Supported nickel catalyst for 3-hydroxypropanal fixed bed hydrogenation to 1,3-propanediol, its preparation method and application

Abstract

This invention discloses a supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanol to 1,3-propanediol, its preparation method, and its application, relating to the field of catalyst technology. The catalyst of this invention uses a support with a large specific surface area and large pore size as the matrix. The active component, nickel, is highly dispersed and uniformly loaded onto the support surface using a precipitation-deposition method. A neutral or basic binder is selected during the catalyst forming stage, avoiding the pre-calcination step of the precipitated product. This results in a catalyst with both high hydrogenation activity and a certain cost advantage. The supported nickel catalyst prepared by this invention exhibits high catalytic activity and selectivity in the fixed-bed hydrogenation of 3-hydroxypropanol to 1,3-propanediol, and is suitable for the industrial continuous production of 1,3-propanediol.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropionaldehyde to 1,3-propanediol, its preparation method, and its application. Background Technology

[0002] 1,3-Propanediol, abbreviated as 1,3-PDO, with the chemical formula C3H8O2, is a colorless, transparent, viscous liquid at room temperature. This substance is mainly used in the synthesis of polypropylene terephthalate (PTT), pharmaceutical intermediates, and antioxidants. In cosmetics, it is used as a moisturizer and solvent.

[0003] Currently, the main industrial routes for producing 1,3-PDO are biological and chemical methods. The chemical method has the advantages of mature processes and suitability for large-scale chemical production. Chemical methods include the production of 1,3-PDO from acrolein and from ethylene oxide. Both methods involve the hydration of acrolein and the carbonylation of ethylene oxide, respectively, to obtain the intermediate 3-hydroxypropanal (3-HPA). Then, 3-HPA is hydrogenated to obtain 1,3-PDO. Therefore, developing high-performance hydrogenation catalysts has become an important research direction in 1,3-PDO production. Catalysts used for the selective hydrogenation of 3-HPA to 1,3-PDO are generally classified into Raney-type metal catalysts, supported noble metal catalysts, and supported nickel catalysts.

[0004] Chinese invention patent CN1122568C discloses a catalyst for the hydrogenation of 3-hydroxypropanal to 1,3-propanediol, and Chinese invention patent CN112264044B discloses a Raney copper catalyst, its preparation method, and its application. Both patents provide highly active small-particle Raney catalysts and their application in a batch reactor for the hydrogenation of 3-HPA to 1,3-PDO. However, batch reactors require continuous catalyst replenishment to maintain activity, and the product needs to be filtered and separated from the catalyst, leading to complex operation and increased costs. Chinese invention patent CN114377685B discloses a nickel-based catalyst, its preparation method, and its application in the hydrogenation synthesis of 1,3-butanediol. Chinese invention patent CN102744083B discloses the preparation and activation method of a dedicated Raney nickel-aluminum-X catalyst for the hydrogenation of 1,4-butynediol to 1,4-butanediol. Both patents provide bulk Raney-type nickel catalysts suitable for fixed-bed hydrogenation reactions. However, the unactivated nickel-aluminum alloy inside this type of catalyst only serves as structural support for the catalyst itself, resulting in low utilization of the active components.

[0005] Chinese invention patent CN112457158B discloses a catalyst for the hydrogenation of 3-hydroxypropanal and its preparation method; CN105709778A discloses a catalyst for the catalytic hydrogenation of 3-hydroxypropanal to 1,3-propanediol, its preparation method, and its application; Chinese invention patent CN118416883A discloses a method for preparing a mesoporous α-Al2O3 supported Pd nanocatalyst and its catalytic hydrogenation of 3-hydroxypropanal; Chinese invention patent CN112264038B discloses a noble metal supported eggshell catalyst, its preparation method, and its application; Chinese invention patent CN119075982B discloses a platinum-based catalyst, its preparation method, and its application; and Chinese invention patent CN115141083A discloses a method for the hydrogenation of 3-hydroxypropanal to 1,3-propanediol. The aforementioned patents all provide methods for preparing supported noble metal catalysts. By introducing noble metal elements as active components and uniformly loading them onto porous oxide supports, high hydrogenation activity and selectivity are obtained in the 3-HPA to 1,3-PDO reaction. However, noble metals are expensive, and this type of catalyst does not have a cost advantage.

[0006] Chinese invention patent CN112457158B discloses a catalyst for the hydrogenation of 3-hydroxypropanal and its preparation method; Chinese invention patent CN1184181C discloses a method for the hydrogenation of 3-hydroxypropanal to 1,3-propanediol; and Chinese invention patent CN1319920C discloses a method for the hydrogenation of 3-hydroxypropanal to 1,3-propanediol. All of these patents provide supported nickel catalysts prepared using an equal-volume impregnation method, and improve their performance in the hydrogenation reaction by introducing multiple active components. The equal-volume impregnation method allows for uniform loading of active components onto the support surface, but the single loading amount is low. Multiple loading requires multiple calcinations, resulting in a cumbersome preparation process and increased production costs.

[0007] In summary, existing hydrogenation catalysts have limitations in terms of overall performance and cost control, which restricts the economic viability of 1,3-PDO production via 3-HPA fixed-bed hydrogenation. Therefore, developing a new generation catalyst that combines high activity and low cost is of great significance for improving the techno-economic competitiveness of this process. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a supported nickel catalyst for the hydrogenation of 3-hydroxypropanal to 1,3-propanediol in a fixed bed, as well as its preparation method and application. The catalyst has uniformly dispersed active components, high hydrogenation activity, and low production cost. At the same time, it has good hydrogenation effect in the hydrogenation of 3-HPA to 1,3-PDO in a fixed bed.

[0009] The technical solution of this invention is as follows:

[0010] In a first aspect, the present invention provides a method for preparing a supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol, comprising the following steps:

[0011] S1 prepares an aqueous solution of a nickel-soluble salt, adds an electronic additive, a structural additive, and a dispersant, and adjusts the pH of the solution to 1-3 to form a precursor solution; wherein the electronic additive is a nitrate or chloride of Co, Cu, or Zn, and the structural additive is a nitrate or chloride of Mg, La, or Ce; the concentration of nickel in the precursor solution is 0.5-2 mol / L, and the concentrations of the electronic additive and the structural additive are both 0.05-0.2 mol / L;

[0012] S2 involves adding the support to the precursor solution and stirring to form a slurry; the support is silica, alumina, or molecular sieve, with a specific surface area of ​​200-700 m². 2 / g, with an average pore size of 8-15nm;

[0013] S3 adds the composite precipitant to the slurry, and under stirring conditions, first heats it to 70-80℃ and maintains it for 1-3 hours, then continues to heat it to 80-95℃ and maintains it for 1-3 hours to carry out the precipitation reaction. After the heating is completed, it is left to stand and age. After cooling, it is filtered and washed until the filter cake is neutral. The composite precipitant includes a main precipitant and a secondary precipitant. The main precipitant is urea, and the secondary precipitant is ethanolamine, diethanolamine, or triethanolamine. The ratio of the number of moles of the main precipitant to the total number of moles of all metal elements is (1-4):1, and the molar ratio of the main precipitant to the secondary precipitant is 1:(0.05-0.5).

[0014] S4 places the filter cake, binder, and excipient in a kneader, and transfers the resulting kneaded mixture to an extruder to form a molded product; the binder is neutral silica sol, alkaline silica sol, or water glass;

[0015] S5 is dried and calcined to remove free water and excipients, resulting in a supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropionaldehyde to 1,3-propanediol.

[0016] Preferably, in step S1, the soluble salt of nickel is nickel nitrate.

[0017] Preferably, in step S1, the dispersant is PEG, and the molar ratio of the dispersant to all metal elements is (0.01-0.03):1; the pH of the solution is adjusted by a pH adjuster, which is nitric acid, hydrochloric acid, sulfuric acid or acetic acid.

[0018] Preferably, in step S2, the mass ratio of the active component nickel element in the catalyst to the support is (0.1-0.6):1.

[0019] Preferably, in step S3, the heating rate is 0.2-2℃ / min; and the static aging time is 2-6h.

[0020] Preferably, in step S4, the solid content of the binder is 20-40%, and the mass ratio of the binder to the filter cake is (0.1-0.3):1; the excipient is guar gum powder, and the mass ratio of the excipient to the filter cake is (0.01-0.1):1.

[0021] Preferably, in step S5, the drying temperature is 70-120℃ and the drying time is 4-24h; the calcination temperature is 300-600℃ and the calcination time is 2-12h.

[0022] Secondly, the present invention provides a supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanol to 1,3-propanediol, which is prepared by the above-described method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanol to 1,3-propanediol.

[0023] Thirdly, the present invention provides the application of the above-mentioned supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol. The supported nickel catalyst is loaded into a fixed-bed hydrogenation reactor, heated to 200-400°C under a hydrogen atmosphere, and reduced for 4-12 hours to activate the supported nickel catalyst. The bed temperature of the fixed-bed hydrogenation reactor is then reduced to 50-70°C, and the 3-hydroxypropanal solution is mixed with hydrogen and fed into the reactor at a reaction pressure of 3-6 MPa to obtain a 1,3-propanediol solution.

[0024] Preferably, the concentration of the 3-hydroxypropanal solution is 8-15 wt.%, and the solution space velocity is 0.5-3 h⁻¹. -1 The hydrogen space velocity is 100-500 h⁻¹ -1 .

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. This invention improves the hydrogenation reactivity and selectivity of nickel active centers by introducing electronic additives into the metal precursor solution, thereby adjusting the electron cloud density. The introduction of structural additives creates a spatial isolation effect on the catalyst surface, inhibiting the migration and aggregation of metal particles during calcination and reaction, thus improving the catalyst's thermal stability and lifespan. Simultaneously, the dispersant regulates the local concentration distribution of metal ions during precipitation, inhibiting rapid crystal nucleus aggregation and promoting uniform nucleation and dispersion of metal species on the support surface, which is beneficial for forming a smaller, more uniformly distributed active phase structure.

[0027] 2. In this invention, urea is used as the primary precipitant during the precipitation process. Its slow decomposition upon heating allows for a gradual increase in the system's pH, which facilitates the uniform deposition of metal components on the support surface. Simultaneously, the introduction of an auxiliary precipitant and the use of a staged heating method effectively control the rate and uniformity of the precipitation process, preventing localized enrichment of metal species. Combined with a support possessing a large pore size and specific surface area, the distribution of metal components inside and outside the support can be significantly improved, enhancing the catalyst's activity and stability.

[0028] 3. In the catalyst forming stage, the present invention uses a neutral or alkaline binder, which eliminates the need for pre-calcination of the precipitated product. On the one hand, this saves the extra calcination process, simplifies the production process and reduces costs. On the other hand, unlike acidic binders such as alumina sol and boehmite, it does not cause acidic erosion and structural damage to the freshly deposited active component precipitate that has not yet been thermally fixed. It can preserve the original morphology and active sites of the active components to the maximum extent, ensuring good catalytic performance of the catalyst. Attached Figure Description

[0029] Figure 1 This is an EDS surface scan image of the catalyst prepared in Example 1 of this invention. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention.

[0031] Example 1

[0032] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol in this embodiment includes the following steps:

[0033] S1 Weigh 1168g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 117g of cobalt nitrate hexahydrate, 173g of lanthanum nitrate hexahydrate and 36g of PEG600, and add nitric acid to adjust the pH of the solution to 2 to obtain the precursor solution;

[0034] S2 weighs 600g of macroporous silica powder (specific surface area 468m²). 2 (g, average pore size 12nm) was added to the above precursor solution and stirred until homogeneous to form a slurry;

[0035] S3 Weigh 720g of urea and 126g of diethanolamine and add them to the above slurry. Stir thoroughly and heat to 75℃ at a rate of 1℃ / min and maintain for 2h. Then continue to heat to 95℃ and maintain for 2h to carry out precipitation reaction. After the heating is completed, stop stirring and let it stand for 6h to age. After cooling, filter and wash until the filter cake is neutral.

[0036] S4. 1000g of filter cake, 30g of guar gum powder, and 300g of neutral silica sol with a solid content of 30% are placed in a kneader and kneaded thoroughly. The kneaded mixture is then transferred to an extruder to form the molded product.

[0037] S5 dried the molded product at 80°C for 4 hours and then calcined it at 500°C for 3 hours to obtain the supported nickel catalyst.

[0038] Depend on Figure 1 As shown in the EDS surface scan image of the supported nickel catalyst prepared in this embodiment, the characteristic signal of nickel element is continuously and dispersedly distributed throughout the selected area, and no micron- or submicron-level enrichment is observed, thus achieving uniform anchoring of the active component at the microscale.

[0039] Example 2

[0040] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol in this embodiment includes the following steps:

[0041] S1 Weigh 438g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 26g of copper chloride dihydrate, 260g of cerium nitrate hexahydrate and 40.5g of PEG600, and add nitric acid to adjust the pH of the solution to 1 to obtain the precursor solution;

[0042] S2 weighs 600g of macroporous silica powder (specific surface area 468m²). 2 (g, average pore size 12nm) was added to the above precursor solution and stirred until homogeneous to form a slurry;

[0043] S3 Weigh 270g of urea and 137g of ethanolamine and add them to the above slurry. Stir thoroughly and heat to 75℃ at a rate of 1℃ / min and maintain for 2h. Then continue to heat to 95℃ and maintain for 2h to carry out the precipitation reaction. After the heating is completed, stop stirring and let it stand for 6h to age. After cooling, filter and wash until the filter cake is neutral.

[0044] S4. 1000g of filter cake, 30g of guar gum powder, and 300g of water glass with a solid content of 30% are placed in a kneader and kneaded thoroughly. The kneaded mixture is then transferred to an extruder to form the molded product.

[0045] S5 dried the molded product at 80°C for 4 hours and then calcined it at 500°C for 3 hours to obtain the supported nickel catalyst.

[0046] Example 3

[0047] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol in this embodiment includes the following steps:

[0048] S1 Weigh 1752g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 179g of zinc nitrate hexahydrate, 31g of magnesium chloride hexahydrate, and 54g of PEG600, and add nitric acid to adjust the pH of the solution to 3 to obtain the precursor solution;

[0049] S2 weighs 600g of macroporous silica powder (specific surface area 468m²). 2 (g, average pore size 12nm) was added to the above precursor solution and stirred until homogeneous to form a slurry;

[0050] S3 Weigh 1080g of urea and 268g of triethanolamine and add them to the above slurry. Stir thoroughly and heat to 75℃ at a rate of 1℃ / min and maintain for 2h. Then continue to heat to 95℃ and maintain for 2h to carry out precipitation reaction. After the heating is completed, stop stirring and let it stand for 6h for aging. After cooling, filter and wash until the filter cake is neutral.

[0051] S4. 1000g of filter cake, 30g of guar gum powder, and 300g of neutral silica sol with a solid content of 30% are placed in a kneader and kneaded thoroughly. The kneaded mixture is then transferred to an extruder to form the molded product.

[0052] S5 dried the molded product at 80°C for 4 hours and then calcined it at 500°C for 3 hours to obtain the supported nickel catalyst.

[0053] Example 4

[0054] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol in this embodiment includes the following steps:

[0055] S1 Weigh 584g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 117g of cobalt nitrate hexahydrate, 173g of lanthanum nitrate hexahydrate and 36g of PEG600, and add nitric acid to adjust the pH of the solution to 2 to obtain the precursor solution;

[0056] S2 weighs 600g of alumina powder (specific surface area 227m²). 2 (g, average pore size 15nm) was added to the above precursor solution and stirred until homogeneous to form a slurry;

[0057] S3 Weigh 360g of urea and 63g of diethanolamine and add them to the above slurry. Stir thoroughly and heat to 75℃ at a rate of 1℃ / min and maintain for 2h. Then continue to heat to 95℃ and maintain for 2h to carry out the precipitation reaction. After the heating is completed, stop stirring and let it stand for 6h to age. After cooling, filter and wash until the filter cake is neutral.

[0058] S4. 1000g of filter cake, 30g of guar gum powder, and 300g of neutral silica sol with a solid content of 30% are placed in a kneader and kneaded thoroughly. The kneaded mixture is then transferred to an extruder to form the molded product.

[0059] S5 dried the molded product at 80°C for 4 hours and then calcined it at 500°C for 3 hours to obtain the supported nickel catalyst.

[0060] Example 5

[0061] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol in this embodiment includes the following steps:

[0062] S1 Weigh 1571g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 87g of cobalt nitrate hexahydrate, 130g of lanthanum nitrate hexahydrate and 36g of PEG600, and add hydrochloric acid to adjust the pH of the solution to 2 to obtain the precursor solution;

[0063] S2 weighs 600g of SBA-15 molecular sieve powder (specific surface area 649m²). 2 (g, average pore size 8nm) was added to the above precursor solution and stirred until homogeneous to form a slurry;

[0064] S3 Weigh 1080g of urea and 189g of diethanolamine and add them to the above slurry. Stir thoroughly and heat to 75℃ at a rate of 1℃ / min and maintain for 2h. Then continue to heat to 95℃ and maintain for 2h to carry out precipitation reaction. After the heating is completed, stop stirring and let it stand for 6h for aging. After cooling, filter and wash until the filter cake is neutral.

[0065] S4. 1000g of filter cake, 30g of guar gum powder, and 400g of neutral silica sol with a solid content of 20% are placed in a kneader and kneaded thoroughly. The kneaded mixture is then transferred to an extruder to form the molded product.

[0066] S5 dried the molded product at 80°C for 4 hours and then calcined it at 500°C for 3 hours to obtain the supported nickel catalyst.

[0067] Example 6

[0068] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol in this embodiment includes the following steps:

[0069] S1 Weigh 657g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 113g of cobalt nitrate hexahydrate, 156g of lanthanum nitrate hexahydrate and 36g of PEG600, and add sulfuric acid to adjust the pH of the solution to 2 to obtain the precursor solution;

[0070] S2 weighs 600g of macroporous silica powder (specific surface area 468m²). 2 (g, average pore size 12nm) was added to the above precursor solution and stirred until homogeneous to form a slurry;

[0071] S3 Weigh 720g of urea and 63g of diethanolamine and add them to the above slurry. Stir thoroughly and heat to 75℃ at a rate of 1℃ / min and maintain for 2h. Then continue to heat to 95℃ and maintain for 1h to carry out the precipitation reaction. After the heating is completed, stop stirring and let it stand for 6h to age. After cooling, filter and wash until the filter cake is neutral.

[0072] S4. 1000g of filter cake, 30g of guar gum powder, and 400g of neutral silica sol with a solid content of 20% are placed in a kneader and kneaded thoroughly. The kneaded mixture is then transferred to an extruder to form the molded product.

[0073] S5 dried the molded product at 80°C for 4 hours and then calcined it at 500°C for 3 hours to obtain the supported nickel catalyst.

[0074] Example 7

[0075] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol in this embodiment includes the following steps:

[0076] S1 Weigh 1168g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 118g of copper nitrate hexahydrate, 173g of cerium nitrate hexahydrate and 36g of PEG600, and add acetic acid to adjust the pH of the solution to 2 to obtain the precursor solution;

[0077] S2 weighs 600g of macroporous silica powder (specific surface area 468m²). 2 (g, average pore size 12nm) was added to the above precursor solution and stirred until homogeneous to form a slurry;

[0078] S3 Weigh 540g of urea and 473g of diethanolamine and add them to the above slurry. Stir thoroughly and heat to 70℃ at a rate of 0.2℃ / min and maintain for 3h. Then continue to heat to 80℃ and maintain for 3h to carry out precipitation reaction. After the heating is completed, stop stirring and let it stand for 5h for aging. After cooling, filter and wash until the filter cake is neutral.

[0079] S4. 1000g of filter cake, 100g of guar gum powder, and 200g of alkaline silica sol with a solid content of 30% are placed in a kneader and kneaded thoroughly. The kneaded mixture is then transferred to an extruder to form a molded product.

[0080] S5 dried the molded product at 70°C for 24 hours and then calcined it at 600°C for 2 hours to obtain the supported nickel catalyst.

[0081] Example 8

[0082] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol in this embodiment includes the following steps:

[0083] S1 Weigh 1168g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 117g of cobalt nitrate hexahydrate, 173g of lanthanum nitrate hexahydrate and 36g of PEG600, and add nitric acid to adjust the pH of the solution to 2 to obtain the precursor solution;

[0084] S2 weighs 600g of macroporous silica powder (specific surface area 468m²). 2 (g, average pore size 12nm) was added to the above precursor solution and stirred until homogeneous to form a slurry;

[0085] S3 Weigh 960g of urea and 168g of diethanolamine and add them to the above slurry. Stir thoroughly and heat to 80℃ at a rate of 2℃ / min and maintain for 1h. Then continue to heat to 90℃ and maintain for 3h to carry out precipitation reaction. After the heating is completed, stop stirring and let it stand for 6h for aging. After cooling, filter and wash until the filter cake is neutral.

[0086] S4. 1000g of filter cake, 10g of guar gum powder, and 200g of alkaline silica sol with a solid content of 40% are placed in a kneader and kneaded thoroughly. The kneaded mixture is then transferred to an extruder to form a molded product.

[0087] S5 dried the molded product at 120℃ for 10h and then calcined it at 300℃ for 12h to obtain the supported nickel catalyst.

[0088] Comparative Example 1

[0089] The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanol in Comparative Example 1 includes the following steps:

[0090] S1 Weigh 1168g of nickel nitrate hexahydrate, add it to 3000mL of deionized water to dissolve it, add 117g of cobalt nitrate hexahydrate and 173g of lanthanum nitrate hexahydrate to obtain the precursor solution;

[0091] S2 uses a precursor solution to treat 600g of silica powder (specific surface area 468m²). 2 The sample was impregnated twice with equal volume (g, average pore size 12nm). After each impregnation, the sample was left to stand for 6 hours, then dried at 80℃ for 4 hours, and then calcined at 500℃ for 3 hours.

[0092] S3. The product obtained in step S2 is mixed thoroughly with 100g of deionized water, 30g of guar gum powder and 300g of neutral silica sol with a solid content of 30% in a kneader. The kneaded mixture is then transferred to an extruder to form the molded product.

[0093] S4 dried the molded product at 80°C for 4 hours and then calcined it at 500°C for 3 hours to obtain the supported nickel catalyst.

[0094] Comparative Example 2

[0095] The difference from Example 1 is that, in step S2, industrial silica powder (specific surface area 142 m²) is used. 2 (g, average pore size 5nm) to replace macroporous silica powder.

[0096] Comparative Example 3

[0097] The difference from Example 1 is that in step S3, 318g of sodium carbonate is used instead of 720g of urea and 126g of diethanolamine.

[0098] Comparative Example 4

[0099] The difference from Example 1 is that in step S4: 154g of boehmite, 34g of 37wt.% hydrochloric acid, and 145mL of deionized water are mixed and stirred for 1 hour to prepare an acidified boehmite slurry; 1000g of the filter cake obtained in step S3 is placed in a kneader with 30g of guar gum powder and the above acidified boehmite slurry and kneaded thoroughly, and the kneaded mixture is transferred to an extruder to form a molded product.

[0100] Comparative Example 5

[0101] The difference from Example 1 is that in step S1, 117g of cobalt nitrate hexahydrate and 173g of lanthanum nitrate hexahydrate are not added.

[0102] Comparative Example 6

[0103] The difference from Example 1 is that in step S3, the temperature is directly increased to 95°C at a rate of 1°C / min and maintained for 4 hours to carry out the precipitation reaction.

[0104] Comparative Example 7

[0105] The difference from Example 1 is that diethanolamine is not added in step S3.

[0106] The supported nickel catalysts obtained in Examples 1-8 and Comparative Examples 1-7 were used in the fixed-bed hydrogenation reaction of 3-hydroxypropanal to 1,3-propanediol: The supported nickel catalysts were loaded into a fixed-bed hydrogenation reactor, and the temperature was raised to 300°C under a hydrogen atmosphere with an H2 space velocity of 200 h⁻¹. -1 The reactor was reduced for 8 hours to activate it; after activation, feeding began, and the bed temperature of the fixed-bed hydrogenation reactor was lowered to 65°C. The feedstock was a 10 wt.% 3-hydroxypropanal solution with a space velocity of 1.2 h⁻¹. -1 The hydrogen space velocity is 300 h⁻¹. -1The reaction pressure is 4 MPa.

[0107] The reaction products were analyzed by gas chromatography, and the conversion rate of 3-hydroxypropionaldehyde and the selectivity of 1,3-propanediol were calculated. The results are shown in Table 1.

[0108] Table 1. 3-Hydroxypropanal conversion and 1,3-propanediol selectivity of supported nickel catalysts in Examples 1-8 and Comparative Examples 1-7

[0109]

[0110] As shown in Table 1, compared with Comparative Examples 1-7, the supported nickel catalysts in Examples 1-8 all exhibited higher conversion rates and selectivity. Comparative Example 1 used an impregnation method to prepare the catalyst. The precursor solution mainly entered the support pores through capillary adsorption, lacking in-situ nucleation control during the precipitation process. Metal salts were prone to migration and aggregation during drying and calcination, leading to enrichment of active components on the outer surface of the support and the formation of larger particles. Therefore, the catalyst obtained in Comparative Example 1 had low metal dispersion and a reduced number of effective active sites, resulting in decreased hydrogenation performance. Comparative Example 2 did not use a large-pore, high-specific-surface-area support. Ordinary low-specific-surface-area supports had small pore volumes and uniform pore size distribution, limiting the diffusion and deposition space of metal ions during precipitation, leading to reduced utilization of active sites. Therefore, the catalyst in Comparative Example 2 exhibited lower reactivity and stability. Comparative Example 3 used a strongly alkaline precipitant and did not employ a composite precipitation system. The addition of sodium carbonate caused a rapid increase in the pH of the system within a short time, resulting in local supersaturation and instantaneous precipitation of metal ions, forming free precipitates or aggregated structures. Due to the lack of slow hydrolysis by urea and the synergistic regulation of auxiliary precipitants, uniform nucleation is difficult to achieve during precipitation, leading to reduced metal dispersion and decreased catalytic performance. Comparative Example 4 uses acidified pseudoboehmite slurry as a binder, which introduces acidic substances during the molding process. This may cause localized dissolution and redistribution of the deposited metal precursor, affecting the uniformity of the active components. Simultaneously, acidic conditions may alter the surface properties of the support, hindering the stable existence of metal particles and thus reducing catalyst activity. Comparative Example 5 lacks electronic and structural additives, resulting in a lack of structural regulation of the nickel active component. During calcination and reduction, particle migration and agglomeration are more likely to occur, leading to increased metal particle size. Furthermore, the lack of electronic and structural additives to regulate the electronic environment of the active centers reduces the catalyst's activity and stability. Comparative Example 6 did not employ a staged heating process during deposition. Directly heating to a high temperature rapidly increases the precipitation reaction rate, causing nucleation and growth to occur simultaneously within a short period, easily leading to the formation of large precipitate particles. The lack of a uniform nucleation process at low temperatures makes it difficult for metal species to distribute evenly on the inner and outer surfaces of the support, ultimately affecting metal dispersion and catalytic performance. Comparative Example 7 lacks composite precipitation control. Without the addition of an auxiliary precipitant, the precipitation rate of metal ions in the system is mainly determined by urea decomposition, resulting in a relatively simple precipitation control method. Compared to the composite precipitation system, the controllability of the precipitation process is reduced, and the uniformity of metal species distribution decreases, thus affecting the catalyst's activity.

[0111] In summary, this invention achieves effective control over the metal deposition process through a combination of techniques such as additive regulation, composite precipitant, staged heating, carrier structure optimization, and molding process optimization. This results in higher dispersion and stability of the active components, significantly improving catalyst performance.

Claims

1. A method for preparing a supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol, characterized in that, Includes the following steps: S1 prepares an aqueous solution of a nickel-soluble salt, adds an electronic additive, a structural additive, and a dispersant, and adjusts the pH of the solution to 1-3 to form a precursor solution; wherein the electronic additive is a nitrate or chloride of Co, Cu, or Zn, and the structural additive is a nitrate or chloride of Mg, La, or Ce; the concentration of nickel in the precursor solution is 0.5-2 mol / L, and the concentrations of the electronic additive and the structural additive are both 0.05-0.2 mol / L; S2 involves adding the support to the precursor solution and stirring to form a slurry; the support is silica, alumina, or molecular sieve, with a specific surface area of ​​200-700 m². 2 / g, with an average pore size of 8-15nm; S3 adds the composite precipitant to the slurry, and under stirring conditions, first heats it to 70-80℃ and maintains it for 1-3 hours, then continues to heat it to 80-95℃ and maintains it for 1-3 hours to carry out the precipitation reaction. After the heating is completed, it is left to stand and age. After cooling, it is filtered and washed until the filter cake is neutral. The composite precipitant includes a main precipitant and a secondary precipitant. The main precipitant is urea, and the secondary precipitant is ethanolamine, diethanolamine, or triethanolamine. The ratio of the number of moles of the main precipitant to the total number of moles of all metal elements is (1-4):1, and the molar ratio of the main precipitant to the secondary precipitant is 1:(0.05-0.5). S4 places the filter cake, binder, and excipient in a kneader, and transfers the resulting kneaded mixture to an extruder to form a molded product; the binder is neutral silica sol, alkaline silica sol, or water glass; S5 is dried and calcined to remove free water and excipients, resulting in a supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropionaldehyde to 1,3-propanediol.

2. The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol as described in claim 1, characterized in that, In step S1, the soluble salt of nickel is nickel nitrate.

3. The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol as described in claim 1, characterized in that, In step S1, the dispersant is PEG, and the molar ratio of the dispersant to all metal elements is (0.01-0.03):1; the pH of the solution is adjusted by a pH adjuster, which is nitric acid, hydrochloric acid, sulfuric acid or acetic acid.

4. The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol as described in claim 1, characterized in that, In step S2, the mass ratio of the active component nickel element in the catalyst to the support is (0.1-0.6):

1.

5. The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol as described in claim 1, characterized in that, In step S3, the heating rate is 0.2-2℃ / min; the static aging time is 2-6h.

6. The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol as described in claim 1, characterized in that, In step S4, the solid content of the binder is 20-40%, and the mass ratio of the binder to the filter cake is (0.1-0.3):1; the excipient is guar gum powder, and the mass ratio of the excipient to the filter cake is (0.01-0.1):

1.

7. The method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol as described in claim 1, characterized in that, In step S5, the drying temperature is 70-120℃ and the drying time is 4-24h; the calcination temperature is 300-600℃ and the calcination time is 2-12h.

8. A supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol, characterized in that, It was prepared by the method for preparing the supported nickel catalyst for the fixed-bed hydrogenation of 3-hydroxypropionaldehyde to 1,3-propanediol as described in any one of claims 1-7.

9. The application of the supported nickel catalyst as described in claim 8 for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol, characterized in that, A supported nickel catalyst is loaded into a fixed-bed hydrogenation reactor and heated to 200-400℃ under a hydrogen atmosphere for 4-12 hours to activate the supported nickel catalyst. The bed temperature of the fixed-bed hydrogenation reactor is then reduced to 50-70℃, and a 3-hydroxypropanal solution is mixed with hydrogen and fed into the reactor at a reaction pressure of 3-6 MPa to obtain a 1,3-propanediol solution.

10. The application of the supported nickel catalyst as described in claim 9 for the fixed-bed hydrogenation of 3-hydroxypropanal to 1,3-propanediol, characterized in that, The concentration of the 3-hydroxypropanal solution was 8-15 wt.%, and the solution space velocity was 0.5-3 h⁻¹. -1 The hydrogen space velocity is 100-500 h⁻¹ -1 .

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