Preparation method for supported nickel-based catalyst, and polyetheramine prepared from catalyst
The improved process for preparing supported nickel-based catalysts by using a kneading molding method and pore-expanding agents solves the problems of uneven dispersion of active components and high cost, achieving the synthesis of highly active and selective polyetheramines while reducing by-product generation and production costs.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ZHEJIANG HUANGMA TECH CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-21
AI Technical Summary
Existing polyetheramine synthesis catalysts suffer from problems such as uneven dispersion of active components, poor mechanical strength, high cost, and low utilization of active metals. Traditional impregnation methods are complex to prepare and cannot improve catalyst activity.
An active metal source was combined with an alumina support using a kneading molding method. A supported nickel-based catalyst was prepared by combining a pore expander and an impregnation method. The active metal component was added during the molding process by kneading, and the pore structure was improved by using a pore expander. Another part of the metal component was loaded by the impregnation method.
It improves the metal loading and pore structure stability of the catalyst, significantly enhances the conversion rate of polyol ethers and the selectivity of primary amines, reduces the generation of by-products, lowers production costs, and simplifies the process for industrialization.
Smart Images
Figure PCTCN2025098238-FTAPPB-I100001 
Figure PCTCN2025098238-FTAPPB-I100002 
Figure PCTCN2025098238-FTAPPB-I100003
Abstract
Description
A method for preparing a supported nickel-based catalyst and its application in the preparation of polyetheramines Technical Field
[0001] This invention belongs to the field of fine chemical synthesis technology, specifically relating to a method for preparing a supported nickel-based catalyst and the preparation of polyetheramines using it. Background Technology
[0002] Polyetheramines (PEAs) are compounds with a flexible polyether backbone, capped at one end with an amino or amine group (generally a secondary, primary, or polyamine group containing active hydrogen). As functional chemicals, they have important applications in various fields such as chemical engineering and pharmaceuticals. Currently, the main methods for synthesizing polyetheramines include catalytic amination, leaving group method, hydrolysis, aminophenoxy method, aminobutyrate method, and cyanoalkylation method. Among these, catalytic amination has advantages such as high raw material utilization, low environmental pollution, high conversion rate and good selectivity, easy separation and purification of the synthesized product, and high product purity. Moreover, this method involves only one step of reaction, making the process simple and the preferred method for large-scale industrial continuous production by foreign chemical companies. Currently, there is a relative shortage of polyetheramine products, especially low molecular weight polyetheramines, which to some extent restricts their widespread application.
[0003] Currently, the more mature fixed-bed catalysts for hydroammoniation can be broadly classified into three categories: copper-based catalysts, noble metal catalysts, and nickel-based catalysts. The preparation processes can be broadly categorized into two types: co-precipitation and impregnation. Co-precipitation is a widely used process for preparing polyetheramine catalysts. It involves adding a precipitant to a mixed metal salt solution, causing two or more cations in the solution to precipitate together, forming a precipitate mixture or solid solution precursor. This is followed by filtration, washing, and thermal decomposition to obtain a composite oxide. However, the properties of the precipitate largely determine the properties of the catalyst, requiring careful determination and strict control of various factors, and demanding high operational skills. The synthesis process consumes a significant amount of alkali, is influenced by complex factors, requires efficient washing and filtration equipment, and generates substantial amounts of wastewater. Furthermore, while co-precipitated bulk catalysts meet mechanical strength requirements, their surface active site density is low, failing to fully utilize the advantages of high-content active metal components, reducing the utilization rate of active metals, and increasing the catalyst preparation cost.
[0004] Therefore, currently used polyetheramine synthesis catalysts are typically obtained using the impregnation method. The specific steps mainly involve first preparing an alumina support, then impregnating the support with active components such as Ni and Co, and finally drying and calcining. However, the two drying and calcination processes (including one during the preparation of the molded support) result in a certain loss of pore volume and specific surface area, making the process complex and the catalyst cost relatively high. As is well known, the impregnation method is based on the active component being impregnated onto a porous support in the form of a salt solution and permeating into the inner surface. Due to the limitations of this method, the loading of the active component is limited, and the catalyst activity cannot be improved accordingly. Industrial catalyst development should consider both cost and time and energy savings. Coupled with the molding process to prepare molded catalysts is a good solution to this problem. The traditional dry-mixing method for catalyst preparation involves mixing, kneading, molding, drying, and calcining the active component, support precursor, and binder. Catalysts prepared by dry mixing in industry generally suffer from uneven dispersion of active components and poor catalyst strength. Therefore, researching new catalyst preparation technologies is of great significance for reducing catalyst production costs and improving catalyst activity. Summary of the Invention
[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a method for preparing a supported nickel-based catalyst and for preparing polyetheramines using the catalyst. The supported nickel-based catalyst prepared by the present invention has high activity and low cost; its use in the preparation of polyetheramines can significantly improve the conversion rate of polyol ethers and the selectivity of primary amines, while reducing the generation of byproducts.
[0006] This invention provides a method for preparing a supported nickel-based catalyst.
[0007] Specifically, a method for preparing a supported nickel-based catalyst includes the following steps:
[0008] S1. Using a first active metal source, aluminum hydroxide dry adhesive powder, extrusion aid, pore expander and silica sol as raw materials, an alumina carrier containing active metal components is prepared by kneading molding.
[0009] S2. An impregnation solution is prepared using a second active metal source, and then the alumina support prepared in step (1) is impregnated and calcined to obtain a supported nickel-based catalyst.
[0010] In steps S1 and S2, both the first active metal source and the second active metal source include a nickel source, a platinum source, a copper source, and a cobalt source. The first active metal source and the second active metal source include, but are not limited to, nitrates, sulfates, organic salts, chlorides, etc., of the aforementioned metals, preferably nitrates of the metals.
[0011] Preferably, in the first active metal source, the molar ratio of nickel, platinum, copper, and cobalt in the nickel source, platinum source, copper source, and cobalt source is 1:(0.0008-0.002):(0.06-0.08):(0.05-0.2).
[0012] Preferably, in the second active metal source, the molar ratio of nickel, platinum, copper, and cobalt in the nickel source, platinum source, copper source, and cobalt source is 1:(0.0008-0.002):(0.06-0.08):(0.05-0.2).
[0013] In steps S1 and S2, the first active metal source and the second active metal source also independently include at least one of zirconium source, lanthanum source, and rhenium source.
[0014] The preparation process in step S1 includes either of the following two methods:
[0015] (1) Dissolve the first active metal source in water to prepare a kneading solution; take aluminum hydroxide dry adhesive powder, add extrusion aid, pore expander and silica sol, mix evenly, add the kneading solution and knead, then shape, dry and calcine to prepare an alumina carrier containing active metal components.
[0016] (2) Dissolve the first active metal source in water, add silica sol, and prepare a kneading solution; take aluminum hydroxide dry glue powder, add extrusion aid and pore expander, mix evenly, add the kneading solution, knead, and then shape, dry and calcine to prepare an alumina carrier containing active metal components.
[0017] In the kneading and molding process, the silica sol is added in two ways: one is to first add the silica sol to aluminum hydroxide dry adhesive powder mixed with extrusion aid and pore expander, mix evenly, and then add the kneading solution; the second method is to first mix and dissolve the silica sol with the first active metal source, and then add it to the aluminum hydroxide dry adhesive powder mixed with extrusion aid and pore expander. From the results, the carrier prepared by the first method has a superior pore structure.
[0018] Preferably, the silica sol includes alkaline silica sol or acidic silica sol.
[0019] Preferably, the extrusion aid includes at least one of guar gum powder, starch, cellulose, and charcoal powder.
[0020] Preferably, the amount of the extrusion aid added is 1%-30% of the mass of the aluminum hydroxide dry adhesive powder; more preferably, the amount of the extrusion aid added is 3%-15%, 5%, 6%, 8%, 10%, 12%, etc., of the mass of the aluminum hydroxide dry adhesive powder.
[0021] Preferably, the pore-expanding agent is carbon black. During the molding process, using carbon black as a pore-expanding agent is beneficial for expanding the pores of the carrier and improving the concentration of pore distribution.
[0022] Preferably, the amount of the pore-expanding agent added is 1%-30% of the mass of the aluminum hydroxide dry adhesive powder; more preferably, the amount of the pore-expanding agent added is 3%-15%, 5%, 6%, 8%, 10%, 12%, etc., of the mass of the aluminum hydroxide dry adhesive powder.
[0023] In method (1) or method (2), a colloidal solvent is added when preparing the kneading solution. The colloidal solvent is selected from at least one of inorganic acids, organic acids, and strongly acidic anionic aluminum salts. For example, nitric acid, hydrochloric acid, oxalic acid, formic acid, acetic acid, citric acid, aluminum nitrate, etc., or a combination of several colloidal solvents. The addition of the colloidal solvent is beneficial to the kneading and molding of the carrier.
[0024] In method (1) or method (2), the drying process is as follows: drying at 100-130°C for 2-12 hours, followed by calcination at 400-500°C for 2-8 hours.
[0025] In method (1) or method (2), the roasting process is: roasting at 400-500℃ for 2-8 hours.
[0026] In method (1) or method (2), the forming process is as follows: the mixed material is extruded into strips on an extruder. The shape of the carrier can be adjusted by changing the perforated plate of the extruder, and its shape can be cylindrical or irregular (such as clover, four-leaf clover, five-toothed ball).
[0027] Preferably, in step S2, the impregnation process is as follows: the alumina carrier is placed in the impregnation solution and impregnated for 20-60 minutes at 35-45°C under rotation.
[0028] Preferably, in step S2, the number of impregnations is 1-5 times; more preferably, in step S2, the number of impregnations is 2-3 times. When the number of impregnations is greater than 1 time, the process is as follows: the alumina support is impregnated once and calcined once, the calcined catalyst support is used as a support again, and the impregnation solution is impregnated and calcined again until the number of impregnations is reached.
[0029] Preferably, in step S2, the roasting process is: roasting at 400-500℃ for 3-8 hours.
[0030] Preferably, the inert gas is selected from nitrogen, helium, neon, argon, or krypton. When a mixed atmosphere of inert gas and hydrogen is used, the volume percentage of the inert gas is 5% to 95%.
[0031] Preferably, in step S2, after the calcination process, a reduction treatment and a passivation treatment are further included. The reduction treatment is performed by reducing the gas at 300°C to 550°C for 40 to 70 hours in a pure hydrogen atmosphere or a mixture of an inert gas and hydrogen. The passivation treatment is performed by surface passivation using an oxidizing gas for 6 to 18 hours, wherein the oxidizing gas includes one or more of oxygen, water vapor, carbon dioxide, and air.
[0032] The present invention also provides a method for preparing polyetheramine.
[0033] Specifically, a method for preparing polyetheramine involves synthesizing polyetheramine using a supported nickel-based catalyst prepared by the above method.
[0034] Traditional impregnation methods for catalyst preparation involve impregnating a calcined support with a metal salt solution. After calcination, the pores of the support collapse, resulting in a decrease in specific surface area and pore volume. Furthermore, the active components on the surface and in the pores of the support decompose into oxides after drying and calcination, and some pores of the support become blocked by the active components, leading to a loss of internal surface area and uneven dispersion of the active components.
[0035] This invention first utilizes a kneading method to add active metal salts to raw materials, followed by a one-step molding, drying, and calcination process to obtain a support. During the calcination of the support, the decomposition and dispersion of the active metal salts occur simultaneously with the decomposition of the raw materials. The active metals remain within the pores of the support, providing support for the catalyst structure. The molding process is improved using carbon black pore-expanding agents. A portion of the metal component is loaded through kneading, while the other portion is loaded through a coupled impregnation method. This approach maintains the catalyst's pore structure while simultaneously increasing the metal loading.
[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0037] (1) The supported nickel-based catalyst provided by the present invention increases the metal loading of the catalyst by adding a certain amount of active metal components in a kneading manner during the forming process of the alumina support; at the same time, the pore structure of the catalyst is maintained at a relatively stable stage by modifying it with a pore expander, so that the catalyst activity can be significantly improved after the support containing active metal components is impregnated with metal solution.
[0038] (2) This invention employs a novel kneading method to prepare a support containing active metals, followed by a comprehensive impregnation method to increase the loading of active metals. The catalyst prepared by this method has the characteristics of large pore volume, large specific surface area, and uniform distribution of active components; using it to prepare polyetheramines can significantly improve the conversion rate of polyol ethers and the selectivity of primary amines, while reducing the generation of by-products.
[0039] (3) Compared with the coprecipitation method, the preparation method provided by the present invention has lower production cost, simpler process, and is easier to industrialize. Detailed Implementation
[0040] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.
[0041] Unless otherwise specified, the raw materials, reagents or apparatus used in the following examples and comparative examples are available from conventional commercial sources or can be obtained by existing known methods.
[0042] Example 1
[0043] A method for preparing a supported nickel-based catalyst includes the following steps:
[0044] (1) Preparation of mixed solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, 0.1g of chloroplatinic acid (39% Pt), and 5g of nitric acid and dissolve them in 90g of deionized water. Stir and mix to obtain a mixed solution.
[0045] (2) Kneading and molding: Weigh 80g of aluminum hydroxide dry adhesive powder, add 5g of hydroxymethyl cellulose and 5g of carbon black and mix evenly. First, add an aqueous solution of silica sol (7.7mL of silica sol dissolved in 15mL of water, of which the silica sol is 30% alkaline silica sol with a silica particle size of 10-30nm), knead evenly to make it into a fine powder, and obtain kneaded fine powder. Then add the kneading solution to the kneaded fine powder and knead again until it is kneaded into a uniform paste-like plastic material. Extrude it into 3mm strips on an extruder and dry it in a drying oven at 110℃ for 3 hours. Then, calcine it in a high-temperature furnace at 550℃ for 4 hours to obtain an alumina carrier containing active metal components.
[0046] (3) Preparation of impregnation solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, and 0.1g of chloroplatinic acid (39% Pt), and dissolve them in 30g of deionized water.
[0047] (4) Equal volume impregnation: 82g of the alumina support containing active metal components prepared in step (2) is impregnated in the impregnation solution prepared in step (3). The mixture is then impregnated in a rotary evaporator at 40°C for 30 minutes. After adsorption equilibrium is reached, the temperature is raised to 90°C, vacuum dehydrated and dried, and then calcined at 400°C for 4 hours. The calcined catalyst support is then used as a support again, and the impregnation solution is prepared again in the same proportion for a second impregnation, adsorption and calcination. Finally, the calcined oxidized catalyst is placed in a reduction furnace at a hydrogen space velocity of 400 h⁻¹. -1The catalyst was reduced at 420℃ for 60 hours. After reduction, steam was introduced to passivate the catalyst surface for 10 hours, yielding a nickel-based supported catalyst.
[0048] Example 2
[0049] A method for preparing a supported nickel-based catalyst includes the following steps:
[0050] (1) Preparation of mixed solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, 0.1g of chloroplatinic acid (39% Pt), and 5g of nitric acid and dissolve them in 90g of deionized water. Add 7.7mL of silica sol (30% alkaline silica sol, silica particle size 10-30nm) dropwise and stir to mix.
[0051] (2) Mixing and molding: Weigh 80g of aluminum hydroxide dry adhesive powder, add 5g of hydroxymethyl cellulose and 5g of carbon black to it, add the above-prepared solution to the aluminum hydroxide dry adhesive powder containing hydroxymethyl cellulose and carbon black, mix and knead into a uniform paste-like plastic, then extrude it into 3mm strips on an extruder, dry it in a drying oven at 110℃ for 3 hours, and then calcine it in a high-temperature furnace at 550℃ for 4 hours to obtain an alumina carrier containing active metal components.
[0052] (3) Preparation of impregnation solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, and 0.1g of chloroplatinic acid (39% Pt), and dissolve them in 30g of deionized water.
[0053] (4) Equal-volume impregnation: 82g of the alumina support containing active metal components prepared in step (2) was impregnated in the impregnation solution prepared in step (3). The impregnation was carried out in a rotary evaporator at 40°C for 30 min by rotating in a water bath. After adsorption equilibrium was reached, the temperature was raised to 90°C, vacuum dehydrated and dried, and then calcined at 400°C for 4 h. The calcined catalyst support was then used as a support again, and the impregnation solution was prepared again in the same proportion for a second impregnation, adsorption and calcination. Finally, the calcined oxidized catalyst was reduced in a reduction furnace at 420°C for 60 h at a hydrogen space velocity of 400 h⁻¹. After the reduction was completed, water vapor was introduced to passivate the catalyst surface for 10 h to obtain a nickel-based supported catalyst.
[0054] Example 3
[0055] A method for preparing a supported nickel-based catalyst includes the following steps:
[0056] (1) Preparation of mixed solution: Weigh 30g of nickel nitrate hexahydrate, 3.25g of cobalt nitrate hexahydrate, 1.95g of copper nitrate pentahydrate, 0.05g of chloroplatinic acid (39% Pt), and 2.5g of nitric acid and dissolve them in 45g of deionized water. Stir and mix to obtain a mixed solution.
[0057] (2) Kneading and molding: Weigh 80g of aluminum hydroxide dry adhesive powder, add 5g of hydroxymethyl cellulose and 5g of carbon black and mix evenly. First, add an aqueous solution of silica sol (7.7mL of silica sol dissolved in 15mL of water, of which the silica sol is 30% alkaline silica sol with a silica particle size of 10-30nm), knead evenly to make it into a fine powder, and obtain kneaded fine powder. Then add the kneading solution to the kneaded fine powder and knead again until it is kneaded into a uniform paste-like plastic material. Extrude it into 3mm strips on an extruder and dry it in a drying oven at 110℃ for 3 hours. Then, calcine it in a high-temperature furnace at 550℃ for 4 hours to obtain an alumina carrier containing active metal components.
[0058] (3) Preparation of impregnation solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, and 0.1g of chloroplatinic acid (39% Pt), and dissolve them in 30g of deionized water.
[0059] (4) Equal volume impregnation: 82g of the alumina support containing active metal components prepared in step (2) is impregnated in the impregnation solution prepared in step (3). The mixture is then impregnated in a rotary evaporator at 40°C for 30 minutes. After adsorption equilibrium is reached, the temperature is raised to 90°C, vacuum dehydrated and dried, and then calcined at 400°C for 4 hours. The calcined catalyst support is then used as a support again, and the impregnation solution is prepared again in the same proportion for a second impregnation, adsorption and calcination. Finally, the calcined oxidized catalyst is placed in a reduction furnace at a hydrogen space velocity of 400 h⁻¹. -1 The catalyst was reduced at 420℃ for 60 hours. After reduction, steam was introduced to passivate the catalyst surface for 10 hours, yielding a nickel-based supported catalyst.
[0060] Example 4
[0061] A method for preparing a supported nickel-based catalyst includes the following steps:
[0062] (1) Preparation of mixed solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, 0.1g of chloroplatinic acid (39% Pt), and 5g of nitric acid and dissolve them in 90g of deionized water. Stir and mix to obtain a mixed solution.
[0063] (2) Kneading and molding: Weigh 80g of aluminum hydroxide dry adhesive powder, add 5g of hydroxymethyl cellulose and 5g of carbon black and mix evenly. First, add an aqueous solution of silica sol (7.7mL of silica sol dissolved in 15mL of water, of which the silica sol is 30% alkaline silica sol with a silica particle size of 10-30nm), knead evenly to make it into a fine powder, and obtain kneaded fine powder. Then add the kneading solution to the kneaded fine powder and knead again until it is kneaded into a uniform paste-like plastic material. Extrude it into 3mm strips on an extruder and dry it in a drying oven at 110℃ for 3 hours. Then, calcine it in a high-temperature furnace at 550℃ for 4 hours to obtain an alumina carrier containing active metal components.
[0064] (3) Preparation of impregnation solution: Weigh 30g of nickel nitrate hexahydrate, 3.25g of cobalt nitrate hexahydrate, 1.95g of copper nitrate pentahydrate, and 0.05g of chloroplatinic acid (39% Pt), and dissolve them in 15g of deionized water.
[0065] (4) Equal volume impregnation: 82g of the alumina support containing active metal components prepared in step (2) is impregnated in the impregnation solution prepared in step (3). The mixture is then impregnated in a rotary evaporator at 40°C for 30 minutes. After adsorption equilibrium is reached, the temperature is raised to 90°C, vacuum dehydrated and dried, and then calcined at 400°C for 4 hours. The calcined catalyst support is then used as a support again, and the impregnation solution is prepared again in the same proportion for a second impregnation, adsorption and calcination. Finally, the calcined oxidized catalyst is placed in a reduction furnace at a hydrogen space velocity of 400 h⁻¹. -1 The catalyst was reduced at 420℃ for 60 hours. After reduction, steam was introduced to passivate the catalyst surface for 10 hours, yielding a nickel-based supported catalyst.
[0066] Comparative Example 1
[0067] A method for preparing an alumina support containing an active metal component includes the following steps:
[0068] (1) Preparation of mixed solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, 0.1g of chloroplatinic acid (39% Pt) and 5g of nitric acid and dissolve them in 90g of deionized water.
[0069] (2) Mixing and molding: Weigh 80g of aluminum hydroxide dry adhesive powder, add 5g of hydroxymethyl cellulose to it, add the mixing solution to the aluminum hydroxide dry adhesive powder containing hydroxymethyl cellulose, mix and knead into a uniform paste-like plastic, then extrude it into a 3mm strip on an extruder, dry it in a drying oven at 110℃ for 3 hours, and then calcine it in a high-temperature furnace at 550℃ for 4 hours to obtain an alumina carrier containing active metal components.
[0070] Comparative Example 2
[0071] A method for preparing an alumina support containing an active metal component includes the following steps:
[0072] (1) Preparation of mixed solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, 0.1g of chloroplatinic acid (39% Pt), and 5g of nitric acid and dissolve them in 90g of deionized water. Stir and mix to obtain a mixed solution.
[0073] (2) Kneading and molding: Weigh 80g of aluminum hydroxide dry adhesive powder, add 5g of hydroxymethyl cellulose and 5g of carbon black and mix evenly. First, add an aqueous solution of silica sol (7.7mL of silica sol dissolved in 15mL of water, of which the silica sol is 30% alkaline silica sol with a silica particle size of 10-30nm), knead evenly to make it into a fine powder, and obtain kneaded fine powder. Then add the kneading solution to the kneaded fine powder and knead again until it is kneaded into a uniform paste-like plastic material. Extrude it into 3mm strips on an extruder and dry it in a drying oven at 110℃ for 3 hours. Then, calcine it in a high-temperature furnace at 550℃ for 4 hours to obtain an alumina carrier containing active metal components.
[0074] Comparative Example 3
[0075] A method for preparing an alumina support containing an active metal component includes the following steps:
[0076] (1) Preparation of mixed solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, 0.1g of chloroplatinic acid (39% Pt), and 5g of nitric acid and dissolve them in 90g of deionized water. Add 7.7mL of silica sol (30% alkaline silica sol, silica particle size 10-30nm) dropwise and stir to mix.
[0077] (2) Mixing and molding: Weigh 80g of aluminum hydroxide dry adhesive powder, add 5g of hydroxymethyl cellulose and 5g of carbon black to it, add the above-prepared solution to the aluminum hydroxide dry adhesive powder containing hydroxymethyl cellulose and carbon black, mix and knead into a uniform paste-like plastic, then extrude it into 3mm strips on an extruder, dry it in a drying oven at 110℃ for 3 hours, and then calcine it in a high-temperature furnace at 550℃ for 4 hours to obtain an alumina carrier containing active metal components.
[0078] Comparative Example 4
[0079] A method for preparing a nickel-based supported catalyst includes the following steps:
[0080] (1) Preparation of pure alumina carrier: Weigh 200g of aluminum hydroxide dry adhesive powder, add 10g of hydroxymethyl cellulose to it, dilute 4g of nitric acid in 160mL of deionized water, add it to the aluminum hydroxide dry adhesive powder containing hydroxymethyl cellulose, knead it into a uniform paste-like plastic, extrude it into 3mm strips on an extruder, dry it in a drying oven at 110℃ for 3 hours, and then calcine it in a high-temperature furnace at 550℃ for 4 hours to obtain pure alumina carrier.
[0081] (2) Preparation of impregnation solution: Weigh 60g of nickel nitrate hexahydrate, 6.5g of cobalt nitrate hexahydrate, 3.9g of copper nitrate pentahydrate, and 0.1g of chloroplatinic acid (39% Pt), and dissolve them in 42g of deionized water.
[0082] (3) Equal volume impregnation: 65g of the pure alumina support obtained in step (1) is immersed in the impregnation solution obtained in step (2), and impregnated in a water bath at 40°C for 30 minutes. After adsorption equilibrium is reached, the temperature is raised to 90°C, vacuum dehydrated and dried, and then calcined at 400°C for 4 hours. Then, the calcined catalyst support is used as a support again, and the impregnation solution is prepared again in the same proportion for a second impregnation, adsorption and calcination. Finally, the calcined oxidized catalyst is placed in a reduction furnace at a hydrogen space velocity of 400 h⁻¹. -1 The catalyst was reduced at 420℃ for 60 hours. After reduction, steam was introduced to passivate the catalyst surface for 10 hours, yielding a nickel-based supported catalyst.
[0083] Product effectiveness test
[0084] (1) Physical adsorption characterization tests were performed on the nickel-based supported catalysts or alumina supports containing active metal components prepared in Examples 1-4 and Comparative Examples 1-4, including specific surface area, pore size, and pore volume. Specific characterization data are shown in Table 1.
[0085] Table 1. Physicoadsorption characterization data
[0086] Analyzing the data in Table 1, as shown in Comparative Examples 1 and 4, the specific surface area of the alumina supported catalyst containing active metal components prepared by the kneading method in Comparative Example 1 is higher than that of the catalyst prepared by the impregnation method in Comparative Example 4. This is because the catalyst prepared by the kneading method involves adding a metal salt solution to the raw material and then molding, drying, and calcining it in one step. During the calcination process, the decomposition and dispersion of the active metal salt component occur simultaneously with the decomposition of the raw material. The active component remains within the pores of the support, providing structural support for the catalyst. Therefore, the kneading method catalyst has a larger specific surface area. In contrast, the catalyst prepared by the impregnation method involves impregnating the calcined support with a metal salt solution. After a second calcination, the pores of the support collapse, resulting in a decrease in specific surface area and pore volume. Furthermore, the active components on the surface and in the pores of the support decompose into oxides during drying and calcination, and some pores of the support are blocked by the active components, leading to a loss of internal surface area and uneven dispersion of the active components.
[0087] Comparative Examples 1 and 2 show that the alumina support containing active metal components prepared by kneading with carbon black as a pore expander in Comparative Example 2, compared to the alumina support containing active metal components prepared by kneading without a pore expander in Comparative Example 1, improves the pore structure of the catalyst. The pore-expanding principle of physical pore expanders such as carbon black is that during calcination, the pore expander, encapsulated in aluminum hydroxide dry adhesive powder, oxidizes into gas and escapes, releasing the space it originally occupied, leading to an increase in the specific surface area, pore volume, and pore size of the support. The pore-expanding effect of the pore expander molecules is related to the kinetic diameter of the pore expander molecules. After adding carbon black, the pore size within the support range increases, basically consistent with the particle size of the carbon black used, which Comparative Example 2 verifies.
[0088] Comparative Examples 2 and 3 show that the aluminum hydroxide dry adhesive powder mixed with extrusion aid and carbon black in Comparative Example 2, where the silica sol was first added to the powder, exhibits a superior pore structure compared to the alumina support containing active metal components prepared by adding the silica sol to a metal mixed solution in Comparative Example 3. This is because the alkaline silica sol may have undergone a neutralization reaction with the metal salt solution, resulting in uneven distribution of the silica sol and metal salt in the catalyst.
[0089] In Examples 1 and 2, the alumina supports containing active metal components prepared in Comparative Examples 2 and 3 were further impregnated with metal solutions and then calcined and reduced to obtain nickel-based supported catalysts. After further impregnation and calcination and reduction, the specific surface area, pore size, and pore volume of the materials decreased slightly.
[0090] (2) The metal elements supported on the nickel-based supported catalysts or alumina supports containing active metal components prepared in Examples 1-4 and Comparative Examples 1-4 were analyzed. The metal element analysis and characterization data are shown in Table 2.
[0091] Table 2. Characterization data of loaded metal elements
[0092] Analysis of the data in Table 2, as shown in Comparative Example 4 and Example 1, reveals that coupling the loading and molding process in the preparation of the shaped catalyst can significantly increase the loading of active metals. In Comparative Example 4, prepared by the impregnation method, the catalyst's pores collapsed after two drying and calcination processes, resulting in a decrease in specific surface area and pore volume. Since equal-volume impregnation is based on the active component being impregnated onto the porous support in the form of a salt solution and penetrating to the inner surface, the loading of the active component cannot be further increased through multiple impregnations due to limitations in water absorption. Comparing Examples 1 and 2 with Comparative Examples 2 and 3, it is evident that the kneaded catalyst modified with carbon black pore-expanding agent, by loading a portion of the metal component through kneading while simultaneously loading the other portion through impregnation, improves the metal loading while maintaining the catalyst's pore structure.
[0093] (3) Catalyst performance evaluation
[0094] The catalytic performance of nickel-based supported catalysts or alumina supports containing active metal components prepared in Examples 1-4 and Comparative Examples 1-4 was evaluated. Polypropylene oxide diamine (D-230) was synthesized using each group of nickel-based supported catalysts or alumina supports containing active metal components. The specific process is as follows: A fixed-bed reactor was loaded with 30 mL of catalyst or alumina support in a random packing manner. Reduction was performed at 250°C using a mixture of 10% hydrogen and 90% nitrogen for 12 h. After reduction, the temperature was lowered to 200°C, the system pressure was increased to 15 MPa, and feeding was initiated. The PPG-230 (polypropylene glycol ether) space velocity was 0.5 h⁻¹. -1 The molar ratio of liquid ammonia to PPG-230 was 8:1, and the molar ratio of hydrogen to PPG-230 was 0.8:1. Excess ammonia and water in the reactants were removed by distillation, and the mixture was analyzed by gas chromatography. Samples were taken for analysis after 60 hours.
[0095] The method for determining the total amine value is as follows: the product is titrated with a 0.5 mol / L hydrochloric acid solution, and the total amine value of the product can be calculated from the mass of hydrochloric acid consumed.
[0096] Method for determining secondary / tertiary amine values: Mix the product with an equal mass of salicylaldehyde and stir for 2 hours. Then titrate the product with 0.5 mol / L hydrochloric acid solution. The sum of the secondary and tertiary amine values of the product can be calculated by the mass of hydrochloric acid consumed.
[0097] Primary amine selectivity = (total amine value - secondary / tertiary amine value) / total amine value × 100%.
[0098] Alcohol conversion rate = Total amine value of product / Total hydroxyl value of raw materials × 100%.
[0099] The results of the catalyst activity evaluation for each group are shown in Table 3.
[0100] Table 3. Results of catalyst activity evaluation for each group
[0101] As shown in Table 3, the catalysts prepared in Examples 1-4 of this invention exhibit significantly better overall activity than the catalyst in Comparative Example 4. The nickel-based supported catalyst prepared in this invention significantly improves the conversion rate of PPG-230 and the selectivity of primary amines, indicating a low level of hydrogenolysis byproduct formation. Therefore, the nickel-based supported catalyst prepared in this invention is an ideal catalyst for the synthesis of polyetheramines.
[0102] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.
Claims
1. A process for the preparation of a supported nickel-based catalyst, characterized in that, Includes the following steps: S1. Using a first active metal source, aluminum hydroxide dry adhesive powder, extrusion aid, pore expander and silica sol as raw materials, an alumina carrier containing active metal components is prepared by kneading molding. S2. An impregnation solution is prepared using a second active metal source, and then the alumina support prepared in step (1) is impregnated and calcined to obtain a supported nickel-based catalyst. In steps S1 and S2, both the first active metal source and the second active metal source include a nickel source, a platinum source, a copper source, and a cobalt source.
2. The production method according to claim 1, characterized by, The preparation process in step S1 includes either of the following two methods: (1) Dissolve the first active metal source in water to prepare a kneading solution; take aluminum hydroxide dry adhesive powder, add extrusion aid, pore expander and silica sol, mix evenly, add the kneading solution and knead, then shape, dry and calcine to prepare an alumina carrier containing active metal components. (2) Dissolve the first active metal source in water, add silica sol, and prepare a kneading solution; take aluminum hydroxide dry glue powder, add extrusion aid and pore expander, mix evenly, add the kneading solution, knead, and then shape, dry and calcine to prepare an alumina carrier containing active metal components.
3. The production method according to claim 1 or 2, characterized by, The silica sol includes alkaline silica sol or acidic silica sol.
4. The production method according to claim 1 or 2, characterized by, The extrusion aid includes at least one of guar gum powder, starch, cellulose, and charcoal powder.
5. The production method according to claim 1 or 2, characterized by, The pore-expanding agent is carbon black.
6. The method of claim 2, wherein, In method (1) or method (2), a pectin is added when preparing the kneaded solution; the pectin is selected from at least one of inorganic acid, organic acid, and strongly acidic anionic aluminum salt.
7. The preparation method according to claim 2, characterized in that, In method (1) or method (2), the roasting process is: roasting at 400-500℃ for 2-8 hours.
8. The preparation method according to claim 2, characterized in that, In step S2, the impregnation process is as follows: the alumina carrier is placed in the impregnation solution and impregnated for 20-60 minutes at 35-45°C under rotation.
9. The preparation method according to claim 2, characterized in that, In step S2, the roasting process is as follows: roasting at 400-500℃ for 3-8 hours.
10. A process for the preparation of a polyetheramine, characterized in that, Polyetheramines are synthesized using a supported nickel-based catalyst prepared by any one of claims 1-9.