Catalyst for oxidative removal of low-temperature carbon monoxide and volatile organic compounds as well as preparation method and use method of catalyst

Abstract

The invention provides a catalyst for oxidative removal of low-temperature carbon monoxide and volatile organic compounds as well as a preparation method and a use method of the catalyst. The catalyst comprises a porous catalyst carrier and active components loaded on the porous catalyst carrier, wherein the active components comprise noble metals and at least one or a combination of transition metals and catalytic promoters; wherein the mass ratio of the transition metal to the noble metal is (0-10): 1, the mass ratio of the catalytic promoter to the noble metal is (0-10): 1, and the mass content of the noble metal is 0.1-10% on the basis of the total mass of the catalyst. The catalyst has high catalytic activity and is suitable for low-temperature oxidation removal of carbon monoxide (CO) and volatile organic compounds (VOC) in various application scenes.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a catalyst for the oxidative removal of carbon monoxide and volatile organic compounds at low temperatures, and a method for preparing the same. Background Technology

[0002] Carbon monoxide (CO) and volatile organic compounds (VOCs) are two widespread and significantly harmful air pollutants. CO is highly toxic to humans and animals due to its high affinity for hemoglobin, and even at low concentrations (such as 100 ppm), it reduces the efficiency of oxygen transport in the blood. VOCs, on the other hand, are diverse and are important precursors to environmental problems such as photochemical smog and ozone layer depletion.

[0003] CO and VOCs are generated through a wide range of channels and methods. In industrial waste gas, CO and VOCs often originate from the incomplete combustion of fossil fuels, as well as from industrial production processes and the use and emission of VOCs-containing products. They are characterized by high emission concentrations, large emission volumes, and complex compositions. In addition to industrial emissions, vehicles, aircraft, sewage treatment plants, light industrial facilities, certain small businesses (such as dry cleaners, bakeries, restaurants, etc.), and households also emit CO and VOCs. Among these, VOCs in the home environment mainly come from interior decoration, daily necessities, and human activities. They are characterized by multiple sources, wide distribution, long-term low-concentration release, and a more direct relationship with human health. In particular, formaldehyde, as a major indoor air pollutant, has received increasing attention in recent years due to its carcinogenicity.

[0004] Currently, thermocatalytic oxidation is the mainstream technology for treating this type of waste gas, but it relies on high temperatures (usually above 250°C) to achieve complete oxidation of CO and VOCs, resulting in huge energy consumption and high operating costs. Therefore, developing purification technologies that can operate efficiently at low temperatures or even room temperature has become an urgent need.

[0005] Currently known technologies for the low-temperature removal of VOCs and CO include photocatalysis, electrochemical catalysis, adsorption, and catalytic oxidation. However, achieving complete oxidative removal of VOCs and / or CO at lower temperatures remains a challenging task. Developing oxidation catalysts with higher activity and sufficient stability and durability to achieve complete oxidation of CO and VOCs at lower temperatures is crucial in this field.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a catalyst for the low-temperature oxidation removal of carbon monoxide and volatile organic compounds, as well as its preparation and application methods, which at least solves the technical problems of high energy consumption, high cost, and poor catalyst stability in traditional thermocatalytic oxidation.

[0008] In a first aspect, the present invention provides a catalyst for the low-temperature oxidation removal of carbon monoxide and volatile organic compounds, characterized in that it comprises a porous catalyst support and an active component supported thereon, the active component comprising a noble metal and at least one or a combination thereof selected from transition metals and catalyst promoters; wherein the mass ratio of the transition metal to the noble metal is (0-10):1, the mass ratio of the catalyst promoter to the noble metal is (0-10):1, and the mass content of the noble metal is 0.1%-10% based on the total mass of the catalyst.

[0009] In a second aspect, the present invention provides a structural catalyst comprising a monolithic support and the catalyst described above coated on the monolithic support.

[0010] A third aspect of the present invention provides a method for preparing the catalyst described above, comprising the following steps: (1) Dissolve the precursors of noble metals, transition metals and catalyst promoters to obtain an impregnation solution, load the impregnation solution onto a porous catalyst support, and then dry it to obtain the catalyst described in the first aspect; (2) The catalyst obtained in step (1) is mixed with a binder to form a catalyst slurry, and the catalyst slurry is coated on an integral support, and then dried and calcined to obtain the structural catalyst described in the second aspect.

[0011] In a fourth aspect, the present invention provides a method for oxidatively removing carbon monoxide and volatile organic compounds using the above-mentioned catalyst. Before use, the above-mentioned catalyst or structural catalyst is reduced to convert the active metal component into a reduced state. Then, the gas containing carbon monoxide and / or volatile organic compounds is brought into contact with the reduced catalyst at atmospheric pressure and a temperature not exceeding 150°C for reaction.

[0012] The present invention has at least the following beneficial effects: The catalyst developed in this invention is used for the oxidative removal of CO and VOCs at atmospheric pressure and below about 150 °C. o The reaction is carried out at a temperature of C. VOCs include, but are not limited to, aldehydes, alcohols, alkanes, alkenes, organic acids, and aromatic compounds. In some embodiments, the oxidative removal of CO, formaldehyde, methanol, formic acid, etc., is performed at room temperature; in other embodiments, the complete oxidation of aromatic compounds (e.g., toluene) and long-chain alkanes (e.g., decane) is performed at a temperature of approximately 150°C. o C. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 The in-situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) of the catalyst powders in Example 1 and Comparative Examples 1 and 2 of this invention. Figure 2 The catalyst powders prepared in Examples 1 and 2 and Comparative Examples 1 and 2 of this invention exhibit CO oxidation at room temperature under high reactive gas volume hourly space velocity. Figures 3 to 6 The coating honeycomb catalysts prepared in Examples 1, 3 to 20 and Comparative Examples 1, 3 and 4 of the present invention are shown in the complete oxidation of toluene. Figure 7 , Figure 8 The coating honeycomb catalysts prepared in Examples 19, 21-27 and Comparative Example 5 of this invention exhibit performance in the catalytic oxidation of n-decane. Detailed Implementation

[0015] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0016] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form includes the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0017] It should be noted that if the text uses terms such as "first" or "second", these terms are only used to distinguish similar objects and should not be interpreted as indicating or implying their relative importance, order of precedence, or implicitly indicating the number of technical features indicated. It should be understood that the data in the descriptions of "first" and "second" can be interchanged where appropriate.

[0018] Throughout the accompanying drawings, identical elements are represented by the same or similar reference numerals. Conventional structures or configurations may be omitted where they might cause confusion in understanding the invention. Furthermore, the shapes, dimensions, and positional relationships of the components in the drawings do not reflect actual size, scale, or actual positional relationships. Additionally, any reference symbols placed within parentheses in this invention should not be construed as limiting the scope of the invention.

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] One aspect of the present invention provides a catalyst for the low-temperature oxidation removal of carbon monoxide and volatile organic compounds, characterized in that it comprises a porous catalyst support and an active component supported thereon, the active component comprising a noble metal and at least one selected from transition metals and catalyst promoters; wherein the mass ratio of transition metal to noble metal is (0-10):1, for example 0.2:1, 0.5:1, 1.5:1, 3:1, 6:1, 9:1, etc., and the mass ratio of catalyst promoter to noble metal is (0-10):1, for example 0.2:1, 0.5:1, 1.7:1, 3.5:1, 6:1, 9.5:1, etc., and the mass content of noble metal (i.e., the mass ratio of noble metal to the entire catalyst) is 0.1%-10% based on the total mass of the catalyst, for example 0.3%, 0.8%, 2%, 5%, 7.5%, 9%, etc. Since the active components include at least one of transition metals and catalyst promoters, the mass ratio of transition metals to noble metals and the mass ratio of catalyst promoters to noble metals cannot both be 0 at the same time.

[0021] The catalyst of this invention employs a "multi-component synergistic" design, which avoids relying solely on noble metals. Instead, it introduces transition metals and catalyst promoters to meticulously construct a composite catalytic interface at the atomic / nanoscale, where the components exhibit complementary electron, structural, and functional properties. This synergistic effect effectively overcomes the bottlenecks faced by pure noble metal catalysts at low temperatures, such as adsorption poisoning and low oxygen activation efficiency. Thus, it achieves efficient and stable oxidative removal of CO and various VOCs under low-temperature conditions (e.g., not exceeding 150°C), while also possessing potential cost advantages.

[0022] In some embodiments, the noble metal is selected from at least one of platinum, palladium, rhodium, ruthenium, iridium, and gold. For example, the noble metal can be any one of these, or a combination of two, three, five, etc., and the term "at least one" has the same meaning below. Selecting specific noble metals such as platinum and palladium can provide intrinsically high catalytic activity for carbon monoxide and various volatile organic compounds, ensuring the basis for the catalyst's reaction under low-temperature conditions.

[0023] To significantly increase the number of exposed active sites and substantially improve the utilization efficiency and catalytic reaction rate of noble metals, in some embodiments, the average crystallite size of the noble metal is less than 10 nm, such as 8 nm, 6 nm, 3 nm, 1.3 nm, etc., preferably less than 5 nm. The crystallite size of the noble metal can be calculated using the XRD Scherrer formula.

[0024] In some embodiments, the transition metal is selected from at least one of iron, copper, cobalt, nickel, and manganese. Introducing transition metals such as iron, copper, and cobalt can generate electronic or structural synergistic effects with noble metals, helping to improve catalytic performance and potentially partially replacing noble metals to reduce catalyst costs.

[0025] In some embodiments, the catalyst promoter is selected from at least one of bismuth and tin. Adding catalyst promoters such as bismuth and tin can modify the electronic state of noble metals or provide new active sites, thereby enhancing the redox capability of the catalyst or its selectivity for specific reactants.

[0026] In some embodiments, the porous catalyst support is selected from at least one of CeO2, TiO2, ZrO2, Al2O3, and zeolite. These porous catalyst supports have strong interactions with noble metals, allowing the noble metals to be stably and highly dispersed on the surface of the catalyst support, thereby enhancing the activity and stability of the catalyst.

[0027] In some embodiments, the mass ratio of transition metal to noble metal is (2-4):1, the mass ratio of catalyst promoter to noble metal is (2-4):1, and the mass content of noble metal is 0.5-5%, which can achieve the best balance between catalyst cost and performance while ensuring excellent low-temperature activity.

[0028] Another aspect of the present invention provides a structural catalyst comprising a monolithic support and the aforementioned catalyst coated on the monolithic support. This structural catalyst "structures" a highly active catalyst in a thin-layer form, achieving sufficient and rapid contact between reactants and active sites (high mass transfer efficiency) without significantly increasing system energy consumption (low pressure drop), thereby comprehensively improving the energy efficiency, economy, and safety of the process.

[0029] In some embodiments, the monolithic carrier is selected from at least one of honeycomb ceramic carriers, metal honeycomb carriers, foamed metal carriers, metal wire mesh carriers, corrugated plate carriers, and polymer carriers. Using monolithic carriers such as honeycomb ceramics or metal honeycomb can provide a low-pressure-drop, high-throughput reaction channel for gas-solid catalytic reactions, greatly improving the processing efficiency and energy efficiency in practical applications.

[0030] Another aspect of the present invention provides a method for preparing the above-mentioned catalyst, comprising the following steps: (1) Dissolve the precursors of noble metals, transition metals and catalyst promoters to obtain an impregnation solution, load the impregnation solution onto a porous catalyst support, and then dry to obtain the catalyst. The catalyst can be in powder form and has strong metal-support interaction. (2) The catalyst obtained in step (1) is mixed with a binder (e.g., added to water) to form a catalyst slurry, and the catalyst slurry is coated on an integral support, dried and calcined to obtain a structural catalyst.

[0031] The preparation method of this invention achieves full-chain optimization from "construction of nanoscale active centers" to "structural shaping for macroscale engineering applications" through an integrated process design of "stepwise loading - structuring and in-situ activation", ultimately ensuring that the catalyst obtains the expected low-temperature high performance.

[0032] In some embodiments, in step (1), the precursor of the noble metal is a noble metal salt, preferably including at least one of the soluble salts of platinum, palladium, rhodium, ruthenium, iridium, and gold.

[0033] In some embodiments, the soluble salts of platinum include platinum nitrate, and the soluble salts of palladium include palladium nitrate.

[0034] In some embodiments, the precursor of the transition metal is a transition metal salt, preferably including at least one of soluble salts of iron, copper, cobalt, nickel, and manganese.

[0035] In some embodiments, the precursor of the catalyst includes at least one of bismuth and tin soluble salts, preferably at least one of bismuth nitrate, bismuth acetate, and tin chloride.

[0036] Using soluble salts such as nitrates as precursors ensures that noble metals, transition metals and additives are uniformly mixed in the solution, thereby achieving atomic-level uniform loading and close interaction on the support.

[0037] In some embodiments, loading is performed using initial wet impregnation, rotary evaporation, or spray drying. Techniques such as initial wet impregnation allow the active component precursor solution to be fully and uniformly absorbed by the carrier pores, ensuring a uniform distribution of the subsequently formed active component particles and preventing localized agglomeration. Initial wet impregnation is preferred to achieve more uniform loading of precious metals and additives.

[0038] In some embodiments, drying is carried out at temperatures above 60°C, such as 70°C, 90°C, 110°C, 130°C, etc., preferably between 80-120°C, to effectively and gently remove moisture, preventing the migration and aggregation of active components or damage to the carrier structure due to excessive temperature, and fixing the highly dispersed state. There are no precise requirements for the drying time, as long as the moisture in the sample is removed. If the temperature is above 100°C, drying in an oven for several hours is generally sufficient, or drying overnight in an oven is also acceptable.

[0039] In some embodiments, in step (2), the binder is selected from at least one of boehmite, alumina sol, nano-hydrated alumina, nano-alumina suspension, nano-silica suspension, silica sol, and zirconium acetate. Using specific binders such as boehmite can firmly adhere the catalyst powder to the surface of the monolithic carrier during subsequent coating processes, forming a robust and porous catalytic coating that prevents peeling during use.

[0040] In order to achieve the best balance between coating adhesion and catalyst activity, in some embodiments, the amount of binder added is 2%-20% of the total mass of the catalyst in step (1), for example, 4%, 8%, 11%, 15%, 18%, etc., preferably 5%-10%.

[0041] In order to ensure the formation of a catalytic coating with moderate thickness, uniformity and strong adhesion on the monolithic carrier and to achieve a good balance between activity and pressure drop, in some embodiments, the solid content of the catalyst slurry in step (2) is 15%-50%, for example 18%, 20%, 24%, 29%, 35%, 43%, 48%, etc., preferably 30%-40%.

[0042] In some embodiments, the catalyst slurry is ball-milled to a particle size d before being coated onto the monolithic support. 90 The micrometer size is 5-20 micrometers, preferably 8-15 micrometers, to achieve the optimal balance between coating strength, adhesion, and high-activity specific surface area. This preferred range ensures the formation of a robust, porous, and uniform coating, thereby significantly improving catalytic efficiency and service life. After ball milling, the catalyst slurry can be diluted with deionized water to obtain a suitable coating with an appropriate curing agent content.

[0043] In some embodiments, the monolithic carrier is selected from at least one of honeycomb ceramic carriers, metal honeycomb carriers, foamed metal carriers, wire mesh carriers, corrugated plate carriers, and polymer carriers. The advantages of using monolithic carriers such as honeycomb ceramics or metal honeycomb are as described above.

[0044] In some embodiments, the coating amount of catalyst slurry is 0.02-0.5 g / cm³. 3 For example, 0.04 g / cm³ 3 0.07 g / cm 3 0.1 g / cm 3 0.15 g / cm 3 0.25 g / cm 3 0.4 g / cm 3 0.45 g / cm 3 The preferred concentration is 0.05-0.2 g / cm³. 3 The loading of precious metals is 0.1-10 mg / cm³. 3 For example, 0.3 mg / cm 3 0.6 mg / cm 3 0.9 mg / cm 3 1.5 mg / cm 3 3 mg / cm 3 6 mg / cm 3 9 mg / cm 3 The preferred dosage is 0.5-5 mg / cm³. 3 .

[0045] In order to effectively remove moisture from the slurry, in some embodiments, drying is carried out at a temperature above 70°C for more than 6 hours, such as 15 hours at 75°C, 13 hours at 84°C, 12 hours at 100°C, 7 hours at 115°C, 6.5 hours at 125°C, etc., preferably 9-15 hours at 90-120°C.

[0046] In order to fully decompose and transform the active component precursor into the target oxide or metallic state, and at the same time promote the strong interaction between it and the support to form a stable and highly active crystal structure, in some embodiments, calcination is carried out at 450°C or above for more than 1 hour, such as 3 hours at 470°C, 2.5 hours at 530°C, 1.5 hours at 580°C, etc., preferably 1-3 hours at 500-600°C.

[0047] Another aspect of the present invention provides a method for oxidatively removing carbon monoxide and volatile organic compounds using the above-described catalyst. Before use, the catalyst is reduced to convert the active metal component into a reduced state. Then, a gas containing carbon monoxide and / or volatile organic compounds is brought into contact with the catalyst and reacted at ambient pressure and a temperature not exceeding 150°C, for example, at 145°C, 130°C, or 120°C. Limiting the reaction temperature to ambient pressure and a mild condition not exceeding 150°C fully highlights the catalyst's excellent low-temperature activity and demonstrates significant potential for energy saving and consumption reduction.

[0048] To efficiently and safely reduce active components such as noble metals from their oxide state to a metallic state with higher catalytic activity, thereby "activating" the catalyst, in some embodiments, the reduction treatment is performed under conditions of 300-500 °C. o At temperature C, in a mixed atmosphere of reducing and protective gases, the treatment is carried out for more than 1 hour, preferably 1.5-3 hours.

[0049] In some embodiments, the reducing gas is hydrogen and the protective gas is nitrogen.

[0050] In some embodiments, the contact reaction is carried out at temperatures ranging from room temperature to 150°C, further highlighting the catalyst’s excellent low-temperature activity.

[0051] In some embodiments, the volatile organic compounds include at least one of aldehydes, alcohols, alkanes, alkenes, organic acids, and aromatic compounds. This catalyst possesses broad-spectrum oxidation capabilities, a wide range of applications, and high practical value.

[0052] In some embodiments, the oxidative removal of carbon monoxide, formaldehyde, methanol, or formic acid is carried out at room temperature. The catalyst of the present invention exhibits high removal efficiency for common toxic pollutants such as carbon monoxide and formaldehyde at room temperature, which gives it a significant advantage for immediate application in fields such as indoor air purification and personal safety protection.

[0053] The technical solution of the present invention will be described in detail below through specific embodiments, but the present invention is not limited to the following embodiments.

[0054] Example 1 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidative removal catalyst includes the following steps: (1) Add 10 g of a 10% platinum nitrate solution, 18.04 g of ferric nitrate nonahydrate, 5.81 g of bismuth nitrate pentahydrate, and 0.1 g of concentrated nitric acid to 50 mL of deionized water, stir thoroughly to dissolve, and then load the solution onto 94.0 g of cerium oxide (Solvay ACTALYS® HSA 20) using the initial wet impregnation method. After 100... o Drying at C yielded a catalyst powder containing 1% Pt + 2.5% Fe2O3 + 2.5% Bi2O3 / CeO2. (2) Mix 38 g of the above catalyst powder with 3 g of boehmite alumina powder (Sasol DISPERAL® P2) and add 50 ml of deionized water to form a slurry. Ball mill this slurry to a particle size d. 90 The thickness is 10 micrometers. After rinsing with a small amount of deionized water, a suitable catalyst slurry for coating is obtained, with a solid content of approximately 35-40%. (3) Immerse the cordierite honeycomb carrier in the above catalyst slurry, remove excess slurry from the channels, and dry at 550°C. o Calcination at C for 2 hours yielded a coated honeycomb catalyst, with the catalyst coating amount controlled at 0.07 g / cm³. 3 (Platinum content is 0.7 mg / cm³) 3 ); (4) The catalyst should be reduced before use. Typical operating conditions are: 400 o At C, the mixture was treated for 2 hours in a 5% H2 / N2 atmosphere (where 5% is the volume content of H2 in the mixed gas and the corresponding volume content of N2 is 95%) to further improve the catalyst's reaction activity.

[0055] Example 2 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 1, except that in step (1), the cerium oxide material is replaced with titanium dioxide (Degussa P25).

[0056] Example 3 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 1, except that in step (1), the cerium oxide material is replaced with zirconium dioxide (XZO1501 from Luxfer MEL Technologies).

[0057] Example 4 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 1, except that in step (1), bismuth nitrate pentahydrate is replaced with tin chloride, and the weight ratio of platinum to tin is 1:2.5.

[0058] Example 5 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 1, except that in step (1), the platinum nitrate solution is replaced with a palladium nitrate solution.

[0059] Example 6 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 1, except that in step (1), the platinum nitrate solution is replaced with a mixed solution of platinum nitrate and palladium nitrate, wherein the molar ratio of platinum to palladium is 1.

[0060] Example 7 (1) Add 20 g of a 10% platinum nitrate solution, 11.62 g of bismuth nitrate pentahydrate, and 0.1 g of concentrated nitric acid to 200 mL of deionized water and stir thoroughly to dissolve. Add 93.0 g of cerium oxide (HSA 20) to the above solution and continue stirring to form a slurry. Add the slurry to a 1000 mL rotary evaporator and heat at 100°C. o Rotary evaporation was carried out under C water bath and vacuum conditions to obtain 2%Pt+5%Bi2O3 / CeO2 catalyst powder; (2) Mix 38 g of the above catalyst powder with 3 g of boehmite alumina powder (P2) and add 50 ml of deionized water to form a slurry. Ball mill this slurry to a particle size d. 90 Up to 10 micrometers. Add a small amount of deionized water for rinsing to obtain a suitable catalyst slurry for coating, with a solid content of approximately 35-40%. (3) Immerse the cordierite honeycomb carrier in the above catalyst slurry, remove excess slurry from the channels, and dry at 550°C. o Calcination at C for 2 hours yielded a coated honeycomb catalyst, with the catalyst coating amount controlled at 0.07 g / cm³. 3 (Platinum content is 1.4 mg / cm³) 3 ); (4) The catalyst should be reduced before use. Typical operating conditions are: 400 o At C, under a 5% H2 / N2 atmosphere, the catalyst was treated for 2 hours to further enhance its reaction activity.

[0061] Example 8 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 7, except that the bismuth oxide content is increased to 10% in step (1).

[0062] Example 9 (1) Add 20 g of 10% platinum nitrate solution, 36.08 g of ferric nitrate nonahydrate, 5.81 g of bismuth nitrate pentahydrate, and 0.1 g of concentrated nitric acid to 200 mL of deionized water and stir thoroughly to dissolve. Add 90.5 g of cerium oxide (HSA 20) to the above solution and continue stirring to form a slurry. Add the slurry to a 1000 mL rotary evaporator and heat at 100°C. o Rotary evaporation was carried out under C water bath and vacuum conditions to obtain 2%Pt+5%Fe2O3+2.5%Bi2O3 / CeO2 catalyst powder; (2) Mix 38 g of the above catalyst powder with 3 g of boehmite alumina powder (P2) and add 50 ml of deionized water to form a slurry. Ball mill this slurry to a particle size d. 90 Up to 10 micrometers. Add a small amount of deionized water for rinsing to obtain a suitable catalyst slurry for coating, with a solid content of approximately 35-40%. (3) Immerse the cordierite honeycomb carrier in the above catalyst slurry, remove excess slurry from the channels, and dry at 550°C. o Calcination at C for 2 hours yielded a coated honeycomb catalyst, with the catalyst coating amount controlled at 0.07 g / cm³. 3 (Platinum content is 1.4 mg / cm³) 3 ); (4) The catalyst should be reduced before use. Typical operating conditions are: 400 o At C, under a 5% H2 / N2 atmosphere, the catalyst was treated for 2 hours to further enhance its reaction activity.

[0063] Example 10 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 9, except that the bismuth oxide content is increased to 5% in step (1).

[0064] Example 11 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 9, except that the bismuth oxide content is increased to 7.5% in step (1).

[0065] Example 12 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 9, except that the bismuth oxide content is increased to 10% in step (1).

[0066] Example 13 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 9, except that the bismuth oxide content is increased to 15% in step (1).

[0067] Example 14 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 9, except that the catalyst coating amount is controlled to 0.14 g / cm³ in step (3). 3 (Platinum content 2.8 mg / cm³) 3 ).

[0068] Example 15 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 10, except that the catalyst coating amount is controlled to 0.14 g / cm³ in step (3). 3 (Platinum content 2.8 mg / cm³) 3 ).

[0069] Example 16 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 11, except that the catalyst coating amount is controlled to 0.14 g / cm³ in step (3). 3 (Platinum content 2.8 mg / cm³) 3 ).

[0070] Example 17 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 12, except that the catalyst coating amount is controlled to 0.14 g / cm³ in step (3). 3 (Platinum content 2.8 mg / cm³) 3 ).

[0071] Example 18 (1) Add 40 g of a 10% platinum nitrate solution, 23.24 g of bismuth nitrate pentahydrate, and 0.1 g of concentrated nitric acid to 200 mL of deionized water and stir thoroughly to dissolve. Add 86.0 g of cerium oxide (HSA 20) to the above solution and continue stirring to form a slurry. Add the slurry to a 1000 mL rotary evaporator and heat at 100°C. o Rotary evaporation was carried out under C water bath and vacuum conditions to obtain 4%Pt+10%Bi2O3 / CeO2 catalyst powder; (2) Mix 38 g of the above catalyst powder with 3 g of boehmite alumina powder (P2) and add 50 ml of deionized water to form a slurry. Ball mill this slurry to a particle size d. 90 Up to 10 micrometers. Add a small amount of deionized water for rinsing to obtain a suitable catalyst slurry for coating, with a solid content of approximately 35-40%. (3) Immerse the cordierite honeycomb carrier in the above catalyst slurry, remove excess slurry from the channels, and dry at 550°C. o Calcination at C for 2 hours yielded a coated honeycomb catalyst with a coating amount of 0.07 g / cm³. 3 (Platinum content 2.8 mg / cm³) 3 ); (4) The catalyst should be reduced before use. Typical operating conditions are: 400 o At C, under a 5% H2 / N2 atmosphere, the catalyst was treated for 2 hours to further enhance its reaction activity.

[0072] Example 19 (1) Add 40 g of 10% platinum nitrate solution, 36.08 g of ferric nitrate nonahydrate, 23.24 g of bismuth nitrate pentahydrate, and 0.1 g of concentrated nitric acid to 200 mL of deionized water and stir thoroughly to dissolve. Add 81.0 g of cerium oxide (HSA2O) to the above solution and continue stirring to form a slurry. Add the slurry to a 1000 mL rotary evaporator and heat at 100°C. o Rotary evaporation was carried out under C water bath and vacuum conditions to obtain 4%Pt+5%Fe2O3+10%Bi2O3 / CeO2 catalyst powder; (2) Mix 38 g of the above catalyst powder with 3 g of boehmite alumina powder (P2) and add 50 ml of deionized water to form a slurry. Ball mill this slurry to a particle size d. 90 Up to 10 micrometers. Add a small amount of deionized water for rinsing to obtain a suitable catalyst slurry for coating, with a solid content of approximately 35-40%. (3) Immerse the cordierite honeycomb carrier in the above catalyst slurry, remove excess slurry from the channels, and dry at 550°C. oCalcination at C for 2 hours yielded a coated honeycomb catalyst with a coating amount of 0.07 g / cm³. 3 (Platinum content 2.8 mg / cm³) 3 ); (4) The catalyst should be reduced before use. Typical operating conditions are: 400 o At C, under a 5% H2 / N2 atmosphere, the catalyst was treated for 2 hours to further enhance its reaction activity.

[0073] Example 20 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 19, except that the iron oxide content is increased to 10% in step (1).

[0074] Example 21 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 19, except that the catalyst coating amount is controlled to 0.035 g / cm³ in step (3). 3 (Platinum content 1.4 mg / cm³) 3 ).

[0075] Example 22 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 19, except that the catalyst coating amount is controlled to 0.105 g / cm³ in step (3). 3 (Platinum content 4.2 mg / cm²) 3 ).

[0076] Example 23 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 19, except that the catalyst coating amount is controlled to 0.14 g / cm³ in step (3). 3 (Platinum content 5.6 mg / cm²) 3 ).

[0077] Example 24 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 22, except that the bismuth oxide content is adjusted to 4% when preparing the powder in step (1).

[0078] Example 25 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 22, except that the bismuth oxide content is adjusted to 8% when preparing the powder in step (1).

[0079] Example 26 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 22, except that the bismuth oxide content is adjusted to 12% when preparing the powder in step (1).

[0080] Example 27 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Example 22, except that the bismuth oxide content is adjusted to 16% when preparing the powder in step (1).

[0081] Comparative Example 1 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidative removal catalyst includes the following steps: (1) Add 10 g of a 10% platinum nitrate solution to 50 mL of deionized water, stir thoroughly to dissolve, and then load the solution onto 99.0 g of cerium oxide (HSA 20) using the initial wet impregnation method. After 100... o Drying at C yields 1% Pt / CeO2 catalyst powder; (2) Mix 38 g of the above catalyst powder with 3 g of boehmite alumina powder (P2) and add 50 ml of deionized water to form a slurry. Ball mill this slurry to a particle size d. 90 Up to 10 micrometers. Add a small amount of deionized water for rinsing to obtain a suitable catalyst slurry for coating, with a solid content of approximately 35-40%. (3) Immerse the cordierite honeycomb carrier in the above catalyst slurry, remove excess slurry from the channels, and dry at 550°C. o Calcination at C for 2 hours yielded a coated honeycomb catalyst, with the catalyst coating amount controlled at 0.07 g / cm³. 3 (Platinum content 0.7 mg / cm³) 3 ); (4) The catalyst should be reduced before use. Typical operating conditions are: 400 o At temperature C, under a 5% H2 / N2 atmosphere, the catalyst was treated for 2 hours to further enhance its reactivity.

[0082] Comparative Example 2 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Comparative Example 1, except that in step (1), the cerium oxide material is replaced with titanium dioxide (P25).

[0083] Comparative Example 3 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Comparative Example 1, except that the platinum content is increased to 2% in step (1), and the catalyst coating amount is controlled to be 0.07 g / cm³. 3 (Platinum content 1.4 mg / cm³) 3 ).

[0084] Comparative Example 4 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst is basically the same as the preparation method in Comparative Example 3, except that the catalyst coating amount is controlled to 0.14 g / cm³. 3 (Platinum content 2.8 mg / cm³) 3 ).

[0085] Comparative Example 5 A method for preparing a low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidative removal catalyst is basically the same as the preparation method in Comparative Example 3, except that the platinum content in the catalyst powder is increased to 4%, and the catalyst coating amount is controlled at 0.105 g / cm³. 3 (Platinum content 4.2 mg / cm²) 3 ).

[0086] Performance testing Take the catalyst powders prepared in step (1) of Example 1, Comparative Example 1, and Comparative Example 2, and heat them at 550°C. o Calcination at C for 2 hours, and then at 400 o Under a 5% H2 / N2 atmosphere, the mixture was treated for 2 hours. In-situ spectroscopic analysis was performed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to measure the CO adsorption spectrum under reaction conditions of room temperature, 500 ppm CO, and 20% O2. Figure 1 As shown.

[0087] In-situ DRIFTS can monitor carbon monoxide adsorbed on the surface of different catalysts under real reaction conditions, thus providing important clues for the study of reaction mechanisms. Figure 1In-situ DRIFTS spectra of linear CO adsorption on the surface of three catalysts are shown: 1% Pt / TiO2 (prepared in Comparative Example 2), 1% Pt / CeO2 (prepared in Comparative Example 1), and (1% Pt + 2.5 Fe2O3 + 2.5% Bi2O3) / CeO2 (prepared in Example 1). The TiO2 used in the samples was Degussa P25, and the CeO2 used was Solvay ACTALYS® HSA 20.

[0088] Depend on Figure 1 It is evident that the adsorption of CO by Comparative Example 1 is much less than that by Comparative Example 2, while the adsorption of CO by Comparative Examples 1 and 2 is much greater than that by Example 1. This indicates that compared with titanium dioxide, cerium oxide has a smaller adsorption capacity for CO, and the doping of bismuth iron further reduces the surface adsorption capacity of the catalyst for CO, thus greatly reducing catalyst poisoning caused by strong CO adsorption.

[0089] Correspondingly, by appendix Figures 2 to 8 It is evident that the catalytic activity of all comparative examples (Comparative Examples 1-5) in the catalytic oxidation reactions of CO and various VOCs involved in this invention is lower than that of the catalysts in the examples with appropriate doping at the same noble metal content.

[0090] Figure 1 Linear adsorption CO peaks (~2100-2050 cm⁻¹) can also be observed on 1% Pt / TiO₂. - The strength (nearly ¹) is much higher than that of 1% Pt / CeO2 and (1% Pt + 2.5 Fe2O3 + 2.5% Bi2O3) / CeO2. This indicates that: (1) The 1% Pt / TiO2 catalyst surface has more exposed Pt sites available for CO adsorption. However, reaction data (e.g.) Figure 2 As shown in the figure, the CO oxidation activity of 1% Pt / TiO2 is actually lower. Therefore, the limiting step for CO conversion on these catalysts is not CO adsorption, but oxygen activation or surface reaction. Excessive strong CO adsorption can actually "poison" the Pt active sites, hindering the reaction (i.e., self-poisoning mechanism).

[0091] (2) The addition of bismuth and iron further reduced the adsorbed CO, possibly because they partially covered the Pt sites, preventing strong CO adsorption and thus leaving more active sites for oxygen activation. Additionally, since the in-situ DRIFTS test atmosphere contains oxygen, some CO molecules undergo in-situ oxidation on the catalyst surface within the sample cell. Because the Pt / CeO2 system exhibits stronger catalytic activity for CO oxidation, this also resulted in a significantly weaker CO signal in the Pt / CeO2 system, especially in the bismuth-doped Pt+Fe / CeO2 sample, where only extremely weak CO adsorption was observed.

[0092] (3) This confirms that bismuth iron doping can effectively suppress the strong adsorption of CO on Pt sites, thereby avoiding catalyst poisoning.

[0093] In other low-temperature oxidation reactions of VOCs, CO is often an intermediate product or a byproduct of incomplete oxidation, and it is easily adsorbed by the active sites on the catalyst surface, causing catalyst poisoning. The above DRIFTS test results also explain the promoting effect of bismuth-iron doping on the catalytic activity of the Pt / CeO2 system during low-temperature VOC oxidation and removal.

[0094] Figure 2 To compare the catalytic activity of different catalysts in CO oxidation at room temperature. Due to the high activity of the platinum-based catalysts supported on P25 (TiO2) and HSA20 (CeO2), all catalysts exhibited nearly 100% CO conversion at low operating gas hourly space velocities. To compare the catalyst activity, catalyst powder was used in the tests: catalyst powders prepared in step (1) of Examples 1, 2, Comparative Example 1, and Comparative Example 2 were used and tested at 550 °C. o Calcination at C for 2 hours, and then at 400 o Treatment was performed for 2 hours at C, under a 5% H2 / N2 atmosphere, with a working gas volume hourly space velocity (VHSV) of 500 K. From Figure 2 It can be seen that bismuth and iron doping significantly improve catalyst activity. When the CO concentration is 500 ppm and the O2 concentration is >1%, the catalyst activity ranking is as follows: (1%Pt+2.5Fe2O3+2.5%Bi2O3) / CeO2 (prepared in Example 1) > (1%Pt+2.5Fe2O3+2.5%Bi2O3) / TiO2 (prepared in Example 2) > 1%Pt / CeO2 (prepared in Comparative Example 1) > 1%Pt / TiO2 (prepared in Comparative Example 2).

[0095] When the O2 concentration is <1%, the catalyst supported on CeO2 exhibits better catalytic activity due to the better oxygen release capacity of CeO2.

[0096] Figures 3 to 6 The performance of the catalyst in the catalytic oxidation and removal of toluene is shown. The coated honeycomb catalysts prepared in Examples 1, 3 to 20, and Comparative Examples 1, 3, and 4 were used in the tests, with a catalyst loading of 0.07 g / cm³. 3 The test conditions were: toluene 500 ppm, O2 20%, and gas hourly space velocity (VHSV) 10000 / h.

[0097] Figure 3It can be seen that bismuth-iron doping can significantly increase catalyst activity. When the platinum content is 1%, the complete conversion temperature T of toluene is reduced to 2.5% when bismuth oxide is doped. 90 (>90% conversion) From 173 o C (Comparative Example 1) decreased to 158 o C (Example 1); The catalyst activity using a cerium oxide (HSA20) support (Example 1) was significantly higher than that using a zirconium oxide (XZO1501) support (Example 3). The activity of 1% bismuth-iron doped noble metal catalysts (including platinum, palladium, and alloys with a platinum-palladium molar ratio of 1) in the toluene oxidation reaction was investigated. The order of activity was: platinum-based catalyst (Example 1) was basically equivalent to the platinum-palladium alloy catalyst (Example 6), but higher than the palladium-based catalyst (Example 5). Tin doping slightly improved the activity compared to undoped catalysts (Example 4).

[0098] Figure 4 The effect of bismuth-iron doping on the reaction activity was compared under the same catalyst coating amount. It can be seen that at a platinum content of 1.4 mg / cm³... 3 At 2% Pt, the reactivity of bismuth-iron doped (2% Pt + 5% Fe2O3 + 5% Bi2O3 / HSA20, Example 10) was superior to that of bismuth doped (2% Pt + 5% Bi2O3 / HSA20, Example 7). Both were significantly better than the undoped Comparative Example 3, but further increasing the doping of bismuth oxide actually decreased the activity (Example 8). Increasing the platinum content improved the reactivity; a platinum content of 2.8 mg / cm³ increased the reactivity. 3 The activity of (4% Pt) was superior to that of platinum with a content of 1.4 mg / cm³. 3 The samples were similar. Bismuth-iron doping (Example 19) showed better activity than bismuth doping (Example 18), and further increasing iron doping (Example 20) also led to a decrease in activity.

[0099] Depend on Figure 5 (The platinum content of all coated honeycomb samples was controlled at 1.4 mg / cm³) 3 It can be seen that appropriate doping of bismuth-iron can significantly increase catalyst activity. When the platinum content in the catalyst powder is 2% and the iron oxide content is 5%, doping with bismuth oxide to 5% results in a significantly higher complete conversion temperature T of toluene. 90 (>90% conversion) from 160 o C dropped to 138 o C (Example 10). Further increasing the bismuth oxide doping amount resulted in a significant decrease in catalytic activity. When the bismuth oxide doping amount reached 15% (Example 13), the complete conversion temperature of toluene increased to 150°C. o Around C. This may be because the excessive doping of bismuth oxide covers the active sites of platinum, making it difficult for toluene and oxygen to be adsorbed by the catalyst.

[0100] from Figures 3 to 6 It can be seen that increasing the platinum content from 1% to 2% and then to 4% (with the catalyst coating amount remaining unchanged, and the platinum loading increasing from 0.7 mg / cm³) results in a significant increase in platinum content. 3 (Example 1) Increased to 1.4 mg / cm 3 (Example 3), and 2.8 mg / cm 3 (Example 4)), the complete oxidation temperature of toluene is thus greatly reduced. Similarly, as Figure 6 As shown, at a platinum loading of 2.8 mg / cm³... 3 At that time, appropriate doping of bismuth oxide significantly increased the catalyst activity. When the bismuth oxide / platinum ratio was 3.75 (Example 16), the complete conversion temperature of toluene decreased to 118°C. o C. Further increasing the bismuth doping to a bismuth oxide / platinum ratio of 5 (Example 17) resulted in a decrease in catalyst activity. This trend is consistent with a platinum content of 1.4 mg / cm³. 3 The catalysts are very similar. Additionally, a comparison... Figure 5 and Figure 6 It can be seen that the bismuth-doped iron has a concentration of 1.4 mg / cm³. 3 The catalytic activity of the platinum-containing sample was even better than that of the undoped sample at 2.8 mg / cm³. 3 Catalysts with platinum content (Comparative Example 4).

[0101] Figure 7 and Figure 8 The performance of Pt / CeO2 series catalysts in the catalytic oxidation of n-decane was observed. The coated honeycomb catalysts prepared in Examples 19, 21 to 27, and Comparative Example 5 were used in the tests. The test conditions were: n-decane 100 ppm, O2 20%, and gas hourly space velocity (GHSV) 10000 / h. Figure 7 As can be seen, similar to toluene oxidation, appropriate doping of bismuth oxide can significantly increase catalyst activity. When the iron and platinum contents remain constant, and the bismuth oxide / platinum ratio is increased to 2.5 (Example 22), the complete conversion temperature T of n-decane increases. 90 (>90% conversion) gradually from 130 o C (Comparative Example 5) decreased to 102 o C. Further increasing the bismuth oxide doping amount significantly reduces the catalytic activity. When the bismuth oxide / platinum ratio increases to 4, the complete conversion temperature of n-decane rises to 135°C. o Around C. Figure 8 The effect of platinum content on the complete conversion of n-decane is shown in the case of bismuth-iron doping. Platinum content ranges from 1.4 mg / cm³. 3 Increased to 4.2 mg / cm 3 The complete conversion temperature of n-decane is from 125°C. o C dropped to 108o C, further increasing the platinum content did not result in a significant increase in catalyst activity. Additionally, compared to Comparative Example 5 (platinum content 4.2 mg / cm³),... 3 A catalyst with appropriate bismuth-iron doping (Example 21, platinum content 1.4 mg / cm³). 3 The higher activity further demonstrates the role of bismuth-iron doping in the oxidation of noble metal catalysts in VOCs.

[0102] The low-temperature carbon monoxide (CO) and volatile organic compound (VOC) oxidation removal catalyst of this invention can be widely used in the emission treatment of CO and VOC in flue gas. Due to its excellent low-temperature catalytic activity, it can also be used for the oxidative removal of small molecule VOCs such as CO and formaldehyde at room temperature, as well as for the selective oxidation (PROX) of CO in the presence of other gases. The flue gas can be air at room temperature or chemical tail gas at medium and low temperatures.

[0103] The catalyst of this invention for the oxidative removal of carbon monoxide and volatile organic compounds at low temperatures can achieve room temperature oxidative removal of CO and small molecule VOCs, represented by formaldehyde. It can also remove some aldehydes, alcohols, alkanes, alkenes, organic acids, and aromatic compounds at 150°C. o Complete oxidation and removal are achieved below °C. This solves the technical problems of high energy consumption and poor stability in traditional thermocatalysis.

[0104] The preparation method of the present invention can prepare catalysts and structural catalyst products with high catalytic activity suitable for various application scenarios for the low-temperature oxidation and removal of carbon monoxide (CO) and volatile organic compounds (VOCs) (such as aromatic compounds (e.g., toluene) and long-chain alkanes (e.g., n-decane)).

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst for the low-temperature oxidation removal of carbon monoxide and volatile organic compounds, characterized in that, The catalyst includes a porous catalyst support and an active component supported thereon, the active component including a noble metal and at least one or a combination thereof selected from transition metals and catalyst promoters; wherein the mass ratio of the transition metal to the noble metal is (0-10):1, the mass ratio of the catalyst promoter to the noble metal is (0-10):1, and the mass content of the noble metal is 0.1%-10% based on the total mass of the catalyst.

2. The catalyst according to claim 1, characterized in that, The precious metal is selected from at least one of platinum, palladium, rhodium, ruthenium, iridium, and gold; Preferably, the average crystallite size of the noble metal is less than 10 nm, and more preferably less than 5 nm.

3. The catalyst according to claim 1 or 2, characterized in that, The transition metal is selected from at least one of iron, copper, cobalt, nickel, and manganese; Preferably, the catalyst is selected from at least one of bismuth and tin; Preferably, the porous catalyst support is selected from at least one of CeO2, TiO2, ZrO2, Al2O3, and zeolite.

4. The catalyst according to any one of claims 1 to 3, characterized in that, The mass ratio of the transition metal to the noble metal is (2-4):1, the mass ratio of the catalyst promoter to the noble metal is (2-4):1, and the mass content of the noble metal is 0.5-5%.

5. A structural catalyst, characterized in that, The structural catalyst includes a monolithic support and the catalyst of any one of claims 1 to 4 coated on the monolithic support; Preferably, the integral carrier is selected from at least one of the following: honeycomb ceramic carrier, metal honeycomb carrier, foam metal carrier, metal wire mesh carrier, corrugated plate carrier, and polymer carrier.

6. A method for preparing a catalyst according to any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Dissolve the precursors of noble metals, transition metals and catalyst promoters to obtain an impregnation solution, load the impregnation solution onto a porous catalyst support, and then dry to obtain the catalyst according to any one of claims 1 to 4; (2) The catalyst obtained in step (1) is mixed with a binder to form a catalyst slurry, and the catalyst slurry is coated on an integral support, and then dried and calcined to obtain the structural catalyst of claim 5.

7. The preparation method according to claim 6, characterized in that, In step (1), the precursor of the precious metal is a precious metal salt, preferably including at least one of the soluble salts of platinum, palladium, rhodium, ruthenium, iridium, and gold; Preferably, the soluble salts of platinum include platinum nitrate, and the soluble salts of palladium include palladium nitrate; Preferably, the precursor of the transition metal is a transition metal salt, preferably including at least one of the soluble salts of iron, copper, cobalt, nickel, and manganese; Preferably, the precursor of the catalyst includes at least one of soluble salts of bismuth and tin, and more preferably includes at least one of bismuth nitrate, bismuth acetate, and tin chloride; Preferably, the loading is carried out by initial wet impregnation, rotary evaporation or spray drying; Preferably, the drying is carried out at a temperature above 60°C, and more preferably between 80-120°C.

8. The preparation method according to claim 6 or 7, characterized in that, In step (2), the binder is selected from at least one of boehmite, aluminum sol, nano hydrated alumina, nano alumina suspension, nano silica suspension, silica sol, and zirconium acetate. Preferably, the amount of binder added is 2%-20% of the total mass of the catalyst obtained in step (1), and more preferably 5%-10%; Preferably, the solid content of the catalyst slurry is 15%-50%, more preferably 30%-40%; Preferably, the integral carrier is selected from at least one of the following: honeycomb ceramic carrier, metal honeycomb carrier, foam metal carrier, metal wire mesh carrier, corrugated plate carrier, and polymer carrier; Preferably, the coating amount of the catalyst slurry during coating is 0.02-0.5 g / cm³. 3 The preferred concentration is 0.05-0.2 g / cm³. 3 The loading of precious metals is 0.1-10 mg / cm³. 3 Preferred concentration: 0.5-5 mg / cm³ 3 ; Preferably, the drying is carried out at a temperature above 70°C for more than 6 hours, and more preferably at a temperature of 90-120°C for 9-15 hours; Preferably, the calcination is carried out at a temperature above 450°C for more than 1 hour, and more preferably at a temperature of 500-600°C for 1-3 hours.

9. A method for oxidatively removing carbon monoxide and volatile organic compounds using the catalyst according to any one of claims 1 to 5, characterized in that, Before use, the catalyst is reduced to convert the active metal components into a reduced state. Then, a gas containing carbon monoxide and / or volatile organic compounds is brought into contact with the reduced catalyst at atmospheric pressure and a temperature not exceeding 150°C to react.

10. The method according to claim 9, characterized in that, The operating conditions for the reduction process are 300-500. o Under temperature C, in a mixed atmosphere of reducing and protective gases, the treatment lasts for 1 hour or more, preferably 1.5-3 hours. Preferably, the reducing gas is hydrogen and the protective gas is nitrogen; Preferably, the contact reaction is carried out at a temperature from room temperature to 150°C; Preferably, the volatile organic compound includes at least one of aldehydes, alcohols, alkanes, alkenes, organic acids, and aromatic compounds; Preferably, the oxidative removal of carbon monoxide, formaldehyde, methanol, or formic acid is carried out at room temperature.

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