Sulfur-tolerant CO oxidation catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of nano catalytic materials, and discloses a method for preparing a sulfur-tolerant CO oxidation catalyst, which comprises the following steps: (1) in the presence of carrier gas, contacting a second metal source with a to-be-plated base material to carry out first contact reaction to obtain a material I; (2) carrying out second contact reaction on a hydrazine reducing agent and the material I to obtain a material II; and (3) carrying out third contact reaction on the material II and a platinum source to obtain the sulfur-tolerant CO oxidation catalyst. The sulfur-tolerant CO oxidation catalyst prepared by the method provided by the invention is high in metal additive dispersity, high in catalytic conversion rate, low in activation temperature and simple in preparation method, and meanwhile, the sulfur-tolerant CO oxidation catalyst can show excellent catalytic stability in a sulfur-containing atmosphere.

Description

Technical Field

[0001] The present invention relates to the technical field of nano-catalytic materials, and in particular to a sulfur-resistant CO oxidation catalyst and a preparation method and application thereof. Background Art

[0002] Carbon monoxide (CO) is a colorless, odorless, toxic gas that has a strong binding force with hemoglobin. At higher concentrations, it can cause varying degrees of poisoning symptoms in people, harming the brain, heart, liver, kidneys, lungs and other tissues, and even causing electric shock-like death. The minimum lethal concentration for humans to inhale is 5000ppm. CO mainly comes from the incomplete combustion or partial oxidation of coal, gasoline and natural gas. Among them, industrial furnaces and civilian boilers, stoves, as well as internal combustion engines and automobile exhaust are the main sources of carbon monoxide pollution. With the increasingly stringent environmental protection requirements, the country has successively imposed strict restrictions on the CO concentration in the exhaust gas of chemical production equipment. Some regions have issued relevant standards to clarify that the maximum allowable emission of CO is 200mg / m 3 Therefore, controlling the concentration of carbon monoxide in the atmosphere is of great significance to human survival, health and environmental protection.

[0003] In some chemical production processes, when the CO concentration in industrial waste gas is >5vol%, the direct discharge of waste gas is not only a waste of resources, but also causes serious environmental pollution. Therefore, deep cold separation, solvent recovery or solid adsorption separation are usually used to purify, separate and purify CO. The CO content in the purified gas is very low and can be directly discharged in compliance with the standards. When the CO concentration in the tail gas is low (<20000ppm) (such as the analytical gas of the low-temperature methanol washing device used in the removal of acidic gas in the coal gasification unit), the recovery cost for this type of tail gas is relatively high. In order to meet the emission requirements, adsorption, photocatalysis, low-temperature plasma conversion, combustion and other methods are usually used to remove CO in it to meet the emission requirements. The catalytic oxidation method is based on the combustion method to introduce a high-efficiency catalyst to remove CO in it, which can reduce the temperature of the combustion process, has the advantages of simple process and high removal efficiency, and therefore has received widespread attention.

[0004] In terms of the research and development of high-efficiency catalysts, domestic and foreign scholars have begun research in the 1970s and have formed patents. Currently, there are three main types of catalysts used for CO catalytic oxidation: non-precious metal oxide type, perovskite oxide type and precious metal catalyst.

[0005] Among them, the non-precious metal oxide catalyst used for low-temperature oxidation of CO is mainly Hopcalite, which is a composite oxide catalyst with CuO-MnOx as the main component. This catalyst is a carrier-free catalyst that can effectively remove CO at room temperature. The lattice oxygen on the catalyst surface directly participates in the reaction and reacts with CO molecules that are preferentially adsorbed on the catalyst surface and activated. The lattice oxygen vacancies caused by the reaction are supplemented by oxygen in the air adsorbed on the catalyst surface and becoming lattice oxygen. The advantage of this catalyst is low cost, and the disadvantage is poor moisture and sulfur resistance and easy deactivation.

[0006] Among them, the non-precious metal oxide cobalt oxide also has high low-temperature catalytic oxidation activity for CO. Usually, cobalt nitrate is used as a precursor and sodium hydroxide is used as a precipitant. However, sodium dodecyl sulfate needs to be used as a surfactant during the preparation process to obtain high low-temperature activity. Moreover, the minimum temperature of the cobalt oxide catalyst prepared by precipitation oxidation method for CO catalytic oxidation is 98°C, and hydrogen peroxide needs to be added as an oxidant during the preparation process.

[0007] There are also many reports on perovskite oxide catalysts for CO catalytic oxidation reactions. The perovskite rare earth composite oxide disclosed in CN1058357A is directly loaded on a carrier with mullite as the main phase. When the CO concentration is 1% and the space velocity is 60000h -1 Under the conditions of , when the reaction temperature is 250 ° C, the CO conversion rate reaches 99%. It can be seen that perovskite oxides generally require a higher reaction temperature for CO catalytic oxidation.

[0008] However, compared with non-precious metal catalysts, precious metal catalysts such as gold and palladium have better activity and stability, but are expensive. In recent years, people have begun to pay attention to the synergistic effect between precious metals and certain transition metals to improve catalyst performance and reduce catalyst costs. However, the active components loaded on such catalysts are unevenly distributed, resulting in low activity and unstable performance, which limits their application areas.

[0009] The Pd-Ag / CeO2-ZrO2-Y2O3 catalyst disclosed in CN105312064A has a CO removal rate of 95% at 140°C, but can only be used under low CO concentration conditions (200ppm), and the preparation conditions are complicated and there are many types of elements, which limits the application of the catalyst under industrial conditions.

[0010] The flower-ball-shaped cerium oxide-loaded gold nanoparticle catalyst disclosed in CN104857957A has a CO removal efficiency of 99% within the range of 25-60°C, but its gold loading is 1%-4%, and the carrier is in the shape of a micron-level flower ball. The active component is gold nanoparticles. After the reaction, the gold nanoparticles are easy to agglomerate, resulting in a decrease in activity and a shortened service life, which also limits its application.

[0011] At present, there are many studies on the catalytic oxidation removal of CO. However, due to the influence of the previous process, the CO-containing waste gas of many chemical plants usually contains low concentrations of sulfides (<50ppm, including H2S, COS, etc.). The presence of sulfides will quickly deactivate the precious metal catalyst, making the catalytic removal process unable to proceed smoothly.

[0012] Therefore, developing precious metal catalysts that have low activation temperature, good low-temperature activity, good sulfur resistance, simple preparation method, and high stability has become an important development direction for catalysts. Summary of the invention

[0013] The purpose of the present invention is to overcome the problems of the prior art in that the catalyst for CO catalytic oxidation has a high activation temperature, poor stability, a complex preparation process, and poor sulfur resistance.

[0014] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a sulfur-resistant CO oxidation catalyst, the method comprising:

[0015] (1) in the presence of a carrier gas, contacting a second metal source with a base material to be plated to perform a first contact reaction to obtain material I; the second metal source contains at least one element selected from the group consisting of iron, nickel, cobalt, and copper; the base material to be plated is selected from at least one of a nano-Al2O3 carrier, nano-SiO2, nano-TiO2, and a carbon nanotube, and the volume average diameter of the base material to be plated is 10 nm to 30 nm;

[0016] (2) subjecting the hydrazine reducing agent to a second contact reaction with the material I to obtain the material II;

[0017] (3) subjecting the material II to a third contact reaction with a platinum source to obtain a sulfur-resistant CO oxidation catalyst;

[0018] The reaction conditions are controlled so that in the sulfur-resistant CO oxidation catalyst, the content of the platinum element is 0.1-0.5 wt% by weight and the content of the second metal element is 1-5 wt% by weight.

[0019] The second aspect of the present invention provides a sulfur-resistant CO oxidation catalyst prepared by the method described in the first aspect.

[0020] The third aspect of the present invention provides the use of the sulfur-resistant CO oxidation catalyst described in the second aspect in removing carbon monoxide from exhaust gas.

[0021] The sulfur-resistant CO oxidation catalyst provided by the present invention exhibits excellent catalytic activity in the carbon monoxide oxidation reaction, has a low activation temperature, and can also exhibit excellent catalytic stability in a sulfur-containing atmosphere.

[0022] The present invention realizes precise control of the catalyst at the nanoscale through the atomic layer deposition technology, forms an inert deposition layer around the active metal, prevents particle agglomeration during the reaction process, and thus can obtain a sulfur-resistant CO oxidation catalyst with high metal additive dispersion, more stable catalyst structure, low activation temperature, high stability, good sulfur resistance, good low-temperature activity, and high catalytic conversion rate during CO removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of a preferred sulfur-resistant CO oxidation catalyst b1 provided by the present invention;

[0024] Figure 2 This is a curve showing the change in CO conversion rate of a preferred sulfur-resistant CO oxidation catalyst b1 provided by the present invention.

[0025] Description of Reference Numerals

[0026] Deposition 1: First contact reaction Reduction: Second contact reaction

[0027] Deposition 2: Third Contact Reaction DETAILED DESCRIPTION

[0028] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0029] As mentioned above, the first aspect of the present invention provides a method for preparing a sulfur-resistant CO oxidation catalyst, the method comprising:

[0030] (1) in the presence of a carrier gas, contacting a second metal source with a base material to be plated to perform a first contact reaction to obtain material I; the second metal source contains at least one element selected from the group consisting of iron, nickel, cobalt, and copper; the base material to be plated is selected from at least one of a nano-Al2O3 carrier, nano-SiO2, nano-TiO2, and a carbon nanotube, and the volume average diameter of the base material to be plated is 10 nm to 30 nm;

[0031] (2) subjecting the hydrazine reducing agent to a second contact reaction with the material I to obtain the material II;

[0032] (3) subjecting the material II to a third contact reaction with a platinum source to obtain a sulfur-resistant CO oxidation catalyst;

[0033] The reaction conditions are controlled so that in the sulfur-resistant CO oxidation catalyst, the content of the platinum element is 0.1-0.5 wt% by weight and the content of the second metal element is 1-5 wt% by weight.

[0034] It should be noted that, in the present invention, the weight content of the second metal element is: the total weight content of iron, nickel, cobalt and copper in the sulfur-resistant CO oxidation catalyst.

[0035] The inventors have found that the sulfur-resistant CO oxidation catalyst prepared under this preferred condition can enhance the interaction between the second metal and the surface of the base material to be plated, and is not easy to fall off during the CO removal reaction; and platinum and the second metal form an interface alloy, which can give full play to the electronic auxiliary effect of the second metal, which is beneficial to the adsorption and conversion of CO, thereby improving the catalytic activity.

[0036] Preferably, the second metal source is selected from at least one of Fe(C5H5)2, (C5H5)2Ni, bis(N,N'-di-iso-propylacetamidine)cobalt, copper(II)bis(dimethylamino-2-propoxy), and copper acetylacetonate.

[0037] Preferably, the volume ratio of the second metal source to the hydrazine reducing agent is 120-200:1.

[0038] It should be noted that, in the present invention, the volume ratio of the second metal source to the hydrazine reducing agent refers to the ratio of the total volume of the second metal source introduced in the first contact reaction to the total volume of the hydrazine reducing agent introduced in the second contact reaction.

[0039] Preferably, in step (1), the operation of the first contact reaction includes: using the second metal source to perform 180-220 times of coating treatment I on the base material to be plated.

[0040] Preferably, in each of the coating treatments I, the volume flow rate of the second metal source is independently 70-180 sccm, and the introduction time of the second metal source is independently 20-50 s for every 10 g of the base material to be plated.

[0041] Preferably, the method further comprises: in step (2), before carrying out the second contact reaction, firstly using an inert gas to purge the material I, and then applying it to the second contact reaction.

[0042] Preferably, the method further comprises: in step (2), after subjecting the material I to the second contact reaction with the hydrazine reducing agent, flushing II with an inert gas to obtain the material II.

[0043] According to a preferred embodiment, the purge I and purge II conditions independently meet at least: a temperature of 30-70°C and a time of 10-200s; and

[0044] The volume flow rate of the inert gas is 10-250 sccm for every 10 g of the substrate to be plated. The inventors found that under this preferred condition, the catalytic sulfur resistance of the sulfur-resistant CO oxidation catalyst obtained is better.

[0045] More preferably, the inert gas is argon and / or helium.

[0046] Preferably, the method of the present invention further comprises: in step (3), preheating the hydrazine reducing agent to 30-70° C. before carrying out the second contact reaction.

[0047] Preferably, in step (3), the platinum source is trimethyl(methylcyclopentadienyl)platinum(IV) and / or dimethyl(1,5-cyclooctadiene)platinum.

[0048] Preferably, in step (3), the operation of the third contact reaction includes: using the platinum source to perform 30-50 times of coating treatment II on the material II.

[0049] More preferably, in each of the coating treatments II, the volume flow rate of the platinum source is independently 70-180 sccm, and the introduction time of the platinum source is independently 3-20 s for every 10 g of the base material to be plated.

[0050] Preferably, in step (1), the conditions of the first contact reaction at least meet the following conditions: temperature of 150-300° C. and pressure of 80-200 Pa.

[0051] Preferably, in step (2), the conditions of the second contact reaction at least meet the following conditions: temperature of 120-350° C., pressure of 80-200 Pa, and time of 80-200 s.

[0052] Preferably, in step (2), the structural formula of the hydrazine reducing agent is R1R2N-NR3R4, wherein R1, R2, R3 and R4 are each independently selected from hydrogen and a C1-C5 alkyl group.

[0053] More preferably, the hydrazine reducing agent is at least one selected from methylhydrazine, ethylhydrazine, propylhydrazine, tert-butylhydrazine and anhydrous hydrazine.

[0054] Preferably, the volume flow rate of the hydrazine reducing agent is 70-130 sccm; and the introduction time of the hydrazine reducing agent is 25-55 s for every 10 g of the base material to be plated.

[0055] Preferably, in step (3), the conditions of the third contact reaction at least meet the following conditions: temperature of 150-250° C. and pressure of 80-200 Pa.

[0056] According to a preferred embodiment, the method of the present invention is carried out in a reaction chamber connected to at least one ALD pulse valve; and in the presence of a carrier gas, the platinum source, the second metal source, and the hydrazine reducing agent are introduced into the reaction chamber through the pulse valve.

[0057] Preferably, the method of the present invention further comprises: preheating the platinum source and / or the second metal source to 140-180° C. before introducing them into the reaction chamber.

[0058] According to a preferred embodiment, the working temperature of the raw material transport pipeline and the ALD pulse valve in the present invention is 180-200°C, and the pressure is 10-200Pa.

[0059] According to a preferred embodiment, the method of the present invention also includes: placing the base material to be plated on a quartz plate in a reaction chamber, and after completing the third contact reaction, calcining the obtained product in a muffle furnace under an air atmosphere of 445-455°C for 3.5-4.5h, and forming it into a sphere with an average diameter of 3-5mm by a ball rolling machine to obtain the sulfur-resistant CO oxidation catalyst.

[0060] It should be noted that the present invention has no specific requirements for the ball rolling machine, and conventional models in the art can be used, as long as the average diameter of the spheres meets the requirements of the present invention.

[0061] As mentioned above, the second aspect of the present invention provides a sulfur-resistant CO oxidation catalyst prepared by the method described in the first aspect.

[0062] As mentioned above, the third aspect of the present invention provides the use of the sulfur-resistant CO oxidation catalyst described in the second aspect in removing carbon monoxide from exhaust gas.

[0063] In the present invention, unless otherwise specified, the normal temperature or room temperature involved in the following examples is 25±3°C.

[0064] The present invention is described in detail below by way of examples. Unless otherwise specified, the raw materials used are all common commercially available products.

[0065] Base material I to be plated: nano-Al2O3 carrier with a volume average diameter of 20nm;

[0066] Base material II to be plated: nano-SiO2, with a volume average diameter of 15nm;

[0067] Base material III to be plated: nano-Al2O3 carrier with a volume average diameter of 20um;

[0068] Platinum source I: trimethyl(methylcyclopentadienyl)platinum(IV), purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No. 94442-22-5;

[0069] Platinum source II: dimethyl (1,5-cyclooctadiene) platinum, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No. 12266-92-1;

[0070] The second metal source I: ferrocene (Fe(C5H5)2), purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No. 102-54-5;

[0071] The second metal source II is nickelocene ((C5H5)2Ni), purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No. 1271-28-9;

[0072] The second metal source III is cobalt (III) acetylacetonate, purchased from Shanghai MacLean Biochemical Technology Co., Ltd., CAS No. 21679-46-9;

[0073] The second metal source IV is zinc acetylacetonate, purchased from Shanghai MacLean Biochemical Technology Co., Ltd., CAS No. 14024-63-6;

[0074] Hydrazine reducing agent: hydrazine (anhydrous) (H4N2), purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No. 302-01-2;

[0075] Modifier: xylene, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No. 1330-20-7;

[0076] Carrier gas: nitrogen;

[0077] Inert gas: Argon.

[0078] Rolling ball machine: Model ZLJ-800, disc diameter 80cm, disc edge height 120cm;

[0079] Gas chromatograph: Model GC-7890A, purchased from Agilent Technologies Shanghai Branch.

[0080] Unless otherwise specified, the operating temperature of the raw material transport pipeline and the ALD pulse valve in the following examples is 180°C and the pressure is 10Pa;

[0081] The conditions of the purge I, purge II, purge III and purge IV are: temperature of 50° C. and time of 100 s.

[0082] Example 1

[0083] This example is used to illustrate a preferred method for preparing a sulfur-resistant CO oxidation catalyst provided by the present invention, which specifically includes the following steps:

[0084] (1) 10 g of the base material to be plated is placed on a quartz plate in a reaction chamber, the second metal source is preheated to 150° C., the ALD pulse valve of the second metal source is opened, the volume flow rate of the second metal source is set, and the introduction time is shown in Table 1. The second metal source is introduced into the quartz plate in the reaction chamber with a carrier gas, and the temperature and pressure are shown in Table 1. The coating treatment I is carried out on the surface of the base material to be plated, and the coating treatment I is repeated 200 times to complete the first contact reaction and obtain material I;

[0085] (2) using an inert gas to purge the material I for I; then opening the ALD pulse valve of the hydrazine reducing agent, setting the volume flow rate, introduction time, temperature and pressure of the hydrazine reducing agent as shown in Table 1, and subjecting the hydrazine reducing agent preheated to 70° C. to a second contact reaction with the purged material I, the second contact reaction time being shown in Table 1, and then using an inert gas to purge II to obtain material II;

[0086] (3) Preheating the platinum source to 150° C., opening the ALD pulse valve of the platinum source, setting the volume flow rate, introduction time, temperature and pressure of the platinum source as shown in Table 1, using a carrier gas to introduce the platinum source onto the quartz plate in the reaction chamber and perform coating treatment II on the surface of material II, repeating coating treatment II 40 times, completing the third contact reaction, and obtaining a sulfur-resistant CO oxidation catalyst, named b1;

[0087] The element contents in the sulfur-resistant CO oxidation catalyst are shown in Table 2;

[0088] Figure 1 The schematic diagram of the structure of the sulfur-resistant CO oxidation catalyst b1 is shown. Figure 1 In the process, deposition 1 (first contact reaction) is first performed on the base material to be plated to deposit the second metal to obtain material I; then the second metal is reduced by a hydrazine reducing agent (second contact reaction) to obtain material II; finally, deposition 2 (third contact reaction) is performed to deposit metal platinum to obtain a sulfur-resistant CO oxidation catalyst.

[0089] Example 2

[0090] This example is carried out in a similar manner to Example 1, except that: the base material II to be plated is used instead of the base material I to be plated for the first contact reaction, the platinum source used is the platinum source II, the second metal source used is the second metal source II, and the condition parameters are changed, see Table 1 for details, to obtain the sulfur-resistant CO oxidation catalyst, named b2;

[0091] The element contents in the sulfur-resistant CO oxidation catalyst are shown in Table 2.

[0092] Example 3

[0093] This example is carried out in a similar manner to Example 1, except that: in step (1), the second metal source used is the second metal source III, and the sulfur-resistant CO oxidation catalyst is obtained, named b3;

[0094] The element contents in the sulfur-resistant CO oxidation catalyst are shown in Table 2.

[0095] Example 4

[0096] This example is carried out in a similar manner to Example 1, except that: in step (2), the introduction time of the hydrazine reducing agent is reduced so that the volume ratio of the second metal source to the hydrazine reducing agent is 300:1, and the sulfur-resistant CO oxidation catalyst is obtained, which is named b4;

[0097] The element contents in the sulfur-resistant CO oxidation catalyst are shown in Table 2.

[0098] Comparative Example 1

[0099] In this comparative example, a conventional equal volume impregnation method is used to directly load a platinum precursor (chloroplatinic acid solution) on a carrier to obtain a CO oxidation catalyst. The specific operation includes:

[0100] SS1. Weigh 0.1 g of chloroplatinic acid (H2PtCl6) and add it to a 1 L constant volume flask. Add deionized water to fully dissolve it, then make the volume to 1 L. After the solution is clarified uniformly, let it stand to obtain a chloroplatinic acid solution.

[0101] SS2, placing the nano-Al2O3 carrier in a muffle furnace, calcining at 500°C in an air atmosphere for 4 hours, with a heating rate of 3°C / min. After the calcination is completed, cooling to room temperature to obtain the treated nano-Al2O3 carrier, which is sealed and stored;

[0102] SS3, saturated water absorption rate determination: weigh 1g (M0) of the treated nano-Al2O3 carrier and add it to a 5mL measuring cylinder. After knocking it on a flat surface, read the dense volume as 1mL (V1). After adding 2mL (V2) of water, stir it thoroughly and let it stand for 12h. Read the volume of the mixed solution as 2.3mL (V3);

[0103] According to the formula: carrier saturated water absorption rate ω=((V 1+ V2)-V3) / M0; (mL / g)

[0104] The calculated saturated water absorption rate of the nano-Al2O3 carrier is 0.7 mL / g.

[0105] SS4, weigh 1.52g of the chloroplatinic acid solution prepared in step (1), add it together with 1.16g of ferric nitrate (Fe(NO3)·9H2O) into a 50mL beaker, add 6.3mL of deionized water, stir and dissolve, then add 10g of the treated nano-Al2O3 carrier, stir for 0.5h at room temperature to obtain a slurry mixture. Use a sealing film to seal the beaker containing the slurry mixture. Place it in a cool and dry place and let it stand for 12h to obtain a slurry catalyst.

[0106] SS5. The slurry catalyst was placed in a crucible, and then placed in a muffle furnace in an air atmosphere, heated from room temperature to 500°C at a heating rate of 2°C / min, and calcined at 500°C for 4 hours. After calcination, it was cooled to room temperature, taken out and sealed for storage to obtain a CO oxidation catalyst, named DP1; the element content in the catalyst is shown in Table 2.

[0107] Comparative Example 2

[0108] This comparative example is carried out in a similar manner to Example 1, except that: the base material III to be plated is used for the first contact reaction to obtain a CO oxidation catalyst, named DP2; the element contents in the catalyst are shown in Table 2.

[0109] Comparative Example 3

[0110] This comparative example was carried out using a method similar to that of Example 1, except that in step (1), the second metal source used was second metal source IV, and a CO oxidation catalyst was obtained, named DP3; the element contents in the catalyst are shown in Table 2.

[0111] Test Example 1

[0112] The catalyst prepared in the above example was placed in a fixed bed microreactor (the inner diameter of the reaction tube was 6 mm), and the temperature was raised to 250° C. at a heating rate of 5° C. / min. The catalyst was then subjected to a catalytic oxidation reaction with the feed gas for 200 h, wherein:

[0113] The composition of the reaction raw gas is: 0.6 vol% CO (C0), 0.005 vol% H2S, 5 vol% O2 and 94.395 vol% CO2, and the reaction space velocity is 10000h -1 .

[0114] The concentration of CO at the reactor outlet at time t was measured by gas chromatography (C t ), and the CO conversion rate is calculated according to the following formula: CO conversion rate / % = (C 0- C t ) / C0*100%;

[0115] In addition, the activation temperature T 50 That is, the temperature corresponding to when the CO conversion rate is 50%;

[0116] T 90 That is, the temperature corresponding to when the CO conversion rate is 90%;

[0117] Monitor the change of CO conversion rate of product b1 over time within 200 hours. See the results in Figure 2 ;

[0118] The CO conversion rate after 200 h of reaction was calculated for the catalyst prepared in the above example. The results are shown in Table 3.

[0119] Table 1

[0120]

[0121] Table 2

[0122]

[0123] Table 3

[0124]

[0125]

[0126] It can be seen from the reaction results that the present invention realizes precise control of the catalyst at the nanoscale through the atomic layer deposition technology, can enhance the interaction between the second metal and the carrier surface, form an interface alloy with the active metal and the second metal, give full play to the electronic auxiliary effect of the second metal, which is beneficial to the adsorption and conversion of CO, and is a sulfur-resistant CO oxidation catalyst with low activation temperature, good low-temperature activity, high stability and high catalytic conversion rate.

[0127] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a sulfur-resistant CO oxidation catalyst, characterized in that: The method includes: (1) in the presence of a carrier gas, contacting a second metal source with a base material to be plated to perform a first contact reaction to obtain material I; the second metal source contains at least one element selected from the group consisting of iron, nickel, cobalt, and copper; the base material to be plated is selected from at least one of a nano-Al2O3 carrier, nano-SiO2, nano-TiO2, and a carbon nanotube, and the volume average diameter of the base material to be plated is 10 nm to 30 nm; (2) subjecting the hydrazine reducing agent to a second contact reaction with the material I to obtain the material II; (3) subjecting the material II to a third contact reaction with a platinum source to obtain a sulfur-resistant CO oxidation catalyst; The reaction conditions are controlled so that in the sulfur-resistant CO oxidation catalyst, the content of the platinum element is 0.1-0.5 wt% by weight and the content of the second metal element is 1-5 wt% by weight.

2. The method according to claim 1, wherein: The second metal source is selected from at least one of Fe(C5H5)2, (C5H5)2Ni, bis(N,N'-di-iso-propylacetamidine)cobalt, copper(II)bis(dimethylamino-2-propoxy), and copper acetylacetonate.

3. The method according to claim 1 or 2, wherein: The volume ratio of the second metal source to the hydrazine reducing agent is 120-200:

1.

4. The method according to any one of claims 1 to 3, wherein: In step (1), the operation of the first contact reaction includes: using the second metal source to perform 180-220 times of coating treatment I on the base material to be plated; Preferably, in each of the coating treatments I, the volume flow rate of the second metal source is independently 70-180 sccm, and the introduction time of the second metal source is independently 20-50 s for every 10 g of the base material to be plated.

5. The method according to any one of claims 1 to 4, wherein: In step (3), the operation of the third contact reaction includes: using the platinum source to perform 30-50 times of coating treatment II on the material II; Preferably, in each of the coating treatments II, the volume flow rate of the platinum source is independently 70-180 sccm, and the introduction time of the platinum source is independently 3-20 s for every 10 g of the base material to be plated.

6. The method according to any one of claims 1 to 5, wherein: In step (1), the conditions of the first contact reaction at least meet the following conditions: temperature of 150-300° C. and pressure of 80-200 Pa.

7. The method according to any one of claims 1 to 6, wherein: In step (2), the conditions of the second contact reaction at least meet the following conditions: temperature of 120-350° C., pressure of 80-200 Pa, and time of 80-200 s.

8. The method according to any one of claims 1 to 7, wherein: In step (2), the structural formula of the hydrazine reducing agent is R1R2N-NR3R4, wherein R1, R2, R3 and R4 are each independently selected from hydrogen and a C1-C5 alkyl group; Preferably, the hydrazine reducing agent is selected from at least one of methylhydrazine, ethylhydrazine, propylhydrazine, tert-butylhydrazine and anhydrous hydrazine.

9. The method according to any one of claims 1 to 8, wherein: In step (3), the conditions of the third contact reaction at least meet the following requirements: temperature of 150-250° C. and pressure of 80-200 Pa.

10. A sulfur-resistant CO oxidation catalyst prepared by the method according to any one of claims 1 to 9.

11. Use of the sulfur-resistant CO oxidation catalyst according to claim 10 in removing carbon monoxide from exhaust gas.

Images