Monolithic catalyst and method for its preparation and use

Abstract

The application relates to the technical field of catalyst preparation, and discloses a monolithic catalyst and a preparation method and application thereof.The method comprises the following steps: (1) acid treatment is performed on a regular carrier; (2) an alcohol solution of a titanium source is mixed with an aqueous solution containing a micropore template agent and a silicon source, aging is performed, alcohol is removed, and then the obtained gel solution is mixed with titanium-silicon molecular sieve seeds and a mesopore template agent; (3) the mixed solution obtained in the step (2) is mixed with a metal oxide, ball milling is performed, and a coating slurry is obtained; (4) the coating slurry is mixed with a mixed solution containing a noble metal precursor and optional structure assistants, the obtained mixed slurry is added into the acid-treated regular carrier, and then purging, drying, calcination and reduction are sequentially performed. The monolithic catalyst prepared by the application has good catalytic effect in the process of catalyzing and oxidizing carbon-based oxygen-containing molecular gas, and the stability of the catalyst is obviously better, so the catalyst is suitable for continuous long-period operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalyst preparation, in particular to a monolithic catalyst, a preparation method and application thereof, more particularly to a carbon-based oxygen-containing molecular gas catalytic oxidation monolithic catalyst, a preparation method and application thereof in catalytic oxidation of carbon-based oxygen-containing molecular gas. BACKGROUND

[0002] Carbon monoxide (CO) is a colorless, odorless, toxic gas, which is generally derived from incomplete combustion or partial oxidation of coal, gasoline and natural gas, etc. CO has strong binding force with hemoglobin, thus has strong toxicity, and when the concentration is high, it can cause different degrees of poisoning symptoms in people, harm the brain, heart, liver, kidney, lung and other tissues of the human body, and even cause electric shock-like death, and the minimum lethal concentration for human inhalation is 5000 ppm (5 minutes). Therefore, in the production process of petroleum chemical products, the emission content of CO in tail gas should be strictly required. With the increasingly stringent environmental protection requirements, the concentration of CO in tail gas of chemical plants in Beijing, Zibo and other regions has been strictly restricted.

[0003] In some chemical production processes, the tail gas produced contains low concentration of CO gas (<20000 ppm) (such as the resolved gas and CO2 product gas of the low-temperature methanol washing device used in the acid gas removal of coal gasification device, etc.), for this kind of tail gas, the recovery cost is high, in order to meet the emission requirements, adsorption, photocatalysis, low-temperature plasma conversion, combustion and other methods are usually used to remove CO therein. Among them, catalytic oxidation method is introduced into high-efficiency catalyst on the basis of combustion method, which can reduce the combustion process temperature, has the advantages of simple process and high removal efficiency, and thus has attracted widespread attention. In the directed oxidation process of carbon-based small molecules in petroleum chemical production process, incomplete reaction often occurs, which leads to the enrichment of oxygen-containing small molecule gas in the tail gas discharged from the device or the circulating carrier gas, resulting in not only the risk of combustion and explosion in the chemical production process, but also the formation of photochemical phenomenon, causing pollution to the surrounding environment. At present, the main treatment method for oxygen-containing small molecule tail gas discharged from the oxidation process of petrochemical plants is catalytic oxidation method, which can completely oxidize oxygen-containing small molecule gas to form carbon dioxide. In order to adapt to the requirements of low pressure drop and large gas volume, currently catalytic oxidation method generally uses monolithic catalyst loaded with noble metal, however, the pore distribution of coating matrix is uneven and cannot be controlled, which leads to the problems of poor shape selectivity, low selectivity and poor activity of the catalyst.

[0004] Patent application CN102689911A uses microwave alkali treatment method to corrode nanoscale ZSM-5 molecular sieve, and prepare multi-level pore ZSM-5 molecular sieve nanoballs with adjustable pore size of 30-150 nm. However, the preparation methods of these multi-level pore molecular sieves all have the problems of high preparation cost and complex process, which is not conducive to large-scale production.

[0005] Patent application CN107720771A discloses a preparation method of macroporous-microporous molecular sieve catalyst TS-1, which uses mesoporous silica microspheres as a hard template and a silicon source, and controls the synthesis of macroporous-microporous molecular sieve catalyst with adjustable macropore size by adjusting the reaction temperature, reaction time and the amount of structure-directing agent. However, the molecular sieve prepared only introduces macropore size, and cannot be adjusted, which is difficult to flexibly adapt to the changing properties of raw materials.

[0006] Patent application CN111408342A discloses a high-silicon composite molecular sieve adsorbent for VOCs removal and a preparation method thereof. The method performs hydrothermal crystallization treatment under microwave conditions to control the surface hydrophobicity of the molecular sieve channel, but does not change the channel structure and size, and cannot fully utilize the shape-selective catalytic ability.

[0007] Therefore, developing a catalyst with adjustable channel, high efficiency, low cost, environmental friendliness and strong durability has become a research hotspot and application trend of catalytic oxidation catalysts at home and abroad. SUMMARY

[0008] The purpose of the present application is to provide an integrated catalyst, a preparation method and application thereof for the efficient removal of carbon-based oxygen-containing molecular gas (such as CO, VOCs, etc.) in the exhaust gas of chemical production process. In the present application, the coating structure of the integrated catalyst is adjusted to promote the dispersion of active noble metal and the exposure of active phase, efficiently construct the catalytic active site on the surface of the catalyst, reduce the content of noble metal catalyst, increase the adsorption capacity of carbon-based oxygen-containing molecular gas and oxygen, promote the adsorption and activation of oxygen, and thus improve the catalytic efficiency of the catalyst.

[0009] To achieve the above-mentioned purpose, the present application provides an integrated catalyst, which comprises:

[0010] a carrier, which is a regular carrier treated by acid;

[0011] a coating attached to the carrier, the coating containing titanium-silicon molecular sieve and metal oxide; and

[0012] an active component dispersed in the coating, the active component containing noble metal and optional alloy metal;

[0013] The powder loss rate of the coating is 1% or less, preferably 0.1-1%; and the particle size of the active component is 2-3 nm.

[0014] Preferably, the particle size of the coating is 50-500 nm.

[0015] Preferably, the mesopore size of the coating is 1-50 nm, and the specific surface area is 300-600 m2 / g.

[0016] Preferably, 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, relative to 100 parts by weight of the carrier.

[0017] Preferably, the shaped 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.

[0018] Preferably, in the coating, the weight ratio of the titanium silicalite molecular sieve to the metal oxide is 1:0.1-0.5.

[0019] Preferably, the titanium silicalite molecular sieve is TS-1 molecular sieve.

[0020] Preferably, the metal oxide is selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

[0021] Preferably, in the active component, the molar ratio of the noble metal to the alloy metal is 1:0.1-0.3.

[0022] Preferably, the noble metal is at least one of silver, ruthenium, rhodium, palladium, osmium, iridium and platinum, more preferably a combination of platinum and palladium.

[0023] Preferably, the alloy metal is at least one of Fe, La and Ce, more preferably a combination of La and Ce.

[0024] The second aspect of the present application provides a preparation method of a monolithic catalyst, which comprises the following steps:

[0025] (1) acid treatment of a shaped carrier;

[0026] (2) mixing of an alcohol solution of a titanium source with an aqueous solution containing a micropore template agent and a silicon source, aging, alcohol removal, and then mixing of the obtained gel solution with titanium silicalite molecular sieve seeds and a mesopore template agent;

[0027] (3) mixing of the mixed solution obtained in step (2) with a metal oxide, ball milling to obtain a coating slurry;

[0028] (4) mixing of the coating slurry with a mixed solution containing a noble metal precursor and optionally a structural aid, adding the obtained mixed slurry to the acid-treated shaped carrier, and then sequentially performing purging, drying, calcination and reduction.

[0029] Preferably, in step (1), the acid treatment process comprises: refluxing the shaped support with an acid solution, then washing to neutral and drying.

[0030] Preferably, the acid solution has a concentration of 1-3 mol / L.

[0031] Preferably, the acid in the acid solution is at least one of nitric acid, sulfuric acid and hydrochloric acid.

[0032] Preferably, the refluxing conditions comprise: a temperature of 70-90℃, and a time of 12-36 hours.

[0033] Preferably, the shaped support is at least one of cordierite honeycomb support, mullite honeycomb support, diamond honeycomb support, corundum honeycomb support, zircon corundum honeycomb support, quartz honeycomb support, nepheline honeycomb support, feldspar honeycomb support and alumina honeycomb support.

[0034] Preferably, in step (2), the specific process of mixing the alcohol solution of titanium source with the aqueous solution containing microporous template agent and silicon source is: adding the alcohol solution of titanium source into the aqueous solution containing microporous template agent and silicon source at a rate of 0.005-0.015 mL / min, and stirring for 2-5 hours.

[0035] Preferably, the titanium source is at least one of tetraalkoxy titanium, tetraalkyl titanate and titanium tetrachloride.

[0036] Preferably, the microporous template agent is at least one of tetrapropylammonium hydroxide, tetrapropylammonium bromide and tetraethylammonium hydroxide.

[0037] Preferably, the silicon source is at least one of silicate, silicic acid, silica hydrogel and tetraethyl orthosilicate.

[0038] Preferably, the titanium-silicon molecular sieve seed is TS-1 molecular sieve seed.

[0039] Preferably, the mesoporous template agent is at least one of P123 (polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer), CTAB (hexadecyl trimethyl ammonium bromide) and n-butylamine.

[0040] Preferably, in step (3), the metal oxide is at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

[0041] Preferably, in step (4), the mixed solution containing noble metal precursor and structure promoter has a pH value of 9-12.

[0042] Preferably, the noble metal precursor is selected from at least one of chloroplatinic acid, hexaammineplatinum (IV) acid 2-hydroxyethylamine salt, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate and palladium acetate.

[0043] Preferably, the structural aid is selected from at least one of ferric nitrate, cerium nitrate, lanthanum nitrate, lanthanum sulfate, lanthanum chloride, cerium sulfate and cerium oxide.

[0044] Preferably, in step (4), the purging process is purging with a 1.5-2.5 MPa air knife.

[0045] Preferably, the calcination conditions include a temperature of 200-300℃ and a time of 4-10 hours.

[0046] Preferably, in 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.

[0047] Preferably, the reduction conditions include a catalyst temperature rise rate of 2-20℃ / min, a reduction temperature of 300-450℃, and a reduction time of 1-10h.

[0048] The third aspect of the present application provides a monolithic catalyst prepared by the above method.

[0049] The fourth aspect of the present application provides the use of the above monolithic catalyst in catalyzing the oxidation of carbon-based oxygen-containing molecular gas.

[0050] According to the technical solution of the present application, in the preparation process of the catalyst, the acid-treated regular carrier is attached with a coating slurry containing titanium silicalite molecular sieve, the titanium silicalite molecular sieve in the coating slurry can react with the exposed hydroxyl groups on the surface of the acid-treated regular carrier, and a chemical bond is formed between the coating and the regular carrier, so that the coating has high firmness and a very low powder loss rate. Moreover, the technical solution of the present application can control the coating matrix pore, so as to realize the control of the coating structure of the monolithic catalyst, promote the dispersion of active noble metal and the exposure of active phase, efficiently construct the catalytic active sites on the surface of the catalyst, increase the adsorption capacity of carbon-based oxygen-containing molecular gas and oxygen while reducing the content of noble metal catalyst, promote the adsorption and activation of oxygen, and thus improve the catalytic efficiency of the catalyst.

[0051] Compared with the prior art, the technical solution of the present application has the following advantages:

[0052] (1) The monolithic catalyst prepared by the present application has high oxygen adsorption and activation capacity, and high catalytic oxidation efficiency.

[0053] (2) The monolithic catalyst prepared by the present application has high mechanical strength and is suitable for high air speed and large gas treatment working conditions.

[0054] (3) In the monolithic catalyst of the present application, the pore structure of the coating matrix can be adjusted, and has the advantages of strong quantitative adjustment and strong adaptability to raw materials;

[0055] (4) In the monolithic catalyst of the present application, the catalyst coating and the carrier are combined by chemical bonds, and have the advantages of high firmness, strong water resistance, and being conducive to continuous long-period operation;

[0056] (5) In the monolithic catalyst of the present application, the content of the active noble metal component is low, which can greatly reduce the operating cost. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 is an SEM image of the monolithic catalyst prepared in Example 1;

[0058] Figure 2 is a TEM image of the monolithic catalyst prepared in Example 1. DETAILED DESCRIPTION

[0059] The specific embodiments of the present application are described in detail below. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0060] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The endpoints of the ranges of values and the values thereof can be combined with other endpoints to form new ranges and new values, which are also contemplated as disclosed herein.

[0061] In the present application, unless otherwise specified, the concentration of a gas "% " refers to "volume %"; "space velocity" refers to "volume space velocity"; and pressure refers to absolute pressure.

[0062] The monolithic catalyst described in the present application comprises:

[0063] a carrier, which is a regular carrier treated by acid;

[0064] a coating attached to the carrier, which contains a titanium-silicon molecular sieve and a metal oxide; and

[0065] an active component dispersed in the coating, which contains a noble metal and optionally an alloy metal.

[0066] In the monolithic catalyst, the titanium silicalite zeolite in the coating has a strong binding firmness with the regular carrier, and the coating has a low powder dropping rate. Specifically, the powder dropping rate of the coating is 1% or less, preferably 0.1-1%, and more preferably 0.1-0.5%. In the present application, the powder dropping rate is detected by ultrasonic oscillation method, and the detection conditions include: ultrasonic frequency 45 kHz, ultrasonic power 130 W, and processing time 60 min.

[0067] In the monolithic catalyst, the active component is fully 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, and more preferably 2-3 nm.

[0068] In the monolithic catalyst, the particle size of the coating can be 50-500 nm, and preferably 80-480 nm.

[0069] In the monolithic catalyst, the mesopore size of the coating can be 1-50 nm, and preferably 1.7-45 nm; the specific surface area can be 300-600 m 2 / g, and preferably 400-550 m 2 / g.

[0070] In the monolithic catalyst, the content of the coating 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, relative to 100 parts by weight of the carrier; and 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.

[0071] In the present application, the regular carrier is preferably at least one selected from the group consisting 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, and most preferably cordierite honeycomb carrier.

[0072] In the monolithic catalyst, the weight ratio of the titanium silicalite zeolite to the metal oxide in the coating can be 1:0.1-0.5, and preferably 1:0.2-0.4.

[0073] In the monolithic catalyst according to the present application, the titanium silicalite molecular sieve forming the coating can be any conventional mesoporous titanium silicalite molecular sieve. In the most preferred embodiment, the titanium silicalite molecular sieve is TS-1 molecular sieve.

[0074] In the monolithic catalyst according to the present application, in the coating, the metal oxide can be at least one selected from the group consisting of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

[0075] In the monolithic catalyst according to the present application, in the active component, the alloy metal is an optional component. In the more 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 noble metal element, alloy and 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.

[0076] In the monolithic catalyst according to the present application, in the active component, the noble metal can be at least one selected from the group consisting 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 can be 1:0.5-2, most preferably 1:1.

[0077] In the monolithic catalyst according to the present application, in the active component, the alloy metal can be at least one selected from the group consisting of Fe, La and Ce, preferably a combination of La and Ce. When the alloy metal is a combination of La and Ce, the molar ratio of La to Ce can be 1:0.5-2, most preferably 1:1.

[0078] The method for preparing the monolithic catalyst according to the present application comprises the following steps:

[0079] (1) subjecting the regular carrier to acid treatment;

[0080] (2) mixing an alcohol solution of titanium source with an aqueous solution containing microporous template agent and silicon source, aging, removing alcohol, and then mixing the obtained gel solution with titanium silicalite molecular sieve seeds and mesoporous template agent;

[0081] (3) mixing the mixed solution obtained in step (2) with metal oxide, ball milling to obtain a coating slurry;

[0082] (4) mixing the coating slurry with a mixed solution containing noble metal precursor and optional structural aid, adding the obtained mixed slurry to the acid-treated regular carrier, and then sequentially performing purging, drying, calcination and reduction.

[0083] In step (1), the acid treatment process can remove impurities contained in the shaped support and form a bare hydroxyl surface. The acid treatment process can include refluxing the shaped support with an acidic solution, then washing to neutral and drying.

[0084] 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.

[0085] Specifically, the acid in the acidic solution can be a strong inorganic acid, preferably at least one of nitric acid, sulfuric acid and hydrochloric acid, and most preferably nitric acid.

[0086] Specifically, the refluxing conditions can include a temperature of 70-90°C, preferably 80°C, and a time of 12-36 hours, preferably 24 hours.

[0087] In the method of the present application, the shaped support can be selected from at least one of cordierite honeycomb support, mullite honeycomb support, diamond honeycomb support, corundum honeycomb support, zircon corundum honeycomb support, quartz honeycomb support, nepheline honeycomb support, feldspar honeycomb support and alumina honeycomb support, preferably cordierite honeycomb support.

[0088] In step (2), the specific process of mixing the alcohol solution of the titanium source with the aqueous solution containing the microporous template agent and the silicon source is as follows: the alcohol solution of the titanium source 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.

[0089] In the present application, the titanium source can be selected from water-soluble or water-dissolvable titanium-containing compounds, generally referring to titanium dioxide (TiO2) sources. In specific embodiments, the titanium source includes but is not limited to at least one of titanium tetraalkoxide, tetraalkyl titanate and titanium tetrachloride, and most preferably n-butyl titanate.

[0090] In the present application, in the alcohol solution of the titanium source, the alcohol solvent used can be at least one of isopropyl alcohol, ethanol and n-propanol.

[0091] In the present application, the concentration of the alcohol solution of the titanium source can be 5-15 wt.%.

[0092] In the present application, the silicon source can be selected from water-soluble or water-dissolvable silicon-containing compounds, generally referring to silica (SiO2) sources. In specific embodiments, the silicon source includes but is not limited to at least one of silicate, silicic acid, silica hydrogel and tetraethyl orthosilicate, and preferably tetraethyl orthosilicate.

[0093] In the present application, the micropore templating agent can be at least one selected from the group consisting of tetrapropylammonium hydroxide, tetrapropylammonium bromide and tetraethylammonium hydroxide.

[0094] In the present application, the titanium silicalite molecular sieve seed is preferably TS-1 molecular sieve seed.

[0095] In the present application, the mesopore templating agent can be at least one selected from the group consisting of P123, CTAB and n-butylamine.

[0096] In step (2), the aging process can be carried out at room temperature, and the aging time is 2-5 hours.

[0097] In step (2), the alcohol removal process is specifically as follows: the aged mixed solution is warmed to 85-95℃ at a rate of 1-20℃ / min (preferably 5-17℃ / min), and the alcohol is removed at 85-95℃ for 10-15 hours.

[0098] In step (2), the mixing of the gel solution with the titanium silicalite molecular sieve seed and the mesopore templating agent is carried out under stirring, and the mixing conditions can include: temperature of 35-45℃, and time of 0.5-2 hours.

[0099] In step (3), the metal oxide can be at least one selected from the group consisting of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2.

[0100] In step (3), the mixing and ball milling time can be 1-5 hours, preferably 2-3 hours.

[0101] In step (4), the mixing of the coating slurry with the mixed solution containing the noble metal precursor and the structure aid is carried out under stirring, and the mixing conditions can include: temperature of 15-40℃, preferably 25℃; and time of 1-4 hours, preferably 3 hours.

[0102] In step (4), the mixed solution containing the noble metal precursor and the structure aid has a pH value of 9-12, and specifically, the pH value of the mixed solution can be, for example, 9, 10, 11 or 12.

[0103] In the present application, the noble metal in the noble metal precursor is at least one selected from the group consisting of silver, ruthenium, rhodium, palladium, osmium, iridium and platinum, and is preferably a combination of platinum and palladium. In a specific embodiment, the noble metal precursor is at least one selected from the group consisting of chloroplatinic acid, hexaammineplatinum (IV) acid 2-hydroxyethylamine salt, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate and palladium acetate.

[0104] In step (4), the structural aid is added to provide alloying metals, so that the active component in the prepared monolithic catalyst exists in the form of noble metal element, alloy and noble metal oxide. In a specific embodiment, the structural aid is selected from at least one of ferric nitrate, cerium nitrate, lanthanum nitrate, lanthanum sulfate, lanthanum chloride, cerium sulfate and cerium oxide.

[0105] In step (4), the purging process can be purging with a gas knife at 1.5-2.5 MPa.

[0106] In step (4), the drying process can be performed in a drying oven. Specifically, the temperature of the drying oven can be 80-120°C, preferably 100°C; and the drying time can be 5-24 hours, preferably 12 hours.

[0107] In step (4), the calcination conditions can include a temperature of 200-300°C and a time of 4-10 hours.

[0108] In step (4), the reducing atmosphere in the reduction process can be H2, CO, a combination of H2 and CO, a mixed atmosphere with different hydrogen concentrations, and 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, and by adjusting the reducing atmosphere, efficient control of the surface oxygen vacancies of the catalyst is achieved. Specifically, the reducing atmosphere can be, for example, 5% H2 (N2 dilution), 10% H2 (N2 dilution), 15% H2 (N2 dilution), 5% CO (N2 dilution), etc.

[0109] In step (4), the reduction conditions can include a catalyst temperature rising rate of 2-20°C / min, a reduction temperature of 300-450°C, and a reduction time of 1-10 h.

[0110] In the method of the present application, the amounts of the various reaction raw materials in steps (1) to (4) are such that, in the prepared monolithic catalyst, the content of the coating is 1-10 parts by weight, preferably 2-8 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, preferably 0.1-0.5 parts by weight.

[0111] The present application also provides a monolithic catalyst prepared by the above method. In the monolithic catalyst, the titanium silicalite in the coating reacts with the exposed hydroxyl groups on the surface of the acid-treated regular carrier to form chemical bonds, so that the coating has high firmness and a very low powder loss rate; and the active noble metal is uniformly dispersed, and the particle size of the active component is small.

[0112] The application further provides application of the monolithic catalyst in catalyzing oxidation of carbon-based oxygen-containing molecular gas.

[0113] The monolithic catalyst, the preparation method and the application thereof according to the application are further illustrated by examples. The examples are implemented on the premise of the technical scheme of the application, and detailed implementation modes and specific operation processes are given, but the protection scope of the application is not limited to the following examples.

[0114] In the following examples, the experimental methods are all conventional methods in the art unless otherwise specified. The experimental materials used in the following examples are commercially available unless otherwise specified.

[0115] Example 1

[0116] This example is used to illustrate the monolithic catalyst, the preparation method and the application thereof according to the application.

[0117] Firstly, commercially available 200cpsi, 100x100x50mm cordierite honeycomb ceramics were treated with 2mol / L nitric acid at 80℃ for 24h, washed with deionized water until the pH value was 7, and naturally air-dried for standby use.

[0118] Secondly, 3.6g of isopropyl alcohol was uniformly mixed with 0.368g of n-butyl titanate to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, 22.58g of ethyl silicate 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, and then heated to 90℃ at a heating rate of 5-6℃ / min, and 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 TS-1 crystal seeds and 0.5g of P123 at 40℃ for 1h to obtain solution 5, 5ml of 1mol / L CTAB was added to solution 5, and mixed and stirred for 2h, then 0.35g of metal oxide TiO2 was added, and mixed and ball-milled for 2h to obtain coating slurry 6.

[0119] Then, 0.5 L of a mixed solution of chloroplatinic acid and palladium chloride (molar ratio of platinum to palladium is 1:1) and 200 ml of a mixed solution of cerium nitrate and lanthanum nitrate (molar ratio of cerium to lanthanum is 1:1) at 25℃ and pH 9 were stirred for 3 h to obtain solution 7. Solution 7 was added to the coating slurry 6, and stirred for 30 min to obtain mixed slurry 8. Then, the mixed slurry 8 was added dropwise to the acid-treated cordierite honeycomb ceramics, and was blown with a 2 MPa air knife, and was treated in a 100℃ drying oven for 12 h, and was calcined at 250℃ for 6 h. Then, the whole catalyst Cat-1 was obtained by reduction at 400℃ (temperature rising rate is 10℃ / min) under an atmosphere of 10% H2 and 90% N2 for 5 h. The content of the active noble metal component is 0.15% by weight, the particle size of the active noble metal component is between 2.1-2.2 nm, the coating particle size is between 80-150 nm, the mesopore size distribution is 2-5 nm, the specific surface area is about 400 m 2 / g, and the powder loss rate of the coating is 0.2%.

[0120] The SEM and TEM images of the whole catalyst are shown in Figure 1 and Figure 2 respectively.

[0121] The catalyst was loaded in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, wherein the space velocity was 5000 h -1 , the reaction pressure was 0.1 MPa, and the reaction temperature was 265℃. The CO concentration and VOCs concentration at the outlet of the reactor were detected by using a gas chromatograph. According to the reaction results, CO≤100 ppm, VOCs≤120 ppm, the conversion rate≥99%, and the catalyst stability was 500 h (i.e. the reaction was continuously carried out for 500 h, and the catalytic activity of the catalyst did not decrease obviously).

[0122] Example 2

[0123] This example is used to illustrate the whole catalyst, the preparation method and the application thereof according to the present application.

[0124] Firstly, commercially available 200 cpsi, 100x100x50 mm cordierite honeycomb ceramics were treated with 1.5 mol / L sulfuric acid at 70℃ for 36 h, washed with deionized water until the pH value was 7, and naturally air-dried for standby use.

[0125] Secondly, 3.6g of isopropyl alcohol was mixed with 0.368g of n-butyl titanate to obtain solution 1. 27.9g of tetrapropyl ammonium hydroxide was placed in a beaker, 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 0.005ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 4 hours, and then increased to 90℃ at a rate of 10-12℃ / min, and alcohol was removed at 90℃ for 10 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 2g of commercially available TS-1 crystal seeds and 0.5g of P123 at 40℃ for 1h to obtain solution 5, 5ml of 3mol / L CTAB was added to solution 5, mixed and stirred for 2h, then 0.35g of metal oxide Al2O3 was added, and the mixture was ball milled for 2h to obtain coating slurry 6.

[0126] Then, 0.5L of 1mol / L chloroplatinic acid and palladium chloride mixed solution (molar ratio of platinum to palladium was 1:1) and 200ml of 1mol / L cerium nitrate and lanthanum nitrate mixed solution (molar ratio of cerium to lanthanum was 1:1) were stirred at 20℃ and pH 10 for 4h to obtain solution 7. Solution 7 was added to the coating slurry 6, and stirred for 30min to obtain mixed slurry 8. Then the mixed slurry 8 was added dropwise to the acid-treated cordierite honeycomb ceramic, blown with a 2.5MPa air knife, treated in a 100℃ drying oven for 12 hours, and calcined at 230℃ for 8 hours. Then it was reduced at 380℃ (heating rate was 8℃ / min) under 5% CO and 95% N2 atmosphere for 6 hours to obtain the monolithic catalyst Cat-2. The content of the active noble metal component was 0.16wt%, the particle size of the active noble metal component was between 2.3-2.5nm, the coating particle size was between 150-200nm, the mesoporous pore size distribution was 8-12nm, the specific surface area was about 380m 2 / g, and the powder loss rate of the coating was 0.2%.

[0127] The catalyst was loaded in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, the space velocity was 5000h -1 , the reaction pressure was 0.1MPa, and the reaction temperature was 275℃. The CO concentration and VOCs concentration at the outlet of the reactor were detected by gas chromatography. According to the reaction results, CO≤100ppm, VOCs≤120ppm, the conversion rate≥99%, and the stability of the catalyst was 500h (i.e. the reaction was continuously carried out for 500h, and the catalytic activity of the catalyst did not decrease obviously).

[0128] Example 3

[0129] This example is used to illustrate the monolithic catalyst and the preparation method and application thereof according to the present application.

[0130] First, commercially available 200 cpsi, 100x100x50mm cordierite honeycomb ceramics were treated with 2.5mol / L hydrochloric acid at 90℃ for 12h, washed with deionized water until the pH value was 7, and naturally air-dried for standby use.

[0131] Secondly, 3.6g of isopropyl alcohol was mixed with 0.368g of n-butyl titanate to obtain solution 1. 27.9g of tetrapropylammonium hydroxide was placed in a beaker, 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 0.015ml / min, and stirred for 3 hours to obtain mixed solution 3. The mixed solution 3 was aged at room temperature for 2 hours, and then increased to 90℃ at a rate of 14-15℃ / min, and alcohol was removed at 90℃ for 14 hours to obtain transparent gel liquid 4. The transparent gel liquid 4 was mixed with 1g of commercially available TS-1 crystal seeds and 1g of P123 at 40℃ for 1h to obtain solution 5, 5ml of 5mol / L CTAB was added to the solution 5 and mixed for 2h, then 0.35g of metal oxide ZrO2 was added and mixed ball milled for 2h to obtain coating slurry 6.

[0132] Then, 0.5L of 1mol / L chloroplatinic acid and palladium chloride mixed solution (platinum and palladium molar ratio of 1:1) and 200ml of 1mol / L cerium nitrate and lanthanum nitrate mixed solution (cerium and lanthanum molar ratio of 1:1) were stirred at 30℃ and pH 11 for 2h to obtain solution 7. Solution 7 was added to the coating slurry 6 and stirred for 30min to obtain mixed slurry 8. Then the mixed slurry 8 was added dropwise to the acid-treated cordierite honeycomb ceramics, blown with a 1.5MPa air knife, treated in a 100℃ drying oven for 12h, and calcined at 270℃ for 5h. Then it was reduced at 420℃ (heating rate of 12℃ / min) under 15%H2 and 85%N2 atmosphere for 4h to obtain the monolithic catalyst Cat-3. The content of the active noble metal component was 0.15wt%, the particle size of the active noble metal component was between 2.0-2.1nm, the coating particle size was between 50-100nm, the mesoporous pore size distribution was 3-4nm, the specific surface area was about 480m 2 / g, and the powder loss rate of the coating was 0.2%.

[0133] The catalyst was packed in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, with a space velocity of 5000h -1, the reaction pressure is 0.1 MPa, and the reaction temperature is 245°C. The CO concentration and VOCs concentration at the outlet of the reactor are detected by using a gas chromatograph. According to the reaction results, CO≤100 ppm, VOCs≤120 ppm, the conversion rate≥99%, and the stability of the catalyst is 500 h (i.e., the reaction is continuously carried out for 500 h, and the catalytic activity of the catalyst does not obviously decrease).

[0134] Example 4

[0135] This example is used to illustrate the monolithic catalyst and the preparation method and application thereof according to the present application.

[0136] Firstly, commercially available 200 cpsi, 100x100x50 mm cordierite honeycomb ceramics are taken, and are treated with 2 mol / L nitric acid at 80°C for reflux for 24 h, and are washed with deionized water until the pH value is 7, and are naturally air-dried for standby use.

[0137] Secondly, 3.6 g of isopropyl alcohol is uniformly mixed with 0.368 g of n-butyl titanate to obtain solution 1. 27.9 g of tetrapropylammonium hydroxide is placed in a beaker, 22.58 g of tetraethyl orthosilicate and 6.9 g of H2O are added, and stirring is performed for 30 min to obtain solution 2. Solution 1 is added to solution 2 at a rate of 0.008 ml / min, and stirring is performed for 3 h to obtain mixed solution 3. Mixed solution 3 is aged at room temperature for 3 h, and then is raised to 90°C at a temperature raising rate of 5-6°C / min, and is alcohol-removed at 90°C for 12 h to obtain transparent gel liquid 4. Transparent gel liquid 4 is mixed with 1 g of commercially available TS-1 crystal seeds and 0.5 g of P123 at 40°C for stirring for 1 h to obtain solution 5, 10 ml of 1 mol / L CTAB is added to solution 5, and stirring is performed for 2 h, and then 0.35 g of metal oxide TiO2 is added, and ball milling is performed for 2 h to obtain coating slurry 6.

[0138] Then, 0.6 L of a mixed solution of 1 mol / L chloroplatinic acid and palladium chloride (the molar ratio of platinum to palladium is 1.5:1) and 240 ml of a mixed solution of 1 mol / L cerium nitrate and lanthanum nitrate (the molar ratio of cerium to lanthanum is 1:1) are stirred at 25°C and pH 10 for 3 h to obtain solution 7. Solution 7 is added to the coating slurry 6, and stirring is performed for 30 min to obtain mixed slurry 8. Then, mixed slurry 8 is added dropwise to the acid-treated cordierite honeycomb ceramics, is blown with a 2 MPa air knife, is treated in a 100°C drying oven for 12 h, and is calcined at 200°C for 10 h. Then, reduction is performed at 420°C (the temperature raising rate is 8°C / min) under a 10% H2 and 90% N2 atmosphere for 6 h to obtain the monolithic catalyst Cat-4. The content of the active noble metal component is 0.18% by weight, the particle size of the active noble metal component is between 2.1-2.2 nm, the coating particle size is between 100-150 nm, the mesopore size distribution is 18-22 nm, and the specific surface area is about 400 m2 / g.2 The powder loss rate of the coating was 0.2%.

[0139] The catalyst was loaded in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, wherein the space velocity was 5000 h-1, the reaction pressure was 0.1 MPa, and the reaction temperature was 275°C. The CO concentration and VOCs concentration at the outlet of the reactor were detected by using a gas chromatograph. According to the reaction results, CO≤100 ppm, VOCs≤120 ppm, the conversion rate≥99%, and the stability of the catalyst was 500 h (i.e. the reaction was continuously carried out for 500 h, and the catalytic activity of the catalyst did not obviously decrease). -1

[0140] Example 5

[0141] This example is used to illustrate the monolithic catalyst, the preparation method and the application thereof according to the present application.

[0142] Firstly, commercially available 200 cpsi, 100x100x50 mm cordierite honeycomb ceramics were treated by refluxing with 2 mol / L nitric acid at 80°C for 24 h, washed with deionized water until the pH value was 7, and naturally air-dried for standby use.

[0143] Secondly, 3.6 g of isopropyl alcohol was uniformly mixed with 0.368 g of n-butyl titanate to obtain solution 1. 27.9 g of tetrapropylammonium hydroxide was placed in a beaker, 22.58 g of tetraethyl orthosilicate and 6.9 g of H2O were added and stirred for 30 min to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.005 ml / min, and stirred for 3 h to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 h, and then increased to 90°C at a temperature increasing rate of 5-6°C / min, and alcohol was removed at 90°C for 12 h to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 1 g of commercially available TS-1 crystal seeds and 0.5 g of P123 at 40°C for 1 h to obtain solution 5, 5 ml of 1 mol / L CTAB was added to solution 5, and mixed and stirred for 2 h, followed by adding 0.35 g of metal oxide TiO2, and mixed ball milling for 2 h to obtain coating slurry 6.

[0144] ​Then, 0.8 L of a mixed solution of chloroplatinic acid and palladium chloride (molar ratio of platinum to palladium is 1:1.5) and 250 ml of a mixed solution of cerium nitrate and lanthanum nitrate (molar ratio of cerium to lanthanum is 1:1) at a concentration of 1 mol / L were stirred at 25°C and pH 11 for 3 h to obtain solution 7. Solution 7 was added to the coating slurry 6, and stirred for 30 min to obtain mixed slurry 8. Then, the mixed slurry 8 was added dropwise to the acid-treated cordierite honeycomb ceramics, and was blown with a 2 MPa air knife, and was treated in a drying oven at 100°C for 12 h, and was calcined at 220°C for 8 h. Then, the whole catalyst Cat-5 was obtained by reduction at 380°C (temperature rising rate is 12°C / min) under an atmosphere of 10% H2 and 90% N2 for 7 h. The content of the active noble metal component is 0.21% by weight, the particle size of the active noble metal component is between 2.6-2.8 nm, the coating particle size is between 80-150 nm, the mesopore size distribution is 2-5 nm, the specific surface area is about 400 m 2 / g, and the powder loss rate of the coating is 0.2%.

[0145] The catalyst was loaded in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, the space velocity was 5000 h -1 -1, the reaction temperature was 295°C. The CO concentration and VOCs concentration at the outlet of the reactor were detected by using a gas chromatograph. According to the reaction results, CO≤100 ppm, VOCs≤120 ppm, the conversion rate≥99%, and the catalyst stability was 500 h (i.e. the reaction was continuously carried out for 500 h, and the catalytic activity of the catalyst did not decrease obviously).

[0146] Example 6

[0147] This example is used to illustrate the whole catalyst, the preparation method and the application thereof according to the present application.

[0148] Firstly, commercially available 200 cpsi cordierite honeycomb ceramics with a size of 100x100x50 mm were treated with 1 mol / L nitric acid at 80°C for 24 h, washed with deionized water until the pH value was 7, and naturally air-dried for standby use.

[0149] Secondly, 3.6g of isopropyl alcohol was mixed with 0.368g of n-butyl titanate to obtain solution 1. 27.9g of tetrapropyl ammonium hydroxide was placed in a beaker, 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 0.012ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, and then was raised to 90℃ at a temperature raising rate of 5-6℃ / min, and 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 TS-1 crystal seeds and 0.5g of P123 at 40℃ for 1h to obtain solution 5, 5ml of 1mol / L CTAB was added to solution 5, and mixed and stirred for 2h, then 0.35g of metal oxide TiO2 was added, and mixed and ball milled for 2h to obtain coating slurry 6.

[0150] Then, 1L of 1mol / L chloroplatinic acid and palladium chloride mixed solution (the molar ratio of platinum to palladium was 2:1) and 180ml of 1mol / L cerium nitrate and lanthanum nitrate mixed solution (the molar ratio of cerium to lanthanum was 1:1) were stirred at 25℃ and pH 12 for 3h to obtain solution 7. Solution 7 was added to the coating slurry 6, and stirred for 30min to obtain mixed slurry 8. Then mixed slurry 8 was added dropwise to the acid-treated cordierite honeycomb ceramic, was blown with a 2MPa air knife, was treated in a 100℃ drying oven for 12 hours, and was calcined at 250℃ for 5 hours. Then the whole catalyst Cat-6 was reduced at 360℃ (the temperature raising rate was 15℃ / min) under the atmosphere of 10% H2 and 90% N2 for 10 hours. The content of the active noble metal component was 0.24wt%, the particle size of the active noble metal component was between 2.1-2.2nm, the coating particle size was between 80-150nm, the mesoporous pore size distribution was 2-5nm, the specific surface area was about 400m2 / g, and the powder loss rate of the coating was 1%. 2 -1 / g, and the powder loss rate of the coating was 1%.

[0151] The catalyst was filled in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, wherein the space velocity was 5000h -1 -1, the reaction pressure was 0.1MPa, and the reaction temperature was 275℃. The CO concentration and VOCs concentration at the outlet of the reactor were detected by using a gas chromatograph. According to the reaction results, CO≤100ppm, VOCs≤120ppm, the conversion rate≥99%, and the catalyst stability was 450h (i.e. the reaction was continuously carried out for 450h, and the catalytic activity of the catalyst did not obviously decrease).

[0152] Example 7

[0153] This example is used to illustrate the whole catalyst, the preparation method and the application thereof according to the present application.

[0154] First, commercially available 200 cpsi, 100x100x50 mm cordierite honeycomb ceramics were treated with 2 mol / L nitric acid at 80°C for 24 h, washed with deionized water until the pH value was 7, and naturally air-dried for standby use.

[0155] Secondly, 3.6 g of isopropyl alcohol was mixed with 0.368 g of n-butyl titanate to obtain solution 1. 27.9 g of tetrapropyl ammonium hydroxide was placed in a beaker, 22.58 g of tetraethyl orthosilicate and 6.9 g of H2O were added and stirred for 30 min to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.1 ml / min, and stirred for 3 h to obtain mixed solution 3. The mixed solution 3 was aged at room temperature for 3 h, and then increased to 90°C at a rate of 5-6°C / min, and alcohol was removed at 90°C for 12 h to obtain transparent gel liquid 4. The transparent gel liquid 4 was mixed with 1 g of commercially available TS-1 crystal seeds and 0.5 g of P123 at 40°C for 1 h to obtain solution 5, 5 ml of 1 mol / L CTAB was added to the solution 5 and stirred for 2 h, then 0.35 g of metal oxide TiO2 was added and ball milled for 2 h to obtain coating slurry 6.

[0156] Then, 0.7 L of 1 mol / L chloroplatinic acid and palladium chloride mixed solution (platinum and palladium molar ratio of 1:2) and 240 ml of 1 mol / L cerium nitrate and lanthanum nitrate mixed solution (cerium and lanthanum molar ratio of 1:1) were stirred at 25°C and pH 9 for 3 h to obtain solution 7. The solution 7 was added to the coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Then the mixed slurry 8 was added dropwise to the acid-treated cordierite honeycomb ceramics, blown with a 2 MPa air knife, treated in a 100°C drying oven for 12 h, and calcined at 280°C for 4 h. Then it was reduced at 320°C (heating rate of 18°C / min) under the atmosphere of 10% H2 and 90% N2 for 9 h to obtain the monolithic catalyst Cat-7. The content of the active noble metal component was 0.16 wt%, the particle size of the active noble metal component was between 2.1-2.2 nm, the coating particle size was between 80-150 nm, the mesoporous pore size distribution was 2-5 nm, the specific surface area was about 400 m 2 / g, and the powder loss rate of the coating was 0.2%.

[0157] The catalyst was loaded in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, and the space velocity was 5000 h -1The reaction pressure is 0.1 MPa, and the reaction temperature is 320 ℃. The CO concentration and VOCs concentration at the outlet of the reactor are detected by using a gas chromatograph. According to the reaction results, CO≤100 ppm, VOCs≤120 ppm, the conversion rate≥99%, and the stability of the catalyst is 400 h (i.e., the reaction is continuously carried out for 400 h, and the catalytic activity of the catalyst does not obviously decrease).

[0158] Example 8

[0159] This example is used to illustrate the monolithic catalyst and the preparation method and application thereof according to the present application.

[0160] Firstly, commercially available 200 cpsi, 100x100x50 mm cordierite honeycomb ceramics are taken, and are treated with 2 mol / L nitric acid at 80 ℃ for reflux for 24 h, and are washed with deionized water until the pH value is 7, and are naturally dried for standby use.

[0161] Secondly, 3.6 g of isopropyl alcohol is uniformly mixed with 0.368 g of n-butyl titanate to obtain solution 1. 27.9 g of tetrapropylammonium hydroxide is placed in a beaker, 22.58 g of tetraethyl orthosilicate and 6.9 g of H2O are added, and are stirred for 30 min to obtain solution 2. Solution 1 is added to solution 2 at a rate of 0.015 ml / min, and is stirred for 3 h to obtain mixed solution 3. The mixed solution 3 is aged at room temperature for 1 h, and then is raised to 90 ℃ at a temperature raising rate of 5-6 ℃ / min, and is alcohol-removed at 90 ℃ for 12 h to obtain transparent gel liquid 4. The transparent gel liquid 4 is mixed with 1 g of commercially available TS-1 crystal seeds and 0.5 g of P123 at 40 ℃ for 1 h to obtain solution 5, 5 ml of 1 mol / L CTAB is added to the solution 5, and is mixed and stirred for 2 h, and then 0.35 g of metal oxide TiO2 is added, and is mixed and ball-milled for 2 h to obtain coating slurry 6.

[0162] Then, 0.6 L of 1 mol / L chloroplatinic acid and palladium chloride mixed solution (the molar ratio of platinum to palladium is 1:1) and 150 ml of 1 mol / L cerium nitrate and lanthanum nitrate mixed solution (the molar ratio of cerium to lanthanum is 1:1) are stirred at 25 ℃ and pH 10 for 3 h to obtain solution 7. The solution 7 is added to the coating slurry 6, and is stirred for 30 min to obtain mixed slurry 8. Then the mixed slurry 8 is added dropwise to the acid-treated cordierite honeycomb ceramics, is blown by a 2 MPa air knife, is treated in a 100 ℃ drying oven for 12 h, and is calcined at 300 ℃ for 4 h. Then it is reduced at 400 ℃ (the temperature raising rate is 10 ℃ / min) under the atmosphere of 10% H2 and 90% N2 for 5 h to obtain the monolithic catalyst Cat-8. The content of the active noble metal component is 0.14% by weight, the particle size of the active noble metal component is between 2.8-3.0 nm, the coating particle size is between 300-400 nm, the mesopore size distribution is 15-30 nm, and the specific surface area is about 200 m2 / g.2 The powder loss rate of the coating was 0.5%.

[0163] The catalyst was loaded in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, wherein the space velocity was 5000 h-1, the reaction pressure was 0.1 MPa, and the reaction temperature was 350°C. The CO concentration and VOCs concentration at the outlet of the reactor were detected by using a gas chromatograph. According to the reaction results, CO≤100 ppm, VOCs≤120 ppm, the conversion rate≥99%, and the stability of the catalyst was 420 h (i.e. the reaction was continuously carried out for 420 h, and the catalytic activity of the catalyst did not obviously decrease). -1

[0164] Example 9

[0165] This example is used to illustrate the monolithic catalyst, the preparation method and the application thereof according to the present application.

[0166] Firstly, commercially available 200 cpsi, 100x100x50 mm cordierite honeycomb ceramics were treated by refluxing with 2 mol / L nitric acid at 80°C for 24 h, washed with deionized water until the pH value was 7, and naturally air-dried for standby use.

[0167] Secondly, 3.6 g of isopropyl alcohol was uniformly mixed with 0.368 g of n-butyl titanate to obtain solution 1. 27.9 g of tetrapropylammonium hydroxide was placed in a beaker, 22.58 g of tetraethyl orthosilicate and 6.9 g of H2O were added and stirred for 30 minutes to obtain solution 2. Solution 1 was added to solution 2 at a rate of 0.01 ml / min, and stirred for 3 hours to obtain mixed solution 3. Mixed solution 3 was aged at room temperature for 3 hours, and then raised to 90°C at a temperature raising rate of 7-9°C / min, and alcohol was removed at 90°C for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 1 g of commercially available TS-1 crystal seeds and 0.5 g of P123 at 40°C for 1 h to obtain solution 5, 5 ml of 1 mol / L CTAB was added to solution 5, and mixed and stirred for 2 h, followed by adding 0.35 g of metal oxide TiO2, and mixed and ball-milled for 2 h to obtain coating slurry 6.

[0168] ​Then, 0.7 L of a mixed solution of chloroplatinic acid and palladium chloride (molar ratio of platinum to palladium is 1:1) and 220 ml of a mixed solution of cerium nitrate and lanthanum nitrate (molar ratio of cerium to lanthanum is 2:1) at 25°C and pH 10 were stirred for 3 h to obtain solution 7. Solution 7 was added to the coating slurry 6 and stirred for 30 min to obtain mixed slurry 8. Then, the mixed slurry 8 was added dropwise to the acid-treated cordierite honeycomb ceramics, blown with a 2 MPa air knife, treated in a 100°C drying oven for 12 h, and calcined at 240°C for 7 h. Then, the whole catalyst Cat-9 was reduced at 410°C (temperature rising rate is 5°C / min) under an atmosphere of 10% H2 and 90% N2 for 4 h. The content of the active noble metal component is 0.17% by weight, the particle size of the active noble metal component is between 2.6-2.7 nm, the coating particle size is between 300-500 nm, the mesopore size distribution is 10-50 nm, the specific surface area is about 300 m 2 / g, and the powder loss rate of the coating is 0.6%.

[0169] The catalyst was loaded in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO, and 1% VOCs, wherein the space velocity was 5000 h -1 , the reaction pressure was 0.1 MPa, and the reaction temperature was 300°C. The CO concentration and VOCs concentration at the outlet of the reactor were detected by using a gas chromatograph. According to the reaction results, CO≤100 ppm, VOCs≤120 ppm, the conversion rate≥99%, and the catalyst stability was 450 h (i.e., the reaction was continuously carried out for 450 h, and the catalytic activity of the catalyst did not obviously decrease).

[0170] Example 10

[0171] This example is used to illustrate the whole catalyst, the preparation method and application thereof according to the present application.

[0172] First, commercially available 200 cpsi, 100x100x50 mm cordierite honeycomb ceramics were treated with 2 mol / L nitric acid at 80°C for 24 h, washed with deionized water until the pH value was 7, and naturally air-dried for standby use.

[0173] Secondly, 3.6g of isopropyl alcohol was mixed with 0.368g of n-butyl titanate to obtain solution 1. 27.9g of tetrapropyl ammonium hydroxide was placed in a beaker, 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, and then increased to 90°C at a rate of 5-6°C / min, and alcohol was removed at 90°C for 12 hours to obtain transparent gel liquid 4. Transparent gel liquid 4 was mixed with 1g of commercially available TS-1 crystal seeds and 0.5g of P123 at 40°C for 1h to obtain solution 5, 5ml of 1mol / L CTAB was added to solution 5, and stirred for 2h, then 0.35g of metal oxide TiO2 was added, and the mixture was ball milled for 2h to obtain coating slurry 6.

[0174] Then, 0.9L of 1mol / L chloroplatinic acid and palladium chloride mixed solution (platinum and palladium molar ratio of 1:1) and 250ml of 0.5mol / L cerium nitrate and lanthanum nitrate mixed solution (cerium and lanthanum molar ratio of 1:2) were stirred at 25°C and pH 11 for 3h to obtain solution 7. Solution 7 was added to the coating slurry 6, and stirred for 30min to obtain mixed slurry 8. Then the mixed slurry 8 was added dropwise to the acid-treated cordierite honeycomb ceramic, blown with a 2MPa air knife, treated in a 100°C drying oven for 12 hours, and calcined at 260°C for 5 hours. Then it was reduced at 440°C (heating rate of 3°C / min) for 2 hours under the atmosphere of 10% H2 and 90% N2 to obtain the monolithic catalyst Cat-10. The content of the active noble metal component was 0.23wt%, the particle size of the active noble metal component was between 2.1-2.2nm, the coating particle size was between 80-150nm, the mesoporous pore size distribution was 2-5nm, the specific surface area was about 400m 2 / g, and the powder loss rate of the coating was 0.2%.

[0175] The catalyst was loaded in a fixed bed reactor, and the reaction raw gas was composed of 95% CO2, 4% CO and 1% VOCs, the space velocity was 5000h -1 , the reaction pressure was 0.1MPa, and the reaction temperature was 285°C. The CO concentration and VOCs concentration at the outlet of the reactor were detected by gas chromatography. According to the reaction results, CO≤100ppm, VOCs≤120ppm, the conversion rate≥99%, and the catalyst stability was 450h (i.e. the reaction was continuously carried out for 450h, and the catalytic activity of the catalyst did not decrease obviously).

[0176] Comparative Example 1

[0177] The monolithic catalyst prepared according to the method of Example 1 differs in that the cordierite honeycomb ceramic is not acid-treated, but the mixed slurry is directly added dropwise to the untreated cordierite honeycomb ceramic to obtain the monolithic catalyst Cat-D1. The content of the active noble metal component is 0.13% by weight, the particle size of the active noble metal component is between 3.5-4.5 nm, the coating particle size is between 80-150 nm, and the powder shedding rate of the coating is 4.9%.

[0178] The catalyst was packed into a fixed-bed reactor, and 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 280 ppm, the conversion rate was 96.8%, and the catalyst stability was 45 h.

[0179] Comparative Example 2

[0180] Based on Example 1, the difference lies in that the coating slurry is prepared according to the following process:

[0181] 50g of TS-1 molecular sieve (purchased from Shanghai Zhuoyue Chemical Technology Co., Ltd., Na type, with a micropore size distribution of 0.5-0.65nm) was mixed with 100g of deionized water and wet-milled to obtain a molecular sieve slurry. 0.5L of a 1mol / L chloroplatinic acid and palladium chloride mixed solution (platinum-palladium molar ratio 1:1) and 200ml of a 1mol / L cerium nitrate and lanthanum nitrate mixed solution (cerium-lanthanum molar ratio 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 precious metal component contains 0.14% by weight, the particle size of the active precious metal component is between 4.5-5 nm, the coating particle size is between 80-150 nm, and the powder shedding rate of the coating is 3.1%.

[0182] The catalyst was packed into a fixed-bed reactor, and 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 840 ppm, the VOC concentration was approximately 220 ppm, the conversion rate was 97.6%, and the catalyst stability was 100 h.

[0183] From the above examples and comparative examples, it can be seen that the monolithic catalyst prepared by the present application has better catalytic effect in the process of catalytic oxidation of carbon-based oxygen-containing molecular gas, and the catalyst stability is obviously better, which is suitable for continuous long-period operation.

[0184] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as the disclosed content of the present application, and all fall within the protection scope of the present application.

Claims

1. A monolithic catalyst characterized by, The integrated catalyst comprises: a carrier, which is an acid-treated regular carrier; a coating layer attached to the carrier, the coating layer containing mesoporous titanium-silicon molecular sieve and metal oxide; and an active component dispersed in the coating layer, the active component containing noble metal and a combination of La and Ce, the molar ratio of the noble metal to the combination of La and Ce being 1:0.1-0.3; the powder loss rate of the coating layer being 1% or less; and the particle size of the active component being 2-3 nm. the noble metal being a combination of platinum and palladium; The particle size of the coating is 50-500 nm, the mesoporous channel size of the coating is 1-50 nm, and the specific surface area is 300-600 m 2 / g.

2. The monolithic catalyst according to claim 1, characterized in that the metal oxide being selected from at least one of TiO2, Al2O3, La2O3, CeO2, MgO and ZrO2; 3. The monolithic catalyst according to claim 1 or 2, characterized in that the powder loss rate of the coating layer being 0.1-1%.

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

5. The monolithic catalyst according to claim 1 or 2, characterized in that The regular carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zircon corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier and alumina honeycomb carrier.

6. The monolithic catalyst according to claim 1 or 2, characterized in that In the coating layer, the weight ratio of the mesoporous titanium-silicon molecular sieve to the metal oxide is 1:0.1-0.

5.

7. A process for the preparation of the monolithic catalyst according to any one of claims 1 to 6, characterized in that, The mesoporous titanium-silicon molecular sieve is TS-1 molecular sieve. The method comprises the following steps: (1) acid treatment of a regular carrier; (2) mixing of an alcohol solution of a titanium source with an aqueous solution containing micropore template agent and silicon source, aging, alcohol removal, then mixing of the obtained gel solution with titanium-silicon molecular sieve seeds and mesoporous template agent; (3) mixing of the mixed solution obtained in step (2) with metal oxide, ball milling to obtain coating slurry; (4) mixing of the coating slurry with a mixed solution containing noble metal precursor and structure aid, adding of the obtained mixed slurry to the acid-treated regular carrier, then sequentially performing purging, drying, calcination and reduction; 8. The method of claim 7, wherein, the structure aid being selected from cerium nitrate, lanthanum nitrate, lanthanum sulfate, lanthanum chloride, cerium sulfate and cerium sesquioxide.

9. The method of claim 8, wherein, In step (1), the acid treatment process comprises: reflux treatment of the regular carrier with an acidic solution, then washing to neutral and drying.

10. The method of claim 8, wherein, The concentration of the acidic solution is 1-3 mol / L.

11. The method of claim 8, wherein, The acid in the acidic solution is at least one of nitric acid, sulfuric acid and hydrochloric acid.

12. The method of claim 7, wherein, The reflux treatment conditions include: temperature of 70-90°C and time of 12-36 hours.

13. The method of claim 7 or 12, wherein, In step (2), the specific process of mixing the alcohol solution of the titanium source with the aqueous solution containing micropore template agent and silicon source is: the alcohol solution of the titanium source is added to the aqueous solution containing micropore template agent and silicon source at a rate of 0.005-0.015 mL / min, and the mixture is stirred for 2-5 hours.

14. The method of claim 7 or 12, wherein, The titanium source is selected from at least one of titanium tetraalkoxide, titanium acid tetraalkyl ester and titanium tetrachloride.

15. The method of claim 7 or 12, wherein, The micropore template agent is selected from at least one of tetrapropylammonium hydroxide, tetrapropylammonium bromide and tetraethylammonium hydroxide.

16. The method of claim 7 or 12, wherein, The silicon source is selected from at least one of silicate, silicic acid, silica hydrogel and tetraethyl orthosilicate. The titanium-silicon molecular sieve seeds are TS-1 molecular sieve seeds.

17. The method of claim 7 or 12, wherein, The mesoporous template agent is selected from at least one of P123, CTAB and n-butylamine.

18. The method of claim 7, wherein, In step (4), the pH of the mixed solution containing the noble metal precursor and the structural aid is 9-12.

19. The method of claim 7 or 18, wherein, The noble metal precursor is selected from chloroplatinic acid, 2-hydroxyethylamine salt of platinum(IV) hydroxyacetate, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate and palladium acetate.

20. The method of claim 7 or 18, wherein, In step (4), the purging process is performed using a 1.5-2.5 MPa air knife; and / or, The calcination conditions include: a temperature of 200-300℃ and a time of 4-10 hours; and / or, In 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; and / or, 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.

21. A monolithic catalyst prepared by the method of any one of claims 7-20.

22. The use of the monolithic catalyst according to any one of claims 1-6 and 21 in the catalytic oxidation of carbon-based oxygen-containing molecular gases.

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