A catalyst for preparing dihydrodicyclopentadiene, a method for preparing the same, and an application thereof
By using Ni and Fe single-atom catalysts with nitrogen-doped porous carbon supports in the preparation of dihydrodicyclopentadiene, the problems of easy aggregation of catalyst active components and high cost of precious metals were solved, and efficient preparation of dihydrodicyclopentadiene with high yield and selectivity was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2022-09-30
- Publication Date
- 2026-06-16
AI Technical Summary
Existing catalysts for the preparation of dihydrodicyclopentadiene suffer from problems such as easy aggregation of active components, high cost of precious metals, and low selectivity, making it difficult to achieve high yields of dihydrodicyclopentadiene.
A catalyst using nitrogen-doped porous carbon as a support and Ni and Fe single atoms as active components was prepared by a specific method to ensure the dispersion of active components and the mildness of reaction conditions. The catalyst was then used for hydrogenation reactions.
This study achieved high feed conversion rate, target product selectivity, and yield of dihydrodicyclopentadiene, avoiding the use of precious metals and the aggregation of active components, and providing an economical and efficient preparation method.
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Figure CN117839736B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the petrochemical field, specifically to a catalyst for the preparation of dihydrodicyclopentadiene, a method for its preparation, and its application. 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-THDCPD), 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 (a major component of JP-10 fuel), an important fine chemical, pharmaceutical intermediate, and materials intermediate.
[0003] Currently, industrial Raney Ni catalysts exhibit high DCPD hydrogenation activity, but they are highly reactive, flammable, explosive, and difficult to store. Therefore, highly active supported catalysts have attracted widespread attention. Precious metals such as Pd and Pt are often exhibiting good DCPD hydrogenation activity, but their high cost and limited availability restrict their application. Furthermore, the excessively high hydrogenation activity of precious metals often yields tetrahydrodicyclopentadiene, making it difficult to obtain high yields of dihydrodicyclopentadiene. Summary of the Invention
[0004] The purpose of this disclosure is to provide a catalyst for the preparation of dihydrodicyclopentadiene, a method for its preparation, and its application. This catalyst can achieve high feed conversion, target product selectivity, and yield when used to prepare dihydrodicyclopentadiene.
[0005] To achieve the above objectives, this disclosure provides a first aspect of a catalyst for preparing dihydrodicyclopentadiene, said catalyst comprising a support and an active component;
[0006] The active components include Ni single atoms and Fe single atoms, and the support is nitrogen-doped porous carbon.
[0007] Optionally, based on the total weight of the catalyst, the Ni content is 0.1-0.6% by weight and the Fe content is 0.6-1.7% by weight.
[0008] A second aspect of this disclosure provides a method for preparing a catalyst for dihydrodicyclopentadiene, the method comprising the following steps:
[0009] (1) The metal source and 2-methylimidazole were reacted in a solvent to obtain the precursor material;
[0010] (2) The precursor material is heat-treated in an inert atmosphere;
[0011] The metal sources include zinc, nickel, and iron.
[0012] Optionally, step (1) includes:
[0013] S1. The metal source is mixed with a portion of the solvent to obtain a first mixture;
[0014] S2. The 2-methylimidazole is mixed with another portion of the solvent to obtain a second mixture;
[0015] S3. Mix the first mixture and the second mixture to carry out the contact reaction.
[0016] Optionally, the volume ratio of one portion of the solvent to the other portion of the solvent is (1-20):1.
[0017] Optionally, the molar ratio of the metal source to the 2-methylimidazole, calculated as metal element, is 1:(5-20);
[0018] The total molar ratio of the nickel source (calculated as nickel) and the iron source (calculated as iron) to the zinc source (calculated as zinc) is 1:(1-12).
[0019] The molar ratio of the nickel source, calculated as nickel, to the iron source, calculated as iron, is (1-20):1.
[0020] Optionally, the zinc source includes one or more of zinc nitrate, zinc acetate, and zinc chloride;
[0021] The nickel source includes one or more of basic nickel carbonate, nickel nitrate, nickel sulfate, nickel chloride, and nickel acetate;
[0022] The iron source includes one or more of ferric nitrate, ferric sulfate, ferric chloride, ferrous nitrate, ferrous chloride, and ferrous sulfate;
[0023] The solvent includes one or more of methanol, ethanol, and water.
[0024] Optionally, in step (1), the contact reaction time is 20-40 hours.
[0025] Optionally, in step (2), the inert atmosphere includes one or more of nitrogen, argon, a hydrogen-nitrogen mixture, and a hydrogen-argon mixture;
[0026] The heat treatment conditions include: a time of 1.5-5 hours and a temperature of 850-1000℃.
[0027] The third aspect of this disclosure provides a catalyst prepared using the method described in the second aspect of this disclosure.
[0028] The fourth aspect of this disclosure provides a method for preparing dihydrodicyclopentadiene, the method comprising: contacting dicyclopentadiene, hydrogen gas and a catalyst to carry out a hydrogenation reaction, wherein the catalyst is the catalyst described in the first or third aspect of this disclosure.
[0029] Optionally, the conditions for the hydrogenation reaction include: a temperature of 110-200℃, a hydrogen pressure of 2-8MPa, a time of 8-24h, and a mass ratio of the catalyst to the dicyclopentadiene of 1:(4-12).
[0030] Through the above technical solution, the catalyst disclosed herein uses nitrogen-doped porous carbon as a support, which can ensure a good ion electron transport channel. Ni and Fe, which exist in the form of single atoms, are used as active components. When used to prepare dihydrodicyclopentadiene, it has the characteristics of mild reaction conditions, high raw material conversion rate, high dihydrodicyclopentadiene selectivity and high yield.
[0031] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description
[0032] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:
[0033] Figure 1 This is the XRD pattern of catalyst A1 prepared in Example 1 of this disclosure.
[0034] Figure 2 This is a STEM image of catalyst A1 prepared in Example 1 of this disclosure.
[0035] Figure 3 This is a TEM image of catalyst A1 prepared in Example 1 of this disclosure. Detailed Implementation
[0036] The specific embodiments of this disclosure 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 this disclosure.
[0037] The first aspect of this disclosure provides a catalyst for preparing dihydrodicyclopentadiene, the catalyst comprising a support and an active component;
[0038] The active components include Ni single atoms and Fe single atoms, and the support is nitrogen-doped porous carbon.
[0039] The catalyst disclosed herein uses nitrogen-doped porous carbon as a support, which can ensure good ion and electron transport. Ni and Fe, which exist in single-atom form, are used as active components, giving it excellent hydrogenation catalytic performance.
[0040] In this disclosure, the active components are distributed on the catalyst surface and optionally in the bulk phase of the catalyst. At least a portion of the Ni single atoms and Fe single atoms form covalent bonds with nitrogen and / or carbon in the support, respectively, resulting in high dispersion in the catalyst, which is beneficial for improving catalytic activity.
[0041] XRD analysis of the catalyst revealed only carbon diffraction peaks and no metal diffraction peaks, indicating that the active metal component did not show significant aggregation in the catalyst. STEM analysis showed no lattice fringes in the STEM image, indicating that the active metal component was not crystallized; however, the presence of single-atom bright spots in the STEM image indicated that the active metal component existed in a single-atom state.
[0042] According to one embodiment of this disclosure, based on the total weight of the catalyst, the content of Ni element is 0.1-0.6% by weight and the content of Fe element is 0.6-1.7% by weight; preferably, the content of Ni element is 0.2-0.5% by weight and the content of Fe element is 1-1.5% by weight. When the content of Ni element and Fe element meets the above ranges, the dispersion of Ni and Fe is high and the hydrogenation activity of the catalyst is good.
[0043] A second aspect of this disclosure provides a method for preparing a catalyst for dihydrodicyclopentadiene, the method comprising the following steps:
[0044] (1) The metal source and 2-methylimidazole were reacted in a solvent to obtain the precursor material;
[0045] (2) The precursor material is heat-treated in an inert atmosphere;
[0046] The metal sources include zinc, nickel, and iron.
[0047] In this disclosure, the addition of a zinc source can ensure that the content of Ni and Fe in the catalyst is within a suitable range, thus avoiding the aggregation of active components; the precursor material has a MOF structure, and during the heat treatment process, zinc and some non-metals volatilize to form a nitrogen-doped porous carbon support; metal ions are reduced by carbon to form a single-atom structure.
[0048] According to one embodiment of this disclosure, step (1) includes:
[0049] S1. Mix the metal source with a portion of the solvent to obtain the first mixture;
[0050] S2. Mix 2-methylimidazole with another portion of the solvent to obtain a second mixture;
[0051] S3. Mix the first mixture and the second mixture to carry out a contact reaction. The above operation can improve the dispersion of the metal source and 2-methylimidazole in the solvent, resulting in better catalytic performance of the prepared catalyst.
[0052] According to one embodiment of this disclosure, the volume ratio of one portion of the solvent to another portion of the solvent is (1-20):1.
[0053] According to one embodiment of this disclosure, the molar ratio of the metal source to 2-methylimidazole, calculated as metal element, is 1:(5-20), preferably 1:(8-15).
[0054] According to one embodiment of this disclosure, the total molar ratio of nickel source (calculated as nickel element) and iron source (calculated as iron element) to zinc source (calculated as zinc element) is 1:(1-12), preferably 1:(1-8); the above range can increase the content of metal active component in the catalyst while ensuring high dispersion of metal active component, so that the catalyst has better catalytic activity.
[0055] According to one embodiment of this disclosure, the molar ratio of nickel source (calculated as nickel element) to iron source (calculated as iron element) is (1-20):1, preferably (5-10):1. Within the above range, the dispersion of the metal active component in the prepared catalyst is better, and the catalytic activity is better.
[0056] According to one embodiment of this disclosure, the zinc source includes a soluble zinc salt, preferably one or more of zinc nitrate, zinc acetate, and zinc chloride; the nickel source includes a soluble nickel salt, preferably one or more of basic nickel carbonate, nickel nitrate, nickel sulfate, nickel chloride, and nickel acetate; the iron source includes a soluble iron salt and / or a soluble ferrous salt, preferably one or more of ferric nitrate, ferric sulfate, ferric chloride, ferrous nitrate, and ferrous sulfate, more preferably ferric nitrate and / or ferric chloride; the solvent includes water and one or more of saturated monohydric alcohols having 1-3 carbon atoms, preferably one or more of methanol, ethanol, and water.
[0057] According to one embodiment of this disclosure, in step (1), the contact reaction time is 20-40 hours, and there is no special limitation on the contact reaction temperature, for example, the temperature is 15-30°C.
[0058] According to one embodiment of the present disclosure, step (1) further includes: performing solid-liquid separation and drying on the solid-liquid mixture obtained from the contact reaction to obtain a precursor material, wherein the solid-liquid separation method is conventional in the art, such as centrifugal separation; the drying method and conditions are conventional in the art and will not be described in detail here.
[0059] According to one embodiment of this disclosure, in step (2), the inert atmosphere includes one or more of nitrogen, argon, a hydrogen-nitrogen mixture, and a hydrogen-argon mixture, preferably one or more of nitrogen, argon, and a hydrogen-nitrogen mixture; wherein the volume fraction of nitrogen in the hydrogen-nitrogen mixture is 95% by volume, and the volume fraction of argon in the hydrogen-argon mixture is 95% by volume.
[0060] According to one embodiment of this disclosure, in step (2), the heat treatment conditions include: a time of 1.5-5 hours, preferably 1.5-4 hours; and a temperature of 850-1000°C, preferably 850-950°C. Using these heat treatment conditions allows metal ions to be reduced, zinc to volatilize, forming the desired single-atom structure, and avoids the aggregation of active components caused by excessively high temperatures.
[0061] This disclosure provides a third aspect of a catalyst prepared using the method described in the second aspect of this disclosure. The catalyst described above has the same characteristics as the catalyst described in the first aspect of this disclosure, and will not be repeated here.
[0062] The fourth aspect of this disclosure provides a method for preparing dihydrodicyclopentadiene, the method comprising: contacting dicyclopentadiene, hydrogen gas and a catalyst to carry out a hydrogenation reaction, wherein the catalyst is the catalyst described in the first or third aspect of this disclosure.
[0063] According to one embodiment of this disclosure, the conditions for the hydrogenation reaction include: a temperature of 110-200°C, preferably 120-160°C; a hydrogen pressure of 2-8 MPa, preferably 3-6 MPa; a time of 8-24 h, preferably 12-24 h; and a mass ratio of catalyst to dicyclopentadiene of 1:(4-12), preferably 1:(4-8).
[0064] In one embodiment of this disclosure, the hydrogenation reaction is carried out in the presence of a solvent, the type and amount of which are conventional in the art, for example, methylcyclohexane and / or cyclohexane, wherein the mass fraction of dicyclopentadiene is 10% relative to the total weight of the solvent and dicyclopentadiene. Dicyclopentadiene is conventional in the art and is not subject to any special requirements.
[0065] In one embodiment of this disclosure, the hydrogenation reaction can be carried out in a high-pressure reactor with a stirring speed of 400-1000 r / min, preferably 400-800 r / min.
[0066] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way.
[0067] All raw materials used in the examples were obtained through commercial purchases and, unless otherwise specified, were of analytical grade.
[0068] XRD testing instruments and conditions: PANalytical diffractometer, Cu target, scanning range of 5-90°, scanning speed of 10° / min.
[0069] STEM testing instrument: FEI Talos F200X.
[0070] TEM testing instrument: JEM-2100.
[0071] Test methods and instruments for Ni and Fe content: Agilent ICPOES730, emission power 1.0KW.
[0072] In this disclosure, the conversion rate of dicyclopentadiene and the selectivity of dihydrodicyclopentadiene were calculated by gas chromatography using the peak area normalization method. The gas chromatograph used was an Agilent Gas Chromatograph 7890B.
[0073] Conversion rate = (percentage of 1-dicyclopentadiene peak area) × 100%
[0074]
[0075] Yield = Conversion Rate × Selectivity
[0076] Example 1
[0077] Catalyst A1 was prepared using the following steps, and dihydrodicyclopentadiene was then prepared.
[0078] (1) Zinc nitrate hexahydrate, nickel nitrate hexahydrate, ferric nitrate nonahydrate and a portion of methanol are mixed to obtain the first mixture;
[0079] (2) Mix 2-methylimidazole with another portion of methanol to obtain a second mixture;
[0080] (3) The first mixture and the second mixture are mixed and reacted for 24 hours at room temperature (25°C). Then the mixture is centrifuged and dried to obtain the precursor material.
[0081] (4) The precursor material was heat-treated in a tube furnace at 900℃ for 2 hours under a nitrogen atmosphere to obtain catalyst A1. Its parameters are listed in Table 1. XRD, STEM, and TEM tests were performed on catalyst A1, and the results are listed below. Figure 1 , 2 and 3;
[0082] In the first mixture, the concentration of metal ions is 0.0395 mol / L; in the second mixture, the concentration of 2-methylimidazole is 1.58 mol / L; the volume ratio of one part of methanol to another part of methanol is 5:1; and the molar ratio of the metal source to 2-methylimidazole, calculated as metal element, is 1:8.
[0083] The total molar ratio of nickel source (calculated as nickel element) and iron source (calculated as iron element) to zinc source (calculated as zinc element) is 1:8; the molar ratio of nickel source (calculated as nickel element) to iron source (calculated as iron element) is 5:1.
[0084] Catalyst A1 was 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 10%. The mass ratio of catalyst to dicyclopentadiene was 3:20. The reaction temperature was 140℃, the hydrogen pressure was 3MPa, the reaction time was 4h, and the stirring speed was 700r / min. The reaction results are listed in Table 1.
[0085] Example 2
[0086] Catalyst A1 was 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 10%. The mass ratio of catalyst to dicyclopentadiene was 3:20. The reaction temperature was 120℃, the hydrogen pressure was 3MPa, the reaction time was 8h, and the stirring speed was 700r / min. The reaction results are listed in Table 1.
[0087] Example 3
[0088] Catalyst A2 was prepared using the following steps, and dihydrodicyclopentadiene was then prepared.
[0089] (1) Zinc nitrate hexahydrate, nickel acetate, ferric nitrate nonahydrate and a portion of methanol are mixed to obtain the first mixture;
[0090] (2) Mix 2-methylimidazole with another portion of methanol to obtain a second mixture;
[0091] (3) The first mixture and the second mixture are mixed and reacted for 24 hours at room temperature (25°C). Then the mixture is centrifuged and dried to obtain the precursor material.
[0092] (4) The precursor material was heat-treated in a tube furnace at a temperature of 900°C for 2 hours in a nitrogen atmosphere to obtain catalyst A2. Its parameters are listed in Table 1.
[0093] In the first mixture, the concentration of metal ions is 0.0395 mol / L; in the second mixture, the concentration of 2-methylimidazole is 1.58 mol / L; the volume ratio of one part of methanol to another part of methanol is 5:1; and the molar ratio of the metal source to 2-methylimidazole, calculated as metal element, is 1:8.
[0094] The total molar ratio of nickel source (calculated as nickel element) and iron source (calculated as iron element) to zinc source (calculated as zinc element) is 1:8; the molar ratio of nickel source (calculated as nickel element) to iron source (calculated as iron element) is 5:1.
[0095] Catalyst A2 was 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 10%. The mass ratio of catalyst to dicyclopentadiene was 3:20. The reaction temperature was 140℃, the hydrogen pressure was 3MPa, the reaction time was 4h, and the stirring speed was 700r / min. The reaction results are listed in Table 1.
[0096] Example 4
[0097] Catalyst A3 was prepared using the following steps, and dihydrodicyclopentadiene was then prepared.
[0098] (1) Zinc nitrate hexahydrate, nickel nitrate hexahydrate, ferric nitrate nonahydrate and a portion of methanol are mixed to obtain the first mixture;
[0099] (2) Mix 2-methylimidazole with another portion of methanol to obtain a second mixture;
[0100] (3) The first mixture and the second mixture are mixed and reacted for 24 hours at room temperature (25°C). Then the mixture is centrifuged and dried to obtain the precursor material.
[0101] (4) The precursor material was heat-treated in a tube furnace at a temperature of 900°C for 2 hours in a nitrogen atmosphere to obtain catalyst A3. Its parameters are listed in Table 1.
[0102] In the first mixture, the concentration of metal ions is 0.0395 mol / L; in the second mixture, the concentration of 2-methylimidazole is 1.58 mol / L; the volume ratio of one part of methanol to another part of methanol is 5:1; and the molar ratio of the metal source to 2-methylimidazole, calculated as metal element, is 1:8.
[0103] The total molar ratio of nickel source (calculated as nickel element) and iron source (calculated as iron element) to zinc source (calculated as zinc element) is 1:8; the molar ratio of nickel source (calculated as nickel element) to iron source (calculated as iron element) is 1:1.
[0104] Catalyst A3 was 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 10%. The mass ratio of catalyst to dicyclopentadiene was 3:20. The reaction temperature was 140℃, the hydrogen pressure was 3MPa, the reaction time was 4h, and the stirring speed was 700r / min. The reaction results are listed in Table 1.
[0105] Example 5
[0106] Catalyst A4 was prepared using the following steps, and dihydrodicyclopentadiene was then prepared.
[0107] (1) Zinc nitrate hexahydrate, nickel nitrate hexahydrate, ferric nitrate nonahydrate and a portion of methanol are mixed to obtain the first mixture;
[0108] (2) Mix 2-methylimidazole with another portion of methanol to obtain a second mixture;
[0109] (3) The first mixture and the second mixture are mixed and reacted for 24 hours at room temperature (25°C). Then the mixture is centrifuged and dried to obtain the precursor material.
[0110] (4) The precursor material was heat-treated in a tube furnace at a temperature of 900°C for 2 hours in a nitrogen atmosphere to obtain catalyst A4. Its parameters are listed in Table 1.
[0111] In the first mixture, the concentration of metal ions is 0.0395 mol / L; in the second mixture, the concentration of 2-methylimidazole is 1.58 mol / L; the volume ratio of one part of methanol to another part of methanol is 5:1; and the molar ratio of the metal source to 2-methylimidazole, calculated as metal element, is 1:8.
[0112] The total molar ratio of nickel source (calculated as nickel element) and iron source (calculated as iron element) to zinc source (calculated as zinc element) is 1:8; the molar ratio of nickel source (calculated as nickel element) to iron source (calculated as iron element) is 3:1.
[0113] Catalyst A4 was 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 10%. The mass ratio of catalyst to dicyclopentadiene was 3:20. The reaction temperature was 140℃, the hydrogen pressure was 3MPa, the reaction time was 4h, and the stirring speed was 700r / min. The reaction results are listed in Table 1.
[0114] Example 6
[0115] Catalyst A5 was prepared using the following steps, and dihydrodicyclopentadiene was then prepared.
[0116] (1) Zinc nitrate hexahydrate, nickel nitrate hexahydrate, ferric nitrate nonahydrate and a portion of methanol are mixed to obtain the first mixture;
[0117] (2) Mix 2-methylimidazole with another portion of methanol to obtain a second mixture;
[0118] (3) The first mixture and the second mixture are mixed and reacted for 24 hours at room temperature (25°C). Then the mixture is centrifuged and dried to obtain the precursor material.
[0119] (4) The precursor material was heat-treated in a tube furnace at a temperature of 900°C for 2 hours in a nitrogen atmosphere to obtain catalyst A5, the parameters of which are listed in Table 1.
[0120] In the first mixture, the concentration of metal ions is 0.0395 mol / L; in the second mixture, the concentration of 2-methylimidazole is 1.58 mol / L; the volume ratio of one part of methanol to another part of methanol is 5:1; and the molar ratio of the metal source to 2-methylimidazole, calculated as metal element, is 1:8.
[0121] The total molar ratio of nickel source (calculated as nickel element) and iron source (calculated as iron element) to zinc source (calculated as zinc element) is 1:3; the molar ratio of nickel source (calculated as nickel element) to iron source (calculated as iron element) is 8:1.
[0122] Catalyst A5 was 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 10%. The mass ratio of catalyst to dicyclopentadiene was 3:20. The reaction temperature was 140℃, the hydrogen pressure was 3MPa, the reaction time was 4h, and the stirring speed was 700r / min. The reaction results are listed in Table 1.
[0123] Comparative Example 1
[0124] Catalyst D1 was prepared using the following steps, and dihydrodicyclopentadiene was then prepared.
[0125] (1) Zinc nitrate hexahydrate, nickel nitrate hexahydrate and a portion of methanol are mixed to obtain a first mixture;
[0126] (2) Mix 2-methylimidazole with another portion of methanol to obtain a second mixture;
[0127] (3) The first mixture and the second mixture were mixed and reacted for 24 hours at room temperature (25°C). Then the mixture was centrifuged and dried to obtain the precursor material.
[0128] (4) The precursor material was heat-treated in a tube furnace at a temperature of 900°C for 2 hours in a nitrogen atmosphere to obtain catalyst D1, the parameters of which are listed in Table 1.
[0129] In the first mixture, the concentration of metal ions is 0.0395 mol / L; in the second mixture, the concentration of 2-methylimidazole is 1.58 mol / L; the volume ratio of one part of methanol to another part of methanol is 5:1; and the molar ratio of nickel source (calculated as nickel) to zinc source (calculated as zinc) is 1:8.
[0130] Catalyst D1 was 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 10%. The mass ratio of catalyst to dicyclopentadiene was 3:20. The reaction temperature was 120℃, the hydrogen pressure was 3MPa, the reaction time was 8h, and the stirring speed was 700r / min. The reaction results are listed in Table 1.
[0131] Comparative Example 2
[0132] Dihydrodicyclopentadiene was prepared using the method of Example 1, except that catalyst A1 was replaced with Raney nickel catalyst (Inokai) D2 with the same molar amount of active metal. The reaction results are listed in Table 1.
[0133] Table 1
[0134]
[0135]
[0136] according to Figure 1 It can be seen that only broad peaks at 22° and 44° were observed, corresponding to the (002) and (100) crystal planes of carbon, respectively. The above data indicates that the XRD pattern of the catalyst disclosed herein contains only carbon diffraction peaks and no metal diffraction peaks, suggesting that the active metal component in the catalyst disclosed herein does not exhibit significant aggregation. According to... Figure 2 It can be seen that no lattice fringes appear in STEM image (a), indicating that the metal component has not crystallized. The bright spots in image (b) further prove that the metal exists in the form of single atoms. Combining the above characterization and Figure 3 The TEM electron microscopy image shows that the catalyst is a porous carbon-supported single-atom catalyst. In summary, the iron and nickel in the catalyst disclosed herein exist in a single-atom form with high dispersion.
[0137] According to the data in Table 1, the catalysts of this disclosure, which use Ni single atoms and Fe single atoms as active components, exhibit excellent feed conversion, product selectivity and yield in the reaction of dicyclopentadiene to dihydrodicyclopentadiene. Furthermore, when the molar ratio of nickel source (calculated as nickel element) to iron source (calculated as iron element) is within the preferred range, i.e. (5-10):1, even higher feed conversion, dihydrodicyclopentadiene selectivity and yield can be obtained.
[0138] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.
[0139] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.
[0140] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.
Claims
1. A method for preparing dihydrodicyclopentadiene, the method comprising: A hydrogenation reaction is carried out by contacting dicyclopentadiene, hydrogen gas, and a catalyst, characterized in that the method for preparing the catalyst includes the following steps: (1) The metal source and 2-methylimidazole are reacted in a solvent to obtain the precursor material; (2) The precursor material is heat-treated under an inert atmosphere to obtain the catalyst; The metal source includes a zinc source, a nickel source, and an iron source; The molar ratio of the metal source to the 2-methylimidazole, calculated as metal element, is 1:(5-20). The total molar ratio of the nickel source (calculated as nickel) and the iron source (calculated as iron) to the zinc source (calculated as zinc) is 1:(1-12). The catalyst includes a support and an active component; The active components include Ni single atoms and Fe single atoms, and the support is nitrogen-doped porous carbon.
2. The method according to claim 1, wherein, Based on the total weight of the catalyst, the content of Ni element is 0.1-0.6% by weight and the content of Fe element is 0.6-1.7% by weight.
3. The method according to claim 1, wherein, Step (1) includes: S1. The metal source is mixed with a portion of the solvent to obtain a first mixture; S2. The 2-methylimidazole is mixed with another portion of the solvent to obtain a second mixture; S3. Mix the first mixture and the second mixture to carry out the contact reaction.
4. The method according to claim 3, wherein, The volume ratio of one portion of the solvent to the other portion of the solvent is (1-20):
1.
5. The method according to any one of claims 1, 3, and 4, wherein, The molar ratio of the nickel source, calculated as nickel, to the iron source, calculated as iron, is (1-20):
1.
6. The method according to any one of claims 1, 3, and 4, wherein, The zinc source includes one or more of zinc nitrate, zinc acetate, and zinc chloride; The nickel source includes one or more of basic nickel carbonate, nickel nitrate, nickel sulfate, nickel chloride, and nickel acetate; The iron source includes one or more of ferric nitrate, ferric sulfate, ferric chloride, ferrous nitrate, ferrous chloride, and ferrous sulfate; The solvent includes one or more of methanol, ethanol, and water.
7. The method according to claim 1, wherein, In step (1), the contact reaction time is 20-40 h.
8. The method according to claim 1, wherein, In step (2), the inert atmosphere includes one or more of nitrogen, argon, a hydrogen-nitrogen mixture, and a hydrogen-argon mixture; The heat treatment conditions include: a time of 1.5-5 hours and a temperature of 850-1000℃.
9. The method according to claim 1, wherein, The conditions for the hydrogenation reaction include: a temperature of 110-200℃, a hydrogen pressure of 2-8MPa, a time of 8-24h, and a mass ratio of the catalyst to the dicyclopentadiene of 1:(4-12).