Preparation method and application of a hydrogenation reaction catalyst

Abstract

This invention provides a method for preparing and applying a hydrogenation reaction catalyst, relating to the field of catalyst technology. Using nitrates, sodium carbonate, PEG 2000, and other raw materials, this invention obtains a hydrogenation reaction catalyst through mixing, calcination, and passivation steps. This invention improves the catalyst by doping it with Zr, overcoming the problem of easy sintering and deactivation in Ni-based catalysts, reducing Ni agglomeration, increasing Ni dispersibility, effectively improving the dispersion of the active components, reducing catalyst particle size, and improving reaction efficiency and stability. Therefore, the catalyst prepared by this invention possesses high catalytic activity and stability.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a method for preparing and applying a hydrogenation reaction catalyst. Background Technology

[0002] Hydrogen energy is an abundant, green, low-carbon, and widely applicable secondary energy source that plays a vital role in reducing greenhouse gas emissions such as carbon dioxide. Hydrogen energy is environmentally friendly and has the advantages of sustainable development; its chemical reaction produces only water, resulting in zero pollution, high efficiency, and suitability for long-distance transportation.

[0003] Currently, key technologies for hydrogen energy lie in three areas: hydrogen production, hydrogen storage and transportation, and fuel cell technology. Hydrogen energy is characterized by high gravimetric energy density but low volumetric energy density. The key to its storage and transportation technology development lies in how to increase the energy density of hydrogen while ensuring safety and economy. Organic liquid hydrogen storage, with its safety, convenience, and high density, has great development potential and is an important research direction.

[0004] Traditional organic liquid hydrogen storage materials mainly utilize aromatic compounds such as benzene, toluene, naphthalene, and dibenzyltoluene. However, their commercialization is limited due to high reaction temperatures and the presence of side reactions. Catalytic hydrogenation commonly uses noble metal catalysts such as Ru, Rh, Pd, and Pt. While these catalysts exhibit good catalytic performance, they are costly and difficult to industrialize. Therefore, developing highly active and low-cost hydrogenation catalysts is crucial for current organic liquid hydrogen storage technology. Non-noble metal catalysts primarily utilize transition metals such as Fe, Co, Ni, and Cu as their active components. Ni-based catalysts have attracted considerable attention due to their excellent catalytic properties, but their application is limited by their tendency to sinter and deactivate. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method for preparing a hydrogenation reaction catalyst. By optimizing the catalyst composition and preparation process, the method solves the problem of Ni-based catalysts being deactivated due to easy sintering, which limits their application, and ensures that the catalyst has high catalytic activity and stability.

[0006] The method for preparing the catalyst of the present invention includes the following steps:

[0007] (1) Dissolve nitrate in deionized water and stir until homogeneous to obtain solution A; dissolve sodium carbonate in deionized water and stir until homogeneous to obtain solution B; dissolve PEG 2000 in deionized water and stir until homogeneous to obtain solution C.

[0008] (2) Under oil bath conditions, slowly add solution A and solution B to solution C while stirring continuously to form a light green precipitate. After the addition is complete, continue stirring for 30 minutes. After stirring is complete, remove the reaction vessel, cool it to room temperature, and filter it. Wash the precipitate with deionized water and anhydrous ethanol alternately until the pH of the filtrate is 7-8.

[0009] (3) The washed precipitate is uniformly dispersed in anhydrous ethanol. After dispersion, the anhydrous ethanol is removed at 120°C to obtain a light green powder. The light green powder is pulverized and passed through a 200-mesh sieve to obtain a catalyst precursor.

[0010] (4) The catalyst precursor is calcined at high temperature. After calcination, it is cooled to room temperature. Then the catalyst precursor is reduced. After reduction, it is cooled to room temperature and passivated. After passivation, the hydrogenation reaction catalyst is obtained.

[0011] Furthermore, in step (1), the nitrate is one or more of nickel nitrate, aluminum nitrate, and zirconium nitrate.

[0012] Further, in step (1), the concentration of nickel nitrate in solution A is 1.87 g / 100 mL, the concentration of aluminum nitrate is 5.85 g / 100 mL, 5.69 g / 100 mL, 5.52 g / 100 mL, 5.35 g / 100 mL, 5.18 g / 100 mL or 5.02 g / 100 mL, and the concentration of zirconium nitrate is 0.11 g / 100 mL, 0.22 g / 100 mL, 0.33 g / 100 mL, 0.44 g / 100 mL or 0.55 g / 100 mL.

[0013] Furthermore, in step (1), the concentration of sodium carbonate in solution B is 3 g / 100 mL.

[0014] Furthermore, in step (1), the concentration of PEG 2000 in solution C is 0.5 g / 100 mL.

[0015] Furthermore, in step (1), the volume ratio of solution A, solution B, and solution C is 1.5:1.5:1.

[0016] Furthermore, in step (2), the oil bath temperature is 90°C.

[0017] Furthermore, in step (4), the high-temperature calcination temperature is 600℃, the calcination time is 1h, and the heating rate is 5℃ / min. In this invention, the water in the catalyst precursor is removed by high-temperature calcination to obtain a stable catalyst precursor.

[0018] Furthermore, in step (4), the reduction treatment temperature is 650℃, the reduction treatment time is 6h, and the heating rate is 5℃ / min. This invention reduces nickel oxide to metallic nickel through reduction treatment, thereby improving the catalytic hydrogenation activity.

[0019] Furthermore, in step (4), the reduction treatment is carried out in a 10% H2 / Ar mixed atmosphere with a mixed gas flow rate of 50 mL / min.

[0020] Furthermore, in step (4), the passivation treatment is carried out in a 10% O2 / Ar mixed atmosphere, the passivation temperature is room temperature, and the passivation time is 1 hour.

[0021] The present invention also provides a hydrogenation reaction catalyst prepared according to the above method.

[0022] Another object of the present invention is to provide the application of the catalyst in the hydrogenation reaction of the hydrogen storage material N-propylcarbazole, specifically including the following steps:

[0023] The air inside the reactor was purged and high-purity H2 was introduced to prevent an explosion during the reaction. N-propylcarbazole was mixed with cyclohexane and then hydrogenated under stirring.

[0024] Furthermore, the catalyst is added in an amount of 10 wt% of N-propylcarbazole.

[0025] Furthermore, the hydrogenation reaction temperature is 150°C, the hydrogenation reaction pressure is 7 MPa, and the stirring speed is 600 r / min.

[0026] This invention selects the transition metal Ni as the active component, reducing the catalyst preparation cost. Simultaneously, this invention employs a co-precipitation method to increase the Ni loading. However, since Ni-based catalysts are prone to sintering and deactivation, this invention introduces Zr to reduce Ni agglomeration and increase Ni dispersibility. This effectively improves the dispersion of the active component, reduces catalyst particle size, and enhances reaction efficiency and stability, resulting in a catalyst with high catalytic activity and stability.

[0027] This invention introduces mesoporous alumina into the catalyst, whose large specific surface area and good thermal stability make it an excellent support for optimizing Ni-based catalysts. Furthermore, ZrO2 possesses good hydrothermal stability and high oxygen vacancies, which can optimize the performance of the catalyst support of this invention. Combined with Al2O3, the catalyst support exhibits high redox performance, sintering resistance, and good thermal stability. Compared with the prior art, the beneficial technical effects of this invention are:

[0028] (1) This invention restricts the sintering and carbon deposition of Ni nanoparticles, improves the hydrogenation performance of hydrogen storage materials, and is used for the hydrogenation reaction of organic liquid hydrogen storage material N-propylcarbazole (NPCZ).

[0029] (2) The catalyst of the present invention is a non-precious metal catalyst, which has a lower raw material cost;

[0030] (3) The catalyst of the present invention has high catalytic activity and stability, and still has good hydrogenation activity after being repeatedly cycled 10 times.

[0031] (4) The synthesis process of this invention is simple, the preparation is simple, and the requirements for personnel and equipment are low, which can realize large-scale production and application. Attached Figure Description

[0032] The present invention will be further described below with reference to the accompanying drawings.

[0033] Figure 1 The X-ray diffraction patterns are those of the catalysts in Examples 1-6 of this invention;

[0034] Figure 2 The hydrogenation reaction rates of the catalysts in Examples 1-6 of this invention;

[0035] Figure 3 This is a transmission electron microscope image of the catalyst in Example 4 of the present invention;

[0036] Figure 4 The hydrogenation rate of the catalyst in Test Example 2 of this invention is the rate of hydrogenation after 10 cycles.

[0037] Figure 5 The hydrogenation rate of the catalyst in Example 3 of this invention is the rate of hydrogenation after 10 cycles. Detailed Implementation

[0038] The technical solution provided by the present invention will be further described below with reference to the embodiments.

[0039] The catalysts in the examples were measured using an Agilent 7890 gas chromatograph with an autosampler.

[0040] Example 1

[0041] Weigh 4.4595g Ni(NO3)2·6H2O (0.015mol) and 15.4530g Al(NO3)3·9H2O, dissolve them in 150mL of deionized water, and name this solution A. Weigh 12.2615g Na2CO3, dissolve it in 150mL of deionized water, and name this solution B. Weigh 0.5g PEG2000, dissolve it in 100mL of deionized water, and name this solution C. Place the beaker containing solution C in an oil bath. Under 90℃ oil bath conditions, slowly add solutions A and B dropwise to solution C simultaneously, stirring constantly, until a light green precipitate forms. After titration, continue stirring for 30min, filter, and wash the precipitate with deionized water and anhydrous ethanol until the pH of the filtrate is 7. Then, disperse the precipitate in 300mL of anhydrous ethanol, and evaporate the anhydrous ethanol in the solution to dryness in an oil bath at 120℃ to obtain a light green powder. The catalyst precursor was obtained by grinding the powder and sieving it through a 200-mesh sieve. The catalyst precursor was placed in a muffle furnace and heated to 600℃ at a heating rate of 5℃ / min for 1 hour. After cooling to room temperature, it was removed and placed in a tube furnace. Under a 10% H2 / Ar mixed atmosphere, the temperature was increased to 650℃ at a heating rate of 5℃ / min for 6 hours, with a mixer flow rate of 50 mL / min. After cooling to room temperature, the catalyst was passivated by passing a 10% O2 / Ar mixed gas for 1 hour, thus obtaining the Ni / Al2O3 hydrogenation catalyst.

[0042] Testing revealed that the Ni loading in the hydrogenation catalyst prepared in this example was 30%.

[0043] Example 2

[0044] Weigh 4.4595g Ni(NO3)2·6H2O, 15.0115g Al(NO3)3·9H2O, and 0.2090g Zr(NO3)4·5H2O, and dissolve them in 150mL of deionized water, naming this solution A. Weigh 12.1357g Na2CO3 and dissolve it in 150mL of deionized water, naming this solution B. Weigh 0.5g PEG2000 and dissolve it in 100mL of deionized water, naming this solution C. Place the beaker containing solution C in an oil bath. Under 90℃ oil bath conditions, slowly add solutions A and B dropwise to solution C simultaneously, stirring constantly, until a light green precipitate forms. After titration, continue stirring for 30min, filter, and wash the precipitate with deionized water and anhydrous ethanol until the pH of the filtrate is 7. Then disperse the precipitate in 300mL of anhydrous ethanol, and evaporate the anhydrous ethanol in the solution to dryness in an oil bath at 120℃ to obtain a light green powder. The catalyst precursor was obtained by grinding the powder and sieving it through a 200-mesh sieve. The catalyst precursor was placed in a muffle furnace and heated to 600℃ at a heating rate of 5℃ / min for 1 hour. After cooling to room temperature, it was removed and placed in a tube furnace. Under a 10% H2 / Ar mixed atmosphere, the temperature was increased to 650℃ at a heating rate of 5℃ / min for 6 hours, with a mixer flow rate of 50 mL / min. After cooling to room temperature, the catalyst was passivated by passing a 10% O2 / Ar mixed gas for 1 hour, thus obtaining the Ni / Al2O3-ZrO2-hydrogenation catalyst.

[0045] Testing revealed that the hydrogenation catalyst prepared in this example contained 30% Ni and 2 wt% ZrO2.

[0046] Example 3

[0047] Weigh 4.4595g Ni(NO3)2·6H2O, 14.5700g Al(NO3)3·9H2O, and 0.4181g Zr(NO3)4·5H2O, and dissolve them in 150mL of deionized water, naming this solution A. Weigh 12.0098g Na2CO3 and dissolve it in 150mL of deionized water, naming this solution B. Weigh 0.5g PEG2000 and dissolve it in 100mL of deionized water, naming this solution C. Place the beaker containing solution C in an oil bath. Under 90℃ oil bath conditions, slowly add solutions A and B dropwise to solution C simultaneously, stirring constantly, until a light green precipitate forms. After titration, continue stirring for 30 minutes, filter, and wash the precipitate with deionized water and anhydrous ethanol until the pH of the filtrate is 7. Then disperse the precipitate in 300mL of anhydrous ethanol, and evaporate the anhydrous ethanol in the obtained solution to dryness in an oil bath at 120℃ to obtain a light green powder. The catalyst precursor was obtained by grinding the powder and sieving it through a 200-mesh sieve. The catalyst precursor was placed in a muffle furnace and heated to 600℃ at a heating rate of 5℃ / min for 1 hour. After cooling to room temperature, it was removed and placed in a tube furnace. Under a 10% H2 / Ar mixed atmosphere, the temperature was increased to 650℃ at a heating rate of 5℃ / min for 6 hours, with a mixer flow rate of 50 mL / min. After cooling to room temperature, the catalyst was passivated by passing a 10% O2 / Ar mixed gas for 1 hour, thus obtaining the Ni / Al2O3-ZrO2 hydrogenation catalyst.

[0048] Testing revealed that the hydrogenation catalyst prepared in this example contained 30% Ni and 4 wt% ZrO2.

[0049] Example 4

[0050] Weigh 4.4595g Ni(NO3)2·6H2O, 14.1285g Al(NO3)3·9H2O, and 0.6271g Zr(NO3)4·5H2O, and dissolve them in 150mL of deionized water, naming this solution A. Weigh 11.8840g Na2CO3 and dissolve it in 150mL of deionized water, naming this solution B. Weigh 0.5g PEG2000 and dissolve it in 100mL of deionized water, naming this solution C. Place the beaker containing solution C in an oil bath. Under 90℃ oil bath conditions, slowly add solutions A and B dropwise to solution C simultaneously, stirring constantly, until a light green precipitate forms. After titration, continue stirring for 30 minutes, filter, and wash the precipitate with deionized water and anhydrous ethanol until the pH of the filtrate is 7. Then disperse the precipitate in 300mL of anhydrous ethanol, and evaporate the anhydrous ethanol in the obtained solution to dryness in an oil bath at 120℃ to obtain a light green powder. The catalyst precursor was obtained by grinding the powder and sieving it through a 200-mesh sieve. The catalyst precursor was placed in a muffle furnace and heated to 600℃ at a heating rate of 5℃ / min for 1 hour. After cooling to room temperature, it was removed and placed in a tube furnace. Under a 10% H2 / Ar mixed atmosphere, the temperature was increased to 650℃ at a heating rate of 5℃ / min for 6 hours, with a mixer flow rate of 50 mL / min. After cooling to room temperature, the catalyst was passivated by passing a 10% O2 / Ar mixed gas for 1 hour, thus obtaining the Ni / Al2O3-ZrO2 hydrogenation catalyst.

[0051] Testing revealed that the hydrogenation catalyst prepared in this example contained 30% Ni and 6 wt% ZrO2.

[0052] Example 5

[0053] Weigh 4.4595g Ni(NO3)2·6H2O, 13.6869g Al(NO3)3·9H2O, and 0.8362g Zr(NO3)4·5H2O, and dissolve them in 150mL of deionized water, naming this solution A. Weigh 11.7581g Na2CO3 and dissolve it in 150mL of deionized water, naming this solution B. Weigh 0.5g PEG 2000 and dissolve it in 100mL of deionized water, naming this solution C. Place the beaker containing solution C in an oil bath. Under 90℃ oil bath conditions, slowly add solutions A and B dropwise to solution C simultaneously, stirring constantly, until a light green precipitate forms. After titration, continue stirring for 30 minutes, filter, and wash the precipitate with deionized water and anhydrous ethanol until the pH of the filtrate is 7. Then disperse the precipitate in 300mL of anhydrous ethanol, and evaporate the anhydrous ethanol in the solution to dryness in an oil bath at 120℃ to obtain a light green powder. The catalyst precursor was obtained by grinding the powder and sieving it through a 200-mesh sieve. The catalyst precursor was placed in a muffle furnace and heated to 600℃ at a heating rate of 5℃ / min for 1 hour. After cooling to room temperature, it was removed and placed in a tube furnace. Under a 10% H2 / Ar mixed atmosphere, the temperature was increased to 650℃ at a heating rate of 5℃ / min for 6 hours, with a mixer flow rate of 50 mL / min. After cooling to room temperature, the catalyst was passivated by passing a 10% O2 / Ar mixed gas for 1 hour, thus obtaining the Ni / Al2O3-ZrO2 hydrogenation catalyst.

[0054] Testing revealed that the hydrogenation catalyst prepared in this example contained 30% Ni and 8 wt% ZrO2.

[0055] Example 6

[0056] Weigh 4.4595g Ni(NO3)2·6H2O, 13.2454g Al(NO3)3·9H2O, and 1.0452g Zr(NO3)4·5H2O, dissolve them in 150mL of deionized water, and name this solution A. Weigh 11.6323g Na2CO3, dissolve it in 150mL of deionized water, and name this solution B. Weigh 0.5g PEG2000, dissolve it in 100mL of deionized water, and name this solution C. Place the beaker containing solution C into an oil bath. Solutions A and B were simultaneously and slowly added dropwise to solution C under a 90℃ oil bath with continuous stirring, forming a light green precipitate. After titration, stirring was continued for 30 min. The solution was filtered, and the precipitate was washed with deionized water and anhydrous ethanol until the pH of the filtrate reached 7-8. The precipitate was then dispersed in 300 mL of anhydrous ethanol, and the anhydrous ethanol in the solution was evaporated to dryness in a 120℃ oil bath to obtain a light green powder. The powder was ground and sieved through a 200-mesh sieve to obtain the catalyst precursor. The catalyst precursor was placed in a muffle furnace and heated to 600℃ at a heating rate of 5℃ / min for 1 h. After cooling to room temperature, the catalyst was removed and placed in a tube furnace. Under a 10% H2 / Ar mixed atmosphere, the temperature was increased at a rate of 5℃ / min to 650℃ for 6 hours. The flow rate of the mixer was 50 mL / min. After cooling to room temperature, the catalyst was passivated by passing a 10% O2 / Ar mixed gas for 1 hour to obtain the Ni / Al2O3-ZrO2 hydrogenation catalyst.

[0057] Testing revealed that the hydrogenation catalyst prepared in this example contained 30% Ni and 10 wt% ZrO2.

[0058] Test Example 1

[0059] 0.2 g of each of the catalysts prepared in Examples 1-6 were weighed for catalytic hydrogenation experiments of N-propylcarbazole. The steps were as follows: 2 g of N-propylcarbazole was added to 40 mL of cyclohexane, and the hydrogenation reaction was carried out at 7 MPa, 150 °C, and a rotation speed of 600 r / min. The changes in hydrogenation rate of NPCZ catalyzed by different catalysts over time are shown in the figure. Figure 2 As shown.

[0060] Test Example 2

[0061] 0.2 g of the Ni / Al₂O₃-ZrO₂-6% catalyst prepared in Example 1 was used to conduct a cyclic catalytic hydrogenation experiment on N-propylcarbazole. The steps were as follows: 2 g of N-propylcarbazole was added to 40 mL of cyclohexane, and the hydrogenation reaction was carried out at 7 MPa, 150 °C, and a rotation speed of 600 r / min. Samples were taken periodically during the reaction, and their components were analyzed by gas chromatography. After the reaction, the catalyst was washed with n-hexane until no N-propylcarbazole or its hydrogenation products were found in the washed n-hexane. The same hydrogenation experiment was repeated 10 times with the washed catalyst. The hydrogenation rate of N-propylcarbazole during the experiment was as follows: Figure 4 As shown.

[0062] Test Example 3

[0063] 0.2 g of the Ni / Al₂O₃ catalyst prepared in Example 1 was used to conduct a cyclic catalytic hydrogenation experiment on N-propylcarbazole. The steps were as follows: 2 g of N-propylcarbazole was added to 40 mL of cyclohexane, and the hydrogenation reaction was carried out at 7 MPa, 150 °C, and a rotation speed of 600 r / min. Samples were taken periodically during the reaction, and their components were analyzed by gas chromatography. After the reaction, the catalyst was washed with n-hexane until no N-propylcarbazole or its hydrogenation product was found in the washed n-hexane. The same hydrogenation experiment was repeated 10 times with the washed catalyst. The hydrogenation rate of N-propylcarbazole during the experiment was as follows: Figure 5 As shown.

[0064] Depend on Figure 4 and 5 It can be seen that the catalyst in Test Example 2 was still able to complete the hydrogenation of N-propylcarbazole within 120 minutes during the 10th cycle of hydrogenation, indicating that the catalyst activity did not decline significantly and it exhibited good stability and catalytic activity. The catalyst in Test Example 3 showed significant activity decline during the 10 cycles of hydrogenation and could not complete the hydrogenation within 120 minutes.

[0065] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. The application of a hydrogenation reaction catalyst in the hydrogenation reaction of N-propylcarbazole, a hydrogen storage material, characterized in that, Includes the following steps: The air inside the reactor was purged and high-purity H2 was introduced to prevent an explosion during the reaction. N-propylcarbazole was mixed with cyclohexane and then hydrogenated under stirring conditions. The preparation method of the hydrogenation reaction catalyst includes the following steps: (1) Dissolve nitrate in deionized water and stir until homogeneous to obtain solution A; dissolve sodium carbonate in deionized water and stir until homogeneous to obtain solution B; dissolve PEG2000 in deionized water and stir until homogeneous to obtain solution C. The nitrate is one or more of nickel nitrate, aluminum nitrate, and zirconium nitrate; (2) Slowly add solution A and solution B to solution C under 90℃ oil bath conditions and stir continuously to form a light green precipitate. After the addition is complete, continue stirring for 30 min. After stirring is complete, remove the reaction vessel and cool it to room temperature and filter it. Wash the precipitate with deionized water and anhydrous ethanol alternately until the pH of the filtrate is 7-8. (3) The washed precipitate is uniformly dispersed in anhydrous ethanol. After dispersion, the anhydrous ethanol is removed at 120°C to obtain a light green powder. The light green powder is pulverized and passed through a 200-mesh sieve to obtain a catalyst precursor. (4) The catalyst precursor is calcined at high temperature. After calcination, it is cooled to room temperature. Then the catalyst precursor is reduced. After reduction, it is cooled to room temperature and passivated. After passivation, the hydrogenation reaction catalyst is obtained. In the hydrogenation catalyst, the Ni loading is 30% and the ZrO2 content is 6wt%.

2. The application according to claim 1, characterized in that, In step (1), the sodium carbonate concentration in solution B is 3 g / 100 mL.

3. The application according to claim 1, characterized in that, In step (1), the concentration of PEG2000 in solution C is 0.5 g / 100 mL.

4. The application according to claim 1, characterized in that, In step (1), the volume ratio of solution A, solution B, and solution C is 1.5:1.5:

1.

5. The application according to claim 1, characterized in that, In step (4), the high-temperature calcination temperature is 600℃, the calcination time is 1h, and the heating rate is 5℃ / min; the reduction treatment temperature is 650℃, the reduction treatment time is 6h, and the heating rate is 5℃ / min.

6. The application according to claim 1, characterized in that, In step (4), the reduction treatment is carried out in a 10% H2 / Ar mixed atmosphere with a mixed gas flow rate of 50 mL / min, and the passivation treatment is carried out in a 10% O2 / Ar mixed atmosphere with a passivation temperature of room temperature and a passivation time of 1 h.

7. The application according to claim 1, characterized in that, The catalyst was added at a rate of 10 wt% of N-propylcarbazole.

8. The application according to claim 1, characterized in that, The hydrogenation reaction temperature is 150℃, the hydrogenation reaction pressure is 7 MPa, and the stirring speed is 600 r / min.

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