Precious metal catalyst for preparing dihydrodicyclopentadiene, method for preparing the same, and method for preparing dihydrodicyclopentadiene

Abstract

This invention relates to a noble metal catalyst for preparing dihydrodicyclopentadiene and its preparation method, as well as a method for preparing dihydrodicyclopentadiene. The noble metal catalyst contains a support and an active component. The support is one or more of titanium dioxide, cerium dioxide, silicon dioxide, aluminum oxide, and activated carbon. The active component contains one or more of palladium and platinum. Based on the dry weight of the noble metal catalyst, the content of the active component is 0.3% by weight or more. The particle size range of the active component is D ± a, where D is 5-13 nm and a is 1-4.2 nm. The catalyst of this invention exhibits high reactivity and high selectivity for dihydrodicyclopentadiene.

Description

Technical Field

[0001] This application relates to a noble metal catalyst for the preparation of dihydrodicyclopentadiene and a method for preparing dihydrodicyclopentadiene. Background Technology

[0002] With the increasing scale of ethylene and petroleum catalytic cracking units, C5 fraction resources are becoming increasingly abundant. Dicyclopentadiene (DCPD), as a major component of C5 fraction, is of great significance for efficient utilization. DCPD is a cyclic hydrocarbon containing two unsaturated bonds. Its semi-hydrogenation product, bridged dihydrodicyclopentadiene (Endo-DHDCPD), can be synthesized into other chemicals, such as tetrahydrotricyclopentadiene high-density fuel, via the Diels-Alder reaction. It can also be further hydrogenated to obtain bridged tetrahydrodicyclopentadiene (Endo-THDCPD, a major component of JP-10 fuel), which is an important fine chemical, pharmaceutical intermediate, and materials intermediate.

[0003] Currently, the Raney Ni catalyst, which is already in industrial application, exhibits high activity in DCPD hydrogenation. However, this catalyst is highly reactive, flammable, explosive, and difficult to store. Therefore, highly active supported catalysts have attracted widespread attention.

[0004] CN 111662150 A discloses a method for preparing bridged dihydrodicyclopentadiene by hydrogenation of dicyclopentadiene. In the presence of a hydrogenation catalyst, a hydrogen-donating reagent is used to lightly hydrogenate dicyclopentadiene into bridged dihydrodicyclopentadiene. Summary of the Invention

[0005] The purpose of this invention is to provide a noble metal catalyst for the preparation of dihydrodicyclopentadiene and its preparation method. The noble metal catalyst of this invention has high reactivity and high selectivity for dihydrodicyclopentadiene.

[0006] To achieve the above objectives, the present invention provides a noble metal catalyst for preparing dihydrodicyclopentadiene, wherein the noble metal catalyst comprises a support and an active component, wherein the support is one or more of titanium dioxide, cerium dioxide, silicon dioxide, aluminum oxide and activated carbon, and the active component comprises one or more of palladium and platinum; the content of the active component is 0.3% by weight or more based on the dry weight of the noble metal catalyst; the particle size range of the active component is D±a, wherein D is 5-13 nm and a is 1-4.2 nm.

[0007] Optionally, the carrier is titanium dioxide, the active component is palladium, the content of the active component is 0.3-2% by weight, and the active component is calculated as a metal element.

[0008] Optionally, D is 5-10nm and a is 1-4nm.

[0009] The second aspect of the present invention provides a method for preparing the noble metal catalyst provided in the first aspect of the present invention, the method comprising: mixing and grinding a noble metal precursor with a support, and subjecting the resulting mixture to heat treatment.

[0010] Optionally, the noble metal precursor is selected from one or more of organic palladium salts, inorganic palladium salts, organic platinum salts, and inorganic platinum salts;

[0011] Preferably, the noble metal precursor is selected from one or more of palladium acetylacetonate, palladium acetate, palladium chloride, palladium nitrate, platinum acetylacetonate, platinum acetate, platinum chloride, and platinum nitrate.

[0012] Optionally, the mixing and grinding time is 1-30 min, preferably 5-20 min.

[0013] Optionally, the heat treatment conditions include: a temperature of 350-1000℃, a time of 1.5-5h, and an atmosphere of one or more of air, nitrogen, hydrogen, and a hydrogen-nitrogen mixture.

[0014] A third aspect of the present invention provides a method for preparing dihydrodicyclopentadiene, the method comprising: hydrogenating dicyclopentadiene in the presence of a noble metal catalyst and a solvent to prepare dihydrodicyclopentadiene; wherein the noble metal catalyst is the noble metal catalyst provided in the first aspect of the present invention.

[0015] Optionally, the conditions for the hydrogenation reaction include: a reaction temperature of 10-30℃, a hydrogen pressure of 2-8MPa, a reaction time of 1-24h, and a stirring speed of 400-1000r / min.

[0016] Optionally, the weight ratio of the noble metal catalyst to dicyclopentadiene is 1:(1-20); the weight ratio of the solvent to dicyclopentadiene is 1:(10-30); and the solvent is selected from one or more of methylcyclohexane, benzene, toluene, and cyclohexane.

[0017] Through the above technical solution, the active component nanoparticles of the noble metal catalyst of the present invention are supported on a support, which have excellent catalytic hydrogenation reaction and selectivity for dihydrodicyclopentadiene.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is the XRD pattern of the noble metal catalyst prepared in Example 1 of this invention.

[0021] Figure 2 This is a TEM image of the noble metal catalyst prepared in Example 1 of this invention. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] The first aspect of this invention provides a noble metal catalyst for preparing dihydrodicyclopentadiene, the noble metal catalyst comprising a support and an active component, wherein the support is one or more selected from titanium dioxide, cerium dioxide, silicon dioxide, aluminum oxide and activated carbon, and the active component comprises one or more selected from palladium and platinum; the content of the active component is 0.3% by weight or more based on the dry weight of the noble metal catalyst; the particle size range of the active component is D±a, wherein D is 5-13 nm and a is 1-4.2 nm.

[0024] The noble metal catalyst of the present invention has active components with specific nanoscale sizes, and the particle size distribution range of the active components is narrow and the aggregation is small. The noble metal catalyst has superior reactivity and selectivity for dihydrodicyclopentadiene.

[0025] In one specific embodiment, the carrier is titanium dioxide, the active component is palladium, and the content of the active component is 0.3-2% by weight, preferably 0.3-1% by weight, and the active component is calculated as a metal element.

[0026] According to the present invention, the active component in the noble metal catalyst is supported on a support as particles of a specific nanoscale size, and the particle size distribution range of the active component is narrow. In one specific embodiment, the particle size range of the active component is D±a, where D is 5-10 nm and a is 1-4 nm. In the present invention, the noble metal catalyst is analyzed by transmission electron microscopy (TEM), and 150 active component particles are randomly selected from the TEM image. The distance between the two points with the largest distance on each of the 150 active component particles is measured, and the average distance is calculated to obtain D. The standard deviation of the distance is calculated to obtain a. The particle size range of the active component is expressed as D±a.

[0027] The second aspect of the present invention provides a method for preparing the noble metal catalyst provided in the first aspect of the present invention, the method comprising: mixing and grinding a noble metal precursor with a support, and subjecting the resulting mixture to heat treatment.

[0028] This invention is the first to employ a method of mixing and grinding a noble metal precursor with a support followed by heat treatment to prepare a noble metal catalyst. This method is simple and easy to operate. Furthermore, the inventors discovered that traditional impregnation methods, where the active component is loaded onto the support, may experience uneven deposition of the noble metal active component due to uneven stirring of the impregnation solution during the impregnation process. This results in uneven concentration of the impregnation solution, leading to relatively large differences in the particle size of the active component on the impregnated catalyst. In contrast, thorough mechanical grinding ensures more complete and uniform contact between the noble metal precursor and the support. The catalyst prepared using the method of this invention exhibits excellent hydrogenation performance, and the narrow particle size distribution of the active component provides good selectivity for dihydrodicyclopentadiene.

[0029] In one specific embodiment, the noble metal precursor is selected from one or more of organopalladium salts, inorganic palladium salts, organopallaminar salts, and inorganic platinum salts; preferably, the noble metal precursor is selected from one or more of palladium acetylacetonate, palladium acetate, palladium chloride, palladium nitrate, platinum acetylacetonate, platinum acetate, platinum chloride, and platinum nitrate. More preferably, the noble metal precursor is selected from one or more of palladium acetylacetonate, palladium acetate, platinum acetylacetonate, and platinum acetate. The metal precursor used in the preparation of the noble metal catalyst of this invention is an organometallic salt precursor. After decomposition through the heat treatment step of the preparation process, only the metal is retained on the support, without introducing impurities such as chlorine from inorganic metal salts. This results in the prepared noble metal catalyst having superior reactivity and selectivity for dihydrodicyclopentadiene.

[0030] According to the present invention, the mixing and grinding time can vary within a wide range. In a preferred embodiment, the mixing and grinding time is 1-30 minutes, more preferably 3-20 minutes, and even more preferably 5-20 minutes. The grinding can be performed using equipment well known to those skilled in the art, such as a mortar and pestle.

[0031] In one specific embodiment, the heat treatment conditions include: a temperature of 350-1000℃, a time of 1.5-5 hours, and an atmosphere of one or more of air, nitrogen, hydrogen, and a hydrogen-nitrogen mixture; preferably, the temperature is 400-600℃ and the time is 1.5-4 hours. The heat treatment can be performed in equipment well known to those skilled in the art, such as a muffle furnace or a tube furnace, and this invention does not impose specific limitations on this.

[0032] In one specific embodiment, the product obtained from heat treatment is reduced in a hydrogen atmosphere to improve the conversion rate of the feedstock when using a noble metal catalyst to prepare dihydrodicyclopentadiene. The reduction conditions include a temperature of 100-300°C and a time of 1-3 hours.

[0033] A third aspect of this invention provides a method for preparing dihydrodicyclopentadiene, the method comprising: hydrogenating dicyclopentadiene in the presence of a noble metal catalyst and a solvent to prepare dihydrodicyclopentadiene; wherein the noble metal catalyst is the noble metal catalyst provided in the first aspect of this invention. The method of this invention exhibits high selectivity for dihydrodicyclopentadiene.

[0034] In one specific embodiment of the present invention, the conditions for the hydrogenation reaction include: a reaction temperature of 10-30°C, a hydrogen pressure of 2-8 MPa, a reaction time of 1-24 h, and a stirring speed of 400-1000 r / min; preferably, the reaction temperature is 10-20°C, the hydrogen pressure is 3-5 MPa, the reaction time is 1-10 h, and the stirring speed is 450-800 r / min.

[0035] According to the present invention, the weight ratio of the noble metal catalyst to dicyclopentadiene can vary within a wide range. In one specific embodiment of the present invention, the weight ratio of the noble metal catalyst to dicyclopentadiene is 1:(1-20), preferably 1:(1-10); the weight ratio of the solvent to dicyclopentadiene is 1:(10-30), preferably 1:(10-20); the solvent is selected from one or more of methylcyclohexane, benzene, toluene, and cyclohexane. Under the above conditions, the selectivity for dihydrodicyclopentadiene can be further improved.

[0036] The present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

[0037] Unless otherwise specified, all raw materials used in the embodiments and comparative examples of this invention were commercially available.

[0038] Examples 1-10 are examples of catalyst preparation, and Comparative Example 1 is a comparative example of catalyst preparation; Examples 11-21 are examples of preparation of dihydrodicyclopentadiene, and Comparative Example 2 is an example of preparation of dihydrodicyclopentadiene.

[0039] Example 1

[0040] Palladium acetylacetone was mixed with titanium dioxide (P25) and ground for 20 minutes, denoted as mixture A, wherein the mass fraction of Pd was 0.3% by weight. Mixture A was placed in a muffle furnace and calcined in air at a heat treatment temperature of 500°C for 2 hours to obtain Pd-supported noble metal catalyst A.

[0041] The composition and particle size of the active components of the noble metal catalysts are shown in Table 1, and the same applies below. The XRD patterns of the noble metal catalysts are shown in... Figure 1 As shown, its TEM image is as follows Figure 2 As shown, the XRD pattern shows only diffraction peaks of titanium dioxide (P25), indicating that the active metal particles in the catalyst do not show obvious aggregation.

[0042] Example 2

[0043] The noble metal catalyst B was prepared using the same method as in Example 1, except that the support was cerium dioxide, and the catalyst was calcined in a muffle furnace and then reduced with hydrogen in a tube furnace at 200°C for 1 hour.

[0044] Example 3

[0045] The noble metal catalyst C was prepared using the same method as in Example 1, except that the heat treatment temperature was 300°C, the heat treatment time was 1 hour, and the heat treatment atmosphere was air.

[0046] Example 4

[0047] The noble metal catalyst D was prepared using the same method as in Example 1, except that the grinding time was 3 minutes.

[0048] Example 5

[0049] The noble metal catalyst E was prepared using the same method as in Example 1, except that palladium acetylacetonate was mixed with titanium dioxide (P25) and ground for 20 minutes, which was denoted as mixture B, wherein the mass fraction of Pd was 2.3% by weight.

[0050] Example 6

[0051] The noble metal catalyst F was prepared using the same method as in Example 1, except that the support was silicon dioxide.

[0052] Example 7

[0053] The noble metal catalyst G was prepared using the same method as in Example 1, except that the support was γ-Al2O3.

[0054] Example 8

[0055] The noble metal catalyst H was prepared using the same method as in Example 1, except that the support was silicon dioxide, and the catalyst was calcined in a muffle furnace and then reduced with hydrogen in a tube furnace at 200°C for 1 hour.

[0056] Example 9

[0057] Noble metal catalyst I was prepared using the same method as in Example 1, except that the support was γ-Al2O3, and the catalyst was calcined in a muffle furnace and then reduced with hydrogen in a tube furnace at 200°C for 1 hour.

[0058] Example 10

[0059] The noble metal catalyst J was prepared using the same method as in Example 1, except that the catalyst was calcined in a muffle furnace and then reduced with hydrogen in a tube furnace at 200°C for 1 hour.

[0060] Comparative Example 1

[0061] The Pd / TiO2 catalyst DA was prepared by impregnation method, wherein the mass fraction of Pd was 0.3% by weight. The specific steps were as follows: titanium dioxide was impregnated with an equal volume of palladium nitrate solution, then dried and calcined in air at 500°C for 3 hours.

[0062] Examples 11-20

[0063] The noble metal catalysts prepared in Examples 1-10 were used to carry out the catalytic hydrogenation reaction of dicyclopentadiene in a high-pressure reactor. The solvent was methylcyclohexane, and the mass fraction of dicyclopentadiene was 5%. The mass ratio of noble metal catalyst to dicyclopentadiene was 1:10. The reaction temperature was 15°C, the hydrogen pressure was 3 MPa, the reaction time was 1 h, and the stirring speed was 450 r / min.

[0064] Example 21

[0065] The catalytic hydrogenation reaction of dicyclopentadiene was carried out using the same method as in Example 11, except that the reaction temperature was 35°C, the hydrogen pressure was 6 MPa, the reaction time was 12 h, and the stirring speed was 400 r / min.

[0066] Comparative Example 2

[0067] The noble metal catalyst prepared in Comparative Example 1 was subjected to catalytic hydrogenation of dicyclopentadiene in a high-pressure reactor. The solvent was methylcyclohexane, and the mass fraction of dicyclopentadiene was 5%. The mass ratio of the noble metal catalyst to dicyclopentadiene was 1:10. The reaction temperature was room temperature (about 15°C), the pressure was 3 MPa, the reaction time was 1 h, and the stirring speed was 450 r / min.

[0068] Table 1

[0069]

[0070] Table 2

[0071]

[0072]

[0073] As can be seen from the above, the noble metal catalyst of the present invention has superior hydrogenation reaction activity, and when used to prepare dihydrodicyclopentadiene from dicyclopentadiene, it exhibits high selectivity for dihydrodicyclopentadiene.

[0074] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0075] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0076] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing dihydrodicyclopentadiene, the method comprising: Dihydrodicyclopentadiene is prepared by hydrogenation of dicyclopentadiene in the presence of a noble metal catalyst and a solvent. The noble metal catalyst contains a support and an active component. The support is titanium dioxide and / or cerium dioxide, and the active component contains one or more of palladium and platinum. Based on the dry weight of the noble metal catalyst, the content of the active component is 0.3-2% by weight. The particle size range of the active component is D±a, where D is 5-10 nm and a is 1-4 nm. The noble metal catalyst was analyzed by transmission electron microscopy (TEM). 150 active component particles were randomly selected from the TEM images. The distance between the two points with the largest distance on each of the 150 active component particles was measured. The average distance was calculated to obtain D, and the standard deviation of the distance was calculated to obtain a. The particle size range of the active components was expressed as D±a. The noble metal catalyst is prepared by a method including the following steps: mixing and grinding a noble metal precursor with a support, and then heat-treating the resulting mixture. The heat treatment conditions include: a temperature of 400-600℃, a time of 1.5-4h, and an atmosphere of one or more of air, nitrogen, and hydrogen.

2. The method according to claim 1, wherein, The noble metal precursor is selected from one or more of organic palladium salts, inorganic palladium salts, organic platinum salts, and inorganic platinum salts.

3. The method according to claim 2, wherein, The noble metal precursor is selected from one or more of palladium acetylacetonate, palladium acetate, palladium chloride, palladium nitrate, platinum acetylacetonate, platinum acetate, platinum chloride, and platinum nitrate.

4. The method according to claim 1, wherein, The mixing and grinding time is 1-30 minutes.

5. The method according to claim 1, wherein, The mixing and grinding time is 5-20 minutes.

6. The method according to claim 1, wherein, The conditions for the hydrogenation reaction include: a reaction temperature of 10-30℃, a hydrogen pressure of 2-8MPa, a reaction time of 1-24h, and a stirring speed of 400-1000 r / min.

7. The method according to claim 1, wherein, The weight ratio of the noble metal catalyst to dicyclopentadiene is 1:(1-20); the weight ratio of the solvent to dicyclopentadiene is 1:(10-30); the solvent is selected from one or more of methylcyclohexane, benzene, toluene and cyclohexane.

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