A catalyst for hydrodearomatization of waste lubricating oil and a method for preparing the same

Abstract

The application discloses a catalyst for hydrodearomatization of waste lubricating oil and a preparation method thereof. The catalyst comprises a carrier and an active component supported on the carrier. The carrier is a hierarchical pore with a (3-aminopropyl)triethoxysilane functional group grafted on the surface, and has a dual-pore structure of mesopore with a pore size of 8-12 nm and macropore with a pore size of 50-100 nm. The active component comprises Pt or Pd monatomic atoms with a loading amount of 0.1-0.5 wt% and Ni-Mo-P alloy nanoparticles, wherein the molar ratio of P to (Ni and Mo) is 0.1-0.4:1, the molar ratio of Ni to Mo is 2-4:1, and the size of the Ni-Mo-P alloy nanoparticles is 2-5 nm. The preparation method comprises the steps of carrier functionalization pretreatment, atomic layer deposition technology for loading monatomic atoms, preparation of ternary complex precursors, impregnation loading, step-by-step calcination and hydrogen reduction activation. The catalyst has excellent hydrodearomatization performance, and provides a new technical approach for efficient purification treatment of waste lubricating oil.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically a catalyst for the hydrodearomatization of waste lubricating oil and its preparation method. Background Technology

[0002] With industrial development and the increase in automobile ownership, the amount of waste lubricating oil generated is increasing year by year. Waste lubricating oil contains a large amount of aromatic compounds, which not only affect the performance of lubricating oil but also pollute the environment. Therefore, developing efficient hydrodearomatization technology for waste lubricating oil is of great significance for resource recycling and environmental protection.

[0003] Traditional hydrodearomatization catalysts typically employ Ni-Mo or Co-Mo bimetallic systems supported on alumina supports. However, these conventional catalysts suffer from several drawbacks: First, the metal active component exhibits low dispersion on the support surface, easily forming large particles and resulting in low utilization of active sites; second, the support's simple pore structure leads to high mass transfer resistance, affecting the diffusion of reactants and products; third, the catalyst exhibits poor selectivity, easily over-hydrogenating while removing aromatics, thus impacting product quality; and finally, the catalyst suffers from poor stability and is prone to deactivation during the reaction.

[0004] Existing catalyst preparation methods mainly employ equal-volume impregnation or co-precipitation methods, which struggle to precisely control the dispersion state and particle size of the active components. The support is typically a commercially available... Its pore structure is relatively simple and cannot well meet the mass transfer requirements of large molecular reactants. In addition, the metal components in catalysts prepared by traditional methods are prone to agglomeration, forming large metal particles, which reduces catalytic activity.

[0005] In recent years, single-atom catalysts have attracted widespread attention due to their unique electronic structure and maximized atom utilization. In single-atom catalysts, metal atoms exist in a monodisperse state, providing unique catalytic active sites. Meanwhile, alloy nanoparticles also exhibit excellent catalytic performance due to their synergistic effects. However, effectively combining single-atom and alloy nanoparticles to construct bifunctional catalytic systems with synergistic effects remains a technological challenge. Summary of the Invention

[0006] The purpose of this invention is to provide a catalyst for the hydrodearomatization of waste lubricating oil and its preparation method. The catalyst adopts a single-atom-alloy nanoparticle bifunctional active component system, combined with hierarchical pore support and surface functionalization technology, to achieve a high-activity, high-selectivity and high-stability hydrodearomatization reaction of waste lubricating oil, while having good anti-deactivation performance and long service life.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The catalyst for hydrodearomatization of waste lubricating oil according to the present invention comprises a support and an active component supported on the support, wherein:

[0009] The carrier is a hierarchical channel with 3-aminopropyltriethoxysilane functional groups grafted onto its surface. It has a dual-channel structure with mesopores (8-12 nm in diameter) and macropores (50-100 nm in diameter);

[0010] The active components include Pt or Pd single atoms and Ni-Mo-P alloy nanoparticles, wherein the loading of Pt or Pd single atoms is 0.1–0.5 wt%, the loading of Ni-Mo-P alloy nanoparticles is 8–18 wt%, the total molar ratio of P to Ni plus Mo is 0.1–0.4, the molar ratio of Ni to Mo is 2–4, and the size of the Ni-Mo-P alloy nanoparticles is 2–5 nm.

[0011] in:

[0012] The pore volume distribution of the support consists of 60-70% mesopores and 30-40% macropores, with a specific surface area of ​​180-250 m² / g. The hierarchical pore design significantly improves mass transfer performance. Mesopores provide a large specific surface area and abundant active sites, while macropores facilitate the rapid transport of large molecular reactants. The synergistic effect of both enhances catalytic efficiency.

[0013] Specifically, the total loading of Ni and Mo in the catalyst is 8-18 wt%, with Ni loading at 3-8 wt% and Mo loading at 5-10 wt%. By optimizing the metal loading, sufficient active sites are ensured while avoiding metal agglomeration caused by excessive loading.

[0014] Specifically, the Pt or Pd single atoms are anchored to the support surface through functional groups, and the Ni-Mo-P alloy nanoparticles have a size of 2-5 nm. The amino group in the 3-aminopropyltriethoxysilane functional group can form coordination bonds with the noble metal precursor, effectively anchoring the single atoms and preventing their aggregation. The introduction of P element can regulate the electronic structure of the Ni-Mo alloy, improving its hydrogenation activity and selectivity.

[0015] The present invention also provides a method for preparing the above-mentioned catalyst, comprising the following steps:

[0016] Carrier pretreatment, The support was functionalized with (3-aminopropyl)triethoxysilane at 80 °C for 4-6 h.

[0017] Single-atom loading: Pt or Pd single-atom precursors are loaded onto functionalized supports using atomic layer deposition (ALD) technology; preparation of phosphorus-modified metal precursors... and After complexing with citric acid, ammonium dihydrogen phosphate was added to prepare a P-Ni-Mo ternary complex precursor solution; impregnation loading was performed by contacting the precursor solution prepared in the previous step with the support for impregnation; stepwise calcination was performed by drying, pre-calcining at 300℃ for 2 h, and main calcination at 500℃ for 4 h; reduction treatment was performed by reducing at 400℃ for 3 h in a hydrogen atmosphere to obtain the catalyst.

[0018] Specifically, the atomic layer deposition (ALD) technique includes steps such as support pretreatment, precursor adsorption, first purging, reduction reaction, second purging, and repeated cycles. The support is placed in a hot-wall ALD reactor and heated to the reaction temperature under nitrogen protection; then... or The precursor vapor undergoes a chemical adsorption reaction with a pulse time of 0.5-2.0 seconds; unreacted precursors and byproducts are removed by purging with an inert gas for 10-30 seconds; hydrogen is introduced to carry out a reduction reaction to form metal atoms with a reduction pulse time of 1-5 seconds; the system is then purged with an inert gas again; the above steps are repeated until the target loading is reached, typically 10-50 cycles.

[0019] Specifically, the process parameters for atomic layer deposition are: reactor pressure 1-10 Torr, carrier preheating temperature 200-250℃, Pt precursor evaporation temperature 80-100℃, and Pd precursor evaporation temperature 120-150℃. The ALD reactor is a hot-wall reactor, which can provide a uniform temperature distribution and ensure uniform loading of single atoms.

[0020] Specifically, the heating rate in the stepwise calcination process is controlled at 2-5℃ / min, and the calcination atmosphere is air. Slow heating is beneficial for the gradual decomposition of the precursor and the formation of metal oxides, avoiding structural damage caused by rapid heating.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. A bifunctional system of single-atom-alloy nanoparticles achieves a synergistic catalytic effect. Pt or Pd single atoms provide active sites for hydrogen dissociation, while Ni-Mo-P alloy nanoparticles provide active sites for hydrogenation. The synergistic effect of the two significantly improves the activity and selectivity of hydrodearomatization.

[0023] 2. The hierarchical pore structure optimizes mass transfer performance. Mesopores provide a large specific surface area and abundant active sites, while macropores promote rapid transport of reactants. The dual-channel structure resolves the contradiction between activity and mass transfer, thereby improving catalytic efficiency.

[0024] 3. Surface functionalization technology enables precise anchoring of single atoms. The (3-aminopropyl)triethoxysilane functional group strongly anchors noble metal single atoms through chemical bonding, preventing them from agglomerating and deactivating during the reaction, and significantly improving the stability of the catalyst.

[0025] 4. Atomic layer deposition (ALD) technology ensures uniform dispersion of single atoms. By precisely controlling the number of deposition cycles and process parameters, atomic-level dispersion of precious metals on the carrier surface is achieved, maximizing the utilization rate of metal atoms.

[0026] 5. Phosphorus modification improves alloy properties. The introduction of phosphorus modulates the electronic structure of the Ni-Mo alloy, enhances the metal-support interaction, improves the dispersion and stability of alloy nanoparticles, and optimizes hydrogenation selectivity.

[0027] 6. The stepwise calcination process ensures optimal catalyst structure. Precise control of temperature and time achieves orderly decomposition of the precursor and uniform distribution of active components, avoiding excessive agglomeration of metal components. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to these embodiments. Those skilled in the art should recognize that the present invention covers all possible alternatives, improvements and equivalents within the scope of the claims.

[0029] The hierarchical pore structure was determined by a combination of nitrogen adsorption-desorption (BJH model) and mercury porosimetry: the volume fraction of mesopores (2-50 nm) was 65.3±2.0%, and the volume fraction of macropores (50-100 nm) was 34.7±2.0%. The adsorption-desorption isotherms showed superposition characteristics of H2-type hysteresis loops (mesopores) and H3-type hysteresis loops (macropores), confirming the coexistence of dual pore types.

[0030] The structure of the Ni-Mo-P alloy nanoparticles described below was verified by X-ray diffraction (XRD): a diffraction peak (PDF#00-054-0413) of the Ni-Mo-P alloy (111) crystal plane appeared at 2θ=44.5°±0.5°, with a full width at half maximum (FWHM) of 0.8° corresponding to a grain size of 3.2 nm. The presence of the MoP (2θ=43°) impurity phase peak confirms that P exists in the alloy as a solid solution.

[0031] The The original carrier parameters were: specific surface area 200±20 m² / g, pore volume 0.8±0.1 cm³ / g, and average pore size 12 nm. After modification with 3-aminopropyltriethoxysilane, the N 1s binding energy was measured to be 399.8 eV by X-ray photoelectron spectroscopy, corresponding to an amino grafting density of 1.15±0.05 mmol / g, confirming successful grafting of functional groups.

[0032] (3-Aminopropyl)triethoxysilane: purity ≥98%.

[0033] The remaining raw materials were analytical grade reagents with no special requirements and were all obtained through commercial purchases.

[0034] Example 1:

[0035] A method for preparing a catalyst for the hydrodearomatization of waste lubricating oil includes the following steps:

[0036] (1) Carrier pretreatment: 5g Disperse the sample in 50 mL of anhydrous toluene, add 0.25 g of 3-aminopropyltriethoxysilane, and reflux at 80 °C for 5 h. After filtration, wash successively with toluene and ethanol until no silicon is detected in the filtrate, and dry at 120 °C for 4 h.

[0037] (2) Single-atom loading: Pt single atoms were loaded using atomic layer deposition (ALD) technology. The functionalized support was placed in a hot-wall ALD reactor and heated to 225°C under nitrogen protection. Using a precursor (evaporation temperature 90℃), the pulse duration was 1.5 seconds, followed by nitrogen purging for 20 seconds, hydrogen reduction for 3 seconds, and nitrogen purging again for 20 seconds. This cycle was repeated 30 times to obtain a support with a Pt single atom loading of 0.3 wt%.

[0038] (3) Preparation of phosphorus-modified metal precursors: , Dissolve citric acid (3.84 g) in 100 mL of deionized water, stir at 80 °C until clear (forming a green complex, with a characteristic absorption peak at 620 nm observed in UV-Vis), then add... Continue stirring for 2 hours to obtain a transparent precursor solution.

[0039] (4) Impregnation loading: The precursor solution obtained in step (3) is impregnated with the Pt single-atom support obtained in step (2) by equal volume impregnation method for 4 hours, and then dried at 80°C for 12 hours.

[0040] (5) Step-by-step roasting: pre-roast at 300℃ for 2 hours with a heating rate of 3℃ / min, then roast at 500℃ for 4 hours with a heating rate of 3℃ / min. The roasting atmosphere is air.

[0041] (5) Reduction treatment: The catalyst was reduced to 400℃ for 3h at a rate of 5℃ / min under a hydrogen atmosphere (flow rate 50mL / min) and then cooled down.

[0042] Example 2:

[0043] The preparation method of a catalyst for the hydrodearomatization of waste lubricating oil differs from that in Example 1 only in that:

[0044] (1) Carrier pretreatment: 5g Disperse the sample in 50 mL of anhydrous toluene, add 0.15 g of 3-aminopropyltriethoxysilane, and reflux at 80 °C for 4 h. After filtration, wash successively with toluene and ethanol until no silicon is detected in the filtrate, and dry at 120 °C for 4 h.

[0045] (2) Single-atom loading: Pt single atoms were loaded using atomic layer deposition (ALD) technology. The functionalized support was placed in a hot-wall ALD reactor and heated to 200°C under nitrogen protection. Using a precursor (evaporation temperature 135℃), a pulse duration of 1.0 second, nitrogen purging for 15 seconds, hydrogen reduction for 2 seconds, and repeated 25 times, a support with a Pd single atom loading of 0.2wt% was obtained.

[0046] (3) Preparation of phosphorus-modified metal precursors: , Dissolve citric acid (3.84 g) in 100 mL of deionized water and stir at 80 °C until clear (forming a green complex; a characteristic absorption peak appears at 620 nm in UV-Vis). Add... Continue stirring for 2 hours to obtain a transparent precursor solution.

[0047] Example 3:

[0048] The preparation method of a catalyst for the hydrodearomatization of waste lubricating oil differs from that in Example 1 only in that:

[0049] (1) Carrier pretreatment: 5g Disperse the sample in 50 mL of anhydrous toluene, add 0.35 g of 3-aminopropyltriethoxysilane, and reflux at 80 °C for 6 h. After filtration, wash successively with toluene and ethanol until no silicon is detected in the filtrate, and dry at 120 °C for 4 h.

[0050] (2) Single-atom loading: Pt single atoms were loaded using atomic layer deposition (ALD) technology. The functionalized support was placed in a hot-wall ALD reactor and heated to 250°C under nitrogen protection. Using a precursor (evaporation temperature 100℃), a pulse duration of 2.0 seconds, nitrogen purging for 30 seconds, hydrogen reduction for 5 seconds, and 50 cycles were performed to obtain a support with a Pt single atom loading of 0.5wt%.

[0051] (3) Preparation of phosphorus-modified metal precursors: , Dissolve citric acid (3.84 g) in 100 mL of deionized water and stir at 80 °C until clear (forming a green complex; a characteristic absorption peak appears at 620 nm in UV-Vis). Add... Continue stirring for 2 hours to obtain a transparent precursor solution.

[0052] (5) Step-by-step roasting: pre-roast at 300℃ for 2 hours with a heating rate of 2℃ / min, and then roast at 500℃ for 4 hours with a heating rate of 3℃ / min. The roasting atmosphere is air.

[0053] Example 4:

[0054] The preparation method of a catalyst for the hydrodearomatization of waste lubricating oil differs from that in Example 1 only in that:

[0055] (2) Single-atom loading: Pt single atoms were loaded using atomic layer deposition (ALD) technology. The functionalized support was placed in a hot-wall ALD reactor and heated to 210°C under nitrogen protection. Using a precursor (evaporation temperature 90℃), the pulse duration was 0.5 seconds, followed by nitrogen purging for 20 seconds, hydrogen reduction for 3 seconds, and nitrogen purging again for 20 seconds. This cycle was repeated 15 times to obtain a support with a Pt single atom loading of 0.1 wt%.

[0056] (3) Preparation of phosphorus-modified metal precursors: , Dissolve citric acid (3.84 g) in 100 mL of deionized water and stir at 80 °C until clear (forming a green complex; a characteristic absorption peak appears at 620 nm in UV-Vis). Add... Continue stirring for 2 hours to obtain a transparent precursor solution.

[0057] (5) Step-by-step roasting: pre-roast at 300℃ for 2 hours with a heating rate of 5℃ / min, then roast at 500℃ for 4 hours with a roasting atmosphere of air.

[0058] Comparative Example 1:

[0059] The preparation method of a catalyst for the hydrodearomatization of waste lubricating oil differs from that in Example 1 only in that:

[0060] Step (1) Carrier pretreatment: Commercially purchased carriers were used directly. Carrier.

[0061] Comparative Example 2:

[0062] The preparation method of a catalyst for the hydrodearomatization of waste lubricating oil differs from that in Example 1 only in that:

[0063] Step (2) Single-atom loading: Instead of atomic layer deposition, noble metals are loaded using an equal-volume impregnation method. Solution impregnation of carrier.

[0064] Comparative Example 3:

[0065] The preparation method of a catalyst for the hydrodearomatization of waste lubricating oil differs from that in Example 1 only in that:

[0066] Step (3) Preparation of phosphorus-modified metal precursor: , Dissolve citric acid (3.84 g) in 100 mL of deionized water and stir at 80 °C until clear.

[0067] Comparative Example 4:

[0068] The preparation method of a catalyst for the hydrodearomatization of waste lubricating oil differs from that in Example 1 only in that:

[0069] Step (1) Carrier pretreatment: directly using traditional single-pore size Carrier (non-graded pore structure).

[0070] Comparative Example 5:

[0071] The preparation method of a catalyst for the hydrodearomatization of waste lubricating oil differs from that in Example 1 only in that:

[0072] Step (5) Step-by-step roasting: No step-by-step roasting is performed; the product is directly roasted at 500℃ for 4 hours.

[0073] The catalysts prepared in the examples and comparative examples were tested for their performance in the hydrodearomatization of waste lubricating oil.

[0074] Test conditions: reaction temperature 350℃, pressure 6.0MPa, hydrogen-to-oil ratio 800, liquid hourly space velocity (LISH). The reaction time is 100 hours.

[0075] Performance metrics:

[0076] Raw material: Waste lubricating oil was taken from the regeneration unit of a local petrochemical plant. The aromatic content (ASTM D6591) was 28.3 wt% and the sulfur content was <500 pm.

[0077] Reaction conditions: catalyst loading 1.0 g, reactor is a fixed bed stainless steel tube (inner diameter 8 mm), liquid hourly space velocity, hydrogen flow rate 50 mL / min (hydrogen-to-oil ratio 800).

[0078] Chromatographic analysis: Agilent 7890B gas chromatograph, HP-5 capillary column (30m×0.32mm×0.25μm), FID detector, internal standard method (n-dodecane) was used to quantify aromatic hydrocarbons.

[0079] Stability definition: After 100 h of continuous reaction, the percentage of aromatic hydrocarbon conversion retained (%) = (conversion at 100 h / initial conversion) × 100%.

[0080] (1) Aromatic hydrocarbon conversion rate: calculated by analyzing the change in aromatic hydrocarbon content before and after the reaction using gas chromatography.

[0081] (2) Product selectivity: Analyze the distribution of hydrogenation products and calculate the selectivity of the target product.

[0082] (3) Catalyst stability: Activity retention rate after 100 hours of continuous reaction, reaction conditions: 350℃, 6MPa. , .

[0083] Sampling interval: Samples were taken every 10 hours, and aromatic hydrocarbons were quantified by gas chromatography (Agilent 7890B, HP-5 column) using the internal standard method (n-dodecane).

[0084] (4) Metal dispersion: determined by CO chemical adsorption method;

[0085] Sample pretreatment: 0.1 g catalyst, Switch after restoration Purge until the baseline is stable.

[0086] CO pulse conditions: 0.1 mL / pulse, pulse interval 60 s, calculate the dispersity after subtracting the adsorption of blank carrier.

[0087]

[0088] Table 1. Catalytic performance test results

[0089]

[0090] According to the data in Table 1, the catalysts prepared in Examples 1-4 all exhibited excellent catalytic performance in the hydrodearomatization reaction of waste lubricating oil. The aromatic conversion rate all exceeded 90%, the product selectivity all exceeded 89%, the stability all exceeded 93%, and the metal dispersion all exceeded 85%. All performance indicators were significantly better than those of the comparative examples, indicating that the technical solution of the present invention has significant advantages.

[0091] Comparative Example 1, lacking carrier functionalization, resulted in poor single-atom anchoring of the precious metal, low metal dispersion, and a significant decrease in catalytic performance. Comparative Example 2, using a traditional impregnation method instead of atomic layer deposition, could not achieve precise single-atom loading, resulting in improved performance but still falling short of the examples. Comparative Example 3 lacked the electronic regulation effect of phosphorus, leading to poor alloy performance. Comparative Example 4 used a single-pore support, limiting mass transfer performance. Comparative Example 5 did not employ stepwise calcination, resulting in an insufficiently optimized catalyst structure. The results of these comparative examples fully demonstrate the necessity and synergistic effect of the various technical features of this invention.

[0092] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A catalyst for the hydrodearomatization of waste lubricating oil, characterized in that, The catalyst comprises a support and an active component supported on the support, wherein: The carrier precursor is hierarchical γ-Al2O3 with 3-aminopropyltriethoxysilane functional groups grafted onto its surface, and has a dual-channel structure of mesopores with a pore size of 8–12 nm and macropores with a pore size of 50–100 nm. The pore volume distribution of the carrier is as follows: mesopores account for 60–70%, macropores account for 30–40%, and the specific surface area is 180–250 m² / g. The active components include Pt or Pd single atoms and Ni-Mo-P alloy nanoparticles, wherein the loading of Pt or Pd single atoms is 0.1–0.5 wt%, the loading of Ni-Mo-P alloy nanoparticles is 8–18 wt%, the total molar ratio of P to Ni plus Mo is 0.1–0.4:1, the molar ratio of Ni to Mo is 2–4:1, and the size of the Ni-Mo-P alloy nanoparticles is 2–5 nm. The catalyst is prepared by the following steps: (1) Support pretreatment: The γ-Al2O3 support was functionalized with 3-aminopropyltriethoxysilane at 80℃ for 4-6h; (2) Single-atom loading: Pt or Pd single-atom precursors are loaded onto functionalized supports using atomic layer deposition technology; (3) Preparation of phosphorus-modified metal precursors: Ni(NO3)2·6H2O and (NH4)6Mo7O 24 • After complexing with citric acid, 4H2O was added to prepare a P-Ni-Mo ternary complex precursor solution. (4) Impregnation load: The precursor solution obtained in step (3) is impregnated with the carrier obtained in step (2); (5) Stepwise roasting: The impregnated sample is dried, pre-roasted at 300℃ for 2 hours, and then roasted at 500℃ for 4 hours. (6) Reduction treatment: The catalyst was obtained by reduction at 400℃ for 3 hours in a hydrogen atmosphere.

2. The catalyst for hydrodearomatization of waste lubricating oil according to claim 1, characterized in that, The total loading of Ni and Mo in the catalyst is 8–18 wt%, of which Ni is 3–8 wt% and Mo is 5–10 wt%.

3. The catalyst for hydrodearomatization of waste lubricating oil according to claim 1, characterized in that, The Pt or Pd single atoms are anchored to the carrier surface through functional groups, and the Ni-Mo-P alloy nanoparticles have a size of 2-5 nm.

4. The catalyst for hydrodearomatization of waste lubricating oil according to claim 1, characterized in that, The specific steps of the atomic layer deposition technology are as follows: (1) Carrier pretreatment: The carrier is placed in a hot-wall ALD reactor and heated to the reaction temperature under nitrogen protection; (2) Precursor adsorption: H2PtCl6·6H2O or Pd(hfac)2 precursor vapor is introduced to carry out chemical adsorption reaction, with a pulse time of 0.5-2.0 seconds; (3) First purging: Use inert gas to purge to remove unreacted precursors and byproducts for 10-30 seconds; (4) Reduction reaction: Hydrogen gas is introduced to carry out a reduction reaction to form metal atoms. The reduction pulse time is 1-5 seconds. (5) Second purging: Purge again with inert gas; (6) Repeat steps (2)-(5) until the target load is reached, 10-50 cycles.

5. The catalyst for hydrodearomatization of waste lubricating oil according to claim 4, characterized in that: The process parameters for atomic layer deposition are as follows: reactor pressure 1-10 Torr, carrier preheating temperature 200-250℃, Pt precursor evaporation temperature 80-100℃, and Pd precursor evaporation temperature 120-150℃.

6. The catalyst for hydrodearomatization of waste lubricating oil according to claim 4, characterized in that: The ALD reactor is a hot-wall reactor.

7. The catalyst for hydrodearomatization of waste lubricating oil according to claim 1, characterized in that, The heating rate during the step-by-step roasting process is controlled at 2-5℃ / min, and the roasting atmosphere is air.

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