CO catalytic oxidation catalyst as well as preparation method and application thereof

Abstract

The invention discloses a CO catalytic oxidation catalyst with high catalytic activity and excellent sulfur tolerance as well as a preparation method and application of the CO catalytic oxidation catalyst. The CO catalytic oxidation catalyst has a core-shell structure, the core is Cu3V2O8, and the shell is TiO2. The preparation method of the CO catalytic oxidation catalyst comprises the following steps: (1) preparing Cu3V2O8: step 110, adjusting the pH value of a mixed solution of NH4VO3 and Cu (NO3) 2.3 H2O to be neutral by using ammonia water to obtain a first precursor solution; step 120, collecting, washing and drying the precipitate; step 130, carrying out calcination treatment on the precipitate, so as to obtain Cu3V2O8; (2) preparing a CO catalytic oxidation catalyst: step 210, dropwise adding ammonia water into an absolute ethyl alcohol solution of Cu3V2O8 and butyl titanate under the stirring action to obtain a second precursor solution; step 220, carrying out heat treatment on the second precursor solution; step 230, collecting, washing and drying the precipitate; and step 240, calcining the precipitate to obtain the CO catalytic oxidation catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of CO purification, and in particular to a CO catalytic oxidation catalyst, a preparation method thereof, and applications thereof. Background Art

[0002] Carbon monoxide (CO), a typical product of incomplete combustion, not only exacerbates air pollution but also poses a serious threat to the ecological environment and human health. Among numerous industrial sources, the steel industry is a key contributor to CO emissions. The large amount of CO in tail gas produced during sintering and other processes can reach concentrations as high as 1%, making it a prominent environmental issue that urgently needs to be addressed.

[0003] CO catalytic oxidation technology is considered an effective approach to controlling CO emissions due to its mild reaction conditions and high conversion efficiency. However, in practical applications, sulfur compounds such as SO₂, which are prevalent in sintering flue gas, poison the catalyst, severely affecting its stability and service life, becoming a major obstacle to its engineering promotion. Existing research shows that although catalytic performance and sulfur poisoning resistance can be improved to a certain extent by manipulating catalyst composition, improving the dispersion of active components, and optimizing the support structure, SO₂ will inevitably interact with the catalytic active sites, causing catalyst activity to decrease or even deactivate.

[0004] Therefore, the development of new CO catalytic oxidation catalysts with both high catalytic activity and excellent sulfur tolerance can not only operate stably under harsh sulfur-containing conditions, reducing CO emissions to the environment at the source, but also utilize the heat energy released by the CO oxidation reaction to reduce system energy consumption (such as reducing the additional blast furnace gas consumed by subsequent SCR denitrification). This has significant environmental value and strategic significance for promoting clean production, carbon emission reduction and energy cascade utilization in the steel industry. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a CO catalytic oxidation catalyst having both high catalytic activity and excellent sulfur tolerance, as well as a preparation method and application thereof. The technical solution is as follows:

[0006] The CO catalytic oxidation catalyst has a core-shell structure, with the core being Cu3V2O8 and the shell being TiO2.

[0007] As a further improvement of the above-mentioned CO catalytic oxidation catalyst: the XRD pattern of the CO catalytic oxidation catalyst has characteristic peaks at 15.2°, 18.9°, 27.4°, 32.2° and 37.1° belonging to Cu3V2O8, and characteristic peaks at 25.4°, 37.9°, 48.2°, 54.0°, 55.2° and 62.9° belonging to TiO2.

[0008] The preparation method of a CO catalytic oxidation catalyst comprises the following steps:

[0009] (1) Preparation of Cu3V2O8:

[0010] Step 110, adjusting the pH of a mixed solution of NH4VO3 and Cu(NO3)2·3H2O to neutral with aqueous ammonia to obtain a first precursor solution;

[0011] Step 120, collecting, washing and drying the precipitate;

[0012] Step 130, calcining the precipitate to obtain Cu3V2O8;

[0013] (2) Preparation of CO catalytic oxidation catalyst:

[0014] Step 210, adding ammonia water dropwise to the anhydrous ethanol solution of Cu3V2O8 and butyl titanate under stirring to obtain a second precursor solution;

[0015] Step 220, heat-treating the second precursor liquid;

[0016] Step 230, collecting, washing and drying the precipitate;

[0017] In step 240 , the precipitate is calcined to obtain a CO catalytic oxidation catalyst.

[0018] As a further improvement to the above-mentioned preparation method of the CO catalytic oxidation catalyst, step 110 is specifically as follows:

[0019] Add NH4VO3 powder to distilled water, continue stirring and heat in a water bath to 80°C, keep warm until the powder is completely dissolved, and then cool naturally to obtain an NH4VO3 solution;

[0020] NH4VO3 solution and Cu(NO3)2·3H2O solution were mixed to form a suspension, and then the pH of the suspension was adjusted to neutral with ammonia water. After continuous stirring for 1 hour, the suspension was aged for 2 hours to obtain a first precursor solution.

[0021] As a further improvement of the above-mentioned preparation method of the CO catalytic oxidation catalyst: in step 130, the calcination temperature is 450°C, the calcination time is 3 hours, and the atmosphere is air.

[0022] As a further improvement to the above-mentioned method for preparing the CO catalytic oxidation catalyst: in step 220, the heat treatment temperature is 150°C and the heat treatment time is 12 hours.

[0023] As a further improvement of the above-mentioned preparation method of the CO catalytic oxidation catalyst: in step 240, the calcination temperature is 450°C, the calcination time is 3 hours, and the atmosphere is air.

[0024] The CO purification method uses the above-mentioned CO catalytic oxidation catalyst to treat the flue gas containing CO.

[0025] The CO catalytic oxidation catalyst of the present invention, its preparation method, and its application have the following advantages: The CO catalytic oxidation catalyst of the present invention utilizes a core-shell structure design, which not only reduces interference between SO2 adsorption and the catalytic reaction by inhibiting electron transfer between SO2 and the active site, but also effectively limits direct contact between the active site and SO2 by utilizing the steric hindrance effect of TiO2. Furthermore, it inhibits sulfate deposition on the catalyst surface by inhibiting sulfate formation and promoting sulfate decomposition, effectively improving the catalyst's resistance to SO2 poisoning. Experimental results also show that the core-shell catalyst of the present invention exhibits a lower degree of activity decrease after SO2 pre-poisoning than supported catalysts, demonstrating excellent poisoning resistance.

[0026] The CO catalytic oxidation catalyst of the present invention has a simple preparation method and can be produced on a large scale at a low cost. The resulting catalyst has a large specific surface area, excellent redox performance, and a unique core-shell structure design. This fully utilizes the structural advantages of the catalyst to inhibit internal component migration and aggregation, enhance catalyst stability, and protect active sites, thereby facilitating efficient CO catalytic oxidation reactions and maintaining stable catalytic activity even in high-concentration SO₂ environments. In summary, the present invention improves catalytic performance while effectively solving the deactivation problem of traditional catalysts under SO₂ contamination conditions. It is particularly suitable for CO catalytic oxidation reactions in industries such as steel and chemical engineering, and has strong practicality.

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings that constitute part of this invention are intended to assist in understanding the invention. The contents provided in the drawings and their related descriptions in the present invention may be used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a schematic structural diagram of the catalyst performance evaluation device used in the present invention.

[0030] Figure 2 CO catalytic oxidation performance curves of four catalysts.

[0031] Figure 3 The figure shows the comparison of the conversion temperatures of the four catalysts when the CO conversion rates are 90% and 50%.

[0032] Figure 4 TEM photos, HAADF-TEM photos, element line scan images and EDS photos of Cu3V2O8@TiO2.

[0033] Figure 5 A comparison of the XRD patterns of the four catalysts.

[0034] Figure 6 Comparison of N2 adsorption-desorption isotherms of four catalysts.

[0035] Figure 7 The pore size distribution curves of the four catalysts are compared.

[0036] Figure 8 A comparison of the H2-TPR curves of the four catalysts.

[0037] Figure 9 A comparison of the high-resolution O 1s spectra of XPS of the four catalysts.

[0038] Figure 10 Comparison of high-resolution Cu 2p spectra of XPS of four catalysts.

[0039] Figure 11 Comparison of high-resolution V 2p spectra of XPS of four catalysts.

[0040] Figure 12 Comparison of high-resolution Ti 2p spectra of XPS of four catalysts.

[0041] Figure 13 Comparison of TG curves of four catalysts.

[0042] Figure 14 This is a comparison of the high-resolution S 2p spectra of XPS of Cu3V2O8@TiO2-P and Cu3V2O8 / TiO2-P. DETAILED DESCRIPTION

[0043] The present invention is described clearly and completely below with reference to the accompanying drawings. A person skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention with reference to the accompanying drawings, it should be noted that:

[0044] The technical solutions and technical features provided in each part of the present invention, including the following description, may be combined with each other unless there is any conflict.

[0045] In addition, the embodiments of the present invention described below are generally only part of the embodiments of the present invention, rather than all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts should fall within the scope of protection of the present invention.

[0046] Regarding the terms and units in the present invention: The terms "include", "have" and any variations thereof in the description and claims of the present invention and the related parts are intended to cover non-exclusive inclusions.

[0047] Example

[0048] The preparation method of a CO catalytic oxidation catalyst comprises the following steps:

[0049] (1) Preparation of Cu3V2O8:

[0050] In step 110, NH4VO3 powder is added to distilled water, stirred continuously, and heated in a water bath to 80°C. The mixture is kept warm until the powder is completely dissolved and then cooled naturally to obtain an NH4VO3 solution (concentration: 0.1 mol / L). A certain volume ratio of the NH4VO3 solution (calculated based on the molar ratio of Cu to V in Cu3V2O8) is mixed with a Cu(NO3)2·3H2O solution (concentration: 0.1 mol / L) to form a yellow-green suspension. The pH of the suspension is adjusted to neutral with aqueous ammonia (25% by mass), then stirred continuously for 1 hour and aged for 2 hours to obtain the first precursor solution.

[0051] In step 120, the precipitate in the first precursor solution is filtered, washed three times with distilled water and three times with anhydrous ethanol, and then dried in an oven at 60°C for 12 hours.

[0052] Step 130: Place the dried precipitate in a muffle furnace and calcine at 450°C for 3 hours to obtain Cu3V2O8.

[0053] (2) Preparation of CO catalytic oxidation catalyst:

[0054] In step 210, 6 mL of butyl titanate was added to 120 mL of anhydrous ethanol and stirred continuously for 30 minutes. 3 g of Cu₃V₂O₈ was ground and added to the butyl titanate solution. After sonication for 30 minutes, stirring was continued for 3 hours. While stirring, 6.3 mL of aqueous ammonia was added dropwise to obtain a second precursor solution.

[0055] Step 220: transfer the second precursor solution into a 200 mL reactor and heat-treat it in an oven at 150° C. for 12 h.

[0056] In step 230, the precipitate in the reactor is filtered, washed three times with distilled water and three times with anhydrous ethanol, and dried in an oven at 110° C. for 12 hours.

[0057] In step 240, the dried precipitate is placed in a muffle furnace and calcined at 450° C. for 3 hours to obtain a core-shell CO catalytic oxidation catalyst, hereinafter referred to as Cu 3 V 2 O 8 @TiO 2 .

[0058] Control Example

[0059] Solid TiO2 was added to a Cu(NO3)2·3H2O solution and stirred vigorously for 2 hours to form a turbid solution. NH4VO3 solution was then added to the turbid solution, and the pH was adjusted to neutral with 25% ammonia. Stirring was continued for 1 hour, followed by aging for 2 hours. The precipitate was filtered, washed three times with distilled water and ethanol, and dried in a 60°C oven for 12 hours. The dried precipitate was placed in a muffle furnace and calcined at 450°C for 3 hours to obtain a supported CO oxidation catalyst, denoted as Cu3V2O8 / TiO2.

[0060] Figure 1 This is a schematic diagram of the structure of the catalyst performance evaluation device used in the present invention. The inner diameter of the reactor is 12 mm, and the catalyst loading in the reactor is 3 g. During the test, the total flow rate of the mixed gas output by the mixer is 500 mL / min, and the conversion temperature in the reactor is controlled by the heating furnace to vary within 50 to 400 ° C. The device can test the CO conversion rate with and without SO2, that is, in addition to N2, O2, and CO, the mixed gas can be selected to contain SO2. The CO catalytic oxidation performance of the catalyst is expressed by the CO conversion rate, and its calculation formula is:

[0061] ；

[0062] Where, X CO Indicates CO conversion rate; C COin and C COout are the CO concentrations in the gas at the reactor inlet and outlet, respectively.

[0063] In addition, the device can also be used to simply poison the catalyst to explore the CO catalytic oxidation performance of the poisoned catalyst. In order to test the sulfur tolerance of the catalyst of the present invention, a catalyst treated with SO2 poisoning was prepared. Figure 1The equipment shown was controlled at a bed temperature of 300°C. The mixed gas composition was changed to N2 (carrier gas) and SO2 (250 ppm). After humidification with a humidifier, the moisture content was reduced to 5 vol% H2O. The SO2 poisoning treatment was completed after two hours of aeration. The catalyst of the example after SO2 poisoning treatment was designated as Cu3V2O8@TiO2-P, while the catalyst of the control example after SO2 poisoning treatment was designated as Cu3V2O8 / TiO2-P. The four catalysts were then tested for their CO catalytic oxidation activity and sulfur tolerance.

[0064] Figure 2 CO catalytic oxidation performance curves of four catalysts. Figure 3 The figure shows the comparison of the conversion temperatures of the four catalysts when the CO conversion rates are 90% and 50%.

[0065] like Figure 2-3 As shown in the figure, Cu3V2O8@TiO2 and Cu3V2O8 / TiO2 both exhibit good CO catalytic oxidation activity, and their T 50 (Conversion temperature when CO conversion rate is 50%) are 93°C, 95°C, T 90 (Conversion temperature for 90% CO conversion) are 123°C and 117°C respectively, and the overall oxidation capacity has little difference.

[0066] However, the CO catalytic oxidation activity of Cu3V2O8@TiO2-P and Cu3V2O8 / TiO2-P was tested and it was found that, firstly, the CO catalytic oxidation activity of both catalysts decreased compared with that of fresh catalysts. 50 110°C, 119°C, T 90 148°C and 172°C respectively. Compared with Cu3V2O8@TiO2 and Cu3V2O8 / TiO2, T 50 They rose by 17℃ and 24℃ respectively. 90 They increased by 25°C and 55°C respectively; secondly, compared with the loaded catalyst, the core-shell structure showed a significantly lower decrease in catalytic activity after SO2 poisoning when the original catalytic activity was relatively consistent, showing stronger SO2 tolerance.

[0067] Figure 4 TEM photos, HAADF-TEM photos, element line scan images and EDS photos of Cu3V2O8@TiO2.

[0068] like Figure 4 As shown in the TEM image (a), the TiO2 shell is coated on the Cu3V2O8 surface, showing a clear core-shell interface. Figure 4 (b) HAADF-TEM (high-angle annular dark-field scanning transmission electron microscope) image and the corresponding Figure 4 As shown in the element line scan image (c), along the particle radial direction (0→250nm), the Ti signal is significantly enhanced in the edge area (0-30nm and 220-250nm), while the Cu and V signals are enriched in the core area (30-220nm), confirming that the TiO2 shell completely covers the Cu3V2O8 core. Figure 4 The EDS images (dg) show that the elements are evenly distributed, and Cu and V are mainly concentrated in the core.

[0069] Figure 5 A comparison of the XRD patterns of the four catalysts.

[0070] like Figure 5 As shown in the XRD (X-ray diffraction) pattern of the core-shell catalyst Cu3V2O8@TiO2, the characteristic peaks at 15.2°, 18.9°, 27.4°, 32.2° and 37.1° are attributed to the (100), (-110), (111) and (012) crystal planes of Cu3V2O8 (card number PDF#26-0567), and the characteristic peaks at 25.4°, 37.9°, 48.2°, 54.0°, 55.2° and 62.9° are attributed to the (101), (004), (200), (105), (211) and (204) crystal planes of TiO2 (card number PDF#73-1764), respectively. Combined with the TEM image, it can be seen that anatase TiO2 is uniformly dispersed and covers the Cu3V2O8 core, indicating the successful synthesis of Cu3V2O8@TiO2.

[0071] The XRD pattern of supported Cu3V2O8 / TiO2 shows the characteristic peaks of anatase TiO2. The introduction of Cu3V2O8 does not change its main crystal phase, indicating that Cu3V2O8 is well dispersed in TiO2.

[0072] The catalyst poisoned by sulfidation exhibits the same characteristic peaks as the fresh catalyst without sulfidation. However, the intensity of the characteristic peaks of the catalyst poisoned by sulfidation is reduced compared to the fresh catalyst, which may be due to the partial deposition of sulfate, which leads to the weakening of the crystallinity.

[0073] Figure 6 Comparison of N2 adsorption-desorption isotherms of four catalysts. Figure 7 Table 1 is a table showing the specific surface area, pore volume and average pore diameter of the four catalysts.

[0074] Table 1

[0075]

[0076] like Figure 6-7As shown, the four catalysts before and after sulfidation poisoning all exhibit type IV isotherms with an H3-type hysteresis loop as defined by IUPAC, which indicates that the catalysts have a mesoporous structure.

[0077] As shown in Table 1, Cu3V2O8@TiO2 has the largest specific surface area and pore volume, which facilitates the adsorption and oxidation of CO on the catalyst surface. Compared with the fresh catalyst, the specific surface area, pore volume, and average pore diameter of the sulfide-poisoned catalyst have changed, indicating that the sulfide poisoning products cause physical blockage of the pore structure, resulting in a reduction in specific surface area and, consequently, a reduction in active sites.

[0078] Figure 8 A comparison of the H2-TPR curves of the four catalysts.

[0079] like Figure 8 As shown, the H2-TPR curves of the four catalysts all exhibit two characteristic reduction peaks, which are attributed to Cu 2+ and V 5+ Compared with the sulfide poisoned catalyst, the Cu 2+ The reduction peak temperature is lower, which is consistent with its better CO catalytic oxidation activity. Compared with Cu3V2O8 / TiO2, the V 5+ The reduction peak temperature is lower, indicating that V 5+ More active, which helps protect active sites.

[0080] After the catalyst was poisoned by sulfidation, the peaks of Cu3V2O8@TiO2-P and Cu3V2O8 / TiO2-P both shifted to higher temperatures, indicating a decrease in CO catalytic oxidation activity. 5 The temperature values ​​of the Cu²⁺ reduction peak shifted by 19°C and 11°C, respectively, while the Cu²⁺ reduction peak and V 5 ⁺The temperature values ​​of the reduction peak shifted by 22°C and 16°C, respectively. It can be seen that Cu3V2O8@TiO2-P has a lower shift and better sulfur resistance, which is consistent with the CO catalytic oxidation activity of the core-shell catalyst after sulfur poisoning.

[0081] Figure 9 A comparison of the high-resolution O 1s spectra of XPS of the four catalysts. Figure 10 Comparison of high-resolution Cu 2p spectra of XPS of four catalysts. Figure 11 Comparison of high-resolution V 2p spectra of XPS of four catalysts. Figure 12 Comparison of high-resolution Ti 2p spectra of XPS of four catalysts.

[0082] like Figure 9 As shown in the figure, the O 1s spectra of the four catalysts can be decomposed into surface lattice oxygen (O latt ), adsorbed oxygen (O ads ) and hydroxyl groups (OH - ), the peak positions are 530.0eV, 531.8eV, and 532.6eV respectively. ads and OH - It is active surface oxygen, which is beneficial to the catalytic oxidation reaction of CO. There is no significant difference in the active surface oxygen content between Cu3V2O8@TiO2 and Cu3V2O8 / TiO2, which is consistent with the CO catalytic oxidation activity performance data.

[0083] like Figure 10 As shown in the Cu 2p spectra of the four catalysts, for Cu 2p 2 / 3 orbitals, and two peaks are fitted at about 932.4eV and 934.7eV, corresponding to the Cu + and Cu 2+ .

[0084] like Figure 11 As shown, the V 2p spectra of the four catalysts all show two peaks, located at 517.0~517.4eV and 524.5~524.8eV, corresponding to the V 2p 2 / 3 and V 2p 1 / 2 Compared with Cu3V2O8 / TiO2, both Cu 2p and V 2p of Cu3V2O8@TiO2 shift to higher binding energy, which is attributed to the interaction between the Cu3V2O8 core and the TiO2 shell.

[0085] like Figure 12 As shown, Ti was observed in the Ti 2p spectra of the four catalysts. 4+ The characteristic peaks at 464.4~464.7eV and 458.8~459.2eV correspond to Ti 2p 1 / 2 and Ti 2p 3 / 2 The positions of the characteristic peaks of the supported catalysts before and after sulfidation poisoning did not change significantly, but the Ti 2p peaks of the core-shell catalysts before and after sulfidation poisoning did change significantly. 3 / 2 The characteristic peak shifted from 458.8 to 459.2 eV due to the interaction between SO2 and the TiO2 shell. The inductive effect of the S=O covalent double bond and its strong affinity for electrons attracted Ti electrons, causing a shift in the Ti electron cloud density and an increase in the Ti 2p binding energy. Therefore, it is reasonable to speculate that the TiO2 shell plays a role in preventing the reaction between SO2 and Cu3V2O8, thereby inhibiting the deactivation of the active sites for CO catalytic oxidation.

[0086] Figure 13 Comparison of TG curves of four catalysts. Figure 14 This is a comparison of the high-resolution S 2p spectra of XPS of Cu3V2O8@TiO2-P and Cu3V2O8 / TiO2-P.

[0087] like Figure 13 As shown in the TG curves, the initial weight loss can be attributed to the desorption of water (<200°C), the weight loss between 200 and 400°C is attributed to the desorption of hydroxyl groups on the catalyst surface, and the weight loss between 500 and 650°C is due to the decomposition of sulfate species. The weight loss above 650°C corresponds to the decomposition of Cu3V2O8. The generation of sulfate was observed on the surfaces of both Cu3V2O8@TiO2-P and Cu3V2O8 / TiO2-P.

[0088] like Figure 14 As shown, the characteristic peaks in the S 2p spectrum come from SO4 2+ S in 6+ , indicating that sulfate species were deposited on both the Cu3V2O8@TiO2-P and Cu3V2O8 / TiO2-P surfaces, which is consistent with the TG results. However, the amount of sulfate produced on the Cu3V2O8@TiO2-P (0.31%) surface was less than that on the Cu3V2O8 / TiO2-P (0.40%) surface, indicating that the core-shell structure inhibited sulfate deposition on the catalyst surface.

[0089] In summary, the core-shell structure utilizes the steric hindrance of the TiO2 shell to limit the direct contact between the active sites and SO2. At the same time, the TiO2 shell inhibits the deposition of sulfate on the catalyst surface and improves the resistance to sulfidation poisoning. Ultimately, the activity decrease of the core-shell catalyst after sulfidation poisoning treatment is lower than that of the supported catalyst, which is conducive to the catalytic oxidation reaction of CO.

[0090] In the above characterization, the equipment used is as follows:

[0091] Transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) were performed on a transmission electron microscope (Tecnai G2F20, Thermo Fisher, USA) at an accelerating voltage of 150 kV. The catalyst powder was ultrasonicated in ethanol for 5 minutes and then deposited on a grid.

[0092] X-ray diffraction (XRD) characterization was performed on a Rigaku Ultima IV X-ray diffractometer (Japan) using Cu Kα (λ = 0.15418 nm) radiation. The 2θ scan range was 5–85°, the scan rate was 10° / min, the tube voltage was 40 kV, and the tube current was 40 mA. Data were analyzed using Jade 6.5 software.

[0093] Surface area and pore size analysis: N adsorption-desorption experiments were performed using an automated surface area and pore size distribution analyzer (ASAP 2460, Micromeritics). Samples were degassed under vacuum at 300°C before testing. Surface area, pore size distribution, and pore volume were calculated using the Braeuer-Emmett-Teller (BET) and Barrett-Jayner-Halenda (BJH) methods.

[0094] H2 temperature-programmed reduction (H2-TPR) was performed on a Quzhou Ward VDSord-91i fully automatic chemisorption instrument. A 20 mg sample was pretreated in helium at 300°C for 1 hour, then cooled to 50°C. The temperature was then increased to 650°C at a rate of 5°C / min in a 5% H2 / He reducing gas stream (10 mL / min), and the TCD signal was recorded.

[0095] X-ray photoelectron spectroscopy (XPS) was performed using an XPS analyzer (XSAM-800, KRATOS, UK) using Al Kα radiation (hm = 1486.6 eV), and the obtained spectrum was calibrated to C1s of 284.80 eV.

[0096] Thermogravimetric analysis (TG) was performed using an SDT Q600 thermogravimetric analyzer under a N2 gas flow at a heating rate of 5°C / min over a temperature range of 30–700°C.

[0097] The above describes the relevant contents of the present invention. Based on this description, a person skilled in the art will be able to implement the present invention. Based on the above contents of the present invention, all other embodiments obtained by a person skilled in the art without making any creative efforts should fall within the scope of protection of the present invention.

Claims

1. A CO catalytic oxidation catalyst, characterized by: It has a core-shell structure, with the core being Cu3V2O8 and the shell being TiO2.

2. The CO catalytic oxidation catalyst according to claim 1, wherein: The characteristic peaks of the XRD spectrum of the CO catalytic oxidation catalyst at 15.2°, 18.9°, 27.4°, 32.2° and 37.1° belong to Cu3V2O8, and the characteristic peaks at 25.4°, 37.9°, 48.2°, 54.0°, 55.2° and 62.9° belong to TiO2.

3. The method for preparing the CO catalytic oxidation catalyst according to claim 1 or 2, characterized in that: The following steps are involved: (1) Preparation of Cu3V2O8: Step 110, adjusting the pH of a mixed solution of NH4VO3 and Cu(NO3)2·3H2O to neutral with aqueous ammonia to obtain a first precursor solution; Step 120, collecting, washing and drying the precipitate; Step 130, calcining the precipitate to obtain Cu3V2O8; (2) Preparation of CO catalytic oxidation catalyst: Step 210, adding ammonia water dropwise to the anhydrous ethanol solution of Cu3V2O8 and butyl titanate under stirring to obtain a second precursor solution; Step 220, heat-treating the second precursor liquid; Step 230, collecting, washing and drying the precipitate; In step 240 , the precipitate is calcined to obtain a CO catalytic oxidation catalyst.

4. The method for preparing a CO catalytic oxidation catalyst according to claim 3, wherein: Step 110 is specifically as follows: Add NH4VO3 powder to distilled water, continue stirring and heat in a water bath to 80°C, keep warm until the powder is completely dissolved, and then cool naturally to obtain an NH4VO3 solution; NH4VO3 solution and Cu(NO3)2·3H2O solution were mixed to form a suspension, and then the pH of the suspension was adjusted to neutral with ammonia water. After continuous stirring for 1 hour, the suspension was aged for 2 hours to obtain a first precursor solution.

5. The method for preparing a CO catalytic oxidation catalyst according to claim 3, wherein: In step 130 , the calcination temperature is 450° C., the calcination time is 3 hours, and the atmosphere is air.

6. The method for preparing a CO catalytic oxidation catalyst according to claim 3, wherein: In step 220 , the heat treatment temperature is 150° C. and the heat treatment time is 12 hours.

7. The method for preparing a CO catalytic oxidation catalyst according to claim 3, wherein: In step 240 , the calcination temperature is 450° C., the calcination time is 3 hours, and the atmosphere is air.

8. A method for purifying CO, characterized by: The CO catalytic oxidation catalyst according to claim 1 or 2 is used to treat flue gas containing CO.

Images