Catalyst, preparation method therefor and use thereof

Abstract

The present invention relates to a catalyst, a preparation method therefor and the use thereof, belonging to the technical field of catalysts. The catalyst comprises a chromium compound, a diaryloxy compound and an ether compound, the molar ratio of the chromium compound to the diaryloxy compound being1:1-1:100, and the molar ratio of the diaryloxy compound to the ether compound being 1:1-1:600. The catalyst in the present invention at least comprises one chromium compound, at least one metal Mg-containing diaryloxy compound and at least one ether compound, and can highly selectively catalyze an ethylene trimerization reaction, thereby improving the reaction activity of the catalyst and increasing the yield. In the ethylene trimerization reaction, the catalyst in the present invention is activated by an alkyl aluminum cocatalyst, the catalyst is capable of catalyzing ethylene trimerization reactions under high-temperature and high-pressure conditions, and the content of waxy by-products is at a relatively low level.

Description

Catalyst, its preparation method and application TECHNICAL FIELD

[0001] The present application relates to the field of catalyst technology, in particular to a catalyst, its preparation method and application. BACKGROUND

[0002] 1-hexene as an intermediate of reaction raw material is widely used in chemical industry, mainly used for the production of polymerization products. But the production process of 1-hexene is relatively complex, the traditional ethylene oligomerization reaction gets Schulz-Flory distribution of multi-component LAO (linear alpha-olefin), which needs to be further separated to obtain the required short-chain alpha-olefin (such as 1-hexene and 1-octene); and the selective ethylene oligomerization reaction mainly obtains 1-hexene and 1-octene, which not only improves the yield of short-chain alpha-olefin, but also greatly reduces the cost of separation.

[0003] PNP ligand is an early used ligand skeleton, in 2002, Wass et al. of British Petroleum (BP) company found that MeO Ph2PNPPh2 MeO The system composed of the ligand and [CrCl3(THF)3] and methylaluminoxane (MAO) (Chem. Commun., 2002, 858) has an activity of 10 6 , the selectivity of 1-hexene reaches 90%, which shows that MeO Ph2PNPPh2 MeO The ligand can well catalyze ethylene trimerization after coordination with chromium precursor. Subsequently, in 2003, McGuinness et al. found that the SNS ligand has a very high content of C6 (93%-95%) in ethylene oligomerization reaction at 80℃, 4MPa ethylene pressure, and the selectivity of 1-hexene in C6 is more than 99% (J. Am. Chem. Soc., 2003, 5272). The above phenomenon provides support for screening catalysts for ethylene trimerization reaction. SUMMARY

[0004] In order to solve at least one of the defects of poor selectivity, reaction activity and yield of the ethylene trimerization catalyst in the prior art at a higher reaction temperature, the present application provides a catalyst, its preparation method and application. The catalyst of the present application contains at least one chromium compound, at least one metal element-containing aryl dioxy compound and at least one ether compound, which can catalyze ethylene trimerization reaction with high selectivity at a higher reaction temperature, so as to improve the reaction activity of the catalyst and increase the yield.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] One of the purposes of the present application is a catalyst comprising:

[0007] a chromium compound comprising one or more of chromium (III) chloride tetrahydrofuran, chromium (III) acetylacetonate, chromium (III) acetate or chromium (III) 2-ethylhexanoate;

[0008] an aryldioxy compound comprising at least one aryldioxy compound containing Mg element;

[0009] an ether compound comprising one or more of diethyl ether, di-n-propyl ether, diisopropyl ether, butyl phenyl ether, methyl tert-butyl ether, diphenyl ether, o-diethyl ether, 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, phenetol or dibenzyl ether;

[0010] wherein the molar ratio between the chromium compound and the aryldioxy compound is 1:1-1:100; the molar ratio between the aryldioxy compound and the ether compound is 1:1-1:600.

[0011] Further, the chromium compound is preferably chromium (III) chloride tetrahydrofuran and / or chromium (III) acetylacetonate.

[0012] Further, the aryldioxy compound containing Mg element has the general formula Mg[(O)2Ph(R) m ], wherein m is an integer of 0-4, and R is one or more of hydrogen, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, allyl, propargyl, tolyl, formyl, acetyl, benzoyl, nitro, nitroso, fluorine, bromine, iodine, chlorine, amino, dimethylamino, adamantyl, diethylamino, benzyloxycarbonyl, tert-butyloxycarbonyl, (isopropylisobutyl)methyl, (diisopropyl)methyl, (isopropylcyclohexyl)methyl, (isobutylcyclohexyl)methyl, (cyclopentylcyclohexyl)methyl, (1,2,5-trimethyl)cyclohexyl, 1-phenylcyclohexyl, 1-naphthylcyclohexyl, triphenylmethyl, 1-naphthylisobutyl, 1-phenylisopropyl, 1-cyclohexyl.

[0013] Still further, when m=4, (O)2Ph(R) m is preferably of the following general formula:

[0014] R1-R4 can be the same or different, and R1-R4 are selected from one or more of hydrogen, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, allyl, propargyl, tolyl, formyl, acetyl, benzoyl, nitro, nitroso, fluoro, bromo, iodo, chloro, amino, dimethylamino, adamantyl, diethylamino, benzyloxycarbonyl, t-butoxycarbonyl, (isopropylisobutyl)methyl, (diisopropyl)methyl, (isopropylcyclohexyl)methyl, (isobutylcyclohexyl)methyl, (cyclopentylcyclohexyl)methyl, (1,2,5-trimethyl)cyclohexyl, 1-phenylcyclohexyl, 1-naphthylcyclohexyl, triphenylmethyl, 1-naphthylisobutyl, 1-phenylisopropyl, and 1-cyclohexyl. Preferably, R1, R2, R3, and R4 are each selected from one of hydrogen, methyl, or phenyl.

[0015] Further, the ether compound is preferably anisole and / or phenetol.

[0016] Further, the molar ratio between the chromium compound and the aromatic dioxy compound is 1:1-1:30; and the molar ratio between the aromatic dioxy compound and the ether compound is 1:1-1:100.

[0017] The second object of the present application is a preparation method of the catalyst as described above, comprising the following steps:

[0018] S1, adding a first solution containing an aromatic dioxy compound and an ether compound into an alkyl magnesium to obtain a mixed solution;

[0019] S2, adding a second solution containing a chromium compound into the mixed solution to obtain the catalyst.

[0020] Further, the alkyl magnesium is preferably di-n-butyl magnesium.

[0021] Further, in the present application, the adding sequence of the aromatic dioxy compound and the ether compound in the first solution is not specifically required, which can be adding the aromatic dioxy compound into the ether compound, or adding the ether compound into the aromatic dioxy compound.

[0022] Further, in S1, the first solution further contains a saturated hydrocarbon and / or an aromatic hydrocarbon; and in S2, the second solution further contains a saturated hydrocarbon and / or an aromatic hydrocarbon.

[0023] The saturated hydrocarbon includes one or more of cyclohexane, n-hexane, methylcyclohexane, n-heptane or n-butane; and the aromatic hydrocarbon includes one or more of benzene, toluene, o-xylene, m-xylene or p-xylene. Specifically, the catalyst of the present application is used in a subsequent reaction in a solvent, and the solvent used is a saturated hydrocarbon (such as cyclohexane, n-hexane, methylcyclohexane, n-heptane, n-butane) and an aromatic hydrocarbon (such as benzene, toluene, o-xylene, m-xylene, p-xylene). The concentration of chromium in the solution is 1x10 -7 to 1 mol / L, preferably 1x10 -6 to 1 mol / L.

[0024] The third object of the present application is the use of the catalyst as described above in the catalysis of ethylene trimerization.

[0025] Further, the specific application method is as follows: the reaction container is vacuumized, the catalyst and the co-catalyst are injected into the reaction container, the temperature is raised to the reaction temperature, the pressure of ethylene is raised to the reaction pressure, and the ethylene trimerization is carried out.

[0026] The co-catalyst is an aluminum compound, and the aluminum compound is selected from one or more of trimethylaluminum (TMA), triethylaluminum (TEA), chlorodiethylaluminum (DEAC), dichloroethylaluminum, methylaluminoxane (MAO), ethylaluminoxane (EAO) or modified methylaluminoxane (MMAO).

[0027] The molar ratio of the chromium compound to the aluminum compound is 1:1-1:50, preferably 1:1-1:18, and the ethylene trimerization is carried out at a pressure of 1-10 MPa and a temperature of 25-200℃.

[0028] Specifically, in the present application, the ethylene trimerization is carried out intermittently according to the following steps:

[0029] i) introducing the catalyst into the reaction container;

[0030] ii) adding a co-catalyst for activation, which can be selected from alkylaluminum, halogen-containing alkylaluminum and aluminoxane, and is preferably triethylaluminum and methylaluminoxane;

[0031] iii) setting the temperature to the reaction temperature;

[0032] iv) introducing ethylene to raise the pressure to the reaction pressure;

[0033] The ethylene trimerization is carried out at a pressure of 1-10 MPa and a temperature of 25-200℃.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] (1) The catalyst of the present application contains at least one chromium compound, at least one aromatic dioxy compound containing Mg element, and at least one ether compound, and can catalyze the trimerization of ethylene with high selectivity, so that the reaction activity of the catalyst is significantly improved and the yield is significantly increased.

[0036] (2) In the trimerization of ethylene, the catalyst of the present application is activated by an aluminum alkyl cocatalyst, and can catalyze the trimerization of ethylene under high temperature and high pressure conditions, and the content of waxy by-products is at a relatively low level. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below, which are implemented on the premise of the technical solutions of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following embodiments.

[0038] Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. If the specific conditions are not specified, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are conventional products that can be purchased on the market.

[0039] The endpoints of the ranges and any values disclosed in the present application are not limited to the precise values stated. The ranges and values should be interpreted as being approximate. Individual endpoints of the ranges, the endpoints of the ranges and individual points, and individual points can be combined with each other to form one or more new ranges of values, which should be considered as being specifically disclosed in the present application.

[0040] The catalyst of the present application is used in subsequent reactions in a solvent, and the solvent used is saturated hydrocarbons (such as cyclohexane, n-hexane, methylcyclohexane, n-heptane, n-butane) and aromatic hydrocarbons (such as benzene, toluene, o-xylene, m-xylene, p-xylene). The concentration of chromium in the solution is 1x10 -7 to 1 mol / L, preferably 1x10 -6 to 1 mol / L.

[0041] The ratio in the present application is:

[0042] i) The molar ratio between the chromium compound and the aromatic dioxy compound containing Mg element is 1:1-1:10, preferably 1:1-1:10;

[0043] ii) The molar ratio between the aromatic dioxy compound containing Mg element and the ether compound is 1:1-1:600, preferably 1:1-1:100;

[0044] iii) the molar ratio of the chromium compound and the aluminum compound is 1:1-1:50, preferably 1:1-1:18.

[0045] In the present application, the trimerization of ethylene is carried out intermittently according to the following steps:

[0046] i) introducing the catalyst into a 100 mL reactor;

[0047] ii) adding at least one aluminum compound for activation, which can be selected from alkyl aluminum, halogen-containing alkyl aluminum, and aluminoxane, etc., preferably triethyl aluminum and methyl aluminoxane;

[0048] iii) setting the temperature to the reaction temperature;

[0049] iv) passing in ethylene, and increasing the pressure to the reaction pressure;

[0050] wherein the trimerization of ethylene is carried out at a pressure of 1-10 MPa and a temperature of 25-200°C.

[0051] In the following examples and comparative examples, the chromium compound used in the present application is chromium (III) chloride tetrahydrofuran, represented as CrCl3(THF)3; the aryl dioxy compound containing Mg element used is phenyl magnesium dioxy, represented as Mg[(O)2Ph]; the ether compound used is phenetol, and the solvent used is cyclohexane; the experimental process is carried out in an inert gas atmosphere.

[0052] Comparative Example 1: Synthesis of Mg[(O)2Ph] / CrCl3(THF)3 solution (Catalyst I)

[0053] Under a nitrogen atmosphere, 4.08 mL of dibutyl magnesium (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. The above obtained solution was added to 1.48 g of CrCl3(THF)3 and 5 mL of cyclohexane solution to obtain the catalyst solution.

[0054] Comparative Example 2: Synthesis of Mg[(O)2Ph] / CrCl3(THF)3 solution (Catalyst II)

[0055] Under a nitrogen atmosphere, 4.08 mL of dibutyl magnesium (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. The above obtained solution was added to 1.48 g of CrCl3(THF)3 and 5 mL of cyclohexane solution to obtain the catalyst solution.

[0056] Comparative Example 3: Synthesis of a solution of Mg[(O)2Ph] / CrCl3(THF)3 (Catalyst III)

[0057] A solution of 0.44 g of 1,2-dihydroxybenzene (4 mmol), 1.83 mL of cyclohexane and 34 mL of anisole was added to 4.08 mL of dibutyl magnesium (4 mmol) under a nitrogen atmosphere to obtain a solution of 4 mmol of Mg[(O)2Ph]. The catalyst solution was obtained by adding 1.48 g of CrCl3(THF)3to the above obtained solution.

[0058] Example 1: Synthesis of a solution of Mg[(O)2Ph] / CrCl3(THF)3 (Catalyst IV)

[0059] A solution of 0.44 g of 1,2-dihydroxybenzene (4 mmol), 1.83 mL of cyclohexane and 34 mL of anisole was added to 4.08 mL of dibutyl magnesium (4 mmol) under a nitrogen atmosphere to obtain a solution of 4 mmol of Mg[(O)2Ph]. The catalyst solution was obtained by adding 1.48 g of CrCl3(THF)3to the above obtained solution.

[0060] Example 2: Synthesis of a solution of Mg[(O)2Ph] / CrCl3(THF)3 (Catalyst V)

[0061] A solution of 0.44 g of 1,2-dihydroxybenzene (4 mmol), 1.83 mL of cyclohexane and 34 mL of anisole was added to 4.08 mL of dibutyl magnesium (4 mmol) under a nitrogen atmosphere to obtain a solution of 4 mmol of Mg[(O)2Ph]. The catalyst solution was obtained by adding 1.48 g of CrCl3(THF)3and 5 mL of cyclohexane solution to 4 mmol of Mg[(O)2Ph].

[0062] Application Examples 1-4: Evaluation of the ethylene trimerization ability of catalysts I-V

[0063] The ethylene trimerization reaction was carried out in a reactor with a volume of 100 mL and a temperature control device. First, the reactor was continuously evacuated at high temperature for 1 h, and then the catalyst and the cocatalyst triethyl aluminum were injected into the reactor after cooling to the desired temperature. Subsequently, the reactor was heated, and when the temperature reached 135°C, the ethylene was introduced at a pressure of 5.5 MPa, and the reaction was started. After 30 min, the ethylene was stopped, and the reactor was cooled and depressurized. Finally, the reaction products were analyzed by gas chromatography. The product composition obtained is given in the following table:

[0064] The above descriptions are only the preferred embodiments of the present application, not intended to limit the present application in other forms. Any skilled person in the art can make changes or modifications to the equivalent embodiments with the disclosed technical contents. However, any simple modification, equivalent change and modification made to the above embodiments without departing from the technical solution of the present application and according to the technical essence of the present application still belong to the protection scope of the present application.

Claims

1. A catalyst characterized in that, Comprise: a chromium compound comprising one or more of chromium (III) chloride tetrahydrofuran, chromium (III) acetylacetonate, chromium (III) acetate or chromium (III) 2-ethylhexanoate; an aryldioxy compound comprising at least one aryldioxy compound containing Mg element; an ether compound comprising one or more of diethyl ether, di-n-propyl ether, diisopropyl ether, butyl phenyl ether, methyl tert-butyl ether, diphenyl ether, o-phenylenedioxy ether, 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, phenetol or dibenzyl ether; wherein the molar ratio between the chromium compound and the aryldioxy compound is 1:1-1:100; the molar ratio between the aryldioxy compound and the ether compound is 1:1-1:

600.

2. The catalyst of claim 1, wherein The chromium compound is preferably chromium (III) chloride tetrahydrofuran and / or chromium (III) acetylacetonate.

3. The catalyst of claim 1, wherein The metal-containing Mg element-containing aromatic dioxy compound general formula is Mg[(O)2Ph(R) m ], wherein m is an integer from 0 to 4, R is one or more of a hydrogen group, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, an allyl group, an propargyl group, a tolyl group, a formyl group, an acetyl group, a benzoyl group, a nitro group, a nitroso group, a fluoro group, a bromo group, an iodo group, a chloro group, an amino group, a dimethylamino group, an adamantyl group, a diethylamino group, a benzyloxycarbonyl group, a tert-butyloxycarbonyl group, a (isopropylisobutyl)methyl group, a (diisopropyl)methyl group, a (isopropylcyclohexyl)methyl group, a (isobutylcyclohexyl)methyl group, a (cyclopentylcyclohexyl)methyl group, a (1,2,5-trimethyl)cyclohexyl group, a 1-phenylcyclohexyl group, a 1-naphthylcyclohexyl group, a triphenylmethyl group, a 1-naphthylisobutyl group, a 1-phenylisopropyl group, and a 1-cyclohexyl group.

4. A catalyst according to claim 3, characterised in that (O)2Ph(R) when m = 4 m Preferably, the compounds are of the general formula: In the formula, R1-R4 can be the same or different, and R1-R4 is selected from one or more of hydrogen, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, allyl, propargyl, tolyl, formyl, acetyl, benzoyl, nitro, nitroso, fluorine, bromine, iodine, chlorine, amino, dimethylamino, adamantyl, diethylamino, benzyloxycarbonyl, tert-butyloxycarbonyl, (isopropylisobutyl)methyl, (diisopropyl)methyl, (isopropylcyclohexyl)methyl, (isobutylcyclohexyl)methyl, (cyclopentylcyclohexyl)methyl, (1,2,5-trimethyl)cyclohexyl, 1-phenylcyclohexyl, 1-naphthylcyclohexyl, triphenylmethyl, 1-naphthylisobutyl, 1-phenylisopropyl and 1-cyclohexyl.

5. The catalyst of claim 1, wherein The ether compound is preferably anisole and / or phenetol.

6. The catalyst of claim 1, wherein The molar ratio between the chromium compound and the aryldioxy compound is 1:1-1:30; the molar ratio between the aryldioxy compound and the ether compound is 1:1-1:

100.

7. A process for the preparation of a catalyst as claimed in any one of claims 1 to 6, characterized in that Comprise the following steps: S1, adding a first solution containing an aryldioxy compound and an ether compound to an alkyl magnesium to obtain a mixed solution; S2, adding a second solution containing a chromium compound to the mixed solution to obtain a catalyst.

8. A process for the preparation of a catalyst according to claim 7, characterized in that, In S1, the first solution further contains saturated hydrocarbon and / or aromatic hydrocarbon; in S2, the second solution further contains saturated hydrocarbon and / or aromatic hydrocarbon; wherein the saturated hydrocarbon comprises one or more of cyclohexane, n-hexane, methylcyclohexane, n-heptane or n-butane; the aromatic hydrocarbon comprises one or more of benzene, toluene, o-xylene, m-xylene or p-xylene.

9. Use of a catalyst as claimed in any one of claims 1 to 6, characterised in that, The catalyst is applied to the catalysis of ethylene trimerization reaction.

10. Use of a catalyst according to claim 9, characterised in that, The specific application method is: vacuumize the reaction container, inject the catalyst and the co-catalyst into the reaction container, heat to the reaction temperature, pressurize to the reaction pressure by ethylene, and then perform ethylene trimerization reaction; wherein the co-catalyst is an aluminum compound; the aluminum compound is selected from one or more of trimethylaluminum, triethylaluminum, chlorodiethylaluminum, dichloroethylaluminum, methylaluminoxane, ethylaluminoxane or modified methylaluminoxane; The molar ratio of the chromium compound and the aluminum compound is 1:1-1:50; the ethylene trimerization is carried out at a pressure of 1-10 MPa and a temperature of 25-200 ℃.

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