Pt-CeOx / K-Beta molecular sieve catalyst for catalytic oxidation of acetone as well as preparation method and application of Pt-CeOx / K-Beta molecular sieve catalyst
By introducing potassium ions into Beta molecular sieves and optimizing the arrangement of Pt-Ce nanoclusters, the problems of insufficient low-temperature activity and anti-carbon deposition performance of the catalyst were solved, achieving efficient low-temperature catalytic oxidation of acetone and long-term cycle stability, thus reducing industrial energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-17
AI Technical Summary
Existing catalysts suffer from insufficient low-temperature activity, poor recyclability, and poor resistance to carbon deposition during the catalytic oxidation of acetone, leading to decreased catalytic activity and process instability.
Potassium ions were introduced into a Beta molecular sieve containing hydroxyl defects using an ion exchange method. Combined with an equal-volume impregnation method to load Pt and Ce active components, the Pt-Ce nanocluster arrangement was optimized through in-situ activation to form a Pt-CeOx/K-Beta molecular sieve catalyst. This modified the acid environment to improve low-temperature activity and anti-carbon deposition performance.
It achieves efficient catalytic oxidation of acetone under low-temperature conditions, exhibiting excellent cycle stability and anti-carbon deposition performance, and significantly reduces the energy consumption of industrial waste gas treatment systems.
Smart Images
Figure CN121869434A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of air pollution control technology, specifically to a Pt-CeO₂ for the catalytic oxidation of acetone. x / K-Beta molecular sieve catalysts, their preparation methods, and applications. Background Technology
[0002] Acetone (CH3COCH3), a typical volatile organic compound (VOC), is widely used in chemical, pharmaceutical, coating, and electronics industries, and is also a common solvent in printing and adhesive processes. However, acetone has certain toxicity and irritant properties. Its volatilization into the atmosphere not only directly harms the human respiratory and nervous systems, but may also participate in photochemical reactions to form ozone and fine particulate matter (PM2.5), exacerbating regional air pollution problems.
[0003] In acetone waste gas treatment technologies, catalytic oxidation is considered one of the most promising technologies due to its significant advantages such as high treatment efficiency, low energy consumption, and no secondary pollution. Currently, research on acetone catalytic oxidation mainly focuses on noble metal catalysts and transition metal oxide catalysts. In practical applications, low-temperature catalytic activity, recyclability, and anti-carbon deposition properties are key indicators for evaluating their industrial value, directly determining catalyst lifespan, operating costs, and process stability. However, existing catalysts generally suffer from insufficient low-temperature activity. During recycling, high temperatures and atmospheric changes easily trigger the migration and aggregation of noble and transition metal particles, leading to a decrease in catalytic activity. Acetone undergoes side reactions such as cracking and polymerization on the catalyst surface, forming carbon deposits mainly composed of hydrocarbons. These deposits preferentially adsorb onto the catalyst's active sites, simultaneously blocking the carrier pores and hindering effective contact between reactants and active centers, ultimately leading to an irreversible decline in catalytic activity. Therefore, developing a catalyst that combines low-temperature catalytic activity, recyclability, and anti-carbon deposition properties is of great significance. Summary of the Invention
[0004] To address the problems existing in the prior art, the primary objective of this invention is to provide a Pt-CeO₂ for the catalytic oxidation of acetone. x / K-Beta catalyst.
[0005] Another object of the present invention is to provide the above-mentioned Pt-CeO x Application of / K-Beta catalyst in the catalytic oxidation of acetone.
[0006] To achieve the above objectives, the present invention provides the following technical solution: A Pt-CeO for the catalytic oxidation of acetone x The preparation method of the / K-Beta molecular sieve catalyst includes the following steps: The K-Beta molecular sieve was impregnated in a mixed solution of platinum and cerium salts, aged, calcined, and reduced to obtain the Pt-CeO. x / K-Beta molecular sieve.
[0007] This invention involves ion-exchange of potassium ions onto an H-Beta molecular sieve containing hydroxyl defects to obtain a K-Beta molecular sieve; then, Pt and Ce active components are loaded onto the K-Beta molecular sieve through equal-volume impregnation to obtain Pt-CeO, which possesses low-temperature activity, cycle stability, and anti-carbon deposition properties. x / K-Beta molecular sieve catalyst. This invention introduces potassium ions into the molecular sieve framework via ion exchange, significantly reducing Brønsted acid (B acid) and increasing Lewis acid (L acid) in the Beta molecular sieve, thereby altering the Pt-CeO₂ composition. x The acidic environment of the / K-Beta molecular sieve catalyst. The introduction of potassium ions provides a strong adsorption active center for acetone molecules and changes the acid catalytic reaction pathway, significantly improving the catalyst's ability to enrich and convert acetone in the low-temperature range (100~120℃), achieving complete low-temperature conversion of acetone in pharmaceutical / paint industry waste gas.
[0008] Preferably, the preparation method of the K-Beta molecular sieve includes the following steps: S1. A NaH-Beta molecular sieve containing hydroxyl defects is subjected to a first ion exchange with an ammonium salt and a first calcination to obtain an H-Beta molecular sieve; S2. Then, the H-Beta molecular sieve is subjected to a second ion exchange with potassium salt and a second calcination to obtain the K-Beta molecular sieve.
[0009] It should be noted that, after multiple experimental verifications, the K-Beta molecular sieve required for this invention can only be obtained through ion exchange. The synthesis of Beta molecular sieves is a self-assembly process, and Na... + Can be combined with organic template agent TEA + Synergistic effect. Small-sized cationic Na + It can stabilize the double four-membered ring structure in Beta molecular sieves. And K... + The larger ionic radius results in a lower charge density, making it less capable of stabilizing high-curvature or small-sized structural units compared to Na. + Cannot be used with TEA + An effective synergistic guiding effect is formed to promote the formation and growth of Beta crystal nuclei. Therefore, a one-pot hydrothermal synthesis of K-Beta molecular sieves was not achieved in the actual synthesis process.
[0010] More preferably, the method for preparing the NaH-Beta molecular sieve containing hydroxyl defects includes the following steps: Sodium source, aluminum source, water, template agent and silicon source are mixed, hydrothermally heated and calcined to obtain the NaH-Beta molecular sieve containing hydroxyl defects.
[0011] More preferably, the molar ratio of sodium source (calculated as Na2O), aluminum source (calculated as Al2O3), silicon source (calculated as SiO2), template agent, and water is 1.25~1.75:1~1.25:28~32:10~14:550~750.
[0012] More preferably, the mixing time is 2 to 4 hours.
[0013] More preferably, the temperature of the hydrothermal treatment is 160~170°C.
[0014] More preferably, the hydrothermal time is 64-72 hours.
[0015] More preferably, the calcination temperature is 500~600℃.
[0016] More preferably, the calcination time is 6-8 hours.
[0017] More preferably, the sodium source is sodium hydroxide and sodium aluminate.
[0018] More preferably, the aluminum source is at least one of sodium aluminate, aluminum sulfate, aluminum oxide, or aluminum hydroxide.
[0019] More preferably, the aluminum source is sodium aluminate.
[0020] More preferably, the silicon source is at least one of silica sol, atmospheric silica, fumed silica, tetraethyl orthosilicate, or sodium silicate.
[0021] More preferably, the template agent is tetraethylammonium hydroxide (TEAOH).
[0022] More preferably, the temperature of the first ion exchange and / or the second ion exchange is 70~90°C.
[0023] More preferably, the duration of the first ion exchange and / or the second ion exchange is 6 to 8 hours.
[0024] More preferably, the ammonium salt is at least one of ammonium chloride, ammonium nitrate, or ammonium sulfate.
[0025] More preferably, the potassium salt is at least one of potassium nitrate, potassium chloride, or potassium sulfate.
[0026] More preferably, the temperature of the first calcination and / or the second calcination is 500~600℃.
[0027] More preferably, the first calcination and / or the second calcination time is 6 to 8 hours.
[0028] Preferably, the calcination temperature is 300~500℃.
[0029] Preferably, the molar ratio of the platinum salt to the cerium salt is 1:(2~6).
[0030] More preferably, the molar ratio of the platinum salt to the cerium salt is 1:(3~5).
[0031] Preferably, the solution volume of the platinum salt and cerium salt is 0.01~0.03 mL.
[0032] Preferably, the platinum salt is at least one of chloroplatinic acid, platinum nitrate, or platinum chloride and its hydrates.
[0033] Preferably, the cerium salt is at least one of cerium chloride, cerium nitrate, or cerium sulfate and their hydrates.
[0034] Preferably, the mass of the K-Beta molecular sieve is 0.4~0.6g.
[0035] Preferably, the mixing time is 15-45 minutes.
[0036] Preferably, the aging time is 20-30 hours.
[0037] Preferably, the calcination temperature is 300~500℃.
[0038] Preferably, the calcination time is 3-5 hours.
[0039] Preferably, the reduction temperature is 350~450℃.
[0040] Preferably, the reduction time is 2 to 4 hours.
[0041] Preferably, the reducing gas is a gas containing hydrogen.
[0042] More preferably, the reducing gas is at least one of hydrogen, a hydrogen-nitrogen mixture, a hydrogen-argon mixture, or a hydrogen-helium mixture.
[0043] Preferably, the Pt-CeO x The acetone catalytic oxidation reaction was carried out using a K-Beta molecular sieve catalyst, and the reaction was repeated 0 to 8 times to obtain the Pt-CeO. x / K-Beta molecular sieve catalyst.
[0044] This invention employs an in-situ activation method to activate Pt-CeO x / K-Beta molecular sieve catalysts were activated under acetone-catalyzed oxidation conditions. During in-situ activation, on the one hand... Pt-CeO... xThe arrangement of Pt-Ce nanoclusters on the surface and pores of K-Beta molecular sieve catalysts is altered and gradually optimized, continuously enhancing low-temperature oxidation activity and metal-support electronic synergy. On the other hand, acidic sites on the K-Beta molecular sieve promote acetone adsorption, optimizing the initial activation pathway for acetone oxidation. Pt-CeO x / K-Beta molecular sieve catalysts utilize acid-thermal synergy to catalyze and maximize the utilization of active components, resulting in a gradual increase in low-temperature activity during cycling. This strategy not only ensures the anti-sintering properties of Pt nanoparticles but also effectively inhibits the formation of carbon deposits and the deactivation of active components during the reaction, maintaining the long-term cycling stability of the catalyst.
[0045] More preferably, the number of cycles is 1 to 8.
[0046] More preferably, the number of cycles is 2 to 8.
[0047] More preferably, the number of cycles is 3 to 8.
[0048] Preferably, the operation process of the acetone catalytic oxidation reaction is as follows: the temperature is increased to 200-240°C at a heating rate of 2-4°C / min and then cooled down.
[0049] Preferably, the conditions for the acetone-catalyzed oxidation reaction are: an acetone concentration of 900-1100 ppm and a space velocity of 30000-70000 h⁻¹. -1 .
[0050] This invention also protects the above-mentioned Pt-CeO x Application of K-Beta molecular sieve catalysts in the catalytic oxidation of acetone.
[0051] Compared with the prior art, the present invention has the following beneficial effects: This invention combines ion exchange with equal-volume co-impregnation to prepare Pt-CeO. x / K-Beta molecular sieve catalyst. This invention introduces potassium ions into Beta molecular sieves containing hydroxyl defects. The potassium ions precisely introduce potassium into the molecular sieve framework, neutralize Brønsted acid sites, significantly reduce Brønsted acidity, and inhibit coking. Furthermore, the arrangement of Pt-Ce nanoclusters is optimized through in-situ activation. In-situ activation and acid-thermal synergy (acidic pathways on the K-Beta molecular sieve surface and Pt-CeO₂) x The combined action of the interfacial thermocatalytic pathway leads to a strong support-metal synergistic effect between the two active components, Pt-Ce, and the K-Beta molecular sieve surface, resulting in Pt-CeO x / K-Beta molecular sieve catalysts exhibit highly efficient low-temperature catalytic activity, enabling efficient catalytic oxidation of acetone at low temperatures (<150℃), and possess extremely high cycle stability and resistance to carbon deposition.
[0052] The Pt-CeO prepared by this invention x / K-Beta molecular sieve catalysts can achieve complete conversion of acetone below 150℃, and complete conversion can be achieved at around 115℃ after 3 cycles; moreover, the low-temperature catalytic activity gradually increases in the first three in-situ activation cycles, and maintains stable low-temperature catalytic activity in the last five in-situ cycles.
[0053] The preparation method and in-situ activation strategy of this invention effectively suppress carbon deposition and deactivation of active components during the reaction process, enabling the catalyst to maintain long-term cycle stability under acetone-containing conditions, while avoiding the use of additional adsorption concentration or preheating units, and significantly reducing the energy consumption of industrial waste gas treatment systems. Attached Figure Description
[0054] Figure 1 The graphs show the catalytic oxidation performance of acetone in Examples 2-4.
[0055] Figure 2 The graph shows the catalytic oxidation performance of acetone during the third in-situ cycle of the catalysts in Example 4 and Comparative Examples 1-3.
[0056] Figure 3 The graph shows the catalytic oxidation performance of acetone in 5 in-situ cycles of Example 4.
[0057] Figure 4 This is a comparison chart of carbon deposition on the catalytic reaction bed after three in-situ cycles of Example 4 and Comparative Examples 1 and 2.
[0058] Figure 5 The images are in situ infrared images of Example 1(a) and Comparative Examples 1(c) and 2(b).
[0059] Figure 6 The infrared spectrum (a) and acidity quantification spectrum (b) of pyridine for Example 4 and Comparative Examples 1 and 2 are shown. Detailed Implementation
[0060] The present invention is further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.
[0061] Example 1 This embodiment provides a Pt-CeO x The preparation method of the / K-Beta molecular sieve catalyst includes the following steps: Preparation of S0.Na-Beta: NaOH, NaAlO2, and deionized water were stirred evenly in a beaker according to a ratio of 1.5Na2O:1Al2O3:30SiO2:10TEAOH:550H2O. TEAOH was then added and stirred until homogeneous. Silica sol or fumed silica was then mixed and stirred thoroughly for 3 hours. Subsequently, the mixture was placed in a high-pressure reactor and hydrothermally reacted at 165℃ for 68 hours. After complete cooling, the mixture was removed, centrifuged, washed, and dried. After drying, it was ground and calcined in a muffle furnace at 550℃ for 6 hours to obtain Na-Beta molecular sieves.
[0062] Preparation of S1.H-Beta: Excess ammonium chloride was dissolved in 25 mL of deionized water. 1.0 g of Na-Beta molecular sieve was taken and stirred in a water bath at 80 °C for 6 h. The resulting white emulsion was centrifuged, washed, and dried in an oven at 80 °C for 12 h. The resulting white powder was calcined in a muffle furnace at 550 °C for 6 h to obtain H-Beta molecular sieve material.
[0063] Preparation of S2.K-Beta: 1.0 g of H-Beta molecular sieve material was placed in a solution containing deionized water and excess potassium nitrate (KNO3, 99%), stirred in a water bath at 80 °C for 6 h, centrifuged and washed, placed in an 80 °C forced-air drying oven for 12 h, and then calcined in a muffle furnace at 550 °C for 6 h to obtain K-Beta molecular sieve material.
[0064] S3. Mix 0.02 mL of platinum tetraamminenitrate and 0.02 mL of cerium nitrate hexahydrate solution, with a molar ratio of Pt to Ce of 1:4. Dilute to 0.21 g using deionized water. Place 0.5 g of K-Beta molecular sieve in a beaker and add the mixed solution dropwise into the K-Beta molecular sieve material. Stir for 30 min to obtain an orange-yellow powder. After aging in a dry environment for 25 h, calcine at 400 °C for 4 h in a muffle furnace, then reduce in a tube furnace at 400 °C under a hydrogen-argon atmosphere for 2 h to obtain Pt-CeO. x / K-Beta molecular sieve catalyst.
[0065] Example 2 This embodiment provides a Pt-CeO x / K-Beta molecular sieve catalysts, the preparation methods of which include: Pt-CeO in Example 1 xThe K-Beta molecular sieve catalyst was placed in a fixed-bed reactor for in-situ acetone catalytic activation to simulate actual operating conditions. Acetone reaction gas was introduced at a concentration of 1000 ppm and a mass hourly space velocity (WHSV) of 66000 h⁻¹. -1 The temperature was programmed to rise from 40℃ to 200℃ at a rate of 2℃ / min, and then cooled back to 40℃. This was recorded as the first in-situ cycle, yielding Pt-CeO. x / K-Beta-C1 molecular sieve catalyst.
[0066] Example 3 This embodiment provides a Pt-CeO x / K-Beta molecular sieve catalysts, the preparation methods of which include: Pt-CeO in Example 2 x The K-Beta-C1 molecular sieve catalyst was circulated once according to the treatment method in Example 2, which was recorded as the second in-situ cycle, to obtain Pt-CeO. x / K-Beta-C2 molecular sieve catalyst.
[0067] Example 4 This embodiment provides a Pt-CeO x / K-Beta molecular sieve catalysts, the preparation methods of which include: Pt-CeO in Example 3 x The K-Beta-C2 molecular sieve catalyst was circulated once according to the treatment method in Example 2, which was recorded as the third in-situ cycle, to obtain Pt-CeO. x / K-Beta-C3 molecular sieve catalyst.
[0068] Comparative Example 1 This comparative example provides a Pt-CeO x The H-Beta molecular sieve catalyst differs from Example 1 in that step S2 is omitted in the preparation method; in S3, 0.5g of H-Beta molecular sieve is placed in a beaker, and the mixed solution is added dropwise to the H-Beta molecular sieve material. The rest is the same as in Example 1.
[0069] Comparative Example 2 This comparative example provides a Pt-CeO x The Na-Beta molecular sieve catalyst differs from Example 1 in that steps S1 and S2 are omitted in the preparation method; in S3, 0.5 g of Na-Beta molecular sieve is placed in a beaker, and the mixed solution is added dropwise to the Na-Beta molecular sieve material. The rest is the same as in Example 1.
[0070] Comparative Example 3 This comparative example provides a Pt-CeO xThe Cs-Beta molecular sieve catalyst differs from Example 1 in that, in S2, excess potassium nitrate is replaced with excess cesium chloride (CsCl, 98%); in S3, 0.5 g of Cs-Beta molecular sieve is placed in a beaker, and the mixed solution is added dropwise to the Cs-Beta molecular sieve material. The rest is the same as in Example 1.
[0071] Acetone catalytic oxidation performance test Take 1g of the sample from the examples or comparative examples, compress it into tablets, sieve out 0.05g of the sample (80-100 mesh), and place it in a reaction tube filled with quartz wool. Place the tube in a thermocatalytic evaluation reaction bed for catalytic activity evaluation. The feed gas consists of 1000ppm acetone, 22% O2 (volume fraction), 78% N2 (volume fraction), and high-purity air as the balance gas, with a flow rate of 55 mL / min (corresponding to a WHSV of 66000 h⁻¹). 1 The concentration of acetone was measured using a flame ionization detector (FID), and data were recorded after the reaction reached steady state at each target temperature. The acetone conversion was calculated using the following equation:
[0072] Figure 1 The figures show the catalytic oxidation performance of acetone in Examples 2-4. Examples 2-4 correspond to three in-situ cycles of Example 1, respectively. Figure 1 It can be seen that after three in-situ cycles, the T90 (temperature at which acetone conversion reaches 90%) of the catalyst in Example 4 decreased by approximately 40°C and 20°C compared to the catalysts in Examples 2 and 3, respectively. During the first three cycles, the T90 of the catalyst gradually decreased. This indicates that after multiple cycles of in-situ activation, the Pt-CeO... x The low-temperature catalytic activity of the / K-Beta molecular sieve catalyst is significantly improved.
[0073] Figure 2 This is a graph showing the catalytic oxidation performance of acetone during the third in-situ cycle of the catalysts in Examples 4 and Comparative Examples 1-3. Example 4 corresponds to the third in-situ cycle of Example 1. Figure 1 It can be seen that the catalyst in Comparative Example 1 achieved 90% acetone conversion (T90) at a temperature of 200°C during the third in-situ cycle, while the T90 for Comparative Example 2 was 130°C and for Comparative Example 3 it was 198°C. The T90 for Example 4 was 112°C. This indicates that the catalyst in Pt-CeO4 with H and the three alkali metal ion exchange configurations of Na, K, and Cs... x Pt-CeO prepared by K ion exchange in / Beta molecular sieve catalyst xThe K-Beta molecular sieve catalyst exhibits the best low-temperature catalytic activity and cycling performance. This is because potassium ions neutralize the bronsted acidic sites on the catalyst while retaining the Lewis acidic sites. Specifically, after three cycles, the H-type (Comparative Example 1) and Na-type (Comparative Example 2) molecular sieve catalysts, due to the presence of strong bronsted acidic sites, produce carbon deposits during cycling, leading to a decrease in their low-temperature catalytic activity. In contrast, the K-type molecular sieve catalyst, with its strong bronsted acidic sites neutralized by potassium ions and Pt-CeO2, exhibits superior low-temperature catalytic activity. x During the three in-situ cycles, the clusters aggregate into smaller clusters, exposing a portion of the molecular sieve surface and allowing the acidic pathways on the molecular sieve surface to interact with Pt-CeO. x The thermocatalytic pathways on the clusters work synergistically to achieve efficient catalytic oxidation of acetone without the formation of carbon deposits.
[0074] Figure 3 The graph shows the catalytic oxidation performance of acetone after five in-situ cycles in Example 4 (Example 1 underwent three in-situ cycles followed by five more). Figure 3 It can be seen that the acetone conversion rate remained consistent in Example 4 across 5 in-situ cycles. This demonstrates that the Pt-CeO provided by this invention... x The K-Beta molecular sieve catalyst maintains its catalytic performance after three in-situ activations, exhibiting excellent cycle stability and showing no activity decrease in subsequent repeated cycles.
[0075] Figure 4 This is a comparison of carbon deposition on the catalytic reaction bed after three in-situ cycles in Example 4 and Comparative Examples 1 and 2. As shown in the figure, after three in-situ cycles in Example 1 (corresponding to Example 4), no carbon deposition formed on the catalyst surface. In contrast, after three in-situ cycles in Comparative Examples 2 and 3, the catalysts were black, and a large amount of carbon deposition formed on the catalyst surface. The comparison demonstrates that the Pt-CeO prepared by this invention… x / K-Beta molecular sieve catalysts exhibit excellent resistance to carbon deposition during cycling.
[0076] Figure 5 The images show in-situ infrared spectroscopy (IR) images of Examples 1(a) and Comparative Examples 1(c) and 2(b) (the orange dashed lines in the images represent acetone). As can be seen from the images, the catalyst in Example 4 did not produce any carbon deposits during the reaction, while Comparative Examples 1 and 2 showed carbon deposits at 2967 cm⁻¹. -1 2931cm -1 and 2877cm -1 The appearance of a vibration peak indicates that Comparative Examples 1 and 2 produced a large amount of carbon deposits. This further illustrates the Pt-CeO₂ phenomenon. xThe K ions in the / K-Beta molecular sieve catalyst can neutralize the Bronsted acidic sites, effectively inhibiting the formation of carbon deposits in the catalyst and giving the catalyst excellent anti-carbon deposition performance.
[0077] Figure 6 The figures show the pyridine infrared spectrum (a) and acidity quantification spectrum (b) for Example 4 and Comparative Examples 1 and 2. As can be seen from the figures, the catalyst in Example 4 has almost no Bronsted acidic sites, while the catalysts in Comparative Examples 1 and 2 have a large number of Bronsted acidic sites, a result consistent with the previous findings.
[0078] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A Pt-CeO₂ for the catalytic oxidation of acetone x / K-Beta molecular sieve catalyst, characterized in that... Its preparation method includes the following steps: K-Beta molecular sieves were impregnated in a mixed solution of platinum and cerium salts, aged, calcined, and reduced to obtain Pt-CeO. x / K-Beta molecular sieve catalyst.
2. The catalyst according to claim 1, characterized in that, The preparation method of the K-Beta molecular sieve includes the following steps: S1. A NaH-Beta molecular sieve containing hydroxyl defects is subjected to a first ion exchange with an ammonium salt and a first calcination to obtain an H-Beta molecular sieve. S2. Then, the H-Beta molecular sieve is subjected to a second ion exchange with potassium salt and a second calcination to obtain the K-Beta molecular sieve.
3. The catalyst according to claim 2, characterized in that, The preparation method of the NaH-Beta molecular sieve containing hydroxyl defects includes the following steps: Sodium hydroxide, aluminum source, water, template agent and silicon source are mixed, hydrothermally heated and calcined to obtain the NaH-Beta molecular sieve containing hydroxyl defects.
4. The catalyst according to claim 2, characterized in that, The duration of the first ion exchange and / or the second ion exchange is 6 to 8 hours.
5. The catalyst according to claim 1, characterized in that, The molar ratio of the platinum salt to the cerium salt is 1:(2~6).
6. The catalyst according to claim 1, characterized in that, The preparation method of the catalyst further includes: preparing the Pt-CeO x The acetone catalytic oxidation reaction was carried out using a K-Beta molecular sieve catalyst, and the reaction was repeated 0 to 8 times to obtain the Pt-CeO. x / K-Beta molecular sieve catalyst.
7. The catalyst according to claim 6, characterized in that, The number of cycles is 1 to 8.
8. The catalyst according to claim 6, characterized in that, The operation process of the catalytic oxidation reaction of acetone is as follows: the temperature is increased to 200-240℃ at a heating rate of 2-4℃ / min and then cooled down.
9. The catalyst according to claim 6, characterized in that, The conditions for the catalytic oxidation of acetone are: acetone concentration of 900-1100 ppm and space velocity of 30000-70000 h⁻¹. -1 .
10. The Pt-CeO according to any one of claims 1 to 9 x Application of K-Beta molecular sieve catalysts in the catalytic oxidation of acetone.