Catalyst for selective hydrogenation of phthalic esters, process for its preparation and use

Abstract

The present application relates to a catalyst for selective hydrogenation of phthalate, a preparation method and application thereof, the catalyst comprising a carrier and a noble metal component and a non-noble metal component supported on the carrier, the carrier being a metal oxide with ordered mesoporous structure, the noble metal component being Ru, and the non-noble metal component being at least one selected from non-noble metals in group VIII. The catalyst is used for selective hydrogenation of phthalate, can realize efficient selective hydrogenation of phthalate, and obtain a high-purity cyclohexane dicarboxylate product.

Description

Technical Field

[0001] This invention relates to the field of phthalate hydrogenation, specifically to a catalyst for the selective hydrogenation of phthalates, its preparation method, and its application. Background Technology

[0002] Dioctyl phthalate (DOP) is one of the most commonly used phthalate plasticizers, widely used worldwide with a year-on-year growth trend. This widespread use has raised serious concerns about its safety. Studies have found that phthalates are significant endocrine disruptors, persistent organic pollutants that not only possess reproductive toxicity similar to estrogen but can also cause birth defects and cancer. They can enter the human body through inhalation, ingestion, and skin contact, harming human health. Therefore, the development of non-toxic, biodegradable plasticizer alternatives has attracted widespread attention. Cyclohexane-1,2-dicarboxylate, a selective hydrogenation product of phthalates, not only possesses superior properties similar to phthalate plasticizers but is also biologically non-toxic, non-carcinogenic, and does not bioaccumulate, making it an ideal environmentally friendly plasticizer.

[0003] The hydrogenation of phthalates, under specific reaction conditions and with the aid of a catalyst, selectively hydrogenates the benzene ring of phthalates to cyclohexanedicarboxylate. The key to this hydrogenation method lies in a highly efficient selective hydrogenation catalyst. Currently reported catalysts mainly include supported noble metal catalysts (such as Rh, Ru, Pd, and Pt), nickel-based catalysts, bimetallic catalysts, and polymetallic catalysts. Among these, noble metal catalysts exhibit the best performance but are more expensive. Furthermore, because phthalates are soluble in organic solvents but insoluble in water, and benzene-based plasticizers have high boiling points, liquid-phase hydrogenation is typically the only option. This process is prone to loss of active components and results in slow hydrogenation rates, often requiring high hydrogenation pressures. Therefore, catalysts with higher hydrogenation activity and selectivity for the target product are essential. Thus, developing efficient, continuous, green hydrogenation catalysts and processes for phthalates is of significant practical importance. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of low catalyst activity and low target product selectivity in the above-mentioned technologies, and to provide a catalyst for the selective hydrogenation of phthalate esters, its preparation method and application. This catalyst can effectively improve the dispersion of metal components and promote the diffusion of substances, thereby increasing the yield of cyclohexanedicarboxylate products.

[0005] This invention provides a catalyst for the selective hydrogenation of phthalates, wherein the catalyst comprises a support and a noble metal component and a non-noble metal component supported on the support. The support is an ordered mesoporous metal oxide, the metal oxide being selected from at least one of CeO2, CeO2-MgO, CeO2-La2O3, and CeO2-ZrO2. The noble metal component is Ru, and the non-noble metal component is at least one of Group VIII non-noble metals. Based on the weight of the catalyst, the content of the noble metal component is 0.1-2% and the content of the non-noble metal component is 0.03-6% by elemental basis.

[0006] In one embodiment of the present invention, the noble metal component exists at least partially in a metallic state, and the metal particle size is 1–10 nm, preferably 1–3 nm. In this invention, the dispersion of the noble metal component is characterized by the metal particle size; the smaller the particle size, the higher the dispersion of the metal. In a preferred embodiment of the present invention, the noble metal component is entirely composed of metal particles.

[0007] In one embodiment of the present invention, the non-precious metal component is Ni.

[0008] In one embodiment of the present invention, based on the weight of the catalyst, the content of the noble metal component is 0.5-2% and the content of the non-noble metal component is 0.5-4% in terms of elemental composition.

[0009] In this invention, the noble metal component and the non-noble metal component have a synergistic effect. Under optimal conditions, this promotes intermetallic interactions and increases the phthalate conversion rate. However, excessively high levels of the non-noble metal component may lead to an increase in byproducts.

[0010] In this invention, the content of each component is obtained by X-ray fluorescence spectroscopy (XRF) testing.

[0011] In this invention, the catalyst support is a metal oxide with an ordered mesoporous structure. The ordered mesoporous structure of the support enhances the interaction between the support and the catalyst, promotes high dispersion of the active phase, and effectively improves the diffusion efficiency of the reactants.

[0012] In a preferred embodiment of the present invention, the metal oxide is a composite metal oxide, which can provide different active sites, thus improving the selectivity of the target product. The composite metal oxide is at least one selected from CeO2-MgO, CeO2-La2O3, and CeO2-ZrO2.

[0013] In one embodiment of the present invention, after the carrier is molded, it is loaded with precious metal components and non-precious metal components. The shape of the molded carrier is one or more of the following: nest shape, hollow clover shape, and Raschig ring shape. The equivalent diameter of the nest shape is 2-5 mm, and the nest shape refers to the honeycomb shape. The cross-section of the hollow clover shape is clover-shaped, and its circumscribed circle diameter is 1-3 mm. The inner diameter of the hollow shape is 1 / 12 to 1 / 8 of the circumscribed circle diameter. The equivalent diameter of the Raschig ring shape is 3-5 mm.

[0014] According to the present invention, the catalyst optimizes the interaction between the support and the catalyst, and has the characteristics of promoting high dispersion of the active phase and improving the diffusion efficiency of reactants, thereby improving the selectivity of the catalyst for cyclohexanedicarboxylate.

[0015] A second aspect of the present invention provides a method for preparing any of the above-mentioned catalysts for the selective hydrogenation of phthalates, the method comprising:

[0016] (1) After uniformly mixing the precursor salt of the metal oxide with the template agent, a first calcination is performed to obtain the first solid;

[0017] (2a) The first solid is etched in an alkaline solution, and after filtration, washing and drying, a second solid is obtained. The second solid is a metal oxide with an ordered mesoporous structure.

[0018] (3) Mix solution A containing precious metal components, solution B containing non-precious metal components, and surfactant to obtain a mixture;

[0019] (4) The mixture is mixed with an ordered mesoporous metal oxide, and after deposition, rotary drying and second calcination, a catalyst precursor is obtained;

[0020] (5) The catalyst precursor is reduced and activated to obtain the catalyst.

[0021] In one embodiment of the present invention, in step (1), the precursor salt of the metal oxide is a nitrate; the template agent is selected from at least one of KIT-6 and SBA-15;

[0022] The mass ratio of the precursor salt of the metal oxide to the template agent is 1:0.5 to 1:3, preferably 1:1 to 1:2.

[0023] In one embodiment of the present invention, the temperature of the first roasting is 400-600°C, and the time of the first roasting is 2-8 hours.

[0024] In one embodiment of the present invention, in step (2a), the alkaline solution is a NaOH solution with a concentration of 1 to 5 mol / L.

[0025] In one embodiment of the present invention, the present invention further includes step (2b): (2b) molding the ordered mesoporous metal oxide to obtain the molded carrier;

[0026] In step (4), the mixture is mixed with the shaped support, and after deposition, rotary drying and second calcination, a catalyst precursor is obtained.

[0027] In one embodiment of the present invention, in step (2b), the ordered mesoporous metal oxide is mixed evenly with an aluminum-containing binder and optionally a pore-forming agent, kneaded with an aqueous nitric acid solution, and then extruded, dried and calcined to obtain the shaped carrier.

[0028] The aluminum-containing binder is selected from at least one of boehmite, aluminum silicate, aluminum phosphate, and bentonite.

[0029] The pore-forming agent is selected from at least one of guar gum powder, cellulose, carboxymethyl cellulose, and bentonite.

[0030] In one embodiment of the present invention, the temperature of the third roasting is 500-600°C, and the time of the third roasting is 2-24 hours.

[0031] In one embodiment of the present invention, in step (3), the solute in solution A is a soluble ruthenium salt, selected from at least one of ruthenium acetate and nitrosyl ruthenium nitrate;

[0032] The solute in solution B is a soluble non-precious metal salt, selected from at least one of carbonates and nitrates;

[0033] In a preferred embodiment of the present invention, the solute in solution B is a soluble nickel salt.

[0034] According to the present invention, solutions A and B each independently include a solvent. The present invention does not particularly limit the specific type of solvent; conventional solvents in the art can be used, for example, water. The present invention also does not impose any particular requirement on the amount of solvent used, as long as it is sufficient to fully dissolve the desired substance. Those skilled in the art can select the appropriate amount based on actual needs.

[0035] In one embodiment of the present invention, the pH of the mixture of solution A and solution B is adjusted by introducing an inorganic base, preferably ammonia.

[0036] The surfactant is selected from at least one of P123, P105, and F127 triblock copolymer surfactants, and the molar ratio of the amount of surfactant to the total amount of Ru source (in elemental terms) is 0.2 to 10:1, preferably 1 to 2:1.

[0037] In step (4) of this invention, the selection range for the specific deposition conditions is relatively wide. In one embodiment of this invention, the conditions for the stirred deposition include: a reaction temperature of 30–60°C, preferably 40–50°C, and a reaction time of 0.5–4 h, preferably 1–2 h. In this invention, the deposition is carried out under stirred conditions. This invention does not have any special requirements for the specific stirred conditions, and conventional operating conditions in the art can be used.

[0038] In one embodiment of the present invention, the deposited product is dried by rotary evaporation and then calcined. The present invention does not particularly limit the rotary evaporation drying method and conditions, and those skilled in the art can select them according to actual needs. Preferably, the drying conditions include rotary evaporation drying at 40–80°C for 6–12 hours.

[0039] In one embodiment of the present invention, the conditions for the second calcination include: the temperature of the second calcination is 350-600°C, preferably 450-550°C, and the time of the second calcination is 10-48 hours, preferably 12-24 hours.

[0040] In step (5) of this invention, the catalyst precursor undergoes reduction activation, causing Ru to exist in a metallic state. In one embodiment of this invention, the reduction activation conditions include: a reduction temperature of 150–350°C, preferably 200–250°C, a time of 5–20 h, preferably 8–12 h, and a volume hourly space velocity (VHSV) of 200–4000 h⁻¹. -1 The reducing gas is a mixture of H2 and N2, with an H2 content of 10-30% by volume.

[0041] A third aspect of the present invention provides the application of any of the above-mentioned catalysts for the selective hydrogenation of phthalates, comprising: loading the catalyst into a fixed-bed reactor; and, under conditions for the selective hydrogenation of phthalates, reacting phthalates and hydrogen together with the catalyst in the fixed-bed reactor to generate a product including cyclohexanedicarboxylate, wherein the conditions for the selective hydrogenation of phthalates include: a reaction temperature of 100–200°C, a reaction pressure of 3–8 MPa, and a liquid hourly space velocity of 0.1–3 h⁻¹. -1 The hydrogen-to-liquid ratio is 200-800. Preferably, the selective hydrogenation reaction conditions for the phthalate ester include: a reaction temperature of 120-160°C, a reaction pressure of 5-7 MPa, and a liquid hourly space velocity of 0.2-1 h⁻¹. -1 The hydrogen-to-liquid ratio is 400–600.

[0042] This invention provides a catalyst for the selective hydrogenation of phthalates. The catalyst support is a metal oxide with an ordered mesoporous structure. The ordered mesoporous structure of the support enhances the interaction between the support and the catalyst, promoting high dispersion of the active phase while effectively improving the diffusion efficiency of the reactants, thus increasing the selectivity of the catalyst for cyclohexanedicarboxylate. The catalyst of this invention, when used in the selective hydrogenation reaction of phthalates, enables a continuous reaction process while improving product yield. Detailed Implementation

[0043] The present invention will be further described below with reference to embodiments, but the present invention shall not be limited thereto.

[0044] In the following examples and comparative examples, the content of each component of the catalyst was obtained by X-ray fluorescence spectroscopy (XRF). The specific surface area of ​​the catalyst was measured according to the method described in GB / T 5816. The particle size of the catalyst metal particles was obtained by CO pulse chemisorption testing using an AutoChem 2920 adsorbent analyzer manufactured by Micromeritics, USA.

[0045] Example 1

[0046] (1) Preparation of metal oxides

[0047] 4.3 g of cerium nitrate hexahydrate and 3.9 g of lanthanum nitrate pentahydrate (molar ratio Ce:La = 1:1) were uniformly mixed in a mortar. Then, the mixed nitrates and 10.0 g of KIT-6 template agent were further mixed and thoroughly ground in an agate mortar until the color was uniform. The mixture was then calcined in a muffle furnace at a rate of 1 °C / min from room temperature to 600 °C for 5 h. The calcined solid was poured into 100 mL of 2 mol / L NaOH solution and stirred vigorously for 20 min. After filtration, washing, and drying, an ordered mesoporous metal oxide, CeO2-La2O3, was obtained.

[0048] (2) Molding process

[0049] Boehmite, ordered mesoporous metal oxide CeO2-La2O3 powder, and guar gum powder were added to a kneader and mixed evenly. Then, an aqueous solution of nitric acid (2.0% of the mass of boehmite) was added and kneaded. The mixture was then extruded using a vertical hydraulic extruder. The perforated plate was nest-shaped with an equivalent diameter of about 3-4 mm. The carrier length was controlled to be 4-5 mm, and the nest-shaped skeleton thickness was about 0.35 mm. The formed carrier was first dried in an oven at 60-150℃ for 8-16 h, and then heated to 600℃ at a heating rate of 50℃ / h for 3 h to obtain the formed carrier CeO2-La2O3.

[0050] (3) Catalyst preparation

[0051] Aqueous solutions of nitrosylruthenium nitrate (solution A) and nickel nitrate (solution B) were prepared by saturated impregnation. After thorough mixing of solutions A and B, the pH of the solution was adjusted to 0.5 using 10% ammonia. P123 surfactant was added to the mixture at a 1:1 molar ratio of surfactant to Ru, and the mixture was stirred thoroughly. The mixture was then thoroughly mixed with the formed support and deposited at 40°C with thorough stirring for 2 hours. Afterward, it was rotary dried at 50°C, 20 rpm, and -0.1 MPa for 40 minutes, and then dried again at 120°C for 5 hours. Finally, it was calcined at 500°C in air for 5 hours to obtain the catalyst precursor.

[0052] The catalyst precursor was activated by reduction, with a reducing gas composition of 10% H2 / N2 and a reducing gas space velocity of 1000 h⁻¹. -1 The reduction temperature was 200℃ and the reduction time was 8 hours to obtain a selective hydrogenation catalyst for phthalic acid esters, denoted as catalyst S-1.

[0053] The physicochemical properties of the catalysts are shown in Table 1. In catalyst S-1, the Ru content is 0.97 wt% and the Ni content is 0.95 wt% based on the catalyst weight.

[0054] Example 2

[0055] (1) Preparation of metal oxides

[0056] 10.0 g of cerium nitrate hexahydrate and 10.0 g of KIT-6 template agent were further mixed and thoroughly ground in an agate mortar until the color was uniform. The mixture was then calcined in a muffle furnace at a rate of 1 °C / min from room temperature to 600 °C for 5 h. The calcined solid was poured into 100 mL of 2 mol / L NaOH solution and stirred vigorously for 20 min. After filtration, washing, and drying, an ordered mesoporous metal oxide CeO2 was obtained.

[0057] Catalyst S-2 was obtained according to the preparation method in steps (2) and (3) of Example 1.

[0058] The physicochemical properties of the catalysts are shown in Table 1. Specifically, in catalyst S-2, the Ru content is 0.97 wt% and the Ni content is 0.96 wt% based on the catalyst weight.

[0059] Example 3

[0060] The carrier was prepared according to steps (1) and (2) in Example 1.

[0061] The catalyst was prepared according to step (3) in Example 1 to obtain catalyst S-3, except that the Ni loading was different.

[0062] The physicochemical properties of the catalysts are shown in Table 1. Among them, catalyst S-3, based on the weight of the catalyst, has a Ru content of 1.01 wt% and a Ni content of 5.14 wt%.

[0063] Example 4

[0064] The carrier was prepared according to steps (1) and (2) in Example 1.

[0065] The catalyst was prepared according to step (3) in Example 1, except that P123 surfactant was not added in step (3), thus obtaining catalyst S-4.

[0066] The physicochemical properties of the catalysts are shown in Table 1. Specifically, in catalyst S-4, the Ru content is 0.98 wt% and the Ni content is 0.95 wt% based on the catalyst weight.

[0067] Example 5

[0068] Catalyst S-5 was prepared according to the method in Example 1. The difference is that in step (2), a vertical hydraulic extruder was used for extrusion. The perforated plate was hollow clover-shaped. The cross-section of the hollow clover-shaped plate was clover-shaped. Its outer circle diameter was 1.8 mm. The inner diameter of the hollow plate was 1 / 12 of the outer circle diameter. The length of the carrier was controlled to be 4-5 mm.

[0069] The physicochemical properties of the catalysts are shown in Table 1. Specifically, in catalyst S-5, the Ru content is 0.98 wt% and the Ni content is 0.97 wt% based on the catalyst weight.

[0070] Example 6

[0071] The carrier was prepared according to steps (1) and (2) in Example 1. The difference was that in step (1), the molar ratio was kept constant, and zirconium nitrate pentahydrate was used instead of lanthanum nitrate pentahydrate to obtain an ordered mesoporous metal oxide CeO2-ZrO2.

[0072] The catalyst was prepared according to step (3) in Example 1 to obtain catalyst S-6.

[0073] The physicochemical properties of the catalysts are shown in Table 1. Specifically, in catalyst S-6, the Ru content is 0.97 wt% and the Ni content is 0.95 wt% based on the catalyst weight.

[0074] Comparative Example 1

[0075] Catalyst DS-1 was prepared according to the method in Example 1. The difference is that KIT-6 template agent was not added during the metal oxide synthesis process in step (1).

[0076] The physicochemical properties of the catalysts are shown in Table 1. Specifically, in catalyst DS-1, the Ru content is 0.96 wt% and the Ni content is 1.02 wt% based on the catalyst weight.

[0077] Comparative Example 2

[0078] Catalyst DS-2 was prepared according to the method in Example 1. The difference is that NaOH alkaline etching was not performed during the metal oxide synthesis process in step (1).

[0079] The physicochemical properties of the catalysts are shown in Table 1. Specifically, in catalyst DS-2, the Ru content is 0.98 wt% and the Ni content is 1.01 wt% based on the catalyst weight.

[0080] Comparative Example 3

[0081] The catalyst support was γ-Al₂O₃, and the rest were prepared according to the method in Example 1, resulting in catalyst DS-3.

[0082] The physicochemical properties of the catalysts are shown in Table 1. Specifically, in catalyst DS-3, the Ru content is 1.01 wt% and the Ni content is 1.02 wt% based on the catalyst weight.

[0083] Comparative Example 4

[0084] The catalyst DS-4 was prepared according to the method in Example 1, except that solution B was not added in step (3), that is, the metal component Ni was not added.

[0085] The physicochemical properties of the catalysts are shown in Table 1. In catalyst DS-4, the Ru content is 1.02 wt% (based on the weight of the catalyst).

[0086] Comparative Example 5

[0087] Catalyst DS-5 was prepared according to the method in Example 1. The difference is that in step (2), the orifice plate is clover-shaped with an outer circle diameter of 1.8 mm and the length of the support is controlled to be 4-5 mm.

[0088] The physicochemical properties of the catalysts are shown in Table 1. Specifically, in catalyst DS-5, the Ru content is 1.02 wt% and the Ni content is 0.97 wt% based on the catalyst weight.

[0089] Table 1

[0090]

[0091]

[0092] Application Examples

[0093] The catalysts used in the above examples and comparative examples were applied to the hydrogenation reaction of phthalates in a pressurized fixed-bed continuous flow reactor. The reaction was carried out at a catalyst loading of 20 mL, and the reduced catalyst was directly switched to the reaction conditions. The raw material was a 20 wt% dioctyl phthalate (DOP) solution with isooctyl alcohol as solvent. The reaction temperature was 140 °C, the reaction pressure was 5 MPa, and the reaction time space velocity was 10.0 h⁻¹. -1 The hydrogen-to-liquid ratio is 500.

[0094] The product was analyzed by a 7890 chromatogram with an FID detector using the internal standard method.

[0095] The specific reaction results are shown in Table 2. The data in Table 2 are calculated using the following formula.

[0096]

[0097] Where m 原料 ω represents the cumulative value of the raw material mass flow rate per unit time. 原料DOP m is the mass fraction of DOP in the raw material. 产品 ω represents the cumulative value of product quality collected per unit of time. 产品DOP ω represents the mass fraction of DOP in the product. 产品H6-DOP This refers to the mass fraction of cyclohexanedicarboxylate (H6-DOP) in the product.

[0098] Table 2

[0099] Catalyst number DOP conversion rate (%) H6-DOP selectivity (%) S-1 99.8 99.4 S-2 95.3 98.2 S-3 99.8 95.3 S-4 98.3 88.4 S-5 98.6 97.8 S-6 99.8 99.6 DS-1 65.2 70.1 DS-2 70.2 95.4 DS-3 60.2 68.5 DS-4 98.3 88.4 DS-5 88.4 98.4

[0100] As can be seen from the results in Tables 1 and 2, the noble metal component in catalyst S-1 prepared in Example 1 of this invention has a high degree of dispersion and exhibits the highest conversion rate and selectivity for cyclohexanedicarboxylate in the hydrogenation reaction of phthalate.

[0101] A comparison of Examples 1 and 2 shows that using composite ordered mesoporous metal oxides can further improve the interaction between active phases, thereby exhibiting a higher yield of the target product.

[0102] The comparison of Examples 1, 3, and 4 shows that the non-precious metal component Ni can effectively improve the active phase and selectivity of the catalyst, but excessive Ni will cause further decomposition of cyclohexanedicarboxylate and reduce the yield of the target product.

[0103] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst for the selective hydrogenation of phthalates, characterized in that, The catalyst comprises a support and a noble metal component and a non-noble metal component supported on the support. The support is an ordered mesoporous metal oxide selected from at least one of CeO2, CeO2-MgO, CeO2-La2O3, and CeO2-ZrO2. The noble metal component is Ru, and the non-noble metal component is at least one of Group VIII non-noble metals. Based on the weight of the catalyst, the content of the noble metal component is 0.1-2% and the content of the non-noble metal component is 0.03-6% by element.

2. The catalyst according to claim 1, characterized in that, The noble metal component exists at least partially in a metallic state, and the metal particle size is 1 to 10 nm, preferably 1 to 3 nm.

3. The catalyst according to claim 1, characterized in that, The non-precious metal component is Ni.

4. The catalyst according to claim 1, characterized in that, The metal oxide is selected from at least one of CeO2-MgO, CeO2-La2O3 and CeO2-ZrO2; Based on the weight of the catalyst, the content of precious metal components is 0.5-2% and the content of non-precious metal components is 0.5-4% by element.

5. The catalyst according to claim 1, characterized in that, After the carrier undergoes molding, it is loaded with precious metal components and non-precious metal components. The shaped carrier after molding is one or more of the following: nest-shaped, hollow clover-shaped, and Raschig ring-shaped. The equivalent diameter of the nest-shaped carrier is 2-5 mm, and the nest-shaped carrier refers to the honeycomb shape. The cross-section of the hollow clover-shaped carrier is clover-shaped, and its circumscribed circle diameter is 1-3 mm. The inner diameter of the hollow carrier is 1 / 12 to 1 / 8 of the circumscribed circle diameter. The equivalent diameter of the Raschig ring-shaped carrier is 3-5 mm.

6. A method for preparing a catalyst for the selective hydrogenation of phthalates according to any one of claims 1-5, comprising: (1) After uniformly mixing the precursor salt of the metal oxide with the template agent, a first calcination is performed to obtain the first solid; (2a) The first solid is etched in an alkaline solution, and after filtration, washing and drying, a second solid is obtained. The second solid is a metal oxide with an ordered mesoporous structure. (3) Mix solution A containing precious metal components, solution B containing non-precious metal components, and surfactant to obtain a mixture; (4) The mixture is mixed with an ordered mesoporous metal oxide, and after deposition, rotary drying and second calcination, a catalyst precursor is obtained; (5) The catalyst precursor is reduced and activated to obtain the catalyst.

7. The method according to claim 6, characterized in that, It also includes step (2b): (2b) The ordered mesoporous metal oxide is molded to obtain the molded carrier; In step (4), the mixture is mixed with the shaped support, and after deposition, rotary drying and second calcination, a catalyst precursor is obtained.

8. The method according to claim 6, characterized in that, In step (1), the precursor salt of the metal oxide is a nitrate; the template agent is selected from at least one of KIT-6 and SBA-15; The mass ratio of the precursor salt of the metal oxide to the template agent is 1:0.5 to 1:3, preferably 1:1 to 1:2; The temperature of the first roasting is 400-600℃, and the roasting time is 2-8 hours.

9. The method according to claim 6, characterized in that, In step (2a), the alkaline solution is a NaOH solution with a concentration of 1–5 mol / L.

10. The method according to claim 6, characterized in that, In step (3), the solute in solution A is a soluble ruthenium salt, selected from at least one of ruthenium acetate and ruthenium nitrite; The solute in solution B is a soluble non-precious metal salt, selected from at least one of carbonates and nitrates; The surfactant is at least one selected from P123, P105, and F127 triblock copolymer nonionic surfactants, and the molar ratio of the amount of surfactant to the total amount of Ru source (in elemental terms) is 0.2 to 10:1, preferably 1 to 2:

1.

11. The method according to claim 6, characterized in that, In step (4), the conditions for stirring and deposition include: a temperature of 30–60°C and a time of 0.5–4 h; The drying conditions include: rotary drying at 40–80°C for 6–12 hours; The second roasting temperature is 350–600℃, and the second roasting time is 10–48 hours.

12. The method according to claim 6, characterized in that, In step (5), the conditions for reduction activation include: a reduction temperature of 150–350°C, a time of 5–20 h, and a volume hourly space velocity (VHSV) of 200–4000 h⁻¹. -1 The reducing gas is a mixture of H2 and N2, with an H2 content of 10-30% by volume.

13. The method according to claim 7, characterized in that, In step (2b), the ordered mesoporous metal oxide is mixed evenly with an aluminum-containing binder and optionally a pore-forming agent, kneaded with an aqueous nitric acid solution, extruded, dried and calcined a third time to obtain the shaped carrier; The aluminum-containing binder is selected from at least one of boehmite, aluminum silicate, aluminum phosphate, and bentonite. The pore-forming agent is selected from at least one of guar gum powder, cellulose, carboxymethyl cellulose, and bentonite; The temperature of the third roasting is 500-600℃, and the roasting time is 2-24 hours.

14. The application of any one of the catalysts for the selective hydrogenation of phthalates according to claims 1-5, comprising: loading the catalyst into a fixed-bed reactor; and, under conditions for the selective hydrogenation of phthalates, reacting phthalates and hydrogen together with the catalyst in the fixed-bed reactor to generate a product including cyclohexanedicarboxylate, wherein the conditions for the selective hydrogenation of phthalates include: The reaction temperature is 100–200℃, the reaction pressure is 3–8 MPa, and the liquid hourly space velocity is 0.1–3 h⁻¹. -1 The hydrogen-to-liquid volume ratio is 200–800; Preferably, the reaction temperature is 120–160°C, the reaction pressure is 5–7 MPa, and the liquid hourly space velocity is 0.2–1 h⁻¹. -1 The hydrogen-liquid volume ratio is 400–600.

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