Sulfur-tolerant noble metal-based catalyst and monolithic noble metal catalyst, preparation method therefor and use thereof, and treatment method for industrial tail gas containing carbon monoxide

Abstract

The present invention relates to the technical field of CO oxidation catalysts, and in particular relates to a sulfur-tolerant noble metal-based catalyst and a monolithic noble metal catalyst, a preparation method therefor and the use thereof, and a treatment method for industrial tail gas containing carbon monoxide. The catalyst comprises a carrier, and an active component and an auxiliary which are loaded on the carrier, wherein the active element in the active component is at least one noble metal element, and the active metal element in the auxiliary is at least one non-noble metal element. The dispersion degree of the metals in the catalyst is not less than 40%. The active component and part of the auxiliary form sulfur-hybridized alloy particles, and the average particle diameter of the alloy particles is not greater than 2.0 nm; and in the alloy particles, the proportion of the number of noble metal atoms is greater than or equal to 70%, and the proportion of the number of S atoms is less than or equal to 30%. On the basis of the catalyst of the present invention, low-concentration CO catalytic removal technology can be developed, wherein same is applicable to various conditions for the removal of low-concentration carbon monoxide, including the presence of a sulfide, and can reduce the carbon monoxide concentration in tail gas to 50 ppm or below.

Description

Sulfur-resistant noble metal-based catalysts and monolithic noble metal catalysts, their preparation methods and applications; methods for treating industrial carbon monoxide-containing tail gas.

[0001] Cross-references to related applications

[0002] This invention claims the benefit of Chinese Patent Application No. 202411714614.6, filed on November 27, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of CO oxidation catalyst technology, specifically to sulfur-resistant noble metal-based catalysts and monolithic noble metal catalysts, their preparation methods and applications, and methods for treating industrial carbon monoxide-containing tail gas. Background Technology

[0004] 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.

[0005] 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.

[0006] 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.

[0007] CN114210335A discloses the preparation and application of a low-temperature, water- and sulfur-resistant non-precious metal catalyst for carbon monoxide removal. 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⁻¹ 1 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.

[0008] CN111659415A discloses a method for preparing a coupled nanocomposite noble metal catalyst supported on activated alumina. The 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. -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.

[0009] 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

[0010] The purpose of this invention is to improve the catalytic stability of catalysts in the presence of sulfides (such as hydrogen sulfide) for the treatment of tail gas containing low concentrations of CO in industrial production processes, including coal chemical industry.

[0011] To achieve the above objectives, a first aspect of the present invention provides a sulfur-resistant noble metal-based catalyst, comprising a support and an active component and an additive supported on the support, wherein the active element in the active component is at least one of noble metal elements, and the active metal element in the additive is at least one of non-noble metal elements; the metal dispersion in the catalyst is not less than 40%; the active component and a portion of the additive form sulfur-hybridized alloy particles; the average particle diameter of the alloy particles is not greater than 2.0 nm; and in the alloy particles, the proportion of noble metal atoms is ≥70%, and the proportion of sulfur atoms is ≤30%.

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

[0013] (1) The carrier is immersed in an aqueous solution containing a noble metal precursor and an auxiliary precursor, and then dried, calcined and reduced in sequence to obtain a catalyst matrix; the active element in the noble metal precursor is at least one of the noble metal elements, and the active metal element in the auxiliary precursor is at least one of the non-noble metal elements.

[0014] (2) The catalyst matrix is ​​subjected to induced activation treatment in a redox atmosphere; the redox atmosphere contains reducing gas, sulfiding agent and oxygen.

[0015] A third aspect of the present invention provides a sulfur-resistant noble metal-based catalyst prepared by the method described in the second aspect above.

[0016] A fourth aspect of the present invention provides an integral noble metal catalyst comprising a porous structured support and a coating coated on the porous structured support, the coating containing an active catalytic component;

[0017] The active catalytic component is provided by a powder formed from the sulfur-resistant noble metal-based catalyst described in the first or third aspect.

[0018] A fifth aspect of the present invention provides a method for preparing the monolithic noble metal catalyst described in the fourth aspect, the method comprising:

[0019] (1) The porous structured support is contact-mixed with a slurry containing active catalytic components to obtain intermediate I;

[0020] (2) The intermediate I is dried and calcined in sequence to obtain the monolithic noble metal catalyst.

[0021] The sixth aspect of the present invention provides the application of the sulfur-resistant noble metal-based catalyst described in the first or third aspect and the monolithic noble metal catalyst described in the fourth aspect in the catalytic oxidation reaction of CO.

[0022] A seventh aspect of the present invention provides a method for treating tail gas from a coal gasification unit purification unit, the method comprising: introducing tail gas from the coal gasification unit purification unit into a catalytic oxidation reactor containing a CO catalyst for catalytic oxidation reaction.

[0023] The CO catalyst is a sulfur-resistant noble metal-based catalyst as described in the first or third aspect and / or a monolithic noble metal catalyst as described in the fourth aspect.

[0024] The technical solution of the present invention has at least the following advantages:

[0025] (1) Compared with other CO oxidation catalysts, the sulfur-resistant noble metal-based catalyst and / or monolithic noble metal 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.

[0026] (2) Compared with other CO oxidation catalysts, the sulfur-resistant noble metal-based catalyst and / or monolithic noble metal catalyst described in this invention achieves 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.

[0027] (3) The sulfur-resistant noble metal-based catalyst and / or monolithic noble metal catalyst described in this invention have simple composition and preparation methods, low preparation cost, good repeatability, and are suitable for large-scale production. Furthermore, they exhibit high efficiency and stability. Based on the catalyst described in this invention, a low-concentration CO 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 tail gas to below 50 ppm, and can be widely used in tail 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.

[0028] (4) The solution of the present invention can overcome the limitations of existing CO tail gas removal methods and devices, which cannot meet the requirements of no secondary pollution and high removal rate while being applicable to tail gas generated under various working conditions.

[0029] The solution of this invention can remove CO exhaust gas generated under various operating conditions, and has low energy consumption, no secondary pollution, high efficiency, and good stability, which is conducive to achieving CO emission standards and promoting CO removal technology. Attached Figure Description

[0030] Figure 1 is a graph showing the CO conversion rate catalyzed by the PtFe / Al2O3 catalyst in Example 1;

[0031] Figure 2 shows the HRTEM image and selected area electron diffraction (SAED) analysis of the catalyst PtFe / Al2O3 in Example 1;

[0032] Figure 3 is a HAADF-STEM image of the catalyst PtFe / Al2O3 in Example 1;

[0033] Figure 4 is a statistical diagram of the particle size distribution of the PtFe / Al2O3 alloy particles in Example 1;

[0034] Figure 5 is a HAADF-STEM-EDS line scan of an alloy particle in the catalyst PtFe / Al2O3 in Example 1.

[0035] Figure 6 is the XPS spectrum (S2p) of the catalyst PtFe / Al2O3 in Example 1;

[0036] Figure 7 is the XPS spectrum (Fe2p) of the catalyst PtFe / Al2O3 in Example 1;

[0037] Figure 8 is a picture of the actual honeycomb ceramic catalyst;

[0038] Figure 9 is a SEM image of the honeycomb ceramic catalyst;

[0039] Figure 10 shows the XPS spectra (S2p) of the catalyst PtFe / Al2O3 in Comparative Example 1 after different induced activation atmospheres (H2S-CO);

[0040] Figure 11 shows the XPS spectra (S2p) of the catalyst PtFe / Al2O3 in Comparative Example 2 after different induced activation atmospheres (H2S-O2); 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 invention 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 invention refers to the volume percentage of the corresponding component in the total gas volume.

[0045] Unless otherwise specified, the metal dispersion refers to the ratio of the number of metal atoms exposed on the catalyst surface to the total number of metal atoms on the catalyst. The "number of metal atoms exposed on the catalyst surface" can be obtained by selective chemical adsorption, and the "total number of metal atoms on the catalyst" represents the total number of metal atoms in the catalyst, which can be determined by ICP-OES (inductively coupled plasma mass spectrometry) or XRF (X-ray fluorescence spectrometry).

[0046] As previously described, a first aspect of the present invention provides a sulfur-resistant noble metal-based catalyst comprising a support and an active component and an additive supported on the support, wherein the active element in the active component is at least one of noble metal elements, and the active metal element in the additive is at least one of non-noble metal elements; the metal dispersion in the catalyst is not less than 40%; the active component and a portion of the additive form sulfur-hybridized alloy particles; the average particle diameter of the alloy particles is not greater than 2.0 nm; and in the alloy particles, the proportion of noble metal atoms is ≥70%, and the proportion of sulfur atoms is ≤30%.

[0047] Particularly preferably, the percentage of sulfur atoms in the alloy particles is ≤10%.

[0048] Preferably, in the alloy particles, S exists in the form of metal sulfides and / or metal sulfates.

[0049] In a preferred embodiment, the mass content of sulfur in the form of metal sulfate, calculated as elemental sulfur, accounts for 50-80% of the total mass content of sulfides, calculated as elemental sulfur.

[0050] Preferably, in the catalyst, the mass content of sulfur in the form of metal sulfides, calculated as elemental sulfur, accounts for ≥20% of the total mass content of sulfides, calculated as elemental sulfur.

[0051] Preferably, the catalyst has QAS / AO x / MO x Surface-interface structure, where QAS represents sulfur-hybridized alloy particles formed by the active component and additives, and Q represents a noble metal element; AO x It is an oxide of an active metal element in the additive; MO x As a carrier.

[0052] Preferably, the QAS hybrid alloy particles contain reduced-state active noble metal-auxiliary metal alloy particles and sulfur atoms. Particularly preferably, the QAS hybrid alloy particles contain reduced-state Pt-Fe alloy.

[0053] Preferably, AO xIt is a complex of at least two oxides of an active metal element in an additive.

[0054] The sulfur-resistant noble metal-based catalyst of the present invention has a specific surface-interface structure, which enables the catalyst to selectively oxidize sulfur-containing species and achieves excellent sulfur resistance in the carbon monoxide oxidation reaction.

[0055] Preferably, the precious metal element is selected from at least one of Pt, Pd, Ru, Rh, and Au; more preferably, the precious metal element is selected from at least one of Pt, Pd, Ru, and Rh; more preferably, the precious metal element is Pt and / or Pd.

[0056] Preferably, the active metal element in the additive is at least one selected from Fe, Co, Ni, Cu, and Mn; more preferably, the active metal element in the additive is at least one selected from Fe, Co, and Ni.

[0057] Preferably, based on the total weight of the 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%.

[0058] Preferably, the carrier is at least one of titanium dioxide, cerium dioxide, aluminum oxide, and zirconium dioxide.

[0059] Preferably, the average particle size of the carrier is 10nm-500nm, and the specific surface area is 60m². 2 / g-200m 2 / g.

[0060] As previously described, a second aspect of the present invention provides a method for preparing a sulfur-resistant noble metal-based catalyst, the method comprising:

[0061] (1) The carrier is immersed in an aqueous solution containing a noble metal precursor and an auxiliary precursor, and then dried, calcined and reduced in sequence to obtain a catalyst matrix; the active element in the noble metal precursor is at least one of the noble metal elements, and the active metal element in the auxiliary precursor is at least one of the non-noble metal elements.

[0062] (2) The catalyst matrix is ​​subjected to induced activation treatment in a redox atmosphere; the redox atmosphere contains reducing gas, sulfiding agent and oxygen.

[0063] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, in step (2), the volume ratio of reducing gas to oxygen in the redox atmosphere is 1:5 to 20.

[0064] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the redox atmosphere further contains an inert gas.

[0065] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the inert gas is selected from at least one of carbon dioxide, nitrogen, helium, and argon.

[0066] In a preferred embodiment, in the method for preparing a sulfur-resistant noble metal-based catalyst, in step (2), the volume content of the reducing gas in the redox atmosphere is 0.2-2.0%.

[0067] More preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the volume content of oxygen in the redox atmosphere is 1-10%.

[0068] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, in step (2), the volume content of the sulfiding agent in the redox atmosphere is 50-500 ppm.

[0069] In a preferred embodiment, in the method for preparing a sulfur-resistant noble metal-based catalyst, in step (2), the reducing gas is at least one of carbon monoxide, hydrogen, methane, ethylene, acetylene, and propylene, more preferably at least one of carbon monoxide and hydrogen.

[0070] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the sulfiding agent is at least one of hydrogen sulfide, carbonyl sulfide, and sulfur dioxide.

[0071] In a preferred embodiment, in the method for preparing sulfur-resistant noble metal-based catalysts, the temperature of the induced activation treatment in step (2) is 200-350°C.

[0072] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, in step (1), the reduction treatment is carried out in a reducing atmosphere containing hydrogen.

[0073] In a preferred embodiment, in the method for preparing a sulfur-resistant noble metal-based catalyst, in step (1), the volume content of hydrogen in the reducing atmosphere is 5-20%, more preferably 5-10%.

[0074] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, in step (1), the temperature of the reduction treatment is 300-500℃.

[0075] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the reduction treatment time in step (1) is 1-3 hours.

[0076] In a preferred embodiment, in the method for preparing a sulfur-resistant noble metal-based catalyst, in step (1), the impregnation process is an equal-volume impregnation.

[0077] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, in step (1), the impregnation process includes a stirring stage and a settling stage, wherein the stirring stage lasts for 0.5-1 h and the settling stage lasts for 6-18 h.

[0078] In a preferred embodiment, in the method for preparing a sulfur-resistant noble metal-based catalyst, in step (1), the support is pre-calcined before the impregnation is performed.

[0079] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the pre-calcination conditions include: a temperature of 400-700℃ and a calcination time of 4-8h.

[0080] For example, the calcination can be carried out by a programmed temperature rise method, with a temperature rise rate of, for example, 1-10°C / min.

[0081] This invention does not have special requirements for the specific operation of the programmed temperature rise. Those skilled in the art can perform the pre-calcination operation in combination with known techniques in the field. This invention will not be described in detail here, and those skilled in the art should not understand it as a limitation of this invention.

[0082] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the average particle size of the support is 10 nm-500 nm, and the specific surface area is 60 m². 2 / g-200m 2 / g.

[0083] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the support is at least one of titanium dioxide, cerium dioxide, alumina, and zirconium dioxide.

[0084] In a particularly preferred embodiment, the saturated water absorption rate of the carrier is 0.5-1.2 mL / g. Taking 1 g of calcined Al2O3 carrier as an example, the method for determining the saturated water absorption rate of the present invention includes: weighing 1 g (m1) of calcined Al2O3 carrier, adding it to a 5 mL graduated cylinder, compacting it on a flat surface, and reading the densely packed volume as 1 mL (V1). Adding 2 mL (V2) of water, stirring thoroughly, and letting it stand for 12 h. Reading the volume of the mixed liquid as 2.3 mL (V3). The volume can then be determined using the formula... The calculated saturated water absorption rate of the Al2O3 support is 0.7 mL / g.

[0085] In a preferred embodiment, in the method for preparing a sulfur-resistant noble metal-based catalyst, in step (1), the noble metal element is selected from at least one of Pt, Pd, Ru, Rh, and Au; preferably, the noble metal element is selected from at least one of Pt, Pd, Ru, and Rh; more preferably, the noble metal element is Pt and / or Pd.

[0086] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, in step (1), the active metal element in the promoter precursor is at least one of Fe, Co, Ni, Cu, and Mn; more preferably, the active metal element in the promoter precursor is at least one of Fe, Co, and Ni.

[0087] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, the noble metal precursor is selected from at least one of chloroplatinic acid, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate, and palladium acetate.

[0088] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, in step (1), the auxiliary precursor is selected from at least one of the auxiliary metal element's nitrate, chloride, and sulfate, and is preferably a nitrate of the auxiliary metal element.

[0089] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, in step (1), the drying temperature is 60-90℃ and the drying time is 12-24h.

[0090] Preferably, in the method for preparing sulfur-resistant noble metal-based catalysts, 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.

[0091] As previously described, a third aspect of the present invention provides a sulfur-resistant noble metal-based catalyst prepared by the above method.

[0092] As mentioned above, a fourth aspect of the present invention provides an integral noble metal catalyst comprising a porous structured support and a coating coated on the porous structured support, the coating containing an active catalytic component.

[0093] The active catalytic component is provided by a powder formed from the sulfur-resistant noble metal-based catalyst described in the first and / or third aspects.

[0094] Preferably, the specific surface area of ​​the monolithic noble metal catalyst is 1-10 m². 2 / g.

[0095] Preferably, the average thickness of the coating is 1-5 μm.

[0096] Preferably, based on the total weight of the monolithic noble metal catalyst, the content of the porous structured support is 90-99 wt%, and the content of the coating is 1-10 wt%.

[0097] In a preferred embodiment, the porous structured carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier, and alumina honeycomb carrier.

[0098] Particularly preferably, the average particle diameter of the active catalytic component is 1.5 nm to 2 nm.

[0099] As previously stated, a fifth aspect of the present invention provides a method for preparing the monolithic noble metal catalyst described in the fourth aspect, the method comprising:

[0100] (1) The porous structured support is contact-mixed with a slurry containing active catalytic components to obtain intermediate I;

[0101] (2) The intermediate I is dried and calcined in sequence to obtain the monolithic noble metal catalyst.

[0102] Preferably, in step (1), the contact mixing conditions include: a time of 2 min to 1 h and a pressure of 0.1 MPa to 1 MPa.

[0103] In a preferred embodiment, in step (2), the drying temperature is 60-140℃ and the time is 30-180 min; the calcination temperature is 300-500℃ and the time is 60-240 min.

[0104] According to a preferred embodiment, the method further includes the step of preparing the porous structured carrier, comprising: subjecting the raw material structured carrier to acid treatment and calcination in sequence to obtain the porous structured carrier.

[0105] Preferably, the acid treatment operation includes: placing the raw material structured carrier in an acid solution for reflux treatment.

[0106] Preferably, the acid solution is a mixture of nitric acid and an ortho-acid with an H ion molar ratio of 1:1-10, wherein the ortho-acid is sulfuric acid and / or hydrochloric acid.

[0107] Preferably, there are no special requirements for the calcination operation during the preparation of the porous structured support. Those skilled in the art can use conditions known in the art to carry out the operation. This invention will not be described again, and those skilled in the art should not understand it as a limitation of the invention.

[0108] As previously stated, the sixth aspect of the present invention provides the application of the sulfur-resistant noble metal-based catalysts described in the first and / or third aspects, and the monolithic noble metal catalysts described in the fourth aspect, in the catalytic oxidation of CO.

[0109] Preferably, in the CO oxidation reaction, the reactant gas contains sulfides of 200 ppm or less. More preferably, the reactant gas contains sulfides of 50 ppm or less.

[0110] As mentioned above, the seventh aspect of the present invention provides a method for treating tail gas from a coal gasification unit purification unit, the method comprising: introducing tail gas from the coal gasification unit purification unit into a catalytic oxidation reactor containing a CO catalyst for catalytic oxidation reaction.

[0111] The CO catalyst is the sulfur-resistant noble metal-based catalyst described in the first and / or third aspects and / or the monolithic noble metal catalyst described in the fourth aspect.

[0112] This invention collects tail gas from the purification unit of a coal gasification plant (such as tail gas from the top of the liquid nitrogen scrubbing and stripping tower, tail gas from the top of the low-temperature methanol scrubbing and reabsorption tower, etc.), and then sends it into a buffer tank. After passing through a tail gas filter, the gas is mixed with air in a static mixer. The gas then enters or exits the reactor heat exchanger to be preheated by the high-temperature gas after catalytic oxidation. Subsequently, the gas enters the catalytic oxidation reactor, which is equipped with the catalyst described above. In the reactor, CO, methanol, hydrogen, methane, ethane, etc. in the gas are catalytically oxidized into CO2 and water. The catalytic oxidation reaction is exothermic. After catalytic oxidation, the high-temperature gas is cooled by exchanging heat with the unreacted gas in the reactor heat exchanger and then directly released into the atmosphere. An electric heater is installed on the tail gas inlet pipeline to heat the gas during start-up.

[0113] In the above technical solution, preferably, the coal gasification unit is a pulverized coal gasification unit using Shell, Texoco, or SE-Dongfang furnace technology, and the crude syngas is purified by methods such as low-temperature methanol washing technology, liquid nitrogen washing technology, and methanation technology.

[0114] Unless otherwise specified, all raw materials used below are commercially available products.

[0115] The composition and particle size of the obtained catalyst are shown in Table 1.

[0116] Example 1: Preparation of an inherently sulfur-resistant PtFe / Al2O3 catalyst

[0117] Weigh 5.0 g of chloroplatinic acid (H₂PtCl₆) and add it to a 100 mL volumetric flask. Add deionized water to dissolve the solution completely, and then bring the volume to 100 mL. After the solution becomes clear and uniform, let it stand for later use.

[0118] Commercially available γ-phase alumina support (purity above 99.9 wt%, particle size 15-60 nm, specific surface area 100-180 m²) was used. 2 The Al₂O₃ support (g) was placed in a muffle furnace and calcined at 500℃ in air for 4 hours at a heating rate of 3℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for later use. The saturated water absorption rate of the Al₂O₃ support was calculated to be 0.7 mL / g.

[0119] Impregnation: Weigh 2.1g of the prepared chloroplatinic acid solution and add it together with 1.16g of ferric nitrate (Fe(NO3)3·9H2O) into a 50mL beaker. Add 4.9mL of deionized water and stir thoroughly to dissolve. Then, add 10g of pre-calcined Al2O3 support and stir at room temperature (25℃, the same below) for 0.5h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film and let it stand for 12h to obtain the impregnated sample.

[0120] Drying: Take the sample after impregnation and place it in a forced-air drying oven and dry it at 65℃ for 12 hours.

[0121] Calcination: The dried catalyst was placed in a crucible and placed in a muffle furnace under air atmosphere. The temperature was increased from room temperature to 500°C at a heating rate of 2°C / min, and calcined at 500°C for 4 hours. After calcination, the catalyst was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0122] Reduction treatment: The catalyst powder obtained from the previous calcination step is placed in a tubular reactor, and 10% H2 / 90% N2 (volume ratio) is introduced. The temperature is increased to 500℃ at a programmed heating rate of 2℃ / min, and then kept at a constant temperature for 1h for reduction treatment. Subsequently, the temperature is reduced to 350℃ under the protection of reducing gas.

[0123] Induction activation treatment: The catalyst reduced in the previous step is placed in a tubular reactor, and the gas is switched to an atmosphere of 1.0% CO, 0.01% H2S, 5% O2 and 93.99% N2 (volume ratio) for induction activation for 10 hours.

[0124] A sulfur-resistant noble metal-based catalyst, named CAT-A1, was obtained. The high-resolution transmission electron microscopy (HRTEM) characterization of the PtFe / Al2O3 catalyst (CAT-A1) after induced activation is shown in Figure 2. As can be seen from the left part of Figure 2, obvious metal particles are present on the catalyst. Selected area electron diffraction (SAED) analysis and lattice spacing determination of the region containing metal particles revealed distinct diffraction positions representing alumina, Pt-Fe-S metal alloy particles, and iron oxide in the selected metal particles and their surrounding areas, indicating the formation of a special surface-interface structure on the catalyst. This invention confirms through data that this structure is beneficial for improving catalytic reaction activity and stability.

[0125] During the aforementioned induction process, the sulfide content in the reactor outlet exhaust gas was analyzed using gas chromatography. The activation was considered complete when the sulfide content in the exhaust gas was the same as the sulfur content in the induction gas. After activation, the gas mixture was switched to 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 of CO conversion catalyzed by the PtFe / Al2O3 catalyst are shown in Figure 1. As can be seen from Figure 1, the carbon monoxide conversion rate remained above 99% during the 200-hour long-cycle carbon monoxide oxidation reaction.

[0126] ICP-OES analysis revealed that, based on its total weight, the Pt content (calculated as metal element) in the PtFe / Al2O3 catalyst was 0.46 wt% and the Fe content (calculated as metal element) was 1.52 wt%.

[0127] CAT-A1 was characterized using the HAADF-STEM method, and the results are shown in Figure 3. Simultaneously, the particle size distribution of the CAT-A1 alloy particles was statistically analyzed, and the results are shown in Figure 4. Figure 3 shows that the active components on the PtFe / Al2O3 catalyst are relatively uniformly distributed and have small particle sizes. Statistical analysis of the metal particles in Figure 3 is shown in Figure 4. It can be seen that the alloy particles formed on the catalyst are relatively uniform in size, and the average particle size is approximately 1.7 nm. For particle size statistics, when the particles observed by electron microscopy are approximately spherical, the diameter of each particle is measured. For approximately ellipsoidal particles, their major and minor axes are measured separately, and the average value is taken as their diameter. After performing particle size statistics on no fewer than 200 particles, the average particle size is obtained by taking the average value.

[0128] The active metal dispersion on the catalyst was calculated to be 45%. The metal dispersion can be calculated by the ratio of the number of active metal atoms on the catalyst surface to the number of metal atoms on the catalyst. The number of active metal atoms on the surface can be obtained by characterization using hydrogen-oxygen pulsed chemisorption, and the number of metal atoms on the catalyst can be obtained by multiplying the elemental mass content obtained by ICP-OES characterization by Avogadro's constant.

[0129] The catalyst CAT-A1 was characterized using HAADF-STEM-EDS line scanning, and the results are shown in Figure 5. The left part of Figure 5 represents the location of the single metal particles on the catalyst during EDS line scanning; the right part shows the change in elemental atomic content obtained from EDS line scanning as the electron beam scan position changes. Figure 5 shows that in the PtFe / Al2O3 catalyst, the alloy particles after induced activation are in a sulfur hybrid state. The proportions of Pt, Fe, and S in the alloy particles were determined using EDS line scanning; specifically, the atomic ratio in the active particles is Pt:Fe:S = 7:1:2.

[0130] The sulfur element (S2p) on the catalyst CAT-A1 was characterized by XPS analysis, and the results are shown in Figure 6. Figure 6 shows that in the sulfur hybrid alloy particles formed by the active component and the additive, S exists in the form of metal sulfides and metal sulfates. On the catalyst surface, the content of S species existing as metal sulfides is relatively low. Specifically, the sulfur species on the catalyst mainly exist in the form of metal sulfides (163.5 eV) and metal sulfates (168.5 eV), with sulfur existing as metal sulfates accounting for 60% of the total sulfur element mass on the catalyst.

[0131] The iron element (Fe 2p) on the catalyst CAT-A1 was characterized by XPS analysis, and the results are shown in Figure 7. As can be seen from Figure 7, in the composite structure of the catalyst, the promoter metal oxide is a combination of metal oxides with multiple valence states, and the iron species on the catalyst mainly exist in the form of iron oxide.

[0132] Example 2

[0133] This embodiment uses a method similar to that of Embodiment 1, except that:

[0134] Pd was selected as the active component, and commercially available anatase nano-titanium dioxide was selected as the carrier (purity ≥ 99.9 wt%, weight average particle size 10 nm, specific surface area 70–120 m²). 2 / g).

[0135] Add 5.0 g of palladium chloride (PdCl2) to a 100 mL volumetric flask, add deionized water to dissolve it completely, and then bring the volume to 100 mL. After the solution becomes clear and uniform, let it stand for later use.

[0136] Prior to the impregnation step, the titanium dioxide support was placed in a muffle furnace and calcined at 500°C in air for 4 hours. The heating rate was 3°C / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for storage.

[0137] 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 compacted cylinder is recorded as 1mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The saturated water absorption rate of the TiO2 support is calculated to be 0.6mL / g.

[0138] Weigh 1.7 g of the prepared platinum-palladium chloride solution and add it together with 1.16 g of ferric nitrate (Fe(NO3)3·9H2O) into a 50 mL beaker. Add 4.3 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of calcined 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 and let it stand for 12 h to obtain the impregnated sample.

[0139] The rest were the same as in Example 1, and a sulfur-resistant noble metal-based catalyst was obtained, named CAT-A2.

[0140] Example 3

[0141] This embodiment uses a method similar to that of Embodiment 1, except that:

[0142] The additives used are Co and the carrier is zirconium dioxide (ZrO2).

[0143] The nano-zirconia carrier (purity 99.99 wt%, average particle size 10 nm, specific surface area 40–70 m²) purchased from Sinopharm Chemical Reagent Co., Ltd. 2 / g), placed in a muffle furnace, and calcined at 500℃ in air atmosphere for 4 hours. The heating rate was 3℃ / 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 compacted cylinder is read as 0.65mL. Add 2mL of water, stir thoroughly, and let stand for 12h. The saturated water absorption rate of the ZrO2 support is calculated to be 0.35mL / g.

[0145] Weigh 2.1 g of the prepared chloroplatinic acid solution and add it together with 0.74 g of cobalt nitrate (Co(NO3)2·6H2O) into a 50 mL beaker. Add 1.4 mL of deionized water and stir thoroughly to dissolve. Then, add 10 g of calcined 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 and let it stand for 12 h to obtain the impregnated sample.

[0146] The rest were the same as in Example 1, and a sulfur-resistant noble metal-based catalyst was obtained, named CAT-A3.

[0147] Example 4

[0148] This embodiment uses a method similar to that of Embodiment 1, except that:

[0149] Induction activation treatment: The catalyst reduced in the previous step is placed in a tubular reactor, and the gas is switched to an atmosphere of 1.0% CO, 0.01% H2S, 1% O2, and 97.99% N2 (volume ratio) for induction activation for 10 hours.

[0150] The rest were the same as in Example 1, and a sulfur-resistant noble metal-based catalyst was obtained, named CAT-A4.

[0151] Example 5

[0152] This embodiment uses a method similar to that of Embodiment 1, except that:

[0153] Induction activation treatment: The catalyst reduced in the previous step is placed in a tubular reactor, and the gas is switched to an atmosphere of 1.0% CO, 0.01% H2S, 20% O2 and 78.99% N2 (volume ratio) for induction activation for 10 hours.

[0154] The rest were the same as in Example 1, and a sulfur-resistant noble metal-based catalyst was obtained, named CAT-A5.

[0155] Example 6

[0156] This embodiment uses a method similar to that of Embodiment 1, except that:

[0157] Induction activation treatment: The catalyst reduced in the previous step is placed in a tubular reactor, and the gas is switched to a 0.1% CO\0.01% H2S\2% O2\97.89% N2 atmosphere (volume ratio) for induced activation for 10 h.

[0158] The rest were the same as in Example 1, and a sulfur-resistant noble metal-based catalyst was obtained, named CAT-A6.

[0159] Example 7

[0160] This embodiment uses a method similar to that of Embodiment 1, except that:

[0161] Induction activation treatment: The catalyst reduced in the previous step is placed in a tubular reactor, and the gas is switched to an atmosphere of 1.0% CO, 0.005% H2S, 5% O2 and 93.995% N2 (volume ratio) for induction activation for 10 hours.

[0162] The rest were the same as in Example 1, and a sulfur-resistant noble metal-based catalyst was obtained, named CAT-A7.

[0163] Example 8

[0164] This embodiment uses a method similar to that of Embodiment 1, except that:

[0165] Induction activation treatment: The catalyst reduced in the previous step is placed in a tubular reactor, and the gas is switched to an atmosphere of 1.0% CO, 0.05% H2S, 5% O2 and 93.95% N2 (volume ratio) for induction activation for 10 hours.

[0166] The rest were the same as in Example 1, and a sulfur-resistant noble metal-based catalyst was obtained, named CAT-A8.

[0167] Comparative Example 1

[0168] (Same as in Example 1) Weigh 5.0 g of chloroplatinic acid (H2PtCl6) and add it to a 100 mL volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 100 mL. After the solution becomes clear and uniform, let it stand for later use.

[0169] (Same as in Example 1) Commercially available γ-phase alumina support (purity ≥ 99.9 wt%, particle size 15-60 nm, specific surface area 100-180 m²) was used. 2 The Al₂O₃ support (g) was placed in a muffle furnace and calcined at 500℃ in air for 4 hours at a heating rate of 3℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for later use. The saturated water absorption rate of the Al₂O₃ support was calculated to be 0.7 mL / g.

[0170] (Same as Example 1) Impregnation: Weigh 2.1g of the prepared chloroplatinic acid solution and add it together with 1.16g of ferric nitrate (Fe(NO3)3·9H2O) into a 50mL beaker. Add 4.9mL of deionized water and stir thoroughly to dissolve. Then, add 10g of pre-calcined Al2O3 support and stir at room temperature (25℃, the same below) for 0.5h to obtain a slurry-like mixture. Seal the beaker containing the mixture with sealing film and let it stand for 12h to obtain the impregnated sample.

[0171] (Same as Example 1) Drying: Take the sample after impregnation and place it in a forced-air drying oven. Dry at 65°C for 12 hours.

[0172] (Same as Example 1) Calcination: The dried catalyst was placed in a crucible and placed in a muffle furnace under air atmosphere. The temperature was increased from room temperature to 500°C at a heating rate of 2°C / min, and calcined at 500°C for 4 hours. After calcination, the catalyst was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0173] (Same as Example 1) Reduction treatment: The catalyst powder obtained from the previous calcination step was placed in a tubular reactor, and 10% H2 / 90% N2 (volume ratio) was introduced. The temperature was increased to 500°C at a programmable heating rate of 2°C / min, and then kept at a constant temperature for 1 hour for reduction treatment. Subsequently, the temperature was reduced to 350°C under the protection of reducing gas.

[0174] (Different from Example 1) Induction activation treatment: The catalyst reduced in the previous step was placed in a tubular reactor, and the gas was switched to a 1.0% CO\0.01% H2S\98.99% N2 atmosphere (volume ratio) for induction activation for 10 h.

[0175] The catalyst was obtained and named CAT-DA1.

[0176] Comparative Example 2

[0177] (Same as in Example 1) Weigh 5.0 g of chloroplatinic acid (H2PtCl6) and add it to a 100 mL volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 100 mL. After the solution becomes clear and uniform, let it stand for later use.

[0178] (Same as in Example 1) Commercially available γ-phase alumina support (purity ≥ 99.9 wt%, particle size 15-60 nm, specific surface area 100-180 m²) was used. 2 The Al₂O₃ support (g) was placed in a muffle furnace and calcined at 500℃ in air for 4 hours at a heating rate of 3℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for later use. The saturated water absorption rate of the Al₂O₃ support was calculated to be 0.7 mL / g.

[0179] (Same as Example 1) Impregnation: Weigh 2.1g of the prepared chloroplatinic acid solution and add it together with 1.16g of ferric nitrate (Fe(NO3)3·9H2O) into a 50mL beaker. Add 4.9mL of deionized water and stir thoroughly to dissolve. Then, add 10g of pre-calcined Al2O3 support and stir at room temperature (25℃, the same below) for 0.5h to obtain a slurry-like mixture. Seal the beaker containing the mixture with a sealing film and let it stand for 12h to obtain the sample after impregnation.

[0180] (Same as Example 1) Drying: Take the sample after impregnation and place it in a forced-air drying oven. Dry at 65°C for 12 hours.

[0181] (Same as Example 1) Calcination: The dried catalyst was placed in a crucible and placed in a muffle furnace under air atmosphere. The temperature was increased from room temperature to 500°C at a heating rate of 2°C / min, and calcined at 500°C for 4 hours. After calcination, the catalyst was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0182] (Same as Example 1) Reduction treatment: The catalyst powder obtained from the previous calcination step was placed in a tubular reactor, and 10% H2 / 90% N2 (volume ratio) was introduced. The temperature was increased to 500°C at a programmable heating rate of 2°C / min, and then kept at a constant temperature for 1 hour for reduction treatment. Subsequently, the temperature was reduced to 350°C under the protection of reducing gas.

[0183] (Different from Example 1) Induction activation treatment: The catalyst reduced in the previous step was placed in a tubular reactor, and the gas was switched to a 5.0% O2\0.01% H2S\94.99% N2 atmosphere (volume ratio) for induction activation for 10 h.

[0184] The catalyst was obtained and named CAT-DA2.

[0185] Comparative Example 3

[0186] (Same as in Example 1) Weigh 5.0 g of chloroplatinic acid (H2PtCl6) and add it to a 100 mL volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 100 mL. After the solution becomes clear and uniform, let it stand for later use.

[0187] (Same as in Example 1) Commercially available γ-phase alumina support (purity ≥ 99.9 wt%, particle size 15-60 nm, specific surface area 100-180 m²) was used. 2 The Al₂O₃ support (g) was placed in a muffle furnace and calcined at 500℃ in air for 4 hours at a heating rate of 3℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for later use. The saturated water absorption rate of the Al₂O₃ support was calculated to be 0.7 mL / g.

[0188] (Same as Example 1) Impregnation: Weigh 2.1g of the prepared chloroplatinic acid solution and add it together with 1.16g of ferric nitrate (Fe(NO3)3·9H2O) into a 50mL beaker. Add 4.9mL of deionized water and stir thoroughly to dissolve. Then, add 10g of pre-calcined Al2O3 support and stir at room temperature (25℃, the same below) for 0.5h to obtain a slurry-like mixture. Seal the beaker containing the mixture with a sealing film and let it stand for 12h to obtain the sample after impregnation.

[0189] (Same as Example 1) Drying: Take the sample after impregnation and place it in a forced-air drying oven. Dry at 65°C for 12 hours.

[0190] (Same as Example 1) Calcination: The dried catalyst was placed in a crucible and placed in a muffle furnace under air atmosphere. The temperature was increased from room temperature to 500°C at a heating rate of 2°C / min, and calcined at 500°C for 4 hours. After calcination, the catalyst was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0191] (Without reduction treatment) Induction activation treatment: The calcined catalyst is placed in a tubular reactor and heated to 350℃ using a program of 2℃ / min. Then, it is induced and activated for 10h in an atmosphere of 1.0% CO, 0.01% H2S, 5% O2, and 93.99% N2 (volume ratio).

[0192] The catalyst was obtained and named CAT-DA3.

[0193] Comparative Example 4

[0194] (Same as in Example 1) Weigh 5.0 g of chloroplatinic acid (H2PtCl6) and add it to a 100 mL volumetric flask. Add deionized water to dissolve it completely, and then bring the volume to 100 mL. After the solution becomes clear and uniform, let it stand for later use.

[0195] (Same as in Example 1) Commercially available γ-phase alumina support (purity ≥ 99.9 wt%, particle size 15-60 nm, specific surface area 100-180 m²) was used. 2 The Al₂O₃ support (g) was placed in a muffle furnace and calcined at 500℃ in air for 4 hours at a heating rate of 3℃ / min. After calcination, it was allowed to cool naturally to room temperature and then sealed for later use. The saturated water absorption rate of the Al₂O₃ support was calculated to be 0.7 mL / g.

[0196] (Same as Example 1) Impregnation: Weigh 2.1g of the prepared chloroplatinic acid solution and add it together with 1.16g of ferric nitrate (Fe(NO3)3·9H2O) into a 50mL beaker. Add 4.9mL of deionized water and stir thoroughly to dissolve. Then, add 10g of pre-calcined Al2O3 support and stir at room temperature (25℃, the same below) for 0.5h to obtain a slurry-like mixture. Seal the beaker containing the mixture with a sealing film and let it stand for 12h to obtain the sample after impregnation.

[0197] (Same as Example 1) Drying: Take the sample after impregnation and place it in a forced-air drying oven. Dry at 65°C for 12 hours.

[0198] (Same as Example 1) Calcination: The dried catalyst was placed in a crucible and placed in a muffle furnace under air atmosphere. The temperature was increased from room temperature to 500°C at a heating rate of 2°C / min, and calcined at 500°C for 4 hours. After calcination, the catalyst was allowed to cool naturally to room temperature, removed, and sealed for storage.

[0199] (No reduction or activation induction treatment is performed)

[0200] The catalyst was obtained and named CAT-DA4.

[0201] The products obtained from Comparative Example 1 and Comparative Example 2 were characterized using XPS, and the results are shown in Figures 10 and 11.

[0202] As shown in Figure 10, when Comparative Example 1 was activated by catalyst induction with an atmosphere of 1.0% CO, 0.01% H2S, and 98.99% N2 (volume ratio), the sulfur species on the catalyst mainly existed in the form of metal sulfides and sulfates. The mass of sulfur in each type of sulfide accounted for 68 wt% and 32 wt% of the total sulfur mass, respectively. Unlike Example 1, the mass content of sulfur in the form of metal sulfides exceeded 50%. As shown in Figure 11, when Comparative Example 2 was activated by catalyst induction with an atmosphere of 5.0% O2, 0.01% H2S, and 98.99% N2 (volume ratio), the sulfur species on the catalyst mainly existed in the form of metal sulfates. Unlike Example 1, the mass content of sulfur in the form of metal sulfates exceeded 80%.

[0203] Preparation Example 1: Used to prepare monolithic noble metal catalysts. The catalyst powder in the following monolithic noble metal catalysts is obtained by grinding the catalyst prepared in Example 1 above. The particle size of the obtained powder is 10 μm to 100 μm.

[0204] Commercially available cordierite honeycomb ceramic (200 cpsi, 100 mm × 100 mm × 50 mm) was treated with 2 mol / L nitric acid / sulfuric acid (volume ratio 1:10) at 80°C for 24 h under reflux. After washing with deionized water until the pH reached 7, the ceramic was dried to obtain an acid-treated structured carrier. This acid-treated structured carrier was then calcined at 1000 ml / min airflow and 1000°C to obtain a porous structured carrier.

[0205] Contact mixing: 1.5 g of calcined PtFe / Al2O3 catalyst powder and 500 ml of a mixed solution of cerium nitrate and lanthanum nitrate (concentration of the mixed solution is 1 mol / L, molar ratio of cerium to lanthanum is 1:1) were added to a commercially available alumina slurry and stirred for 3 h at 25 °C and pH 5 to obtain solution 1. The porous structured support was then immersed in solution 1 and allowed to stand for 30 min.

[0206] Drying: After the porous structured carrier is removed, it is purged with a 1MPa high-pressure air knife to remove the residual slurry in the pores. Then, it is placed in a 100℃ forced-air drying oven and dried for 12 hours.

[0207] Calcination: The temperature was increased to 400℃ at a heating rate of 5℃ / min and calcined in air for 6 hours, then cooled naturally to room temperature.

[0208] A monolithic noble metal catalyst was obtained and named CAT-B1.

[0209] Figure 8 shows the physical appearance of CAT-B1, and Figure 9 shows its SEM images. The left side of Figure 9 shows a SEM image of the catalyst sample at 15x magnification, and the right side shows a SEM image of the catalyst sample at 50x magnification. Figures 8 and 9 show that the coating on the upper surface of the honeycomb ceramic catalyst is uniformly distributed and of consistent thickness, effectively covering the inner surface of the honeycomb ceramic.

[0210] Test case

[0211] The performance of the catalyst was evaluated using a gas continuous flow fixed-bed microreactor (6 mm inner diameter) to assess the carbon monoxide catalytic oxidation activity of the prepared catalyst material.

[0212] The catalyst activity evaluation device consists of a gas supply unit, a reactor, and a gas chromatograph. The flow rates of the pretreatment and reaction gases are accurately controlled by a mass flow meter. For the activity test, 1 mL of catalyst is loaded. The catalyst particles are sieved to a size between 20 and 60 mesh and placed in the isothermal zone of the reactor. Simultaneously, quartz sand (20-40 mesh), inert to carbon monoxide oxidation at 400°C, is added to the reaction tube to support the catalyst bed and reduce dead volume within the reactor tube. A type K thermocouple is inserted into the catalyst bed to accurately measure the reaction temperature.

[0213] The evaluation of the monolithic honeycomb ceramic catalyst was conducted on a laboratory fixed-bed microreactor evaluation device. The monolithic honeycomb ceramic catalyst was cut into blocks with dimensions of 50×23×23mm. These blocks were then placed in the isothermal zone of a tubular reactor using a support structure, with the surrounding gaps filled with quartz wool to ensure that the gas flow only within the pores of the honeycomb ceramic catalyst.

[0214] The test reaction gas conditions were: 0.6% CO, 0.01% H2S, 2% O2, and CO2 (volume ratio). The activity evaluation results are shown in Table 2.

[0215] Table 1

[0216] Table 2

[0217] As can be seen from Tables 1 and 2, the sulfur-resistant noble metal-based catalyst and / or monolithic noble metal catalyst of the present invention can stably catalyze the carbon monoxide oxidation reaction in a sulfur-containing reaction atmosphere, and has a low catalytic activity temperature. After a reaction time of 200 h, the CO conversion rate is still maintained at over 99%.

[0218] 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 catalyst, characterized in that, The catalyst contains a support and an active component and an additive supported on the support. The active element in the active component is at least one of noble metal elements, and the active metal element in the additive is at least one of non-noble metal elements. The metal dispersion in the catalyst is not less than 40%. The active component and a portion of the additive form sulfur-hybridized alloy particles. The average particle diameter of the alloy particles is not greater than 2.0 nm. In the alloy particles, the proportion of noble metal atoms is ≥70%, and the proportion of sulfur atoms is ≤30%.

2. The catalyst according to claim 1, characterized in that, In the alloy particles, S exists in the form of metal sulfides and / or metal sulfates.

3. The catalyst according to claim 1 or 2, characterized in that, In the catalyst, the mass content of sulfur in the form of metal sulfate, calculated as elemental sulfur, accounts for 50-80% of the total mass content of sulfides, calculated as elemental sulfur. Preferably, in the catalyst, the mass content of sulfur in the form of metal sulfides, calculated as elemental sulfur, accounts for ≥20% of the total mass content of sulfides, calculated as elemental sulfur.

4. The catalyst according to any one of claims 1-3, characterized in that, This catalyst has QAS / AO x / MO x Surface-interface structure, where QAS represents sulfur-hybridized alloy particles formed by the active component and additives, and Q represents a noble metal element; AO x It is an oxide of an active metal element in the additive; MO x As a carrier; Preferably, the QAS hybrid alloy particles contain reduced-state active noble metal-auxiliary metal alloy particles and sulfur atoms; Preferably, AO x It is a complex of at least two oxides of an active metal element in an additive.

5. The catalyst according to claim 4, characterized in that, The precious metal element is selected from at least one of Pt, Pd, Ru, Rh, and Au; preferably, the precious metal element is selected from at least one of Pt, Pd, Ru, and Rh; more preferably, the precious metal element is Pt and / or Pd. Preferably, the active metal element in the additive is at least one selected from Fe, Co, Ni, Cu, and Mn; more preferably, the active metal element in the additive is at least one selected from Fe, Co, and Ni.

6. The catalyst according to any one of claims 1-5, characterized in that, Based on the total weight of the 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%. Preferably, the carrier is at least one of titanium dioxide, cerium dioxide, aluminum oxide, and zirconium dioxide.

7. A method for preparing a sulfur-resistant noble metal-based catalyst, characterized in that, The method includes: (1) The carrier is immersed in an aqueous solution containing a noble metal precursor and an auxiliary precursor, and then dried, calcined and reduced in sequence to obtain a catalyst matrix; the active element in the noble metal precursor is at least one of the noble metal elements, and the active metal element in the auxiliary precursor is at least one of the non-noble metal elements. (2) The catalyst matrix is ​​subjected to induced activation treatment in a redox atmosphere; the redox atmosphere contains reducing gas, sulfiding agent and oxygen.

8. The method according to claim 7, characterized in that, In step (2), the volume ratio of reducing gas to oxygen in the redox atmosphere is 1:5 to 20; Preferably, the redox atmosphere further contains an inert gas; Preferably, the inert gas is selected from at least one of carbon dioxide, nitrogen, helium, and argon.

9. The method according to claim 7 or 8, characterized in that, In step (2), the volume content of the reducing gas in the redox atmosphere is 0.2-2.0%; Preferably, the volume content of oxygen in the redox atmosphere is 1-10%.

10. The method according to any one of claims 7-9, characterized in that, In step (2), the volume content of the sulfiding agent in the redox atmosphere is 50-500 ppm.

11. The method according to any one of claims 7-10, characterized in that, In step (2), the reducing gas is at least one of carbon monoxide, hydrogen, methane, ethylene, acetylene, and propylene; preferably at least one of carbon monoxide and hydrogen.

12. The method according to any one of claims 7-11, characterized in that, The sulfiding agent is at least one of hydrogen sulfide, carbonyl sulfide, and sulfur dioxide.

13. The method according to any one of claims 7-12, characterized in that, In step (2), the temperature of the induced activation treatment is 200-350℃.

14. The method according to any one of claims 7-13, characterized in that, In step (1), the reduction process is carried out in a reducing atmosphere containing hydrogen.

15. The method according to claim 14, characterized in that, In step (1), the volume content of hydrogen in the reducing atmosphere is 5-20%, preferably 5-10%.

16. The method according to any one of claims 7-15, characterized in that, In step (1), the temperature of the reduction treatment is 300-500℃; Preferably, in step (1), the reduction process takes 1-3 hours.

17. The method according to any one of claims 7-16, characterized in that, In step (1), the impregnation process is an equal-volume impregnation.

18. The method according to any one of claims 7-17, characterized in that, In step (1), the impregnation process includes a stirring stage and a settling stage, wherein the stirring stage lasts for 0.5-1 h and the settling stage lasts for 6-18 h.

19. The method according to any one of claims 7-18, characterized in that, In step (1), the carrier is pre-baked before the impregnation is performed; Preferably, the pre-calcination treatment conditions include: a temperature of 400-700℃ and a calcination time of 4-8 hours; Preferably, the average particle size of the carrier is 10nm-500nm, and the specific surface area is 60m². 2 / g-200m 2 / g; Preferably, the carrier is at least one of titanium dioxide, cerium dioxide, aluminum oxide, and zirconium dioxide.

20. The method according to any one of claims 7-19, characterized in that, In step (1), the precious metal element is selected from at least one of Pt, Pd, Ru, Rh and Au; preferably, the precious metal element is selected from at least one of Pt, Pd, Ru and Rh; more preferably, the precious metal element is Pt and / or Pd. Preferably, the active metal element in the additive precursor is at least one selected from Fe, Co, Ni, Cu, and Mn; more preferably, the active metal element in the additive precursor is at least one selected from Fe, Co, and Ni. Preferably, the noble metal precursor is selected from at least one of chloroplatinic acid, platinum chloride, platinum nitrate, platinum acetylacetonate, palladium chloride, palladium nitrate, and palladium acetate; Preferably, in step (1), the auxiliary precursor is selected from at least one of the auxiliary metal element's nitrate, chloride and sulfate, and preferably the auxiliary metal element's nitrate.

21. The method according to any one of claims 7-20, characterized in that, In step (1), during the drying process, the drying temperature is 60-90℃ and the drying time is 12-24h; Preferably, in step (1), during the roasting process, the roasting temperature is 400-600℃, the roasting time is 3-6h, and the heating rate is 1-3℃ / min.

22. A sulfur-resistant noble metal-based catalyst prepared by the method according to any one of claims 7-21.

23. A monolithic noble metal catalyst, characterized in that, The monolithic noble metal catalyst includes a porous structured support and a coating coated on the porous structured support, wherein the coating contains an active catalytic component; The active catalytic component is provided by a powder formed from the sulfur-resistant noble metal-based catalyst according to any one of claims 1-6 and 22.

24. The monolithic noble metal catalyst according to claim 23, characterized in that, The specific surface area of ​​this monolithic noble metal catalyst is 1-10 m². 2 / g; And / or, the thickness of the coating is 1-5 μm.

25. The monolithic noble metal catalyst according to claim 23 or 24, characterized in that, Based on the total weight of the monolithic noble metal catalyst, the content of the porous structured support is 90-99 wt%, and the content of the coating is 1-10 wt%. And / or, the porous structured carrier is selected from at least one of cordierite honeycomb carrier, mullite honeycomb carrier, diamond honeycomb carrier, corundum honeycomb carrier, zirconium corundum honeycomb carrier, quartz honeycomb carrier, nepheline honeycomb carrier, feldspar honeycomb carrier and alumina honeycomb carrier. And / or, the average particle diameter of the active catalytic component is 2nm-3nm.

26. A method for preparing the monolithic noble metal catalyst according to any one of claims 23-25, characterized in that, The method includes: (1) The porous structured support is contact-mixed with a slurry containing active catalytic components to obtain intermediate I; (2) The intermediate I is dried and calcined in sequence to obtain the monolithic noble metal catalyst.

27. The method according to claim 26, characterized in that, In step (1), the contact mixing conditions include: a time of 2 min to 1 h and a pressure of 0.1 to 1 MPa; And / or, in step (2), the drying temperature is 60-140℃ and the time is 30-180min; the calcination temperature is 300-500℃ and the time is 60-240min.

28. The method according to claim 26 or 27, characterized in that, The method also includes the step of preparing the porous structured support, comprising: subjecting the raw material structured support to acid treatment and calcination in sequence to obtain the porous structured support; And / or, the acid treatment operation includes: placing the raw material structured carrier in an acid solution for reflux treatment; And / or, the acid solution is a mixture of nitric acid and an ortho-acid with an H ion molar ratio of 1:1-10, wherein the ortho-acid is sulfuric acid and / or hydrochloric acid.

29. The application of the sulfur-resistant noble metal-based catalyst according to any one of claims 1-6 and 22, and the monolithic noble metal catalyst according to any one of claims 23-25, in the catalytic oxidation of CO.

30. The application according to claim 29, characterized in that, In the CO oxidation reaction, the reactant gas contains less than 200 ppm of sulfides; Preferably, the reaction feed gas contains less than 50 ppm of sulfides.

31. A method for treating industrial exhaust gas containing carbon monoxide, characterized in that, The carbon monoxide-containing tail gas is the tail gas from the purification unit of the coal gasification unit. The method includes: introducing the tail gas from the purification unit of the coal gasification unit into a catalytic oxidation reactor containing a CO catalyst to carry out a catalytic oxidation reaction. The CO catalyst is a sulfur-resistant noble metal-based catalyst according to any one of claims 1-6 and 22 and / or a monolithic noble metal catalyst according to any one of claims 23-25.

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