Preparation method and application of high-selectivity boron-containing transition metal catalyst in diglycolamine synthesis
By supporting the boron-containing transition metal catalyst on the aluminum trioxide support, the problems of low catalyst activity and insufficient selectivity in the existing diethylene glycolamine synthesis methods are solved, and diethylene glycolamine synthesis with high conversion and high selectivity are achieved.
Patent Information
- Application Number
- CN202510319564.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2025-05-16
AI Technical Summary
In the existing diethylene glycolamine synthesis methods, the active components of the catalyst are mainly mainly transition metals Ni and Co, and the reaction process is complex, the conversion rate is low, and the selectivity of diethylene glycolamine is low.
A highly selective catalyst was prepared by fully impregnating the salt of metal Co, Cu or Ni with γ-Al2O3, and then adding a borohydride solution to reduce it.
The conversion rate of catalytic diethylene glycol amination reaction can reach more than 90%, the selectivity of diethylene glycol amination to more than 80%, and the preparation method of the catalyst is simple and easy to operate and has low cost.
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Figure CN120001375A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of functional materials, and in particular relates to a boron-containing catalyst for catalytic synthesis of diglycolamine. Background Art
[0002] With the rapid economic development, the massive consumption of fossil fuels such as coal, oil and natural gas has led to increasingly severe energy and environmental problems. The shortage of resources and the massive emission of greenhouse gases such as CO2, which have caused environmental pollution and global warming, have seriously threatened human survival and development and have attracted widespread international attention (Chandramowli SN, Felder FA. Impact of climate change on electricity systems and markets – A review of models and forecasts. Sustainable Energy Technologies & Assessments, 2015, 5: 62-74.). CO2 capture and storage technology (CCS) is one of the most promising technologies for greenhouse gas emission reduction (Li L, Zhao N, Wei W, et al. A review of research progress on CO2, capture, storage, and utilization in Chinese Academy of Sciences. Fuel, 2013, 108(11): 112-130.). CCS technology can be divided into pre-combustion, post-combustion and oxygen-enriched combustion technologies (DU Y. Amine Solvent Development for Carbon Dioxide Capture [D]. Austin: The University of Texas at Austin, 2016.). Among them, post-combustion carbon capture technology is mainly divided into the following methods: physical adsorption, biological fixation, membrane separation and chemical absorption. At present, the chemical absorption method in industry mainly uses the aqueous solution method of organic amines, which uses the chemical reaction between organic amines and CO2 to remove CO2 from flue gas. However, the alcohol amine solution absorption method currently used in industry (such as 30%wt MEA aqueous solution) has the disadvantages of high operating cost, easy corrosion of equipment, easy volatility of solvents, its own toxicity and high regeneration energy consumption. Therefore, it is urgent to find an ideal absorbent with good absorption performance, non-toxicity, low volatility and low regeneration energy consumption.
[0003] Diglycolamine (DGA) is an effective acid gas absorbent, especially suitable for capturing carbon dioxide (CO2). Al-Juaied et al. (Al-Juaied M, Rochelle G T. Thermodynamics and Equilibrium Solubility of Carbon Dioxide in Diglycolamine / Morpholine / Water [J]. Journal of Chemical & Engineering Data, 2006, 51 (2): 708-717.) found through research that when the CO2 concentration is within a certain range, the absorption characteristics of DGA aqueous solution conform to the first-order reaction. At the same time, the study found that adding DGA to morpholine solution can promote its absorption of CO2 (Al-Juaied M, Rochelle G T. Absorption of CO2 inaqueous blends of diglycolamine® and morpholine [J]. Chemical engineering science, 2006, 61 (12): 3830-3837.).
[0004] The reaction of alcohol reagent amination reduction to obtain alcohol amine requires first to generate a carbonyl compound intermediate through a dehydrogenation reaction. The subsequent reaction steps are exactly the same as the reductive amination reaction of the carbonyl compound itself. At present, the active components of supported metal catalysts for the study of alcohol reductive amination reactions are mainly transition metals Ni and Co. (Lei Xianchi. Research on the application of cobalt-based catalysts in the selective reductive amination of ethylene glycol [D]. Xiamen University, 2021.) Xie et al. compared the catalytic performance of nickel and cobalt catalysts for the amination reaction of various diols. The results showed that cobalt-based catalysts have higher activity for short-chain diols. (Xie Z, An H, Zhao X, et al. Catalytic activity of nickel and cobalt foramination of ethylene glycol: Which is better? [J]. Molecular Catalysis, 2022, 522: 112243.) Chen Jian et al. disclosed a method for synthesizing diglycolamine, by loading transition metals on carriers such as alumina and molecular sieves and then calcining to prepare a catalyst, and before the synthesis reaction, the catalyst was filled into a reactor and reduced with hydrogen, thereby obtaining a method for efficiently catalytically synthesizing diglycolamine (Chen Jian, Zhang Shu, Xu Chang, et al. A method for synthesizing diglycolamine [P]. Jiangsu Province: CN202311851648.5, 2024-04-12.). Hu Jiangyu et al. prepared a catalyst by loading nickel on molecular sieves to catalytically synthesize diglycolamine, and the diglycol conversion rate and diglycolamine selectivity were high. At the same time, by doping vanadium into the system, the service life of the catalyst can be further improved, and good catalytic performance can be maintained after continuous operation for 1200 hours (Hu Jiangyu, Chen Guojian, Guo Wenjie, et al. A method for preparing diglycolamine [P]. Shandong Province: CN202311358819.0, 2024-03-29.).
[0005] In the above-mentioned method for catalyzing the reduction amination of diethylene glycol to produce diglycolamine, alumina or molecular sieve is used to load the metal catalyst, and hydrogen is used to reduce and activate the metal catalyst. The reaction process is complicated, the conversion rate is low, and the selectivity of producing diglycolamine is low. Summary of the invention
[0006] The technical problem to be solved by the present invention is to provide a method for preparing a highly selective boron-containing transition metal catalyst in the synthesis of diglycolamine and its application. The boron-containing transition metal catalyst prepared by the present invention can achieve a conversion rate of more than 90% in the catalytic amination reaction of diglycol, and the selectivity of the generated diglycolamine can reach more than 80%.
[0007] The method for preparing a high-selectivity boron-containing transition metal catalyst for diglycolamine synthesis comprises the following steps: (1) completely dissolving a metal salt of Co, Cu or Ni in deionized water, and adding γ-Al2O3 to fully impregnate it; (2) introducing nitrogen to replace the air, and dropwise adding a borohydride solution under ice bath conditions until the reduction is complete; (3) repeatedly washing with deionized water and anhydrous ethanol until neutral; and (4) drying and grinding.
[0008] The metal salt of Co, Cu or Ni in step (1) refers to chloride, sulfate or nitrate, and the metal salt of Co, Cu or Ni can be one or more.
[0009] In step (2), the borohydride is KBH4 or NaBH4, and the concentration of the solution is 0.25 mol·L -1 -2mol·L -1 , pH=10-14.
[0010] The metal chloride of Co, Cu or Ni is CoCl2, CuCl2 or NiCl2; the molar ratio of aluminum oxide to metal chloride is 0.178-2.06:1.
[0011] The concentration of KBH4 or NaBH4 solution in step (2) is 0.25 mol·L -1 -2mol·L -1 , pH=10-14; the molar ratio of solution to metal chloride is 1-10:1.
[0012] Alumina loaded with boron-containing cobalt metal catalyst (CoB / Al2O3): (1) put active alumina into deionized water, disperse it evenly by ultrasonication, and then add CoCl2; (2) introduce nitrogen to replace the air, and add KBH4 solution dropwise under ice bath conditions until the reduction is complete; (3) repeatedly wash with deionized water and anhydrous ethanol; (4) dry and grind to obtain the boron-containing cobalt metal catalyst (CoB / Al2O3) loaded on the active alumina.
[0013] Alumina loaded with boron-containing copper metal catalyst (CuB / Al2O3): (1) put active alumina into deionized water, disperse it evenly with ultrasound, and then add CuCl2; (2) introduce nitrogen to replace the air, and add KBH4 solution dropwise under ice bath conditions until the reduction is complete; (3) repeatedly wash with deionized water and anhydrous ethanol; (4) dry and grind to obtain the boron-containing copper metal catalyst (CuB / Al2O3) loaded on the active alumina.
[0014] Alumina loaded with boron-containing nickel metal catalyst (NiB / Al2O3): (1) Add active alumina into deionized water, disperse it evenly with ultrasonic wave, and then add NiCl2; (2) Pass nitrogen gas to replace the air, and add KBH4 solution dropwise under ice bath condition until the reduction is complete; (3) Wash repeatedly with deionized water and anhydrous ethanol; (4) Dry and grind to obtain the boron-containing nickel metal catalyst (NiB / Al2O3) loaded on the active alumina.
[0015] Alumina loaded with boron-containing nickel-copper metal catalyst (NiCuB / Al2O3): (1) Add active alumina into deionized water, disperse it evenly by ultrasonication, and then add NiCl2 and CuCl2; (2) Pass nitrogen gas to replace the air, and add KBH4 solution dropwise under ice bath conditions until the reduction is complete; (3) Wash repeatedly with deionized water and anhydrous ethanol until neutral; (4) Dry and grind to obtain the boron-containing nickel-copper metal catalyst (NiCuB / Al2O3) loaded on the active alumina.
[0016] Alumina loaded with boron-containing nickel-cobalt metal catalyst (NiCoB / Al2O3): (1) Add active alumina into deionized water, disperse it evenly with ultrasonic wave, and then add NiCl2 and CoCl2; (2) Pass nitrogen gas to replace the air, and add KBH4 solution dropwise under ice bath condition until reduction is complete; (3) Wash repeatedly with deionized water and anhydrous ethanol until neutral; (4) Dry and grind to obtain boron-containing nickel-copper metal catalyst (NiCoB / Al2O3) loaded on active alumina.
[0017] The present invention also provides the use of the catalyst prepared above in catalyzing the reductive amination of diethylene glycol to generate diglycolamine.
[0018] The catalyst prepared by the above method, ammonia solution and diethylene glycol are added to a small batch reactor, and a nitrogen-hydrogen mixed gas is added to the reactor, and magnetic stirring is performed, and the temperature of the reactor is adjusted to 160-240° C. After the reaction is completed, the pressure is released and the sample is taken, and the crude diethylene glycol amine product is obtained by gas chromatography.
[0019] The beneficial effects of adopting the above technical solution are: (1) In the series of boron-containing transition metal catalysts prepared by the present invention, boron can promote the uniform dispersion of transition metals on the carrier, prevent the agglomeration of metal particles, and thus maintain a smaller metal particle size. At the same time, it can adjust the electron density of the transition metal center and change its redox properties, which helps to optimize the reaction path and improve selectivity and activity. The use of boron-containing transition metal catalysts to catalyze the amination reaction of diethylene glycol can achieve a diethylene glycol conversion rate of more than 90%, and the selectivity of diethylene glycol amine can reach more than 80%.
[0020] (2) The catalyst prepared by the present invention is simple and easy to operate, has low cost and good catalytic performance, and can effectively catalyze the synthesis of diglycolamine. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is the gas chromatogram of the synthesis of diglycolamine catalyzed by the CoB / Al2O3 catalyst prepared in Example 1.
[0022] Figure 2 This is the gas chromatogram of the synthesis of diglycolamine catalyzed by the CuB / Al2O3 catalyst prepared in Example 2.
[0023] Figure 3 This is the gas chromatogram of the synthesis of diglycolamine catalyzed by the NiB / Al2O3 catalyst prepared in Example 3.
[0024] Figure 4 This is the gas chromatogram of the synthesis of diglycolamine catalyzed by the NiCuB / Al2O3 catalyst prepared in Example 4.
[0025] Figure 5 This is the gas chromatogram of the synthesis of diglycolamine catalyzed by the NiCoB / Al2O3 catalyst prepared in Example 5. DETAILED DESCRIPTION Example 1
[0026] Accurately weigh 0.5g of active aluminum oxide and put it into deionized water. Ultrasonicate for 5 minutes to make it evenly dispersed, and then add 0.366g of CoCl 2， Soak for two hours. Connect N2 and place the mixture in an ice bath to prepare 0.25 mol·L -1 , 25mL, pH=12 KBH4 solution, was added dropwise into the mixture for reduction, during which the solution was observed to turn black and a large number of black boron-containing cobalt metal nanoparticles were generated. After the reaction, the material was repeatedly washed with deionized water and anhydrous ethanol, and after washing, it was placed in an oven to dry, and after grinding, a boron-containing cobalt metal catalyst (CoB / Al2O3) loaded on active alumina was obtained. Example 2
[0027] Accurately weigh 0.5g of active aluminum oxide and put it into deionized water. Ultrasonicate for 5 minutes to make it evenly dispersed. Then add 0.356g of CuCl2 to the solution and soak it for two hours. Connect N2 and place the mixture in an ice bath to prepare 0.25mol·L -1 , 25mL, pH=12 KBH4 solution, was added dropwise into the mixture for reduction, during which the solution turned black and a large number of black boron-containing copper metal nanoparticles were generated. After the reaction, the material was repeatedly washed with deionized water and anhydrous ethanol, and then placed in an oven to dry. After grinding, a boron-containing copper metal catalyst (CuB / Al2O3) loaded on active alumina was obtained. Example 3
[0028] Accurately weigh 0.5g of active aluminum oxide and put it into deionized water. Ultrasonicate for 5 minutes to make it dispersed evenly. Then add 0.367g of NiCl2 to the solution and soak it for two hours. Connect N2 and place the mixture in an ice bath to prepare 0.25mol·L -1 , 25mL, pH=12 KBH4 solution, was added dropwise into the mixture for reduction, during which the solution was observed to turn black and a large number of black boron-containing nickel metal nanoparticles were generated. After the reaction, the material was repeatedly washed with deionized water and anhydrous ethanol, and after washing, it was placed in an oven to dry, and after grinding, a boron-containing nickel metal catalyst (NiB / Al2O3) loaded on active alumina was obtained. Example 4
[0029] Accurately weigh 0.5g of active aluminum oxide and put it into deionized water. Ultrasonicate for 5 minutes to make it dispersed evenly. Then add 0.178g CuCl2 and 0.1835g NiCl2 to the solution and soak it for two hours. Connect N2 and place the mixture in an ice bath to prepare 0.25mol·L -1 , 25mL, pH=12 KBH4 solution, was added dropwise into the mixture for reduction, during which the solution was observed to turn black, and a large number of black boron-containing nickel-copper metal nanoparticles were generated. After the reaction, it was repeatedly washed with deionized water and anhydrous ethanol, and the material was placed in an oven to dry after washing. After grinding, a boron-containing nickel-copper metal catalyst (NiCuB / Al2O3) loaded on active alumina was obtained. Example 5
[0030] Accurately weigh 0.5g of active aluminum oxide and put it into deionized water. Ultrasonicate for 5 minutes to make it dispersed evenly. Then add 0.183g CoCl2 and 0.1835g NiCl2 to the solution and soak it for two hours. Connect N2 and place the mixture in an ice bath to prepare 0.25mol·L -1 , 25mL, pH=12 KBH4 solution, was added dropwise into the mixture for reduction, during which the solution was observed to turn black, and a large number of black boron-containing nickel-cobalt metal nanoparticles were generated. After the reaction, the material was repeatedly washed with deionized water and anhydrous ethanol, and after washing, it was placed in an oven to dry, and after grinding, a boron-containing nickel-cobalt metal catalyst (NiCoB / Al2O3) loaded on active alumina was obtained. Example 6
[0031] 0.5g of the CoB / Al2O3 catalyst prepared in Example 1, 14ml of 25% ammonia solution and 5.4ml of diethylene glycol were added to a small batch reactor, and 0.4Mpa of nitrogen-hydrogen mixed gas (hydrogen accounts for 10%) was added to the reactor and stirred at 800rpm. At the same time, the temperature of the reactor was adjusted to 170°C. The reaction was carried out for 5 hours, and the pressure was released and sampled. The gas chromatography was used for testing, and the diethylene glycol conversion rate was 92% and the selectivity was 81%. (Chromatographic separation conditions are: the injector and detector are 280°C, the column box is set to continuously heat up, the initial temperature is 50°C, the final temperature is 240°C, and the temperature rises by 10°C per minute.) Example 7
[0032] 0.5g of the CuB / Al2O3 catalyst prepared in Example 2, 14ml of 25% ammonia solution and 5.4ml of diethylene glycol were added to the batch reactor, and 0.4Mpa of nitrogen-hydrogen mixed gas (hydrogen accounts for 10%) was added to the reactor and stirred at 800rpm. At the same time, the temperature of the reactor was adjusted to 170℃. The reaction was carried out for 5 hours, and the pressure was released and sampled. The gas chromatography was used for testing, and the diethylene glycol conversion rate was 92% and the selectivity was 84%. (The chromatographic separation conditions were: the injector and detector were 280℃, the column box was set to continuously heat up, the initial temperature was 50℃, the final temperature was 240℃, and the temperature was increased by 10℃ per minute.) Example 8
[0033] 0.5g of NiB / Al2O3 catalyst prepared in Example 3, 14ml of 25% ammonia solution and 5.4ml of diethylene glycol were added to the batch reactor, and 0.4Mpa of nitrogen-hydrogen mixed gas (hydrogen accounts for 10%) was added to the reactor and stirred at 800rpm. At the same time, the temperature of the reactor was adjusted to 170℃. The reaction was carried out for 5 hours, and the pressure was released and sampled. The gas chromatography was used for testing, and the diethylene glycol conversion rate was 92% and the selectivity was 86%. (The chromatographic separation conditions were: the injector and detector were 280℃, the column box was set to continuously heat up, the initial temperature was 50℃, the final temperature was 240℃, and the temperature was increased by 10℃ per minute.) Example 9
[0034] 0.5g of the NiCuB / Al2O3 catalyst prepared in Example 4, 14ml of 25% ammonia solution and 5.4ml of diethylene glycol were added to the batch reactor, and 0.4Mpa of nitrogen-hydrogen mixed gas (hydrogen accounts for 10%) was added to the reactor and stirred at 800rpm. At the same time, the temperature of the reactor was adjusted to 170℃. The reaction was carried out for 5 hours, and the pressure was released and sampled. The gas chromatography was used for testing, and the diethylene glycol conversion rate was 952% and the selectivity was 88%. (The chromatographic separation conditions were: the injector and detector were 280℃, the column box was set to continuously heat up, the initial temperature was 50℃, the final temperature was 240℃, and the temperature was increased by 10℃ per minute.) Example 10
[0035] 0.5g of the NiCoB / Al2O3 catalyst prepared in Example 5, 14ml of 25% ammonia solution and 5.4ml of diethylene glycol were added to the intermittent reactor, and 0.4Mpa of nitrogen-hydrogen mixed gas (hydrogen accounts for 10%) was added to the reactor and stirred at 800rpm, and the temperature of the reactor was adjusted to 170℃. The reaction was carried out for 5 hours, and the pressure was released and sampled. The gas chromatography was used for testing, and the diethylene glycol conversion rate was 92% and the selectivity was 88%. (The chromatographic separation conditions were: the injector and detector were 280℃, the column box was set to continuously heat up, the initial temperature was 50℃, the final temperature was 240℃, and the temperature was increased by 10℃ per minute).
Claims
1. A method for preparing a highly selective boron-containing transition metal catalyst for diglycolamine synthesis, characterized in that: The method comprises the following steps: (1) completely dissolving the salt of metal Co, Cu or Ni into deionized water, and adding γ-Al2O3 to fully impregnate it; (2) introducing nitrogen to replace the air, and adding borohydride solution dropwise under ice bath conditions until the reduction is complete; (3) repeatedly washing with deionized water and anhydrous ethanol until neutral; and (4) drying and grinding.
2. The method for preparing the catalyst according to claim 1, characterized in that: The metal salt of Co, Cu or Ni in step (1) refers to chloride, sulfate or nitrate.
3. The method for preparing the catalyst according to claim 1, characterized in that: In step (2), the borohydride is KBH4 or NaBH4, and the concentration of the solution is 0.25 mol·L -1 -2mol·L -1 , pH=10-14.
4. The method for preparing a catalyst according to any one of claims 1 to 3, characterized in that: (1) Add active alumina into deionized water, disperse it evenly with ultrasound, and then add CoCl2; (2) Pass nitrogen to replace the air, and add KBH4 solution dropwise under ice bath conditions until the reduction is complete; (3) Wash repeatedly with deionized water and anhydrous ethanol until neutral; (4) Dry and grind to obtain a boron-containing cobalt metal catalyst (CoB / Al2O3) loaded on active alumina.
5. The method for preparing a catalyst according to any one of claims 1 to 3, characterized in that: (1) Add active alumina into deionized water, disperse it evenly with ultrasound, and then add CuCl2; (2) Pass nitrogen to replace the air, and add KBH4 solution dropwise under ice bath conditions until the reduction is complete; (3) Wash repeatedly with deionized water and anhydrous ethanol until neutral; (4) Dry and grind to obtain a boron-containing copper metal catalyst (CuB / Al2O3) loaded on active alumina.
6. The method for preparing a catalyst according to any one of claims 1 to 3, characterized in that: (1) Add active alumina into deionized water, disperse it evenly with ultrasound, and then add NiCl2; (2) Pass nitrogen to replace the air, and add KBH4 solution dropwise under ice bath conditions until the reduction is complete; (3) Wash repeatedly with deionized water and anhydrous ethanol until neutral; (4) Dry and grind to obtain a boron-containing nickel metal catalyst (NiB / Al2O3) loaded on active alumina.
7. The method for preparing a catalyst according to any one of claims 1 to 3, characterized in that: (1) Add active alumina into deionized water, disperse it evenly with ultrasonic wave, and then add NiCl2 and CuCl2; (2) Pass nitrogen to replace the air, and add KBH4 solution dropwise under ice bath condition until the reduction is complete; (3) Wash repeatedly with deionized water and anhydrous ethanol until neutral; (4) Dry and grind to obtain boron-containing nickel-copper metal catalyst (NiCuB / Al2O3) loaded on active alumina.
8. The method for preparing a catalyst according to any one of claims 1 to 3, characterized in that: (1) Add active alumina into deionized water, disperse it evenly with ultrasonic wave, and then add NiCl2 and CoCl2; (2) Pass nitrogen to replace the air, and add KBH4 solution dropwise under ice bath condition until the reduction is complete; (3) Wash repeatedly with deionized water and anhydrous ethanol until neutral; (4) Dry and grind to obtain boron-containing nickel-cobalt metal catalyst (NiCoB / Al2O3) loaded on active alumina.
9. Use of the catalyst prepared according to any one of claims 1 to 3 in catalyzing the reductive amination of diethylene glycol to produce diglycolamine.