A bimetallic catalyst, its preparation method and application

Abstract

This invention discloses a bimetallic catalyst, its preparation method, and its applications. The bimetallic catalyst comprises pretreated graphene oxide and rhodium and nickel supported on the graphene oxide, wherein the molar ratio of nickel to rhodium is 1:10-300. The bimetallic catalyst of this invention exhibits higher activity and selectivity in the hydroformylation reaction of olefins, and also shows good recovery performance after the reaction. The separated catalyst composition can be recycled, reducing production costs and facilitating industrial production applications.

Description

Technical Field

[0001] This invention belongs to the field of hydroformylation technology, specifically relating to a bimetallic catalyst, its preparation method, and its application. Background Technology

[0002] In recent years, with the rapid development of the plastics processing, automotive, cable and construction industries worldwide, the global demand for plasticizers has been increasing, which in turn has increased the demand for plasticizer alcohols, especially the demand for higher carbon alcohols with C6 and above, which has grown rapidly.

[0003] Currently, industrial hydroformylation processes are mainly divided into homogeneous catalysis and two-phase catalysis. Homogeneous catalysis has advantages such as fast reaction rate and high activity, but the product and catalyst need to be separated by distillation. As the carbon chain length increases, the boiling point of the hydroformylation product, the higher carbon aldehyde, increases, requiring higher temperatures for product separation. However, highly active rhodium-based catalysts are easily deactivated at high temperatures; therefore, the high-temperature distillation used in homogeneous catalysis processes leads to the loss of precious metal catalysts, increasing production costs.

[0004] To overcome this challenge, researchers have conducted extensive studies on the heterogeneity of homogeneous catalysts. Among these, supported rhodium catalysts can effectively overcome the problems of catalyst separation and recycling in homogeneous catalysis, making them a hot topic in olefin hydroformylation research. However, current technologies still cannot simultaneously achieve high catalytic activity and product selectivity. Therefore, developing heterogeneous catalysts with high activity and high selectivity is of significant practical importance for the hydroformylation process. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a novel bimetallic catalyst. This catalyst improves the reactivity and aldehyde selectivity of the hydroformylation reaction by pretreating the supported graphene oxide and loading it with rhodium / nickel bimetallic active centers. Furthermore, as a heterogeneous catalyst, this catalyst also exhibits excellent recovery performance after the hydroformylation reaction, and the separated and recovered catalyst composition can be recycled.

[0006] The first aspect of the present invention provides a bimetallic catalyst comprising pretreated graphene oxide and rhodium and nickel supported on the graphene oxide, wherein the molar ratio of nickel to rhodium is 1:10-300, preferably 1:50-200, and more preferably 1:114-190.

[0007] According to some embodiments of the bimetallic catalyst of the present invention, the rhodium content is 0.01-10% by weight, based on the weight of the bimetallic catalyst. In the present invention, the rhodium content in the bimetallic catalyst can be changed by adjusting the concentration of the rhodium leaching solution; however, it has been found through measurement that the bimetallic catalyst of the present invention performs better when the rhodium content is in the range of 0.1-10% by weight.

[0008] According to some embodiments of the bimetallic catalyst of the present invention, the method for preparing the pretreated graphene oxide includes: mixing graphene oxide with ultrapure water, ultrasonically treating it to form a slurry, mixing the slurry with L-ascorbic acid, and washing and drying it.

[0009] According to some embodiments of the bimetallic catalyst described in this invention, the bimetallic catalyst is used for the hydroformylation reaction of olefins.

[0010] A second aspect of the present invention provides a method for preparing a bimetallic catalyst, comprising:

[0011] (a) The pretreated graphene oxide solid was first impregnated with a solution containing a rhodium compound, and then filtered, washed and dried in sequence to obtain rhodium-loaded graphene oxide.

[0012] (b) The rhodium-loaded graphene oxide is second-impregnated with a soluble nickel metal salt solution, and then filtered, washed and dried in sequence to obtain a solid.

[0013] (c) The solid is heated and then cooled.

[0014] According to some embodiments of the preparation method described in this invention, the method for preparing the pretreated graphene oxide solid includes:

[0015] (a0) Graphene oxide is mixed with ultrapure water and ultrasonically treated to form a slurry;

[0016] (a1) The slurry is mixed with L-ascorbic acid, washed and dried to obtain pretreated graphene oxide solid.

[0017] According to some embodiments of the preparation method described in this invention, the weight ratio of graphene oxide to ultrapure water is 0.001-0.003:1.

[0018] According to some embodiments of the preparation method described in this invention, the amount of L-ascorbic acid used is 0.01-1 mg per mL of slurry, preferably 0.01-0.5 mg.

[0019] According to some embodiments of the preparation method described in this invention, the rhodium-containing compound is as shown in formula (I):

[0020] Rh(L 1 ) x (L 2 ) y (L 3 ) z Formula (I)

[0021] Among them, L 1 Selected from carbonyl, halogen, acetylacetone, diphenylphosphine, cyclooctadiene, norbornene, and triphenylphosphine; L 2 and L 3 The same or different, each independently selected from hydrogen, carbonyl, chlorine, acetylacetone, diphenylphosphine, cyclooctadiene, norbornene and triphenylphosphine, x is an integer from 1 to 3, y and z are each independently selected from integers from 0 to 4, and x+y+z≤5.

[0022] According to some embodiments of the preparation method of the present invention, the rhodium-containing compound is selected from at least one of rhodium trichloride, rhodium acetylacetone dicarbonyl, rhodium chlorocarbonyl di(triphenylphosphine trisodium trisulfonate), rhodium chlorocarbonyl di(disulfonate triphenylphosphine disodium), rhodium chlorocarbonyl di(triphenylphosphine monosodium sulfonate), and rhodium chlorocarbonyl tri(triphenylphosphine trisodium trisulfonate).

[0023] According to some embodiments of the preparation method of the present invention, the amount of the rhodium-containing compound used satisfies the following: based on the weight of the bimetallic catalyst, the rhodium content is 0.01-10% by weight (elementally).

[0024] According to some embodiments of the preparation method described in this invention, the soluble nickel metal salt is selected from at least one of nickel sulfate, nickel nitrate, and nickel halide. The nickel halide may be, but is not limited to, nickel chloride.

[0025] According to some embodiments of the preparation method of the present invention, the conditions for the first impregnation include: a temperature of 20-180°C and a time of 12-36 hours.

[0026] According to some embodiments of the preparation method described in this invention, the conditions for the second impregnation include: a temperature of 20-180°C and a time of 1-10 hours.

[0027] According to some embodiments of the preparation method of the present invention, the heating conditions in step (c) include: heating at 100-200°C for 10-60 min in a mixed atmosphere of H2 and He, preferably, heating at 100-200°C for 10-60 min in a 10-50 vol% H2 / He atmosphere. "10-50 vol% H2 / He atmosphere" means that the H2 content in the mixed atmosphere of H2 / He is 10-50 vol%.

[0028] According to some specific embodiments of the preparation method described in this invention, a method for preparing a bimetallic catalyst includes, but is not limited to:

[0029] (a0) Mix graphene oxide and ultrapure water and sonicate for 10-60 minutes to form a slurry.

[0030] (a1) L-ascorbic acid is added to the slurry described in step (a0) at a stirring speed of 3000-5000 rpm, and stirred for 12-36 h, preferably 18-24 h. The slurry is then washed and dried to obtain the treated graphene oxide. The amount of L-ascorbic acid used is 0.01-1 mg / mL, preferably 0.01-0.5 mg / mL.

[0031] (a) Impregnate the graphene oxide solid obtained in step (a1) with a solution containing a rhodium compound, heat the mixture at 20-180°C under inert gas protection and stirring for 12-36 h, then filter, wash and vacuum dry to obtain rhodium-loaded graphene oxide.

[0032] (b) The rhodium-loaded graphene obtained in step (a) was impregnated with a soluble nickel metal salt solution, stirred for 1-10 h under inert gas protection, filtered, washed, and vacuum dried.

[0033] (c) The solid obtained in step (b) is heated at 100-200°C for 10-60 min in a 10-30 vol% H2 / He atmosphere, and then cooled to obtain a highly dispersed rhodium / nickel bimetallic catalyst.

[0034] A third aspect of the present invention provides a bimetallic catalyst prepared according to the above-described method for preparing a bimetallic catalyst. The catalyst comprises pretreated graphene oxide and rhodium and nickel supported on the graphene oxide, wherein the molar ratio of nickel to rhodium is 1:10-300, preferably 1:50-200, and more preferably 1:114-190.

[0035] According to some embodiments of the bimetallic catalyst of the present invention, the rhodium content is 0.01-10% by weight, based on the weight of the bimetallic catalyst.

[0036] The fourth aspect of the present invention provides the application of the above-described bimetallic catalyst or the preparation method of the above-described bimetallic catalyst in the hydroformylation of olefins.

[0037] The beneficial effects of this invention are:

[0038] The bimetallic catalyst of the present invention exhibits higher activity and selectivity in the hydroformylation reaction of olefins, and also has a good recovery effect after the reaction. The separated catalyst composition can be recycled, reducing production costs and facilitating industrial production applications. Detailed Implementation

[0039] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0040] The testing method and equipment used in this invention are as follows:

[0041]

Example 1

[0042] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then, add L-ascorbic acid (0.1mg / mL, 0.1mg of L-ascorbic acid per mL of slurry) while stirring at 4000 rpm. Continue stirring for 24 hours, then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0043] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0044] A nickel nitrate solution with a nickel content of 0.01 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 200 °C for 30 min in a 20 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) was used to determine the rhodium content, which was 2.1 wt% based on the weight of the bimetallic catalyst.

[0045] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0046]

Example 2

[0047] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then add L-ascorbic acid (0.05mg / mL) while stirring at 4000 rpm. Continue stirring for 24 hours. Then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0048] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0049] A nickel nitrate solution with a nickel content of 0.01 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 200 °C for 30 min in a 20 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) analysis showed that the rhodium content in the catalyst was 2.1 wt%.

[0050] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0051]

Example 3

[0052] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then add L-ascorbic acid (0.5mg / mL) while stirring at 4000 rpm. Continue stirring for 24 hours, then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0053] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0054] A nickel nitrate solution with a nickel content of 0.01 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 200 °C for 30 min in a 20 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) analysis showed that the rhodium content in the catalyst was 2.1 wt%.

[0055] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0056]

Example 4

[0057] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then add L-ascorbic acid (0.1mg / mL) while stirring at 4000 rpm. Continue stirring for 24 hours, then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0058] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0059] A nickel nitrate solution with a nickel content of 0.006 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 200 °C for 30 min in a 20 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) analysis showed that the rhodium content in the catalyst was 2.1 wt%.

[0060] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0061]

Example 5

[0062] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then add L-ascorbic acid (0.1mg / mL) while stirring at 4000 rpm. Continue stirring for 24 hours, then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0063] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0064] A nickel nitrate solution with a nickel content of 0.02 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 200 °C for 30 min in a 20 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) analysis showed that the rhodium content in the catalyst was 2.1 wt%.

[0065] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0066]

Example 6

[0067] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then, add L-ascorbic acid (0.1mg / mL, 0.1mg of L-ascorbic acid per mL of slurry) while stirring at 4000 rpm. Continue stirring for 24 hours, then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0068] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0069] A nickel nitrate solution with a nickel content of 0.01 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 100 °C for 60 min in a 30 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) analysis showed that the rhodium content in the catalyst was 2.1 wt%.

[0070] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0071]

Example 7

[0072] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then, add L-ascorbic acid (0.1mg / mL, 0.1mg of L-ascorbic acid per mL of slurry) while stirring at 4000 rpm. Continue stirring for 24 hours, then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0073] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0074] A nickel nitrate solution with a nickel content of 0.004 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 200 °C for 30 min in a 20 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) analysis showed that the rhodium content in the catalyst was 2.1 wt%.

[0075] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0076]

Example 8

[0077] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then, add L-ascorbic acid (0.1mg / mL, 0.1mg of L-ascorbic acid per mL of slurry) while stirring at 4000 rpm. Continue stirring for 24 hours, then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0078] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0079] A nickel nitrate solution with a nickel content of 0.01 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 200 °C for 30 min in a 50 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) analysis showed that the rhodium content in the catalyst was 2.1 wt%.

[0080] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0081] Comparative Example 1

[0082] The experimental method was the same as in Example 1, except that the graphene oxide was not pretreated and the other experimental conditions remained unchanged, and the catalyst was obtained.

[0083] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0084] Comparative Example 2

[0085] The experimental method was the same as in Example 1, except that nickel loading was not performed and the other experimental conditions remained unchanged, thus obtaining the catalyst.

[0086] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0087] Comparative Example 3

[0088] Weigh 1g of graphene oxide and place it in ultrapure water. Sonicate for 30 minutes to form a slurry. Then, add L-ascorbic acid (0.1mg / mL, 0.1mg of L-ascorbic acid per mL of slurry) while stirring at 4000 rpm. Continue stirring for 24 hours, then filter, wash, and vacuum dry at 80℃ for 12 hours to obtain the processed graphene oxide for later use.

[0089] A rhodium trichloride solution with a rhodium content of 2.0% by weight was prepared. 10g of this solution was weighed and used to impregnate the treated graphene oxide. The mixture was stirred at 60℃ under N2 protection for 24h, then filtered, washed and vacuum dried to obtain rhodium-loaded graphene oxide.

[0090] A nickel nitrate solution with a nickel content of 0.25 wt% was prepared. 20 g of this solution was used to impregnate rhodium-loaded graphene oxide. The mixture was stirred for 8 h at room temperature under N2 protection. After filtration, washing, and vacuum drying, it was heated at 200 °C for 30 min in a 20 vol% H2 / He atmosphere. After cooling, a highly dispersed rhodium / nickel bimetallic catalyst was obtained. Inductively coupled plasma mass spectrometry (ICP) analysis showed that the rhodium content in the catalyst was 2.1 wt%.

[0091] The hydroformylation reaction was carried out using a catalyst, and the reaction results are shown in Table 2.

[0092] [Test Example]

[0093] The catalysts of Examples 1-8 and Comparative Examples 1-3 were tested respectively, and their activity and selectivity were determined using a laboratory high-pressure reactor evaluation device. The reactor volume was 50 mL, placed in a heating mantle, and the concentration of the highly dispersed rhodium / nickel bimetallic catalyst was 0.2% by weight. The conditions for determining the catalyst activity and selectivity are shown in Table 1.

[0094] Table 1. Determination conditions for catalyst activity and selectivity

[0095] reaction temperature Reaction pressure Syngas composition reaction time Olefin feedstock solvent 100℃ 4Mpa <![CDATA[H2:CO=1:1]]> 10h 2-Octenene Toluene

[0096] Catalyst activity and selectivity are characterized by olefin conversion and aldehyde selectivity, which are calculated using the following formulas:

[0097]

[0098]

[0099] In the catalyst, the molar ratio (n) of nickel to rhodium is... 镍 / n 铑 The test method for ) is inductively coupled plasma mass spectrometry (ICP).

[0100] The test results are shown in Table 2.

[0101] Table 2. Effect of catalysts on the 2-octene hydroformylation reaction

[0102]

[0103] As can be seen from the comparative examples, the catalyst's reactivity and selectivity are significantly reduced when the support is not pretreated. Furthermore, Comparative Example 3 shows that the effect is poor when the molar ratio of nickel to rhodium is outside the range of this invention. This indicates that bimetallic loading occupies active sites due to the addition of the second metal, and if the molar ratio of nickel to rhodium is inappropriate, the effect is worse than that of monometallic loading.

[0104] The above description is merely a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, based on the technical teachings provided by the present invention and as common knowledge in the field, other equivalent modifications and improvements can be made, and these should also be considered within the scope of protection of the present invention.

Claims

1. A bimetallic catalyst comprising pretreated graphene oxide and rhodium and nickel supported on said graphene oxide, wherein, The molar ratio of nickel to rhodium is 1:10-300; the preparation method of the pretreated graphene oxide includes: mixing graphene oxide with ultrapure water, ultrasonically treating it to form a slurry, mixing the slurry with L-ascorbic acid, and washing and drying it; the bimetallic catalyst is used for the hydroformylation reaction of olefins; Based on the weight of the bimetallic catalyst, the rhodium content is 0.01-10% by weight (elemental).

2. The bimetallic catalyst according to claim 1, characterized in that, The molar ratio of nickel to rhodium in the bimetallic catalyst is 1:50-200.

3. A method for preparing the bimetallic catalyst according to claim 1 or 2, comprising: (a) The pretreated graphene oxide solid was first impregnated with a solution containing a rhodium compound, and then filtered, washed and dried in sequence to obtain rhodium-loaded graphene oxide; (b) The rhodium-loaded graphene oxide is second-impregnated with a soluble nickel metal salt solution, and then filtered, washed and dried sequentially to obtain a solid. (c) The solid is heated and then cooled; The method for preparing the pretreated graphene oxide solid includes: (a0) Graphene oxide is mixed with ultrapure water and ultrasonically treated to form a slurry; (a1) The slurry is mixed with L-ascorbic acid, washed and dried to obtain pretreated graphene oxide solid; The heating conditions in step (c) include heating at 100-200°C for 10-60 minutes in a mixed atmosphere of H2 and He.

4. The preparation method according to claim 3, characterized in that, In step (a0), the weight ratio of graphene oxide to ultrapure water is 0.001-0.003:1; and / or In step (a1), the amount of L-ascorbic acid used is 0.01-1 mg per mL of slurry.

5. The preparation method according to claim 4, characterized in that, In step (a1), the amount of L-ascorbic acid used is 0.01-0.5 mg per mL of slurry.

6. The preparation method according to claim 3, characterized in that, The rhodium-containing compound is shown in formula (I): Rh(L 1 ) x (L 2 ) y (L 3 ) z Formula (I) Among them, L 1 Selected from carbonyl, halogen, acetylacetone, diphenylphosphine, cyclooctadiene, norbornene, and triphenylphosphine; L 2 and L 3 The same or different, each independently selected from hydrogen, carbonyl, chlorine, acetylacetone, diphenylphosphine, cyclooctadiene, norbornene and triphenylphosphine, x is an integer from 1 to 3, y and z are each independently selected from integers from 0 to 4, and x+y+z≤5.

7. The preparation method according to claim 6, characterized in that, The rhodium-containing compound is selected from at least one of rhodium trichloride, rhodium acetylacetone dicarbonyl, rhodium chlorocarbonyl di(triphenylphosphine trisodium trisulfonate), rhodium chlorocarbonyl di(disulfonate triphenylphosphine disodium), rhodium chlorocarbonyl di(triphenylphosphine monosodium sulfonate), and rhodium chlorocarbonyl tri(triphenylphosphine trisodium trisulfonate).

8. The preparation method according to any one of claims 3-7, characterized in that, The soluble nickel metal salt is selected from at least one of nickel sulfate, nickel nitrate, and nickel chloride.

9. The preparation method according to any one of claims 3-7, characterized in that, The conditions for the first impregnation include: a temperature of 20-180°C and a time of 12-36 hours; and / or, The conditions for the second impregnation include: a temperature of 20-180°C and a time of 1-10 hours.

10. The preparation method according to any one of claims 3-7, characterized in that, The heating conditions in step (c) include heating at 100-200°C for 10-60 min in a 10-30 vol% H2 / He atmosphere.

11. The bimetallic catalyst prepared by the method according to any one of claims 3-7.

12. The use of a bimetallic catalyst according to any one of claims 1-2 and 11 in the hydroformylation of olefins.

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