Preparation method and application of NiMo-based aromatic hydrocarbon hydrogenation catalyst

Abstract

The invention discloses a preparation method and application of a NiMo-based aromatic hydrocarbon hydrogenation catalyst. According to the present invention, aluminum nitride is firstly adopted as a catalyst carrier to be applied to an aromatic hydrocarbon hydrogenation reaction, and by controlling the addition amount of urea, the morphology-controllable (petal-shaped nanosheet-to-fibrous nanorod) NiMo (at) ALN catalyst is prepared, and the NiMo (at) ALN catalyst comprises a nanometer aluminum nitride carrier and a hydrogenation active component; the preparation method comprises the following steps: carrying out in-situ growth on parent nano aluminum nitride by adopting a hydrothermal method to prepare a carrier with nanosheets / nanorods, introducing nickel salt and molybdenum salt under the condition of stirring in a water bath for 24 hours, and then calcining and reducing a dried sample to obtain the NiMo-coated ALN catalyst. The catalyst has hydrogenation activity comparable to that of noble metal without vulcanization, can realize hydrogenation saturation of aromatic hydrocarbon under low-temperature and low-pressure conditions, and has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of aromatic hydrocarbon hydrogenation saturation technology, specifically relating to a method for preparing and applying a NiMo-based aromatic hydrocarbon hydrogenation catalyst. Background Technology

[0002] my country's characteristics of being "rich in coal, poor in oil, and lacking in gas" determine that coal is a crucial basic energy source. Among these, low-temperature coal tar produced by coal pyrolysis has aromatic carbon numbers similar to those of aviation jet fuel. After hydrogenation, it can be used to prepare coal-based jet fuel, which is rich in cycloalkanes, has a low freezing point, good thermal stability, and does not carbonize at 500℃. It can replace petroleum-based fuels and become an important strategic energy reserve for my country. Therefore, vigorously developing the hydrogenation of low-temperature coal tar to prepare special fuels is of great research significance. Low-temperature coal tar is rich in aromatics, and the cycloalkanes and hydrogenated aromatics produced by the hydrogenation saturation of aromatics are ideal components of coal-based jet fuels. However, during the ring-by-ring hydrogenation saturation process, the increase in resonance energy, the increase in steric hindrance, and the competitive adsorption of intermediate products make it difficult to hydrogenate the final ring of aromatics to the final ring during this process.

[0003] Regarding the active components for hydrogenation, noble metal catalysts exhibit strong capabilities in dissociating hydrogen atoms and activating aromatic molecules, and can be used at low temperatures and low pressures (200°C). o The complete hydrogenation of aromatics under conditions of 1 MPa (C) has attracted widespread attention from researchers. However, noble metal catalysts have poor sulfur and nitrogen resistance and are easily poisoned. For example, Chinese patent CN109261201A discloses a method to improve the sulfur resistance of noble metal catalysts: encapsulating a metal cluster inside a core-shell structured LTA-type molecular sieve to avoid direct contact between the active component and sulfides, thereby improving the catalyst's sulfur resistance. However, noble metal catalysts are expensive and difficult to apply on a large scale.

[0004] Sulfide catalysts with Co-Mo, Ni-Mo, or Ni-W as active components and alumina as the support have become widely used hydrogenation catalysts in industry due to their excellent sulfur and nitrogen resistance and low cost. These catalysts typically operate at temperatures between 300-400 °C. oComplete hydrogenation of aromatics can only be achieved under conditions of 3-7 MPa (C), and pre-sulfurization is required to achieve high hydrogenation activity. Currently, two main pre-sulfurization methods are used: in-vessel and external. The in-vessel method is simple to operate, but uses toxic and corrosive sulfiding agents, which can easily damage equipment and is difficult to control, leading to uneven sulfidation. The external method is carried out in specialized equipment, offering controllable conditions, more complete sulfidation, and avoiding equipment corrosion, but requires specialized equipment and is more expensive. Both methods involve toxic substances, are complex, and have high overall costs. To overcome the shortcomings of traditional pre-sulfurization, researchers have developed "fully sulfided catalysts," which integrate the sulfidation process into the preparation stage by introducing sulfiding agents during synthesis, thus eliminating the need for subsequent pre-sulfurization steps. For example, patent ZL200510046431.2 combines preparation and sulfidation by stepwise loading of active components and adding elemental sulfur for heat treatment. Tian Zhijian's research group synthesized MoS2 / C nanomaterials with a specific structure using thiourea as a sulfur source via a hydrothermal method. This catalyst can achieve a phenanthrene conversion rate of 87% without sulfidation. Patent CN115337939A promotes the dispersion and in-situ sulfidation of active metals by introducing CO2 and propylene oxide into a hydrothermal environment, resulting in a catalyst with an aromatic saturation rate of 55.6% without additional sulfidation. Although such catalysts avoid subsequent sulfidation, their preparation process usually still requires the introduction of organic sulfur, hydrothermal treatment, and reaction under high temperature and high pressure, resulting in a common problem of complex processes and insufficiently mild conditions.

[0005] In terms of catalyst supports, alumina is widely used due to its low cost and stable structure. However, its irregular pore structure and limited specific surface area can lead to uneven dispersion of active components, affecting the hydrogenation depth. Furthermore, its high L-acid content can easily cause coking. Moreover, alumina is not an inert support and can interact with active metals such as Ni and Mo to form spinel phases such as CoAl2O4 and NiAl2O4, hindering the formation of the active Co-Mo-S phase and significantly reducing the catalyst's hydrogenation activity. To address the inherent defects of alumina supports, researchers are constantly exploring various modification strategies to improve its catalytic performance. Currently reported modification methods mainly include acid-base regulation, surface modification, and sulfidation optimization. These methods each have their own characteristics but also corresponding limitations.

[0006] Patent CN201610333041.1 introduces boron into an alumina support via a hydrothermal method, effectively improving the dispersion of the active components and adjusting the ratio of Levinic acid (L-acid) to Benzoic acid (B-acid). However, the high B-acid content in the modified support still leads to a decrease in diesel yield. Patent CN112619676A uses phosphorus and an alkaline modifier for composite modification of alumina. By optimizing the amount of alkaline modifier and hydrothermal conditions, it significantly reduces the acid content of the support. Simultaneously, the alkaline environment's etching effect on the support surface increases the specific surface area. However, this method involves cumbersome synthesis steps and requires high reaction temperatures and pressures to achieve the desired hydrogenation effect. Patent CN115337939A addresses the problem of insufficient sulfidation in sulfidated catalysts by innovatively introducing carbon dioxide and propylene oxide under high pressure to prepare a fully sulfidated catalyst via hydrothermal synthesis. While this method significantly improves the sulfidation degree and hydrogenation activity of the catalyst, the complex preparation process limits its industrial application prospects. Although these methods have improved the inherent defects of alumina supports to some extent, they still inevitably suffer from problems such as complex preparation processes and harsh reaction conditions.

[0007] Aluminum nitride (AlN), as a typical covalent nitride, exhibits a diamond-like structure due to the highly polarized Al-N covalent bonds in its crystal structure. This unique bonding mode endows AlN with excellent intrinsic properties, including outstanding high-temperature stability, excellent resistance to molten metal erosion, and outstanding thermal conductivity, thus making it of significant application value in the fields of thermal shock resistant ceramics and high-temperature structural materials.

[0008] It is worth noting that AlN not only possesses the aforementioned structure-performance advantages, but its high thermal conductivity can effectively suppress the thermal sintering effect of catalysts in high-temperature reactions. Simultaneously, the amino functional groups on its surface can regulate the acidity of the support surface. These characteristics give it unique potential in the field of heterogeneous catalysis. Taking the strongly endothermic dry reforming of methane as an example, this reaction has long been limited by problems such as carbon deposition and the aging of active metal particles, severely hindering its industrial application.

[0009] Patent CN201911082611 describes a core-shell structured aluminum nitride catalyst, which anchors the active component at the core-shell interface through a spatial confinement strategy, significantly suppressing the metal sintering and carbon deposition deactivation problems of traditional Al2O3-based catalysts. Patent CN202110250208 utilizes the hydrolysis properties of AlN to prepare a highly dispersed Pt-M / AlN catalyst for the dehydrogenation of light alkanes. Compared to the traditional Pt-M / γ-Al2O3 system, this catalyst not only maintains higher catalytic stability but also significantly improves olefin selectivity, attributed to the optimized regulation of metal-support interactions by the AlN support. However, despite the aforementioned advantages of AlN in catalysis, research on its use as an active component support is currently limited, and even fewer patents apply aluminum nitride as a support in the hydrogenation of aromatics. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing and applying a NiMo-based aromatic hydrocarbon hydrogenation catalyst. For the first time, aluminum nitride is used as a catalyst precursor in the aromatic hydrocarbon hydrogenation reaction. By controlling the amount of urea added, a NiMo@ALN catalyst with controllable morphology (from petal-like nanosheets to fibrous nanorods) is prepared. The distribution of the active phase is regulated by the support effect, improving mass transfer during the reaction and thus significantly enhancing catalytic efficiency. Furthermore, the preparation process does not require sulfidation, exhibiting good environmental friendliness.

[0011] To address the problems in the existing technology, the technical solution adopted by this invention is as follows:

[0012] A method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst includes the following steps:

[0013] S1. The nitride powder is heated in air at 600°C. o The nitride precursor was obtained by calcination at C for 4 h.

[0014] S2. Dissolve 0.3-0.9 g of urea and 0.005 mol of Ni(NO3)2·6H2O in deionized water, sonicate for 8 min, then add 2 g of nitride powder, stir magnetically for 10 min, and then transfer the obtained solution to a polytetrafluoroethylene-lined autoclave and incubate at 130°C. o Hydrothermal treatment at C conditions for 4-12 hours;

[0015] S3. Cool to 20-30 degrees Celsius. o After step C, collect the solid product, wash with deionized water until neutral, and place it in an oven at 90°C. o Dry at C overnight, and finally heat the precursor in a muffle furnace at 450°C. o Calcination at C for 4 h;

[0016] S4. Introduce the calcined support into Ni(NO3)2.6H2O and (NH4)6Mo7O 24 In a mixed aqueous solution of .4H2O, at 20 o C-60 o Stir at C for 24 h;

[0017] S5. The above solution was dried at 105 °C for 12 h and calcined at 400 °C for 4 h to obtain NiMo@nitride catalyst.

[0018] Furthermore, in step S1, the nitride is aluminum nitride, boron nitride, or silicon nitride.

[0019] Furthermore, the nitride is aluminum nitride, and the aluminum nitride is 99.9% metal-based with a particle size of 50 nm.

[0020] Furthermore, in step S2, the amount of urea added is 0.6 g, and the hydrothermal time is 8 h.

[0021] Furthermore, in step S4, the Ni / Mo molar ratio is 0.25-2:1.

[0022] Furthermore, in step S4, the Ni / Mo molar ratio is 0.5.

[0023] Furthermore, in step S4, the sum of the masses of nickel oxide and molybdenum oxide in the catalyst accounts for 20 wt% of the mass of the NiMo@nitride catalyst.

[0024] Furthermore, in step S4, the nickel salt is Ni(NO3)2·6H2O, and the molybdenum salt is (NH4)6Mo7O. 24 .4H2O.

[0025] A method for hydrogenating and saturating polycyclic aromatic hydrocarbons, using a NiMo-based aromatic hydrocarbon hydrogenation catalyst prepared by any of the above methods, in a hydrogen gas stream of 100 ml / min for 500 minutes. o C reduction for 3 h yielded the reduced catalyst; a 5 wt% naphthalene / n-hexane solution was then introduced, and the catalyst was reacted at 160–240 °C. o C, hydrogen partial pressure 0.5–3.0 MPa, hydrogen-to-oil volume ratio 100–600:1, liquid hourly space velocity 3 h⁻¹ -1 The hydrogenation reaction is carried out under the following conditions.

[0026] Beneficial effects:

[0027] Compared with existing technologies, the NiMo-based aromatic hydrocarbon hydrogenation catalyst, its preparation method, and its application, as described in this invention, have the following advantages:

[0028] 1. Innovative Breakthrough in Carrier Selection

[0029] This invention is the first to introduce aluminum nitride (ALN) as a precursor into an aromatic hydrocarbon hydrogenation catalytic system, breaking through the technical limitations of traditional hydrogenation catalysts that use oxides such as alumina and silicon dioxide as supports. It provides a novel support material with higher stability and controllability, while significantly expanding the design space of hydrogenation catalysts.

[0030] 2. Shape controllability design

[0031] By precisely controlling the amount of urea added, the morphology of the catalyst support was controllably prepared, and a series of morphological structures ranging from petal-shaped nanosheets to fibrous nanorods were successfully constructed. This innovative design provides a new technical means for the distribution control of the active phase of the catalyst.

[0032] 3. Significant performance optimization

[0033] Compared to traditional NiMo catalysts, which require operation at high temperatures and pressures of 300 °C and 3-5 MPa, the catalyst of this invention can maintain high catalytic activity under mild conditions of 200 °C and 1 MPa, significantly reducing energy consumption and demonstrating outstanding advantages in industrial applications. Attached Figure Description

[0034] Figure 1 XRD patterns of catalysts with different urea addition amounts;

[0035] Figure 2 XRD patterns of catalysts with different support types;

[0036] Figure 3 SEM images of catalysts with different urea addition amounts;

[0037] Figure 4 SEM images of catalysts with different support types;

[0038] Figure 5 These are performance test graphs for different types of catalysts. Detailed Implementation

[0039] The preparation method and its application scenarios of the present invention will be further described below through specific embodiments, but the scope of protection of the present invention includes, but is not limited to, the following embodiments.

[0040] Example 1

[0041] Aluminum nitride powder (99.9% metal-based, 50 nm particle size) was subjected to an air atmosphere at 600°C. o Aluminum nitride support was obtained by calcination at C for 4 h.

[0042] 0.3 g of urea and 1.4539 g of Ni(NO3)2·6H2O were dissolved in 10 ml of deionized water and sonicated for 8 min. Then, 2 g of nitride powder was added, and the mixture was magnetically stirred for 10 min. The resulting solution was then transferred to a polytetrafluoroethylene-lined autoclave and heated at 130 °C. o Hydrothermal treatment for 8 hours under C conditions.

[0043] After cooling to room temperature, collect the solid product, wash with deionized water until neutral, and place it in an oven at 90°C. o Dry at C overnight, and finally heat the precursor in a muffle furnace at 450°C. o Calcination at C for 4 hours.

[0044] The calcined support was introduced into a mixture of 0.4 g Ni(NO3)2·6H2O and 0.4870 g (NH4)6Mo7O 24 In a mixed aqueous solution composed of .4H2O, at 40 o Stir at C for 24 h.

[0045] The above solution was dried at 105 °C for 12 h and calcined at 400 °C for 4 h to obtain catalyst D.

[0046] Example 2

[0047] Aluminum nitride powder (99.9% metal-based, 50 nm particle size) was subjected to an air atmosphere at 600 °C. o Aluminum nitride support was obtained by calcination at C for 4 h.

[0048] 0.6 g of urea and 1.4539 g of Ni(NO3)2·6H2O were dissolved in 10 ml of deionized water and sonicated for 8 min. Then, 2 g of nitride powder was added, and the mixture was magnetically stirred for 10 min. The resulting solution was then transferred to a polytetrafluoroethylene-lined autoclave and heated at 130 °C. o Hydrothermal treatment for 8 hours under C conditions.

[0049] After cooling to room temperature, collect the solid product, wash with deionized water until neutral, and place it in an oven at 90°C. o Dry at C overnight, and finally heat the precursor in a muffle furnace at 450°C. o Calcination at C for 4 hours.

[0050] The calcined support was introduced into a mixture of 0.4 g Ni(NO3)2·6H2O and 0.4870 g (NH4)6Mo7O 24 In a mixed aqueous solution composed of .4H2O, at 40 o Stir at C for 24 h.

[0051] The above solution was dried at 105 °C for 12 h and calcined at 400 °C for 4 h to obtain catalyst E.

[0052] Example 3

[0053] Aluminum nitride powder (99.9% metal-based, 50 nm particle size) was subjected to an air atmosphere at 600 °C. o Aluminum nitride support was obtained by calcination at C for 4 h.

[0054] 0.9 g of urea and 1.4539 g of Ni(NO3)2·6H2O were dissolved in 10 ml of deionized water and sonicated for 8 min. Then, 2 g of nitride powder was added, and the mixture was magnetically stirred for 10 min. The resulting solution was then transferred to a polytetrafluoroethylene-lined autoclave and heated at 130 °C. o Hydrothermal treatment for 8 hours under C conditions.

[0055] After cooling to room temperature, collect the solid product, wash with deionized water until neutral, and place it in an oven at 90°C. o Dry at C overnight, and finally heat the precursor in a muffle furnace at 450°C. o Calcination at C for 4 hours.

[0056] The calcined support was introduced into a mixture of 0.4 g Ni(NO3)2·6H2O and 0.4870 g (NH4)6Mo7O 24 In a mixed aqueous solution composed of .4H2O, at 40 o Stir at C for 24 h.

[0057] The above solution was dried at 105 °C for 12 h and calcined at 400 °C for 4 h to obtain catalyst F.

[0058] Comparative Example 1

[0059] Alumina powder was placed in air at 600°C. o Alumina support was obtained by calcination at C for 4 h.

[0060] 0.6 g of urea and 1.4539 g of Ni(NO3)2·6H2O were dissolved in 10 ml of deionized water and sonicated for 8 min. Then, 2 g of alumina powder was added and the mixture was magnetically stirred for 10 min. The resulting solution was then transferred to a polytetrafluoroethylene-lined autoclave and heated at 130 °C. o Hydrothermal treatment for 8 hours under C conditions.

[0061] After cooling to room temperature, collect the solid product, wash with deionized water until neutral, and place it in an oven at 90°C. o Dry at C overnight, and finally heat the precursor in a muffle furnace at 450°C. o Calcination at C for 4 hours.

[0062] The calcined support was introduced into a mixture of 0.4 g Ni(NO3)2·6H2O and 0.4870 g (NH4)6Mo7O 24 In a mixed aqueous solution composed of .4H2O, at 40 o Stir at C for 24 h.

[0063] The above solution was dried at 105 °C for 12 h and calcined at 400 °C for 4 h to obtain catalyst A.

[0064] Comparative Example 2

[0065] Silica powder was placed in air at 600°C. o The silica support was obtained by calcination at C for 4 h.

[0066] Dissolve 0.6 g of urea and 1.4539 g of Ni(NO3)2·6H2O in 10 ml of deionized water, sonicate for 8 min, then add 2 g of silica powder, stir magnetically for 10 min, and then transfer the resulting solution to a polytetrafluoroethylene-lined autoclave and heat at 130 °C. o Hydrothermal treatment for 8 hours under C conditions.

[0067] After cooling to room temperature, collect the solid product, wash with deionized water until neutral, and place it in an oven at 90°C. o Dry at C overnight, and finally heat the precursor in a muffle furnace at 450°C. o Calcination at C for 4 hours.

[0068] The calcined support was introduced into a mixture of 0.4 g Ni(NO3)2·6H2O and 0.4870 g (NH4)6Mo7O 24 In a mixed aqueous solution composed of .4H2O, at 40 o Stir at C for 24 h.

[0069] The above solution was dried at 105 °C for 12 h and calcined at 400 °C for 4 h to obtain catalyst B.

[0070] Comparative Example 3

[0071] Aluminum nitride powder (99.9% metal-based, 50 nm particle size) was subjected to an air atmosphere at 600 °C. o Aluminum nitride support was obtained by calcination at C for 4 h.

[0072] 1.4539 g of Ni(NO3)2.6H2O was dissolved in 10 ml of deionized water and sonicated for 8 min. Then, 2 g of nitride powder was added, and the mixture was magnetically stirred for 10 min. The resulting solution was then transferred to a polytetrafluoroethylene-lined autoclave and heated at 130 °C. o Hydrothermal treatment for 8 hours under C conditions.

[0073] After cooling to room temperature, collect the solid product, wash with deionized water until neutral, and place it in an oven at 90°C. o Dry at C overnight, and finally heat the precursor in a muffle furnace at 450°C. o Calcination at C for 4 hours.

[0074] The calcined support was introduced into a mixture of 0.4 g Ni(NO3)2·6H2O and 0.4870 g (NH4)6Mo7O 24 In a mixed aqueous solution composed of .4H2O, at 40 o Stir at C for 24 h.

[0075] The above solution was dried at 105 °C for 12 h and calcined at 400 °C for 4 h to obtain catalyst C.

[0076] Comparative example:

[0077] Example 4

[0078] The performance of the catalysts prepared in Examples 1-3 and Comparative Examples 1-3 was tested for the hydrogenation reaction of naphthalene.

[0079] The evaluation raw material used was a 5 wt% naphthalene-n-hexane solution.

[0080] The hydrogenation performance of catalyst AF was evaluated using a 10 ml fixed-bed hydrogenation apparatus.

[0081] Catalyst reduction conditions: 100 ml / min hydrogen, 500 o C is restored in three hours.

[0082] Evaluation reaction conditions: reaction pressure 1 MPa, reaction temperature 220°C o C, hydrogen / oil volume ratio 600:1, liquid hourly space velocity 3h -1 The evaluation results are shown in Table 1 and Figure 5 As shown.

[0083] Table 1. Properties and evaluation results of the catalyst

[0084] catalyst Urea addition amount / g Naphthalene conversion rate (%) Tetrahydronaphthalene selectivity (%) Selectivity of decahydronaphthalene (%) A 0.6 72 40 60 B 0.6 50 72 28 C 0 83 27 73 D 0.3 87 12 88 E 0.6 95 10 90 F 0.9 73 26 74

[0085] Table 2 Specific surface area and pore structure of catalysts

[0086] catalyst <![CDATA[S BET (m 2 .g -1 ) a ]]> <![CDATA[V total (cm 3 .g -1 ) b ]]> <![CDATA[D poresize (nm) b ]]> <![CDATA[NiMo@A2O3-0.6]]> 210.715 0.423 7.799 <![CDATA[NiMo@SiO2-0.6]]> 201.437 0.372 6.828 NiMo@ALN-0 139.004 0.229 3.822 NiMo@ALN-0.3 143.913 0.239 3.794 NiMo@ALN-0.6 184.482 0.225 3.819 NiMo@ALN-0 156.022 0.213 2.806

[0087] like Figure 1 and Figure 2As shown, after hydrothermal treatment, the characteristic diffraction peaks of aluminum nitride (AlN), alumina (Al2O3), and silicon dioxide (SiO2) still exist, indicating that their crystal structure has not changed significantly. The specific surface area of ​​the catalyst prepared using aluminum nitride as a support initially increases and then decreases with increasing urea addition. When the urea addition is 0.6 g, the specific surface area of ​​the catalyst reaches its maximum value (184.482 m²·g⁻¹), which is beneficial for uniform dispersion of active species. BET test results show that the catalysts prepared using alumina and silicon dioxide as supports have larger average pore sizes and pore volumes than those prepared using aluminum nitride as a support. However, excessively large pore sizes and volumes may increase the diffusion resistance of reactants within the pores, thereby exacerbating catalyst coking and deactivation.

[0088] Combined with SEM analysis ( Figure 2 As can be seen, without the addition of urea, the support exhibits a partially aggregated, randomly stacked nanosheet morphology. With increasing urea content, irregular aggregation decreases, and the nanosheets gradually grow into regular rod-like structures, at which point the catalyst's specific surface area reaches its maximum. This unique morphology formed by the random stacking of highly mesoporous rod-like structures not only promotes the dispersion and exposure of active species but also optimizes the mass transfer efficiency during the reaction process, thus exhibiting optimal hydrogenation activity (95% naphthalene conversion and 90% decahydronaphthalene selectivity) under low temperature and low pressure conditions. However, when the urea content is further increased to 0.9 g, the support morphology transforms into flower-shaped aggregates assembled from rod-like structural units, leading to a decrease in specific surface area and pore size, which is detrimental to the uniform distribution of active species, thus significantly reducing hydrogenation activity.

[0089] Furthermore, the hydrogenation activities (conversion rate of naphthalene and selectivity of decahydronaphthalene) of catalysts A and B are much lower than those of catalyst E, as shown by SEM analysis ( Figure 4 As can be seen, when alumina is used as the support, the catalyst exhibits an overall agglomerated state, with a small number of rod-like structures visible locally; while when silica is used as the support, the catalyst mainly exhibits an amorphous agglomerate state, and no obvious regular morphology is observed. This agglomeration phenomenon leads to low dispersion of active species, insufficient exposure of effective active sites, and exacerbates mass transfer limitations, thereby reducing the hydrogenation activity of the catalyst.

[0090] In summary, this invention is the first to apply aluminum nitride as a catalyst precursor in the hydrogenation reaction of aromatics. By controlling the amount of urea added, a NiMo@ALN catalyst with controllable morphology (from petal-shaped nanosheets to fibrous nanorods) was prepared. The distribution of the active phase was regulated by the support effect, which improved the mass transfer in the reaction process and thus significantly improved the catalytic efficiency.

Claims

1. A method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst, characterized in that, Includes the following steps: S1. The nitride powder is heated in air at 600°C. o The nitride precursor was obtained by calcination at C for 4 h. S2. Dissolve 0.3-0.9 g of urea and 0.005 mol of Ni(NO3)2·6H2O in deionized water, sonicate for 8 min, then add 2 g of nitride powder, stir magnetically for 10 min, and then transfer the obtained solution to a polytetrafluoroethylene-lined autoclave and incubate at 130°C. o Hydrothermal treatment at C conditions for 4-12 hours; S3. After cooling to 20-30℃, collect the solid product, wash with deionized water until neutral, and place in an oven at 90℃. o Dry at C overnight, and finally heat the precursor in a muffle furnace at 450°C. o Calcination at C for 4 h; S4. The calcined support is introduced into a mixed aqueous solution of nickel and molybdenum salts, and at 20°C... o C-60 o Stir at C for 24 h; S5. The above solution was dried at 105 °C for 12 h and calcined at 400 °C for 4 h to obtain NiMo@nitride catalyst.

2. The method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst according to claim 1, characterized in that, In step S1, the nitride is aluminum nitride, boron nitride, or silicon nitride.

3. The method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst according to claim 2, characterized in that, The nitride is aluminum nitride, and the aluminum nitride is 99.9% metal-based with a particle size of 50 nm.

4. The method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst according to claim 1, characterized in that, In step S2, the amount of urea added is 0.6 g, and the hydrothermal time is 8 h.

5. The method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst according to claim 1, characterized in that, In step S4, the Ni / Mo molar ratio is 0.25-2:

1.

6. The method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst according to claim 5, characterized in that, In step S4, the Ni / Mo molar ratio is 0.

5.

7. The method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst according to claim 1, characterized in that, In step S4, the combined mass of nickel oxide and molybdenum oxide in the catalyst accounts for 20 wt% of the mass of the NiMo@nitride catalyst.

8. The method for preparing a NiMo-based aromatic hydrocarbon hydrogenation catalyst according to claim 7, characterized in that, In step S4, the nickel salt is Ni(NO3)2.6H2O, and the molybdenum salt is (NH4)6Mo7O. 24 .4H2O.

9. A method for hydrogenating and saturating polycyclic aromatic hydrocarbons, characterized in that, The NiMo-based aromatic hydrocarbon hydrogenation catalyst prepared by any one of claims 1-8 was subjected to a hydrogen gas flow of 100 ml / min for 500 minutes. o C reduction for 3 h yielded the reduced catalyst; a 5 wt% naphthalene / n-hexane solution was then introduced, and the catalyst was reacted at 160–240 °C. o C, hydrogen partial pressure 0.5–3.0 MPa, hydrogen-to-oil volume ratio 100–600:1, liquid hourly space velocity 3 h⁻¹ -1 The hydrogenation reaction is carried out under the following conditions.

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