Catalyst as well as preparation method and application thereof
By using a catalyst composed of chromium compounds, aromatic dioxygen compounds containing metallic Mg, and ether compounds, the problem of insufficient selectivity and yield of catalysts in the ethylene trimerization reaction at high temperatures was solved, and a highly active and selective ethylene trimerization reaction was achieved.
Patent Information
- Application Number
- CN202411156998.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2026-03-03
AI Technical Summary
Existing ethylene trimerization catalysts have defects in selectivity and yield at higher reaction temperatures, resulting in poor catalytic activity and yield.
A catalyst composed of a chromium compound, an aromatic dioxygen compound containing metallic Mg, and an ether compound is used to catalyze the trimerization of ethylene under high temperature and high pressure through a specific molar ratio and solvent system.
This improved the catalyst's reactivity and yield, reduced the formation of waxy byproducts, and achieved highly selective ethylene trimerization.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of catalyst technology, specifically to a catalyst, its preparation method, and its application. Background Technology
[0002] 1-Hexene, as an intermediate in the reaction process, is widely used in the chemical industry, mainly for the production of polymerization products. However, the production process of 1-hexene is relatively complex. Traditional ethylene oligomerization yields multi-component LAOs (linear α-olefins) with a Schulz-Flory distribution, which require further separation to obtain the desired short-chain α-olefins (such as 1-hexene and 1-octene). In contrast, selective ethylene oligomerization mainly yields 1-hexene and 1-octene, which not only improves the yield of short-chain α-olefins but also significantly reduces the separation cost.
[0003] PNP ligands were among the earliest ligand skeletons used, discovered by Wasss et al. of BP in 2002. MeO Ph2PNPPh2 MeO The system consisting of the ligand with [CrCl3(THF)3] and methylaluminoxane (MAO) (Chem. Commun., 2002, 858) exhibits an activity on the order of 10 at ethylene pressure of 2 MPa. 6 The selectivity for 1-hexene reached 90%, indicating that... MeO Ph2PNPPh2 MeO The ligands, after coordination with the chromium precursor, can effectively catalyze the trimerization of ethylene. Subsequently, in 2003, McGuinness et al. discovered that the SNS ligands underwent ethylene oligomerization at 80 °C and 4 MPa ethylene pressure, with extremely high C6 content (93%-95%), and the selectivity of 1-hexene in C6 was consistently above 99% (J. Am. Chem. Soc., 2003, 5272). These phenomena provide support for screening catalysts for the ethylene trimerization reaction. Summary of the Invention
[0004] To address at least one of the shortcomings of existing ethylene trimerization catalysts in terms of selectivity, reactivity, and yield at higher reaction temperatures, this invention provides a catalyst, its preparation method, and its applications. The catalyst of this invention contains at least one chromium compound, at least one metal-containing aromatic dioxygen compound, and at least one ether compound, enabling it to catalyze the ethylene trimerization reaction with high selectivity at higher reaction temperatures, thereby improving the catalyst's reactivity and increasing the yield.
[0005] The objective of this invention can be achieved through the following technical solutions:
[0006] One objective of this invention is to provide a catalyst comprising:
[0007] Chromium compounds, including one or more of tetrahydrofuran chromium(III) chloride, chromium(III) acetylacetone, chromium(III) acetate, or chromium(III) 2-ethylhexanoate;
[0008] Aryl dioxy compounds, including at least one aryl dioxy compound containing the metal Mg;
[0009] Ether compounds, including one or more of the following: diethyl ether, di-n-propyl ether, diisopropyl ether, butylphenyl ether, methyl tert-butyl ether, diphenyl ether, diethyl phthalate, ethyl butyl ether, dibutyl ether, dipentyl ether, diisopentyl ether, dihexyl ether, tetrahydrofuran, 3-methylfuran, dioxolane, 1,4-dioxane, propylene oxide, dichlorodiethyl ether, dichlorodiisopropyl ether, anisole, phenethyl ether, or dibenzyl ether;
[0010] The molar ratio between the chromium compound and the aromatic dioxygen compound is 1:1 to 1:100; the molar ratio between the aromatic dioxygen compound and the ether compound is 1:1 to 1:600.
[0011] Furthermore, the chromium compound is preferably chromium(III) tetrahydrofuran chloride and / or chromium(III) acetylacetone.
[0012] Furthermore, the general formula of the aromatic dioxygenated compound containing the metallic Mg element is Mg[(O)2Ph(R)]. m ], where m is an integer from 0 to 4, and R is one or more of the following: hydrogen, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, allyl, propargyl, tolyl, formyl, acetyl, benzoyl, nitro, nitrosyl, fluorine, bromo, iodo, chloro, amino, dimethylamino, adamantyl, diethylamino, benzyloxycarbonyl, tert-butoxycarbonyl, (isopropylisobutyl)methyl, (bisisopropyl)methyl, (isopropylcyclohexyl)methyl, (isobutylcyclohexyl)methyl, (cyclopentylcyclohexyl)methyl, (1,2,5-trimethyl)cyclohexyl, 1-phenylcyclohexyl, 1-naphthylcyclohexyl, triphenylmethyl, 1-naphthylisobutyl, 1-phenylisopropyl, and 1-cyclohexyl.
[0013] Furthermore, when m = 4, (O)2Ph(R) m The preferred general formula is as follows:
[0014]
[0015] R1-R4 in the formula may be the same or different, and R1-R4 are selected from one or more of the following: hydrogen group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, tert-butyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, phenyl group, allyl group, propargyl group, tolyl group, formyl group, acetyl group, benzoyl group, nitro group, nitrosyl group, fluorinyl group, bromo group, iodo group, chloro group, amino group, dimethylamino group, adamantyl group, diethylamino group, benzyloxycarbonyl group, tert-butoxycarbonyl group, (isopropylisobutyl)methyl group, (bisisopropyl)methyl group, (isopropylcyclohexyl)methyl group, (isobutylcyclohexyl)methyl group, (cyclopentylcyclohexyl)methyl group, (1,2,5-trimethyl)cyclohexyl group, 1-phenylcyclohexyl group, 1-naphthylcyclohexyl group, triphenylmethyl group, 1-naphthylisobutyl group, 1-phenylisopropyl group, and 1-cyclohexyl group. Preferably, R1, R2, R3 and R4 are selected from one of hydrogen, methyl or phenyl.
[0016] Furthermore, the ether compound is preferably anisole and / or phenethyl ether.
[0017] Furthermore, the molar ratio between the chromium compound and the aromatic dioxygen compound is 1:1 to 1:30; the molar ratio between the aromatic dioxygen compound and the ether compound is 1:1 to 1:100.
[0018] A second objective of this invention is a method for preparing the catalyst as described above, comprising the following steps:
[0019] S1. The first solution containing aromatic dioxygen compounds and ether compounds is added to alkyl magnesium to obtain a mixed solution;
[0020] S2. Add the second solution containing the chromium compound to the mixture to obtain the catalyst.
[0021] Furthermore, the alkyl magnesium is preferably di-n-butyl magnesium.
[0022] Furthermore, in this invention, the order in which the aromatic dioxygen compound and the ether compound are added to the first solution is not specifically required. The aromatic dioxygen compound can be added dropwise to the ether compound, or the ether compound can be added dropwise to the aromatic dioxygen compound.
[0023] Furthermore, in S1, the first solution also contains saturated hydrocarbons and / or aromatic hydrocarbons; in S2, the second solution also contains saturated hydrocarbons and / or aromatic hydrocarbons.
[0024] The saturated hydrocarbons include one or more of cyclohexane, n-hexane, methylcyclohexane, n-heptane, or n-butane; the aromatic hydrocarbons include one or more of benzene, toluene, o-xylene, m-xylene, or p-xylene. Specifically, the catalyst of the present invention carries out subsequent reactions in a solvent, which includes saturated hydrocarbons (e.g., cyclohexane, n-hexane, methylcyclohexane, n-heptane, n-butane) and aromatic hydrocarbons (e.g., benzene, toluene, o-xylene, m-xylene, p-xylene). The concentration of chromium in the solution is 1 × 10⁻⁶. -7 For concentrations up to 1 mol / L, 1×10⁻⁶ is preferred. -6 Up to 1 mol / L.
[0025] A third objective of this invention is the application of a catalyst as described above, which is used to catalyze the trimerization reaction of ethylene.
[0026] Furthermore, the specific application method is as follows: the reaction vessel is evacuated, the catalyst and co-catalyst are injected into the reaction vessel, the temperature is raised to the reaction temperature, and the pressure is increased to the reaction pressure through ethylene to carry out the ethylene trimerization reaction;
[0027] The cocatalyst is an aluminum compound; the aluminum compound is selected from one or more of trimethylaluminum (TMA), triethylaluminum (TEA), diethylaluminum chloride (DEAC), dichloroethylaluminum, methylaluminoxane (MAO), ethylaluminoxane (EAO), or modified methylaluminoxane (MMAO);
[0028] The molar ratio of the chromium compound to the aluminum compound is 1:1-1:50, preferably 1:1-1:18; the ethylene trimerization reaction is carried out under a pressure of 1-10 MPa and a temperature of 25-200°C.
[0029] Specifically, in this invention, the ethylene trimerization reaction is carried out intermittently according to the following steps:
[0030] i) Introduce the catalyst into the reaction vessel;
[0031] ii) Activation is performed by adding a co-catalyst, which can be selected from alkylaluminum, halogenated alkylaluminum and aluminum oxane, with triethylaluminum and methylaluminoxane being preferred;
[0032] iii) Set the temperature to the reaction temperature;
[0033] iv) Introduce ethylene to increase the pressure to the reaction pressure;
[0034] Ethylene trimerization is carried out under pressure of 1-10 MPa and temperature of 25-200℃.
[0035] Compared with the prior art, the present invention has the following beneficial effects:
[0036] (1) The catalyst of the present invention contains at least one chromium compound, at least one aromatic dioxygen compound containing the metal Mg element, and at least one ether compound, which can catalyze the trimerization reaction of ethylene with high selectivity, thereby significantly improving the reaction activity of the catalyst and significantly increasing the yield.
[0037] (2) In the ethylene trimerization reaction, the catalyst of the present invention is activated by an alkylaluminum co-catalyst. The catalyst can catalyze the ethylene trimerization reaction under high temperature and high pressure conditions, and the content of waxy byproducts is at a relatively low level. Detailed Implementation
[0038] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.
[0039] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Unless otherwise specified, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.
[0040] The endpoints and any values of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.
[0041] The catalyst of this invention carries out subsequent reactions in a solvent, which may include saturated hydrocarbons (e.g., cyclohexane, n-hexane, methylcyclohexane, n-heptane, n-butane) and aromatic hydrocarbons (e.g., benzene, toluene, o-xylene, m-xylene, p-xylene). The concentration of chromium in the solution is 1 × 10⁻⁶. -7 For concentrations up to 1 mol / L, 1×10⁻⁶ is preferred. -6 Up to 1 mol / L.
[0042] The proportional relationships in this invention are as follows:
[0043] i) The molar ratio between the chromium compound and the aryl dioxy compound containing the metallic Mg element is 1:1-1:10, preferably 1:1-1:10;
[0044] ii) The molar ratio of the aromatic dioxygen compound containing the metallic Mg element to the ether compound is 1:1 to 1:600, preferably 1:1 to 1:100;
[0045] iii) The molar ratio of chromium compound to aluminum compound is 1:1 to 1:50, preferably 1:1 to 1:18.
[0046] In this invention, the trimerization reaction of ethylene is carried out intermittently according to the following steps:
[0047] i) Introduce the catalyst into a 100 mL reaction vessel;
[0048] ii) Activate by adding at least one aluminum compound, which may be selected from alkylaluminum, halogenated alkylaluminum and aluminum oxane, with triethylaluminum and methylaluminoxane being preferred;
[0049] iii) Set the temperature to the reaction temperature;
[0050] iv) Introduce ethylene to increase the pressure to the reaction pressure;
[0051] Ethylene trimerization is carried out under pressure of 1-10 MPa and temperature of 25-200℃.
[0052] In the following examples and comparative examples, the chromium compound used in this invention is tetrahydrofuran chromium chloride (III), denoted as CrCl3(THF)3; the aromatic dioxygen compound containing the metal Mg element used is phenyldioxymagnesium, denoted as Mg[(O)2Ph]; the ether compound used is phenethyl ether, and the solvent used is cyclohexane; all experiments were conducted in an inert gas atmosphere.
[0053] Comparative Example 1 : Solution for synthesis of Mg[(O)2Ph] / CrCl3(THF)3 (catalyst I)
[0054] Under a nitrogen atmosphere, 4.08 mL of dibutylmagnesium (4 mmol) was added to 0.44 g of 1,2-dihydroxybenzene (4 mmol) and 36 mL of cyclohexane to obtain a 4 mmol Mg[(O)₂Ph] solution. This solution was then added to 1.48 g of CrCl₃(THF)₃ and 5 mL of cyclohexane to obtain the catalyst solution.
[0055] Comparative Example 2 : Solution for synthesizing Mg[(O)2Ph] / CrCl3(THF)3 (catalyst II)
[0056] Under a nitrogen atmosphere, 4.08 mL of dibutylmagnesium (4 mmol) was added to a liquid consisting of 0.44 g of 1,2-dihydroxybenzene (4 mmol), 1.83 mL of cyclohexane, and 34 mL of phenethyl ether to obtain a 4 mmol Mg[(O)₂Ph] solution. This solution was then added to 1.48 g of CrCl₃(THF)₃ to obtain the catalyst solution.
[0057] Comparative Example 3 Solution for synthesizing Mg[(O)₂Ph] / CrCl₃(THF)₃ (catalyst III)
[0058] Under a nitrogen atmosphere, a solution consisting of 0.44 g of 1,2-dihydroxybenzene (4 mmol), 1.83 mL of cyclohexane, and 34 mL of phenethyl ether was added to 4.08 mL of dibutylmagnesium (4 mmol) to obtain a 4 mmol Mg[(O)₂Ph] solution. This solution was then added to a solution of 1.48 g of CrCl₃(THF)₃ and 5 mL of cyclohexane to obtain the catalyst solution.
[0059] Example 1 : Solution for synthesis of Mg[(O)2Ph] / CrCl3(THF)3 (catalyst IV)
[0060] Under a nitrogen atmosphere, a liquid consisting of 0.44 g of 1,2-dihydroxybenzene (4 mmol), 1.83 mL of cyclohexane, and 34 mL of phenethyl ether was added to 4.08 mL of dibutylmagnesium (4 mmol) to obtain a 4 mmol Mg[(O)₂Ph] solution. Then, 1.48 g of CrCl₃(THF)₃ was added to the above solution to obtain the catalyst solution.
[0061] Example 2 : Solution for synthesizing Mg[(O)2Ph] / CrCl3(THF)3 (catalyst V)
[0062] Under a nitrogen atmosphere, a liquid consisting of 0.44 g of 1,2-dihydroxybenzene (4 mmol), 1.83 mL of cyclohexane, and 34 mL of phenethyl ether was added to 4.08 mL of dibutylmagnesium (4 mmol) to obtain a 4 mmol Mg[(O)₂Ph] solution. Then, 1.48 g of CrCl₃(THF)₃ and 5 mL of cyclohexane solution were added to the 4 mmol Mg[(O)₂Ph] solution to obtain the catalyst solution.
[0063] Application Examples 1-4 Evaluation of the catalytic ability of catalysts I-V for ethylene trimerization
[0064] Ethylene trimerization was conducted in a 100 mL reactor equipped with a temperature control device. First, the reactor was continuously evacuated at high temperature for 1 hour. After cooling to the desired temperature, the catalyst and co-catalyst triethylaluminum were injected into the reactor. The reactor temperature was then raised to 135 °C, and ethylene was introduced at a pressure of 5.5 MPa to initiate the reaction. After 30 minutes of reaction, the ethylene supply was stopped, and the reactor was cooled and depressurized. Finally, the reaction products were analyzed by gas chromatography. The composition of the obtained products is shown in the table below:
[0065]
[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.
Claims
1. A catalyst, characterized in that, include: Chromium compounds, including one or more of tetrahydrofuran chromium(III) chloride, chromium(III) acetylacetone, chromium(III) acetate, or chromium(III) 2-ethylhexanoate; Aryl dioxy compounds, including at least one aryl dioxy compound containing the metal Mg; Ether compounds, including one or more of the following: diethyl ether, di-n-propyl ether, diisopropyl ether, butylphenyl ether, methyl tert-butyl ether, diphenyl ether, diethyl phthalate, ethyl butyl ether, dibutyl ether, dipentyl ether, diisopentyl ether, dihexyl ether, tetrahydrofuran, 3-methylfuran, dioxolane, 1,4-dioxane, propylene oxide, dichlorodiethyl ether, dichlorodiisopropyl ether, anisole, phenethyl ether, or dibenzyl ether; The molar ratio between the chromium compound and the aromatic dioxygen compound is 1:1 to 1:100; the molar ratio between the aromatic dioxygen compound and the ether compound is 1:1 to 1:
600.
2. The catalyst according to claim 1, characterized in that, The chromium compound is preferably chromium(III) chloride in tetrahydrofuran and / or chromium(III) acetylacetone.
3. The catalyst according to claim 1, characterized in that, The general formula of the aromatic dioxygenated compound containing the metallic Mg element is Mg[(O)2Ph(R)]. m ], where m is an integer from 0 to 4, and R is one or more of the following: hydrogen, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, allyl, propargyl, tolyl, formyl, acetyl, benzoyl, nitro, nitrosyl, fluorine, bromo, iodo, chloro, amino, dimethylamino, adamantyl, diethylamino, benzyloxycarbonyl, tert-butoxycarbonyl, (isopropylisobutyl)methyl, (bisisopropyl)methyl, (isopropylcyclohexyl)methyl, (isobutylcyclohexyl)methyl, (cyclopentylcyclohexyl)methyl, (1,2,5-trimethyl)cyclohexyl, 1-phenylcyclohexyl, 1-naphthylcyclohexyl, triphenylmethyl, 1-naphthylisobutyl, 1-phenylisopropyl, and 1-cyclohexyl.
4. The catalyst according to claim 3, characterized in that, When m = 4, (O)2Ph(R) m The preferred general formula is as follows: R1-R4 in the formula may be the same or different, and R1-R4 are selected from one or more of the following: hydrogen group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, tert-butyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, phenyl group, allyl group, propargyl group, tolyl group, formyl group, acetyl group, benzoyl group, nitro group, nitrosyl group, fluorinyl group, bromo group, iodo group, chloro group, amino group, dimethylamino group, adamantyl group, diethylamino group, benzyloxycarbonyl group, tert-butoxycarbonyl group, (isopropylisobutyl)methyl group, (bisisopropyl)methyl group, (isopropylcyclohexyl)methyl group, (isobutylcyclohexyl)methyl group, (cyclopentylcyclohexyl)methyl group, (1,2,5-trimethyl)cyclohexyl group, 1-phenylcyclohexyl group, 1-naphthylcyclohexyl group, triphenylmethyl group, 1-naphthylisobutyl group, 1-phenylisopropyl group, and 1-cyclohexyl group.
5. The catalyst according to claim 1, characterized in that, The ether compound is preferably anisole and / or phenethyl ether.
6. The catalyst according to claim 1, characterized in that, The molar ratio between the chromium compound and the aromatic dioxygen compound is 1:1 to 1:30; the molar ratio between the aromatic dioxygen compound and the ether compound is 1:1 to 1:
100.
7. A method for preparing the catalyst according to any one of claims 1-6, characterized in that, Includes the following steps: S1. The first solution containing aromatic dioxygen compounds and ether compounds is added to alkyl magnesium to obtain a mixed solution; S2. Add the second solution containing the chromium compound to the mixture to obtain the catalyst.
8. The method for preparing a catalyst according to claim 7, characterized in that, In S1, the first solution further contains saturated hydrocarbons and / or aromatic hydrocarbons; in S2, the second solution further contains saturated hydrocarbons and / or aromatic hydrocarbons. The saturated hydrocarbons include one or more of cyclohexane, n-hexane, methylcyclohexane, n-heptane, or n-butane; the aromatic hydrocarbons include one or more of benzene, toluene, o-xylene, m-xylene, or p-xylene.
9. The use of a catalyst as described in any one of claims 1-6, characterized in that, This catalyst is used to catalyze the trimerization of ethylene.
10. The application of the catalyst according to claim 9, characterized in that, The specific application method is as follows: the reaction vessel is evacuated, the catalyst and co-catalyst are injected into the reaction vessel, the temperature is raised to the reaction temperature, and the pressure is increased to the reaction pressure through ethylene to carry out the ethylene trimerization reaction; The co-catalyst is an aluminum compound; the aluminum compound is selected from one or more of trimethylaluminum, triethylaluminum, diethylaluminum chloride, dichloroethylaluminum, methylaluminoxane, ethylaluminoxane, or modified methylaluminoxane. The molar ratio of the chromium compound to the aluminum compound is 1:1 to 1:50; the ethylene trimerization reaction is carried out under a pressure of 1-10 MPa and a temperature of 25-200°C.