CN115999643B

CN115999643B - Oil-soluble nano catalyst and preparation method and application thereof

Info

Publication number: CN115999643B
Application number: CN202310028543.3A
Authority: CN
Inventors: 王兴永; 黎剑浩; 傅送保; 陈和; 于超; 雷帅
Original assignee: China National Offshore Oil Corp CNOOC; CNOOC Oil and Petrochemicals Co Ltd; CNOOC Chemical and New Material Science Research Institute Beijing Co Ltd; CNOOC Qingdao Heavy Oil Processing Engineering Technology Research Center Co Ltd
Current assignee: China National Offshore Oil Corp CNOOC; CNOOC Oil and Petrochemicals Co Ltd; CNOOC Chemical and New Material Science Research Institute Beijing Co Ltd; CNOOC Qingdao Heavy Oil Processing Engineering Technology Research Center Co Ltd
Priority date: 2023-01-09
Filing date: 2023-01-09
Publication date: 2024-07-19
Anticipated expiration: 2043-01-09
Also published as: CN115999643A

Abstract

The invention relates to an oil-soluble nano catalyst, a preparation method and application thereof, which are used for solving the problems that a homogeneous catalyst has a product and a catalyst are difficult to separate, and a heterogeneous catalyst has poor activity and low olefin conversion rate. The oil-soluble nano catalyst comprises a metal center, an oil layer wrapping the metal center and a phosphine-containing ligand. The catalyst provided by the invention takes rhodium metal as an active center, and the outer layer is coated with an oil layer and a phosphine-containing ligand, so that the catalyst has excellent dispersibility in a reaction system, has the characteristics of good catalytic activity and good stability, can overcome the defects that the catalyst and a product are difficult to separate in a homogeneous system and the activity of a heterogeneous catalytic system is poor, and is suitable for industrial application.

Description

Oil-soluble nano catalyst and preparation method and application thereof

Technical Field

The invention relates to the field of nano catalyst preparation, in particular to an oil-soluble nano catalyst, a preparation method and application thereof, and especially relates to an oil-soluble nano catalyst for olefin hydroformylation, a preparation method and application thereof.

Background

At present, the hydroformylation reaction (Hydroformlation) is also called an OXO reaction, which refers to the reaction of olefin and synthesis gas (H ₂ and CO) to generate aldehyde or alcohol compounds under the catalysis of transition metal. The aldehyde compound can be further converted into compounds such as alcohols, acids, esters, aldol condensation products, acetals, etc., which are widely used in medicines, agricultural chemicals, perfumes, detergents, plasticizers, surfactants, etc.

The hydroformylation reaction is focused on the choice of the catalytic system, and in theory the metals that are capable of undergoing the insertion reaction are potential catalysts. Since the discovery of the reaction, the research of a catalytic system is mainly focused on Co, rh, pt, fe, pd, ru and other transition metals, and only metal Co and Rh are really used for industrial scale production.

The homogeneous catalysis system has high catalytic activity, better selectivity and mild reaction condition, and the industrial olefin hydroformylation reaction is still mainly carried out by the homogeneous catalysis system. However, most of the catalytic active centers used in the reaction are noble metals and are easily dissolved in the reaction solvent, so that the recovery is difficult, a great deal of waste is caused, and the production cost is greatly increased. Another technical difficulty with homogeneous catalysts for catalyzing olefin hydroformylation reaction systems is the separation of the catalyst from the product, i.e., how to prevent loss of active catalyst components. Heterogeneous catalyst immobilization is an effective means for solving the problem that the catalyst and the product are difficult to separate, heterogeneous catalyst can be realized through covalent bond fixation, polymer encapsulation, solid loading and other methods, but the current immobilized hydroformylation catalyst is generally poor in reaction activity, and the industrialization way of the catalyst is hindered.

As in the prior art [ Reaction Kinetics, MECHANISMS AND CATALYSIS,2015,116 (1): 223-234 ], triphenylphosphine polymer supported rhodium catalysts synthesized by different methods are disclosed, and have better activity and selectivity on propylene hydroformylation. Rh/POL-PPh ₃ performs better in terms of catalytic activity, since the one-pot synthesis readily allows the insertion of rhodium catalysts into the polymer, which affects not only the coordination of the metal rhodium and phosphine ligands, but also the transfer rate of the hydroformylation reaction mass.

Prior art [ Top Catal,2011,54 (5-7): 299-307 ] discloses a silica supported triphenylphosphine modified heterogeneous rhodium catalyst which shows good chemical selectivity in the hydroformylation of propylene, no propane and alcohol by-products are produced, and the reaction area can reach 14.

Li et al [ Nano Research,2014,7 (9): 1364-1369.] studied a porous transparent MOF supported Rh@ZIF-8 type Nano catalyst which showed good catalytic activity in the hydroformylation reaction, the chemical selectivity of 1-hexene was 92%, but the regioselectivity was poor, and l/b was only 0.9.

The prior art [ CATALYSIS SCIENCE & Technology,2016,6 (4): 1162-1172 ] discloses a supported rhodium catalyst obtained by reducing a trivalent rhodium compound of graphene oxide, in which rhodium metal is located on the surface of nano-graphene, thus having very high dispersibility and extremely small nano-size. The catalyst showed poor chemoselectivity (38.4% for 1-hexene) and regioselectivity (4/b) in the hydroformylation reaction.

The prior art [ Nat Commun,2016,7,14036] discloses a CoO supported monoatomic rhodium catalyst which has poor propylene conversion and regioselectivity in the hydroformylation of propylene.

CN10144475A discloses a method for preparing a catalyst with mesoporous molecular sieve or silicon dioxide as carrier, haloalkyltrimethylsilane and lithium diphenylphosphine as coupling agent, and immobilized active rhodium complex, the catalyst obtained by the method has firm active center, is not easy to run off, can be well separated from the reaction system, but has poor catalyst activity and low olefin conversion rate.

That is, the current homogeneous catalyst has the problem of difficult separation of the product and the catalyst, while the heterogeneous catalyst has the problems of poor activity and low olefin conversion rate.

Disclosure of Invention

In view of the problems existing in the prior art, the invention aims to provide an oil-soluble nano catalyst, a preparation method and application thereof, so as to solve the problems that a homogeneous catalyst has a product and a catalyst are difficult to separate, and a heterogeneous catalyst has poor activity and low olefin conversion rate.

To achieve the purpose, the invention adopts the following technical scheme:

In a first aspect, the present invention provides an oil soluble nanocatalyst comprising a metal center and an oil layer surrounding the metal center and a phosphine-containing ligand.

The catalyst provided by the invention takes rhodium metal as an active center, and the outer layer is coated with an oil layer and a phosphine-containing ligand, so that the catalyst has excellent dispersibility in a reaction system, has the characteristics of good catalytic activity and good stability, can overcome the defects that the catalyst and a product are difficult to separate in a homogeneous system and the activity of a heterogeneous catalytic system is poor, and is suitable for industrial application.

In the present invention, the phosphine-containing ligand may be any of the structures L1 to L8:

as a preferred embodiment of the present invention, the metal center includes a rhodium cobalt compound.

As a preferred embodiment of the present invention, the oil layer includes oleic acid and oleylamine.

In a second aspect, the present invention provides a method for preparing the oil-soluble nanocatalyst according to the first aspect, the method comprising:

Mixing and reacting oleic acid-rhodium reaction liquid, oleylamine-cobalt reaction liquid and a solvent to obtain a bimetallic compound, then carrying out reduction treatment on the bimetallic compound in a mixed atmosphere to obtain a nano catalyst, and washing and ligand replacement are sequentially carried out on the obtained nano catalyst to obtain the oil-soluble nano catalyst.

As a preferable technical scheme of the invention, the oleic acid-rhodium reaction liquid is obtained by carrying out a first heat preservation reaction on a rhodium compound and oleic acid;

Preferably, the rhodium compound comprises Rh(OAc)₃、Rhacac(CO)₂、Rh₄(CO)₁₂、[Rh(OAc)(COD)]₂、RhCl₃、Rh(acac)₃、 rhodium hexafluoroacetylacetonate or a combination of at least 2 of rhodium trifluoroacetylacetonates.

Preferably, the molar ratio of rhodium compound to oleic acid in the first incubation reaction is 1 (1-10), and may be, for example, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, or 10:1, etc., but is not limited to the recited values, and other non-recited values within this range are equally applicable, preferably 1 (3-8).

The temperature of the first heat-retaining reaction is preferably 80 to 160 ℃, and may be, for example, 80 ℃, 85 ℃, 90 ℃, 95 ℃,100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, 145 ℃, 150 ℃, 155 ℃, 160 ℃, or the like, but is not limited to the recited values, and other values not recited in the range are equally applicable.

Preferably, the time of the first heat-preserving reaction is 30-60min, for example, 30min, 32min, 34min, 36min, 38min, 40min, 42min, 44min, 46min, 48min, 50min, 52min, 54min, 56min, 58min or 60min, etc., but not limited to the recited values, and other non-recited values within the range are equally applicable.

Preferably, the oleylamine-cobalt reaction solution is obtained by performing a second heat preservation reaction on a cobalt compound and oleylamine.

Preferably, the cobalt compound comprises 1 or a combination of at least 2 of cobalt acetate, cobalt octoate, cobalt acetylacetonate, cobalt chloride or cobalt hexafluoroacetylacetonate.

Preferably, the molar ratio of cobalt compound to oleylamine in the second incubation reaction is 1 (3-15), for example 1:3、1:3.5、1:4、1:4.5、1:5、1:5.5、1:6、1:6.5、1:7、1:7.5、1:8、1:8.5、1:9、1:9.5、1:10、1:10.5、1:11、1:11.5、1:12、1:12.5、1:13、1:13.5、1:14、1:14.5 or 1:15, but not limited to the values recited, other values not recited in this range are equally applicable, preferably 1 (5-9).

The temperature of the second incubation reaction is preferably 60 to 120 ℃, and may be, for example, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, or the like, but is not limited to the recited values, and other values not recited in the range are equally applicable.

Preferably, the time of the second incubation reaction is 0.5-2h, for example, but not limited to, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h, etc., and other non-enumerated values within this range are equally applicable.

As a preferred embodiment of the present invention, the solvent includes 1 or a combination of at least 2 of diphenyl ether, benzyl ether, tri-n-octylamine or octadecene.

Preferably, the molar ratio of rhodium compound to cobalt compound in the mixed material is 1 (0.5-3), for example 1:0.5、1:0.6、1:0.7、1:0.8、1:0.9、1:1、1:1.1、1:1.2、1:1.3、1:1.4、1:1.5、1:1.6、1:1.7、1:1.8、1:1.9、1:2、1:2.1、1:2.2、1:2.3、1:2.4、1:2.5、1:2.6、1:2.7、1:2.8、1:2.9 or 1:3, but not limited to the recited values, and other non-recited values within this range are equally applicable.

Preferably, the temperature of the reaction is 260-320 ℃, such as 260℃、262℃、264℃、266℃、268℃、270℃、272℃、274℃、276℃、278℃、280℃、282℃、284℃、286℃、288℃、290℃、292℃、294℃、296℃、298℃、300℃、302℃、304℃、306℃、308℃、310℃、312℃、314℃、316℃、318℃ or 320 ℃, but not limited to the recited values, other non-recited values within this range are equally applicable.

Preferably, the reaction time is 9-11h, for example 9h、9.1h、9.2h、9.3h、9.4h、9.5h、9.6h、9.7h、9.8h、9.9h、10h、10.1h、10.2h、10.3h、10.4h、10.5h、10.6h、10.7h、10.8h、10.9h or 11h, etc., but is not limited to the recited values, and other non-recited values within this range are equally applicable.

As a preferable technical scheme of the invention, the mixed atmosphere comprises nitrogen and hydrogen with the volume ratio of (6-12): 1, for example, 6:1、7:1、8:1、9:1、9.1:1、9.2:1、9.3:1、9.4:1、9.5:1、9.6:1、9.7:1、9.8:1、9.9:1、10:1、10.1:1、10.2:1、10.3:1、10.4:1、10.5:1、10.6:1、10.7:1、10.8:1、10.9:1、11:1 or 12:1 and the like, but the mixed atmosphere is not limited to the listed values, and other non-listed values in the range are applicable.

The temperature of the reduction treatment is preferably 190 to 260 ℃, and may be 190 to 195 ℃, 200 ℃, 205 ℃, 210 ℃, 215 ℃, 220 ℃, 225 ℃, 230 ℃, 235 ℃, 240 ℃, 245 ℃, 250 ℃, 255 ℃, 260 ℃ or the like, for example, but not limited to the values recited, and other values not recited in the range are equally applicable.

Preferably, the time of the reduction treatment is 12-36h, for example, 12h, 14h, 16h, 18h, 20h, 22h, 24h, 26h, 28h, 30h, 32h, 34h or 36h, etc., but not limited to the recited values, other non-recited values within the range are equally applicable.

As a preferred embodiment of the present invention, the agent used in the washing comprises ethanol and/or isopropanol. Other alcoholic reagents such as ethanol and the like are also possible.

Preferably, the number of times of washing is not less than 2, for example, 2,3, 4 or 5 times, etc., but not limited to the recited values, other non-recited values within the range are equally applicable.

Preferably, the molar ratio of the nanocatalyst to phosphine-containing ligand in the ligand exchange is 1 (1-8), for example, may be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, or 1:8, etc., but is not limited to the recited values, and other non-recited values within this range are equally applicable.

Preferably, the ligand exchange time is 2-10h, for example, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h or 10h, etc., but not limited to the recited values, other non-recited values within this range are equally applicable.

The temperature of the ligand exchange is preferably 30 to 70 ℃, and may be, for example, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃,60 ℃, 65 ℃, or 70 ℃, etc., but is not limited to the values recited, and other values not recited in the range are equally applicable.

As a preferable technical scheme of the invention, the preparation method comprises the following steps: mixing and reacting oleic acid-rhodium reaction liquid, oleylamine-cobalt reaction liquid and a solvent to obtain a bimetallic compound, then carrying out reduction treatment on the bimetallic compound in a mixed atmosphere to obtain a nano catalyst, and washing and ligand replacement are sequentially carried out on the obtained nano catalyst to obtain the oil-soluble nano catalyst;

The oleic acid-rhodium reaction liquid is obtained by carrying out a first heat preservation reaction on a rhodium compound and oleic acid; the rhodium compound comprises Rh(OAc)₃、Rhacac(CO)₂、Rh₄(CO)₁₂、[Rh(OAc)(COD)]₂、RhCl₃、Rh(acac)₃、 rhodium hexafluoroacetylacetonate or a combination of 1 or at least 2 rhodium trifluoroacetylacetonates; the molar ratio of rhodium compound to oleic acid in the first heat preservation reaction is 1 (1-10); the temperature of the first heat preservation reaction is 80-160 ℃; the time of the first heat preservation reaction is 30-60min;

the oleylamine-cobalt reaction liquid is obtained by carrying out a second heat preservation reaction on a cobalt compound and oleylamine; the cobalt compound comprises 1 or a combination of at least 2 of cobalt acetate, cobalt octoate, cobalt acetylacetonate, cobalt chloride or cobalt hexafluoroacetylacetonate; the molar ratio of the cobalt compound to the oleylamine in the second heat preservation reaction is 1 (3-15);

the solvent comprises 1 or a combination of at least 2 of diphenyl ether, benzyl ether, tri-n-octylamine or octadecene; the molar ratio of rhodium compound to cobalt compound in the mixed material is 1 (0.5-3); the temperature of the reaction is 260-320 ℃; the reaction time is 9-11h;

The mixed atmosphere comprises nitrogen and hydrogen with the volume ratio of (6-12) being 1; the temperature of the reduction treatment is 190-260 ℃; the reduction treatment time is 12-36h;

The agent used in the washing comprises ethanol and/or isopropanol; the washing times are more than or equal to 2 times; the molar ratio of the nanocatalyst to the phosphine-containing ligand in the ligand exchange is 1 (1-8); the ligand replacement time is 2-10h; the temperature of the ligand replacement is 30-70 ℃.

In a third aspect, the present invention provides the use of an oil soluble nanocatalyst according to the first aspect, the use comprising: the oil-soluble nano catalyst is used as a catalyst in the hydroformylation of olefins.

In the present invention, the hydroformylation of olefins using the oil-soluble nanocatalyst may be performed in a batch or continuous manner.

In the present invention, the hydroformylation process may be carried out by reacting an olefin with a mixture of gases (volume (0.9-1.1): 1, hydrogen and carbon monoxide) at a temperature of 85-120℃and a pressure of 2-3MPa for a reaction time of 5-30 hours.

Compared with the prior art, the invention has the following beneficial effects:

(1) The synthesis method of the oil-soluble nano catalyst is simple, easy to operate and suitable for industrial scale-up production.

(2) The catalyst has excellent dispersibility in a reaction system, has the characteristics of good catalytic activity and good stability, can overcome the defects that the catalyst and the product are difficult to separate in a homogeneous system and the heterogeneous catalytic system has poor activity, and is suitable for industrial application.

(3) In the hydroformylation reaction, the oil-soluble nano catalyst has high olefin conversion rate, the product selectivity is adjustable and controllable by introducing different oil-soluble ligands to adjust the reaction activity and the regioselectivity, particularly, the positive-to-negative ratio of the monophosphate ligand can be reduced to 1.3-1.8, the positive-to-negative ratio of the bisphosphite ligand can be controlled to be more than 25, and the catalyst can be recycled.

Drawings

FIG. 1 is a scanning electron micrograph of the nanoparticles obtained in example 1 of the present invention at a magnification of 30k and a scale bar of 1. Mu.m;

FIG. 2 is a scanning electron micrograph of the nanoparticles obtained in example 1 of the present invention at 40k magnification to a scale of 1. Mu.m;

FIG. 3 is a particle size distribution diagram of nanoparticles obtained in example 1 of the present invention;

FIG. 4 is an infrared spectrum of the nanoparticle modified with a ligand obtained in example 1 of the present invention;

FIG. 5 is an EDS spectrum of the nanoparticle obtained in example 1 of the present invention.

The present invention will be described in further detail below. The following examples are merely illustrative of the present invention and are not intended to represent or limit the scope of the invention as defined in the claims.

Detailed Description

For a better illustration of the present invention, which is convenient for understanding the technical solution of the present invention, exemplary but non-limiting examples of the present invention are as follows:

example 1

The embodiment provides a preparation method of an oil-soluble nano catalyst, which comprises the following steps:

(1) Firstly, mixing 2g of rhodium chloride with 15g of oleic acid, and reacting for 45min at 100 ℃ to form a reaction liquid I;

(2) Mixing 2.5g of cobalt acetylacetonate and 13g of oleylamine, and then selectively reacting at 90 ℃ for 1h to form a reaction liquid II;

(3) Mixing the reaction solution I and the reaction solution II, adding 20g of diphenyl ether, and reacting at 280 ℃ for 10 hours to form a bimetallic compound;

(4) Introducing a mixture of nitrogen and hydrogen (10:1), and then reducing for 20 hours at 260 ℃ to form a nano catalyst;

(5) The reaction was cooled to room temperature, washed twice with isopropanol solvent, and then 7.5g triphenylphosphine was added thereto for substitution at 45 ℃ for 7 hours, thereby obtaining an oil-soluble nanocatalyst.

The morphology and the composition of the obtained nano particles are characterized by a scanning electron microscope, as shown in figures 1-5, according to the test result of SEM, the average particle diameter is 30nm, the nano particles can be highly dispersed, and the agglomeration phenomenon does not occur; rhodium cobalt catalyst/triphenylphosphine infrared absorption peak 1470,1430; according to EDS analysis, the composition of the nano particles is Rh/Co/O, the atomic percent of Rh is 13.61%, the atomic percent of Co is 15.68%, and the atomic percent of O is 17.84% calculated. The synthesized nano particles can form a uniform and transparent clear system in organic solvents such as toluene and the like, and no precipitate is precipitated after standing.

Example 2

The only difference from example 1 is that rhodium chloride in step (1) is changed to rhodium acetylacetonate.

Example 3

The only difference from example 1 is that rhodium chloride in step (1) is changed to rhodium acetate.

Example 4

The only difference from example 1 is that cobalt acetylacetonate in step (2) was changed to cobalt acetate.

Example 5

The only difference from example 1 is that cobalt acetylacetonate in step (2) was changed to cobalt chloride.

Example 6

The difference from example 1 is only that 2g of rhodium chloride was added in step (1) and 3g of cobalt acetylacetonate was added in step (2).

Example 7

The difference from example 1 is only that the reaction mixture I in step (1) and the reaction mixture II in step (2) were mixed and reacted at 300 ℃.

Example 8

The only difference from example 1 is the replacement of the triphenylphosphine ligand in step (5) with ligand L4.

Example 9

The only difference from example 1 is the replacement of the triphenylphosphine ligand in step (5) with ligand L6.

Example 10

The only difference from example 1 is the replacement of the triphenylphosphine ligand in step (5) with ligand L8.

Example 11

The only difference from example 1 is that oleic acid in step (1) was replaced with an equivalent amount of oleylamine.

Example 12

The only difference from example 1 is that the oleylamine in step (2) was replaced with an equivalent amount of oleic acid.

Example 13

The difference from example 1 is only that oleic acid in step (1) is replaced by an equivalent amount of lauric acid.

Example 14

The only difference from example 1 is that the oleylamine in step (2) was replaced with an equivalent amount of n-hexylamine.

Application example 1

To a 500mL stainless steel autoclave equipped with a pressure gauge, 300mg of the nanocatalyst obtained in examples 1-14 and 25mL of anhydrous toluene were charged under an air atmosphere. The gas pipeline is connected, the gas in the kettle is replaced by nitrogen three times, the specified amount of propylene is introduced, and the mixed gas of hydrogen and carbon monoxide (1:1) is introduced until the total pressure is 2.0MPa. Heating to the required temperature (95 ℃) under magnetic stirring, supplementing air in the middle of the reaction for several times to maintain the total pressure to be 2.0MPa, cooling the reactor after 18 hours of reaction, emptying residual gas in a fume hood, weighing, opening the kettle, sampling, and measuring the normal-to-iso ratio (molar ratio of normal butyraldehyde to isobutyraldehyde) by using Gas Chromatography (GC), wherein the results are shown in Table 1.

TABLE 1

Application example 2

To a 500mL stainless steel autoclave equipped with a pressure gauge, 300mg of the nanocatalyst obtained in example 1 and 25mL of anhydrous toluene were added under an air atmosphere. The gas line was connected, the gas in the autoclave was replaced three times with nitrogen, the olefins specified in Table 2 were added, and a mixture of hydrogen and carbon monoxide (1:1) was introduced to a total pressure of 2.0MPa. Heating to the required temperature (90 ℃) under magnetic stirring, supplementing air in the middle of the reaction for several times to maintain the total pressure to be 2.0MPa, cooling the reactor after the reaction for 24 hours, emptying residual gas in a fume hood, weighing, opening the kettle, sampling, and measuring the normal-to-iso ratio (molar ratio of normal aldehyde to isomeric aldehyde) by using Gas Chromatography (GC), wherein the results are shown in Table 2 in detail.

TABLE 2

	Olefins	Reaction temperature/. Degree.C	Olefin conversion/%	Positive-to-negative ratio
					1	Ethylene	90	99.2	-
2	1-Butene	95	98.3	4.8
					3	1-Hexene	110	97.8	5.6
4	1-Octene	110	97.2	6.3

From the results of the above examples and application examples, it is apparent that the present invention prepares the oil-soluble nanocatalyst of reactivity and stability by forming an oleic acid-coated bimetallic complex of rhodium compound and cobalt compound at high temperature under the action of oleic acid and oleylamine, and then by a reduction-coordination substitution method. The catalyst has excellent dispersibility in a reaction system, has the characteristics of good catalytic activity and good stability, can overcome the defects that the catalyst and the product are difficult to separate in a homogeneous system and the activity of a heterogeneous catalytic system is poor, and is suitable for industrial application.

It is stated that the detailed structural features of the present invention are described by the above embodiments, but the present invention is not limited to the above detailed structural features, i.e., it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope of the present invention and the scope of the disclosure.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.

In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.

Claims

1. An oil-soluble nanocatalyst, characterized in that the oil-soluble nanocatalyst comprises a metal center and an oil layer surrounding the metal center and a phosphine-containing ligand;

the metal center comprises a rhodium cobalt compound; the oil layer comprises oleic acid and oleylamine.

2. A method of preparing the oil soluble nanocatalyst of claim 1, wherein the method of preparing comprises:

3. The method according to claim 2, wherein the oleic acid-rhodium reaction solution is obtained by subjecting a rhodium compound and oleic acid to a first heat-retaining reaction.

4. The method of claim 3, wherein the rhodium compound comprises Rh(OAc)₃、Rhacac(CO)₂、Rh₄(CO)₁₂、[Rh(OAc)(COD)]₂、RhCl₃、Rh(acac)₃、 rhodium hexafluoroacetylacetonate or a combination of at least 2 of rhodium trifluoroacetylacetonates.

5. The process according to claim 3, wherein the molar ratio of rhodium compound to oleic acid in the first heat-retaining reaction is 1 (1-10).

6. The process according to claim 5, wherein the molar ratio of the rhodium compound to oleic acid in the first heat-retaining reaction is 1 (3-8).

7. The method of claim 3, wherein the first incubation is at a temperature of 80-160 ℃.

8. The method of claim 3, wherein the first incubation is for a period of 30 to 60 minutes.

9. The preparation method of claim 2, wherein the oleylamine-cobalt reaction solution is obtained by performing a second heat-preserving reaction on a cobalt compound and oleylamine.

10. The method of claim 9, wherein the cobalt compound comprises 1 or a combination of at least 2 of cobalt acetate, cobalt octoate, cobalt acetylacetonate, cobalt chloride, or cobalt hexafluoroacetylacetonate.

11. The method of claim 9, wherein the molar ratio of cobalt compound to oleylamine in the second incubation reaction is 1 (3-15).

12. The method of claim 11, wherein the molar ratio of cobalt compound to oleylamine in the second incubation reaction is 1 (5-9).

13. The method of claim 9, wherein the second incubation is at a temperature of 60-120 ℃.

14. The method of claim 9, wherein the second incubation is for a period of time ranging from 0.5 to 2 hours.

15. The method of claim 2, wherein the solvent comprises 1 or a combination of at least 2 of diphenyl ether, benzyl ether, tri-n-octylamine, or octadecene.

16. The process according to claim 2, wherein the molar ratio of rhodium compound to cobalt compound in the mixed material is 1 (0.5-3).

17. The process of claim 2, wherein the temperature of the reaction is 260-320 ℃.

18. The process of claim 2, wherein the reaction time is 9 to 11 hours.

19. The method of claim 2, wherein the mixed atmosphere comprises nitrogen and hydrogen in a volume ratio of (6-12): 1.

20. The method of claim 2, wherein the temperature of the reduction treatment is 190-260 ℃.

21. The method of claim 2, wherein the reduction treatment is carried out for a period of time ranging from 12 to 36 hours.

22. The method of claim 2, wherein the agent used in the washing comprises ethanol and/or isopropanol.

23. The method according to claim 2, wherein the number of times of washing is not less than 2.

24. The process of claim 2, wherein the molar ratio of the nanocatalyst to phosphine-containing ligand in the ligand exchange is 1 (1-8).

25. The method of claim 2, wherein the ligand exchange time is 2 to 10 hours.

26. The method of claim 2, wherein the ligand exchange temperature is 30-70 ℃.

27. The method of any one of claims 2-26, wherein the method of preparation comprises:

Mixing and reacting oleic acid-rhodium reaction liquid, oleylamine-cobalt reaction liquid and a solvent to obtain a bimetallic compound, then carrying out reduction treatment on the bimetallic compound in a mixed atmosphere to obtain a nano catalyst, and washing and ligand replacement are sequentially carried out on the obtained nano catalyst to obtain the oil-soluble nano catalyst;

the oleylamine-cobalt reaction liquid is obtained by carrying out a second heat preservation reaction on a cobalt compound and oleylamine; the cobalt compound comprises 1 or a combination of at least 2 of cobalt acetate, cobalt octoate, cobalt acetylacetonate, cobalt chloride or cobalt hexafluoroacetylacetonate; the molar ratio of the cobalt compound to the oleylamine in the second heat preservation reaction is 1 (3-15); the temperature of the second heat preservation reaction is 60-120 ℃; the second heat preservation reaction time is 0.5-2h;

28. Use of the oil soluble nanocatalyst of claim 1, wherein the use comprises: the oil-soluble nano catalyst is used as a catalyst in the hydroformylation of olefins.