and the specific surface area is 350-500 m². 2 / g, the particle size of the active component is 2-6nm, and the powder shedding rate of the coating is 0.1-1%; relative to 100 parts by weight of the carrier, the content of the coating is 1-10 parts by weight, and the content of the active component is 0.1-1 parts by weight;

[0109] The regularized carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier, and alumina honeycomb carrier; the noble metal is a combination of platinum and palladium; the metal oxide is selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO, and ZrO2; and the alloy metal is a combination of Fe, La, and Ce.

[0110] According to other embodiments of the present invention, the catalytic oxidation catalyst comprises:

[0111] The carrier is an acid-treated, structured carrier;

[0112] The coating attached to the carrier is a molecular sieve and a metal oxide, wherein the weight ratio of the molecular sieve to the metal oxide is 1:0.1-0.5; and an active component dispersed in the coating, wherein the metal in the active component is a noble metal and an alloy metal, wherein the molar ratio of the noble metal to the alloy metal is 1:0.1-0.3.

[0113] The pore factor (HF) of the coating of the catalytic oxidation catalyst is 0.056-0.094; the particle size of the coating is 80-300 nm, the mesopore size is 4-30 nm, and the specific surface area is 350-500 m². 2 / g, the particle size of the active component is 2-6nm, and the powder shedding rate of the coating is 0.1-1%; relative to 100 parts by weight of the carrier, the content of the coating is 1-10 parts by weight, and the content of the active component is 0.1-1 parts by weight;

[0114] The regularized carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier, and alumina honeycomb carrier; the noble metal is a combination of platinum and palladium, and the molar ratio of platinum to palladium can be 1:0.5-2; the metal oxide is selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO, and ZrO2; the alloy metal is a combination of Fe, La, and Ce, and the molar ratio of Fe, La, and Ce can be 1:0.5-2:0.5-2.

[0115] The preparation method of the catalytic oxidation catalyst of the present invention includes the following steps:

[0116] (1) Treat the structured carrier with acid;

[0117] (2) Mix the alcohol solution of sodium aluminate with an aqueous solution containing microporous template agent and silicon source, age it, remove the alcohol, and then mix the resulting gel with molecular sieve seed crystals and mesoporous template agent.

[0118] (3) The mixed solution obtained in step (2) is mixed with metal oxide and ball-milled to obtain a coating slurry;

[0119] (4) The coating slurry is mixed with a mixed solution containing a noble metal precursor and a structural aid. The resulting mixed slurry is added to an acid-treated structured carrier, and then the carrier is purged, dried, calcined and reduced in sequence.

[0120] In step (2), the mesoporous template agent is an alkyltrimethylammonium halide, wherein the alkyl group has C atoms. x The halogen is 8-18, and the halogen is fluorine, chlorine, or bromine;

[0121] According to C x The functional relationship between HF and HF is HF = 0.0032C. x +0.0334±0.003, determined by the number of carbon atoms (C) of the alkyl group in the alkyltrimethylammonium halide chosen as the mesoporous template agent. x The pore factor HF of the coating of the prepared catalytic oxidation catalyst is adjusted.

[0122] In step (1), the acid treatment process can remove impurities contained in the structured support and form a bare hydroxyl surface. The acid treatment process may include: refluxing the structured support with an acidic solution, then washing it until neutral and drying it.

[0123] Specifically, the concentration of the acidic solution can be 1-3 mol / L, preferably 1.5-2.5 mol / L, and most preferably 2 mol / L.

[0124] Specifically, the acid in the acidic solution can be an inorganic strong acid, preferably at least one of nitric acid, sulfuric acid and hydrochloric acid, with nitric acid being the most preferred.

[0125] Specifically, the conditions for the reflux treatment may include: a temperature of 70-90°C, preferably 80°C; and a time of 12-36 hours, preferably 24 hours.

[0126] In the method described in this invention, the regularized carrier may be selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier and alumina honeycomb carrier, preferably cordierite honeycomb carrier.

[0127] In step (2), the specific process of mixing the alcoholic solution of sodium aluminate with the aqueous solution containing the microporous template agent and the silicon source is as follows: the alcoholic solution of sodium aluminate is added to the aqueous solution containing the microporous template agent and the silicon source at a rate of 0.005-0.015 mL / min, and the mixture is stirred for 2-5 hours.

[0128] In this invention, the alcohol solvent used in the sodium aluminate alcohol solution can be at least one of isopropanol, ethanol and n-propanol.

[0129] In this invention, the concentration of the sodium aluminate alcohol solution can be 5-15% by weight.

[0130] In this invention, the silicon source can be selected from water-soluble or water-soluble silicon-containing compounds, typically referring to silicon dioxide (SiO2) sources. In specific embodiments, the silicon source includes, but is not limited to, at least one of silicates, silicic acid, silica hydrogels, and tetraethyl orthosilicate, preferably tetraethyl orthosilicate.

[0131] In this invention, the microporous template agent may be selected from at least one of tetrapropylammonium hydroxide, tetrapropylammonium bromide, and tetraethylammonium hydroxide.

[0132] In the method described in this invention, the concentration of the mesoporous template agent can be 0.5-5 mol / L, preferably 1-3 mol / L.

[0133] In this invention, the mesoporous template agent may be selected from octaalkyltrimethylammonium bromide, decaalkyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide and hexadecyltrimethylammonium bromide.

[0134] In step (2), the aging process can be carried out at room temperature for 2-5 hours.

[0135] In step (2), the alcohol removal process specifically involves heating the aged mixed solution to 85-95°C at a rate of 1-20°C / min (preferably 5-17°C / min) and removing alcohol at 85-95°C for 10-15 hours.

[0136] In step (2), the process of mixing the gel liquid with the molecular sieve seed crystals and the mesoporous template agent is carried out under stirring. The mixing conditions may include: a temperature of 35-45°C and a time of 0.5-2 hours.

[0137] In step (2), the molecular sieve seed crystal can be selected from at least one of ZSM-5 molecular sieve seed crystal, TS-1 molecular sieve seed crystal and β molecular sieve seed crystal, preferably ZSM-5 molecular sieve seed crystal.

[0138] In this invention, the metal oxide may be selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

[0139] In step (3), the mixing and milling time can be 1-5 hours, preferably 2-3 hours.

[0140] In step (4), the process of mixing the coating slurry with a mixed solution containing a noble metal precursor and a structural additive is carried out under stirring. The mixing conditions may include: a temperature of 15-40°C, preferably 25°C; and a time of 1-4 hours, preferably 3 hours.

[0141] In step (4), the pH value of the mixed solution containing the noble metal precursor and the structural aid is 9-12. Specifically, the pH value of the mixed solution can be, for example, 9, 10, 11 or 12.

[0142] In this invention, the noble metal in the noble metal precursor is at least one selected from silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum, preferably a combination of platinum and palladium. In a specific embodiment, the noble metal precursor is at least one selected from chloroplatinic acid, 2-hydroxyethylamine hexahydroxide platinum(IV) acid, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate, and palladium acetate.

[0143] In step (4), the structural additive is added to form an alloy with the noble metal. In a specific embodiment, the structural additive is selected from at least one of ferric nitrate, cerium nitrate, lanthanum nitrate, lanthanum sulfate, lanthanum chloride, cerium sulfate, and cerium trioxide.

[0144] In step (4), the purging process can be carried out by purging with a 1.5-2.5MPa air knife.

[0145] In step (4), the drying process can be carried out in a drying oven. Specifically, the temperature of the drying oven can be 80-120℃, preferably 100℃; the drying time can be 5-24 hours, preferably 12 hours.

[0146] In step (4), the calcination conditions may include: a temperature of 200-300℃ and a time of 4-10 hours.

[0147] In step (4), during the reduction process, the reducing atmosphere can be H2, CO, a combination of H2 and CO, a mixed atmosphere with different hydrogen concentrations, or a mixed atmosphere with different CO concentrations. In a specific embodiment, the reducing atmosphere is a mixed atmosphere with different H2 concentrations and / or a mixed atmosphere with different CO concentrations. By adjusting the reducing atmosphere, efficient control of oxygen vacancy formation on the catalyst surface can be achieved. Specifically, the reducing atmosphere can be, for example, 5% H2 (diluted with N2), 10% H2 (diluted with N2), 15% H2 (diluted with N2), or 5% CO (diluted with N2).

[0148] In step (4), the reduction conditions may include: a catalyst heating rate of 2-20℃ / min, a reduction temperature of 300-450℃, and a reduction time of 1-10h.

[0149] In the method described in this invention, the amounts of various reaction raw materials used in steps (1) to (4) are such that, in the prepared catalytic oxidation catalyst, the content of the coating is 1-10 parts by weight relative to 100 parts by weight of the support, and the content of the active component is 0.1-1 parts by weight.

[0150] According to some embodiments of the present invention, the preparation method of the catalytic oxidation catalyst includes the following steps:

[0151] (1) The structured carrier is refluxed with an acidic solution, then washed until neutral and dried to obtain an acid-treated structured carrier;

[0152] (2) Add the sodium aluminate alcohol solution to an aqueous solution containing microporous template agent and silicon source at a rate of 0.005-0.015 mL / min, stir and mix for 2-5 hours, age, remove alcohol, and then mix the resulting gel solution with molecular sieve seed crystals and mesoporous template agent to obtain a mixed solution.

[0153] (3) The mixed solution is mixed with metal oxide and ball-milled to obtain a coating slurry;

[0154] (4) The coating slurry is mixed with a mixed solution containing a noble metal precursor and a structural additive. The resulting mixed slurry is added to the acid-treated structured carrier and purged with a 1.5-2.5 MPa air knife. Then, the carrier is dried, calcined and reduced in sequence.

[0155] In step (2), the mesoporous template agent is an alkyltrimethylammonium halide, wherein the alkyl group has C atoms. x The halogen is 8-18, and the halogen is fluorine, chlorine, or bromine;

[0156] According to C x The functional relationship between HF and HF is HF = 0.0032C.x +0.0334±0.003, determined by the number of carbon atoms (C) of the alkyl group in the alkyltrimethylammonium halide chosen as the mesoporous template agent. x The pore factor HF of the coating of the prepared catalytic oxidation catalyst is adjusted.

[0157] According to other embodiments of the present invention, the method for preparing the catalytic oxidation catalyst includes the following steps:

[0158] (1) The structured carrier is refluxed with an acidic solution, then washed until neutral and dried to obtain an acid-treated structured carrier;

[0159] (2) Add the sodium aluminate alcohol solution to an aqueous solution containing a microporous template agent and a silicon source at a rate of 0.005-0.015 mL / min, stir and mix for 2-5 hours, age, remove alcohol, and then mix the resulting gel with molecular sieve seeds and mesoporous template agent to obtain a mixed solution, wherein the concentration of the sodium aluminate alcohol solution is 5-15% by weight, and the concentration of the mesoporous template agent is in the range of 0.5-5 mol / L;

[0160] (3) The mixed solution is mixed with metal oxide and ball-milled to obtain a coating slurry;

[0161] (4) The coating slurry is mixed with a mixed solution containing a noble metal precursor and a structural aid. The resulting mixed slurry is added to the acid-treated structured support and purged with a 1.5-2.5 MPa air knife. Then, drying, calcination, and reduction are performed sequentially. The pH value of the mixed solution containing the noble metal precursor and the structural aid is 9-12. The noble metal in the noble metal precursor is at least one of silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. The metal in the structural aid is at least one of Fe, La, and Ce. The calcination conditions include a temperature of 200-300℃ and a time of 4-10 hours. The reduction atmosphere in the reduction process is H2, CO, a combination of H2 and CO, a mixed atmosphere with different hydrogen concentrations, and a mixed atmosphere with different CO concentrations. The reduction conditions include a catalyst heating rate of 2-20℃ / min, a reduction temperature of 300-450℃, and a reduction time of 1-10 hours.

[0162] In step (2), the mesoporous template agent is an alkyltrimethylammonium halide, wherein the alkyl group has C atoms. x The halogen is 8-18, and the halogen is fluorine, chlorine, or bromine;

[0163] According to C x The functional relationship between HF and HF is HF = 0.0032C. x+0.0334±0.003, determined by the number of carbon atoms (C) of the alkyl group in the alkyltrimethylammonium halide chosen as the mesoporous template agent. x The pore factor HF of the coating of the prepared catalytic oxidation catalyst is adjusted.

[0164] According to other embodiments of the present invention, the method for preparing the catalytic oxidation catalyst includes the following steps:

[0165] (1) The structured carrier is refluxed with an acidic solution, then washed until neutral and dried to obtain an acid-treated structured carrier. The concentration of the acidic solution is 1-3 mol / L, and the acid used is at least one of nitric acid, sulfuric acid and hydrochloric acid. The structured carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier and alumina honeycomb carrier.

[0166] (2) Add the sodium aluminate alcohol solution to an aqueous solution containing a microporous template agent and a silicon source at a rate of 0.005-0.015 mL / min, stir and mix for 2-5 hours, age at room temperature for 2-5 hours, raise the temperature of the aged mixed solution to 85-95℃ at a rate of 1-20℃ / min, remove alcohol at 85-95℃ for 10-15 hours, and then mix the obtained gel with molecular sieve seeds and mesoporous template agent to obtain a mixed solution, wherein the concentration of the sodium aluminate alcohol solution is 5-15% by weight, and the concentration of the mesoporous template agent is in the range of 0.5-5 mol / L;

[0167] (3) The mixed solution is mixed with a metal oxide and ball-milled to obtain a coating slurry, wherein the metal oxide is at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2;

[0168] (4) The coating slurry is mixed with a mixed solution containing a noble metal precursor and a structural aid. The resulting mixed slurry is added to the acid-treated structured support and purged with a 1.5-2.5 MPa air knife. Then, drying, calcination, and reduction are performed sequentially. The pH value of the mixed solution containing the noble metal precursor and the structural aid is 9-12. The noble metal in the noble metal precursor is at least one of silver, ruthenium, rhodium, palladium, osmium, iridium, and platinum. The metal in the structural aid is at least one of Fe, La, and Ce. The calcination conditions include a temperature of 200-300℃ and a time of 4-10 hours. The reduction atmosphere in the reduction process is H2, CO, a combination of H2 and CO, a mixed atmosphere with different hydrogen concentrations, and a mixed atmosphere with different CO concentrations. The reduction conditions include a catalyst heating rate of 2-20℃ / min, a reduction temperature of 300-450℃, and a reduction time of 1-10 hours.

[0169] In step (2), the mesoporous template agent is an alkyltrimethylammonium halide, wherein the alkyl group has C atoms. x The halogen is 8-18, and the halogen is fluorine, chlorine, or bromine;

[0170] According to C x The functional relationship between HF and HF is HF = 0.0032C. x +0.0334±0.003, determined by the number of carbon atoms (C) of the alkyl group in the alkyltrimethylammonium halide chosen as the mesoporous template agent. x The pore factor HF of the coating of the prepared catalytic oxidation catalyst is adjusted.

[0171] According to other embodiments of the present invention, the method for preparing the catalytic oxidation catalyst includes the following steps:

[0172] (1) The structured carrier is subjected to reflux treatment with an acidic solution, then washed until neutral and dried to obtain an acid-treated structured carrier. The reflux treatment conditions include: a temperature of 70-90℃ and a time of 12-36 hours; the concentration of the acidic solution is 1.5-2.5 mol / L; the acid used is nitric acid; and the structured carrier is a cordierite honeycomb carrier.

[0173] (2) Add an alcoholic solution of sodium aluminate with a concentration of 5-15% by weight to an aqueous solution containing a microporous template agent and a silicon source at a rate of 0.005-0.015 mL / min, stir and mix for 2-5 hours, age at room temperature for 2-5 hours, raise the temperature of the aged mixed solution to 85-95℃ at a rate of 1-20℃ / min, remove alcohol at 85-95℃ for 10-15 hours, and then stir and mix the obtained gel with molecular sieve seed crystals and mesoporous template agent to obtain a mixed solution, wherein the concentration of the mesoporous template agent is 0.5-5 mol / L, and the molecular sieve seed crystal is at least one of ZSM-5 molecular sieve seed crystal, TS-1 molecular sieve seed crystal and β molecular sieve seed crystal;

[0174] (3) The mixed solution is mixed with a metal oxide and ball-milled to obtain a coating slurry, wherein the metal oxide is at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2;

[0175] (4) The coating slurry is mixed with a mixed solution containing a noble metal precursor and a structural aid at 15-40°C for 1-4 hours under stirring. The resulting mixed slurry is then dropwise added to the acid-treated structured carrier and purged with a 1.5-2.5 MPa air knife. The mixture is then dried, calcined, and reduced sequentially. The pH of the mixed solution containing the noble metal precursor and structural aid is 9-12. The noble metal precursor is a platinum precursor (such as chloroplatinic acid, 2-hydroxyethylamine salt of platinum(IV) hydroxyapatite, platinum chloride, or platinum nitrate). The catalyst is prepared by calcining a catalyst with a catalyst heating rate of 2-20℃ / min, a reduction temperature of 300-450℃, and a reduction time of 1-10h. The catalyst is prepared by calcining a catalyst with a catalyst heating rate of 2-20℃ / min, a reduction temperature of 300-450℃, and a reduction time of 1-10h. The structural additives are ferric nitrate, cerium nitrate, and lanthanum nitrate.

[0176] In step (2), the mesoporous template agent is an alkyltrimethylammonium halide, wherein the alkyl group has C atoms. x The halogen is 8-18, and the halogen is fluorine, chlorine, or bromine;

[0177] According to C x The functional relationship between HF and HF is HF = 0.0032C. x +0.0334±0.003, determined by the number of carbon atoms (C) of the alkyl group in the alkyltrimethylammonium halide chosen as the mesoporous template agent. x The pore factor HF of the coating of the prepared catalytic oxidation catalyst is adjusted.

[0178] The present invention also provides a catalytic oxidation catalyst prepared by the above method. In this catalytic oxidation catalyst, the molecular sieve in the coating reacts with the exposed hydroxyl groups on the surface of the acid-treated regular support to form chemical bonds, resulting in high coating strength and extremely low powder shedding rate; moreover, the active noble metal is uniformly dispersed and the particle size of the active components is small; the pore structure of the coating matrix is ​​adjustable, which has the advantages of strong quantitative adjustment and strong raw material adaptability.

[0179] The present invention also provides the application of the above-mentioned catalytic oxidation catalyst in removing carbon-based oxygen-containing molecular gases from exhaust gases.

[0180] The following examples further illustrate the catalytic oxidation catalyst, its preparation method, and its application according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0181] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0182] Example 1

[0183] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0184] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 3.5g of commercially available ZSM-5 seed crystals and 14mL of cetyltrimethylammonium bromide (1mol / L) at 40℃ and stirred for 1 hour to obtain solution 5. 0.35g of metal oxide ZrO2 was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0185] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 ml of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-1. The multi-level pore factor (V) micro / V total )×(S meso / S BET The calculated pore factor (HF) of the coating for this catalytic oxidation catalyst is 0.084, corresponding to a mesoporous specific surface area of ​​109.5 m². 2 g -1 The micropore volume is 0.164 cm³. 3 g -1 The active component comprises 0.1% by weight, with a particle size between 3 and 4 nm; the coating particle size is between 80 and 150 nm, the mesopore size distribution is 4.1-5.5 nm, and the specific surface area is approximately 400 m². 2 / g, the powder shedding rate of the coating is 0.1%.

[0186] Nitrogen adsorption-desorption experiments and transmission electron microscopy analysis revealed that the coating particles of the catalytic oxidation catalyst have a multi-level pore structure with spherical cavities inside the pores.

[0187] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 265℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 500 h (i.e., the catalyst activity did not significantly decrease after 500 hours of continuous reaction).

[0188] Example 2

[0189] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0190] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 1g of commercially available ZSM-5 seed crystals and 14mL of tetradecyltrimethylammonium bromide (1mol / L) at 40℃ and stirred for 1 hour to obtain solution 5. 0.35g of TiO2 metal oxide was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0191] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 ml of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-2. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BET The calculated pore factor (HF) of the coating for this catalytic oxidation catalyst is 0.075, corresponding to a mesoporous specific surface area of ​​102.3 m². 2 g -1 The micropore volume is 0.183 cm³. 3 g -1 The active component comprises 0.1% by weight, with a particle size between 3 and 4 nm; the coating particle size is between 80 and 150 nm, the mesopore size distribution is 6-9.5 nm, and the specific surface area is approximately 400 m². 2 / g, the powder shedding rate of the coating is 0.2%.

[0192] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1The reaction pressure was 0.1 MPa, and the reaction temperature was 275℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 450 h (i.e., the catalyst activity did not significantly decrease after 450 h of continuous reaction).

[0193] Example 3

[0194] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0195] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 10g of commercially available ZSM-5 seed crystals and 14mL of dodecyltrimethylammonium bromide (1mol / L) at 40℃ and stirred for 1 hour to obtain solution 5. 0.35g of metal oxide Al2O3 was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0196] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 ml of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-3. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BET The calculated pore factor (HF) of the coating for this catalytic oxidation catalyst is 0.074, corresponding to a mesoporous specific surface area of ​​100.7 m². 2 g -1 The micropore volume is 0.172 cm³.3 g -1 The active component comprises 0.1% by weight, with a particle size between 5 and 6 nm; the coating particle size is between 80 and 150 nm, the mesopore size distribution is 8-19.5 nm, and the specific surface area is approximately 400 m². 2 / g, the powder shedding rate of the coating is 0.2%.

[0197] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 325℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 300 h (i.e., the catalyst activity did not significantly decrease after 300 h of continuous reaction).

[0198] Example 4

[0199] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0200] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 3.5g of commercially available ZSM-5 seed crystals and 30mL of cetyltrimethylammonium bromide (3mol / L) at 40℃ and stirred for 1 hour to obtain solution 5. 0.35g of metal oxide ZrO2 was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0201] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 mL of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-4. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BET The calculated pore size factor (HF) of the coating for this catalytic oxidation catalyst is 0.087. The active component comprises 0.1% by weight, with a particle size between 2 and 3 nm. The coating particle size is between 80 and 150 nm, the mesopore size distribution is 8-19.5 nm, and the specific surface area is approximately 500 m². 2 / g, the powder shedding rate of the coating is 0.2%.

[0202] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 225℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 450 h (i.e., the catalyst activity did not significantly decrease after 450 h of continuous reaction).

[0203] Example 5

[0204] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0205] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 3.5g of commercially available ZSM-5 seed crystals and 14mL of cetyltrimethylammonium bromide (3mol / L) at 40℃ and stirred for 1 hour to obtain solution 5. 1g of metal oxide ZrO2 was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0206] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 ml of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-5. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BET The pore size factor (HF) of the coating of this catalytic oxidation catalyst was calculated to be 0.085. The active component content was 0.1% by weight, with a particle size between 3-4 nm; the coating particle size was between 100-200 nm, the mesoporous pore size distribution was 8-19.5 nm, the specific surface area was approximately 400 m² / g, and the coating powder shedding rate was 0.5%.

[0207] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 275℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 150 h (i.e., the catalyst activity did not significantly decrease after 450 h of continuous reaction).

[0208] Example 6

[0209] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0210] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 3.5g of commercially available ZSM-5 seed crystals and 14mL of hexadecyltrimethylammonium bromide (3mol / L) at 40℃ and stirred for 1 hour to obtain solution 5. 0.35g of metal oxide ZrO2 was added to solution 5, and the mixture was ball-milled for 10 hours to obtain coating slurry 6.

[0211] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 ml of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-6. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BET The calculated pore size factor (HF) of the coating for this catalytic oxidation catalyst is 0.086. The active component comprises 0.1% by weight, with a particle size between 2 and 3 nm. The coating particle size is between 50 and 100 nm, the mesopore size distribution is 8-19.5 nm, and the specific surface area is approximately 550 m². 2 / g, the powder shedding rate of the coating is 0.05%.

[0212] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1The reaction pressure was 0.1 MPa, and the reaction temperature was 215℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 500 h (i.e., the catalyst activity did not significantly decrease after 500 h of continuous reaction).

[0213] Example 7

[0214] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0215] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 3.5g of commercially available ZSM-5 seed crystals and 14mL of cetyltrimethylammonium bromide (3mol / L) at 25℃ and stirred for 1 hour to obtain solution 5. 0.35g of metal oxide ZrO2 was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0216] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 mL of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-7. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BETThe pore size factor (HF) of the coating of this catalytic oxidation catalyst was calculated to be 0.084. The active component content was 0.1% by weight, with a particle size between 2-3 nm; the coating particle size was between 80-150 nm, the mesopore size distribution was 6-12 nm, and the specific surface area was approximately 550 m². 2 / g, the powder shedding rate of the coating is 0.1%.

[0217] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 215℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 500 h (i.e., the catalyst activity did not significantly decrease after 500 h of continuous reaction).

[0218] Example 8

[0219] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0220] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 3.5g of commercially available ZSM-5 seed crystals and 30mL of cetyltrimethylammonium bromide (3mol / L) at 40℃ and stirred for 10 hours to obtain solution 5. 0.35g of metal oxide ZrO2 was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0221] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 ml of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-8. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BET The pore size factor (HF) of the coating of this catalytic oxidation catalyst was calculated to be 0.087. The active component content was 0.1% by weight, with a particle size between 2-3 nm; the coating particle size was between 80-150 nm, the mesopore size distribution was 5-10 nm, and the specific surface area was approximately 600 m². 2 / g, the powder shedding rate of the coating is 0.1%.

[0222] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 195℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 500 h (i.e., the catalyst activity did not significantly decrease after 500 h of continuous reaction).

[0223] Example 9

[0224] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0225] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 3.5g of commercially available ZSM-5 seed crystals and 14mL of cetyltrimethylammonium bromide (3mol / L) at 100℃ and stirred for 1 hour to obtain solution 5. 0.35g of ZrO2 metal oxide was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0226] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 mL of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain catalytic oxidation catalyst Cat-9. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BET The calculated pore size factor (HF) of the coating for this catalytic oxidation catalyst is 0.086. The active component comprises 0.1% by weight, with a particle size between 2 and 3 nm. The coating particle size is between 80 and 150 nm, the mesopore size distribution is 5-8.5 nm, and the specific surface area is approximately 600 m². 2 / g, the powder shedding rate of the coating is 0.1%.

[0227] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 195℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 500 h (i.e., the catalyst activity did not significantly decrease after 500 h of continuous reaction).

[0228] Example 10

[0229] First, take commercially available cordierite honeycomb ceramic with a diameter of 200 cpsi and a diameter of 100×100×50mm, reflux it at 80℃ for 24 hours with 1 mol / L nitric acid, wash it with deionized water until the pH value is 7, and let it air dry for later use.

[0230] Next, 5g of ethanol and 0.568g of sodium aluminate were mixed evenly to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, and 22.58g of tetraethyl orthosilicate and 6.9g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, then heated to 90℃ at a rate of 5-6℃ / min, and the alcohol was removed at 90℃ for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 0.5g of commercially available ZSM-5 seed crystals and 30mL of cetyltrimethylammonium bromide (3mol / L) at 40℃ and stirred for 1 hour to obtain solution 5. 0.35g of ZrO2 metal oxide was added to solution 5, and the mixture was ball-milled for 2 hours to obtain coating slurry 6.

[0231] Then, 0.5 L of a 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200 ml of a 1 mol / L ferric nitrate, cerium nitrate, and lanthanum nitrate mixed solution (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25 °C and pH 9 for 3 h to obtain solution 7. Solution 7 was added to coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Mixed slurry 8 was then dropwise added to acid-treated cordierite honeycomb ceramic, purged with a 2 MPa air knife, treated in a 100 °C drying oven for 12 h, and calcined at 250 °C for 6 h. Then, it was reduced at 400 °C (heating rate 10 °C / min) for 5 h under a 10% H2 and 90% N2 atmosphere to obtain the catalytic oxidation catalyst Cat-10. The multi-level pore factor (V) was then used to determine the catalyst composition. micro / V total )×(S meso / S BET The pore size factor (HF) of the coating of this catalytic oxidation catalyst was calculated to be 0.086. The active component content was 0.1% by weight, with a particle size between 5-6 nm; the coating particle size was between 80-150 nm, the mesopore size distribution was 20-25 nm, and the specific surface area was approximately 300 m². 2 / g, the powder shedding rate of the coating is 0.3%.

[0232] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹.-1 The reaction pressure was 0.1 MPa, and the reaction temperature was 305℃. Gas chromatography was used to detect the CO and VOC concentrations at the reactor outlet. The results showed that CO ≤ 100 ppm, VOCs ≤ 120 ppm, the conversion rate ≥ 99%, and the catalyst stability was 250 h (i.e., the catalyst activity did not significantly decrease after 250 h of continuous reaction).

[0233] Comparative Example 1

[0234] The catalytic oxidation catalyst prepared according to the method of Example 1 differs in that the cordierite honeycomb ceramic is not acid-treated; instead, the coating slurry is directly drop-added to the untreated cordierite honeycomb ceramic to obtain the monolithic catalyst Cat-D1. The catalyst has an active component content of 0.1% by weight, an active component particle size between 5-6 nm, a coating particle size between 100-200 nm, a mesopore size distribution of 10-45 nm, and a specific surface area of ​​approximately 300 m². 2 / g, the powder shedding rate of the coating is 5%.

[0235] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 265℃. The CO and VOC concentrations at the reactor outlet were detected using gas chromatography. The results showed that the CO concentration was approximately 1000 ppm, the VOC concentration was approximately 5000 ppm, the conversion rate was 50%, and the catalyst stability was 10 h.

[0236] Comparative Example 2

[0237] Based on Example 1, the difference lies in that the coating slurry is prepared according to the following process:

[0238] 50g of ZSM-5 molecular sieve (purchased from Nankai Catalyst Company, brand name NKF-5) was mixed with 100g of deionized water and wet-milled to obtain a molecular sieve slurry. 0.5L of a 1mol / L mixed solution of chloroplatinic acid and palladium chloride (platinum-palladium molar ratio 1:1) and 200ml of a 1mol / L mixed solution of ferric nitrate, cerium nitrate, and lanthanum nitrate (ferric-cerium-lanthanum molar ratio 1:1:1) were stirred at 25℃ and pH 9 for 3h to obtain a mixed solution. This mixed solution was added to the molecular sieve slurry and stirred for 30min to obtain a coating slurry. Then, the coating slurry was dropwise added to acid-treated cordierite honeycomb ceramics, and the mixture was sequentially purged, dried, calcined, and reduced to obtain the monolithic catalyst Cat-D2. The active component comprises 0.1% by weight, with a particle size of 5-10 nm, a coating particle size of 500-600 nm, a mesoporous channel size distribution of 0 nm, and a specific surface area of ​​approximately 100 m². 2 / g, the powder shedding rate of the coating is 0.1%.

[0239] The catalyst was packed into a fixed-bed reactor. The feed gas consisted of 95% CO2, 4% CO, and 1% VOCs, with a reaction space velocity of 5000 h⁻¹. -1 The reaction pressure was 0.1 MPa, and the reaction temperature was 275℃. The CO and VOC concentrations at the reactor outlet were detected using gas chromatography. The results showed that the CO concentration was approximately 500 ppm, the VOC concentration was approximately 1000 ppm, the conversion rate was 90%, and the catalyst stability was 1 hour.

[0240] As can be seen from the above examples and comparative examples, the catalytic oxidation catalyst prepared by the present invention exhibits good catalytic effect in the process of catalytic oxidation removal of carbon-based oxygen-containing molecular gases, and the catalyst has significantly better stability, making it suitable for continuous long-term operation.

[0241] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalytic oxidation catalyst, characterized in that, The catalytic oxidation catalyst includes: The carrier is an acid-treated, structured carrier; A coating adhered to the carrier, the coating containing a molecular sieve and a metal oxide, the molecular sieve being a ZSM-5 molecular sieve; and The active component dispersed in the coating contains noble metals and combinations of Fe, La and Ce; In the active component, the molar ratio of the noble metal to the combination of Fe, La and Ce is 1:0.1-0.3; The precious metal is a combination of platinum and palladium; The metal oxide is TiO2 or ZrO2; The coating has a particle size of 50-500 nm, a mesopore size of 3-50 nm, and a specific surface area of ​​300-600 m². 2 / g, wherein the particle size of the active component is 1-8nm; The coating pore factor HF of the catalytic oxidation catalyst is 0.056-0.094, and the coating pore factor HF is calculated using the following formula. HF = (V micro / V total ) × (S meso / S BET ) Among them, V micro Micropore volume, unit: cm 3 g 1 ; V total Total pore volume, in cm. 3 g 1 ; S meso Mesoporous specific surface area, in m³ 2 g 1 ; S BET Total pore surface area, in m² 2 g 1 .

2. The catalytic oxidation catalyst according to claim 1, characterized in that, The coating has a particle size of 80-300 nm, a mesopore size of 4-30 nm, and a specific surface area of ​​350-500 m². 2 / g, wherein the particle size of the active component is 2-6nm.

3. The catalytic oxidation catalyst according to claim 1 or 2, characterized in that, The powder shedding rate of the coating is less than 1%.

4. The catalytic oxidation catalyst according to claim 1 or 2, characterized in that, The powder shedding rate of the coating is 0.1-1%.

5. The catalytic oxidation catalyst according to claim 1 or 2, characterized in that, The content of the coating is 1-10 parts by weight relative to 100 parts by weight of the carrier, and the content of the active component is 0.1-1 parts by weight.

6. The catalytic oxidation catalyst according to claim 1 or 2, characterized in that, The regularized carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier and alumina honeycomb carrier.

7. The catalytic oxidation catalyst according to claim 1 or 2, characterized in that, In the coating, the weight ratio of the molecular sieve to the metal oxide is 1:0.1-0.

5.

8. A method for preparing a catalytic oxidation catalyst as described in any one of claims 1-7, characterized in that, The method includes the following steps: (1) Treat the structured carrier with acid; (2) The alcohol solution of sodium aluminate is mixed with an aqueous solution containing a microporous template agent and a silicon source, aged, and the alcohol is removed. Then the resulting gel solution is mixed with molecular sieve seed crystals and mesoporous template agent. The molecular sieve seed crystals are ZSM-5 molecular sieve seed crystals. (3) The mixed solution obtained in step (2) is mixed with the metal oxide and ball-milled to obtain the coating slurry; (4) The coating slurry is mixed with a mixed solution containing a noble metal precursor and a structural additive. The resulting mixed slurry is added to an acid-treated structured carrier, and then the carrier is purged, dried, calcined and reduced in sequence. In step (2), the mesoporous template agent is an alkyltrimethylammonium halide, wherein the alkyl group has C atoms. x The halogen is 8-18, and the halogen is fluorine, chlorine, or bromine; According to C x The functional relationship between HF and HF is HF = 0.0032C. x + 0.0334 ± 0.003, determined by selecting the carbon number (C) of the alkyl group in the alkyltrimethylammonium halide used as a mesoporous template agent. x Adjust the pore factor HF of the coating of the prepared catalytic oxidation catalyst; The structural additives are selected from ferric nitrate, cerium nitrate, lanthanum nitrate, lanthanum sulfate, lanthanum chloride, cerium sulfate, and cerium trioxide.

9. The method according to claim 8, characterized in that, In step (1), the acid treatment process includes: reflux treatment of the regularized carrier with an acidic solution, followed by washing until neutral and drying.

10. The method according to claim 9, characterized in that, In step (1), the concentration of the acidic solution is 1-3 mol / L.

11. The method according to claim 9, characterized in that, In step (1), the acid in the acidic solution is at least one of nitric acid, sulfuric acid and hydrochloric acid.

12. The method according to claim 9, characterized in that, In step (1), the reflux treatment conditions include: a temperature of 70-90°C and a time of 12-36 hours.

13. The method according to claim 8, characterized in that, In step (2), the specific process of mixing the alcoholic solution of sodium aluminate with the aqueous solution containing the microporous template agent and the silicon source is as follows: the alcoholic solution of sodium aluminate is added to the aqueous solution containing the microporous template agent and the silicon source at a rate of 0.005-0.015 mL / min, and the mixture is stirred for 2-5 hours.

14. The method according to claim 8, characterized in that, In step (2), the microporous template agent is selected from at least one of tetrapropylammonium hydroxide, tetrapropylammonium bromide and tetraethylammonium hydroxide.

15. The method according to claim 8, characterized in that, In step (2), the silicon source is selected from at least one of silicates, silicic acid, silica hydrogel and tetraethyl orthosilicate.

16. The method according to claim 8, characterized in that, In step (2), the concentration of the mesoporous template agent is 0.5-5 mol / L.

17. The method according to claim 8, characterized in that, In step (2), the concentration of the mesoporous template agent is 1-3 mol / L.

18. The method according to claim 8, characterized in that, In step (2), the mesoporous template agent is selected from octaalkyltrimethylammonium bromide, decaalkyltrimethylammonium bromide, dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide and hexadecyltrimethylammonium bromide.

19. The method according to claim 8, characterized in that, In step (3), the metal oxide is selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

20. The method according to claim 8, characterized in that, In step (4), the pH value of the mixed solution containing the noble metal precursor and the structural aid is 9-12.

21. The method according to claim 8, characterized in that, In step (4), the noble metal precursor is selected from chloroplatinic acid, 2-hydroxyethylamine salt of platinum(IV) hydroxyhydroxide, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate and palladium acetate.

22. The method according to claim 8, characterized in that, In step (4), the purging process is performed by purging with a 1.5-2.5MPa air knife.

23. The method according to claim 8, characterized in that, In step (4), the calcination conditions include a temperature of 200-300℃ and a time of 4-10 hours.

24. The method according to claim 8, characterized in that, In step (4), during the reduction process, the reduction atmosphere is H2, CO, a combination of H2 and CO, a mixed atmosphere with different hydrogen concentrations, and a mixed atmosphere with different CO concentrations.

25. The method according to claim 8, characterized in that, In step (4), the reduction conditions include: the catalyst heating rate is 2-20℃ / min, the reduction temperature is 300-450℃, and the reduction time is 1-10h.

26. The application of the catalytic oxidation catalyst according to any one of claims 1-7 in removing carbon-based oxygen-containing molecular gases from exhaust gases.