Preparation of a bimetallic nickel catalyst based on anthracene skeleton NN coordination and its application in olefin oligomerization

Abstract

The present invention reports a preparation method of a bimetallic nickel catalyst based on anthracene skeleton NN coordination and its application in olefin polymerization. The present invention introduces an anthracene skeleton, improves the high temperature resistance of the catalyst, and by changing the skeleton structure, it is possible to easily regulate the stereo effect and electronic effect of the model metal catalyst, achieve different catalytic performance, and prepare polyolefin polymer materials with various structures and various performances. The novel bimetallic nickel catalyst based on anthracene skeleton NN coordination reported in the present invention has the characteristics of simple preparation, high activity, high temperature resistance, and stable selectivity of the polymerization product 2-butene, and is suitable for ethylene polymerization to prepare 2-butene. Therefore, the bimetallic nickel catalyst based on anthracene skeleton NN coordination reported in the present invention has original innovation and can enhance my country's competitiveness in participating in the international high-end polyolefin polymer material technology market.

Description

Technical Field

[0001] The invention relates to the preparation of a bimetallic nickel catalyst based on anthracene skeleton NN coordination and the application of the catalyst in olefin polymerization. Background Art

[0002] Polymer materials are the pillars of modern science and technology and social development, becoming indispensable and important materials in cutting-edge technology, national defense, and various fields of the national economy. Among them, polyolefins are the fastest-growing, most productive, and most widely used synthetic resins. Industrialized polyethylene catalysts include Ziegler-Natta catalysts (DE Pat. 889229 (1953); IT Pat. 545332 (1956), and IT Pat. 536899 (1955)), Phillips catalysts (Belg. Pat. 530617 (1955)), and metallocene catalysts (W. Kaminsky). Catalytic ethylene oligomerization to produce linear α-olefins (LAOs) has long been a hot topic of research in academia and industry. However, with the rapid expansion of the market for short-chain catalytic ethylene oligomerization to produce linear α-olefins, research in this field is also increasing. The Shell Advanced Olefins Process (Angew. Chem. Int., Ed. 2013, 52, 12492-12496) is one of the largest applications of homogeneous catalysis in industry. It is based on a nickel catalyst containing a monoanionic PO chelating ligand and achieves the production of LAOs in the C4-C20 range with significant α selectivity. Given current market demand trends, the conversion of ethylene to propylene is necessary, as polypropylene has become the second most produced synthetic polymer and the market is rapidly expanding. A promising method for achieving this conversion involves three sequential conversions: (i) ethylene dimerization to 1-butene, (ii) isomerization of 1-butene to 2-butene, and (iii) metathesis of 2-butene with ethylene to propylene. Therefore, selective ethylene oligomerization to 2-butene is an attractive goal.

[0003] The present invention reports a method for preparing a bimetallic nickel catalyst based on an anthracene skeleton NN coordination and its application in olefin polymerization. The present invention introduces an anthracene skeleton, which improves the high-temperature resistance of the catalyst. By changing the skeleton structure, the stereo effect and electronic effect of the model metal catalyst can be easily regulated to achieve different catalytic properties and prepare polyolefin polymer materials with various structures and properties. The novel bimetallic nickel catalyst based on anthracene skeleton NN coordination reported in the present invention has the characteristics of simple preparation, high activity, high temperature resistance, and stable selectivity of the polymerization product 2-butene, and is suitable for the preparation of 2-butene by ethylene polymerization. Therefore, the bimetallic nickel catalyst based on anthracene skeleton NN coordination reported in the present invention is original and innovative and can enhance my country's competitiveness in participating in the international high-end polyolefin polymer material technology market. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a bimetallic nickel catalyst based on anthracene skeleton NN coordination and its application in olefin oligomerization.

[0005] The present invention provides a bimetallic nickel catalyst based on anthracene skeleton NN coordination as shown in formula (I):

[0006]

[0007] Wherein, R is selected from bromine and chlorine.

[0008] The present invention provides a method for preparing the above-mentioned bimetallic nickel catalyst based on anthracene skeleton NN coordination, comprising the following steps:

[0009] Add 2mmol of diiminoanthracene, 4mmol of 6-naphthylpyridine-2-carboxaldehyde and a small amount of p-toluenesulfonic acid to a single-necked flask, reflux in methanol for 24 hours, filter, and the filter residue is the desired ligand; weigh 0.5mmol of the ligand, add anhydrous solvent under a nitrogen atmosphere to turn it into a brown suspension, introduce it into an anhydrous solvent solution containing 1.1mmol of DMENiBr2 and react for 24 hours, concentrate to about 5mL, add ether to wash twice, and drain the filter residue to obtain a bimetallic nickel catalyst based on the anthracene skeleton NN coordination.

[0010] The anhydrous and oxygen-free solvent is selected from dichloromethane, tetrahydrofuran, and toluene.

[0011] The present invention also provides the use of the bimetallic catalyst based on the NN coordination of the anthracene skeleton shown in the above formula (I) in catalyzing olefin polymerization reactions.

[0012] In the above application, the olefin is one or more of ethylene, propylene, styrene, 1-butene, 1-hexene, and 1-octene.

[0013] The catalyst is further added with a co-catalyst, which is one or more of trispentafluorophenylboron, triphenylcarbonium tetrakis(pentafluorophenyl)borate, aluminoxane, alkylaluminum, and alkylaluminum chloride. The aluminoxane is methylaluminoxane, ethylaluminoxane, or isobutylaluminoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum, or tri-n-hexylaluminum; and the alkylaluminum chloride is diethylaluminum monochloride, diethylaluminum sesquichloride, or ethylaluminum dichloride.

[0014] In the above polymerization reaction, the polymerization temperature is 0-180° C., the polymerization pressure is 0.1-5 MPa, and the polymerization solvent is one or more of toluene, hexane, and heptane.

[0015] The present invention provides the preparation of a bimetallic nickel catalyst based on an anthracene skeleton with NN coordination, as well as the use of this catalyst in catalyzing olefin oligomerization. The novel bimetallic nickel catalyst based on anthracene skeleton with NN coordination reported in this invention has the advantages of simple preparation, high activity, high temperature resistance, and stable selectivity for the polymerized product, 2-butene, over a wide temperature range. It is suitable for the production of 2-butene from ethylene oligomerization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a gas chromatography GC analysis chart of the product obtained in Example 4;

[0017] Figure 2 is a gas chromatography GC analysis chart of the product obtained in Example 15;

[0018] Figure 3 is a gas chromatography GC analysis chart of the product obtained in Example 17;

[0019] Figure 4 This is a gas chromatography GC analysis chart of the product obtained in Example 18. DETAILED DESCRIPTION

[0020] The present invention is further described by way of examples, but the present invention is not limited thereto. The examples of the present invention can enable those skilled in the art to more fully understand the present invention.

[0021] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0022] The present invention is described below with reference to specific embodiments.

[0023] Example 1. Preparation of catalyst Ni2

[0024] 2 mmol of 1,8-diaminoanthracene, 4 mmol of 6-naphthylpyridine-2-carboxaldehyde, and 5 mg of p-toluenesulfonic acid were added to a single-necked flask and refluxed in methanol for 24 hours. The mixture was then filtered to obtain the organic ligand with an 82% yield. 0.5 mmol of the organic ligand was added to anhydrous, oxygen-free dichloromethane under a nitrogen atmosphere to produce a brown suspension. This suspension was then introduced into a dichloromethane solution containing 1.1 mmol of DMENiBr2. The reaction was continued for 24 hours, concentrated to approximately 5 mL, and washed twice with ether. The residue was then drained to obtain a bimetallic nickel catalyst Ni2 based on an anthracene skeleton with NN coordination in a 94% yield. Ligand Characterization: 1H NMR (400MHz, CDCl3): δ9.61 (s, 1H), 8.95 (s, 2H), 8.65 (d, J = 7.7Hz, 2H), 8.48 (s, 1H), 8.13 (d, J = 8.0Hz, 2H), 8.01–7.95(m,8H),7.73–7.68(m,4H),7.60(t,J=7.87Hz,2H),7.54–7.47(m,6H),7.21(d,J=7.0Hz,2H)ppm. 13 C NMR (101 MHz, CDCl3): δ 160.95, 159.51, 155.15, 148.74, 138.03, 136.98, 134.14, 132.60, 131.26, 129.35, 128.58, 127.88, 127.71, 126.95, 126.77, 126.66, 126.17, 126.02, 125.96, 125.62, 125.50, 120.16, 119.72, 111.63 ppm. Catalyst Characterization: Anal. Calcd for C 46 H 30 Br4N4Ni2:C,51.36;H,2.81;N,5.21.Found:C,51.22;H,2.67;N,5.28.

[0025] Example 2: Ethylene polymerization catalyzed by Ni2

[0026] In a glove box, 1 μmol of the binuclear catalyst was placed in a 350 ml glass reactor equipped with a stir bar. The reactor was then connected to a high-pressure line, degassed under vacuum, and filled with 0.1 atm of ethylene. Toluene solvent was injected via syringe. An oil bath was used to control the temperature, and the desired amount of cocatalyst was injected. Oligomerization was performed while maintaining an ethylene pressure of 5 atm. While measuring the oligomerization time, the reactor was cooled to -40°C and vented. A small amount of the catalytic mixture was collected and immediately quenched by adding 5% aqueous hydrogen chloride solution at 0°C. The distribution of oligomers in the supernatant was analyzed by gas chromatography. The oligomer yield was calculated based on the mass of toluene. The mass of each component was approximately proportional to its integrated area in the gas chromatogram. Catalytic activity: 0.97 × 10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 72.20%, of which 1-butene selectivity is 33.44% and 2-butene selectivity is 66.56%; C6 selectivity: 27.85%.

[0027] Example 3: Ethylene polymerization catalyzed by Ni2 as catalyst with Et2AlCl as cocatalyst

[0028] The same method as in Example 2 was used, but Et2AlCl was used instead of MAO. The yield and selectivity of oligomers were calculated. Catalytic activity: 0.14×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: >99%.

[0029] Example 4: Ethylene polymerization catalyzed by Ni2 as a catalyst with EtAlCl2 as a cocatalyst

[0030] The same method as in Example 2 was used, but EtAlCl2 was used instead of MAO. The yield and selectivity of oligomers were calculated. Catalytic activity: 0.45×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: >99%.

[0031] Example 5: Ethylene polymerization catalyzed by Ni2 as catalyst with Et3Al as cocatalyst

[0032] The same method as in Example 2 was used, but Et3Al was used instead of MAO to calculate the yield and selectivity of oligomers. Catalytic activity: 0.01×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 76.19%, of which 1-butene selectivity is 37.50% and 2-butene selectivity is 62.50%; C6 selectivity: 23.81%.

[0033] Example 6, catalyst Ni2 i Ethylene Polymerization Catalyzed by Bu3Al

[0034] Same as Example 2, using i Bu3Al replaces MAO and calculates the yield and selectivity of oligomers. Catalytic activity: 0.04×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: >99%.

[0035] Example 7: Ethylene polymerization catalyzed by Ni2 catalyst with Me3Al as a cocatalyst

[0036] The yield and selectivity of oligomers were calculated using the same method as in Example 2, except that Me3Al was used instead of MAO. No polymer was detected in the gas chromatograph (GC).

[0037] Example 8: Catalytic polymerization of ethylene with Ni2 in the presence of different amounts of MAO co-catalyst

[0038] The same method as in Example 2 was used, but Al / Ni = 500 was used instead of Al / Ni = 100 to calculate the yield and selectivity of oligomers. Catalytic activity: 2.01 × 10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 77.62%, of which 1-butene selectivity is 30.22% and 2-butene selectivity is 69.78%; C6 selectivity: 22.38%.

[0039] Example 9: Ethylene polymerization catalyzed by Ni2 with different amounts of MAO co-catalyst

[0040] The same method as in Example 2 was used, but Al / Ni = 1000 was used instead of Al / Ni = 100, and the yield and selectivity of oligomers were calculated. Catalytic activity: 2.55 × 10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 76.19%, of which 1-butene selectivity is 36.48%, 2-butene selectivity is 63.52%; C6 selectivity: 23.81%.

[0041] Example 10: Catalytic polymerization of ethylene with Ni2 in the presence of different amounts of MAO co-catalyst

[0042] The same method as in Example 2 was used, but Al / Ni = 1500 was used instead of Al / Ni = 100 to calculate the yield and selectivity of oligomers. Catalytic activity: 2.03 × 10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 73.88%, of which 1-butene selectivity is 33.87% and 2-butene selectivity is 66.13%; C6 selectivity: 26.12%.

[0043] Example 11: Catalytic polymerization of ethylene with Ni2 in the presence of different amounts of MAO co-catalyst

[0044] The same method as in Example 2 was used, but Al / Ni = 2000 was used instead of Al / Ni = 100 to calculate the yield and selectivity of oligomers. Catalytic activity: 1.70 × 10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 83.90%, of which 1-butene selectivity is 33.40% and 2-butene selectivity is 66.60%; C6 selectivity: 16.01%.

[0045] Example 12: Catalytic polymerization of ethylene by Ni2 in the presence of MAO, Al / Ni=1000 as a co-catalyst at different reaction temperatures

[0046] The same method as in Example 2 was used, except that 20°C was used instead of 50°C, and Al / Ni=1000 was used instead of Al / Ni=100. The yield and selectivity of oligomers were calculated. Catalytic activity: 2.98×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 70.02%, of which 1-butene selectivity is 45.99%, 2-butene selectivity is 54.01%; C6 selectivity: 29.98%.

[0047] Example 13: Catalytic polymerization of ethylene by Ni2 in the presence of MAO, Al / Ni=1000 as a co-catalyst at different reaction temperatures

[0048] The same method as in Example 2 was used, except that 30°C was used instead of 50°C, and Al / Ni=1000 was used instead of Al / Ni=100. The yield and selectivity of oligomers were calculated. Catalytic activity: 4.56×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 75.05%, of which 1-butene selectivity is 41.93% and 2-butene selectivity is 58.07%; C6 selectivity: 24.95%.

[0049] Example 14: Catalytic polymerization of ethylene by Ni2 in the presence of MAO, Al / Ni=1000 as a co-catalyst at different reaction temperatures

[0050] The same method as in Example 2 was used, except that 70°C was used instead of 50°C, and Al / Ni=1000 was used instead of Al / Ni=100. The yield and selectivity of oligomers were calculated. Catalytic activity: 1.41×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 83.28%, of which 1-butene selectivity is 27.57%, 2-butene selectivity is 72.43%; C6 selectivity: 16.72%.

[0051] Example 15: Catalytic polymerization of ethylene by Ni2 in the presence of MAO, Al / Ni=1000 as a co-catalyst at different reaction temperatures

[0052] The same method as in Example 2 was used, except that 90°C was used instead of 50°C, and Al / Ni=1000 was used instead of Al / Ni=100. The yield and selectivity of oligomers were calculated. Catalytic activity: 1.22×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 74.24%, of which 1-butene selectivity is 24.36%, 2-butene selectivity is 75.64%; C6 selectivity: 25.76%.

[0053] Example 16: Catalytic polymerization of ethylene by Ni2 at different reaction times

[0054] The method is the same as that in Example 2, except that 5 min is used instead of 15 min, Al / Ni=1000 is used instead of Al / Ni=100, and 30°C is used instead of 50°C. The yield and selectivity of oligomers are calculated. Catalytic activity: 2.09×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 83.19%, of which 1-butene selectivity is 43.47% and 2-butene selectivity is 56.53%; C6 selectivity: 18.81%.

[0055] Example 17: Ethylene polymerization catalyzed by Ni2 at different reaction times

[0056] The same method as in Example 2 was used, except that 30 min was used instead of 15 min, Al / Ni=1000 was used instead of Al / Ni=100, and 30°C was used instead of 50°C. The yield and selectivity of oligomers were calculated. Catalytic activity: 3.43×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 87.88%, of which 1-butene selectivity is 39.58%, 2-butene selectivity is 60.15%; C6 selectivity: 12.12%.

[0057] Example 18: Ethylene polymerization catalyzed by Ni2 in different solvent systems

[0058] The same method as in Example 2 was used, except that dichloromethane was used instead of toluene, Al / Ni=1000 was used instead of Al / Ni=100, and 30°C was used instead of 50°C. The yield and selectivity of the oligomer were calculated. Catalytic activity: 16.42×10 6 g mol -1 (Ni)h -1 ; C4 selectivity: 75.33%, of which 1-butene selectivity is 33.28%, 2-butene selectivity is 66.72%; C6 selectivity: 24.66%.

Claims

1. A bimetallic nickel catalyst based on anthracene skeleton NN coordination, whose structure is shown in formula (I): in, R is selected from bromine and chlorine.

2. The preparation method of the bimetallic nickel catalyst based on the NN coordination of anthracene skeleton according to claim 1, comprising the following steps: adding 2 mmol of diiminoanthracene, 4 mmol of 6-naphthylpyridine-2-carboxaldehyde and a small amount of p-toluenesulfonic acid to a single-necked bottle, refluxing in methanol for 24 hours, filtering, and the filter residue is the desired ligand; weighing 0.5 mmol of the ligand, adding an anhydrous solvent under a nitrogen atmosphere to form a brown suspension, introducing it into an anhydrous solvent solution containing (DME)NiBr2 1.1 mmol to react for 24 hours, concentrating to 5 mL, adding ether to wash twice, and draining the filter residue to obtain a bimetallic nickel catalyst based on the NN coordination of anthracene skeleton.

3. The preparation method according to claim 2, wherein: The anhydrous solvent is selected from dichloromethane, tetrahydrofuran, and toluene.

4. A method for olefin polymerization, characterized in that: The catalyst for the reaction is the bimetallic nickel catalyst based on the anthracene skeleton NN coordination as described in claim 1.

5. The method according to claim 4, characterized in that: The olefin is ethylene.

6. The method according to claim 4, characterized in that: The catalyst is further added with a co-catalyst, which is one or more of tris(pentafluorophenylboron), triphenylcarbonium tetrakis(pentafluorophenyl)borate, aluminoxane, alkylaluminum and alkylaluminum chloride; the aluminoxane is methylaluminoxane, ethylaluminoxane or isobutylaluminoxane; the alkylaluminum is trimethylaluminum, triethylaluminum, triisobutylaluminum or tri-n-hexylaluminum; the alkylaluminum chloride is diethylaluminum monochloride, diethylaluminum sesquichloride or ethylaluminum dichloride.

7. The method according to claim 4, characterized in that: The polymerization temperature is 0-180° C., the polymerization pressure is 0.1-5 MPa, and the polymerization solvent is one or more of toluene, dichloromethane, hexane, and heptane.

Images