Preparation method and application of metal oxide nanocluster supported indium oxide catalyst
By preparing metal oxide nanocluster-supported indium oxide catalysts, the problems of low yield and insufficient activation performance of methanol catalysts in the prior art are solved, and high reaction activity and methanol yield are improved.
Patent Information
- Application Number
- CN202411952385.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-04-04
AI Technical Summary
The existing methanol catalysts have low methanol yield in industrial production and lack the activation performance of hydrogen and carbon dioxide, making it difficult to effectively improve methanol preparation performance.
By preparing metal oxide nanocluster-supported indium oxide catalyst, the metal salt solution and indium oxide are fully mixed by sonication and vacuum rotary evaporation technology to form a catalyst supported by nanoclusters on the surface of indium oxide.
The reaction activity and methanol yield of the catalyst were significantly improved, the carbon dioxide conversion rate was increased by 3-7 times, the methanol yield was increased by 6-12 times, and the reaction stability was good.
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Abstract
Description
Technical field:
[0001] The invention relates to the technical field of catalysts, and in particular to a preparation method and application of a metal oxide nanocluster-loaded indium oxide catalyst. Background technology:
[0002] Methanol is not only an important chemical raw material in industry, but also a fossil alternative fuel, and is considered to be an ideal liquid storage carrier for green hydrogen. Currently, methanol mainly comes from fossil resources. Therefore, preparing methanol by reacting the emitted CO2 with green hydrogen produced from renewable energy is not only conducive to reducing carbon emissions, but also an important way to obtain non-fossil fuels and solve the problem of green hydrogen storage.
[0003] So far, various types of methanol catalysts have been developed, including commercial Cu / ZnO / Al2O3, ZnZr and ZnGa solid solutions. Indium oxide was first proposed in 2013 as a methanol catalyst with excellent performance because it easily forms surface oxygen vacancies that are active for both H2 and CO2 activation. Subsequently, a large number of modification studies have been conducted on indium oxide materials, such as changing the crystal phase and reducing the particle size, to further improve the performance of methanol. However, for industrial production, the methanol yield is still relatively low, and improving the methanol yield remains a long-term task. Cheap transition metal elements such as Ni are abundant in the earth and are cheap and easy to obtain. The surface properties of the catalyst are regulated by loading cheap metals or metal oxides to enhance the activation of hydrogen and increase the number and stability of active oxygen vacancies, thereby improving the performance of methanol. For example, Zhu (ACS Catal., 2021, 11, 11371-11384) et al. prepared nickel-indium oxide alloys by flame sputtering pyrolysis, which effectively improved the performance of methanol. But further improvement is needed. Summary of the invention:
[0004] The purpose of the present invention is to provide a preparation method and application of a metal oxide nanocluster-loaded indium oxide catalyst.
[0005] The present invention is achieved through the following technical solutions:
[0006] A method for preparing a metal oxide nanocluster-loaded indium oxide catalyst, wherein the metal oxide nanocluster in the catalyst has a nanocluster size of 0.5 nm to 2 nm, and the metal oxide nanocluster is loaded on the surface of indium oxide. The method comprises the following steps:
[0007] 1) dissolving a soluble metal salt in a solvent to obtain a metal salt solution, wherein the solvent is a mixture of methanol, ethanol and deionized water, adding indium oxide powder to the metal salt solution, ultrasonicating for 5-60 minutes to prepare a catalyst precursor solution, and then vacuum rotary evaporating at room temperature of 5° C. to 30° C. until the solvent is completely volatilized;
[0008] 2) After the solvent evaporates, the remaining solid is dried and calcined in sequence to obtain the nanocluster-loaded indium oxide catalyst, wherein the drying temperature is 90° C. to 120° C. and the drying time is 10 h to 24 h; the calcination temperature is 250° C. to 400° C. and the calcination time is 2 h to 8 h.
[0009] Preferably, in step 1), the soluble metal salt is selected from one of nickel nitrate, copper acetate, zirconium nitrate and the like.
[0010] Preferably, in step 1), the amount of the metal salt added is calculated based on the corresponding metal of the obtained catalyst, and the loading amount is not more than 20wt%, preferably 3wt%-20wt%.
[0011] The present invention also protects the use of the metal oxide nanocluster-loaded indium oxide catalyst for the fixed bed carbon dioxide hydrogenation to produce methanol reaction.
[0012] The reaction conditions are: reaction temperature between 180℃ and 340℃, H2 / CO2 molar ratio between 1 and 6, reaction pressure between 1.0MPa and 5.0MPa, and volume space velocity between 4500h -1 ~28000h -1 between.
[0013] Preferably, the metal oxide nanocluster-loaded indium oxide catalyst is activated before being used in a fixed bed for the reaction of hydrogenating carbon dioxide to produce methanol. The activation conditions are: in an inert gas atmosphere, the temperature is gradually increased to 150°C to 350°C, and the activation time is between 1h and 4h, wherein the inert gas includes one or more of N2, Ar and He.
[0014] The benefits of the present invention are as follows: the present invention fully mixes a metal salt solution and indium oxide and then performs ultrasonic treatment, then vacuum rotary evaporates the solvent at room temperature, and obtains a metal oxide nanocluster-loaded indium oxide catalyst through drying and calcination. The metal oxide nanocluster in the catalyst is only loaded on the surface of the indium oxide and does not enter the interior of the indium oxide. Moreover, due to the small particle size of the nanocluster and the large exposed specific area, a high atomic utilization rate of the nanocluster is ensured, so that the catalyst exhibits excellent catalytic performance and high reaction activity. The catalyst is applied to the reaction of preparing methanol by hydrogenating carbon dioxide, and the methanol preparation performance is enhanced. The catalyst has the advantages of high reaction activity, high methanol yield, good reaction stability, etc., wherein the carbon dioxide conversion rate is increased by 3-7 times compared with the indium oxide catalyst, and the methanol yield is increased by 6-12 times. Description of the drawings:
[0015] Figure 1 This is the XRD diagram of the nanocluster-supported indium oxide catalyst prepared in Example 1 of the present invention.
[0016] Figure 2 The STEM electron microscope and EDX element surface scanning distribution map of the nanocluster-loaded indium oxide catalyst prepared in Example 1 of the present invention, wherein A is the STEM image, and B, C, and D are the combined image of nickel and indium elements in the EDX element surface scanning distribution map results and the surface scanning element distribution maps of nickel and indium respectively. Specific implementation method:
[0017] The following is a further description of the present invention, rather than a limitation of the present invention.
[0018] Embodiment 1:
[0019] First, 0.468g of nickel nitrate hexahydrate was dissolved in a mixture of 20mL of methanol, ethanol and deionized water in a round-bottom flask. Then 2g of indium oxide powder was added to the solution, followed by 30 minutes of ultrasonic treatment. The flask was then connected to a vacuum rotary evaporator and evaporated at room temperature at a rotation speed of 20rpm until all the solvent evaporated. The solid was then dried at 105℃ for 17h, ground and calcined at 400℃ at a heating rate of 2℃ / min for 5h, after which a 6wt% nickel oxide nanocluster-loaded indium oxide catalyst was obtained, which was then pressed and sieved to 40-60 mesh.
[0020] The carbon dioxide hydrogenation reaction was carried out in a fixed bed reactor with an inner diameter of 10 mm. Before the reaction, the catalyst was gradually heated to 300°C in N2, activated for 1 hour, and then cooled to 40°C. After that, the gas channel was switched to a gas mixture of CO2, H2, and Ar. All N2 was purged out of the reaction system for a period of time, and then the fixed bed was pressurized to 4.0 MPa and kept flowing at a flow rate of 30 mL / min for 1 hour. The reaction conditions were as follows: temperature 300°C, pressure 4.0 MPa, volume space velocity 18000 h -1 , H2:CO2=3:1, the product composition was analyzed by gas chromatography, and the performance evaluation results are shown in Table 1.
[0021] Figure 1 is the XRD pattern of the nanocluster-supported indium oxide catalyst prepared in this embodiment. Figure 1 It can be seen that the main crystal phase of the prepared nanocluster-loaded indium oxide catalyst is cubic indium oxide, and no characteristic diffraction peak of nickel oxide is observed, indicating that the loaded nickel oxide is a nanocluster.
[0022] Figure 2 : is the STEM and EDX elemental distribution diagram of the nanocluster supported indium oxide catalyst prepared in this embodiment. Figure 2 It can be seen that the prepared catalyst is an indium oxide catalyst supported on the surface of nickel oxide nanoclusters.
[0023] Embodiment 2:
[0024] First, 0.321g of copper acetate monohydrate was dissolved in a mixture of 20mL of methanol, ethanol and deionized water in a round-bottom flask. Then 2g of indium oxide powder was added to the solution, followed by 30 minutes of ultrasonic treatment. The flask was then connected to a vacuum rotary evaporator and evaporated at room temperature at a rotation speed of 20rpm until all the solvent evaporated. The solid was then dried at 105℃ for 17h, ground and calcined at 300℃ at a heating rate of 2℃ / min for 5h, after which a 6wt% copper oxide nanocluster-loaded indium oxide catalyst was obtained, which was then pressed and sieved to 40-60 mesh.
[0025] The carbon dioxide hydrogenation reaction was carried out in a fixed bed reactor with an inner diameter of 10 mm. Before the reaction, the catalyst was gradually heated to 300°C in N2, activated for 1 hour, and then cooled to 40°C. After that, the gas channel was switched to a gas mixture of CO2, H2, and Ar. All N2 was purged out of the reaction system for a period of time, and then the fixed bed was pressurized to 4.0 MPa and kept flowing at a flow rate of 30 mL / min for 1 hour. The reaction conditions were as follows: temperature 300°C, pressure 4.0 MPa, volume space velocity 18000 h -1 , H2:CO2=3:1, the product composition was analyzed by gas chromatography, and the performance evaluation results are shown in Table 1.
[0026] Embodiment 3:
[0027] First, 0.442g of zirconium nitrate pentahydrate was dissolved in a mixture of 20mL of methanol, ethanol and deionized water in a round-bottom flask. Then 2g of indium oxide powder was added to the solution, followed by 30 minutes of ultrasonic treatment. The flask was then connected to a vacuum rotary evaporator and evaporated at room temperature at a rotation speed of 20rpm until all the solvent evaporated. The solid was then dried at 105℃ for 17h, ground and calcined at 300℃ at a heating rate of 2℃ / min for 5h, after which a 6wt% zirconium oxide nanocluster-loaded indium oxide catalyst was obtained, which was then pressed and sieved to 40-60 mesh.
[0028] The carbon dioxide hydrogenation reaction was carried out in a fixed bed reactor with an inner diameter of 10 mm. Before the reaction, the catalyst was gradually heated to 300°C in N2, activated for 1 hour, and then cooled to 40°C. After that, the gas channel was switched to a gas mixture of CO2, H2, and Ar. All N2 was purged out of the reaction system for a period of time, and then the fixed bed was pressurized to 4.0 MPa and kept flowing at a flow rate of 30 mL / min for 1 hour. The reaction conditions were as follows: temperature 300°C, pressure 4.0 MPa, volume space velocity 18000 h -1 , H2:CO2=3:1, the product composition was analyzed by gas chromatography, and the performance evaluation results are shown in Table 1.
[0029] Embodiment 4:
[0030] First, 0.233g of nickel nitrate hexahydrate was dissolved in a mixture of 20mL of methanol, ethanol and deionized water in a round-bottom flask. Then 2g of indium oxide powder was added to the solution, followed by 30 minutes of ultrasonic treatment. The flask was then connected to a vacuum rotary evaporator and evaporated at room temperature at a rotation speed of 20rpm until all the solvent evaporated. The solid was then dried at 105℃ for 17h, ground and calcined at 400℃ at a heating rate of 2℃ / min for 5h, after which 3wt% nickel oxide nanoclusters loaded with indium oxide catalyst were obtained, which was then pressed and sieved to 40-60 mesh.
[0031] The carbon dioxide hydrogenation reaction was carried out in a fixed bed reactor with an inner diameter of 10 mm. Before the reaction, the catalyst was gradually heated to 300°C in N2, activated for 1 hour, and then cooled to 40°C. After that, the gas channel was switched to a gas mixture of CO2, H2, and Ar. All N2 was purged out of the reaction system for a period of time, and then the fixed bed was pressurized to 4.0 MPa and kept flowing at a flow rate of 30 mL / min for 1 hour. The reaction conditions were as follows: temperature 300°C, pressure 4.0 MPa, volume space velocity 18000 h -1 , H2:CO2=3:1, the product composition was analyzed by gas chromatography, and the performance evaluation results are shown in Table 1.
[0032] Embodiment 5:
[0033] First, 0.078g of nickel nitrate hexahydrate was dissolved in a mixture of 20mL of methanol, ethanol and deionized water in a round-bottom flask. Then 2g of indium oxide powder was added to the solution, followed by 30 minutes of ultrasonic treatment. The flask was then connected to a vacuum rotary evaporator and evaporated at room temperature at a rotation speed of 20rpm until all the solvent evaporated. The solid was then dried at 105℃ for 17h, ground and calcined at 400℃ at a heating rate of 2℃ / min for 5h, after which 1wt% nickel oxide nanocluster-loaded indium oxide catalyst was obtained, which was then pressed and sieved to 40-60 mesh.
[0034] The carbon dioxide hydrogenation reaction was carried out in a fixed bed reactor with an inner diameter of 10 mm. Before the reaction, the catalyst was gradually heated to 300°C in N2, activated for 1 hour, and then cooled to 40°C. After that, the gas channel was switched to a gas mixture of CO2, H2, and Ar. All N2 was purged out of the reaction system for a period of time, and then the fixed bed was pressurized to 4.0 MPa and kept flowing at a flow rate of 30 mL / min for 1 hour. The reaction conditions were as follows: temperature 300°C, pressure 4.0 MPa, volume space velocity 18000 h -1 , H2:CO2=3:1, the product composition was analyzed by gas chromatography, and the performance evaluation results are shown in Table 1.
[0035] Blank control example:
[0036] First, 0.0g of nickel nitrate hexahydrate was dissolved in a mixture of 20mL of methanol, ethanol and deionized water in a round-bottom flask. Then 2g of indium oxide powder was added to the solution, followed by 30 minutes of ultrasonic treatment. The flask was then connected to a vacuum rotary evaporator and evaporated at room temperature at a rotation speed of 20rpm until all the solvent evaporated. The solid was then dried at 105℃ for 17h, ground and calcined at 400℃ at a heating rate of 2℃ / min for 5h, after which 0wt% nickel oxide nanocluster-loaded indium oxide catalyst was obtained, which was then pressed and sieved to 40-60 mesh.
[0037] The carbon dioxide hydrogenation reaction was carried out in a fixed bed reactor with an inner diameter of 10 mm. Before the reaction, the catalyst was gradually heated to 300°C in N2, activated for 1 hour, and then cooled to 40°C. After that, the gas channel was switched to a gas mixture of CO2, H2, and Ar. All N2 was purged out of the reaction system for a period of time, and then the fixed bed was pressurized to 4.0 MPa and kept flowing at a flow rate of 30 mL / min for 1 hour. The reaction conditions were as follows: temperature 300°C, pressure 4.0 MPa, volume space velocity 18000 h -1 , H2:CO2=3:1, the product composition was analyzed by gas chromatography, and the performance evaluation results are shown in Table 1.
[0038] Comparative Example 1:
[0039] First, 0.262g of nickel nitrate hexahydrate and 4.242g of indium nitrate were dissolved in 100mL of ethanol and 2-ethylhexanoic acid (volume ratio 1:1), and the total concentration of nickel-indium ions was 0.15mol / L. Then the mixture was passed into a flame jet combustion device with a flow rate of 5mL / min. The flame was provided by 1.5L / min of methane, 3.0L / min of oxygen and 5.0L / min of additional dispersed flowing oxygen. The powder left after combustion was the catalyst, which was then pressed and sieved to 40-60 mesh to obtain a 6wt% nickel oxide-doped indium oxide catalyst.
[0040] The carbon dioxide hydrogenation reaction was carried out in a fixed bed reactor with an inner diameter of 10 mm. Before the reaction, the catalyst was gradually heated to 300°C in N2, activated for 1 hour, and then cooled to 40°C. After that, the gas channel was switched to a gas mixture of CO2, H2, and Ar. All N2 was purged out of the reaction system for a period of time, and then the fixed bed was pressurized to 4.0 MPa and kept flowing at a flow rate of 30 mL / min for 1 hour. The reaction conditions were as follows: temperature 300°C, pressure 4.0 MPa, volume space velocity 18000 h -1 , H2:CO2=3:1, the product composition was analyzed by gas chromatography, and the performance evaluation results are shown in Table 1.
[0041] Table 1 Reaction results of catalysts obtained from Examples 1-5, blank control examples and comparative example 1
[0042]
[0043]
[0044] As can be seen from Table 1, when the nanocluster-loaded indium oxide catalyst provided by the present invention is used in the reaction of preparing methanol by hydrogenation of carbon dioxide, when the nanocluster is loaded, the carbon dioxide conversion rate and the methanol yield both show a significant increase trend, and the higher the loading amount, the better the catalytic performance. In Example 1, when the loading amount is 6.0wt% nickel oxide, the carbon dioxide conversion rate reaches 15.3% (300°C) and the methanol yield reaches 25.4mmol / g cat / h, which is 7 times and 12 times higher than that of the indium oxide catalyst (blank control example), and 5 times higher than that of the catalyst in comparative example 1. The loaded copper oxide and zirconium oxide both improved the methanol performance to varying degrees.
[0045] The applicant declares that the present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.
Claims
1. A method for preparing a metal oxide nanocluster-supported indium oxide catalyst, characterized in that: The size of the metal oxide nanoclusters in the catalyst is 0.5 nm to 2 nm, and the metal oxide nanoclusters are loaded on the surface of indium oxide. The method comprises the following steps: 1) dissolving a soluble metal salt in a solvent to obtain a metal salt solution, wherein the solvent is a mixture of methanol, ethanol and deionized water, adding indium oxide powder to the metal salt solution, ultrasonicating for 5-60 minutes to prepare a catalyst precursor solution, and then vacuum rotary evaporating at room temperature of 5° C. to 30° C. until the solvent is completely volatilized; 2) After the solvent in step 1) evaporates, the remaining solid is dried and calcined in sequence to obtain the nanocluster-loaded indium oxide catalyst, wherein the drying temperature is 90°C to 120°C and the drying time is 10h to 24h; the calcination temperature is 250°C to 400°C and the calcination time is 2h to 8h.
2. The method according to claim 1, characterized in that In step 1), the soluble metal salt is selected from one of nickel nitrate, copper acetate and zirconium nitrate.
3. The method according to claim 1, characterized in that In step 1), the amount of the metal salt added is calculated based on the corresponding metal of the obtained catalyst, and the loading amount is not more than 20 wt%.
4. The method according to claim 1, characterized in that: In step 1), the amount of the metal salt added is calculated based on the corresponding metal of the obtained catalyst, and the loading amount is 3wt%-20wt%.
5. Use of the metal oxide nanoclusters supported indium oxide catalyst obtained by the method according to claim 1, characterized in that: Used for the fixed bed carbon dioxide hydrogenation to produce methanol reaction.
6. The use according to claim 5, characterized in that: The reaction conditions are: reaction temperature between 180℃ and 340℃, H2 / CO2 molar ratio between 1 and 6, reaction pressure between 1.0MPa and 5.0MPa, and volume space velocity between 4500h -1 ~28000h -1 between.
7. The use according to claim 5, characterized in that: The metal oxide nanocluster-loaded indium oxide catalyst is activated before being used in a fixed bed for the reaction of hydrogenating carbon dioxide to prepare methanol. The activation conditions are: in an inert gas atmosphere, the temperature is gradually increased to 150° C. to 350° C., and the activation time is between 1 h and 4 h, wherein the inert gas includes one or more of N2, Ar and He.