A supported nickel-based molding catalyst, its preparation method, and its application in hydrogenation reactions.

Abstract

This invention discloses a supported nickel-based molding catalyst, its preparation method, and its application. The preparation method of the supported nickel-based molding catalyst includes the following steps: obtaining a SiO2 support; preparing a mixed aqueous solution of nickel salt, polyethylene glycol, and a nitrogen-containing organic compound; adding the SiO2 support, stirring, and evaporating to obtain a paste-like precursor; calcining the paste-like precursor at high temperature to obtain a supported nickel-based catalyst powder; obtaining a kneading liquid; taking the supported nickel-based catalyst powder, binder, and kneading liquid, extruding and mixing to obtain a wet gel; extruding the wet gel into wet strips, drying to obtain a green body; and calcining the green body at high temperature to obtain the supported nickel-based molding catalyst. This invention provides the application of the supported nickel-based molding catalyst in the catalytic hydrogenation reaction of p-chloronitrobenzene. The nickel-based molding catalyst obtained by this invention has the advantages of not requiring a high-temperature hydrogen reduction pretreatment step, high mechanical strength, and a simple preparation method.

Description

Technical Field

[0001] This invention relates to a supported nickel-based molding catalyst and its preparation method, and its application in p-chloronitrobenzene (… p Applications of CNB in ​​hydrogenation reactions. Background Technology

[0002] Ni is a relatively abundant element in the Earth's crust, and its cost is lower than that of precious metals such as palladium and platinum. Therefore, nickel-based catalysts have higher economic applicability and are widely used in organic synthesis and industrial hydrogenation reactions, especially in the hydrogenation of unsaturated compounds (such as alkenes, alkynes, dienes, etc.). In addition to hydrogenation reactions, nickel-based catalysts can also be used in dehydrogenation and other reaction processes [R. Paul, et al. Asian Journal of Organic Chemistry, 2025, 14(8), e00069.]. Supported nickel-based catalysts are usually prepared by impregnation or precipitation methods, so high-temperature activation pretreatment in flowing hydrogen is required before the catalytic reaction to convert the NiO precursor into metallic Ni active centers [Yang L, et al. AppliedCatalysis A: General, 2026, 712: 120772.]. At the same time, although powdered supported nickel-based catalysts have good catalytic activity, due to their powder characteristics, they have inherent defects such as large pressure drop, poor mass and heat transfer, and low mechanical strength during the reaction process, and cannot be directly used in industrial fixed-bed reactors.

[0003] Therefore, catalyst particle forming is extremely important for the industrial application of catalysts. Industrial catalyst particle forming involves using specific forming methods to shape powdered catalysts into particles with specific structures and shapes. For supported nickel-based catalysts, the formed catalyst not only needs high strength, suitable pore structure, particle shape and size, but also needs to possess metallic Ni active centers. However, using existing forming techniques, after obtaining the formed catalyst particles, a high-temperature pretreatment in a hydrogen atmosphere is still required to convert the NiO precursor into metallic Ni active centers [Cai Zhi et al., Chinese Patent CN 102527390 B]. This not only increases the operational steps and safety hazards in practical applications, but also the phase transformation during the reduction process can affect the properties of the formed catalyst (e.g., mechanical strength). Therefore, developing a supported nickel-based catalyst preparation and forming technology that does not require high-temperature hydrogen reduction pretreatment is of great significance and economic value for expanding the industrial application of nickel-based catalysts. Summary of the Invention

[0004] To address the problems and shortcomings in the preparation of nickel-based molding catalysts mentioned above, the purpose of this invention is to provide a new supported nickel-based molding catalyst, its preparation method, and its application in the catalytic hydrogenation reaction of p-chloronitrobenzene. The nickel-based molding catalyst obtained by this invention has the advantages of not requiring a high-temperature hydrogen reduction pretreatment step, high mechanical strength, and simple preparation method.

[0005] The technical solutions adopted to solve the above problems are described below.

[0006] In a first aspect, the present invention provides a method for preparing a supported nickel-based molding catalyst, the method comprising the following steps: (a) A surface area of ​​not less than 300 m² 2 / g of SiO2 powder was added to a nitric acid solution for treatment, and then the desired SiO2 support was obtained by filtration, washing, drying and high-temperature calcination. (b) Dissolve the nickel salt, polyethylene glycol, and nitrogen-containing organic compound in deionized water and n-butanol, and reflux the mixture in an oil bath at 100-120°C for 1-2 hours to obtain a mixed solution; the nickel salt is one of nickel nitrate hexahydrate, anhydrous nickel sulfate, nickel sulfate hexahydrate, nickel sulfate heptahydrate, and nickel chloride hexahydrate; the polyethylene glycol has a molecular weight of 1000-2000; the nitrogen-containing organic compound is one of melamine and urea; based on the total mass of the nickel salt, polyethylene glycol, and nitrogen-containing organic compound as 100%, the mass percentage of the nickel salt is 20-25%, the mass percentage of the polyethylene glycol is 45-50%, and the mass percentage of the nitrogen-containing organic compound is 25-30%. (c) Under stirring conditions, SiO2 support is added to the mixture obtained in step (b), and then evaporated to dryness to obtain a paste-like precursor, such that the theoretical nickel loading is 20-40 wt%, where the theoretical loading = m Ni ÷(m Ni +m SiO2载体 )×100%, where m Ni and m SiO2载体 These refer to the mass of nickel in the mixture and the mass of the SiO2 support, respectively. (d) The paste-like precursor obtained in step (c) is calcined at 500-600℃ for 4-5 hours under an inert atmosphere, and then cooled and ground to obtain a supported nickel-based catalyst powder. (e) Dissolve the adhesive solvent and the extrusion aid in deionized water to obtain a kneading solution; the adhesive solvent is a combination of citric acid and concentrated nitric acid; the extrusion aid is one or more of polyethylene glycol 400, guar gum powder, and starch; in the kneading solution, the mass percentages of the adhesive solvent and the extrusion aid are 1 wt%~5 wt% and 1 wt%~10 wt%, respectively. (f) Take the supported nickel-based catalyst powder obtained in step (d) and mix it with the binder. Add the kneading liquid dropwise to the mixture of supported nickel-based catalyst powder and binder in a certain proportion, and continuously squeeze and knead to ensure that the powder particles are fully and evenly mixed with the kneading liquid to obtain a wet gel. The binder is boehmite or a mixture of boehmite and montmorillonite. The mass ratio of the supported nickel-based catalyst powder to the binder is 1:0.4~0.5. The water-powder mass ratio of the kneading liquid to the mixture of catalyst powder and binder is 1.0~1.5. (g) Extrude the wet gel into uniform wet strips and dry them to obtain a green body; (h) The green body is placed in a tube furnace and calcined at 500 ~ 590 ℃ for 3 ~ 5 h under an inert atmosphere to obtain a supported nickel-based forming catalyst.

[0007] Further, in step (a), the concentration of the nitric acid solution is 1-3 mol / L, and the nitric acid treatment conditions are: stirring at room temperature for 2-4 hours. The oven drying conditions are: oven drying temperature of 100-120℃, more preferably 120℃; drying time of 5-6 hours, more preferably 6 hours; and high-temperature calcination treatment conditions are: the high-temperature calcination atmosphere is preferably air, the calcination temperature is 500-600℃, more preferably 600℃, and the calcination time is 6-8 hours, more preferably 8 hours.

[0008] Furthermore, the nickel salt mentioned in step (b) is preferably nickel nitrate hexahydrate, the polyethylene glycol is polyethylene glycol-1000, and the nitrogen-containing organic compound is preferably melamine.

[0009] Furthermore, the oil bath treatment conditions described in step (b) are: oil bath temperature of 120 ℃ and oil bath time of 2 h.

[0010] Furthermore, in step (c), the evaporation is carried out at 100~120°C.

[0011] Furthermore, in step (d), the inert atmosphere is a nitrogen atmosphere, and the high-temperature calcination conditions are: calcination temperature of 550 °C and calcination time of 4 h.

[0012] Furthermore, in step (d), the particle size range of the catalyst powder is preferably 140 to 160 mesh.

[0013] Furthermore, the extrusion aid mentioned in step (e) is preferably polyethylene glycol 400.

[0014] Furthermore, in step (e), the preferred mass ratio of concentrated nitric acid and citric acid in the adhesive solvent is 1:1 to 2.

[0015] Furthermore, in step (e), the kneading solution is prepared from concentrated nitric acid, citric acid, polyethylene glycol 400 and deionized water, wherein the mass ratio of concentrated nitric acid, citric acid, polyethylene glycol 400 and deionized water is 10.5:12.2:21:454.

[0016] Further, in step (f), the binder is preferably a mixture of boehmite and montmorillonite, more preferably a mixture of boehmite and montmorillonite in a mass ratio of 2:1. Even further, in step (f), the mass ratio of the supported nickel-based catalyst powder to the binder is 1:0.5, and the binder is a mixture of boehmite and montmorillonite in a mass ratio of 2:1.

[0017] Furthermore, the water-to-powder mass ratio of the kneading liquid to the mixture of catalyst powder and binder in step (f) is 1.1-1.3, more preferably 1.1.

[0018] Furthermore, in step (h), the inert atmosphere is a nitrogen atmosphere, and the high-temperature calcination conditions are: calcination temperature of 550 ℃ and calcination time of 4 h.

[0019] In a second aspect, the present invention provides a supported nickel-based molding catalyst prepared according to the preparation method described in the first aspect.

[0020] Thirdly, the present invention provides the application of the supported nickel-based molding catalyst described in the second aspect in the catalytic hydrogenation reaction of p-chloronitrobenzene.

[0021] The supported nickel-based shaped catalyst prepared by this invention has high radial particle strength and exhibits excellent reactivity and selectivity for p-chloroaniline products during the catalytic hydrogenation of p-chloronitrobenzene.

[0022] Compared with the prior art, the present invention has the following advantages: (1) The nickel-based molding catalyst of the present invention only requires simple impregnation, extrusion and calcination steps. The preparation process is simple and does not require complicated instruments and equipment.

[0023] (2) The nickel-based molding catalyst of the present invention does not use toxic and environmentally hazardous strong reducing agents or hydrogen reduction in its preparation process, making the preparation process green and environmentally friendly.

[0024] (3) The catalyst forming method used in this invention can not only enable the formed catalyst to obtain high radial particle strength (lateral pressure resistance ≥50 N / cm), but also enable the formed catalyst to maintain good catalytic reaction performance.

[0025] (4) The nickel-based molding catalyst reported in this invention has high strength and good catalytic performance in the catalytic hydrogenation of chloronitrobenzene, showing excellent reactivity and product selectivity. Attached Figure Description

[0026] Figure 1 The image shows the XRD pattern of the supported nickel-based catalyst powder prepared in Example 1.

[0027] Figure 2 This is the XRD pattern of the supported nickel-based molding catalyst prepared in Example 1.

[0028] Figure 3 The image shows the XRD pattern of the supported nickel-based molding catalyst prepared by Comparative Example 2.

[0029] Figure 4 The image shows the XRD pattern of the supported nickel-based molding catalyst prepared by Comparative Example 3.

[0030] Figure 5 This is the XRD pattern of the supported nickel-based molding catalyst prepared by Comparative Example 4. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited by the following embodiments.

[0032] Unless otherwise specified in the embodiments of this invention, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained through conventional technical means or commercially available.

[0033] In this embodiment of the invention, unless otherwise specified, the operating temperature is room temperature, approximately 25°C.

[0034] Example 1

[0035] SiO2 powder (Qingdao Baishahe Company) was placed in a nitric acid solution (1 mol L). -1 The mixture was stirred at room temperature for 3 hours, then washed with deionized water until the pH of the filtrate was neutral. It was then placed in an oven and dried thoroughly at 120 °C for 6 hours. Finally, the powder was placed in a muffle furnace and heated to 600 °C at a rate of 5 °C / min, and calcined at this temperature for 8 hours to obtain the desired SiO2 support (specific surface area = 337.0 m²). 2 / g, pore volume = 0.8 cm 3 / g, pore size = 9.9 nm).

[0036] 1.66 g Ni(NO3)2·6H2O, 3.5 g polyethylene glycol (PEG, average molecular weight = 1000), 2 g melamine, 30 cm 3 n-Butanol and 90 cm 3Deionized water was mixed under stirring and then refluxed at 120°C for 2 hours. 0.78 g of SiO2 powder was added under stirring. The solvent was then evaporated at 120°C until a paste-like sample was formed. The resulting precursor was placed in a tube furnace and calcined at 550°C for 4 hours in a flowing N2 atmosphere. After cooling, it was ground into 140-160 mesh powder to obtain the supported nickel-based catalyst powder. (Appendix) Figure 1 This is the XRD pattern of the catalyst powder. The broad diffraction peak at 2θ ≈ 20 - 25° corresponds to amorphous SiO2. The diffraction peaks at 2θ ≈ 44.5°, 51.8°, and 76.4° can be attributed to the (111), (200), and (220) crystal planes of metallic Ni, respectively. The Ni content in the catalyst was estimated using the Scherer equation. 0 The particle size is approximately 18.6 nm.

[0037] 10.5 g of 68% GR pure concentrated nitric acid solution, 12.2 g of GR pure citric acid solid, and 21.0 g of AR pure polyethylene glycol 400 were dissolved in 454.0 g of deionized water to obtain a kneading solution. Catalyst powder, SB powder, and montmorillonite were mixed in a ratio of catalyst:SB powder:montmorillonite = 6:2:1. The mixture was then added dropwise to the kneading solution at a water-to-powder mass ratio of 1.1, and kneaded into a ball to obtain a wet gel. The wet gel was extruded into uniformly sized wet strips and allowed to dry naturally at room temperature in a ventilated area for 6 h, followed by drying at 55°C for 12 h. The green body was placed in a tube furnace and calcined at 550°C for 4 h under a N2 atmosphere to obtain the supported nickel-based molding catalyst Ni@CN / SiO2-CX.

[0038] The XRD pattern of the supported nickel-based forming catalyst is attached. Figure 2 As shown. The broad diffraction peaks at 2θ ≈ 20 - 25° can correspond to amorphous SiO2. Furthermore, the diffraction peaks at 2θ ≈ 36° and 67.0° can be attributed to the γ-Al2O3 crystal phase formed after calcination of boehmite. The diffraction peaks at 2θ ≈ 44.5°, 51.9°, and 76.4° can be attributed to the (111), (200), and (220) crystal planes of metallic Ni, indicating that the metallic Ni crystal phase still exists in the nickel-based forming catalyst. The Ni content in the nickel-based forming catalyst was estimated using the Scherer equation. 0 The particle size is approximately ~17.1 nm. The above XRD characterization (see attached diagram) Figure 1 and 2This indicates that the method described in Example 1 can directly prepare supported Ni-based catalyst powder containing metallic Ni grains without high-temperature H2 pretreatment, and the forming method has little impact on the metallic Ni grains.

[0039] Comparative Example 1

[0040] SiO2 powder (Qingdao Baishahe Company) was placed in a nitric acid solution (1 mol L). -1 The mixture was stirred at room temperature for 3 hours, then washed with deionized water until the pH of the filtrate was neutral. It was then placed in an oven and dried thoroughly at 120 °C for 6 hours. Finally, the powder was placed in a muffle furnace and heated to 600 °C at a rate of 5 °C / min, and calcined at this temperature for 8 hours to obtain the desired SiO2 support (specific surface area = 337.0 m²). 2 / g, pore volume = 0.8 cm 3 / g, pore size = 9.9 nm).

[0041] 1.66 g Ni(NO3)2·6H2O, 3.5 g polyethylene glycol (PEG, average molecular weight = 1000), 2 g melamine, 30 cm 3 n-Butanol and 90 cm 3 Deionized water was mixed under stirring and then refluxed at 120°C for 2 h. 0.78 g of SiO2 powder was added under stirring. The solvent was then evaporated at 120°C until a paste-like sample was formed. The resulting precursor was placed in a tube furnace and calcined at 550°C for 4 h in a flowing N2 atmosphere. After cooling, it was ground into 140-160 mesh powder to obtain the supported nickel-based catalyst powder.

[0042] 10.5 g of 68% GR pure concentrated nitric acid solution, 12.2 g of GR pure citric acid solid, and 21.0 g of AR pure polyethylene glycol 400 were dissolved in 454.0 g of deionized water to obtain a kneading solution. Catalyst powder, SB powder, and montmorillonite were mixed in a ratio of catalyst:SB powder:montmorillonite = 10:2:1. The mixture was then added dropwise to the kneading solution at a water-to-powder mass ratio of 1.1 drops, kneading until a wet gel was obtained. The wet gel was extruded into uniform wet strips using a syringe (2 mm inner diameter) and allowed to dry naturally at room temperature in a ventilated area for 6 h, followed by drying at 55 °C for 12 h. The green body was placed in a tube furnace and calcined at 550 °C for 4 h under a N2 atmosphere to obtain the nickel-based molding catalyst Ni@CN / SiO2-CX-1.

[0043] Comparative Example 2

[0044] SiO2 powder (Qingdao Baishahe Company) was placed in a nitric acid solution (1 mol L). -1 The mixture was stirred at room temperature for 3 hours, then washed with deionized water until the pH of the filtrate was neutral. It was then placed in an oven and dried thoroughly at 120°C for 6 hours. Finally, the powder was placed in a muffle furnace and heated to 600°C at a rate of 5°C / min, and calcined at this temperature for 8 hours to obtain the desired SiO2 support (specific surface area = 337.0 m²). 2 / g, pore volume = 0.8 cm 3 / g, pore size = 9.9 nm).

[0045] 1.66 g Ni(NO3)2·6H2O, 3.5 g polyethylene glycol (PEG, average molecular weight = 1000), 2 g melamine, 30 cm 3 n-Butanol and 90 cm 3 Deionized water was mixed under stirring and then refluxed at 120°C for 2 h. 0.78 g of SiO2 powder was added under stirring. The solvent was then evaporated at 120°C until a paste-like sample was formed. The obtained precursor was placed in a tube furnace and calcined at 550°C for 4 h in a flowing N2 atmosphere. After cooling, it was ground into 140–160 mesh powder to obtain the supported nickel-based catalyst powder.

[0046] 10.5 g of 68% GR pure concentrated nitric acid solution, 12.2 g of GR pure citric acid solid, and 21.0 g of AR pure polyethylene glycol 400 were dissolved in 454.0 g of deionized water to obtain a kneading solution. Catalyst powder, SB powder, and montmorillonite were mixed in a ratio of catalyst:SB powder:montmorillonite = 10:2:1. The mixture was added dropwise to the kneading solution at a water-to-powder mass ratio of 1.1 drops, and kneaded into a ball to obtain a wet gel. The wet gel was extruded into uniform wet strips using a syringe (2 mm inner diameter) and allowed to dry naturally at room temperature in a ventilated area for 6 h, followed by drying at 55°C for 12 h. The green body was placed in a tube furnace and calcined at 550°C in air for 4 h to obtain the nickel-based molding catalyst Ni@CN / SiO2-CX-2.

[0047] The XRD pattern of the catalyst is attached. Figure 3As shown. The broad diffraction peak at 2θ ≈ 20 - 25° corresponds to amorphous SiO2. The diffraction peaks appearing at 2θ ≈ 37.2°, 43.2°, 62.8°, 75.3°, and 79.3° can be attributed to the NiO (111), (200), (220), (311), and (222) crystal planes, indicating that the Ni species exists entirely in the form of NiO. The particle size of NiO in the nickel-based forming catalyst was estimated to be approximately ~10.9 nm using the Scherer equation. The XRD characterization results show that the method reported in Comparative Example 2 cannot directly prepare a nickel-based forming catalyst with a metallic Ni crystal phase.

[0048] Comparative Example 3

[0049] SiO2 powder (Qingdao Baishahe Company) was placed in a nitric acid solution (1 mol L). -1 The mixture was stirred at room temperature for 3 hours, then washed with deionized water until the pH of the filtrate was neutral. It was then placed in an oven and dried thoroughly at 120 °C for 6 hours. Finally, the powder was placed in a muffle furnace and heated to 600 °C at a rate of 5 °C / min, and calcined at this temperature for 8 hours to obtain the desired SiO2 support (specific surface area = 337.0 m²). 2 / g, pore volume = 0.8 cm 3 / g, pore size = 9.9 nm).

[0050] 1.66 g Ni(NO3)2·6H2O, 3.5 g polyethylene glycol (PEG, average molecular weight = 1000), 2 g melamine, 30 cm 3 n-Butanol and 90 cm 3 Deionized water was mixed under stirring and then refluxed at 120°C for 2 hours. 0.78 g of SiO2 powder was added under stirring. The solvent was then evaporated at 120°C until a paste-like sample was formed.

[0051] 10.5 g of 68% GR pure concentrated nitric acid solution, 12.2 g of GR pure citric acid solid, and 21.0 g of AR pure polyethylene glycol 400 were dissolved in 454.0 g of deionized water to obtain a kneading solution. The paste sample, SB powder, and montmorillonite were mixed in a ratio of paste:SB powder:montmorillonite = 10:2:1. The kneading solution was added dropwise at a water-to-paste mass ratio of 1.6 drops, and the mixture was kneaded into a ball to obtain a wet gel. The wet gel was extruded into uniform wet strips using a syringe (2 mm inner diameter) and allowed to dry naturally at room temperature in a ventilated area for 6 h, followed by drying at 55 °C for 12 h. The green body was placed in a tube furnace and calcined at 550 °C for 4 h under a N2 atmosphere to obtain the nickel-based molding catalyst Ni@CN / SiO2-CX-3.

[0052] The XRD pattern of the catalyst is attached. Figure 4 As shown. The broad diffraction peak at 2θ ≈ 20 - 25° can correspond to amorphous SiO2. The diffraction peaks appearing at 2θ ≈ 44.6°, 51.9°, and 76.5° can be attributed to the (111), (200), and (220) crystal planes of metallic Ni, indicating that metallic Ni crystal phase still exists in this nickel-based forming catalyst. The Ni content in the nickel-based forming catalyst was estimated using the Scherer equation. 0 The particle size is approximately ~15.5 nm. XRD characterization results show that the method reported in Comparative Example 3 can be used to prepare nickel-based shaped catalysts containing metallic Ni crystalline phases.

[0053] Comparative Example 4

[0054] SiO2 powder (Qingdao Baishahe Company) was placed in a nitric acid solution (1 mol L). -1 The mixture was stirred at room temperature for 3 hours, then washed with deionized water until the pH of the filtrate was neutral. It was then placed in an oven and dried thoroughly at 120 °C for 6 hours. Finally, the powder was placed in a muffle furnace and heated to 600 °C at a rate of 5 °C / min, and calcined at this temperature for 8 hours to obtain the desired SiO2 support (specific surface area = 337.0 m²). 2 / g, pore volume = 0.8 cm 3 / g, pore size = 9.9 nm).

[0055] 1.66 g Ni(NO3)2·6H2O, 3.5 g polyethylene glycol (PEG, average molecular weight = 1000), 2 g melamine, 30 cm 3 n-Butanol and 90 cm 3Deionized water was mixed under stirring and then refluxed at 120°C for 2 h. 0.78 g of SiO2 powder was added under stirring. The solvent was then evaporated at 120°C until a paste-like sample was formed. The resulting precursor was placed in a tube furnace and calcined at 550°C for 4 h in a flowing N2 atmosphere. After cooling, it was ground into 140-160 mesh powder to obtain the supported nickel-based catalyst powder.

[0056] 10.5 g of 68% GR pure concentrated nitric acid solution, 12.2 g of GR pure citric acid solid, and 21.0 g of AR pure polyethylene glycol 400 were dissolved in 454.0 g of deionized water to obtain a kneading solution. Catalyst powder, SB powder, and montmorillonite were mixed in a ratio of catalyst:SB powder:montmorillonite = 10:2:1. The mixture was added dropwise to the kneading solution at a water-to-powder mass ratio of 1.1 drops, and kneaded into a ball to obtain a wet gel. The wet gel was extruded into uniform wet strips using a syringe (2 mm inner diameter) and allowed to dry naturally at room temperature in a ventilated area for 6 h, followed by drying at 55 °C for 12 h. The green body was then placed in a tube furnace and calcined at 550 °C for 4 h in air. The calcined catalyst was then immersed in a 20% PEG-1000 aqueous solution and dried at 80 °C. The dried sample was placed in a tube furnace and calcined at 550 °C for 4 h under N2 atmosphere to obtain the nickel-based forming catalyst Ni@CN / SiO2-CX-4.

[0057] The XRD pattern of the catalyst is attached. Figure 5 As shown. The broad diffraction peak at 2θ ≈ 20 - 25° can correspond to amorphous SiO2. The diffraction peaks appearing at 2θ ≈ 44.3°, 51.8° and 76.3° can be attributed to the (111), (200) and (220) crystal planes of metallic Ni, indicating that NiO can be reduced to metallic Ni by PEG-1000. The Ni content in the nickel-based forming catalyst was estimated by the Scherer equation. 0 The particle size is approximately ~11.4 nm. XRD characterization results show that the method reported in Comparative Example 4 can be used to prepare nickel-based shaped catalysts containing metallic Ni crystalline phases.

[0058] Example 2

[0059] This invention uses a YHKC-2A particle strength tester (Taizhou Yinhe Instrument Factory) to determine the lateral compressive strength of the nickel-based molded catalysts prepared in the above examples and comparative examples. First, the prepared nickel-based molded catalysts were divided into 10-15 particles with a length of 4-6 mm. The length of each particle was measured using calipers and recorded as l (mm). These particles were placed in the center of the particle strength tester's tray. The peak value F′ (N) when the particles were crushed was then measured and recorded. Finally, the lateral compressive strength of the final molded catalyst was calculated according to the People's Republic of China Chemical Industry Standard (HG / T 2782-2024).

[0060] The specific calculations are as follows: (1) Radial crushing force F, expressed in Newtons per centimeter (N / cm). (2) F =

[0061] In the formula: F′ — The value displayed by the intelligent particle strength tester when the sample is crushed, in Newtons (N); l — The numerical value of the sample length, in centimeters (cm); (3) Average radial crushing force The values ​​are expressed in Newtons per centimeter (N / cm). (4) F= i

[0062] In the formula: F i —The radial crushing force of the i-th particle, expressed in Newtons per centimeter (N / cm); n — the number of particles determined in group l of samples.

[0063] After strength testing, the lateral compressive strength of the nickel-based molded catalyst prepared in Example 1 was 64.8 N / cm. In comparison, the lateral compressive strength of the Ni@CN / SiO2-CX-1 catalyst prepared in Comparative Example 1 was 35.5 N / cm. The comparison between Example 1 and Comparative Example 1 shows that the mass ratio of catalyst powder to binder has a significant impact on the lateral compressive strength of the nickel-based molded catalyst. The Ni@CN / SiO2-CX-2 catalyst prepared in Comparative Example 2 was very brittle. The comparison between Example 1 and Comparative Example 2 shows that the calcination atmosphere has a significant impact on both the crystal phase and the lateral compressive strength of the nickel-based molded catalyst. The lateral compressive strength of the Ni@CN / SiO2-CX-3 catalyst prepared in Comparative Example 3 was 6.4 N / cm. The comparison between Example 1 and Comparative Example 3 shows that the preparation method of the supported nickel-based catalyst powder has a significant impact on the lateral compressive strength of the nickel-based molded catalyst. While one-step molding can yield nickel-based molded catalysts containing metallic Ni crystalline phases, their lateral compressive strength is not high. The Ni@CN / SiO2-CX-4 catalyst prepared in Comparative Example 4 has a lateral compressive strength of 22.2 N / cm. A comparison of Comparative Examples 2 and 4 shows that impregnation with PEG-1000 can not only reduce NiO in the air-calcined molded catalyst to metallic Ni, but also improve its lateral compressive strength. This indicates that the presence of the metallic Ni crystalline phase has a significant impact on improving the lateral compressive strength of the molded catalyst.

[0064] Example 3

[0065] Stainless steel high-pressure reactor (100 cm) 3 The nickel-based molded catalyst and nickel-based catalyst powder prepared in Example 1 were subjected to a performance evaluation test on the catalytic hydrogenation reaction of p-chloronitrobenzene. First, 50 mL of anhydrous ethanol and 1.0 g of... p -CNB and 0.2 g of catalyst were added to a high-pressure reactor. Before the reaction, the reactor system was first purged six times with high-purity H2 (99.999%), and then hydrogenation was carried out under magnetic stirring (1000 rpm), 373 K, and 1.1 MPa. The hydrogenation products were qualitatively and quantitatively analyzed using a gas chromatograph (Agilent GC7890B) equipped with a flame ionization detector. The hydrogenation experimental results showed that the original catalyst powder... p -CNB achieves ~100% conversion in 90 minutes. p- The CAN selectivity was ~95.7%. Using the Ni@CN / SiO2-CX catalyst prepared in Example 1, at 90 minutes... p- CNB conversion rate can reach 97.35%. p The selectivity of CAN was 95.23%. After 120 minutes of reaction...p- The CNB conversion rate reached ~99.22%. p The selectivity of -CAN is ~95.21%. The above experimental results show that the nickel-based molding catalyst prepared by the method shown in this invention has both high mechanical strength and active centers for the hydrogenation reaction of metallic Ni.

Claims

1. A process for the preparation of a supported nickel-based shaped catalyst, characterized in that: The preparation method includes the following steps: (a) SiO2powder with a specific surface area of not less than 300 m 2 / g is added to a nitric acid solution for treatment, and then the desired SiO2carrier is obtained by filtration, washing, drying and high-temperature calcination; (b) Dissolve the nickel salt, polyethylene glycol, and nitrogen-containing organic compound in deionized water and n-butanol, and reflux the mixture in an oil bath at 100-120°C for 1-2 hours to obtain a mixed solution; the nickel salt is one of nickel nitrate hexahydrate, anhydrous nickel sulfate, nickel sulfate hexahydrate, nickel sulfate heptahydrate, and nickel chloride hexahydrate; the polyethylene glycol has a molecular weight of 1000-2000; the nitrogen-containing organic compound is one of melamine and urea; based on the total mass of the nickel salt, polyethylene glycol, and nitrogen-containing organic compound as 100%, the mass percentage of the nickel salt is 20-25%, the mass percentage of the polyethylene glycol is 45-50%, and the mass percentage of the nitrogen-containing organic compound is 25-30%. (c) Under stirring conditions, SiO2 support is added to the mixture obtained in step (b), and then evaporated to dryness to obtain a paste-like precursor, such that the theoretical nickel loading is 20-40 wt%, where the theoretical loading = m Ni ÷(m Ni +m SiO2载体 )×100%, where m Ni and m SiO2载体 These refer to the mass of nickel and the mass of the SiO2 support in the mixed aqueous solution, respectively. (d) The paste-like precursor obtained in step (c) is calcined at 500-600℃ for 4-5 hours under an inert atmosphere, and then cooled and ground to obtain a supported nickel-based catalyst powder. (e) Dissolve the adhesive solvent and the extrusion aid in deionized water to obtain a kneading solution; the adhesive solvent is a combination of citric acid and concentrated nitric acid; the extrusion aid is one or more of polyethylene glycol 400, guar gum powder, and starch; in the kneading solution, the mass percentages of the adhesive solvent and the extrusion aid are 1wt% to 5wt% and 1wt% to 10wt%, respectively. (f) Take the supported nickel-based catalyst powder obtained in step (d) and mix it with the binder. Add the kneading liquid dropwise to the mixture of supported nickel-based catalyst powder and binder in a certain proportion, and continuously squeeze and knead to ensure that the powder particles are fully and evenly mixed with the kneading liquid to obtain a wet gel. The binder is boehmite or a mixture of boehmite and montmorillonite. The mass ratio of the supported nickel-based catalyst powder to the binder is 1:0.4 to 0.

5. The water-powder mass ratio of the kneading liquid to the mixture of catalyst powder and binder is 1.0 to 1.

5. (g) Extrude the wet gel into uniform wet strips and dry them to obtain a green body; (h) The green body is placed in a tube furnace and calcined at 500-590°C for 3-5 hours under an inert atmosphere to obtain a supported nickel-based forming catalyst.

2. The production method according to claim 1, characterized by: In step (b), the nickel salt is nickel nitrate hexahydrate, the polyethylene glycol is polyethylene glycol-1000, and the nitrogen-containing organic compound is melamine.

3. The production method according to claim 1, wherein: In step (d), the inert atmosphere is a nitrogen atmosphere, and the high-temperature calcination conditions are: calcination temperature of 550℃ and calcination time of 4h.

4. The production method according to claim 1, wherein: In step (e), the mass ratio of concentrated nitric acid to citric acid in the adhesive solvent is 1:1 to 2.

5. The production method according to claim 1, wherein: In step (f), the binder is a mixture of boehmite and montmorillonite, with a mass ratio of 2:

1.

6. The production method according to claim 1, wherein: The water-to-powder mass ratio of the kneading liquid to the mixture of catalyst powder and binder in step (f) is 1.1-1.

3.

7. The production method according to claim 6, characterized by: The water-to-powder mass ratio of the kneading liquid to the mixture of catalyst powder and binder in step (f) is 1.

1.

8. The production method according to claim 1, wherein: In step (i), the inert atmosphere is a nitrogen atmosphere, and the high-temperature calcination conditions are: calcination temperature of 550°C and calcination time of 4 hours.

9. A supported nickel-based molding catalyst prepared by the preparation method according to any one of claims 1-8.

10. The application of the supported nickel-based molding catalyst as described in claim 9 in the catalytic hydrogenation reaction of p-chloronitrobenzene.

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