Preparation method and application of hydrotalcite-loaded modified ruthenium-based catalyst

Abstract

The invention discloses a preparation method and application of a hydrotalcite-loaded modified ruthenium-based catalyst, and belongs to the technical field of catalyst preparation, and the preparation method comprises the following steps: preparing a hydrotalcite carrier; adding the hydrotalcite carrier into isobutanol, and uniformly dispersing; mixing anhydrous ruthenium chloride, aluminum nitrate nonahydrate and cerium nitrate hexahydrate, adding the mixture, and uniformly dispersing; heating to 40-100 DEG C, aging for 1-10 hours, and stirring at a constant temperature until the solvent is completely volatilized; grinding to obtain a powdery solid; gradually heating the powdery solid to 200-500 DEG C in a nitrogen atmosphere, roasting for 2-8 hours, introducing hydrogen, adjusting the temperature to 200-600 DEG C, and reducing at constant temperature for 1-6 hours; and after the reduction is finished, cooling to normal temperature in a nitrogen atmosphere to obtain the hydrotalcite-loaded modified ruthenium-based catalyst. The hydrotalcite-loaded modified ruthenium-based catalyst prepared by the preparation method provided by the invention is high in stability, and has the advantages that the active components are not easy to lose, the service life is long, the selectivity is high, the reaction product is easy to separate, and the like.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst preparation, and in particular to a preparation method and application of a hydrotalcite-loaded modified ruthenium-based catalyst. Background Art

[0002] 1,3-cyclohexylenediamine (1,3-BAC or HXDA) is an important organic chemical and fine chemical intermediate. At present, the mainstream preparation method of 1,3-BAC is the hydrogenation method of meta-xylylenediamine (MXDA). When meta-xylylenediamine is used for hydrogenation reaction, a large amount of inorganic base or ammonia water is usually required to suppress the occurrence of side reactions such as deamination and condensation in the reaction system. The active components of existing catalysts are easy to agglomerate or leach during the reaction, resulting in reduced catalytic activity and service life, making the catalyst unstable and inefficient. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a preparation method and application of a hydrotalcite-supported modified ruthenium-based catalyst, and the specific technical solution is:

[0004] The present invention provides a method for preparing a hydrotalcite-supported modified ruthenium-based catalyst, comprising the following steps:

[0005] Step 1: Mix lanthanum nitrate hexahydrate and zinc nitrate hexahydrate in a mass ratio of 1:(1.5-15), add into deionized water, and disperse evenly;

[0006] Step 2: adding sodium hydroxide and sodium carbonate in a mass ratio of 1: (0.5-2) to the mixture obtained in step 1 and dispersing them evenly;

[0007] Step 3: After the reaction is completed, centrifugation is performed to obtain a solid product, and the solid product is dried and ground to obtain a hydrotalcite carrier;

[0008] Step 4: Add the hydrotalcite carrier into 20-100 ml of isobutanol and stir to disperse evenly;

[0009] Step 5: Mix 1% to 20% of anhydrous ruthenium chloride by mass of the hydrotalcite carrier, aluminum nitrate nonahydrate and cerium nitrate hexahydrate in a mass ratio of (1 to 20):22, and add the mixture obtained in step 4 to disperse evenly;

[0010] Step 6: Raise the temperature to 40-100°C, age for 1-10 hours, and then stir at a constant temperature until all the solvent evaporates;

[0011] Step 7: Grind the product obtained in step 6 to obtain a powdery solid;

[0012] Step 8: gradually heating the powdered solid to 200-500° C. in a nitrogen atmosphere, calcining for 2-8 hours, introducing hydrogen, adjusting the temperature to 200-600° C. and performing constant temperature reduction for 1-6 hours;

[0013] Step 9: After the reduction is completed, the temperature is lowered to room temperature in a nitrogen atmosphere to obtain the hydrotalcite-supported modified ruthenium-based catalyst.

[0014] Preferably:

[0015] In step 1, the dispersion method is ultrasonic dispersion first and then stirring dispersion, and the stirring dispersion time is 10 to 60 minutes;

[0016] The dispersion process in step 2 includes: first stirring and dispersing for 10 to 60 minutes, then moving into a fume hood, and reflux stirring in an oil bath;

[0017] In step 4, the stirring method is magnetic stirring, and the stirring time is 10 to 30 minutes.

[0018] Preferably, the addition process of sodium hydroxide and sodium carbonate in step 2 comprises:

[0019] Add sodium hydroxide and sodium carbonate in a mass ratio of 1:(0.5-2) into deionized water and disperse them evenly to form a mixed solution;

[0020] The mixed solution is added dropwise to the mixture obtained in step 1.

[0021] Preferably, the centrifugal separation process in step 3 includes: transferring the mixture obtained in step 2 into a centrifuge tube, and centrifuging at a rotation speed of 3000 to 8000 rpm for 5 to 20 minutes.

[0022] Preferably, step 5 specifically includes the following sub-steps:

[0023] Step 5.1: Add 1% to 20% of anhydrous ruthenium chloride by mass of the hydrotalcite carrier, aluminum nitrate nonahydrate and cerium nitrate hexahydrate in a mass ratio of (1 to 20):22 into deionized water, and stir magnetically for 10 to 30 minutes;

[0024] Step 5.2: Under stirring, add the mixed solution obtained in step 5.1 dropwise to the mixture obtained in step 4, and stir magnetically for 10 to 30 minutes after the addition.

[0025] Preferably, the reflux stirring time is 2 to 20 hours.

[0026] Preferably, in step 3, the drying temperature is 80-150° C. and the drying time is 5-20 hours.

[0027] Preferably, the step of gradually heating the powdered solid to 200-500° C. in a nitrogen atmosphere in step 8 specifically comprises: placing the powdered solid in a quartz boat, placing the boat in a vacuum tube furnace, introducing high-purity nitrogen with a purity of >99.999% at a flow rate of 35-90 mL / min, and heating the mixture to 200-500° C. at a heating rate of 4-10° C. / min using a programmed temperature increase.

[0028] The present invention also provides an application of a hydrotalcite-supported modified ruthenium-based catalyst, wherein the hydrotalcite-supported modified ruthenium-based catalyst described in any one of the above is used to catalyze the hydrogenation reaction of m-xylylenediamine to prepare 1,3-cyclohexylenediamine, and the preparation process comprises:

[0029] Adding the hydrotalcite-supported modified ruthenium-based catalyst, a polar solvent and m-xylylenediamine into an autoclave, wherein the mass of the hydrotalcite-supported modified ruthenium-based catalyst is 1% to 20% of the mass of the m-xylylenediamine;

[0030] The reactor was sealed, and nitrogen was introduced to replace the air in the reactor 3 to 6 times;

[0031] The reactor is evacuated, then heated to 60-200°C, hydrogen is introduced and pressurized to 1-10 MPa;

[0032] After stirring for 1 to 10 hours, the mixed liquid in the reaction kettle is filtered to obtain the 1,3-cyclohexanedimethylamine.

[0033] Preferably, the polar solvent is at least one of tetrahydrofuran, 1,4-dioxane, isopropanol and dimethyl sulfoxide.

[0034] The preparation method and application of the hydrotalcite-supported modified ruthenium-based catalyst provided by the present invention have the following beneficial effects:

[0035] 1. Strong stability, and has the advantages of active components not easy to lose, long service life, high selectivity, and easy separation of products after reaction;

[0036] 2. The preparation process is simple and the hydrogenation reaction conditions are mild;

[0037] 3. The yield is over 99.0%, which is much higher than the catalyst reported in the market. After separation and purification, 1,3-BAC with a purity of >99.5% can be obtained;

[0038] 4. Ruthenium modified by Ce and Al promotes the dispersion of active metal centers, introduces alkaline center active sites, and reduces the formation of by-products, thereby showing excellent catalytic hydrogenation activity and selectivity for MXDA hydrogenation to 1,3-BAC. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

[0040] This embodiment provides a method for preparing a hydrotalcite-supported ruthenium-based catalyst, comprising the following steps:

[0041] Step 1: Mix lanthanum nitrate hexahydrate and zinc nitrate hexahydrate in a mass ratio of 1:(1.5-15), add into deionized water, and disperse evenly.

[0042] Step 2: Add sodium hydroxide and sodium carbonate in a mass ratio of 1: (0.5-2) to the mixture obtained in step 1 and disperse evenly.

[0043] Step 3: After the reaction is completed, centrifuge to obtain a solid product, and then dry and grind the solid product to obtain a hydrotalcite carrier.

[0044] Step 4: Add the hydrotalcite carrier into 20-100 ml of isobutanol and stir to disperse evenly.

[0045] Step 5: Mix 1% to 20% of anhydrous ruthenium chloride by mass of the hydrotalcite carrier, aluminum nitrate nonahydrate and cerium nitrate hexahydrate in a mass ratio of (1 to 20):22, and add to the mixture obtained in step 4 to disperse evenly.

[0046] Step 6: Raise the temperature to 40-100°C, age for 1-10 hours, and then stir at a constant temperature until all the solvent evaporates.

[0047] Step 7: Grind the product obtained in step 6 to obtain a powdery solid.

[0048] Step 8: gradually raise the temperature of the powdered solid to 200-500° C. in a nitrogen atmosphere, introduce hydrogen after roasting for 2-8 hours, adjust the temperature to 200-600° C. and carry out constant temperature reduction for 1-6 hours.

[0049] Step 9: After the reduction is completed, the temperature is lowered to room temperature under a nitrogen atmosphere to obtain a hydrotalcite-supported modified ruthenium-based catalyst.

[0050] The hydrotalcite-supported ruthenium-based catalyst prepared by the preparation method provided in this embodiment has the following beneficial effects:

[0051] It has strong stability, and has the advantages of active components not being easy to lose, long service life, high selectivity, and easy separation of products after reaction.

[0052] Further:

[0053] The dispersion method in step 1 is ultrasonic dispersion first and then stirring dispersion, and the stirring dispersion time is 10 to 60 minutes.

[0054] The dispersion process in step 2 includes: first stirring and dispersing for 10 to 60 minutes, then moving into a fume hood, and reflux stirring in an oil bath.

[0055] In step 4, the stirring method is magnetic stirring, and the stirring time is 10 to 30 minutes.

[0056] Further, the addition process of sodium hydroxide and sodium carbonate in step 2 includes:

[0057] Sodium hydroxide and sodium carbonate in a mass ratio of 1: (0.5-2) are added into deionized water and dispersed evenly to form a mixed solution.

[0058] The mixed solution was added dropwise to the mixture obtained in step 1.

[0059] Furthermore, the centrifugal separation process in step 3 includes: transferring the mixture obtained in step 2 into a centrifuge tube, and centrifuging at a rotation speed of 3000 to 8000 rpm for 5 to 20 minutes.

[0060] Furthermore, step 5 specifically includes the following sub-steps:

[0061] Step 5.1: Add 1% to 20% of anhydrous ruthenium chloride by mass of the hydrotalcite carrier, aluminum nitrate nonahydrate and cerium nitrate hexahydrate in a mass ratio of (1 to 20):22 into deionized water, and stir magnetically for 10 to 30 minutes.

[0062] Step 5.2: Under stirring, add the mixed solution obtained in step 5.1 dropwise to the mixture obtained in step 4, and stir magnetically for 10 to 30 minutes after the addition.

[0063] Furthermore, the reflux stirring time is 2 to 20 hours.

[0064] Furthermore, in step 3, the drying temperature is 80-150° C., and the drying time is 5-20 hours.

[0065] Furthermore, in step 8, gradually heating the powdered solid to 200-500° C. in a nitrogen atmosphere specifically includes: placing the powdered solid in a quartz boat, placing it in a vacuum tube furnace, introducing high-purity nitrogen with a purity of >99.999% at a flow rate of 35-90 mL / min, and using programmed temperature to heat the mixture to 200-500° C. at a heating rate of 4-10° C. / min.

[0066] This embodiment also provides an application of a hydrotalcite-supported modified ruthenium-based catalyst, using the hydrotalcite-supported modified ruthenium-based catalyst as described in any one of the above to catalyze the hydrogenation reaction of m-xylylenediamine to prepare 1,3-cyclohexylenediamine, and the preparation process includes:

[0067] A hydrotalcite-supported modified ruthenium-based catalyst, a polar solvent and meta-xylylenediamine are added into an autoclave, wherein the mass of the hydrotalcite-supported modified ruthenium-based catalyst is 1% to 20% of the mass of the meta-xylylenediamine.

[0068] The reactor was sealed and nitrogen was introduced to replace the air in the reactor 3 to 6 times.

[0069] The reactor is evacuated, then heated to 60-200°C, hydrogen is introduced and pressurized to 1-10 MPa.

[0070] After stirring for 1 to 10 hours, the mixed liquid in the reaction kettle is filtered to obtain 1,3-cyclohexanedimethylamine.

[0071] The ruthenium-based catalyst supported and modified by hydrotalcite provided in this embodiment has the following beneficial effects in catalyzing the hydrogenation reaction of m-xylylenediamine to prepare 1,3-cyclohexylenediamine:

[0072] 1. The preparation process is simple and the hydrogenation reaction conditions are mild.

[0073] 2. The yield is over 99.0%, which is much higher than the catalyst reported in the market. After separation and purification, 1,3-BAC with a purity of >99.5% can be obtained.

[0074] 3. Ruthenium modified by Ce and Al promotes the dispersion of active metal centers, introduces alkaline center active sites, and reduces the formation of by-products, thereby showing excellent catalytic hydrogenation activity and selectivity for MXDA hydrogenation to 1,3-BAC.

[0075] Furthermore, the polar solvent is at least one of tetrahydrofuran, 1,4-dioxane, isopropanol, and dimethyl sulfoxide.

[0076] The following specific examples are provided, which can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. In the following examples, the ruthenium-based catalyst modified by hydrotalcite support is recorded as Ce-Al-Ru / ZnLa.

[0077] Embodiment 1

[0078] Weigh 3.57 g of lanthanum nitrate hexahydrate and 8.45 g of zinc nitrate hexahydrate into a single-necked round-bottom flask, add 40 ml of deionized water to dissolve, first ultrasonicate for 10 min, then stir and disperse for 15 min, weigh 1.76 g of sodium hydroxide and 1.59 g of sodium carbonate, add 50 ml of deionized water to dissolve, and after dissolution, add them dropwise to the metal salt solution, stir and disperse for 20 min, react in an oil bath in a fume hood, and reflux with stirring for 12 h.

[0079] After the reaction is completed, the reaction solution is transferred to a 50 ml centrifuge tube and centrifuged at 4500 rpm for 5 min. The solid substance obtained after centrifugation is spread evenly in a mortar and dried in a vacuum drying oven at 105°C for 12 h. The dried solid substance is fully ground to obtain a ZnLa hydrotalcite carrier.

[0080] Weigh 2 g of ZnLa hydrotalcite carrier and place it in a round-bottom flask, add 40 ml of isobutanol to dissolve, stir and disperse for 15 minutes, weigh 0.05 g of anhydrous ruthenium chloride, 0.89 g of aluminum nitrate nonahydrate, 1.45 g of cerium nitrate hexahydrate and 40 ml of deionized water and add them to the round-bottom flask, stir magnetically for 15 minutes, add the metal salt solution dropwise to the ZnLa hydrotalcite carrier-isobutanol solution, disperse while adding dropwise, stir magnetically for 10 minutes, operate at 60°C under a fume hood, react in an oil bath, and age for 6 hours. After the aging is completed, remove the reflux seal device, continue stirring at 60°C for 8 hours, until the solvent is completely evaporated, and spread the catalyst in a mortar and grind it thoroughly. The powdered solid obtained above was placed in a quartz boat, which was then placed in a vacuum tube furnace. High-purity nitrogen with a purity of >99.999% was introduced at a flow rate of 35 mL / min, and the temperature was raised from 25°C to 350°C at a rate of 5°C / min. The mixture was calcined at a constant temperature of 350°C for 4 hours. 0.2 g of the powdered substance obtained after the calcination was weighed and placed in a quartz boat, which was then placed in a vacuum tube furnace. The temperature was raised to the reduction temperature at a rate of 5°C / min under nitrogen protection, and the mixture was reduced with hydrogen at 350°C for 2 hours. After the reduction was completed, the temperature was lowered to room temperature under nitrogen protection to obtain a formed Ce-Al-Ru / ZnLa catalyst.

[0081] Weigh 0.1 g of Ce-Al-Ru / ZnLa catalyst and place it in a 50 mL liner of a micro-autoclave, add 15 mL of isobutanol, 1.5 g of m-xylenediamine, put in a magnet, seal the autoclave, replace the air in the autoclave with nitrogen 4 times, evacuate the autoclave with a vacuum pump, and then press and hold the heating button to start heating. When the set reaction temperature of 100°C is reached, hydrogen is introduced and pressurized to 2.5 MPa, the stirring button is pressed and the reaction timing starts. After 3 hours of reaction, the reaction is terminated, the reaction mixture is filtered, and the content of each substance in the filtrate is analyzed by gas chromatography. The conversion rate of m-xylenediamine is 98.9%, and the selectivity of 1,3-cyclohexanedimethylamine is 97.8%.

[0082] Embodiment 2

[0083] Weigh 4.66 g of lanthanum nitrate hexahydrate and 9.55 g of zinc nitrate hexahydrate into a single-necked round-bottom flask, add 40 ml of deionized water to dissolve, first ultrasonicate for 10 min, then stir and disperse for 15 min, weigh 1.76 g of sodium hydroxide and 1.59 g of sodium carbonate, add 50 ml of deionized water to dissolve, and after dissolution, add them dropwise to the metal salt solution, stir and disperse for 20 min, react in an oil bath in a fume hood, and reflux with stirring for 12 h.

[0084] After the reaction is completed, the reaction solution is transferred to a 50 ml centrifuge tube and centrifuged at 4500 rpm for 5 min. The solid substance obtained after centrifugation is spread evenly in a mortar and dried in a vacuum drying oven at 105°C for 12 h. The dried solid substance is fully ground to obtain a ZnLa hydrotalcite carrier.

[0085] Weigh 2 g of ZnLa hydrotalcite carrier and place it in a round-bottom flask, add 40 ml of isobutanol to dissolve, stir and disperse for 15 minutes, weigh 0.08 g of anhydrous ruthenium chloride, 0.89 g of aluminum nitrate nonahydrate, 1.45 g of cerium nitrate hexahydrate and 40 ml of deionized water and add them to the round-bottom flask, stir magnetically for 15 minutes, add the metal salt solution dropwise to the ZnLa hydrotalcite carrier-isobutanol solution, disperse while adding dropwise, stir magnetically for 10 minutes, operate at 60°C under a fume hood, react in an oil bath, and age for 6 hours. After the aging is completed, remove the reflux seal device, continue stirring at 60°C for 8 hours, until the solvent is completely evaporated, and spread the catalyst in a mortar and grind it thoroughly. The powdered solid obtained above was placed in a quartz boat, which was then placed in a vacuum tube furnace. High-purity nitrogen with a purity of >99.999% was introduced at a flow rate of 35 mL / min, and the temperature was raised from 25°C to 350°C at a rate of 5°C / min. The mixture was calcined at a constant temperature of 350°C for 4 hours. 0.2 g of the powdered substance obtained after the calcination was weighed and placed in a quartz boat, which was then placed in a vacuum tube furnace. The temperature was raised to the reduction temperature at a rate of 5°C / min under nitrogen protection, and the mixture was reduced with hydrogen at 350°C for 2 hours. After the reduction was completed, the temperature was lowered to room temperature under nitrogen protection to obtain a formed Ce-Al-Ru / ZnLa catalyst.

[0086] Weigh 0.12 g of Ce-Al-Ru / ZnLa catalyst and place it in a 50 mL liner of a micro-autoclave, add 15 mL of isobutanol, 1.5 g of m-xylenediamine, put in a magnet, seal the autoclave, replace the air in the autoclave with nitrogen 4 times, evacuate the autoclave to vacuum with a vacuum pump, and then press and hold the heating button to start heating. When the set reaction temperature of 110°C is reached, hydrogen is introduced and pressurized to 3.0 MPa, the stirring button is pressed and the reaction timing starts. After 3 hours of reaction, the reaction is terminated, the reaction mixture is filtered, and the content of each substance in the filtrate is analyzed by gas chromatography. The conversion rate of m-xylenediamine is 100%, and the selectivity of 1,3-cyclohexanedimethylamine is 99.6%.

[0087] Comparative Example

[0088] Take 3.88g of lanthanum nitrate hexahydrate and 7.36g of zinc nitrate hexahydrate and put them into a single-mouth round-bottom flask, add 40ml of deionized water to dissolve, first ultrasonicate for 10min, then stir and disperse for 15min, weigh 1.76g of sodium hydroxide and 1.59g of sodium carbonate, add 50ml of deionized water to dissolve, and after dissolution, add them dropwise to the metal salt solution, stir and disperse for 20min, react in an oil bath in a fume hood, and reflux and stir for 12h.

[0089] After the reaction is completed, the reaction solution is transferred to a 50 ml centrifuge tube and centrifuged at 4500 rpm for 5 min. The solid substance obtained after centrifugation is spread evenly in a mortar and dried in a vacuum drying oven at 105°C for 12 h. The dried solid substance is fully ground to obtain a ZnLa hydrotalcite carrier.

[0090] Weigh 2 g of ZnLa hydrotalcite carrier and place it in a round-bottom flask, add 40 ml of isobutanol to dissolve, stir and disperse for 15 minutes, weigh 0.08 g of anhydrous ruthenium chloride, add 40 ml of deionized water to the round-bottom flask, stir magnetically for 15 minutes, add the ruthenium chloride solution dropwise to the ZnLa hydrotalcite carrier-isobutanol solution, disperse while adding dropwise, stir magnetically for 10 minutes, operate at 60°C under a fume hood, react in an oil bath, and age for 7 hours. After the aging is completed, remove the reflux seal device, continue stirring at 60°C for 8 hours, until the solvent is completely evaporated, and spread the catalyst in a mortar and grind it thoroughly. The powdered solid obtained above was placed in a quartz boat, which was then placed in a vacuum tube furnace. High-purity nitrogen with a purity of >99.999% was introduced at a flow rate of 35 mL / min, and the temperature was raised from 25°C to 350°C at a rate of 5°C / min. The mixture was calcined at a constant temperature of 350°C for 4 hours. 0.2 g of the powdered substance obtained after the calcination was weighed and placed in a quartz boat, which was then placed in a vacuum tube furnace. The temperature was raised to the reduction temperature at a rate of 5°C / min under nitrogen protection, and the mixture was reduced with hydrogen at 350°C for 2 hours. After the reduction was completed, the temperature was lowered to room temperature under nitrogen protection to obtain a formed Ru / ZnLa catalyst.

[0091] Weigh 0.1 g of Ru / ZnLa catalyst and place it in a 50 mL liner of a micro autoclave, add 15 mL of isobutanol, 1.5 g of m-xylenediamine, put in a magnet, seal the autoclave, replace the air in the autoclave with nitrogen 4 times, evacuate the autoclave with a vacuum pump, and then press and hold the heating button to start heating. When the set reaction temperature of 110°C is reached, hydrogen is introduced and pressurized to 3.0 MPa, the stirring button is pressed and the reaction timing starts. After 3 hours of reaction, the reaction is terminated, the reaction mixture is filtered, and the content of each substance in the filtrate is analyzed by gas chromatography. The conversion rate of m-xylenediamine is 90.9%, and the selectivity of 1,3-cyclohexanedimethylamine is 82.5%.

[0092] Implementation principle:

[0093] Ruthenium modified by Ce and Al promotes the dispersion of active metal centers, introduces alkaline center active sites, and reduces the formation of by-products, thereby showing excellent catalytic hydrogenation activity and selectivity for MXDA hydrogenation to 1,3-BAC.

[0094] The principles and implementation methods of the present invention are described herein using specific examples, and the description of the above embodiments is only used to help understand the method and core ideas of the present invention. The above are only preferred implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention, which should be within the protection scope of the present invention.

Claims

1. A method for preparing a hydrotalcite-supported ruthenium-based catalyst, characterized in that: The steps include: S1: mixing lanthanum nitrate hexahydrate and zinc nitrate hexahydrate in a mass ratio of 1:(1.5-15), adding the mixture into deionized water and dispersing the mixture evenly; S2: adding sodium hydroxide and sodium carbonate in a mass ratio of 1:(0.5-2) to the mixture obtained in step S1 and dispersing them evenly; S3: After the reaction is completed, centrifugation is performed to obtain a solid product, and the solid product is dried and ground to obtain a hydrotalcite carrier; S4: adding the hydrotalcite carrier into 20-100 ml of isobutanol, stirring and dispersing uniformly; S5: mixing anhydrous ruthenium chloride with a mass ratio of 1% to 20% of the hydrotalcite carrier, aluminum nitrate nonahydrate and cerium nitrate hexahydrate with a mass ratio of (1 to 20):22, and adding the mixture obtained in step S4 to disperse evenly; S6: Raise the temperature to 40-100°C, age for 1-10 hours, and then stir at a constant temperature until all the solvent evaporates; S7: grinding the product obtained in step S6 to obtain a powdered solid; S8: gradually heating the powdered solid to 200-500° C. in a nitrogen atmosphere, calcining for 2-8 hours, introducing hydrogen, adjusting the temperature to 200-600° C. and performing constant temperature reduction for 1-6 hours; S9: After the reduction is completed, the temperature is lowered to room temperature in a nitrogen atmosphere to obtain the hydrotalcite-supported modified ruthenium-based catalyst.

2. The preparation method according to claim 1, characterized in that: In step S1, the dispersion method is ultrasonic dispersion first and then stirring dispersion, and the stirring dispersion time is 10 to 60 minutes; The dispersion process in step S2 includes: first stirring and dispersing for 10 to 60 minutes, then moving into a fume hood, and refluxing and stirring in an oil bath; In step S4, the stirring method is magnetic stirring, and the stirring time is 10 to 30 minutes.

3. The preparation method according to claim 1, characterized in that: The addition process of sodium hydroxide and sodium carbonate in step S2 includes: Add sodium hydroxide and sodium carbonate in a mass ratio of 1:(0.5-2) into deionized water and disperse them evenly to form a mixed solution; The mixed solution is added dropwise to the mixture obtained in step S1.

4. The preparation method according to claim 1, characterized in that: The process of centrifugal separation in step S3 includes: transferring the mixture obtained in step S2 into a centrifuge tube, and centrifuging at a rotation speed of 3000 to 8000 rpm for 5 to 20 minutes.

5. The preparation method according to claim 1, characterized in that: Step S5 specifically includes the following sub-steps: S5.1: Add 1% to 20% of anhydrous ruthenium chloride by mass of the hydrotalcite carrier, aluminum nitrate nonahydrate and cerium nitrate hexahydrate in a mass ratio of (1 to 20):22 into deionized water, and stir magnetically for 10 to 30 minutes; S5.2: under stirring, the mixed solution obtained in step S5.1 is added dropwise to the mixture obtained in step S4, and magnetic stirring is performed for 10 to 30 minutes after the addition.

6. The preparation method according to claim 2, characterized in that: The reflux stirring time is 2 to 20 hours.

7. The preparation method according to claim 1, characterized in that: In step S3, the drying temperature is 80-150° C. and the drying time is 5-20 hours.

8. The preparation method according to claim 1, characterized in that: The step S8 of gradually heating the powdered solid to 200-500° C. in a nitrogen atmosphere specifically includes: placing the powdered solid in a quartz boat, placing the boat in a vacuum tube furnace, introducing high-purity nitrogen with a purity of >99.999% at a flow rate of 35-90 mL / min, and heating the mixture to 200-500° C. at a heating rate of 4-10° C. / min using a programmed temperature increase.

9. An application of a hydrotalcite-supported modified ruthenium-based catalyst, characterized in that: The ruthenium-based catalyst modified by the hydrotalcite loading as claimed in any one of claims 1 to 8 is used to catalyze the hydrogenation reaction of m-xylylenediamine to prepare 1,3-cyclohexylenediamine, and the preparation process comprises: Adding the hydrotalcite-supported modified ruthenium-based catalyst, a polar solvent and m-xylylenediamine into an autoclave, wherein the mass of the hydrotalcite-supported modified ruthenium-based catalyst is 1% to 20% of the mass of the m-xylylenediamine; The reactor was sealed, and nitrogen was introduced to replace the air in the reactor 3 to 6 times; The reactor is evacuated, then heated to 60-200°C, hydrogen is introduced and pressurized to 1-10 MPa; After stirring for 1 to 10 hours, the mixed liquid in the reaction kettle is filtered to obtain the 1,3-cyclohexanedimethylamine.

10. The use according to claim 9, characterized in that: The polar solvent is at least one of tetrahydrofuran, 1,4-dioxane, isopropanol and dimethyl sulfoxide.