A sulfur-resistant noble metal-based CO oxidation catalyst and its preparation method and application

Abstract

This invention relates to the field of carbon monoxide oxidation catalyst technology, and discloses a sulfur-resistant noble metal-based CO oxidation catalyst, its preparation method, and its application. The catalyst preparation method includes: impregnating a support in an aqueous solution containing a noble metal precursor and an auxiliary precursor, followed by drying and calcination to obtain a catalyst matrix; pre-reducing the catalyst matrix in a hydrogen-containing atmosphere to obtain a catalyst intermediate; and inducing activation of the catalyst intermediate in an atmosphere containing CO and H2S. The support is at least one selected from titanium dioxide, cerium dioxide, alumina, and zirconium dioxide, and the metal element in the auxiliary precursor is at least one selected from Fe, Co, and Ni. The catalyst prepared according to the method of this invention can achieve a highly selective oxidation process of H2S species, inhibit the adsorption of S species and the formation of sulfate, and realize a high-conversion oxidation reaction of carbon monoxide in the presence of H2S.

Description

Technical Field

[0001] This invention relates to the field of carbon monoxide oxidation catalyst technology, specifically to a sulfur-resistant noble metal-based CO oxidation catalyst, its preparation method, and its application. Background Technology

[0002] Carbon monoxide (CO) is a colorless, odorless, and toxic gas, generally originating from the incomplete combustion or partial oxidation of coal, gasoline, and natural gas. CO has a strong binding affinity to hemoglobin, making it highly toxic. High concentrations can cause varying degrees of poisoning symptoms, damaging the brain, heart, liver, kidneys, lungs, and other tissues, and even leading to death by electric shock. The minimum lethal concentration for human inhalation is 5000 ppm (within 5 minutes). Therefore, strict requirements must be placed on the CO emission levels in the exhaust gases from petrochemical production processes. With increasingly stringent environmental regulations, regions such as Beijing and Zibo have implemented strict controls on the CO concentration in the exhaust gases of chemical plants.

[0003] In some chemical production processes, the generated tail gas contains low concentrations of CO gas (<20,000 ppm) (e.g., the desorption gas and CO2 product gas from the low-temperature methanol washing unit used for acid gas removal in coal gasification plants). Recovery costs for this type of tail gas are high. To meet emission requirements, adsorption, photocatalysis, low-temperature plasma conversion, and combustion are commonly used to remove CO. Among these methods, catalytic oxidation, which introduces a highly efficient catalyst based on combustion to lower the combustion temperature, has attracted widespread attention due to its simple process and high removal efficiency.

[0004] Numerous catalysts for the catalytic oxidation of low-concentration CO have been publicly reported, typically employing noble metals such as Pt and Au as active components. However, CO-containing waste gas from many chemical plants often contains low concentrations of sulfides (<50 ppm, including H2S and COS) due to the influence of preceding processes. These sulfur compounds have a strong poisoning effect on noble metal catalysts, easily leading to catalyst deactivation. Currently, there are few reports on sulfur-resistant carbon monoxide oxidation catalysts, and the few catalysts applicable to the treatment of sulfur-containing CO tail gas usually require relatively harsh reaction conditions.

[0005] Patent application CN114210335A discloses the preparation and application of a low-temperature, water- and sulfur-resistant non-precious metal catalyst for removing carbon monoxide. This catalyst is a perovskite-type transition metal oxide (general formula La). 1x Sr x CoO3). This catalyst can achieve 0.1000 mg Nm 3 SO2 and 0.20 vol.% water vapor in 10,000 ppm carbon monoxide flue gas at 120-150 °C for 3000-30000 h⁻¹1 Under space velocity conditions, the efficiency of carbon monoxide removal remained stable at over 80%, but the activity and stability of the catalyst in the presence of other sulfur species such as H2S were not indicated.

[0006] Patent application CN111659415A discloses a method for preparing a coupled nanocomposite noble metal catalyst on an activated alumina support. This catalyst uses activated alumina as the support, CeO2, Fe3O4, MnO2, and CuO2 coupled metal oxides as modifiers, and Pd and Pt as the dual noble metals as the active components. At 25°C, with an inlet CO concentration of 5000 ppm, an H2S content of 5 ppm, and a space velocity of 10000 h⁻¹, the catalyst can be prepared in various conditions. -1 Under certain conditions, the CO removal rate remained at 100% for a reaction time of 50 hours. However, the catalyst has a complex composition and a relatively complicated preparation method. Furthermore, the changes in hydrogen sulfide during the reaction are not mentioned, making it impossible to further predict the catalyst's lifetime. The reported catalyst lifetime is significantly different from that required for industrial applications.

[0007] Therefore, given the characteristics of sulfur-containing species in CO tail gas from the petrochemical industry, developing CO oxidation catalysts with inherent sulfur resistance has become an urgent problem to be solved. Summary of the Invention

[0008] The purpose of this invention is to address the treatment of low-concentration CO tail gas in industrial production processes, including coal chemical engineering, by providing a sulfur-resistant noble metal-based CO oxidation catalyst, its preparation method, and its applications to improve the catalytic stability of catalysts in the presence of sulfides (such as hydrogen sulfide). The sulfur-resistant noble metal-based CO oxidation catalyst of this invention is prepared through pre-reduction and induced activation of the catalyst matrix, forming a specific surface-interface structure that enables the catalyst to selectively oxidize sulfur-containing species, thus achieving excellent sulfur resistance in the carbon monoxide oxidation reaction.

[0009] To achieve the above objectives, the present invention provides a sulfur-resistant noble metal-based CO oxidation catalyst, which contains a support and an active component and an auxiliary agent supported on the support. The active component is Pt and / or Pd, the auxiliary agent is at least one of Fe, Co and Ni, and the support is at least one of titanium dioxide, cerium dioxide, alumina and zirconium dioxide. The active component and a portion of the auxiliary agent form alloy particles.

[0010] Preferably, the sulfur-resistant noble metal-based CO oxidation catalyst forms a Pt / Pd-A / AO catalyst. x / MO x Surface-interface structure, wherein Pt / Pd-A are alloy particles of active components and additives, and are in a sulfur hybrid state, AO x MO is an oxide of an auxiliary metal. xAs a carrier.

[0011] Preferably, based on the total weight of the sulfur-resistant noble metal-based CO oxidation catalyst, the loading of the active component, calculated as metal element, is 0.1-1 wt%, and the loading of the auxiliary agent, calculated as metal element, is 0.1-3 wt%.

[0012] A second aspect of this invention provides a method for preparing a sulfur-resistant noble metal-based CO oxidation catalyst, comprising the following steps:

[0013] (1) The support is immersed in an aqueous solution containing a noble metal precursor and an auxiliary precursor, and then dried and calcined to obtain the catalyst parent material;

[0014] (2) The catalyst precursor is pre-reduced in a hydrogen-containing atmosphere to obtain a catalyst intermediate;

[0015] (3) The catalyst intermediate is induced to activate in an atmosphere containing CO and H2S;

[0016] Wherein, the noble metal is Pt and / or Pd, the support is at least one of titanium dioxide, cerium dioxide, aluminum oxide and zirconium dioxide, and the metal element in the auxiliary precursor is at least one of Fe, Co and Ni.

[0017] Preferably, in step (1), the impregnation process is an equal-volume impregnation.

[0018] Preferably, the impregnation process includes a stirring stage and a settling stage, wherein the stirring stage lasts for 0.5-1 hour and the settling stage lasts for 6-18 hours.

[0019] Preferably, in step (1), the carrier is pre-cooked before impregnation.

[0020] Preferably, the calcination conditions of the carrier include: a temperature of 400-700℃ and a calcination time of 4-8h.

[0021] Preferably, the particle size of the carrier is 10-500 nm, and the specific surface area is 60-200 m². 2 / g.

[0022] Preferably, in step (1), the noble metal precursor is at least one of chloroplatinic acid, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate, and palladium acetate.

[0023] Preferably, in step (1), the auxiliary precursor is at least one of the nitrate, chloride and sulfate of the auxiliary metal, more preferably the nitrate of the auxiliary metal.

[0024] Preferably, in step (1), during the drying process, the drying temperature is 60-90℃ and the drying time is 12-24h; during the calcination process, the calcination temperature is 400-600℃ and the calcination time is 3-6h, and the heating rate is 1-3℃ / min.

[0025] Preferably, in step (2), the hydrogen content in the pre-reduction treatment atmosphere is 5-50% by volume, preferably 5-10% by volume.

[0026] Preferably, the temperature of the pre-reduction treatment is 300-500℃.

[0027] Preferably, in step (3), the atmosphere for inducing activation contains CO, H2S and N2, wherein the CO content is 2-5% by volume, the H2S content is 50-200 ppm, and the N2 content is 95-98% by volume.

[0028] Preferably, the temperature for inducing activation is 200-350℃.

[0029] The present invention also provides a sulfur-resistant noble metal-based CO oxidation catalyst prepared by the above method.

[0030] The present invention also provides the application of the above-mentioned sulfur-resistant noble metal-based CO oxidation catalyst as a catalyst for carbon monoxide oxidation reaction.

[0031] Preferably, the reaction gas used in the carbon monoxide oxidation process contains less than 50 ppm of sulfides.

[0032] The technical solution of the present invention has the following advantages:

[0033] (1) Compared with other carbon monoxide oxidation catalysts, the sulfur-resistant noble metal-based CO oxidation catalyst of the present invention can achieve highly selective oxidation of hydrogen sulfide species to sulfur dioxide, reducing the adsorption and deposition of sulfur species on the catalyst.

[0034] (2) Compared with other carbon monoxide oxidation catalysts, the sulfur-resistant noble metal-based CO oxidation catalyst of the present invention exhibits better performance at a space velocity of 10,000 h⁻¹. -1 With a reaction temperature of 250℃, a CO concentration of 6000ppm and 50ppm hydrogen sulfide in the reaction feed gas, the CO conversion rate remained above 99% after a reaction time of 200h.

[0035] The sulfur-resistant noble metal-based CO oxidation catalyst of this invention has a simple composition and preparation method, low preparation cost, good reproducibility, and is suitable for large-scale production. Furthermore, it exhibits high efficiency and stability. Based on the catalyst described in this invention, a low-concentration carbon monoxide catalytic removal technology can be formed, applicable to various low-concentration carbon monoxide removal conditions, including those involving the presence of sulfides. It can reduce the carbon monoxide concentration in exhaust gas to below 50 ppm, and can be widely used in exhaust gas treatment in petrochemical, steel, industrial kilns, and waste incineration processes. This is of great significance for protecting the atmospheric environment and safeguarding human health. Attached Figure Description

[0036] Figure 1 This is a graph showing the CO oxidation conversion rate catalyzed by the PtFe / TiO2 catalyst in Example 1;

[0037] Figure 2 This is a TEM image of the PtFe / TiO2 catalyst in Example 1;

[0038] Figure 3 This is a STEM-HAADF image of the PtFe / TiO2 catalyst in Example 1;

[0039] Figure 4 This is an HRTEM image of the PtFe / TiO2 catalyst in Example 1;

[0040] Figure 5 This is a STEM-HAADF image of the catalyst Pt / Fe / TiO2 in Comparative Example 1. Detailed Implementation

[0041] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0042] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0043] Unless otherwise specified, the mass percentage of each component constituting the catalyst in this application refers to the mass percentage of the corresponding component relative to the mass of the catalyst.

[0044] Unless otherwise specified, the content of each component in the gas composition used for catalyst pre-reduction and induced activation in this application refers to the volume percentage of the corresponding component in the total gas volume.

[0045] The sulfur-resistant noble metal-based CO oxidation catalyst of the present invention comprises a support and an active component and an auxiliary agent supported on the support. The active component is Pt and / or Pd. The auxiliary agent is at least one selected from Fe, Co, and Ni. The support is at least one selected from titanium dioxide, cerium dioxide, alumina, and zirconium dioxide.

[0046] In the catalyst described in this invention, a portion of the promoter metal forms alloy particles with noble metals Pt and / or Pd, while a portion exists in the form of an oxide. Specifically, the active component Pt and / or Pd forms alloy particles with a portion of the promoter metal A, namely Pt / Pd-A alloy particles. These Pt / Pd-A alloy particles are highly dispersed in the catalyst and, after induced activation, transform into sulfur hybrid alloy particles. The average particle size of the Pt / Pd-A alloy particles can be 4-6 nm.

[0047] In a preferred embodiment of the catalyst described in this invention, the catalyst is prepared by volume impregnation-drying-calcination-pre-reduction-induced activation to form Pt / Pd-A alloy metal active particles and to form Pt / Pd-A / AO alloy particles. x / MO x Surface-interface structure, wherein Pt / Pd-A are alloy particles of active components and additives, and are in a sulfur hybrid state, AO x MO is an oxide of an auxiliary metal. x As a carrier.

[0048] In the catalyst of the present invention, based on the total weight of the sulfur-resistant noble metal-based CO oxidation catalyst, the loading of the active component, calculated as metal element, is 0.1-1 wt%, preferably 0.2-0.8 wt%, more preferably 0.3-0.6 wt%; the loading of the auxiliary agent, calculated as metal element, is 0.1-3 wt%, preferably 0.3-2 wt%, more preferably 0.8-1.5 wt%.

[0049] The preparation method of the sulfur-resistant noble metal-based CO oxidation catalyst of the present invention includes the following steps:

[0050] (1) The support is immersed in an aqueous solution containing a noble metal precursor and an auxiliary precursor, and then dried and calcined to obtain the catalyst parent material;

[0051] (2) The catalyst precursor is pre-reduced in a hydrogen-containing atmosphere to obtain a catalyst intermediate;

[0052] (3) The catalyst intermediate is induced to activate in an atmosphere containing CO and H2S.

[0053] In the method described in this invention, the support is at least one selected from titanium dioxide, cerium dioxide, aluminum oxide, and zirconium dioxide. The particle size of the support can be 10-500 nm, and the specific surface area can be 60-200 m². 2 / g. In one embodiment, when the carrier is titanium dioxide, anatase nano-titanium dioxide white powder is preferred, with a purity of 99.9% or higher, a particle size of 15-60 nm, and a specific surface area of ​​60-120 m². 2 / g, the carrier has a large specific surface area and good hydrophilicity. In another embodiment, when the carrier is cerium dioxide, alumina, or zirconium dioxide, its purity is preferably 99.99% or higher.

[0054] In the method described in this invention, the carrier is pre-calcined before impregnation. The calcination conditions of the carrier may include: a temperature of 400-700℃ and a calcination time of 4-8 hours.

[0055] In the method described in this invention, the noble metal in the noble metal precursor is Pt and / or Pd. The noble metal precursor can be at least one of chloroplatinic acid, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate, and palladium acetate, preferably chloroplatinic acid and / or palladium nitrate.

[0056] In the method described in this invention, the metal element (i.e., auxiliary metal A) in the auxiliary precursor is at least one of Fe, Co, and Ni. The auxiliary precursor can be at least one of a nitrate, chloride, and sulfate of the auxiliary metal, preferably a nitrate of the auxiliary metal.

[0057] In the method described in this invention, the impregnation process in step (1) is preferably equal-volume impregnation. The specific operation process of equal-volume impregnation includes:

[0058] (I) The saturated water absorption rate of the calcined carrier was tested. The specific method was as follows: a certain mass m1 of the carrier was weighed and placed into a graduated cylinder to obtain its close-packed volume V1; a certain mass m2 of deionized water was added and its volume V2 was recorded; after thorough stirring and standing for 12-24 hours, the volume V3 of the mixed liquid in the graduated cylinder was read. The saturated water absorption rate ω of the sample was calculated by the following formula:

[0059]

[0060] (II) Calculate the weight of the noble metal precursor and the auxiliary precursor according to the mass of the support required for the preparation of the catalyst. Dissolve the noble metal precursor and the auxiliary precursor substances calculated according to the loading of noble metal (i.e., Pt and / or Pd) and auxiliary metal A in deionized water. The volume of deionized water required for dissolution is obtained by calculating the saturated water absorption based on the weight of the support for the preparation of the catalyst. After dissolution, the clear precursor solution is left to stand for later use.

[0061] (III) Add the calcined carrier to the prepared precursor solution, allowing the carrier to fully absorb the precursor solution. Stir for a period of time at room temperature to obtain a slurry-like mixture, and then let it stand for a period of time.

[0062] The impregnation process in step (III) includes a stirring stage and a settling stage. The stirring stage lasts for 0.5-1 hour, and the settling stage lasts for 6-18 hours.

[0063] In the method described in this invention, in step (1), the drying temperature is 60-90℃ and the drying time is 12-24h. The drying process can be carried out in a forced-air drying oven.

[0064] In the method described in this invention, in step (1), during the calcination process, the calcination temperature is 400-600℃, the calcination time is 3-6h, and the heating rate is 1-3℃ / min. The calcination process can be carried out in a muffle furnace.

[0065] In the method described in this invention, in step (2), the hydrogen content in the pre-reduction treatment atmosphere is 5-50% by volume, preferably 5-20% by volume, and more preferably 5-10% by volume. Besides hydrogen, the other gases in the pre-reduction treatment atmosphere can be inert gases, such as argon.

[0066] In the method described in this invention, in step (2), the temperature of the pre-reduction treatment is 300-500℃. The time of the pre-reduction treatment can be 0.5-2 hours, preferably 1 hour.

[0067] In the method described in this invention, during step (3), the catalyst structure undergoes a directional change during the induced activation process. The H2S component in the reaction gas is selectively oxidized to SO2, and the SO2 concentration in the tail gas gradually increases with the extension of the induction time. After a period of induction time, the sulfur concentration in the reactor reaches equilibrium, and sulfur species will not continue to deposit on the catalyst. During the catalyst induced activation process, the CO oxidation reaction conversion rate is always maintained above 99%, thus achieving an inherently sulfur-resistant reaction. Depending on the composition of the catalyst and the composition of the reaction induction gas, the induction period required from the start of reaction induction to the sulfur equilibrium at the reactor inlet and outlet varies, with an induction time of 6-15 hours. In a preferred embodiment, the atmosphere for induced activation contains CO, H2S, and N2, wherein the CO content is 2-5% by volume, the H2S content is 50-200 ppm, and the N2 content is 95-98% by volume.

[0068] In the method described in this invention, in step (3), the temperature for induction activation is 200-350℃.

[0069] According to a specific embodiment of the present invention, the preparation method of the sulfur-resistant noble metal-based CO oxidation catalyst includes:

[0070] S1. Add the calcined carrier to the prepared precursor solution (including precious metal precursor and auxiliary agent precursor), so that the carrier can fully absorb the precursor solution, stir and mix at room temperature, and then let stand to obtain a slurry-like mixture.

[0071] S2. The slurry mixture is placed in a forced-air drying oven for drying, and then placed in a muffle furnace for calcination to obtain the catalyst matrix;

[0072] S3. The catalyst matrix is ​​placed in a flowing fixed-bed reactor and pre-reduced under an H2 / Ar mixed gas atmosphere. Then the gas is switched to a CO / H2S / N2 mixed gas and induced activation is performed under the atmosphere of the mixer.

[0073] This invention also provides a sulfur-resistant noble metal-based CO oxidation catalyst prepared by the above method. In this invention, by pre-reducing and induced activation of the catalyst matrix, specific catalytic active sites and surface-interface structures are formed, enabling highly selective oxidation of H2S species, inhibiting the adsorption of S species and the formation of sulfate, and achieving a high-conversion oxidation reaction of carbon monoxide in the presence of H2S.

[0074] This invention also provides the application of the aforementioned sulfur-resistant noble metal-based CO oxidation catalyst as a catalyst for carbon monoxide oxidation. Specifically, the sulfur-resistant noble metal-based CO oxidation catalyst of this invention can be applied to various low-concentration carbon monoxide removal conditions, especially various low-concentration carbon monoxide removal conditions in the presence of sulfides. In one specific embodiment, the reactant gas used in the carbon monoxide oxidation reaction contains less than 50 ppm of sulfides.

[0075] Based on the catalyst described in this invention, a low-concentration carbon monoxide catalytic removal technology can be formed, which is applicable to various low-concentration carbon monoxide removal conditions, including the presence of sulfides. It can reduce the carbon monoxide concentration in the exhaust gas to below 50 ppm and can be widely used in exhaust gas treatment in petrochemical, steel, industrial kiln, and waste incineration processes. It is of great significance for protecting the atmospheric environment and safeguarding human health.

[0076] The following examples further illustrate the sulfur-resistant noble metal-based CO oxidation catalyst, its preparation method, and its application according to the present invention. The examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0077] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0078] Example 1

[0079] Preparation of inherently sulfur-resistant PtFe / TiO2 catalyst:

[0080] Weigh 0.1g of chloroplatinic acid (H2PtCl6) and add it to a 1L volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 1L. After the solution becomes clear and uniform, let it stand for later use.

[0081] Commercially available anatase nano-titanium dioxide carriers (purity above 99.9%, particle size 15-60 nm, specific surface area 60-120 m²) will be used. 2 / g), placed in a muffle furnace, and calcined at 500℃ in air atmosphere for 4 hours, with a heating rate of 3℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for storage.

[0082] Saturated water absorption rate determination: Weigh 1g of calcined TiO2 support and add it to a 5mL graduated cylinder. After compacting it on a flat surface, the volume of the densely packed mixture is recorded as 1mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The volume of the mixed liquid is recorded as 2.3mL. The saturated water absorption rate of the TiO2 support is calculated to be 0.7mL / g.

[0083] Weigh 1.52 g of the prepared chloroplatinic acid solution and add it together with 1.16 g of ferric nitrate (Fe(NO3)3·9H2O) into a 50 mL beaker. Add 6.3 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of TiO2 support and stir at room temperature for 0.5 h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film. Let it stand in a cool, dry place for 12 h.

[0084] The slurry-like catalyst was placed in a crucible and heated in a muffle furnace under air atmosphere 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 allowed to cool naturally to room temperature, removed, and sealed for storage.

[0085] The prepared catalyst precursor was placed in a fixed-bed microreactor and pre-reduced at 500℃ for 1 h in a mixed atmosphere of 100 mL / min of 10 vol% H2 / 90 vol% Ar. Then, the gas was switched to a mixed atmosphere of 2 vol% CO / 0.005 vol% H2S / 97.995 vol% N2 for induction activation. During induction, the sulfide content in the tail gas at the reactor outlet was analyzed using gas chromatography. Activation was considered complete when the sulfide content in the tail gas was the same as the sulfur content in the induction gas. Subsequently, the gas was switched to a mixture of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2 for carbon monoxide oxidation reaction evaluation. The reaction temperature was set at 250℃ and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were detected using gas chromatography. The reaction results for the CO conversion rate catalyzed by the PtFe / TiO2 catalyst are as follows: Figure 1 As shown, from Figure 1 As can be seen, during the 200-hour long-cycle carbon monoxide oxidation reaction, the carbon monoxide conversion rate remained above 99%.

[0086] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtFe / TiO2 catalyst was 0.41 wt% and the Fe content (calculated as metal element) was 1.20 wt%.

[0087] The transmission electron microscopy (TEM) image of the PtFe / TiO2 catalyst obtained after induced activation is shown below. Figure 2 As shown.

[0088] The results obtained from high-footed annular dark-field scanning transmission electron microscopy (STEM-HAADF) show (see...) Figure 3In this catalyst PtFe / TiO2, Pt and some Fe exist in the form of Pt-Fe alloy particles, and the average particle size of the Pt-Fe alloy particles is about 5 nm. After induced activation, the alloy particles are in a sulfur hybrid state.

[0089] The high-resolution transmission electron microscopy (HRTEM) image of this PtFe / TiO2 catalyst (see...) Figure 4 It can be seen that after induced activation, a unique Pt-Fe / Fe2O3 / TiO2 surface-interface structure is formed on the catalyst, which is beneficial to improving the catalytic reaction activity and stability.

[0090] Example 2

[0091] Preparation of inherently sulfur-resistant PtCo / ZrO2 catalyst:

[0092] Weigh 0.1g of chloroplatinic acid (H2PtCl6) and add it to a 1L volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 1L. After the solution becomes clear and uniform, let it stand for later use.

[0093] The nano-zirconia carrier (particle size 10-500nm, specific surface area 60-200m²) purchased from Sinopharm Chemical Reagent Co., Ltd. 2 / g), placed in a muffle furnace, and calcined at 500℃ in air atmosphere for 4 hours, with a heating rate of 3℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for storage.

[0094] Saturated water absorption rate determination: Weigh 1g of calcined ZrO2 support and add it to a 5mL graduated cylinder. After compacting it on a flat surface, the volume of the densely packed mixture is recorded as 0.65mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The volume of the mixed liquid is recorded as 2.3mL. The saturated water absorption rate of the ZrO2 support is calculated to be 0.35mL / g.

[0095] Weigh 1.52 g of the prepared chloroplatinic acid solution and add it together with 1.16 g of cobalt nitrate (Co(NO3)2·6H2O) into a 50 mL beaker. Add 3.2 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of ZrO2 support and stir at room temperature for 0.5 h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film. Let it stand in a cool, dry place for 12 h.

[0096] The slurry-like catalyst was placed in a crucible and heated in a muffle furnace under air atmosphere 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 allowed to cool naturally to room temperature, removed, and sealed for storage.

[0097] The prepared catalyst precursor was placed in a fixed-bed microreactor and pretreated at 500℃ for 1 h in a mixed atmosphere of 100 mL / min of 10 vol% H2 / 90 vol% Ar. Then, the gas was switched to a mixed atmosphere of 2.5 vol% CO / 0.01 vol% H2S / 97.49 vol% N2 for induced activation. During the induced activation process, the sulfide content in the tail gas at the reactor outlet was analyzed using gas chromatography. Activation was considered complete when the sulfide content in the tail gas was the same as the sulfur content in the induced gas. Subsequently, the gas was switched to a mixture of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2 for carbon monoxide oxidation reaction evaluation. The reaction temperature was set at 250℃ and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were detected using gas chromatography. The results showed that the induction period required from the start of activation to sulfur equilibrium at the reactor inlet and outlet was 14 hours. During the 200-hour long-cycle carbon monoxide oxidation reaction, the carbon monoxide conversion rate remained above 99%.

[0098] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtCo / ZrO2 catalyst was 0.53 wt% and the Co content (calculated as metal element) was 1.97 wt%.

[0099] High-resolution annular dark-field scanning transmission electron microscopy (STEM-HAADF) revealed that Pt and some Co in the PtCo / ZrO2 catalyst exist as Pt-Co alloy particles with an average particle size of 6 nm. The alloy particles after induced activation are in a sulfur hybrid state. High-resolution transmission electron microscopy characterization showed the formation of Pt-Co / CoO2 on the catalyst. x / ZrO2 surface-interface structure.

[0100] Example 3

[0101] Preparation of inherently sulfur-resistant PtNi / CeO2 catalyst:

[0102] Weigh 0.1g of chloroplatinic acid (H2PtCl6) and add it to a 1L volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 1L. After the solution becomes clear and uniform, let it stand for later use.

[0103] The nano-cerium dioxide carrier (particle size 10-500nm, specific surface area 60-200m²) purchased from Sinopharm Chemical Reagent Co., Ltd. 2 / g), placed in a muffle furnace, and calcined at 500℃ in air atmosphere for 4 hours, with a heating rate of 3℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for storage.

[0104] Saturated water absorption rate determination: Weigh 1g of calcined CeO2 support and add it to a 5mL graduated cylinder. After compacting it on a flat surface, the volume of the densely packed mixture is recorded as 0.8mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The volume of the mixed liquid is recorded as 2.2mL. The saturated water absorption rate of the CeO2 support is calculated to be 0.6mL / g.

[0105] Weigh 1.52 g of the prepared chloroplatinic acid solution and add it together with 1.16 g of nickel nitrate (Ni(NO3)2·6H2O) into a 50 mL beaker. Add 3.2 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of CeO2 support and stir at room temperature for 0.5 h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film. Let it stand in a cool, dry place for 12 h.

[0106] The slurry-like catalyst was placed in a crucible and heated in a muffle furnace under air atmosphere 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 allowed to cool naturally to room temperature, removed, and sealed for storage.

[0107] The prepared catalyst precursor was placed in a fixed-bed microreactor and pretreated at 500℃ for 1 h in a mixed atmosphere of 5 vol% H2 / 95 vol% Ar at a flow rate of 100 mL / min. Then, the gas was switched to a mixed atmosphere of 5 vol% CO / 0.02 vol% H2S / 94.98 vol% N2 for induced activation. During the induced activation process, the sulfide content in the tail gas at the reactor outlet was analyzed using gas chromatography. Activation was considered complete when the sulfide content in the tail gas was the same as the sulfur content in the induced gas. Subsequently, the gas was switched to a mixture of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2 for carbon monoxide oxidation reaction evaluation. The reaction temperature was set at 250℃ and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were detected using gas chromatography. The results showed that the induction period required from the start of activation to sulfur equilibrium at the reactor inlet and outlet was 18 hours. During the 200-hour long-cycle carbon monoxide oxidation reaction, the carbon monoxide conversion rate remained above 99%.

[0108] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtNi / CeO2 catalyst was 0.51 wt% and the Ni content (calculated as metal element) was 1.48 wt%.

[0109] High-resolution annular dark-field scanning transmission electron microscopy (STEM-HAADF) results revealed that Pt and some Ni in the PtNi / CeO2 catalyst exist in the form of Pt-Ni alloy particles, with an evaluated particle size of 4 nm. The alloy particles after induced activation are in a sulfur hybrid state. High-resolution transmission electron microscopy characterization showed that Pt-Ni / NiO formed on the catalyst. x / CeO2 surface-interface structure.

[0110] Example 4

[0111] Preparation of inherently sulfur-resistant PtFe / TiO2 catalyst:

[0112] Weigh 0.1g of chloroplatinic acid (H2PtCl6) and add it to a 1L volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 1L. After the solution becomes clear and uniform, let it stand for later use.

[0113] Commercially available anatase nano-titanium dioxide carriers (purity above 99.9%, particle size 15-60 nm, specific surface area 60-120 m²) will be used. 2 / g), placed in a muffle furnace, and calcined at 400℃ in air atmosphere for 8 hours, with a heating rate of 1℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for later use.

[0114] Saturated water absorption rate determination: Weigh 1g of calcined TiO2 support and add it to a 5mL graduated cylinder. After compacting it on a flat surface, the volume of the densely packed mixture is recorded as 1mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The volume of the mixed liquid is recorded as 2.3mL. The saturated water absorption rate of the TiO2 support is calculated to be 0.7mL / g.

[0115] Weigh 1.19 g of the prepared chloroplatinic acid solution and add it together with 0.77 g of ferric nitrate (Fe(NO3)3·9H2O) into a 50 mL beaker. Add 6.3 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of TiO2 support and stir at room temperature for 0.5 h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film. Let it stand in a cool, dry place for 12 h.

[0116] The slurry-like catalyst was placed in a crucible and heated in a muffle furnace under air atmosphere from room temperature to 400°C at a heating rate of 1°C / min, and calcined at 400°C for 6 hours. After calcination, it was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0117] The prepared catalyst precursor was placed in a fixed-bed microreactor and pre-reduced at 400℃ for 1 h in a mixed atmosphere of 100 mL / min of 10 vol% H2 / 90 vol% Ar. Then, the gas was switched to a mixed atmosphere of 2 vol% CO / 0.005 vol% H2S / 97.995 vol% N2 for induction activation. During induction, the sulfide content in the tail gas at the reactor outlet was analyzed using gas chromatography. Activation was considered complete when the sulfide content in the tail gas was the same as the sulfur content in the induction gas. Subsequently, the gas was switched to a mixture of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2 for carbon monoxide oxidation reaction evaluation. The reaction temperature was set at 250℃ and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were detected using gas chromatography. The reaction results for the CO conversion rate catalyzed by the PtFe / TiO2 catalyst are as follows: Figure 1 As shown, from Figure 1 As can be seen, during the 200-hour long-cycle carbon monoxide oxidation reaction, the carbon monoxide conversion rate remained above 99%.

[0118] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtFe / TiO2 catalyst was 0.32% by weight, and the Fe content (calculated as metal element) was 0.81% by weight.

[0119] The results of high-resolution annular dark-field scanning transmission electron microscopy (STEM-HAADF) show that Pt and some Fe in the catalyst PtFe / TiO2 exist in the form of Pt-Fe alloy particles, and the average particle size of the Pt-Fe alloy particles is about 5 nm. After induced activation, the alloy particles are in a sulfur hybrid state. High-resolution transmission electron microscopy characterization shows that after induced activation, a Pt-Fe / Fe2O3 / TiO2 surface-interface structure is formed on the catalyst.

[0120] Example 5

[0121] Preparation of inherently sulfur-resistant PtFe / TiO2 catalyst:

[0122] Weigh 0.1g of chloroplatinic acid (H2PtCl6) and add it to a 1L volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 1L. After the solution becomes clear and uniform, let it stand for later use.

[0123] Commercially available anatase nano-titanium dioxide carriers (purity above 99.9%, particle size 15-60 nm, specific surface area 60-120 m²) will be used. 2 / g), placed in a muffle furnace, and calcined at 700℃ in air atmosphere for 4 hours, with a heating rate of 2℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for storage.

[0124] Saturated water absorption rate determination: Weigh 1g of calcined TiO2 support and add it to a 5mL graduated cylinder. After compacting it on a flat surface, the volume of the densely packed mixture is recorded as 1mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The volume of the mixed liquid is recorded as 2.3mL. The saturated water absorption rate of the TiO2 support is calculated to be 0.7mL / g.

[0125] Weigh 2.19 g of the prepared chloroplatinic acid solution and add it together with 1.45 g of ferric nitrate (Fe(NO3)3·9H2O) into a 50 mL beaker. Add 6.3 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of TiO2 support and stir at room temperature for 0.5 h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film. Let it stand in a cool, dry place for 12 h.

[0126] The slurry-like catalyst was placed in a crucible and heated in a muffle furnace under air atmosphere from room temperature to 600°C at a heating rate of 3°C / min, and calcined at 600°C for 3 hours. After calcination, it was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0127] The prepared catalyst precursor was placed in a fixed-bed microreactor and pre-reduced at 450℃ for 1 h in a mixed atmosphere of 100 mL / min of 10 vol% H2 / 90 vol% Ar. Then, the gas was switched to a mixed atmosphere of 2 vol% CO / 0.005 vol% H2S / 97.995 vol% N2 for induction activation. During induction, the sulfide content in the tail gas at the reactor outlet was analyzed using gas chromatography. Activation was considered complete when the sulfide content in the tail gas was the same as the sulfur content in the induction gas. Subsequently, the gas was switched to a mixture of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2 for carbon monoxide oxidation reaction evaluation. The reaction temperature was set at 250℃ and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were detected using gas chromatography. The reaction results for the CO conversion rate catalyzed by the PtFe / TiO2 catalyst are as follows: Figure 1 As shown, from Figure 1 As can be seen, during the 200-hour long-cycle carbon monoxide oxidation reaction, the carbon monoxide conversion rate remained above 99%.

[0128] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtFe / TiO2 catalyst was 0.59 wt% and the Fe content (calculated as metal element) was 1.48 wt%.

[0129] The results of high-resolution annular dark-field scanning transmission electron microscopy (STEM-HAADF) show that Pt and some Fe in the catalyst PtFe / TiO2 exist in the form of Pt-Fe alloy particles, and the average particle size of the Pt-Fe alloy particles is about 5 nm. After induced activation, the alloy particles are in a sulfur hybrid state. High-resolution transmission electron microscopy characterization shows that after induced activation, a Pt-Fe / Fe2O3 / TiO2 surface-interface structure is formed on the catalyst.

[0130] Example 6

[0131] Preparation of inherently sulfur-resistant PtCo / ZrO2 catalyst:

[0132] Weigh 0.1g of chloroplatinic acid (H2PtCl6) and add it to a 1L volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 1L. After the solution becomes clear and uniform, let it stand for later use.

[0133] The nano-zirconia carrier (particle size 10-500nm, specific surface area 60-200m²) purchased from Sinopharm Chemical Reagent Co., Ltd. 2 / g), placed in a muffle furnace, and calcined at 400℃ in air atmosphere for 8 hours, with a heating rate of 1℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for later use.

[0134] Saturated water absorption rate determination: Weigh 1g of calcined ZrO2 support and add it to a 5mL graduated cylinder. After compacting it on a flat surface, the volume of the densely packed mixture is recorded as 0.65mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The volume of the mixed liquid is recorded as 2.3mL. The saturated water absorption rate of the ZrO2 support is calculated to be 0.35mL / g.

[0135] Weigh 0.95 g of the prepared chloroplatinic acid solution and add it together with 0.73 g of cobalt nitrate (Co(NO3)2·6H2O) into a 50 mL beaker. Add 3.2 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of ZrO2 support and stir at room temperature for 0.5 h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film. Let it stand in a cool, dry place for 12 h.

[0136] The slurry-like catalyst was placed in a crucible and heated in a muffle furnace under air atmosphere from room temperature to 400°C at a heating rate of 1°C / min, and calcined at 400°C for 6 hours. After calcination, it was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0137] The prepared catalyst precursor was placed in a fixed-bed microreactor and pretreated at 400℃ for 1 h in a mixed atmosphere of 100 mL / min of 10 vol% H2 / 90 vol% Ar. Then, the gas was switched to a mixed atmosphere of 2.5 vol% CO / 0.01 vol% H2S / 97.49 vol% N2 for induced activation. During the induced activation process, the sulfide content in the tail gas at the reactor outlet was analyzed using gas chromatography. Activation was considered complete when the sulfide content in the tail gas was the same as the sulfur content in the induced gas. Subsequently, the gas was switched to a mixture of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2 for carbon monoxide oxidation reaction evaluation. The reaction temperature was set at 250℃ and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were detected using gas chromatography. The results showed that the induction period required from the start of activation to sulfur equilibrium at the reactor inlet and outlet was 14 hours. During the 200-hour long-cycle carbon monoxide oxidation reaction, the carbon monoxide conversion rate remained above 99%.

[0138] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtCo / ZrO2 catalyst was 0.33 wt% and the Co content (calculated as metal element) was 1.67 wt%.

[0139] High-resolution annular dark-field scanning transmission electron microscopy (STEM-HAADF) revealed that Pt and some Co in the PtCo / ZrO2 catalyst exist as Pt-Co alloy particles with an average particle size of 6 nm. The alloy particles after induced activation are in a sulfur hybrid state. High-resolution transmission electron microscopy characterization showed the formation of Pt-Co / CoO2 on the catalyst. x / ZrO2 surface-interface structure.

[0140] Example 7

[0141] Preparation of inherently sulfur-resistant PtCo / ZrO2 catalyst:

[0142] Weigh 0.1g of chloroplatinic acid (H2PtCl6) and add it to a 1L volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 1L. After the solution becomes clear and uniform, let it stand for later use.

[0143] The nano-zirconia carrier (particle size 10-500nm, specific surface area 60-200m²) purchased from Sinopharm Chemical Reagent Co., Ltd. 2 / g), placed in a muffle furnace, and calcined at 700℃ in air atmosphere for 4 hours, with a heating rate of 2℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for storage.

[0144] Saturated water absorption rate determination: Weigh 1g of calcined ZrO2 support and add it to a 5mL graduated cylinder. After compacting it on a flat surface, the volume of the densely packed mixture is recorded as 0.65mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The volume of the mixed liquid is recorded as 2.3mL. The saturated water absorption rate of the ZrO2 support is calculated to be 0.35mL / g.

[0145] Weigh 1.29 g of the prepared chloroplatinic acid solution and add it together with 0.81 g of cobalt nitrate (Co(NO3)2·6H2O) into a 50 mL beaker. Add 3.2 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of ZrO2 support and stir at room temperature for 0.5 h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film. Let it stand in a cool, dry place for 12 h.

[0146] The slurry-like catalyst was placed in a crucible and heated in a muffle furnace under air atmosphere from room temperature to 600°C at a heating rate of 3°C / min, and calcined at 600°C for 3 hours. After calcination, it was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0147] The prepared catalyst precursor was placed in a fixed-bed microreactor and pretreated at 450℃ for 1 h in a mixed atmosphere of 100 mL / min of 10 vol% H2 / 90 vol% Ar. Then, the gas was switched to a mixed atmosphere of 2.5 vol% CO / 0.01 vol% H2S / 97.49 vol% N2 for induced activation. During the induced activation process, the sulfide content in the tail gas at the reactor outlet was analyzed using gas chromatography. Activation was considered complete when the sulfide content in the tail gas was the same as the sulfur content in the induced gas. Subsequently, the gas was switched to a mixture of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2 for carbon monoxide oxidation reaction evaluation. The reaction temperature was set at 250℃ and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were detected using gas chromatography. The results showed that the induction period required from the start of activation to sulfur equilibrium at the reactor inlet and outlet was 14 hours. During the 200-hour long-cycle carbon monoxide oxidation reaction, the carbon monoxide conversion rate remained above 99%.

[0148] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtCo / ZrO2 catalyst was 0.45 wt% and the Co content (calculated as metal element) was 1.38 wt%.

[0149] High-resolution annular dark-field scanning transmission electron microscopy (STEM-HAADF) revealed that Pt and some Co in the PtCo / ZrO2 catalyst exist as Pt-Co alloy particles with an average particle size of 6 nm. The alloy particles after induced activation are in a sulfur hybrid state. High-resolution transmission electron microscopy characterization showed the formation of Pt-Co / CoO2 on the catalyst. x / ZrO2 surface-interface structure.

[0150] Example 8

[0151] Preparation of inherently sulfur-resistant PtNi / CeO2 catalyst:

[0152] Weigh 0.1g of chloroplatinic acid (H2PtCl6) and add it to a 1L volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 1L. After the solution becomes clear and uniform, let it stand for later use.

[0153] The nano-cerium dioxide carrier (particle size 10-500nm, specific surface area 60-200m²) purchased from Sinopharm Chemical Reagent Co., Ltd. 2 / g), placed in a muffle furnace, and calcined at 600℃ in air atmosphere for 3 hours, with a heating rate of 2℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for later use.

[0154] Saturated water absorption rate determination: Weigh 1g of calcined CeO2 support and add it to a 5mL graduated cylinder. After compacting it on a flat surface, the volume of the densely packed mixture is recorded as 0.8mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The volume of the mixed liquid is recorded as 2.2mL. The saturated water absorption rate of the CeO2 support is calculated to be 0.6mL / g.

[0155] Weigh 1.25 g of the prepared chloroplatinic acid solution and add it together with 0.98 g of nickel nitrate (Ni(NO3)2·6H2O) into a 50 mL beaker. Add 3.2 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of CeO2 support and stir at room temperature for 0.5 h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film. Let it stand in a cool, dry place for 12 h.

[0156] The slurry-like catalyst was placed in a crucible and heated in a muffle furnace under air atmosphere from room temperature to 600°C at a heating rate of 3°C / min, and calcined at 600°C for 3 hours. After calcination, it was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0157] The prepared catalyst precursor was placed in a fixed-bed microreactor and pretreated at 480℃ for 1 h in a mixed atmosphere of 5 vol% H2 / 95 vol% Ar at a flow rate of 100 mL / min. Then, the gas was switched to a mixed atmosphere of 5 vol% CO / 0.02 vol% H2S / 94.98 vol% N2 for induced activation. During the induced activation process, the sulfide content in the tail gas at the reactor outlet was analyzed using gas chromatography. Activation was considered complete when the sulfide content in the tail gas was the same as the sulfur content in the induced gas. Subsequently, the gas was switched to a mixture of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2 for carbon monoxide oxidation reaction evaluation. The reaction temperature was set at 250℃ and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were detected using gas chromatography. The results showed that the induction period required from the start of activation to sulfur equilibrium at the reactor inlet and outlet was 18 hours. During the 200-hour long-cycle carbon monoxide oxidation reaction, the carbon monoxide conversion rate remained above 99%.

[0158] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtNi / CeO2 catalyst was 0.42 wt% and the Ni content (calculated as metal element) was 1.25 wt%.

[0159] High-resolution annular dark-field scanning transmission electron microscopy (STEM-HAADF) results revealed that Pt and some Ni in the PtNi / CeO2 catalyst exist in the form of Pt-Ni alloy particles, with an evaluated particle size of 4 nm. The alloy particles after induced activation are in a sulfur hybrid state. High-resolution transmission electron microscopy characterization showed that Pt-Ni / NiO formed on the catalyst. x / CeO2 surface-interface structure.

[0160] Comparative Examples 1-3

[0161] The preparation methods of Comparative Examples 1, 2, and 3 correspond to those of Examples 1, 2, and 3, respectively. However, the difference lies in the fact that the pre-reduction treatment and induced activation steps were omitted in the catalyst preparation process of Comparative Examples 1-3. The calcined catalyst precursor was directly subjected to carbon monoxide oxidation reaction evaluation in a gas atmosphere of 0.6 vol% CO / 0.005 vol% H2S / 5 vol% O2 / CO2. The reaction temperature was set at 250°C and the reaction space velocity at 10000 h⁻¹. -1 The CO concentration and sulfide content at the reactor outlet were determined using gas chromatography. The activity and stability of each example and comparative example are shown in Table 1.

[0162] High-resolution transmission electron microscopy (HRTEM) characterization revealed that the catalysts prepared in Comparative Examples 1-3 did not contain sulfur-hybridized alloy particles or PtA / AO. x / MO x Surface-interface structure. Taking the catalyst prepared in Comparative Example 1 as an example, its high-footed annular dark-field scanning transmission electron microscopy (STEM-HAADF) characterization results are as follows: Figure 5 As shown, from Figure 5 It can be seen that the platinum species on the catalyst exist in the form of individual particles and do not form a sulfur hybrid alloy structure phase.

[0163] Table 1 shows a comparison of the reactivity evaluations of Examples 1-8 and Comparative Examples 1-3, where T50 and T90 refer to the lowest temperatures at which the conversion rate reaches 50% and 90%, respectively.

[0164] Table 1

[0165]

[0166]

[0167] The results of the above examples and comparative examples show that the sulfur-resistant noble metal-based CO oxidation catalyst prepared by the method of the present invention exhibits significantly better catalytic activity and stability than the catalyst prepared in the comparative examples. This demonstrates that the combination of pre-reduction and induced activation in the catalyst preparation process can promote the formation of a special catalyst structure, thereby enhancing both the catalyst's reactivity and its sulfur-resistant stability.

[0168] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A sulfur-resistant noble metal-based CO oxidation catalyst, characterized in that, The device comprises a carrier and an active component and an additive loaded on the carrier, wherein the active component is Pt and / or Pd, the additive is at least one of Fe, Co and Ni, and the carrier is at least one of titanium dioxide, cerium dioxide, aluminum oxide and zirconium dioxide, wherein the active component and a portion of the additive form alloy particles; The preparation method of the sulfur-resistant noble metal-based CO oxidation catalyst includes the following steps: (1) The support is immersed in an aqueous solution containing a noble metal precursor and an auxiliary precursor, and then dried and calcined to obtain the catalyst parent material; (2) The catalyst precursor is pre-reduced in a hydrogen-containing atmosphere to obtain a catalyst intermediate; (3) The catalyst intermediate is induced to activate in an atmosphere containing CO and H2S; The noble metal is Pt and / or Pd, and the metal element in the auxiliary precursor is at least one of Fe, Co and Ni.

2. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 1, characterized in that, The sulfur-resistant noble metal-based CO oxidation catalyst forms Pt / Pd-A / AO x / MO x Surface-interface structure, wherein Pt / Pd-A are alloy particles of active components and additives, and are in a sulfur hybrid state, AO x MO is an oxide of an auxiliary metal. x As a carrier.

3. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 1 or 2, characterized in that, Based on the total weight of the sulfur-resistant noble metal-based CO oxidation catalyst, the loading of the active component, calculated as metal element, is 0.1-1 wt%, and the loading of the auxiliary agent, calculated as metal element, is 0.1-3 wt%.

4. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 1, characterized in that, In step (1), the impregnation process is an equal-volume impregnation.

5. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 4, characterized in that, The impregnation process includes a stirring stage and a settling stage. The stirring stage lasts for 0.5-1 hour, and the settling stage lasts for 6-18 hours.

6. The sulfur-resistant noble metal-based CO oxidation catalyst according to any one of claims 1, characterized in that, In step (1), the carrier is pre-cooked before impregnation.

7. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 6, characterized in that, The calcination conditions for the carrier include: a temperature of 400-700℃ and a calcination time of 4-8 hours.

8. The sulfur-resistant noble metal-based CO oxidation catalyst according to any one of claims 1, characterized in that, The carrier has a particle size of 10-500 nm and a specific surface area of ​​60-200 m². 2 / g.

9. The sulfur-resistant noble metal-based CO oxidation catalyst according to any one of claims 1, characterized in that, In step (1), the noble metal precursor is at least one of chloroplatinic acid, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate and palladium acetate.

10. The sulfur-resistant noble metal-based CO oxidation catalyst according to any one of claims 1, characterized in that, In step (1), the auxiliary precursor is at least one of the nitrate, chloride and sulfate of the auxiliary metal, preferably the nitrate of the auxiliary metal.

11. The sulfur-resistant noble metal-based CO oxidation catalyst according to any one of claims 1, characterized in that, In step (1), during the drying process, the drying temperature is 60-90℃ and the drying time is 12-24h; during the calcination process, the calcination temperature is 400-600℃ and the calcination time is 3-6h, and the heating rate is 1-3℃ / min.

12. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 1, characterized in that, In step (2), the hydrogen content in the pre-reduction atmosphere is 5-50% by volume.

13. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 1, characterized in that, In step (2), the hydrogen content in the pre-reduction treatment atmosphere is 5-10% by volume.

14. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 1, characterized in that, The temperature for the pre-reduction treatment is 300-500℃.

15. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 1, characterized in that, In step (3), the atmosphere for inducing activation contains CO, H2S and N2, wherein the CO content is 2-5% by volume, the H2S content is 50-200 ppm, and the N2 content is 95-98% by volume.

16. The sulfur-resistant noble metal-based CO oxidation catalyst according to claim 1, characterized in that, The activation temperature is 200-350℃.

17. The use of the sulfur-resistant noble metal-based CO oxidation catalyst according to any one of claims 1-16 as a catalyst for the carbon monoxide oxidation reaction.

18. The application according to claim 17, characterized in that, The reaction gas used in the carbon monoxide oxidation process contains less than 50 ppm of sulfides.

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