Preparation method of supported manganese-based catalyst
By preparing and absorbing the aqueous manganese acetate solution on the rice husk, drying and carbonizing, a supportive manganese-based catalyst is prepared, which solves the problem of powdering of the carbon-supported manganese catalyst when reloaded, improves the mechanical strength and reaction efficiency of the catalyst, and is suitable for large-scale production.
Patent Information
- Application Number
- CN202411800255.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-02-28
AI Technical Summary
When the carbon-supported manganese catalyst is re-loaded on the porous skeleton matrix, it is prone to powder, resulting in a decrease in reaction sites and affecting the oxidation efficiency of carbon monoxide.
By preparing a aqueous manganese acetate solution, the rice husk is fully absorbed, and then dried and carbonized to prepare a supported manganese-based catalyst. This method synchronizes the preparation and reload of carbon-supported manganese catalyst, which improves the mechanical strength and porous structure of the catalyst.
The stability of the carbon-supported manganese catalyst and the maintenance of the porous structure are achieved, the efficiency of carbon monoxide oxidation reaction is improved, and the cost saving is sufficient, which is suitable for large-scale production.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of catalysts, and more specifically, to the preparation of catalysts for catalytic oxidation of carbon monoxide, and in particular to a method for preparing a supported manganese-based catalyst. Background Art
[0002] Manganese elements supported on nitrogen-doped carbon materials can be used to catalyze the further oxidation of carbon monoxide to carbon dioxide. (Supported Mn catalysts and the role of different supports in the catalytic oxidation of carbon monoxide - Science Direct [J]. Chemical Engineering Science, 2019, 197: 37-51. DOI: 10.1016 / j.ces.2018.12.006.) Due to the low mechanical strength of the modified carbon material, the carbon-supported manganese catalyst is prone to pulverization and loses its porous properties, which reduces the reaction sites and is not conducive to carbon monoxide passing through the catalyst filler. One solution is to load the carbon-supported manganese catalyst on a porous and inert matrix with high mechanical strength.
[0003] Rice husks contain naturally formed silica skeletons. After acid treatment and burning, a silica matrix with a multi-level pore structure can be obtained. Liu Houfan and others found that if the acid treatment process is eliminated, part of the carbon elements in the rice husk will be retained during the burning process, thus obtaining a porous silica-loaded activated carbon structure. (Liu Houfan, Gan Lu, Li Risheng, et al. Research on a new method for preparing white carbon black from rice husks [J]. Inorganic Salt Industry, 2007, 39(2):3.) In the above technical background, we have invented a method for preparing a supported manganese-based catalyst to solve the problem of carbon-supported manganese material being supported on a porous skeleton matrix. Summary of the invention
[0004] In order to solve the problem of carbon-supported manganese material being further supported on a porous skeleton matrix, the present invention aims to provide a method for preparing a supported manganese-based catalyst.
[0005] The object of the present invention is achieved by the following scheme: A method for preparing a supported manganese-based catalyst comprises the following steps: (1) Prepare manganese acetate aqueous solution.
[0006] (2) After drying, add the rice husks into the manganese acetate solution prepared in step (1) and stir them thoroughly. Allow the rice husks to stand to allow the manganese acetate solution to be fully absorbed by the rice husks.
[0007] (3) Re-drying the wet rice husk obtained in step (2).
[0008] (4) The dried rice husk obtained in step (3) is placed in an air atmosphere and heated to carbonize the rice husk, thereby obtaining a supported manganese-based catalyst.
[0009] In step (2), the ratio of dry rice husk to manganese acetate ranges from 10:1 to 100:1.
[0010] Preferably, rice husks produced in Northeast China are used in step (2).
[0011] Due to the large temperature difference between day and night in Northeast China, the rice husk particles obtained are large and uniform, and the final catalyst particle size is also large, which is conducive to the airflow passing through the catalyst filler. Experiments show that under a fixed heating carbonization program, the greater the mass of manganese acetate contained in the same mass of rice husk, the higher the carbon content. Therefore, the carbon content in the catalyst can be directly controlled by adding different amounts of manganese acetate.
[0012] Advantages of the present invention: (1) In this method, the preparation and reloading of the carbon-supported manganese catalyst can be completed simultaneously, saving costs.
[0013] (2) Rice husk as raw material is a cheap and readily available agricultural by-product, which is conducive to large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 These are photos of rice husks, where the left picture shows the morphology of rice husks without manganese acetate modification, the middle picture shows the mass ratio of dry rice husk to manganese acetate is 100:1, and the right picture shows the mass ratio of dry rice husk to manganese acetate is 10:1. DETAILED DESCRIPTION
[0015] The present invention will be further described below in conjunction with specific examples. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial sources. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.
[0016] Example 1 A supported manganese-based catalyst, wherein the mass ratio of dry rice husk to manganese acetate is 100:1, is prepared according to the following steps: (1) Prepare manganese acetate aqueous solution: add 25 mL of pure water and 0.25 g of manganese acetate into a 100 mL beaker and stir rapidly for 5 minutes to obtain a manganese acetate aqueous solution; (2) Drying the rice husks at 80°C for 24 h, weighing 25 g of dry rice husks and adding them to the manganese acetate solution obtained in step (1), and then adding them to the manganese acetate solution prepared in step (1), and stirring them thoroughly; leaving the rice husks to allow them to fully absorb the manganese acetate solution. When there is no residual manganese acetate solution at the bottom of the beaker, stop stirring and leave the beaker for 4 h to allow the rice husks to fully absorb the manganese acetate solution; (3) placing the wet rice husk obtained in step (2) in a forced air drying oven and drying at 105° C. for 4 h; (4) The dried rice husk obtained in step (3) was transferred into a 100 mL quartz beaker and placed in a muffle furnace in an air atmosphere. The mixture was heated to 500° C. at a heating rate of 4° C. / min and maintained for 3 h to carbonize the rice husk. After cooling, a supported manganese-based catalyst was obtained.
[0017] The obtained supported manganese-based catalyst, the product is as follows Figure 1 As shown in the middle figure.
[0018] Example 2 A supported manganese-based catalyst, wherein the mass ratio of dry rice husk to manganese acetate is 10:1, is prepared according to the following steps: (1) Prepare manganese acetate aqueous solution: add 25 mL of pure water and 2.5 g of manganese acetate into a 100 mL beaker and stir rapidly for 5 minutes to obtain a manganese acetate aqueous solution; (2) Drying the rice husks at 80°C for 24 h, weighing 25 g of dry rice husks and adding them to the manganese acetate solution obtained in step (1), and then adding them to the manganese acetate solution prepared in step (1), and stirring them thoroughly; leaving the rice husks to allow them to fully absorb the manganese acetate solution. When there is no residual manganese acetate solution at the bottom of the beaker, stop stirring and leave the beaker for 4 h to allow the rice husks to fully absorb the manganese acetate solution; (3) placing the wet rice husk obtained in step (2) in a forced air drying oven and drying at 105° C. for 4 h; (4) The dried rice husk obtained in step (3) was transferred into a 100 mL quartz beaker and placed in a muffle furnace in an air atmosphere. The mixture was heated to 500° C. at a heating rate of 4° C. / min and maintained for 3 h to carbonize the rice husk. After cooling, a supported manganese-based catalyst was obtained.
[0019] The obtained supported manganese-based catalyst, the product is as follows Figure 1 As shown in the right figure.
[0020] The above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.
Claims
1. A method for preparing a supported manganese-based catalyst, characterized in that: The steps include: (1) Prepare an aqueous solution of manganese acetate; (2) drying the rice husks and adding them to the manganese acetate solution prepared in step (1), and stirring them thoroughly; allowing the rice husks to fully absorb the manganese acetate solution to a ratio of 10:1 to 100:1; (3) re-drying the wet rice husk obtained in step (2); (4) The dried rice husk obtained in step (3) is placed in an air atmosphere and heated to carbonize the rice husk, thereby obtaining a supported manganese-based catalyst.
2. A method for preparing a supported manganese-based catalyst according to claim 1, characterized in that: The rice husk is rice husk produced in Northeast China.
3. A method for preparing a supported manganese-based catalyst according to claim 1 or 2, characterized in that: The mass ratio of dry rice husk to manganese acetate is 100:1, and the preparation is carried out according to the following steps: (1) Prepare manganese acetate aqueous solution: add 25 mL of pure water and 0.25 g of manganese acetate into a 100 mL beaker and stir rapidly for 5 minutes to obtain a manganese acetate aqueous solution; (2) Drying the rice husks at 80°C for 24 h, weighing 25 g of dry rice husks and adding them to the manganese acetate solution obtained in step (1), and then adding them to the manganese acetate solution prepared in step (1), and stirring them thoroughly; leaving the rice husks to allow them to fully absorb the manganese acetate solution. When there is no residual manganese acetate solution at the bottom of the beaker, stop stirring and leave the beaker for 4 h to allow the rice husks to fully absorb the manganese acetate solution; (3) placing the wet rice husk obtained in step (2) in a forced air drying oven and drying at 105° C. for 4 h; (4) The dried rice husk obtained in step (3) was transferred into a 100 mL quartz beaker and placed in a muffle furnace in an air atmosphere. The mixture was heated to 500° C. at a heating rate of 4° C. / min and maintained for 3 h to carbonize the rice husk. After cooling, a supported manganese-based catalyst was obtained.
4. A method for preparing a supported manganese-based catalyst according to claim 1 or 2, characterized in that: The mass ratio of dry rice husk to manganese acetate is 10:1, and the preparation is carried out according to the following steps: (1) Prepare manganese acetate aqueous solution: add 25 mL of pure water and 2.5 g of manganese acetate into a 100 mL beaker and stir rapidly for 5 minutes to obtain a manganese acetate aqueous solution; (2) Drying the rice husks at 80°C for 24 h, weighing 25 g of dry rice husks and adding them to the manganese acetate solution obtained in step (1), and then adding them to the manganese acetate solution prepared in step (1), and stirring them thoroughly; leaving the rice husks to allow them to fully absorb the manganese acetate solution. When there is no residual manganese acetate solution at the bottom of the beaker, stop stirring and leave the beaker for 4 h to allow the rice husks to fully absorb the manganese acetate solution; (3) placing the wet rice husk obtained in step (2) in a forced air drying oven and drying at 105° C. for 4 h; (4) The dried rice husk obtained in step (3) was transferred into a 100 mL quartz beaker and placed in a muffle furnace in an air atmosphere. The mixture was heated to 500° C. at a heating rate of 4° C. / min and maintained for 3 h to carbonize the rice husk. After cooling, a supported manganese-based catalyst was obtained.