A rhodium-based catalyst and its preparation method and application

Abstract

The present invention discloses a rhodium-based catalyst, a preparation method thereof, and an application thereof. The method of the present invention comprises the following steps: (1) placing a functionalized silica gel material in a rhodium-containing solution, adsorbing the material under stirring, filtering, and washing to obtain a rhodium-loaded functionalized silica gel material; (2) preparing graphene oxide; (3) silanizing the graphene oxide obtained in step (2) by a two-step process, mixing the silanized graphene with the rhodium-loaded functionalized silica gel material obtained in step (1), adding a control agent for a first banburying, then adding a vulcanizing agent for a second banburying, and then vulcanizing and forming to obtain a rhodium-based catalyst. The catalyst obtained by the method is used in an olefin hydroformylation reaction, can effectively improve the conversion rate of the reaction, and can also achieve efficient recovery of rhodium in low-concentration rhodium-containing waste liquid, thereby reducing production costs.

Description

Technical Field

[0001] The present invention relates to the field of catalyst preparation, and in particular to a rhodium-based catalyst and a preparation method and application thereof. Background Art

[0002] Olefin hydroformylation, also known as carbonyl synthesis (OXO) reaction, refers to the reaction of olefins with carbon monoxide and hydrogen in the presence of a transition metal complex catalyst to produce normal and isomeric aldehydes with one more carbon atom than the raw olefin.

[0003] Olefin hydroformylation is a typical homogeneous complex catalytic reaction, characterized by high catalytic activity and good selectivity. It is often used industrially to produce aldehydes and alcohols, which are widely used in the fine chemical industry. These aldehydes can be used to synthesize surfactants, textile additives, and plasticizers, as well as various pharmaceutical intermediates for the pharmaceutical industry. Olefin hydroformylation can also be further processed into fragrances for use in the food industry. Olefin hydroformylation is an atom-economic reaction, where all atoms in the synthesis gas are converted into olefins, without generating waste or toxic or harmful substances. It is a recognized green chemical process that meets the requirements of sustainable development and has become a key development area and research area in the chemical industry both domestically and internationally.

[0004] In the mid-1950s, researchers discovered that rhodium was a more active metal than cobalt in hydroformylation reactions. Union Carbide Corporation (UCC) in the United States, Davy Power Gas (DAVY), and Johnson Matthey in the United Kingdom jointly developed an oil-soluble rhodium-phosphine complex catalyst, HRh(CO)(P(Ph3)3). Compared with cobalt-based catalysts, rhodium-based catalysts have lower operating pressures and better safety, resulting in the so-called low-pressure carbonylation process. However, due to the difficulty of catalyst recovery due to the precious metal rhodium, its widespread application was limited.

[0005] China is extremely short of platinum group metal (PGM) mineral resources and reserves. With the rapid development of modern industry and science and technology, PGM consumption has increased significantly. China's rhodium and PGM recycling industry, while starting later than overseas, has developed rapidly. However, this rapid growth also presents numerous challenges. Among them, outdated recycling technology, severe environmental pollution during the refining process, and resource waste are pressing issues that need to be addressed. Summary of the Invention

[0006] In response to the above-mentioned deficiencies in the prior art, the present invention provides a rhodium-based catalyst, a preparation method thereof, and an application thereof. The catalyst obtained by the method is used in an olefin hydroformylation reaction, and can effectively improve the conversion rate of the reaction. At the same time, the rhodium-based catalyst of the present invention is less likely to dissolve in the reaction, thereby reducing the loss of rhodium.

[0007] The first aspect of the present invention provides a method for preparing a rhodium-based catalyst, comprising the following steps:

[0008] (1) placing the functionalized silica gel material in a rhodium-containing solution, adsorbing the rhodium under stirring, and then filtering and washing to obtain a rhodium-loaded functionalized silica gel material;

[0009] (2) Preparation of graphene oxide;

[0010] (3) The graphene oxide obtained in step (2) is silanized by a two-step method, the silanized graphene obtained is mixed with the rhodium-loaded functionalized silica gel material obtained in step (1), a control agent is added for a first banburying, a vulcanizing agent is added for a second banburying, and then the mixture is vulcanized and formed to obtain a rhodium-based catalyst.

[0011] Furthermore, in step (1), the rhodium-containing solution is a conventional rhodium-containing solution in the art, preferably a rhodium-containing waste liquid. In the rhodium-containing solution, the rhodium source is preferably at least one of triphenylphosphine acetylacetonato carbonyl rhodium, rhodium trichloride, rhodium iodide, acetylacetonato carbonyl rhodium, and the like.

[0012] Furthermore, the rhodium-containing waste liquid mainly comes from at least one of rhodium smelting, pharmaceutical and intermediate purification, three-way catalytic converter waste, rhodium-catalyzed organic reaction process flow or waste liquid, etc.

[0013] Furthermore, in step (1), the mass concentration of rhodium in the rhodium-containing solution as an element is 300ppm-2000ppm.

[0014] Furthermore, in step (1), the functionalized silica gel material and its preparation method are described in CN110191911B, the entire contents of which are hereby fully incorporated into the present invention by reference. The functionalized silica gel material has a structure shown in general formula I.

[0015] Furthermore, in step (1), the functionalized silica gel material has a structure shown in general formula I: [Y] y [A] a [B 1 ] 1b [B 2 ] 2b [C 1 ] 1c [C 2 ] 2c [C 3 ] 3c [C 4 ] 4c [D 1 ] 1d [D 2 ] 2d [D 3 ]3d [D 4 ] 4d [D 5 ] 5d [D 6 ] 6d [E] e [F] f [G] g [H] h [J] j [K] k [M] m [P] p [U] u [V] v [W] w [X] x ,

[0016] Where Y is Si(O 4 / 2 ); W is R z R 1 Si(O q / 2 ); X is (O 3 / 2 )SiC3H6SH;

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] Furthermore, in step (1), one of the preparation methods adopted for the functionalized silica gel material is:

[0027] Heat the 1,3-dimercaptopropane and diallylamine solution to 100-140°C, then continue heating for 2-5 hours, adding di-tert-butyl peroxide (5-15 mL) dropwise every 10-20 minutes. Add vinyltrimethoxysilane, and heat the solution at 110-130°C for 2-5 hours, adding di-tert-butyl peroxide (5-15 mL) dropwise every 10-20 minutes, then cool to 50-70°C and add to a stirred mixture of silica gel (6.0 kg, 60-200 μm) and toluene (12-16 L). In addition, N-methyl, N- 1 A solution of 3-(3-(2-triethylsilylethylthio)propylthio)propylthiourea and toluene (70-130 mL) was prepared. The mixture was stirred and refluxed for 0.5-2 hours, followed by the addition of N-3-(3-trimethoxysilylpropylthio)propylthiourea (CH3O)3SiC3H6SC3H6NHC(=S)NH2 (prepared by reacting allylthiourea and trimercaptopropyltrimethoxysilane at 110-140°C for 1-4 hours), followed by further reflux and stirring for 3-6 hours. After cooling, the solid was filtered, washed thoroughly with methanol, and dried to obtain a composition of the general formula I, wherein Y, F, J, M, and U are all present, n is 2, Z in J is C=SNHCH3, and Z in M ​​is hydrogen.

[0028] Furthermore, the molar ratio of the 1,3-dimercaptopropane to diallylamine is 1-2:1. The molar ratio of the vinyltrimethoxysilane to diallylamine is 0.5-1:1. 1 The molar ratio of 3-(3-(2-triethylsilylethylthio)propylthio)propylthiourea to diallylamine is 0.1-0.5:1. The molar ratio of N-3-(3-trimethoxysilylpropylthio)propylthiourea (CH3O)3SiC3H6SC3H6NHC(=S)NH2 to diallylamine is 0.01-0.05:1.

[0029] Furthermore, in step (1), the mass ratio of the functionalized silica gel material to the rhodium in the rhodium-containing solution as an element is 100:1-2:1, preferably 80:1-10:1.

[0030] Furthermore, in step (1), the adsorption conditions are: adsorption at 30-80°C for 2-10 hours.

[0031] Furthermore, in step (1), the washing can be performed by conventional methods in the art, such as washing with ethanol.

[0032] Furthermore, the method for preparing graphene oxide in step (2) specifically includes:

[0033] Concentrated sulfuric acid is placed in a beaker and placed in an ice-water bath. Graphite powder is added and ultrasonically treated. The ultrasonic treatment is turned off, and potassium permanganate is added. The mixture is stirred for a first time for 0.5-5 hours in an ice-water bath. The mixture is then heated to 30-60° C. and stirred for a second time for 0.5-5 hours. The mixture is further heated to 80-100° C. and stirred for a third time. Water is added and the reaction is continued for 0.5-5 hours. The obtained material is cooled and a hydrogen peroxide solution is added until the solution turns bright yellow. The solution is filtered, washed, and the obtained sample is centrifuged, dried, and ground to obtain graphene oxide.

[0034] Furthermore, during the preparation of graphene oxide, the mass concentration of the concentrated sulfuric acid is 80%-98%.

[0035] Furthermore, in the process of preparing graphene oxide, the mass volume ratio of the graphite powder to concentrated sulfuric acid is 1:10-1:100 (g / mL).

[0036] Furthermore, in the process of preparing graphene oxide, the conditions of the ultrasonic treatment are: ultrasonic time is 1h-4h, and ultrasonic frequency is 15-30kHz.

[0037] Furthermore, in the process of preparing graphene oxide, the mass ratio of the graphite powder to potassium permanganate is 1:1-1:10.

[0038] Furthermore, during the preparation of graphene oxide, the first stirring rate is 300 r / min-700 r / min, the second stirring rate is 300 r / min-700 r / min, and the third stirring rate is 200 r / min-500 r / min. Preferably, the third stirring rate is lower than the first stirring rate and the second stirring rate.

[0039] Furthermore, in the process of preparing graphene oxide, after the third stirring, the water added is preferably deionized water, and the volume ratio of the water to concentrated sulfuric acid is 1:1-5:1.

[0040] Furthermore, during the preparation of graphene oxide, the mass concentration of the hydrogen peroxide solution is 25wt%-30wt%.

[0041] Furthermore, during the preparation of graphene oxide, the washing can be carried out by conventional washing methods in the art, such as first washing with a dilute acid solution (such as dilute hydrochloric acid, dilute nitric acid, etc.) until there is no sulfate, and then rinsing with deionized water.

[0042] Furthermore, during the preparation of graphene oxide, the drying conditions are: drying at 60-120° C. for 4-12 hours.

[0043] Furthermore, during the preparation of graphene oxide, the grinding can be performed by grinding into powder using a mortar.

[0044] Furthermore, in step (3), the two-step silanization method specifically includes:

[0045] (i) Graphene oxide was modified using 3-(2-aminoethylamino)propyltrimethoxysilane (AEAPTMS) to obtain the intermediate product AGO;

[0046] (ii) Tetraethyl orthosilicate (TEOS) is then hydrolyzed and condensed on the AGO surface to obtain silanized graphene TGO.

[0047] Furthermore, step (i) is specifically as follows: dispersing the graphene oxide obtained in step (2) in water under ultrasound (the graphene oxide obtained in step (2) and part of the water can be first prepared into a graphene slurry, then ultrasonically dispersed, and finally diluted with an appropriate amount of water), adding 3-(2-aminoethylamino)propyltrimethoxysilane (AEAPTMS), continuing ultrasound for 0.5-3h, and then refluxing at 80-100°C for 2-8h, filtering, washing, and drying to obtain the intermediate product AGO.

[0048] Furthermore, in step (i), the total mass-to-volume ratio of the graphene oxide to water is 1:50-1:500 (g / mL).

[0049] Furthermore, in step (i), the volume mass ratio of the 3-(2-aminoethylamino)propyltrimethoxysilane (AEAPTMS) to the graphene oxide is 1-20 mL / g.

[0050] Furthermore, in step (i), the frequency of the ultrasound is 15-30 kHz.

[0051] Furthermore, in step (i), the washing is performed with water and / or anhydrous ethanol for 2-5 times.

[0052] Furthermore, in step (i), the drying conditions are: drying at 80-120° C. for 4-12 hours.

[0053] Furthermore, in step (ii), the intermediate product AGO is ultrasonically dispersed in anhydrous ethanol, tetraethyl orthosilicate and water are added, and the mixture is stirred at 15-40° C. for 2-8 hours, and then the pH is adjusted to 9-10, and the mixture is stirred at 50-70° C. for 0.5-4 hours, and then stirred at 30-45° C. for 2-8 hours, washed, and dried to obtain silanized graphene TGO.

[0054] Furthermore, in step (ii), the mass volume ratio of the intermediate product AGO to anhydrous ethanol is 1:20-1:500 (g / mL).

[0055] Furthermore, in step (ii), the mass volume ratio of the intermediate product AGO to tetraethyl orthosilicate is 1:1-1:20 (g / mL).

[0056] Furthermore, in step (ii), the mass volume ratio of the intermediate product AGO to water is 1:1-1:20 (g / mL).

[0057] Furthermore, in step (ii), the pH may be adjusted using aqueous ammonia.

[0058] Furthermore, in step (ii), the washing is performed by washing with deionized water and / or ethanol until the mixture becomes neutral.

[0059] Furthermore, in step (ii), the drying condition is: drying at 80-120° C. for 4-12 hours.

[0060] Furthermore, in step (3), the mass ratio of the silanized graphene to the rhodium-loaded functionalized silica gel material is 1:10-1:100, based on the mass of the graphene oxide contained in the silanized graphene.

[0061] Furthermore, in step (3), the control agent is at least one of hydroxy silicone oil, methylphenylmethoxy silicone oil, and polymethylvinylsiloxane, preferably hydroxy silicone oil. The mass ratio of the control agent to the rhodium-loaded functionalized silica gel material is 1:40-1:100.

[0062] Furthermore, in step (3), the vulcanizing agent is at least one of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DBPH), benzoyl peroxide (BP), 2,4-dichlorobenzoyl peroxide (DCBP), tert-butyl perbenzoate (TBPB), and dicumyl peroxide (DCP), preferably 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DBPH). The mass ratio of the vulcanizing agent to the rhodium-loaded functionalized silica gel material is 1:40-1:200.

[0063] Furthermore, in step (3), the conditions for the first banburying are: temperature 60-100°C, time 5-40 min. The conditions for the second banburying are: temperature 60-100°C, time 5-40 min.

[0064] Furthermore, in step (3), the vulcanization conditions are: temperature 120-250°C, time 5-30 minutes.

[0065] The second aspect of the present invention provides a rhodium-based catalyst prepared by the above method.

[0066] Furthermore, in the rhodium-based catalyst, the mass content of rhodium as an element is 2wt%-15wt%.

[0067] The third aspect of the present invention provides a use of a rhodium-based catalyst prepared by the above method in a hydrocarbon hydroformylation reaction.

[0068] Furthermore, the reaction is specifically performed by contacting and reacting C2-C14 olefins with synthesis gas at 60-140°C in the presence of a rhodium-based catalyst. The amount of the rhodium-based catalyst in the reaction system is 100-1500 ppm by mass as rhodium metal. The molar ratio of H2 / CO in the synthesis gas is 3:1-1:3. The preferred molar ratio of synthesis gas to olefin is 1-10:1.

[0069] Compared with the prior art, the present invention has the following advantages:

[0070] 1. The rhodium-based catalyst obtained by the preparation method of the present invention can effectively improve the conversion rate and normal-to-iso ratio of the reaction in the olefin hydroformylation reaction compared with commonly used rhodium catalysts. At the same time, the rhodium-based catalyst of the present invention is less likely to dissolve in the reaction, thereby reducing the loss of rhodium.

[0071] 2. The preparation method of the present invention can also realize the efficient recovery of rhodium from low-concentration rhodium-containing waste liquid, thereby reducing production costs. DETAILED DESCRIPTION

[0072] The technical solutions of the present invention are described in detail below with reference to the embodiments, but the present invention is not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. Example 1

[0073] 40 g of functionalized silica gel material (prepared according to Example 10 in the specification of CN110191911B) was added to 4 L of waste liquid containing 1000 ppm of rhodium, where the rhodium originated from the triphenylphosphine acetylacetonate carbonyl rhodium catalyst used. The mixture was stirred at 30°C for 6 h for adsorption, then filtered and washed with 2000 mL of ethanol to obtain the rhodium-loaded functionalized silica gel material Rh / Si-gel.

[0074] Measure 50mL of 98% sulfuric acid in a beaker and place it in an ice water bath. Add 1g of graphite powder and ultrasonicate for 1 hour at a frequency of 20kHZ. Turn off the ultrasound and add 4g of potassium permanganate. Keep the temperature in an ice bath and stir at 500r / min for 1 hour. Then control the temperature at 40°C and stir at 500r / min for 2 hours. Continue to heat to 80°C and stir at a low speed of 300r / min. Add 150mL of deionized water and continue to react for 0.5 hours. Place the resulting solution at room temperature and add 30wt% hydrogen peroxide solution until the solution turns bright yellow. Filter while hot and rinse with 10wt% dilute hydrochloric acid until there is no SO4. 2- The sample was then washed with deionized water, centrifuged, dried at 110 °C for 8 h, and ground to obtain graphene oxide GO.

[0075] 400 mg of graphene oxide (GO) was placed in a round-bottom flask and deionized water was added to 40 g to prepare a slurry. The slurry was then ultrasonically dispersed at 20 kHz for 1 hour. An appropriate amount of water was added to dilute the slurry to 2 mg / mL. Then, 2 mL of 3-(2-aminoethylamino)propyltrimethoxysilane (AEAPTMS) was added and ultrasonication continued at 20 kHz for 10 minutes. A magnetic stirrer was placed in the slurry and the mixture was refluxed at 98°C in an oil bath for 4 hours. The mixture was then filtered, washed three times with water and anhydrous ethanol, and dried at 80°C for 6 hours to obtain the intermediate product, AGO. The intermediate AGO was then ultrasonically dispersed in 200 mL of anhydrous ethanol. 7.5 mL of tetraethyl orthosilicate (TEOS) and 5 mL of water were added dropwise. A magnetic stirrer was then added and the mixture was stirred at 25°C for 4 hours to fully hydrolyze the Si-OH groups in the TEOS. An appropriate amount of ammonia was then added dropwise to adjust the pH to 9.5. The mixture was stirred in a water bath at 60°C for 2 hours and then at 40°C for another 4 hours. After repeated washing with water and ethanol until neutral, the mixture was placed in a constant temperature drying oven and dried at 80°C for 6 h to obtain silanized graphene oxide TGO.

[0076] 40g of rhodium-loaded functionalized silica gel (Rh / Si-gel) was placed in an internal mixer and stirred at 80 rpm. The silanized graphene oxide (TGO) prepared above was slowly added, along with 0.8g of hydroxy silicone oil. The mixture was then mixed at 80°C for 15 minutes. Then, 0.4g of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DBPH) was added and mixed at 80°C for 15 minutes. After the mixture cooled, it was vulcanized at 170°C for 15 minutes to produce the final, solidified composite product—a rhodium-based catalyst (rhodium content, calculated as elemental weight, 5 wt%). Example 2

[0077] 40 g of functionalized silica gel material (prepared according to Example 3 in the specification of CN110191911B) was added to 8 L of waste liquid containing 700 ppm of rhodium, where the rhodium originated from the rhodium trichloride catalyst used. The mixture was stirred at 50°C for 5 h for adsorption, filtered, and washed with 2000 mL of ethanol to obtain rhodium-loaded functionalized silica gel material Rh / Si-gel.

[0078] Measure 40mL of 98% sulfuric acid in a beaker and place it in an ice water bath. Add 2g of graphite powder and ultrasonicate for 2.5 hours at an ultrasonic frequency of 20kHZ. Turn off the ultrasound and add 6g of potassium permanganate. Keep the temperature in an ice bath and stir at 500r / min for 1.5 hours. Then control the temperature at 40°C and stir continuously at 500r / min for 2 hours. Continue to heat to 95°C and stir at a low speed of 300r / min. Add 150mL of deionized water and continue to react for 3 hours. Place the resulting solution at room temperature and add 30wt% hydrogen peroxide solution until the solution turns bright yellow. Filter while hot and rinse with 10wt% dilute hydrochloric acid until there is no SO4. 2- Then, the sample was washed with deionized water, centrifuged, dried, dried at 110 °C for 8 h, and ground to obtain graphene oxide GO.

[0079] 400 mg of GO was placed in a round-bottom flask and deionized water was added to 40 g to prepare a graphene oxide slurry. The slurry was ultrasonically dispersed at 20 kHz for 1 hour, diluted to 2 mg / mL with water, and then 5 mL of 3-(2-aminoethylamino)propyltrimethoxysilane (AEAPTMS) was added. Ultrasonication was continued for 20 minutes at 20 kHz. A magnetic stirrer was added, and the mixture was refluxed in an oil bath at 90°C for 4 hours. The mixture was filtered and washed three times with water and anhydrous ethanol to obtain the intermediate product, AGO. The AGO was then ultrasonically dispersed again in 200 mL of anhydrous ethanol, and 12 mL of tetraethyl orthosilicate (TEOS) and 5 mL of water were added dropwise. A magnetic stirrer was added and the mixture was stirred at room temperature for 4 hours to fully hydrolyze the Si-OH groups in the TEOS. An appropriate amount of ammonia was then added dropwise to adjust the pH to 9.7. The mixture was stirred in a water bath at 60°C for 4 hours and then at 40°C for another 4 hours. After repeated washing with water and ethanol until neutral, the mixture was placed in a constant temperature drying oven and dried at 80°C for 8 h to obtain silanized graphene oxide TGO.

[0080] 40g of rhodium-loaded functionalized silica gel (Rh / Si-gel) was placed in an internal mixer and stirred at 80 rpm. The silanized graphene oxide (TGO) prepared above was slowly added, along with 1.6g of hydroxy silicone oil. The mixture was then internally mixed at 80°C for 15 minutes. 0.4g of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DBPH) was then added and internally mixed at 80°C for 15 minutes. After the mixture cooled, it was vulcanized at 170°C for 15 minutes to produce the final, solidified composite product—the rhodium-based catalyst (rhodium content, calculated as elemental weight, was 7.2 wt%). Example 3

[0081] 40 g of functionalized silica gel material (prepared according to Example 9 in the specification of CN110191911B) was added to 6 L of waste liquid containing 900 ppm of rhodium, where the rhodium originated from the triphenylphosphine acetylacetonate carbonyl rhodium catalyst used. The mixture was stirred at 60°C for 6 h for adsorption, filtered, and washed with 2000 mL of ethanol to obtain the rhodium-loaded functionalized silica gel material Rh / Si-gel.

[0082] Measure 50mL of 98% sulfuric acid in a beaker and place it in an ice water bath. Add 1g of graphite powder and ultrasonicate for 50min at a frequency of 20kHZ. Turn off the ultrasound and add 4g of potassium permanganate. Keep the temperature in an ice bath and stir at 550r / min for 1 hour. Then control the temperature at 40°C and stir at 550r / min for 2 hours. Continue to heat to 80°C and stir at a low speed of 300r / min. Add 150mL of deionized water and continue to react for 0.5 hours. Place the resulting solution at room temperature and add 30wt% hydrogen peroxide solution until the solution turns bright yellow. Filter while hot and rinse with 10wt% dilute hydrochloric acid until there is no SO4. 2- The sample was then washed with deionized water, centrifuged, dried at 110 °C for 6 h, and ground to obtain graphene oxide GO.

[0083] 400 mg of graphene oxide (GO) was placed in a round-bottom flask and deionized water was added to 40 g to prepare a slurry. The slurry was then ultrasonically dispersed at 20 kHz for 1 hour. An appropriate amount of water was added to dilute the slurry to 2 mg / mL. Then, 2 mL of 3-(2-aminoethylamino)propyltrimethoxysilane (AEAPTMS) was added and ultrasonication continued at 20 kHz for 15 minutes. A magnetic stirrer was placed, and the mixture was refluxed at 98°C in an oil bath for 4 hours. The mixture was then filtered, washed three times with water and anhydrous ethanol, and dried at 90°C for 6 hours to obtain the intermediate product, AGO. The intermediate AGO was then ultrasonically dispersed in 200 mL of anhydrous ethanol. 10 mL of tetraethyl orthosilicate (TEOS) and 7.5 mL of water were added dropwise. A magnetic stirrer was then added, and the mixture was stirred at 25°C for 4 hours to fully hydrolyze the Si-OH groups in the TEOS. An appropriate amount of ammonia was then added dropwise to adjust the pH to 9.7. The mixture was stirred in a 70°C water bath for 2 hours and then at 45°C for another 4 hours. After repeated washing with water and ethanol until neutral, the mixture was placed in a constant temperature drying oven and dried at 90°C for 6 h to obtain silanized graphene oxide TGO.

[0084] 40g of rhodium-loaded functionalized silica gel (Rh / Si-gel) was placed in an internal mixer and stirred at 90 rpm. The silanized graphene oxide (TGO) prepared above was slowly added, along with 0.8g of hydroxy silicone oil. The mixture was mixed at 90°C for 15 minutes. Then, 0.4g of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DBPH) was added and mixed at 80°C for 20 minutes. After the mixture cooled, it was vulcanized at 180°C for 15 minutes to produce the final, solidified composite product, a rhodium-based catalyst (7 wt% rhodium content). Example 4

[0085] 40 g of functionalized silica gel material (prepared according to Example 21 in the specification of CN110191911B) was added to 10 L of waste liquid containing 700 ppm of rhodium, where the rhodium originated from the rhodium trichloride catalyst used. The mixture was stirred at 75°C for 5 h for adsorption, filtered, and washed with 2000 mL of ethanol to obtain rhodium-loaded functionalized silica gel material Rh / Si-gel.

[0086] Measure 40mL of 98% sulfuric acid in a beaker and place it in an ice water bath. Add 2g of graphite powder and ultrasonicate for 3 hours at an ultrasonic frequency of 20kHZ. Turn off the ultrasound and add 6g of potassium permanganate. Keep the temperature in an ice bath and stir at 600r / min for 1.5 hours. Then control the temperature at 45°C and stir continuously at 600r / min for 2 hours. Continue to heat to 95°C and stir at a low speed of 300r / min. Add 150mL of deionized water and continue to react for 3 hours. Place the resulting solution at room temperature and add 30wt% hydrogen peroxide solution until the solution turns bright yellow. Filter while hot and rinse with 10wt% dilute hydrochloric acid until there is no SO4. 2- Then, the sample was washed with deionized water, centrifuged, dried, dried at 100 °C for 8 h, and ground to obtain graphene oxide GO.

[0087] 400 mg of GO was placed in a round-bottom flask and deionized water was added to 40 g to prepare a graphene oxide slurry. The slurry was ultrasonically dispersed at 20 kHz for 1 hour, diluted to 2 mg / mL with an appropriate amount of water, and then 4 mL of 3-(2-aminoethylamino)propyltrimethoxysilane (AEAPTMS) was added. Ultrasonication was continued for 20 minutes at a frequency of 20 kHz. A magnetic stirrer was added, and the mixture was refluxed in an oil bath at 90°C for 6 hours. The mixture was then filtered and washed three times with water and anhydrous ethanol to obtain the intermediate product, AGO. The AGO was then ultrasonically dispersed again in 200 mL of anhydrous ethanol, and 12 mL of tetraethyl orthosilicate (TEOS) and 8 mL of water were added dropwise. A magnetic stirrer was then added and stirred at room temperature for 4 hours to fully hydrolyze the Si-OH groups in the TEOS. An appropriate amount of ammonia was then added dropwise to adjust the pH to 9.9. The mixture was stirred in a water bath at 60°C for 4 hours and then at 40°C for another 4 hours. After repeated washing with water and ethanol until neutral, the mixture was placed in a constant temperature drying oven and dried at 80°C for 8 h to obtain silanized graphene oxide TGO.

[0088] 40g of rhodium-loaded functionalized silica gel (Rh / Si-gel) was placed in an internal mixer and stirred at 70 rpm. The silanized graphene oxide (TGO) prepared above was slowly added, along with 1.6g of hydroxy silicone oil. The mixture was internally kneaded at 80°C for 15 minutes. 0.4g of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (DBPH) was then added and internally kneaded at 90°C for 20 minutes. After the mixture cooled, it was vulcanized at 200°C for 15 minutes to produce the final, solidified composite product—a rhodium-based catalyst (rhodium content, calculated as elemental weight, 10 wt%)—in a sheet form.

[0089] Comparative Example 1

[0090] Compared with Example 1, the only difference is that 40 g of functionalized silicone rubber is replaced with conventional commercially available fluorosilicone rubber. Other components are the same as in Example 1. Finally, a rhodium-based catalyst is prepared. Example 5

[0091] Propylene, synthesis gas, triphenylphosphine and the rhodium-based catalyst obtained in Example 1 (the solvent is n-hexane, and the amount of the rhodium-based catalyst in the solution is 300 ppm as metallic rhodium) are placed in an autoclave, wherein the reaction is carried out at T = 90° C., r = 300 r / min, H2 / CO molar ratio = 1:1, and the feed molar ratio of synthesis gas to propylene is maintained at 2:1. After the reaction is carried out for 4 hours, the reaction is stopped and the temperature is lowered. After the reaction product reaches room temperature, it is taken out and detected by chromatography, which shows that the conversion rate of propylene reaches 97%, the yield of the product n-butyraldehyde is 94.7%, and the normal isomer ratio is 42:1. Example 6

[0092] Compared with Example 5, the only difference is that the catalyst used is the rhodium-based catalyst obtained in Example 2. Chromatographic detection shows that the conversion rate of propylene reaches 98%, the yield of the product n-butyraldehyde is 95.6%, and the n-isomer ratio is 40:1. Example 7

[0093] Isobutylene, synthesis gas, triphenylphosphine and the rhodium-based catalyst obtained in Example 3 (the solvent is n-hexane, and the amount of the rhodium-based catalyst in the solution is 300 ppm as metallic rhodium) are placed in an autoclave, wherein the reaction is carried out at T = 90° C., r = 300 r / min, H2 / CO molar ratio = 1:1, and the feed molar ratio of synthesis gas to isobutylene is maintained at 2:1. After reacting for 4 hours, the reaction is stopped and the temperature is lowered. After the reaction product reaches room temperature, it is taken out and detected by chromatography, which shows that the conversion rate of isobutylene reaches 98.9%, and the yield of the product isovaleraldehyde is 98%. Example 8

[0094] Compared with Example 7, the only difference is that the catalyst used is the rhodium-based catalyst obtained in Example 4. Chromatographic detection shows that the conversion rate of isobutylene reaches 98.1%, and the yield of the product isovaleraldehyde is 97.6%.

[0095] Comparative Example 2

[0096] Propylene, synthesis gas, triphenylphosphine and rhodium parker (the solvent is n-hexane, and the amount of rhodium compound in the solution is 300 ppm as metallic rhodium) are put into a high-pressure reactor, wherein, at T=90°C, r=300r / min, H2 / CO molar ratio=1:1, the feed molar ratio of synthesis gas to propylene is maintained at 2:1. After the reaction is stopped and the temperature is lowered after 4 hours, the reaction is taken out after reaching room temperature, and the reaction product is detected by chromatography, which shows that the conversion rate of propylene reaches 82.9%, the yield of the product n-butyraldehyde is 77.7%, and the normal isomer ratio is 15:1.

[0097] Comparative Example 3

[0098] Isobutylene, synthesis gas, triphenylphosphine and rhodium pike (the solvent is n-hexane, and the amount of rhodium compound in the solution is 300 ppm as metallic rhodium) are put into a high-pressure reactor, wherein, at T=90°C, r=300r / min, H2 / CO molar ratio=1:1, the feed molar ratio of synthesis gas to isobutylene is maintained at 2:1. After the reaction is carried out for 4 hours, the reaction is stopped and the temperature is lowered. After the reaction product reaches room temperature, it is taken out and detected by chromatography, and it can be found that the conversion rate of isobutylene reaches 74.8%, and the yield of isovaleraldehyde is 73.2%.

[0099] Comparative Example 4

[0100] Propylene, synthesis gas, triphenylphosphine and the rhodium-based catalyst prepared in Comparative Example 1 (the solvent is n-hexane, and the amount of the rhodium-based catalyst in the solution is 300 ppm as metallic rhodium) are put into a high-pressure reactor, wherein, at T=90°C, r=300 r / min, H2 / CO molar ratio=1:1, and the feed molar ratio of synthesis gas to propylene is maintained at 2:1. After the reaction is allowed to proceed for 4 hours, the reaction is stopped and the temperature is lowered. After the reaction product reaches room temperature, it is taken out and detected by chromatography, which shows that the conversion rate of propylene reaches 79.9%, the yield of the product n-butyraldehyde is 77.3%, and the normal isomer ratio is 30:1. Example 9

[0101] The solutions after the reaction in Example 5 and Example 7 were taken for detection of rhodium element by atomic absorption spectroscopy. The rhodium content of the reaction solution in Example 5 was 21 ppm, and the rhodium content of the reaction solution in Example 7 was 20 ppm.

[0102] Comparative Example 5

[0103] The solutions after the reactions in Comparative Example 2, Comparative Example 3 and Comparative Example 4 were subjected to atomic absorption detection of rhodium. The rhodium content of the reaction solution in Comparative Example 2 was 65 ppm, the rhodium content of the reaction solution in Comparative Example 3 was 70 ppm, and the rhodium content of the reaction solution in Comparative Example 4 was 77 ppm.

[0104] The above describes in detail the specific embodiments of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for preparing a rhodium-based catalyst, characterized in that: The following steps are involved: (1) placing the functionalized silica gel material in a rhodium-containing solution, adsorbing the rhodium under stirring, and then filtering and washing to obtain a rhodium-loaded functionalized silica gel material; (2) Preparation of graphene oxide; (3) silanizing the graphene oxide obtained in step (2) by a two-step process, mixing the obtained silanized graphene with the rhodium-loaded functionalized silica gel material obtained in step (1), adding a control agent for a first banburying, then adding a vulcanizing agent for a second banburying, and then vulcanizing and molding to obtain a rhodium-based catalyst; In step (3), the two-step silanization method specifically includes: (i) Graphene oxide was modified using 3-(2-aminoethylamino)propyltrimethoxysilane to obtain the intermediate product AGO; (ii) Tetraethyl orthosilicate is then hydrolyzed and condensed on the surface of AGO to obtain silanized graphene TGO; In step (3), the mass ratio of the silanized graphene to the rhodium-loaded functionalized silica gel material is 1:10-1:100, based on the mass of the graphene oxide contained therein; And / or, in step (3), the control agent is at least one of hydroxy silicone oil, methylphenylmethoxy silicone oil, and polymethylvinylsiloxane; the mass ratio of the control agent to the rhodium-loaded functionalized silica gel material is 1:40-1:100; And / or, in step (3), the vulcanizing agent is at least one of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl perbenzoate, and diisopropylbenzene peroxide; and the mass ratio of the vulcanizing agent to the rhodium-loaded functionalized silica gel material is 1:40-1:200; And / or, in step (3), the conditions for the first banburying are: temperature 60-100°C, time 5-40 min; the conditions for the second banburying are: temperature 60-100°C, time 5-40 min; And / or, in step (3), the vulcanization conditions are: temperature 120-250° C., time 5-30 minutes.

2. The preparation method according to claim 1, wherein: In step (1), the rhodium-containing solution is a rhodium-containing waste liquid; in the rhodium-containing solution, the rhodium source is at least one of triphenylphosphine acetylacetonate carbonyl rhodium, rhodium trichloride, rhodium iodide, and acetylacetonate carbonyl rhodium; And / or, the mass concentration of rhodium in the rhodium-containing solution as an element is 300ppm-2000ppm.

3. The preparation method according to claim 1, wherein: In step (1), the mass ratio of the functionalized silica gel material to the rhodium in the rhodium-containing solution is 100:1-2:

1.

4. The preparation method according to claim 3, wherein: In step (1), the mass ratio of the functionalized silica gel material to the rhodium in the rhodium-containing solution is 80:1-10:

1.

5. The preparation method according to claim 1, wherein: The method for preparing graphene oxide in step (2) specifically includes: Concentrated sulfuric acid is placed in a beaker and placed in an ice-water bath. Graphite powder is added and ultrasonically treated. The ultrasonic treatment is turned off, and potassium permanganate is added. The mixture is stirred for a first time for 0.5-5 hours in an ice-water bath. The mixture is then heated to 30-60° C. and stirred for a second time for 0.5-5 hours. The mixture is further heated to 80-100° C. and stirred for a third time. Water is added and the reaction is continued for 0.5-5 hours. The obtained material is cooled and a hydrogen peroxide solution is added until the solution turns bright yellow. The solution is filtered, washed, and the obtained sample is centrifuged, dried, and ground to obtain graphene oxide.

6. The preparation method according to claim 1, wherein: Step (i) specifically comprises: dispersing the graphene oxide obtained in step (2) in water under ultrasound, adding 3-(2-aminoethylamino)propyltrimethoxysilane, continuing ultrasound for 0.5-3 hours, then refluxing at 80-100° C. for 2-8 hours, filtering, washing, and drying to obtain the intermediate product AGO; And / or, in step (i), the total mass-to-volume ratio of the graphene oxide to water is 1:50-1:500, wherein the unit of mass is g and the unit of volume is mL; And / or, in step (i), the volume-to-mass ratio of the 3-(2-aminoethylamino)propyltrimethoxysilane to the graphene oxide is 1-20, wherein the unit of mass is g and the unit of volume is mL.

7. The preparation method according to claim 1, wherein: In step (ii), the intermediate product AGO is ultrasonically dispersed in anhydrous ethanol, tetraethyl orthosilicate and water are added, and the mixture is stirred at 15-40° C. for 2-8 hours, and then the pH is adjusted to 9-10, and the mixture is stirred at 50-70° C. for 0.5-4 hours, and then at 30-45° C. for 2-8 hours, washed, and dried to obtain silanized graphene TGO; and / or, in step (ii), the mass-to-volume ratio of the intermediate product AGO to anhydrous ethanol is 1:20-1:500, wherein the unit of mass is g and the unit of volume is mL; and / or, in step (ii), the mass-to-volume ratio of the intermediate product AGO to tetraethyl orthosilicate is 1:1-1:20, wherein the unit of mass is g and the unit of volume is mL; And / or, in step (ii), the mass volume ratio of the intermediate product AGO to water is 1:1-1:20, wherein the unit of mass is g and the unit of volume is mL.

8. A rhodium-based catalyst prepared according to any one of claims 1 to 7.

9. Use of a rhodium-based catalyst prepared according to any one of claims 1 to 7 in hydrocarbon hydroformylation.

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