Preparation method and application of copper-magnesium-aluminum-zinc composite metal oxide
By preparing copper-magnesium aluminum-zinc composite metal oxide catalyst, the problems of easy loss of precious metals and environmental pollution in the prior art are solved, and a low-cost and efficient catalyst is provided for the α-alkylation reaction of alcohol ketones.
Patent Information
- Application Number
- CN202410411247.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-08
- Publication Date
- 2025-07-25
AI Technical Summary
In the prior art, the synthesis method of α-alkyl ketone uses halogenated hydrocarbons as alkylation reagents, which has environmental pollution problems, and the heterogeneous catalyst uses precious metals and is prone to loss, and alkali additives are required to be added, which lacks efficient and environmentally friendly catalysts.
A copper-magnesium-aluminum-zinc composite metal oxide catalyst is prepared, and the nitrate of copper, magnesium, aluminum and zinc is dissolved and reacted with an alkaline solution to form a hydrotalcite-like precursor and calcined to obtain a non-noble metal oxide catalyst for the α-alkylation reaction of alcohol ketones.
It achieves a low-cost, high-efficiency catalytic effect without alkali additives, and is suitable for the α-alkylation reaction of aromatic and fatty alcohol ketones, overcomes the problem of precious metal loss and improves the universality of the catalyst.
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Figure CN120361902A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of catalysts, and particularly relates to a preparation method and application of a copper-magnesium-aluminum-zinc composite metal oxide. Background Art
[0002] α-alkyl ketones are a very important class of compounds, showing a wide range of physiological and pharmacological activities, and are commonly used in the production and synthesis of drugs, fragrances, pesticides, etc. They have a large demand, high added value, good market prospects and economic benefits. Therefore, it has important practical significance for the preparation and synthesis of such organic compounds. The traditional method for synthesizing α-alkyl ketones is to use a halogenated hydrocarbon as an alkylating agent to react with a ketone under strong alkaline conditions to produce the corresponding product. However, this method uses highly toxic halogenated hydrocarbons and generates a large amount of waste salts harmful to the environment. Therefore, it is necessary to develop a more environmentally friendly approach to realize the synthesis of α-alkyl ketones, and the method of using an alcohol as an environmentally friendly alkylating agent to carry out an alkylation reaction with a ketone to prepare α-alkyl ketones has received extensive attention and research. The key to the better development of the α-alkylation reaction of an alcohol and a ketone lies in the research of catalysts. Since homogeneous catalysts have problems such as the need to add complex ligands, difficulty in separation, non-reusability, and high cost, it is very necessary to study more efficient heterogeneous catalysts. Some current heterogeneous catalysts have disadvantages such as the use of precious metals, easy loss of metals, and the use of alkali promoters. Therefore, it has important practical significance to develop more efficient and environmentally friendly catalysts. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide a preparation method and application of a copper-magnesium-aluminum-zinc composite metal oxide in view of the above-mentioned deficiencies of the prior art. The copper-magnesium-aluminum-zinc composite metal oxide prepared by this method is used as a catalyst, which is a non-precious metal oxide, has a low cost, overcomes the disadvantage of easy loss of metals in supported metal catalysts, does not require the addition of alkali promoters, has good universality, and is suitable for the α-alkylation reaction of aromatic and aliphatic alcohol-ketones.
[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a preparation method of a copper-magnesium-aluminum-zinc composite metal oxide, and the method is as follows:
[0005] S1. After mixing Cu(NO3)2·3H2O, Mg(NO3)2·6H2O, Al(NO3)3·9H2O and Zn(NO3)2·6H2O, dissolve them in deionized water to obtain solution A;
[0006] S2. After mixing NaOH and Na2CO3, dissolve them in deionized water to obtain solution B;
[0007] S3. Add the solution B obtained in S2 dropwise to the solution A obtained in S1. After the addition is completed, the pH value of the system is 10 - 12. Stir magnetically for 6 h, then age for 12 h. Filter the precipitate by suction and wash it until neutral, and then dry it at a temperature of 80 °C to obtain a hydrotalcite-like precursor.
[0008] S4. Calcinate the hydrotalcite-like precursor obtained in S3, and cool it naturally to room temperature. After grinding, a copper-magnesium-aluminum-zinc composite metal oxide is obtained. The calcination conditions are as follows: heat from room temperature to 450 °C - 600 °C at a heating rate of 5 °C / min, and keep the temperature constant for 2 h.
[0009] Preferably, the molar ratio of Cu(NO3)2·3H2O, Mg(NO3)2·6H2O, Al(NO3)3·9H2O, and Zn(NO3)2·6H2O in S1 is (0.3 - 0.5):2:1:1.
[0010] Preferably, the dosage ratio of NaOH, Na2CO3, and deionized water in S2 is 0.09 mol:0.0225 mol:30 mL.
[0011] Preferably, the dropping rate in S3 is 3 mL / min - 5 mL / min.
[0012] The present invention also provides an application of the copper-magnesium-aluminum-zinc composite metal oxide prepared by the above preparation method, and the copper-magnesium-aluminum-zinc composite metal oxide is used for catalyzing the α-alkylation reaction of alcohol ketones.
[0013] Preferably, the alcohol ketone is an aromatic or aliphatic alcohol ketone.
[0014] The present invention has the following advantages compared with the prior art:
[0015] The copper-magnesium-aluminum-zinc composite metal oxide prepared by the present invention is used as a catalyst, which is a non-precious metal oxide. Compared with the precious metal system, it has a low cost and overcomes the disadvantage that the metal in the supported metal catalyst is easy to lose. Some existing catalyst systems need to add an alkali promoter to catalyze the reaction, while this catalyst does not need to add an alkali promoter. This catalyst system has good universality and is suitable for the α-alkylation reaction of aromatic and aliphatic alcohol ketones.
[0016] The present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings
[0017] Figure 1 It is the SEM diagram of CuMgAlZn-Ⅰ-550 and CuMgAlZn-Ⅱ-550 prepared in Examples 1 - 2 of the present invention.
[0018] Figure 2It is the reaction formula of acetophenone and benzyl alcohol in Embodiment 3 of the present invention.
[0019] Figure 3 It is the XRD pattern of each copper-magnesium-aluminum-zinc composite metal oxide in Embodiment 3 of the present invention.
[0020] Figure 4 It is the reaction formula of the α-alkylation reaction of fatty alcohol ketone in Embodiment 3 of the present invention. Detailed implementation manners
[0021] Embodiment 1
[0022] The preparation method of the copper-magnesium-aluminum-zinc composite metal oxide in this embodiment is as follows:
[0023] S1. After mixing Cu(NO3)2·3H2O (1.2103 g, 0.005 mol), Mg(NO3)2·6H2O (5.1282 g, 0.02 mol), Al(NO3)3·9H2O (3.7513 g, 0.01 mol) and Zn(NO3)2·6H2O (2.9749 g, 0.01 mol) with a molar ratio of 0.5:2:1:1, dissolve them in 100 mL of deionized water to obtain solution A;
[0024] S2. Dissolve 3.6 g (0.09 mol) of NaOH and 2.3848 g (0.0225 mol) of Na2CO3 in 30 mL of deionized water to obtain solution B;
[0025] S3. At a dropping rate of 3 mL / min, drop the solution B obtained in S2 into the solution A obtained in S1. After the dropping is completed, the pH value of the system is 10. Stir magnetically for 6 h, then age for 12 h. Filter the precipitate and wash it until neutral, and dry it at a temperature of 80 °C to obtain a hydrotalcite-like precursor, named CuMgAlZn-Ⅰ;
[0026] S4. Calcinate the hydrotalcite-like precursor obtained in S3, cool it naturally to room temperature, and grind it to obtain a copper-magnesium-aluminum-zinc composite metal oxide, named CuMgAlZn-Ⅰ-550; the calcination conditions are: heat up from room temperature to 550 °C at a heating rate of 5 °C / min, and keep it at a constant temperature for 2 h.
[0027] In addition, the catalyst copper-magnesium-aluminum-zinc composite metal oxide is prepared according to the method of this embodiment, with the difference that: heat up to 600 °C in the calcination conditions, and the obtained sample is denoted as CuMgAlZn-Ⅰ-600.
[0028] Embodiment 2
[0029] The preparation method of the copper-magnesium-aluminum-zinc composite metal oxide in this embodiment is as follows:
[0030] S1. Mix 0.3:2:1:1 molar ratio of Cu(NO3)2·3H2O (0.7262 g, 0.003 mol), Mg(NO3)2·6H2O (5.1282 g, 0.02 mol), Al(NO3)3·9H2O (3.7513 g, 0.01 mol) and Zn(NO3)2·6H2O (2.9749 g, 0.01 mol), and dissolve them in 100 mL of deionized water to obtain solution A;
[0031] S2. Mix 3.6 g (0.09 mol) of NaOH and 2.3848 g (0.0225 mol) of Na2CO3, and dissolve them in 30 mL of deionized water to obtain solution B;
[0032] S3. Dropwise add solution B obtained in S2 into solution A obtained in S1 at a dropping rate of 5 mL / min. After the dropping is completed, the pH value of the system is 12. Magnetically stir for 6 h, then age for 12 h. Filter and wash the precipitate until it is neutral, and dry it at 80 °C to obtain a hydrotalcite-like precursor, named CuMgAlZn-Ⅱ;
[0033] S4. Calcinate the hydrotalcite-like precursor obtained in S3, cool it naturally to room temperature, and grind it to obtain a copper-magnesium-aluminum-zinc composite metal oxide, named CuMgAlZn-Ⅱ-600; The calcination conditions are: heat from room temperature to 600 °C at a heating rate of 5 °C / min, and keep it at a constant temperature for 2 h.
[0034] In addition, prepare the copper-magnesium-aluminum-zinc composite metal oxide catalyst according to the method of this example, with the difference being that in the calcination conditions, heat up to 550 °C, and the obtained sample is denoted as CuMgAlZn-Ⅱ-550.
[0035] As Figure 1 , Figure 1 a and 1b are SEM images of CuMgAlZn-Ⅰ-550 prepared in Example 1 and CuMgAlZn-Ⅱ-550 prepared in Example 2, respectively. It can be seen from the figure that the catalyst presents a granular shape, and the particles have a lamellar structure, which is consistent with the hydrotalcite-like structure of the precursor.
[0036] Comparative Example 1
[0037] The preparation method of the copper-magnesium-aluminum-zinc composite metal oxide in this comparative example is the same as that in Example 2, except that in step S4, the calcination conditions are heated to 450 °C and 500 °C, and the obtained samples are denoted as CuMgAlZn-Ⅱ-450 and CuMgAlZn-Ⅱ-500, respectively.
[0038] Comparative Example 2
[0039] The preparation method of the copper-magnesium-aluminum-zinc composite metal oxide of this comparative example is as follows:
[0040] S1. After mixing Cu(NO3)2·3H2O (0.2421 g, 0.001 mol), Mg(NO3)2·6H2O (5.1282 g, 0.02 mol), Al(NO3)3·9H2O (3.7513 g, 0.01 mol) and Zn(NO3)2·6H2O (2.9749 g, 0.01 mol) in a molar ratio of 0.1:2:1:1, dissolve them in 100 mL of deionized water to obtain solution A;
[0041] S2. After mixing 3.6 g (0.09 mol) of NaOH and 2.3848 g (0.0225 mol) of Na2CO3, dissolve them in 30 mL of deionized water to obtain solution B;
[0042] S3. At a dropping rate of 5 mL / min, drop the solution B obtained in S2 into the solution A obtained in S1. After the dropping is completed, the pH value of the system is 10. Stir magnetically for 6 h and then age for 12 h. Filter and wash the precipitate until it is neutral, and dry it at a temperature of 80 °C to obtain a hydrotalcite-like precursor, named CuMgAlZn--Ⅲ;
[0043] S4. Calcinate the hydrotalcite-like precursor obtained in S3, cool it naturally to room temperature, and grind it to obtain a copper-magnesium-aluminum-zinc composite metal oxide, named CuMgAlZn-Ⅲ-550; the calcination conditions are: heat from room temperature to 550 °C at a heating rate of 5 °C / min and keep it at a constant temperature for 2 h.
[0044] In addition, the catalyst copper-magnesium-aluminum-zinc composite metal oxide was prepared according to the method of this example, with the difference that the temperature was raised to 600 °C in the calcination conditions, and the obtained sample was denoted as CuMgAlZn-Ⅲ-600.
[0045] Example 3
[0046] This example is about the application of the copper-magnesium-aluminum-zinc composite metal oxides prepared in Examples 1-2 and Comparative Examples 1-2 as catalysts for the α-alkylation reaction of alcohol ketones.
[0047] Weigh the catalyst (30 mg), ketone (0.5 mmol), alcohol (0.6 mmol), and toluene (2 - 3 mL) into a dry reaction tube, fill the tube with argon to ensure that the reaction proceeds under an inert atmosphere. After the filling is completed, place it on the reactor for reaction, heat it to 150 °C for 20 hours, and then cool it to room temperature. After the reaction is completed, analyze the results using gas chromatography.
[0048] Using the reaction of acetophenone and benzyl alcohol as a model reaction, the performance of the above-prepared catalysts was tested. The reaction equation is as Figure 2 shown. The main product of the reaction is a (dihydrochalcone), and b (chalcone) is a by-product.
[0049] The reaction was carried out at 150 °C for 20 hours with 30 mg of the catalyst, 3 mL of toluene, and under Ar. All conversion and selectivity data were from uncorrected gas chromatography data (the data in Table 1).
[0050] Table 1 Catalytic performance test results of each catalyst prepared in Examples 1-2 and Comparative Examples 1-2
[0051]
[0052] As can be seen from Table 1, the catalysts CuMgAlZn-I-600, CuMgAlZn-I-550, CuMgAlZn-II-600, and CuMgAlZn-II-550 showed excellent performance in the α-alkylation reaction of acetophenone and benzyl alcohol, with the conversion rate between 79% and 98%, and the selectivity of the target product between 91% and 98%. While the catalysts CuMgAlZn-II-500, CuMgAlZn-II-450, CuMgAlZn-III-600, and CuMgAlZn-III-550 had relatively poor effects, with the conversion rate between 37% and 81%, and the selectivity of the target product between 4% and 68%. The results shown in Table 1 indicate that the activity of the catalyst is affected by both the calcination temperature and the catalyst composition.
[0053] The reaction of acetophenone and benzyl alcohol was catalyzed by CuMgAlZn-I-550, and the isolated yield of product a (dihydrochalcone) was 91%.
[0054] Figure 3 are the XRD patterns of each catalyst involved in Table 1. As can be seen from the figure, the diffraction peaks of all catalysts are relatively broad, which is due to the small particle size or low crystallinity of the catalyst, especially for the catalysts with relatively poor effects. The positions of the diffraction peaks of the catalysts with better catalytic effects are basically the same, indicating that their crystal types are basically the same. Some of the corresponding diffraction peaks of the catalysts with relatively poor catalytic effects have lower intensities, and their crystal forms are slightly different from those of the catalysts with better catalytic effects. Due to the broad diffraction peaks, each diffraction peak may contain the crystal forms of different substances. The substances contained in the more obvious diffraction peaks are as Figure 3 shown.
[0055] The copper-magnesium-aluminum-zinc composite metal oxide prepared by the present invention is used as a catalyst. It is a non-precious metal oxide. Compared with the precious metal system, it has low cost and overcomes the disadvantage that the metal of the supported metal catalyst is easy to lose. Some existing catalyst systems require additional addition of alkali additives to catalyze the reaction. The catalyst does not need to add alkali additives. The catalyst system has good universality and is suitable for α-alkylation reactions of aromatic and fatty alcohols and ketones.
[0056] The copper-magnesium-aluminum-zinc composite metal oxide prepared by the present invention is used as a catalyst to catalyze the α-alkylation reaction of fatty alcohols and ketones. Figure 4 .
[0057] The α-alkylation reaction of p-methoxyacetophenone and n-butanol was catalyzed by the catalyst CuMgAlZn-I-550, and the main product was 1-(4-methoxyphenyl)hexane-1-one with an isolated yield of 62%.
[0058] The α-alkylation reaction of p-methoxyacetophenone and isoamyl alcohol was catalyzed by the catalyst CuMgAlZn-I-550, and the main product was 1-(4-methoxyphenyl)-5-methyl-hexane-1-one, and the isolation yield was 89%.
[0059] The present invention constructs a non-precious metal composite oxide multiphase catalytic system, and by regulating the Cu content in the composite oxide and the reaction conditions, a highly efficient, inexpensive, metal-unfavorable multiphase catalytic system without the participation of alkali co-catalysts is established.
[0060] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.
Claims
1. A preparation method of a copper-magnesium-aluminum-zinc composite metal oxide, characterized in that, The method is as follows: S1. After mixing Cu(NO3)2·3H2O, Mg(NO3)2·6H2O, Al(NO3)3·9H2O and Zn(NO3)2·6H2O, dissolve them in deionized water to obtain solution A; S2. After mixing NaOH and Na2CO3, dissolve them in deionized water to obtain solution B; S3. Drop the solution B obtained in S2 into the solution A obtained in S1. After the dropping is completed, the pH value of the system is 10 - 12. Stir magnetically for 6 h, then age for 12 h. Filter and wash the precipitate until it is neutral, and dry it at a temperature of 80 °C to obtain a hydrotalcite-like precursor; S4. Calcine the hydrotalcite-like precursor obtained in S3, cool it naturally to room temperature, and grind it to obtain a copper-magnesium-aluminum-zinc composite metal oxide; the calcination conditions are: heat from room temperature to 550 °C - 600 °C at a heating rate of 5 °C / min, and keep the temperature constant for 2 h.
2. The preparation method of a copper-magnesium-aluminum-zinc composite metal oxide according to claim 1, characterized in that, The molar ratio of Cu(NO3)2·3H2O, Mg(NO3)2·6H2O, Al(NO3)3·9H2O and Zn(NO3)2·6H2O described in S1 is (0.3 - 0.5):2:1:
1.
3. The preparation method of a copper-magnesium-aluminum-zinc composite metal oxide according to claim 1, characterized in that, The dosage ratio of NaOH, Na2CO3 and deionized water described in S2 is 0.09 mol:0.0225 mol:30 mL.
4. A method for preparing a copper-magnesium-aluminum-zinc composite metal oxide according to claim 1, characterized in that, The dropping rate in S3 is 3 mL / min - 5 mL / min.
5. Use of the copper-magnesium-aluminum-zinc composite metal oxide prepared by the preparation method according to any one of claims 1-4, characterized in that, The copper-magnesium-aluminum-zinc composite metal oxide is used to catalyze the α-alkylation reaction of alcohol ketones.
6. The application according to claim 5, characterized in that, The alcohol ketones are aromatic or aliphatic alcohol ketones.