Preparation method and application of catalyst for synthesizing 1, 4-cyclohexanedimethanol

Abstract

The invention relates to the field of catalysts, and provides a preparation method and application of a catalyst for synthesizing 1, 4-cyclohexanedimethanol. The preparation method comprises the following steps: adding a carrier, a salt of noble metal, a salt of non-noble metal and potassium borohydride into a solvent, uniformly dispersing, evaporating the solvent, and collecting a solid; the molar ratio of the noble metal to the non-noble metal is 1: (0.5-2); the noble metal is one of ruthenium, palladium and platinum, and the non-noble metal is vanadium or rhenium; and roasting the solid at 300-500 DEG C for 2-4 hours, and reducing at 200-400 DEG C for 2-4 hours to obtain the catalyst. The invention also provides an application of the catalyst in synthesis of 1, 4-cyclohexanedimethanol. According to the invention, proper noble metal and non-noble metal are selected to be loaded on the carrier to prepare the catalyst, the catalytic performance is improved through the metal-metal oxide synergistic effect, and higher conversion rate of 1, 4-cyclohexanedicarboxylic acid and higher yield of 1, 4-cyclohexanedimethanol can be obtained at lower temperature and pressure.

Description

Technical Field

[0001] The present invention relates to the field of catalysts, and in particular to a preparation method and application of a catalyst for synthesizing 1,4-cyclohexanedimethanol. Background Art

[0002] There are one-step hydrogenation and two-step hydrogenation methods for preparing 1,4-cyclohexanedimethanol using terephthalic acid as raw material. In the one-step hydrogenation process, the catalyst and the product are difficult to separate and recover, so the relatively mature one in the prior art is the two-step hydrogenation method, that is, first hydrogenating the benzene ring in terephthalic acid to produce 1,4-cyclohexanedicarboxylic acid (CHDA), and then hydrogenating the carboxyl group on 1,4-cyclohexanedicarboxylic acid to obtain the target product 1,4-cyclohexanedimethanol. In the second step of hydrogenation, due to the large steric hindrance and weak polarity of the C=O double bond in the carboxyl group, it is very difficult to reduce the carboxyl group to alcohol, which is also a key factor restricting the preparation of 1,4-cyclohexanedimethanol using PTA as raw material.

[0003] In the prior art, catalysts containing two or more noble metals are used to improve the conversion rate of 1,4-cyclohexanedicarboxylic acid and the yield of the target product 1,4-cyclohexanedimethanol in the above process. For example, U.S. Pat. No. 6294703 uses a Ru-Sn-Pt / C catalyst containing two noble metals (Ru and Pt), which is expensive. The Ru-Sn-Pt / C catalyst in U.S. Pat. No. 6294703 needs to be heated at 230°C and H 2 Only when the reaction pressure is 10 MPa can the yield of 1,4-cyclohexanedimethanol be 91.8%, which places high demands on the reaction conditions. Therefore, an ideal solution is needed. Summary of the invention

[0004] The invention provides a preparation method and application of a catalyst for synthesizing 1,4-cyclohexanedimethanol. Suitable noble metals and non-noble metals are selected to be loaded on a carrier to prepare the catalyst, and the catalytic performance is improved through the synergistic effect of metal-metal oxides. A higher 1,4-cyclohexanedicarboxylic acid conversion rate (99.5%) and a 1,4-cyclohexanedimethanol yield (98.4%) can be obtained at a relatively low temperature (210° C.) and pressure (7 MPa).

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The method for preparing a catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) adding a carrier, a salt of a noble metal, a salt of a non-noble metal and potassium borohydride to a solvent, dispersing them uniformly, evaporating the solvent and collecting a solid; the molar ratio of the noble metal to the non-noble metal is 1:(0.5-2); the noble metal is one of ruthenium, palladium and platinum, and the non-noble metal is vanadium or rhenium; (2) The solid obtained in step (1) is calcined at 300-500° C. and reduced at 200-400° C. to obtain a catalyst.

[0006] Preferably, the carrier is activated carbon with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh.

[0007] Preferably, the activated carbon is coconut shell activated carbon.

[0008] Preferably, the carrier is pretreated: the carrier is dispersed in a 30-50wt% nitric acid solution, immersed at 80°C for 3 hours, filtered and refluxed with a 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, washed with deionized water until neutral, and then dried under reduced pressure at 2-8mmHg overnight for standby use.

[0009] Preferably, the salt is one or more of carbonate, nitrate, chloride and acetate.

[0010] Preferably, the noble metal is ruthenium and the non-noble metal is vanadium. 2 O 3 The metal-metal oxide interface effect formed between them is the strongest, which is beneficial to improving the catalytic activity.

[0011] Preferably, the total loading of precious metals and non-precious metals is 0.5-10wt%, more preferably 4-8wt%. If the loading is too high, the metal particles will agglomerate and stack, resulting in a decrease in the utilization rate of effective active components; if the loading is too low, the content of effective active components is low and the activity is poor.

[0012] Preferably, the mass of potassium borohydride is 0.8-3.5 times the sum of the mass of the salt of the noble metal and the mass of the salt of the non-noble metal.

[0013] Preferably, the dispersion is carried out by ultrasonic treatment at 40-60°C for 30-60 minutes. Ultrasonic treatment can increase the specific surface area of ​​the catalyst, better disperse the active components, and reduce the occurrence of agglomeration. The ultrasonic frequency is 15-25kHz and the power is 10-15W.

[0014] Preferably, the solvent is ultrapure water, which is heated to 90° C. and stirred continuously to evaporate the solvent.

[0015] Preferably, the solid is dried at 50-70°C overnight and then calcined.

[0016] Preferably, the reducing atmosphere is 5 vol% H 2 / N 2 (i.e. 5 vol% H 2 +95vol%N 2 ).

[0017] Preferably, the calcination time is 2-4 hours, and the reduction calcination time is 2-4 hours.

[0018] The present invention also provides application of the catalyst to synthesize 1,4-cyclohexanedimethanol, wherein 1,4-cyclohexanedicarboxylic acid is used as a raw material, and 1,4-cyclohexanedimethanol is prepared by hydrogen reduction under the catalysis of the catalyst.

[0019] Preferably, the mass ratio of the catalyst to 1,4-cyclohexanedicarboxylic acid is 1:5-30.

[0020] Preferably, water is used as solvent, the catalyst and 1,4-cyclohexanedicarboxylic acid are mixed, the reactor is sealed, and H 2 , react at 210-250°C and 5-10MPa for 3-8 hours, and obtain a post-reaction solution after separating the catalyst.

[0021] Preferably, the mass ratio of water to 1,4-cyclohexanedicarboxylic acid is 5-15:1.

[0022] Preferably, the reaction temperature is 210-220° C., the pressure is 5-7 MPa, and the reaction time is 3-5 hours.

[0023] Therefore, the beneficial effects of the present invention are: a heterogeneous catalyst with high activity for 1,4-cyclohexanedicarboxylic acid and high selectivity for 1,4-cyclohexanedimethanol is developed. According to the method of the present invention, the effective and efficient conversion of 1,4-cyclohexanedicarboxylic acid can be achieved under relatively low reaction temperature (210°C) and reaction pressure (7MPa); in addition, the catalyst preparation process is simple and easy to separate and recover. It can be seen that the technology provided by the present invention has both green and efficient practical application value and is very suitable for application in industrial production. Using the catalyst of the present invention, the conversion rate of 1,4-cyclohexanedicarboxylic acid can reach up to 99.5%, and the yield of 1,4-cyclohexanedimethanol is 98.4%, achieving a good technical implementation effect. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below through specific embodiments.

[0025] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the embodiments, unless otherwise specified, are all conventional methods in the art. Unless otherwise specified, parts are all weight parts, temperatures are expressed in ° C or at ambient temperature, and pressures are atmospheric pressure or near atmospheric pressure. There are many variations and combinations of reaction conditions (such as component concentrations, desired solvents, solvent mixtures, temperatures, pressures, and other reaction ranges) and conditions that can be used to optimize the purity and yield of the product obtained by the method, and only reasonable routine experiments will be required to optimize such method conditions.

[0026] Example 1. Preparation of Catalyst for Synthesizing 1,4-Cyclohexanedimethanol The following steps are involved: (1) Adding the carrier activated carbon, the salt of the precious metal, the salt of the non-precious metal and potassium borohydride into the ultrapure water solvent, dispersing them uniformly by ultrasonication at 40-60° C. for 30-60 min, heating them to 90° C. and stirring them continuously to evaporate the solvent, and collecting the solid.

[0027] The specific surface area of ​​the carrier activated carbon is 800-1200m 2 / g, with a particle size of 10-24 mesh, and coconut shell activated carbon is further preferred. The carrier activated carbon can be pretreated: the activated carbon is dispersed in a 30-50wt% nitric acid solution, soaked at 80°C for 3 hours, filtered and refluxed with a 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, washed with deionized water to neutrality, and then dried under reduced pressure at 2-8mmHg overnight for standby use.

[0028] The noble metal is one of ruthenium, palladium and platinum, and the non-noble metal is vanadium or rhenium; as a further preference, the noble metal is ruthenium and the non-noble metal is vanadium. Ru and V 2 O 3 The metal-metal oxide interface effect formed between them is the strongest, which is beneficial to improving the catalytic activity. The salt is one or more of carbonate, nitrate, chloride and acetate.

[0029] The molar ratio of noble metal to non-noble metal is preferably 1:(0.5-2). The addition of a small amount of non-noble metal oxide does not significantly improve the dispersion of noble metal particles, while excessive addition of non-noble metal will be enriched on the surface of Ru, blocking the Ru active sites exposed on the surface, thereby reducing the catalytic activity.

[0030] The total loading of precious metals and non-precious metals is 0.5-10wt%, preferably 4-8wt%. If the loading is too high, the metal particles will agglomerate and stack, resulting in a decrease in the utilization rate of effective active components; if the loading is too low, the content of effective active components is low and the activity is poor.

[0031] The mass of potassium borohydride is 0.8-3.5 times the sum of the masses of the salt of the precious metal and the salt of the non-precious metal.

[0032] Ultrasonic treatment can increase the specific surface area of ​​the catalyst, better disperse the active components, and reduce the occurrence of agglomeration. The ultrasonic frequency is 15-25kHz and the power is 10-15W.

[0033] (2) The solid obtained in step (1) was dried at 50-70°C overnight, calcined at 300-500°C for 2-4 hours, and then reduced at 200-400°C for 2-4 hours in a reducing atmosphere of 5 vol% H 2 / N 2 (i.e. 5 vol% H 2 +95vol%N 2 ), to obtain a catalyst.

[0034] 2. Application of the catalyst in synthesizing 1,4-cyclohexanedimethanol The catalyst and 1,4-cyclohexanedicarboxylic acid are mixed in a mass ratio of 1:5-30, water is used as a solvent, and the mass ratio of water to 1,4-cyclohexanedicarboxylic acid is 5-15:1, the reactor is sealed, hydrogen is filled, and the reaction is carried out at 210-250°C and 5-10MPa for 3-8 hours, and the catalyst is separated to obtain a post-reaction solution. Preferably, the reaction temperature is 210-220°C, the pressure is 5-7MPa, and the reaction time is 3-5 hours.

[0035] Example 1 The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) Coconut shell activated carbon is used as the carrier with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh. Pre-treat the activated carbon: disperse the carrier in 30-50wt% nitric acid solution, soak at 80℃ for 3 hours, filter and reflux with 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, wash with deionized water to neutrality, and then dry under reduced pressure at 2-8mmHg overnight for standby use.

[0036] (2) Weigh 4.3 g of RuCl 3 ·3H 2 O, 2.4 g NH 4 VO 3 , 15.0g KBH 450.0 g of pretreated activated carbon was added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20 kHz and a power of 12.23 W. Then it was transferred to a flask and heated and stirred until the solvent evaporated, and the temperature was maintained at 90°C. The solid was collected and dried in an oven at 60°C overnight, and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min, and then heated at 400°C and 5% H 2 / N 2 The reduction was carried out under the conditions of 2 hours with a heating rate of 3°C / min, and the catalyst was obtained after the reduction.

[0037] After ICP analysis, the catalyst is 3wt%Ru-1.5wt%V-5wt%B / C catalyst, and the Ru / V molar ratio is 1 / 1. After XPS analysis, V is mainly V 2 O 3 exists in the form of.

[0038] Example 2 The difference from Example 1 is that NH 4 VO 3 The amount used was 4.8 g. The obtained catalyst was a 3wt% Ru-3wt% V-5wt% B / C catalyst, and the Ru / V molar ratio was 1 / 2.

[0039] The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) Coconut shell activated carbon is used as the carrier with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh. Pre-treat the activated carbon: disperse the carrier in 30-50wt% nitric acid solution, soak at 80℃ for 3 hours, filter and reflux with 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, wash with deionized water to neutrality, and then dry under reduced pressure at 2-8mmHg overnight for standby use.

[0040] (2) Weigh 4.3 g of RuCl 3 ·3H 2 O, 4.8 g NH 4 VO 3 , 15.0g KBH 4 50.0 g of pretreated activated carbon was added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20 kHz and a power of 12.23 W. Then it was transferred to a flask and heated and stirred until the solvent evaporated, and the temperature was maintained at 90°C. The solid was collected and dried in an oven at 60°C overnight, and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min, and then heated at 400°C and 5% H 2 / N 2The reduction was carried out under the conditions of 2 hours with a heating rate of 3°C / min, and the catalyst was obtained after the reduction.

[0041] After ICP analysis, the catalyst is 3wt%Ru-3wt%V-5wt%B / C catalyst, and the Ru / V molar ratio is 1 / 2. After XPS analysis, V is mainly V 2 O 3 exists in the form of.

[0042] Example 3 The difference from Example 1 is that NH 4 VO 3 The amount used was 1.2 g. The obtained catalyst was a 3wt% Ru-0.8wt% V-5wt% B / C catalyst, and the Ru / V molar ratio was 1 / 0.5.

[0043] The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) Coconut shell activated carbon is used as the carrier with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh. Pre-treat the activated carbon: disperse the carrier in 30-50wt% nitric acid solution, soak at 80℃ for 3 hours, filter and reflux with 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, wash with deionized water to neutrality, and then dry under reduced pressure at 2-8mmHg overnight for standby use.

[0044] (2) Weigh 4.3 g of RuCl 3 ·3H 2 O, 1.2 g NH 4 VO 3 , 15.0g KBH 4 50.0 g of pretreated activated carbon was added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20 kHz and a power of 12.23 W. Then it was transferred to a flask and heated and stirred until the solvent evaporated, and the temperature was maintained at 90°C. The solid was collected and dried in an oven at 60°C overnight, and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min, and then heated at 400°C and 5% H 2 / N 2 The reduction was carried out under the conditions of 2 hours with a heating rate of 3°C / min, and the catalyst was obtained after the reduction.

[0045] After ICP analysis, the catalyst is 3wt%Ru-0.8wt%V-5wt%B / C catalyst, and the Ru / V molar ratio is 1 / 0.5. After XPS analysis, V is mainly V 2 O 3 exists in the form of.

[0046] Example 4 The difference from Example 1 is that the amount of activated carbon used after pretreatment is 100 g. The obtained catalyst is 1.5 wt% Ru-0.8 wt% V-3 wt% B / C, and the Ru / V molar ratio is 1 / 1.

[0047] The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) Coconut shell activated carbon is used as the carrier with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh. Pre-treat the activated carbon: disperse the carrier in 30-50wt% nitric acid solution, soak at 80℃ for 3 hours, filter and reflux with 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, wash with deionized water to neutrality, and then dry under reduced pressure at 2-8mmHg overnight for standby use.

[0048] (2) Weigh 4.3 g of RuCl 3 ·3H 2 O, 2.4 g NH 4 VO 3 , 15.0g KBH 4 100.0 g of pretreated activated carbon was added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20 kHz and a power of 12.23 W. Then it was transferred to a flask and heated and stirred until the solvent evaporated, and the temperature was maintained at 90°C. The solid was collected and dried in an oven at 60°C overnight, and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min, and then heated at 400°C and 5% H 2 / N 2 The reduction was carried out under the conditions of 2 hours with a heating rate of 3°C / min, and the catalyst was obtained after the reduction.

[0049] After ICP analysis, the catalyst is 1.5wt%Ru-0.8wt%V-3wt%B / C catalyst, and the Ru / V molar ratio is 1 / 1. After XPS analysis, V is mainly V 2 O 3 exists in the form of.

[0050] Example 5 The difference from Example 1 is that the amount of activated carbon used after pretreatment is 25 g. The obtained catalyst is 6 wt% Ru-3 wt% V-10 wt% B / C, and the Ru / V molar ratio is 1 / 1.

[0051] The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) Coconut shell activated carbon is used as the carrier with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh. Pre-treat the activated carbon: disperse the carrier in 30-50wt% nitric acid solution, soak at 80℃ for 3 hours, filter and reflux with 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, wash with deionized water to neutrality, and then dry under reduced pressure at 2-8mmHg overnight for standby use.

[0052] (2) Weigh 4.3 g of RuCl 3 ·3H 2 O, 2.4 g NH 4 VO 3 , 15.0g KBH 4 25.0 g of pretreated activated carbon was added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20 kHz and a power of 12.23 W. Then it was transferred to a flask and heated and stirred until the solvent evaporated, and the temperature was maintained at 90°C. The solid was collected and dried in an oven at 60°C overnight, and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min, and then heated at 400°C and 5% H 2 / N 2 The reduction was carried out under the conditions of 2 hours with a heating rate of 3°C / min, and the catalyst was obtained after the reduction.

[0053] After ICP analysis, the catalyst is 6wt%Ru-3wt%V-10wt%B / C catalyst, and the Ru / V molar ratio is 1 / 1. After XPS analysis, V is mainly V 2 O 3 exists in the form of.

[0054] Example 6 The difference from Example 1 is that NH 4 VO 3 Replaced by NH 4 R 4 The obtained catalyst is 3wt%Ru-5.5wt%Re-5wt%B / C, and the Ru / Re molar ratio is 1 / 1. XPS analysis shows that Re mainly exists in the valence state of +6.

[0055] The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) Coconut shell activated carbon is used as the carrier with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh. Pre-treat the activated carbon: disperse the carrier in 30-50wt% nitric acid solution, soak at 80℃ for 3 hours, filter and reflux with 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, wash with deionized water to neutrality, and then dry under reduced pressure at 2-8mmHg overnight for standby use.

[0056] (2) Weigh 4.3 g of RuCl 3 ·3H 2 O, 5.4 g NH 4 R 4 , 15.0g KBH 4 50.0 g of pretreated activated carbon was added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20 kHz and a power of 12.23 W. Then it was transferred to a flask and heated and stirred until the solvent evaporated, and the temperature was maintained at 90°C. The solid was collected and dried in an oven at 60°C overnight, and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min, and then heated at 400°C and 5% H 2 / N 2 The reduction was carried out under the conditions of 2 hours with a heating rate of 3°C / min, and the catalyst was obtained after the reduction.

[0057] After ICP analysis, the catalyst is 3wt%Ru-5.5wt%Re-5wt%B / C catalyst, and the Ru / Re molar ratio is 1 / 1. After XPS analysis, Re mainly exists in the valence state of +6.

[0058] Example 7 The difference from Example 1 is that RuCl 3 ·3H 2 O replaced by K 2 PtCl 6 The obtained catalyst was 3wt% Pt-1.5wt% V-5wt% B / C.

[0059] The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) Coconut shell activated carbon is used as the carrier with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh. Pre-treat the activated carbon: disperse the carrier in 30-50wt% nitric acid solution, soak at 80℃ for 3 hours, filter and reflux with 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, wash with deionized water to neutrality, and then dry under reduced pressure at 2-8mmHg overnight for standby use.

[0060] (2) Weigh 4.2 g K 2 PtCl 6 、2.4g NH 4 VO 3 , 15.0g KBH 450.0 g of pretreated activated carbon was added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20 kHz and a power of 12.23 W. Then it was transferred to a flask and heated and stirred until the solvent evaporated, and the temperature was maintained at 90°C. The solid was collected and dried in an oven at 60°C overnight, and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min, and then heated at 400°C and 5% H 2 / N 2 The reduction was carried out under the conditions of 2 hours with a heating rate of 3°C / min, and the catalyst was obtained after the reduction.

[0061] After ICP analysis, the catalyst was 3wt% Pt-1.5wt% V-5wt% B / C catalyst.

[0062] Example 8 The difference from Example 1 is that RuCl 3 ·3H 2 O replaced by Na 2 PdCl 4 The obtained catalyst was 3wt% Pd-1.5wt% V-5wt% B / C.

[0063] The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: (1) Coconut shell activated carbon is used as the carrier with a specific surface area of ​​800-1200m 2 / g, particle size is 10-24 mesh. Pre-treat the activated carbon: disperse the carrier in 30-50wt% nitric acid solution, soak at 80℃ for 3 hours, filter and reflux with 5-20wt% sodium hydroxide solution at the same temperature for 3 hours, wash with deionized water to neutrality, and then dry under reduced pressure at 2-8mmHg overnight for standby use.

[0064] (2) Weigh 4.8 g Na 2 PdCl 4 、2.4g NH 4 VO 3 , 15.0g KBH 4 50.0 g of pretreated activated carbon was added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20 kHz and a power of 12.23 W. Then it was transferred to a flask and heated and stirred until the solvent evaporated, and the temperature was maintained at 90°C. The solid was collected and dried in an oven at 60°C overnight, and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min, and then heated at 400°C and 5% H 2 / N 2 The reduction was carried out under the conditions of 2 hours with a heating rate of 3°C / min, and the catalyst was obtained after the reduction.

[0065] After ICP analysis, the catalyst was 3wt% Pd-1.5wt% V-5wt% B / C catalyst.

[0066] Comparative Example Comparative Example 1 The difference from Example 1 is that the catalyst is only loaded with Ru. The obtained catalyst is 3wt% Ru / C. Specifically: The preparation method of the catalyst for synthesizing 1,4-cyclohexanedimethanol comprises the following steps: Weigh 3.9 g RuCl 3 ·3H 2 O and 50.0g of pretreated activated carbon were added to an appropriate amount of ultrapure water and ultrasonicated at 50°C for 30 minutes with an ultrasonic frequency of 20kHz and a power of 12.23W. Then the mixture was transferred to a flask and heated and stirred until the solvent evaporated, with the temperature maintained at 90°C. The collected solid was dried in an oven at 60°C overnight and then calcined in a muffle furnace at 500°C for 2 hours with a heating rate of 3°C / min and heated at 400°C and 5% H 2 / N 2 The catalyst was reduced under the conditions of 50°C / min for 2 hours with a heating rate of 3°C / min to obtain catalyst I. After ICP analysis, catalyst I was recorded as a 3wt% Ru / C catalyst.

[0067] Comparative Example 2 The difference from Example 1 is that the catalyst has no non-noble metal loading. The obtained catalyst is 3wt%Ru-5wt%B / C.

[0068] Comparative Example 3 The difference from Example 1 is that 2.4 g NH 4 VO 3 Replaced with 4.0 g NH 4 MoO 4 The obtained catalyst is 3wt%Ru-2.8wt%Mo-5wt%B / C, and the Ru / Mo molar ratio is 1 / 1. After XPS analysis, Mo is mainly in the form of MoO 2 exists in the form of.

[0069] Comparative Example 4 The difference from Example 1 is that 2.4 g NH 4 VO 3 Replaced with 5.2 g SnCl 4 The obtained catalyst is 3wt%Ru-3.5wt%Sn-5wt%B / C, and the Ru / Sn molar ratio is 1 / 1. After XPS analysis, Sn mainly exists in the state of metal element.

[0070] Comparative Example 5 The difference from Example 1 is that 4.3 g RuCl 3 ·3H 2 O is replaced by 4.3 g RhCl 3 ·3H 2 O. The obtained catalyst was 3wt%Rh-1.5wt%V-5wt%B / C.

[0071] Comparative Example 6 The difference from Example 1 is that the Ru / V molar ratio is lower than the preferred range. 4 VO 3 The amount used was 0.6 g. The obtained catalyst was a 3wt% Ru-0.4wt% V-5wt% B / C catalyst, and the Ru / V molar ratio was 1 / 0.25.

[0072] Comparative Example 7 The difference from Example 1 is that the Ru / V molar ratio is higher than the preferred range. 4 VO 3 The amount used was 6 g. The obtained catalyst was a 3wt% Ru-3.7wt% V-5wt% B / C catalyst, and the Ru / V molar ratio was 1 / 2.5.

[0073] Comparative Example 1 According to patent CN114308035, 2.0%Ru-7.6%Re-1.2%B-1.9%Mn / C catalyst was prepared. The process is as follows: 0.158g C 15 H 21 O 6 Ru, 0.221 g NH 4 R 4 , 0.138 g H 3 BO 3 and 0.124 g Mn(NO 3 ) 2 Dissolve in 2.5 mL of water, then add 1.8 g of activated carbon, stir evenly at room temperature, age for 12 hours, filter, wash, and dry overnight. The resulting solid powder is transferred to a tube furnace for reduction treatment under the conditions of H 2 The reduction was carried out at 450°C for 4 hours in a mixed atmosphere of 1:2 Ru / Ar. The obtained catalyst was 2.0%Ru-7.6%Re-1.2%B-1.9%Mn / C catalyst according to ICP analysis.

[0074] Comparative Example 2 According to patent US6294703, a 6.0% Ru-2.0% Pt-5% Sn / C catalyst was prepared as follows: 1.578 g RhCl 3 ·3H 2O, 0.516 g H 2 PtCl 6 , 0.95g SnCl 2 ·2H 2 O was dissolved in 3.6 mL of 5N HCl aqueous solution, followed by the addition of 8.55 g of pretreated activated carbon. The mixed solution was evaporated at 60 °C and 25 mmHg, then dried at 150 °C in Ar gas flow for 2 h, and finally dried at 450 °C and H 2 The catalyst was reduced in a gas stream for 2 hours to obtain a 6.0%Ru-2.0%Pt-5%Sn / C catalyst.

[0075] Performance Testing 1. Catalytic performance The catalysts of each embodiment and comparative example are used for catalytic reaction. Specifically: 100g of 1,4-cyclohexanedicarboxylic acid and 1000mL ultrapure water are added to an autoclave, followed by adding 5g of catalyst, stirring is started, hydrogen is then introduced into the autoclave and vented three times to exhaust the air in the autoclave, and after completion, the temperature is raised to 210°C, and then hydrogen is introduced until the pressure reaches 7MPa, and the reaction is started, during which the required hydrogen pressure is maintained until the reaction is completed, and the reaction time is 3 hours. After the reaction is completed, heating is stopped, and after the autoclave is cooled to room temperature, the catalyst in the autoclave is recovered, and the post-reaction solution is then analyzed by liquid chromatography, and the conversion rate of 1,4-cyclohexanedicarboxylic acid and the selectivity of 1,4-cyclohexanedimethanol are calculated according to the external standard method. The catalytic performance of each catalyst for hydrogenation of 1,4-cyclohexanedicarboxylic acid catalyst to prepare 1,4-cyclohexanedimethanol is shown in Table 1 below.

[0076] Table 1. Comparison of catalytic performance of catalysts catalyst CHDA conversion % CHDM selectivity % CHDM yield % Example 1 3wt%Ru-1.5wt%V-5wt%B / C 99.5 98.9 98.4 Example 2 3wt%Ru-3wt%V-5wt%B / C 79.8 98.7 78.8 Example 3 3wt%Ru-0.8wt%V-5wt%B / C 68.9 98.0 67.5 Example 4 1.5wt%Ru-0.8wt%V-3wt%B / C 40.9 98.9 40.5 Example 5 6wt%Ru-3wt%V-10wt%B / C 99.9 98.3 98.2 Example 6 3wt%Ru-5.5wt%Re-5wt%B / C 51.0 78.5 39.8 Example 7 3wt%Pt-1.5wt%V-5wt%B / C 60.8 75.1 45.7 Example 8 3wt%Pd-1.5wt%V-5wt%B / C 72.8 88.1 64.1 Comparative Example 1 3wt%Ru / C 20.5 40.8 8.4 Comparative Example 2 3wt%Ru-5wt%B / C 26.1 45.0 11.8 Comparative Example 3 3wt%Ru-2.8wt%Mo-5wt%B / C 38.5 60.7 23.4 Comparative Example 4 3wt%Ru-3.5wt%Sn-5wt%B / C 44.3 28.9 12.8 Comparative Example 5 3wt%Rh-1.5wt%V-5wt%B / C 58.9 45.2 26.6 Comparative Example 6 3wt%Ru-0.4wt%V-5wt%B / C 51.5 95.3 49.1 Comparative Example 7 3wt%Ru-3.7wt%V-5wt%B / C 60.8 98.2 59.7 Comparative Example 1 2.0%Ru-7.6%Re-1.2%B-1.9%Mn / C 82.8 91.1 75.4 Comparative Example 2 6.0%Ru-2.0%Pt-5%Sn / C 88.9 95.2 84.6 It can be seen from the above table that the catalysts prepared in various embodiments of the present invention have excellent catalytic performance.

[0077] Compared with Example 1, the non-noble metal oxide in Comparative Example 3 is V 2 O 3 Replaced by MoO 2 , the CHDA conversion rate decreases because MoO 2 The addition of will induce the Ru particle size to increase. 2 O 3 When Sn is replaced, the CHDM selectivity decreases significantly, which is because the adsorption capacity between Sn and carboxylic acid groups is weaker than that between V and 2 O 3 In Comparative Example 5, the noble metal is replaced by Rh from Ru because Rh-V 2 O 3 The metal-metal oxide synergistic effect between them is lower than that between Ru-V2 O 3 , resulting in a decrease in the catalytic performance of the catalyst. The reason for the decrease in CHDA conversion in Comparative Examples 6 and 7 is that a small amount of non-precious metal oxide V 2 O 3 The addition of V did not significantly improve the dispersion of Ru particles, while the excessive addition of 2 O 3 The Ru is enriched on the surface of Ru, blocking the Ru active sites exposed on the surface, thereby reducing the catalytic activity.

[0078] 2. Catalyst Repeatability Performance Evaluation The catalyst involved in the reaction is recovered and dried overnight before the catalyst repetitive performance evaluation is performed. Specifically, the above catalyst is dried and weighed, compared with the amount of catalyst used for the first time, the catalyst loss rate is calculated, and the mass of 1,4-cyclohexanedicarboxylic acid and ultrapure water is reduced accordingly according to the ratio. After the above substances are added to the autoclave, stirring is started, and then hydrogen is introduced into the autoclave and vented three times to exhaust the air in the autoclave. After completion, the temperature is raised to 210°C, and then hydrogen is introduced until the pressure reaches 7MPa. The reaction is started, and the required hydrogen pressure is maintained until the reaction is completed. The reaction time is 3 hours. After the reaction is completed, the heating is stopped, and after the autoclave is cooled to room temperature, the catalyst in the autoclave is recovered, and then the solution after the reaction is analyzed by liquid chromatography, and the conversion rate of 1,4-cyclohexanedicarboxylic acid and the selectivity of 1,4-cyclohexanedimethanol are calculated according to the external standard method. According to the above method, the catalyst is repetitively evaluated for the third to seventh times. The repetitive performance of the catalyst described in Example 1 is shown in Table 2 below.

[0079] Table 2. Catalytic reproducibility of the catalyst of Example 1 Number of reactions CHDA conversion % CHDM selectivity % CHDM yield % first 99.5 98.9 98.4 Second time 99.4 99.0 98.4 The third time 99.2 99.0 98.2 Fourth 99.4 98.9 98.3 Fifth 99.5 99.0 98.5 Sixth 99.7 98.9 98.6 Seventh 99.6 99.0 98.6 The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a catalyst for synthesizing 1,4-cyclohexanedimethanol, characterized in that: The following steps are involved: (1) adding a carrier, a salt of a noble metal, a salt of a non-noble metal and potassium borohydride to a solvent, dispersing them uniformly, evaporating the solvent and collecting a solid; the molar ratio of the noble metal to the non-noble metal is 1:(0.5-2); the noble metal is one of ruthenium, palladium and platinum, and the non-noble metal is vanadium or rhenium; (2) The solid obtained in step (1) is calcined at 300-500°C, and then reduction calcined at 200-400°C to obtain a catalyst.

2. The method for preparing the catalyst for synthesizing 1,4-cyclohexanedimethanol according to claim 1, characterized in that: The carrier is activated carbon with a specific surface area of ​​800-1200 m 2 / g, particle size is 10-24 mesh.

3. The method for preparing the catalyst for synthesizing 1,4-cyclohexanedimethanol according to claim 1 or 2, characterized in that: The salt is one or more of carbonate, nitrate, chloride and acetate.

4. The method for preparing the catalyst for synthesizing 1,4-cyclohexanedimethanol according to claim 1, characterized in that: The total loading of precious metals and non-precious metals is 0.5-10wt%.

5. The method for preparing the catalyst for synthesizing 1,4-cyclohexanedimethanol according to claim 1 or 4, characterized in that: The mass of potassium borohydride is 0.8-3.5 times the sum of the masses of the salt of the precious metal and the salt of the non-precious metal.

6. The method for preparing the catalyst for synthesizing 1,4-cyclohexanedimethanol according to claim 1, characterized in that: Dispersion is carried out by ultrasonication at 40-60 °C for 30-60 min.

7. The method for preparing the catalyst for synthesizing 1,4-cyclohexanedimethanol according to claim 1 or 6, characterized in that: The calcination time is 2-4 hours, and the reduction calcination time is 2-4 hours.

8. Use of the catalyst prepared by any one of claims 1 to 7, characterized in that: 1,4-cyclohexanedimethanol is prepared by using 1,4-cyclohexanedicarboxylic acid as a raw material and reducing it with hydrogen under the catalysis of the catalyst.

9. The use according to claim 8, characterized in that: The mass ratio of the catalyst to 1,4-cyclohexanedicarboxylic acid is 1:5-30.

10. The use according to claim 8 or 9, characterized in that: Using water as solvent, the catalyst and 1,4-cyclohexanedicarboxylic acid are mixed, the reactor is sealed, H2 is introduced, and the reaction is carried out at 210-250°C and 5-10 MPa for 3-8 hours.