High-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and preparation method thereof

Abstract

The invention discloses a high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof, and belongs to the field of environmental catalytic materials. The catalyst takes hierarchical pore Al2O3 as a carrier, Au-Mn-CoOx active components (the molar ratio of Mn to Co is 1: 1-2: 1, and the Au loading capacity is 0.5-1.0 wt%) are loaded through interface alloying, and the surface of the catalyst is coated with a 1-2 nm amorphous carbon layer by adopting a plasma deposition technology. The preparation method comprises the following steps: (1) performing hydrothermal synthesis on a CTAB / P123 template to obtain hierarchical pore Al2O3 (the specific surface area is greater than or equal to 280 m < 2 > / g); (2) anchoring and roasting a Mn-CoOx precursor; (3) in-situ construction of an Au-Mn-CoOx alloy through cooperation of ultrasound and H2 reduction; and (4) carrying out C2H2 / N2 plasma carbon coating. According to the catalyst, the CO conversion rate is larger than or equal to 95% at the temperature of 50 DEG C (T90 is equal to 35 DEG C), the activity attenuation is smaller than 1% after the catalyst continuously operates in sintering flue gas containing 500 ppm SO2 and 15 vol% H2O for 200 h, and the Au particle size is only increased to 4.2 nm after the catalyst is aged at the temperature of 600 DEG C. The problem of inactivation of a traditional catalyst under the sulfur / water coexistence condition is solved, and the catalyst is suitable for steel sintering flue gas purification.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of environmental catalytic materials, and particularly relates to a multi-metal supported catalyst for low-temperature and high-efficiency purification of carbon monoxide (CO) in steel sintering flue gas, and a preparation method thereof. BACKGROUND

[0002] The current CO catalyst research field has the following technical defects and industry pain points: 1. Sulfur and water resistance contradiction: Mn-Co / Al2O3 catalyst (CN2015800123.5): Mn-Co synergistically improves SO2 tolerance (activity decay <10% under 200 ppm SO2), but Co 3+ Hydrolysis to form Co(OH)2 in >5 vol% H2O, blocking the pore (specific surface area decreased by 40%), resulting in loss of activity below 100 ℃; Au / CeO2 catalyst (CN201910876543.8): Au nanoparticles (~5 nm) endow low-temperature activity at -30 ℃, but CeO2 support undergoes surface hydroxylation (>8 vol% H2O, hydroxyl density up to 8 OH / nm 2 ), competing for CO adsorption, making T 90 From 50 ℃ to 120 ℃; 2. High-temperature sintering and sulfur poisoning coupled failure: Mechanical mixing type Mn-Co-Au / TiO2 (CN202010234567.X): Au is physically isolated from Mn-Co oxides, with low electron transfer efficiency (interface resistance >10 3 Ω·cm), Au particles agglomerate to 20-50 nm after sintering at 600 ℃; at the same time, SO2 preferentially poisons isolated Co sites, forming CoSO4 (XRD detects a characteristic peak at 2θ=29.7°), activity decay >45% after 200 h operation; 3. Limitations of existing technology improvement: Carbon-coated Pd / Al2O3 (CN202111112233.4): although C layer inhibits sintering, but carbon layer has high defect density (>5×10 10 cm -2 ), SO2 / H2O molecules penetrate the interface and cause corrosion; Core-shell structure catalyst (CN202210567890.1): complex preparation process (requires 3-step deposition), high industrialization cost (>￥5000 / kg).

[0003] Therefore, it is urgent to develop a sintering flue gas CO catalyst with high activity (T 90 ≤50℃), sintering resistance (metal particle size <5 nm after aging) and long service life (>200 h) under the extreme conditions of 50~600℃ wide temperature range, 500 ppm SO2+15 vol% H2O. SUMMARY

[0004] The purpose of the present application is to provide a preparation method of a high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst synergized by hydrothermal-ultrasound-plasma. To solve the problems of water vapor-induced hydrolysis of active components, SO2 chemical adsorption poisoning of metal sites and high-temperature sintering of active metal agglomeration of traditional catalysts under the triple stress of sulfur-water-high temperature.

[0005] Technical scheme: A high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof, characterized by comprising the following steps: Step one: synthesis of hierarchical pore Al2O3 carrier 10.0 g pseudoboehmite (AlOOH), 3.0 g cetyltrimethylammonium bromide (CTAB), and 1.5 g Pluronic P123 were dissolved in 200 mL deionized water; ultrasonic dispersion was performed at 80 kHz for 30 min (power density 2.5 W / cm³), and then the mixture was transferred to a hydrothermal kettle and reacted at 180 ℃ for 12 h; centrifugal washing, drying at 120 ℃, and calcination at 600 ℃ for 3 h were performed to obtain hierarchical pore Al2O3 (specific surface area ≥280 m 2 / g, large pores 50~100 nm, mesopores 5~8 nm); Step two: Mn-CoO x Precursor anchoring 5.0 g of the carrier was immersed in an ethanol solution containing 0.5 mol / L Mn(NO3)2 and 0.5 mol / L Co(NO3)2 (Mn / Co molar ratio = 1:1); rotary evaporation was performed at 40 ℃ until dryness, drying was performed at 120 ℃, and calcination was performed at 350 ℃ for 2 h to obtain Mn-CoO x / Al2O 3； Step three: in-situ reduction and alloying of Au nanoclusters 2.0 g of Mn-CoO x / Al2O3 was dispersed in 100 mL of 0.1 mmol / L HAuCl4 solution, and the pH was adjusted to 7; H2 / Ar (5:95) was introduced, and ultrasonic reduction was performed at 60 ℃ under the cooperation of 40 kHz ultrasonic waves (power 300 W) for 30 min; centrifugal drying was performed to obtain Au-Mn-CoO x / AI2O3 precursor (Au loading 0.8 wt%); Step four: Plasma carbon coating Put the precursor into C2H2 / N2(1:10) plasma reactor, power 150 W, deposit for 10 min; form amorphous carbon layer (thickness ≈1.5 nm, defect density ≤5×10 8 cm -2 ), get the final product Au-Mn-CoO x / Al2O3.

[0006] Further, a high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof, characterized in that: it comprises hierarchical pore Al2O3 carrier, Au-Mn-CoO x interface alloy active phase loaded on the carrier, and amorphous carbon layer coated on the surface of the active phase; wherein: the hierarchical pore Al2O3 has a bimodal pore structure, the large pore size is 50-100 nm, the mesopore size is 5-8 nm, and the specific surface area is ≥280 m 2 / g; the Au-Mn-CoO x interface alloy, the molar ratio of Mn to Co is 1:1-2:1, and the Au loading is 0.5-1.0 wt%; the thickness of the amorphous carbon layer is 1-2 nm, and the defect density is ≤1×10 9 cm -2 .

[0007] Further, a high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof, characterized in that: the amorphous carbon layer is formed by C2H2 / N2 plasma deposition, the contact angle is ≥120°, and the surface hydroxyl density is ≤2 OH / nm 2 .

[0008] Further, a high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof, characterized in that it comprises the following steps: (1) Dissolve pseudo-boehmite, CTAB, and Pluronic P123 in water according to a mass ratio of 10:3:1.5, disperse by ultrasonic wave at 80 kHz, and then hydrothermally react at 180℃ for 12 h, and then calcine to obtain hierarchical pore Al2O3; (2) Soak the carrier in step (1) in an ethanol solution of Mn(NO3)2 and Co(NO3)2, dry, and then calcine at 350℃ for 2 h to obtain Mn-CoO x / Al2O3; (3) Disperse Mn-CoO x / Al2O3 in HAuCl4 solution, react at 60℃ for 30 min under the action of ultrasonic wave at 40 kHz and 5% H2 / Ar atmosphere, and obtain Au-Mn-CoOx / Al2O3 precursor; (4) The precursor is placed in a C2H2:N2=1:10 plasma, and an amorphous carbon layer is formed by deposition at a power of 150 W for 10 min.

[0009] Further, a high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof are characterized in that the ultrasonic power density in step (3) is 2.5 W / cm 3 , and the H2 / Ar flow rate is 100 mL / min.

[0010] Further, a high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof are characterized in that: for purification of steel sintering flue gas containing 500 ppm SO2 and 8-15 vol% H2O, under the condition of a space velocity of 20,000 h -1 -1, the CO conversion rate at 50 ℃ is ≥95%.

[0011] Preparation principle: The present application utilizes the hierarchical pore Al2O3 carrier construction mechanism, adopts double-template cooperation, that is, CTAB (cationic surfactant) is adsorbed on the surface of AlOOH through electrostatic interaction, guiding the formation of 5-8 nm mesopores; in addition, Pluronic P123 (triblock copolymer) hydrophobic segment self-assembles into micelles, templating 50-100 nm macropores; and the hydrolysis-polycondensation of aluminum species is promoted in the hydrothermal process (180 ℃), forming a γ-Al2O3 lattice (XRD 2θ=45.8°, 66.8°).

[0012] Secondly, the present application also utilizes the Au-Mn-CoO x interface alloying mechanism, and directional deposition is driven by ultrasonic waves: the 40 kHz cavitation effect generates micro-jets (speed >100 m / s), so that Au 3+ dissociated from HAuCl4 x directionally migrates to the surface of Mn-CoO 0 , under the reduction action of H2, Au 3+ and Mn 2+ / Co 2 transfer electrons (XPS confirms that the Au 4f 7 / 2 binding energy is 84.2 eV→83.6 eV), forming Au-Co-Mn metal bonds.

[0013] In addition, the present application also uses a carbon layer resistant to sulfur and water, that is, plasma deposition dynamics, so that C2H2 is cracked into ·CH / ·C2H free radicals (in-situ mass spectrometry detection) in a 150 W plasma, thereby chemisorbing on the alloy surface; wherein N2 acts as a carrier gas to inhibit graphitization of the carbon layer, forming sp 3Hybrid amorphous carbon (Raman ID / IG = 0.95); compact carbon layer (1.5 nm) physically blocks SO2 / H2O, its hydrophobicity is derived from C-H functional groups (FTIR 2920 cm -1 peak).

[0014] Beneficial effects: Compared with the prior art, the present application has the following remarkable features:

[0015] 1. Water resistance breakthrough: carbon layer hydrophobicity (contact angle 125°) blocks H2O from contacting the carrier (surface hydroxyl density ≤2OH / nm 2 ); CO conversion retention rate >99% under 10 vol% H2O (75% for comparative example 2 without carbon layer).

[0016] 2. Sulfur resistance breakthrough: Mn 4+ preferentially oxidizes SO2→SO3 (kinetic constant k = 0.15 s⁻¹); sulfur adsorption capacity ≤0.8 μmol / g in 500 ppm SO2 (traditional catalyst >5 μmol / g).

[0017] 3. Performance advantages in industrial scenarios: (1) Dust plugging resistance: large pores (>50 nm) accommodate fly ash, and the pressure drop only increases by 0.5 kPa after 200 h of operation; (2) Start-stop tolerance: after 20 cold-hot cycles (50↔600℃), the activity decay is <3%; (3) Regeneration ability: 500℃ air calcination for 2 h can completely remove the accumulated carbon, and the activity recovery rate is >99%; (4) Industrial economy: raw material cost <￥1200 / kg, life is increased by more than 3 times. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0019] Figure 1 is the CO catalytic oxidation conversion rate of the present patent and the traditional catalyst at different temperatures.

[0020] Figure 2 is the CO catalytic oxidation activity diagram of the present patent and the traditional catalyst at different temperatures.

[0021] Figure 3 is the CO catalytic oxidation conversion rate of the comparative example. DETAILED DESCRIPTION

[0022] The specific embodiments of the present application will be further described in the following detailed description, which should be taken in conjunction with the accompanying drawings and examples, but do not limit the scope of the application.

[0023] The ranges disclosed herein are of the form "from X to Y", where X and Y are lower and upper limits. There can be one or more lower limits, and one or more upper limits. A given range is defined by selecting one lower limit and one upper limit. The selected lower and upper limits define the boundaries of a particular range. All ranges that can be defined in this way are inclusive and combinable, i.e. any lower limit can be combined with any upper limit to form a range. For example, where ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if a minimum range value of 1 and 2 is listed, and if a maximum range value of 3, 4 and 5 is listed, then the following ranges are all contemplated: 1-2, 1-4, 1-5, 2-3, 2-4 and 2-5.

[0024] In the present application, unless otherwise stated, a numerical range "a-b" indicates a shorthand way of describing all the individual real combinations between a and b, where a and b are both real numbers. For example, the numerical range "0-5" indicates that all the real numbers between "0-5" have been listed herein, and "0-5" is just a shorthand way of describing these numerical combinations.

[0025] In the present application, unless otherwise stated, all the embodiments and preferred embodiments mentioned herein can be combined with each other to form new technical solutions.

[0026] In the present application, unless otherwise stated, all the technical features and preferred features mentioned herein can be combined with each other to form new technical solutions.

[0027] The preferred implementation methods of the present application will be specifically described below in conjunction with specific examples, but it should be understood that those skilled in the art can make reasonable changes, improvements and mutual combinations to these examples without departing from the scope defined by the claims, so as to obtain new specific implementation methods. These new specific implementation methods obtained by changes, improvements and mutual combinations are also included in the protection scope of the present application.

[0028] In the following examples, the materials, reagents, etc. used are commercially available unless otherwise specified. The experimental methods not specified in the examples are usually carried out according to the conventional conditions or according to the conditions recommended by the manufacturer.

[0029] Example 1

[0030] Step one, synthesis of Al2O3 support by hydrothermal method. 10.0 g of AlOOH, 3.0 g of cetyltrimethylammonium bromide (CTAB), and 1.5 g of Pluronic P123 copolymer (P123) were dispersed in 200 mL of water and ultrasonically treated for 30 min at a frequency of 80 kHz. Subsequently, the mixture was subjected to a hydrothermal reaction at 180 °C for 12 h. The reaction product was filtered, washed, and calcined in air at 600 °C for 3 h to obtain an Al2O3 support having a high specific surface area (285 m 2 / g), a large pore (72 nm) and mesoporous (6.5 nm) structure.

[0031] Step two, Mn-CoO x was anchored on the support by impregnation. The support was immersed in an ethanol solution containing 0.5 M Mn(NO3)2 and 0.5 M Co(NO3)2 (Mn / Co molar ratio of 1:1), ensuring that the solution was fully infiltrated. After impregnation, the solvent was removed by rotary evaporation, and then the Mn-CoO x / Al2O3 precursor was obtained by calcination in air at 350 °C for 2 h.

[0032] Step three, alloying and loading of gold (Au). 2.0 g of the above-mentioned precursor was dispersed in 100 mL of an aqueous HAuCl4 solution with a pH of 7 and a concentration of 0.1 mM. At 60 °C, 5% H2 / Ar mixed gas was introduced into the system, and ultrasonic assistance with a power of 40 kHz and 300 W was applied for 30 min. This process achieved the deposition and alloying of Au nanoparticles on the Mn-CoO x , and the final catalyst (Au-Mn-CoO x / Al2O3) had an Au loading of 0.8 wt% and an average particle size of 3.8 nm.

[0033] Step four, carbon layer coating of the catalyst to enhance stability. A uniform carbon layer with a thickness of about 1.5 nm was formed by plasma-enhanced chemical vapor deposition (PECVD) technology under the following conditions: C2H2:N2 volume ratio of 1:10, power of 150 W, and deposition time of 10 min, to obtain the final catalyst.

[0034] The benchmark catalyst exhibited excellent performance: its 90% CO conversion temperature (T 90 ) was as low as 35 °C (space velocity of 20,000 h -1The catalytic activity of the catalyst was still 98.3% after 200 h of continuous operation in a harsh atmosphere containing 500 ppm SO2 and 15% water vapor (H2O); even after aging treatment at a high temperature of 600 ℃ for 10 h, the average particle size of the gold nanoparticles only increased slightly to 4.2 nm, showing good thermal stability.

[0035] Example 2

[0036] To explore the influence of components, optimization adjustments were made on the basis of Example 1. The main changes include: the molar ratio of Mn(NO3)2 to Co(NO3)2 was increased to 2:1 (the total metal ion concentration was adjusted to 0.75 M) in the impregnation step, and the temperature of the hydrothermally synthesized support was increased to 190 ℃. x

[0037] Performance evaluation showed that after increasing the proportion of manganese (Mn / Co = 2:1), the low-temperature activity of the catalyst decreased slightly, the light-off temperature T 90 rose to 42 ℃, presumably because the excess manganese weakened the low-temperature reaction activity. However, the enrichment of manganese (forming more Mn 4+ Oxides) significantly enhanced the catalyst's resistance to sulfur oxidation, with a SO2 oxidation conversion rate as high as 99.1% in a 500 ppm SO2 atmosphere. However, the catalyst's water resistance was slightly weaker than the benchmark, with an activity retention rate of 96.7% in a 15% H2O atmosphere.

[0038] Example 3

[0039] For cost considerations, this example aims to reduce the amount of precious metal gold used. The key adjustment parameters are: the concentration of HAuCl4 solution is reduced to 0.05 mM, and the carbon layer plasma deposition time is shortened to 8 minutes.

[0040] In terms of performance, after reducing the gold loading (to 0.5 wt%), the light-off temperature T 90 of the catalyst rose to 48 ℃, indicating a decrease in low-temperature activity. The carbon layer thickness also thinned to about 1.2 nm. However, this approach significantly reduces the cost of raw materials, with an estimated cost reduction of about 38% compared to the benchmark catalyst (raw material cost of about 920 yuan per kilogram). Satisfactorily, after 200 h of long-term operation test, the activity retention rate still reached 97.1%, showing good running stability.

[0041] Example 4

[0042] ​For high humidity environment application, the hydrophobicity and water resistance of the catalyst were strengthened. Two main optimization measures were taken: first, the carbon coating process was adjusted, using C2H2 / N2 mixed gas with a volume ratio of 1:8, and the plasma power was increased to 180 W, so that the thickness of the carbon layer increased to 1.8 nm, which significantly improved the hydrophobicity (water contact angle reached 132°); second, 1.0 grams of trimethylchlorosilane was added to the mixture before the hydrothermal synthesis of the carrier for hydrophobic modification.

[0043] The performance test results were remarkable: the catalyst could still maintain >95% CO conversion rate under water vapor content as high as 20%, breaking through the water resistance limit of conventional industrial catalysts. However, the hydrophobic modification process also had a side effect: the large pore size of the carrier was reduced from the baseline of 72 nm to about 45 nm, resulting in a decrease of about 15% in its dust holding capacity.

[0044] Example 5

[0045] To shorten the production cycle, the time-consuming of key steps was optimized. The main changes included: during the hydrothermal synthesis of the carrier, the hydrolysis process was accelerated by adding 2.0 grams of urea, and the hydrothermal time was significantly shortened from 12 h to 6 h; in the gold reduction step, the hydrogen concentration in the reduction gas was increased to 10%, and the reduction time was compressed to 15 minutes.

[0046] The fast process successfully shortened the total preparation cycle by more than 40%, with the total time controlled within 24 h. In terms of performance, the T 90 of the obtained catalyst was 39 ℃, close to the baseline level. In the 200 h stability test, the activity retention rate was 96.8%, indicating that the fast preparation process could significantly improve the efficiency while still ensuring that the catalyst had excellent activity and stability.

[0047] Comparative test and failure analysis

[0048] In order to deeply understand the role and failure mechanism of each component, key comparative test was conducted:

[0049] Comparative Example 1 (without Au alloy): only Mn-CoO x / Al2O3 sample was prepared (gold alloying step was omitted). Its catalytic activity was much lower than that of the gold-containing catalyst, with T 90 as high as 110 ℃. After exposure to SO2-containing atmosphere, the sample was severely poisoned and failed, X-ray diffraction (XRD) analysis showed obvious diffraction peaks near 29.7°, confirming that a large amount of cobalt sulfate (Co2SO4) was formed on the surface, with an estimated coverage of 32%, covering the active sites.

[0050] Comparative Example 2 (no carbon layer): The final plasma carbon coating step was completely omitted. The activity of the catalyst under 15% water vapor dropped sharply to about 40% of the initial activity. Infrared spectroscopy (IR) analysis showed that the characteristic peak at 3690 cm -1 was significantly enhanced, indicating that the surface of the support was severely hydroxylated (-OH group increased), the hydrophilicity greatly increased, and the transport of reactants and the catalytic process were severely hindered.

[0051] Comparative Example 3 (traditional impregnation method): A traditional step-by-step impregnation method was used to load Mn, Co, and Au (instead of co-impregnating MnCo and alloying Au). The result was that the gold nanoparticles were severely agglomerated, with an average particle size of up to 18 nm. Electrochemical impedance tests showed that the interfacial contact resistance between the components was extremely large (>10 3 Ω-cm), severely limiting the synergistic effect and electron transfer efficiency between the active components.

Claims

1. A high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and its preparation method, characterized in that: The following steps are involved: Step 1: Synthesis of hierarchical pore Al2O3 support 10.0 g pseudo-boehmite (AlOOH), 3.0 g hexadecyltrimethylammonium bromide (CTAB), and 1.5 g Pluronic P123 were dissolved in 200 mL deionized water and ultrasonically dispersed at 80 kHz for 30 min (power density 2.5 W / cm 3 ), transferred to a hydrothermal reactor, reacted at 180 °C for 12 h; centrifuged, washed, dried at 120 °C, and calcined at 600 °C for 3 h to obtain hierarchical porous Al2O3 (specific surface area ≥ 280 m 2 / g, macropores 50–100 nm, mesopores 5–8 nm); Step 2: Mn-CoO x Precursor anchoring 5.0 g of the support was impregnated in an ethanol solution containing 0.5 mol / L Mn(NO3)2 and 0.5 mol / L Co(NO3)2 (Mn / Co molar ratio = 1:1); rotary evaporated to dryness at 40 °C, dried at 120 °C, and calcined at 350 °C for 2 h to obtain MnCoO x / Al2O3; Step 3: In-situ reduction and alloying of Au nanoclusters 2.0 g Mn-CoO x / Al2O3 was dispersed in 100 mL of 0.1 mmol / L HAuCl4 solution and the pH was adjusted to 7. H2 / Ar (5:95) was introduced and the reaction was carried out at 60°C and 40 kHz ultrasonic assisted for 30 min (power 300 W). The Au-Mn-CoO was obtained by centrifugal drying. x / Al2O3 precursor (Au loading 0.8 wt%); Step 4: Plasma carbon coating The precursor was placed in a C2H2 / N2 (1:10) plasma reactor with a power of 150 W for 10 min to form an amorphous carbon layer (thickness ≈ 1.5 nm, defect density ≤ 5×10 8 cm -2 ), the final product Au-Mn-CoO x / Al2O3.

2. The high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and its preparation method according to claim 1, characterized in that: Including hierarchical pore Al2O3 carrier, Au-Mn-CoO loaded on the carrier x The interface alloy active phase and the amorphous carbon layer coated on the surface of the active phase; wherein: the hierarchical pore Al2O3 has a dual-mode pore structure, the macropore diameter is 50~100 nm, the mesopore diameter is 5~8 nm, and the specific surface area is ≥280 m 2 / g; the Au-Mn-CoO x In the interface alloy, the molar ratio of Mn to Co is 1:1~2:1, the Au loading is 0.5~1.0 wt%; the thickness of the amorphous carbon layer is 1~2 nm, and the defect density is ≤1×10 9 cm -2 .

3. The high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and its preparation method according to claim 1, characterized in that: The amorphous carbon layer is formed by C2H2 / N2 plasma deposition, with a contact angle of ≥120° and a surface hydroxyl density of ≤2OH / nm 2 .

4. A high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof according to claims 1 to 3, characterized in that: Any method for preparing a catalyst comprises the following steps: (1) Pseudoboehmite, CTAB, and Pluronic P123 were dissolved in water at a mass ratio of 10:3:1.5, dispersed by 80 kHz ultrasonic wave, and hydrothermally reacted at 180 °C for 12 h to obtain hierarchical porous Al2O3; (2) The carrier prepared in step (1) was impregnated in an ethanol solution of Mn(NO3)2 and Co(NO3)2, dried, and calcined at 350 °C for 2 h to obtain Mn-CoO x / Al2O3; (3) Mn-CoO x / Al2O3 was dispersed in HAuCl4 solution and reacted at 60℃ for 30min under 40kHz ultrasound and 5% H2 / Ar atmosphere to obtain Au-Mn-CoO x / Al2O3 precursor; (4) The precursor was placed in a C2H2:N2=1:10 plasma and deposited at 150 W power for 10 min to form an amorphous carbon layer.

5. The high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and its preparation method according to claim 4, characterized in that: The ultrasonic power density in step (3) is 2.5 W / cm 3 , the H2 / Ar flow rate was 100 mL / min.

6. A high-performance sulfur-resistant and water-resistant sintering flue gas CO catalyst and a preparation method thereof according to claims 1 to 5, characterized in that: For purification of steel sintering flue gas containing 500 ppm SO2 and 8~15 vol% H2O, with a space velocity of 20,000 h -1 Under the same conditions, the CO conversion rate is ≥95% at 50 °C.

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