High-efficiency aldehyde liquid-phase hydrogenation catalyst, preparation method and application thereof
By preparing Cu-Pd bimetallic alloy catalysts and combining them with Ca-modified β molecular sieve supports, the problem of high cost of Pd catalysts was solved, and efficient and environmentally friendly liquid-phase hydrogenation of aldehydes was achieved, exhibiting high activity and selectivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-12-27
- Publication Date
- 2026-06-30
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalyst technology, specifically relating to a highly efficient aldehyde liquid-phase hydrogenation catalyst suitable for the liquid-phase hydrogenation of aldehyde compounds and its preparation method. Background Technology
[0002] Aldehydes, as important intermediates in organic synthesis, have wide applications in industrial production. Their hydrogenation reduction to the corresponding alcohols is a key step in the synthesis of many chemicals. Butanol and octanol are widely used alcohols, including plasticizers, solvents, dehydrating agents, dispersants, petroleum additives, and synthetic fragrances. There are two processes for hydrogenating aldehydes to butanol and octanol: gas-phase and liquid-phase methods. The gas-phase method is characterized by mild reaction conditions and simple industrial equipment, but it requires pre-vaporization of raw materials, produces more byproducts, and has higher energy consumption. Liquid-phase hydrogenation has lower energy consumption, higher production capacity, and higher product quality, but it requires higher reaction pressure and has higher equipment costs. Most foreign companies use liquid-phase hydrogenation, while most existing domestic plants use gas-phase hydrogenation, but the proportion of liquid-phase hydrogenation plants is gradually increasing.
[0003] Currently, research on the liquid-phase hydrogenation of butyraldehyde and octenal mainly focuses on nickel-based catalysts. Patent CN103506123B discloses an aldehyde hydrogenation catalyst with a nickel mass fraction of 15%-30% prepared by co-precipitation, which can be used for the liquid-phase hydrogenation of propionaldehyde, butyraldehyde, or octenal. Niu et al. (Journal of Chemical Engineering of Chinese Universities, 2017, 31(06):1333-1339) studied the effect of acidity and alkalinity on the performance of supported Ni-based catalysts in the liquid-phase hydrogenation of octenal.
[0004] Copper-chromium catalysts are widely used in the liquid-phase hydrogenation reaction of furfural. Patents CN106582671A, CN105498788B, CN107952444 A, and CN107970942B disclose copper-chromium catalysts with different compositions and preparation methods, exhibiting high catalytic activity and selectivity for furfural-to-furfuryl alcohol production. However, the toxicity of metallic chromium limits its large-scale industrial application. In recent years, with the rapid development of catalysis and materials science, developing efficient and environmentally friendly liquid-phase aldehyde hydrogenation catalysts that can operate stably under liquid-phase feed conditions has practical application value. Patent CN201711022167.8 describes a method for preparing a PdCu alloy precipitate by contacting an active palladium precursor and an active copper precursor in a molten substrate, followed by cooling and precipitation. The washed PdCu alloy precipitate is then mixed with an organic solvent to obtain a solid-liquid mixture, which is then contacted with an inorganic oxide support to obtain a catalyst for the liquid-phase hydrogenation reaction of furfural. The catalyst has a high active Pd loading, and the preferred Pd to Cu molar ratio is 1:1-1:3. Since Pd is expensive, it is of great application value to fully utilize the activity of the Cu component and improve the intrinsic activity of Cu active sites through electronic and structural property regulation to achieve the preparation of a highly efficient, environmentally friendly, and inexpensive copper-based liquid-phase hydrogenation catalyst. Summary of the Invention
[0005] The technical problem to be solved by the present invention is the high cost of existing catalysts with Pd as the active component.
[0006] To address the aforementioned problems, the basic technical concept of this invention is to fully utilize the activity of the Cu component and improve the intrinsic activity of the Cu active sites through electronic and structural performance regulation, thereby preparing a highly efficient, environmentally friendly, and inexpensive copper-based liquid-phase hydrogenation catalyst.
[0007] Based on the above technical concept, this invention first provides a highly efficient liquid-phase hydrogenation catalyst for aldehydes, wherein the catalyst is composed of an active metal component and a support. The active metal component is a bimetallic alloy of Cu and Pd, and the support is a β-molecular sieve modified with Ca as an auxiliary agent.
[0008] Furthermore, based on the mass of the catalyst, the catalyst contains 10-20 wt% Cu, 0.5-2 wt% Pd, and the remainder is Ca-β molecular sieve.
[0009] Furthermore, based on metal elements, the mass ratio of Cu to Pd is 5-20:1, preferably 8-15:1. Secondly, this invention provides a method for preparing the above-mentioned high-efficiency aldehyde liquid-phase hydrogenation catalyst, the method comprising the following steps:
[0010] (1) H-β molecular sieve was added to calcium nitrate solution for exchange three times, and then dried and calcined to obtain Ca-modified Ca-β molecular sieve;
[0011] (2) Dissolve Cu salt and Pd salt in deionized water to prepare a solution, add Ca-modified β molecular sieve for impregnation, and then pretreat by drying, calcination, and high-temperature reduction to obtain the catalyst. Further, the Cu salt and Pd salt are selected from one or both of the corresponding metal nitrates or acetates, preferably nitrates. Further, the exchange process in step (1) specifically includes the following conditions:
[0012] The calcium nitrate solution concentration was 1 mol / L, the mass ratio of solution to molecular sieve was 10:1, the exchange was carried out at 80℃, and the cumulative exchange time was 3 hours. The calcination temperature was 550℃, and the calcination time was 4-6 hours.
[0013] Furthermore, the impregnation process described in step (2) specifically includes the following conditions:
[0014] The Ca-β molecular sieve was placed in a mixed metal salt solution prepared by dissolving Cu salt and Pd salt in deionized water using the equal volume impregnation method. The solution was left to stand at room temperature for 24 hours. The volume of the aforementioned metal salt solution was equal to the pore volume of the Ca-β molecular sieve.
[0015] Furthermore, the drying temperature in steps (1) and (2) is 100-120℃ and the drying time is 12-24h.
[0016] The calcination temperature in step (2) is 320-380℃ and the calcination time is 2-4h; the high-temperature reduction pretreatment process is to reduce for 5-12h at 230℃ in a 20% H2-N2 atmosphere.
[0017] Furthermore, this invention provides the application of the above-described catalyst in the liquid-phase hydrogenation of butyraldehyde or octenal. The beneficial effects of this application include, but are not limited to:
[0018] (1) This invention provides an aldehyde liquid-phase hydrogenation catalyst. The obtained catalyst exhibits high activity, high selectivity and good stability. It is particularly suitable for the liquid-phase hydrogenation reaction of aldehyde compounds and has a wide range of industrial applications.
[0019] (2) This invention provides a highly efficient liquid-phase hydrogenation catalyst for aldehydes. The active metal component is a bimetallic system of Cu and Pd. There is electron transfer between Cu and Pd, which can change the electron cloud density of Cu and thus optimize the adsorption strength of the reactants. The synergistic effect of the two can significantly improve the hydrogenation activity of the catalyst.
[0020] (3) The present invention provides an aldehyde liquid-phase hydrogenation catalyst. The addition of molecular sieve Ca-β can promote the active component to be anchored on the support and exist stably through the interaction between the support and the metal species. At the same time, the molecular sieve has the properties of aluminum, silicon and calcium ions, which can effectively adjust the ratio of acid and basic sites of the catalyst, so that the catalyst exhibits high alcohol selectivity. Detailed Implementation
[0021] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0022] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0023] Example 1 (18% Cu - 1% Pd - 75% support)
[0024] Weigh 23.6 g of calcium nitrate and dissolve it in 100 mL of deionized water to obtain solution I. Weigh 10 g of H-β molecular sieve and place it in solution I, then treat it in an 80 °C water bath with stirring for 3 h. Repeat the above process twice, and then calcine the resulting sample at 550 °C for 4 h to obtain Ca-β molecular sieve.
[0025] 10.6254 g of copper nitrate and 0.4330 g of palladium nitrate were weighed and dissolved in 106 mL of water. 44.2725 g of Ca-β molecular sieve was weighed and placed in the mixed metal salt solution. The mixture was allowed to stand at room temperature for 24 h, dried at 100 °C for 12 h, and then calcined at 330 °C for 4 h and reduced in a 20% H2-N2 atmosphere for 6 h to obtain the catalyst.
[0026] Example 2 (18% Cu - 2% Pd - 75% support)
[0027] Weigh 23.6 g of calcium nitrate and dissolve it in 100 mL of deionized water to obtain solution I. Weigh 10 g of H-β molecular sieve and place it in solution I, then treat it in an 80 °C water bath with stirring for 3 h. Repeat the above process twice, and then calcine the resulting sample at 550 °C for 4 h to obtain Ca-β molecular sieve.
[0028] 10.6254 g of copper nitrate and 0.8660 g of palladium nitrate were weighed and dissolved in 106 mL of water. 44.2725 g of Ca-β molecular sieve was weighed and placed in the mixed metal salt solution. The mixture was allowed to stand at room temperature for 24 h, dried at 100 °C for 12 h, and then calcined at 330 °C for 4 h and reduced in a 20% H2-N2 atmosphere for 10 h to obtain the catalyst.
[0029] Example 3 (15% Cu - 1.5% Pd - 75% support)
[0030] Weigh 23.6 g of calcium nitrate and dissolve it in 100 mL of deionized water to obtain solution I. Weigh 10 g of H-β molecular sieve and place it in solution I, then treat it in an 80 °C water bath with stirring for 3 h. Repeat the above process twice, and then calcine the resulting sample at 550 °C for 4 h to obtain Ca-β molecular sieve.
[0031] 8.8545 g of copper nitrate and 0.6495 g of palladium nitrate were weighed and dissolved in 89 mL of water. 44.2725 g of Ca-β molecular sieve was weighed and placed in the mixed metal salt solution. The mixture was allowed to stand at room temperature for 24 h, dried at 100 °C for 12 h, and then calcined at 330 °C for 4 h and reduced in a 20% H2-N2 atmosphere for 6 h to obtain the catalyst.
[0032] Example 4 (18% Cu - 0.5% Pd - 75% support)
[0033] Weigh 23.6 g of calcium nitrate and dissolve it in 100 mL of deionized water to obtain solution I. Weigh 10 g of H-β molecular sieve and place it in solution I, then treat it in an 80 °C water bath with stirring for 3 h. Repeat the above process twice, and then calcine the resulting sample at 550 °C for 4 h to obtain Ca-β molecular sieve.
[0034] 10.6254 g of copper nitrate and 0.2165 g of palladium nitrate were weighed and dissolved in 106 mL of water. 44.2725 g of Ca-β molecular sieve was weighed and placed in the mixed metal salt solution. The mixture was allowed to stand at room temperature for 24 h, dried at 100 °C for 12 h, and then calcined at 330 °C for 4 h and reduced in a 20% H2-N2 atmosphere for 6 h to obtain the catalyst.
[0035] Comparative Example 1 (18% Cu-support)
[0036] Weigh 23.6 g of calcium nitrate and dissolve it in 100 mL of deionized water to obtain solution I. Weigh 10 g of H-β molecular sieve and place it in solution I, then treat it in an 80 °C water bath with stirring for 3 h. Repeat the above process twice, and then calcine the resulting sample at 550 °C for 4 h to obtain Ca-β molecular sieve.
[0037] 10.6254 g of copper nitrate was dissolved in 106 mL of water. 44.2725 g of Ca-β molecular sieve was placed in a mixed metal salt solution and allowed to stand at room temperature for 24 h. The solution was then dried at 100 °C for 12 h. The sample was then calcined at 330 °C for 4 h and reduced in a 20% H2-N2 atmosphere for 6 h to obtain the catalyst.
[0038] Comparative Example 2 (2% Pd-carrier)
[0039] Weigh 23.6 g of calcium nitrate and dissolve it in 100 mL of deionized water to obtain solution I. Weigh 10 g of H-β molecular sieve and place it in solution I, then treat it in an 80 °C water bath with stirring for 3 h. Repeat the above process twice, and then calcine the resulting sample at 550 °C for 4 h to obtain Ca-β molecular sieve.
[0040] 0.8660 g of palladium nitrate was dissolved in 86 mL of water. 43.3020 g of Ca-β molecular sieve was placed in a mixed metal salt solution and allowed to stand at room temperature for 24 h. The sample was then dried at 100 °C for 12 h. The sample was then calcined at 330 °C for 4 h and reduced in a 20% H2-N2 atmosphere for 6 h to obtain the catalyst.
[0041] Example 5
[0042] In a fixed-bed reactor used in the laboratory, 5 mL of samples prepared in Examples 1-4 and Comparative Examples 1-2 were taken for butyraldehyde liquid-phase hydrogenation activity evaluation. The evaluation conditions were: reaction pressure 2.0 MPa, feed liquid hourly space velocity 2.0 h⁻¹. -1 The ratio of hydrogen to aldehyde was 15, and the ratio of butyraldehyde to butanol was 1:9. The evaluation results are shown in Table 1.
[0043] catalyst Butyraldehyde conversion rate / % Butanol selectivity / % Example 1 67.63 95.36 Example 2 69.52 96.42 Example 3 58.31 96.14 Example 4 67.37 93.27. Comparative Example 1 66.42 87.23 Comparative Example 2 3.68 53.11
[0044] Example 6
[0045] In a fixed-bed reactor used in the laboratory, 5 mL of the sample prepared in Example 2 was taken for butyraldehyde liquid-phase hydrogenation stability evaluation, under the same evaluation conditions as in Example 5. The evaluation results are shown in Table 2.
[0046]
[0047] Example 7
[0048] In a fixed-bed reactor used in the laboratory, 5 mL of samples prepared in Examples 1-4 and Comparative Examples 1-2 were taken for evaluation of the octenal liquid-phase hydrogenation activity. The evaluation conditions were: reaction pressure 2.4 MPa, feed liquid hourly space velocity 2.0 h⁻¹. -1 The ratio of hydrogen to aldehyde was 25, and the ratio of octenal to isooctyl alcohol was 1:9. The evaluation results are shown in Table 3.
[0049]
[0050]
[0051] Example 8
[0052] In a fixed-bed reactor used in the laboratory, 5 mL of the sample prepared in Example 2 was taken for evaluation of the stability of octenal liquid-phase hydrogenation. The evaluation conditions were the same as in Example 7. The evaluation results are shown in Table 4.
[0053]
[0054] The results above show that the high-efficiency aldehyde liquid-phase hydrogenation catalyst provided by the present invention can achieve high aldehyde conversion, high alcohol selectivity and high stability in the aldehyde liquid-phase hydrogenation reaction.
[0055] The above descriptions are merely a few embodiments of this application and do not constitute any limitation on this application. Any modifications or alterations made by those skilled in the art without departing from the scope of the technical solution disclosed above are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A highly efficient aldehyde liquid phase hydrogenation catalyst characterized in that The catalyst is composed of an active metal component and a support, wherein the active metal component is a bimetallic alloy of Cu and Pd, and the support is a β-molecular sieve modified with Ca as an additive.
2. The high efficiency aldehyde liquid phase hydrogenation catalyst of claim 1, wherein, The catalyst contains 10-20 wt% Cu, 0.5-5 wt% Pd, and the remainder is Ca-β molecular sieve, based on the mass of the catalyst.
3. The high efficiency aldehyde liquid phase hydrogenation catalyst of claim 1, wherein The mass ratio of Cu to Pd is 5-20:1, preferably 8-15:1, based on metallic elements.
4. The process for the preparation of a highly active liquid aldehyde hydrogenation catalyst according to claim 1 or 2 or 3, characterized in that, The method includes the following steps: (1) H-β molecular sieve was added to calcium nitrate solution for exchange three times, and then dried and calcined to obtain Ca-modified Ca-β molecular sieve; (2) Dissolve Cu salt and Pd salt in deionized water to prepare a solution, add Caβ molecular sieve for impregnation treatment, and obtain the catalyst by drying, calcination and high-temperature reduction pretreatment.
5. The method of claim 4, wherein the catalyst is prepared by a method comprising: The Cu salt and Pd salt are one or both of nitrate or acetate, with nitrate being preferred.
6. The method of claim 4, wherein the catalyst is prepared by the steps of: In the exchange process described in step (1), the concentration of calcium nitrate solution is 1 mol / L, the mass ratio of solution to molecular sieve is 10:1, the exchange is carried out at 80℃, and the cumulative exchange time is 3h; the calcination temperature is 550℃ and the calcination time is 4-6h.
7. The method of claim 4, wherein the catalyst is prepared by the steps of: The impregnation treatment described in step (2) specifically includes the following conditions: using the equal volume impregnation method, Ca-β molecular sieve is placed in a mixed metal salt solution prepared by dissolving Cu salt and Pd salt in deionized water, and left to stand at room temperature for 24 hours.
8. The method of claim 4, wherein the catalyst is prepared by the steps of: The drying temperature in steps (1) and (2) is 100-120℃ and the drying time is 12-24h; the calcination temperature in step (2) is 320-380℃ and the calcination time is 2-4h; the high-temperature reduction pretreatment process in step (2) is to reduce at 230℃ and in a 20% H2-N2 atmosphere for 5-12h.
9. The aldehyde liquid-phase hydrogenation catalyst of claim 1, characterized in that The catalyst is used for the liquid-phase hydrogenation of butyraldehyde or octenaldehyde.