Preparation method and application of palladium / amphoteric chelate resin hydrogenation catalyst

Abstract

The present invention belongs to the technical field of precious metal-supported catalysts, and specifically relates to a preparation method and application of a palladium / amphoteric chelate resin hydrogenation catalyst. The preparation method comprises the following steps: heating and stirring a primary amine resin, a phosphorous acid aqueous solution, and hydrochloric acid, followed by adding formaldehyde and keeping the temperature low to obtain a functionalized resin; purifying the functionalized resin in an ion exchange column, and then washing with water to obtain an amphoteric chelate resin; adding a palladium nitrate solution to the amphoteric chelate resin, stirring, filtering, and washing to obtain an amphoteric chelate resin loaded with palladium ions, and then subjecting the resin to liquid-phase reduction with ascorbic acid and gas-phase reduction with a mixed hydrogen stream to obtain a palladium / amphoteric chelate resin hydrogenation catalyst. The application is to use the prepared hydrogenation catalyst for the hydrogenation of furfuryl alcohol to produce cyclopentanone. The present invention designs a novel preparation method to address the problems of insufficient selectivity, catalytic activity, and long-term structural stability of ion exchange resin-based catalysts obtained by current preparation methods.

Description

Technical Field

[0001] The invention belongs to the technical field of precious metal supported catalysts, and particularly relates to a preparation method and application of a palladium / amphoteric chelate resin hydrogenation catalyst. Background Art

[0002] Cyclopentanone is an organic compound with significant application value. From the perspective of chemical synthesis and industrial application, it has shown significant application value in a variety of fields, including cosmetics, medicine, energy, national defense, and materials. Given its importance, the optimization and innovation of its preparation process has become a focus of attention in both academia and industry. Currently, the main methods for preparing cyclopentanone are the adipic acid thermal decomposition method, in addition to the cyclopentene oxidation method, the cyclopentane method, and the catalytic oxidation method of cyclopentanol. However, the raw materials used in these traditional methods are mostly derived from fossil energy, which increases fossil energy consumption and is not in line with the current trend of low-VOC production in the chemical industry. Therefore, the development of a synthetic process based on renewable resources, environmentally friendly, and highly atom-economical is of great significance to the development of the cyclopentanone industry.

[0003] The catalytic hydrogenation of furfuryl alcohol has attracted considerable attention as a potential green synthetic route due to its wide availability of raw materials, low cost, and efficient utilization of biomass resources. This process, starting with furfuryl alcohol, achieves efficient conversion of cyclopentanone through catalytic hydrogenation, significantly improving energy efficiency and adhering to the fundamental principles of green chemistry. Therefore, research on the hydrogenation of furfuryl alcohol to cyclopentanone is not only of great scientific significance but also potentially offers a sustainable technological path for the industrial production of cyclopentanone.

[0004] The process of hydrogenating furfuryl alcohol to produce cyclopentanone primarily relies on copper, cobalt, nickel, palladium, or platinum-based catalysts, such as molecular sieve catalysts, supported metal catalysts, and ion exchange resin-based catalysts. Molecular sieve catalysts are susceptible to mass transfer limitations in non-polar or high-viscosity reaction media, resulting in reduced reaction efficiency. Some molecular sieve catalysts are irreversibly deactivated when exposed to aqueous environments for extended periods, limiting their application. Furthermore, supported metal catalysts are susceptible to metal detachment during the reaction, causing gradual deactivation. For example, supported metal catalysts described in patents CN118949983A, CN113649004A, CN117563600A, and CN114605246A, among others, suffer from uneven metal distribution and easy dissolution when prepared using traditional impregnation methods. This leads to significant batch variability and compromises the consistency of catalytic performance. In contrast, ion exchange resin-based catalysts have shown certain advantages in catalytic applications, which are mainly reflected in the following aspects: (1) Ion exchange resins show good stability in aqueous phase, organic phase and two-phase system, and are ideal carriers; (2) When ion exchange resins are used as carriers, metal active components are bound to ion exchange resins by ion exchange or chelation, which effectively reduces the risk of metal ion detachment; (3) Ion exchange resins have good physical, chemical and mechanical stability and can specifically tolerate acidic or alkaline environments, which is beneficial to extend the service life of the catalyst and reduce the operating costs in the industrial production process. Currently, there are many patents that disclose methods for preparing ion exchange resin-based catalysts using cation exchange resins and palladium nitrate, such as CN1457927A and CN1288782A. When preparing ion exchange resin-based catalysts, these patents all use acidic cation exchange resins and palladium ions for ion exchange, which has the problem of uneven metal loading, thereby affecting the stability and service life of the catalyst. To address the above problems, Chinese patent CN101486000A discloses a method in which a chelating agent is first used to form a chelate with a palladium salt, and then an impregnation method is used to bind the palladium chelate to an ion exchange resin via van der Waals forces. This is an indirect chelation method using a third component. Although it improves the uniformity of palladium ion loading to a certain extent, some chelating agents used in this method, such as dimethylglyoxime and diphenylthiocarbazone, have poor water solubility. The resulting palladium chelate has the risk of gradually aggregating in the resin pores, affecting catalytic activity and long-term stability. In view of the above problems, it is urgent to develop a method for preparing a novel resin catalyst to improve the selectivity, catalytic activity, and long-term structural stability of ion exchange resin-based catalysts, especially such catalysts that can be used to catalyze the hydrogenation of furfuryl alcohol to produce cyclopentanone. Summary of the Invention

[0005] The present invention aims to provide a method for preparing a palladium / amphoteric chelate resin hydrogenation catalyst to solve the problems of insufficient selectivity, catalytic activity and long-term structural stability of ion exchange resin-based catalysts obtained by current preparation methods. The present invention also provides an application, wherein the catalyst can be used for hydrogenating furfuryl alcohol to prepare cyclopentanone.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] The preparation method of the palladium / amphoteric chelate resin hydrogenation catalyst of the present invention comprises the following steps:

[0008] (1) A primary amine resin, a phosphorous acid aqueous solution, and hydrochloric acid are mixed, heated and stirred, and then formaldehyde is added and kept warm. The functionalized resin is obtained by cooling and filtering. The primary amine resin is made by introducing primary amino groups into polystyrene-divinylbenzene resin and is a commercially available product.

[0009] (2) The functionalized resin is loaded into an ion exchange column, and the resin is treated with pure water and hydrochloric acid in sequence, and then washed with water to obtain an amphoteric chelating resin;

[0010] (3) adding palladium nitrate solution to the amphoteric chelate resin, stirring and filtering, and then washing the amphoteric chelate resin until no palladium ions are left in the washed water, thereby obtaining an amphoteric chelate resin loaded with palladium ions;

[0011] (4) Using an ascorbic acid aqueous solution to carry out liquid phase reduction of the palladium ion-loaded amphoteric chelating resin, after standing, filtering, washing and drying, the palladium ion-loaded amphoteric chelating resin is then subjected to gas phase reduction using a mixed hydrogen flow to obtain a palladium / amphoteric chelating resin hydrogenation catalyst.

[0012] in:

[0013] In the step (1), the concentration of the phosphorous acid aqueous solution is 18-22 wt%, the concentration of the hydrochloric acid is 36-38 wt%, the mass ratio of the phosphorous acid aqueous solution, the hydrochloric acid and the primary amine resin is (1.25-1.45): (0.25-0.35): 1, the concentration of the formaldehyde is 33-42 wt%, and the mass ratio of the formaldehyde to the primary amine resin is (0.25-0.3): 1; the stirring temperature is 85-95 ° C, and the holding time is 10-15 h.

[0014] In the step (2), the purity of the hydrochloric acid is 4-7 wt %, the mass ratio of pure water, hydrochloric acid and functionalized resin is (7-12):4:1, and the flow rate of pure water and hydrochloric acid is 2-4 BV / h; during water washing, when the pH value of the effluent is ≥3.0, the water washing is completed.

[0015] In the step (2), the physical and chemical indicators of the amphoteric chelating resin are as follows: particle size range 0.4~0.5mm, uniformity coefficient 1.19~1.21, water content 54.22~55.35%, wet apparent density 0.73g / mL, wet true density 1.10~1.12g / mL, infiltration and grinding ball rate 99%, weak acid group exchange capacity 2.23~2.40mmol / g, weak base group exchange capacity 2.28~2.52mmol / g.

[0016] In the step (3), the concentration of the palladium nitrate solution is 0.75-0.85 wt %, the mass ratio of the palladium nitrate solution to the amphoteric chelating resin is (1.75-5.0):1; the stirring temperature is 23-30° C., and the stirring time is 4-6 h.

[0017] In the step (3), the palladium ion-loaded amphoteric chelating resin is cleaned by washing with pure water multiple times followed by filtration or by passing through an ion exchange column.

[0018] In the step (4), the concentration of the ascorbic acid aqueous solution is 9.5-10.5 wt %, the mass ratio of the ascorbic acid aqueous solution to the amphoteric chelating resin is (1-3):1, the standing time is 6-12 h, and the drying temperature is 60-70° C.

[0019] In the step (4), the volume ratio of hydrogen to nitrogen in the mixed hydrogen flow is 1:(7-9), the gas phase reduction temperature is 220-250°C, and the gas phase reduction time is 3-5h; the palladium content of the palladium / amphoteric chelate resin hydrogenation catalyst is 1.0-3.5wt%.

[0020] The application of the palladium / amphoteric chelate resin hydrogenation catalyst of the present invention comprises the following steps: adding furfuryl alcohol and water into a reaction kettle, continuously adding the palladium / amphoteric chelate resin hydrogenation catalyst, starting stirring, introducing hydrogen to carry out hydrogenation reaction, and filtering to obtain cyclopentanone.

[0021] in:

[0022] The ratio of the palladium / amphoteric chelate resin hydrogenation catalyst to furfuryl alcohol is (0.1-0.3):1, and the mass ratio of furfuryl alcohol to water is 1:(10-100).

[0023] The reactor needs to be purged with hydrogen 5 to 10 times, the hydrogen pressure of the hydrogenation reaction is 1 to 3 MPa, the hydrogenation reaction temperature is 140 to 180°C, the stirring speed is 160 to 180 rpm, and the hydrogenation reaction time is 5 to 10 hours.

[0024] The structural formula of the palladium / amphoteric chelate resin hydrogenation catalyst prepared by the present invention is as follows:

[0025] .

[0026] The beneficial effects of the present invention are as follows:

[0027] (1) The present invention modifies the existing primary amine resin of polystyrene-divinylbenzene skeleton. Based on the macroporous structure and capillary action of polystyrene-divinylbenzene resin, aminomethylphosphonic acid group (-NHCH2-PO3H2) is selectively introduced into the macroporous structure and an appropriate amount of primary amino group (-CH2NH2) is retained to prepare an amphoteric chelating resin. The two functional groups have a synergistic coordination effect: the protonated primary amino group (-NH3 + ) can quickly capture palladium ions. The simple structure of the primary amino group makes it easy to align on both sides of the pore, forming a planar quadrilateral coordination cavity together with the aminomethylphosphonic acid group. 2+ The electronic configuration is d 8 , the typical coordination configuration is a parallelogram, so this coordination cavity can minimize the Pd 2+ The repulsive force between d-orbital electrons improves the stability of the system.

[0028] (2) In the present invention, ascorbic acid is not only a reducing agent, but also has the function of not affecting the normal nucleation process of the hydrogenation catalyst and reducing the agglomeration of palladium nanoparticles: the reduction mechanism of ascorbic acid is a two-step single electron transfer process. Compared with conventional reducing agents such as NaBH4, the reduction rate of ascorbic acid is moderate, allowing Pd 0 Atoms nucleate uniformly within the pores of the amphoteric chelating resin. The weak coordination of ascorbic acid prevents it from interfering with the interaction between the amphoteric chelating resin and palladium ions during the reduction process. This allows the amphoteric chelating resin to fully utilize the confinement effects of the aminomethylphosphonic acid and primary amino groups within its macroporous structure, controlling the particle size of the hydrogenation catalyst, limiting the orientation and diffusion paths of the reactant molecules, and improving the selectivity of the target product. Furthermore, after the reaction, the protonated organic chains of the ascorbic acid can adsorb around the nascent palladium nanoparticles. Through their hydrophilic groups, they form a hydrogen bond network with other organic chains in the ascorbic acid and water molecules, reducing the movement of water molecules and creating steric hindrance, preventing particle aggregation and ensuring the catalytic activity of the hydrogenation catalyst.

[0029] Sodium borohydride and hydrazine hydrate are commonly used metal ion reducing agents. Strong reducing agents such as sodium borohydride or hydrazine hydrate can cause palladium ions to migrate and aggregate within the amphoteric chelate resin carrier, affecting the dispersion of the metal within the macroporous structure of the amphoteric chelate resin. Ascorbic acid has a weaker reducing power than sodium borohydride and hydrazine hydrate, resulting in a milder reduction reaction. Under the action of ascorbic acid, palladium ions chelated on the resin can be slowly reduced, facilitating the uniform dispersion of palladium within the amphoteric chelate resin. After liquid-phase reduction with ascorbic acid, zero-valent palladium is evenly dispersed on the amphoteric chelate resin. High-temperature hydrogen reduction is then used to ensure that all palladium ions are reduced to palladium metal.

[0030] (3) The preparation process of the catalyst is simple. After reduction treatment, it can catalyze the hydrogenation of furfuryl alcohol to cyclopentanone with high selectivity under low hydrogen pressure conditions. The yield of the present invention is significantly higher than that of the palladium-supported catalyst prepared by commercial chelate resin, and the catalyst has good stability in recycling. The palladium / amphoteric chelate resin hydrogenation catalyst of the present invention has abundant phosphonic acid groups attached to the resin skeleton, which can replace the hydrochloric acid in the traditional process to provide a complete acidic environment, avoiding the corrosion of the equipment by directly adding hydrochloric acid. In addition, the catalyst of the present invention is used in the aqueous phase, and no other reaction aids are required during the reaction process. No difficult-to-treat waste liquid is formed, which is environmentally friendly and conducive to large-scale industrial production. Experimental results show that the present invention uses a new hydrogenation catalyst to achieve efficient conversion of furfuryl alcohol to cyclopentanone, which not only increases the added value of biomass resources, but also complies with the basic principles of green chemistry. Furthermore, the present invention provides a new amphoteric chelate resin. The resin has stable physical and chemical properties, and its functional groups are easy to control. It can achieve stable loading of other metal ions as needed, expanding its application range. Therefore, the catalyst and application technology route provided by the present invention have important application value in the industrial production of cyclopentanone. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a gas chromatogram of the cyclopentanone-containing solution of Example 1;

[0032] Figure 2 is a gas chromatogram of the cyclopentanone-containing solution of Example 2;

[0033] Figure 3 This is a gas chromatogram of the cyclopentanone-containing solution of Example 3. DETAILED DESCRIPTION

[0034] The present invention is described and illustrated in detail below with reference to the embodiments.

[0035] Example 1

[0036] Preparation of palladium / amphoteric chelate resin hydrogenation catalyst:

[0037] (1) Accurately weigh 35g of primary amine resin and add it to a three-necked flask. Add 43.8g of 20wt% phosphorous acid aqueous solution and 10g of 38wt% hydrochloric acid. Heat to 90℃ under mechanical stirring. Then slowly add 8.8g of 37wt% formaldehyde. Keep warm for 15h, then cool naturally to room temperature. Filter out the functionalized resin. The primary amine resin is produced by Shandong Dechuan Chemical Technology Co., Ltd., brand D303.

[0038] (2) The functionalized resin was loaded into an ion exchange column and treated with pure water and 5 wt% hydrochloric acid in sequence in a top-in, bottom-out manner, with the mass ratio of pure water, dilute hydrochloric acid to functionalized resin being 8:4:1. The flow rate of pure water and dilute hydrochloric acid was 3 BV / h. The functionalized resin was then washed with pure water until the pH value of the effluent was ≥3.0 to obtain an amphoteric chelating resin.

[0039] The physical and chemical indicators of the amphoteric chelating resin are: particle size range 0.4~0.5mm, uniformity coefficient 1.21, water content 55.35%, wet apparent density 0.73g / mL, wet true density 1.11g / mL, infiltration and grinding ball rate 99%, weak acid group exchange capacity 2.35mmol / g, and weak base group exchange capacity 2.52mmol / g.

[0040] (3) Weigh 50 g of amphoteric chelating resin and add it to a 250 mL three-necked round-bottom flask, add 120 g of 0.8 wt% palladium nitrate solution, and mechanically stir at 25 °C for 4 h. Then filter out the solution and load the amphoteric chelating resin into an ion exchange column. Wash with pure water until there is no palladium ion in the effluent water, thereby obtaining an amphoteric chelating resin loaded with palladium ions.

[0041] (4) The palladium ion-loaded amphoteric chelate resin was added to a 250 mL beaker, and 50 g of a 10 wt % ascorbic acid aqueous solution was added. The mixture was allowed to stand at room temperature for 6 h, then filtered and washed three times with pure water. The mixture was then dried in a vacuum drying oven at 60 ° C, then loaded into a fixed bed, and the resin catalyst was subjected to gas phase reduction in a mixed hydrogen flow (hydrogen to nitrogen volume ratio of 1:9) at 220 ° C for 3 h. After cooling naturally, a palladium / amphoteric chelate resin hydrogenation catalyst was obtained. The palladium / amphoteric chelate resin hydrogenation catalyst was characterized by XRF, and the palladium loading was measured to be 1.8 wt %.

[0042] Catalytic hydrogenation of furfuryl alcohol to cyclopentanone:

[0043] 1.0 g of furfuryl alcohol and 19 mL of deionized water were weighed, mixed, and transferred to an autoclave. Subsequently, 0.2 g of palladium / amphoteric chelate resin hydrogenation catalyst was added.

[0044] The autoclave was replaced with hydrogen five times. After replacement, hydrogen was introduced to pressurize the autoclave to 1.4 MPa. The magnetic stirring device was activated at 180 rpm. The reaction system was heated to 160°C at a rate of 5°C / min for 5 h.

[0045] After the reaction is completed, the system is naturally cooled to room temperature, and the resin catalyst in the reaction solution is filtered to finally obtain a solution containing cyclopentanone. The conversion rate of furfuryl alcohol and the selectivity of cyclopentanone are detected by gas chromatography. Figure 1As shown, the furfuryl alcohol conversion rate was 98.280%, the cyclopentanone selectivity was 98.840%, and the cyclopentanone-containing solution was concentrated and crystallized to obtain cyclopentanone crystals with a calculated yield of 97.140%.

[0046] Example 2

[0047] Preparation of palladium / amphoteric chelate resin hydrogenation catalyst:

[0048] (1) Accurately weigh 35g of primary amine resin and add it to a three-necked flask, along with 50.8g of 18wt% phosphorous acid aqueous solution and 12.2g of 36wt% hydrochloric acid. Heat the mixture to 95°C under mechanical stirring, then slowly add 10g of 42wt% formaldehyde. Keep the mixture warm for 11h, then naturally cool to room temperature and filter out the functionalized resin. The primary amine resin is produced by Shandong Dechuan Chemical Technology Co., Ltd., brand D303.

[0049] (2) The functionalized resin was loaded into an ion exchange column and treated with pure water and 4 wt% hydrochloric acid in sequence in a top-in, bottom-out manner, with the mass ratio of pure water, dilute hydrochloric acid to functionalized resin being 12:4:1. The flow rate of pure water and dilute hydrochloric acid was 4 BV / h. The functionalized resin was then washed with pure water until the pH value of the effluent was ≥3.0 to obtain an amphoteric chelating resin.

[0050] The physical and chemical indicators of the resin are: particle size range 0.4~0.5mm, uniformity coefficient 1.19, water content 54.86%, wet apparent density 0.73g / mL, wet true density 1.12g / mL, infiltration and grinding ball rate 99%, weak acid group exchange capacity 2.23mmol / g, weak base group exchange capacity 2.38mmol / g.

[0051] (3) Weigh 20 g of amphoteric chelating resin and add it to a 500 mL three-necked round-bottom flask, add 100 g of 0.75 wt% palladium nitrate solution, and mechanically stir at 23 °C for 6 h. Then filter out the solution, load the amphoteric chelating resin-2 into an ion exchange column, and wash with pure water until there is no palladium ion in the effluent water, thereby obtaining an amphoteric chelating resin loaded with palladium ions.

[0052] (4) The palladium ion-loaded amphoteric chelate resin was added to a 250 mL beaker, and 60 g of a 9.5 wt% ascorbic acid aqueous solution was added. The mixture was allowed to stand at room temperature for 8 h, then filtered and washed three times with pure water. The mixture was then dried in a vacuum drying oven at 70 °C and loaded into a fixed bed. The resin catalyst was subjected to gas phase reduction in a mixed hydrogen flow (hydrogen to nitrogen volume ratio of 1:8) at 230 °C for 5 h. The mixture was cooled naturally to obtain a palladium / amphoteric chelate resin hydrogenation catalyst. The palladium / amphoteric chelate resin hydrogenation catalyst was characterized by XRF, and the palladium loading was measured to be 3.5 wt%.

[0053] Catalytic hydrogenation of furfuryl alcohol to cyclopentanone:

[0054] 1.0 g of furfuryl alcohol and 10 mL of deionized water were weighed, mixed, and transferred to an autoclave. Subsequently, 0.1 g of palladium / amphoteric chelate resin hydrogenation catalyst was added.

[0055] The autoclave was replaced with hydrogen 10 times. After replacement, hydrogen was introduced to pressurize the autoclave to 1.0 MPa. The magnetic stirring device was activated and set to 170 rpm. The reaction system was heated to 180°C at a rate of 5°C / min for 8 hours.

[0056] After the reaction is completed, the system is naturally cooled to room temperature, and the resin catalyst in the reaction solution is filtered to finally obtain a solution containing cyclopentanone. The conversion rate of furfuryl alcohol and the selectivity of cyclopentanone are detected by gas chromatography. Figure 2 As shown, the furfuryl alcohol conversion rate was 98.202%, the cyclopentanone selectivity was 98.923%, and the cyclopentanone-containing solution was concentrated and crystallized to obtain cyclopentanone crystals with a calculated yield of 97.144%.

[0057] Example 3

[0058] Preparation of palladium / amphoteric chelate resin hydrogenation catalyst:

[0059] (1) Accurately weigh 35g of primary amine resin and add it to a three-necked flask. Add 45g of 22wt% phosphorous acid aqueous solution and 8.8g of 37wt% hydrochloric acid. Heat to 85°C with mechanical stirring. Then slowly add 10.5g of 33wt% formaldehyde. Keep warm for 10h, then cool naturally to room temperature. Filter out the functionalized resin. The primary amine resin is produced by Shandong Dechuan Chemical Technology Co., Ltd., brand D303.

[0060] (2) The functionalized resin was loaded into an ion exchange column and treated with pure water and 7 wt% hydrochloric acid in sequence in a top-in, bottom-out manner, with the mass ratio of pure water, dilute hydrochloric acid to functionalized resin being 7:4:1. The flow rate of pure water and dilute hydrochloric acid was 2 BV / h. The functionalized resin was then washed with pure water until the pH value of the effluent was ≥3.0 to obtain an amphoteric chelating resin.

[0061] The physical and chemical indicators of the amphoteric chelating resin are: particle size range 0.4~0.5mm, uniformity coefficient 1.21, water content 54.22%, wet apparent density 0.73g / mL, wet true density 1.1g / mL, infiltration and grinding ball rate 99%, weak acid group exchange capacity 2.40mmol / g, and weak base group exchange capacity 2.28mmol / g.

[0062] (3) Weigh 40 g of amphoteric chelating resin and add it to a 500 mL three-necked round-bottom flask, add 70 g of 0.85 wt% palladium nitrate solution, and mechanically stir at 30 ° C for 5 h. Then filter out the solution, load the amphoteric chelating resin into an ion exchange column, and wash it with pure water until there is no palladium ion in the effluent water, thereby obtaining an amphoteric chelating resin loaded with palladium ions.

[0063] (4) The palladium ion-loaded amphoteric chelate resin was added to a 250 mL beaker, and 80 g of a 10.5 wt% ascorbic acid aqueous solution was added. The mixture was allowed to stand at room temperature for 12 h, then filtered and washed three times with pure water. The mixture was then dried in a vacuum drying oven at 65 °C and loaded into a fixed bed. The resin catalyst was subjected to gas phase reduction in a mixed hydrogen flow (hydrogen to nitrogen volume ratio of 1:7) at 250 °C for 3.5 h. After cooling naturally, a palladium / amphoteric chelate resin hydrogenation catalyst was obtained. The palladium / amphoteric chelate resin hydrogenation catalyst was characterized by XRF, and the palladium loading was measured to be 1.0 wt%.

[0064] Catalytic hydrogenation of furfuryl alcohol to cyclopentanone:

[0065] 1.0 g of furfuryl alcohol and 100 mL of deionized water were weighed, mixed, and transferred to an autoclave. Subsequently, 0.3 g of palladium / amphoteric chelate resin hydrogenation catalyst was added.

[0066] The autoclave was replaced with hydrogen eight times. After replacement, hydrogen was introduced to pressurize the autoclave to 3.0 MPa. The magnetic stirring device was activated at 160 rpm. The reaction system was heated to 140°C at a rate of 5°C / min for 10 h.

[0067] After the reaction is completed, the system is naturally cooled to room temperature, and the resin catalyst in the reaction solution is filtered to finally obtain a solution containing cyclopentanone. The conversion rate of furfuryl alcohol and the selectivity of cyclopentanone are detected by gas chromatography. Figure 3 It was found that the furfuryl alcohol conversion rate was 99.024%, the cyclopentanone selectivity was 99.012%, and the cyclopentanone-containing solution was concentrated and crystallized to obtain cyclopentanone crystals with a calculated yield of 98.046%.

[0068] Comparative Example 1

[0069] Preparation of comparative resin-based hydrogenation catalyst:

[0070] The functionalized resin in Example 1 was replaced by a commercially available chelating resin (produced by Shandong Dechuan Chemical Technology Co., Ltd., brand D467). The remaining steps and raw materials were the same as in Example 1 to prepare a comparative resin-based hydrogenation catalyst. The palladium content on the comparative resin-based hydrogenation catalyst was measured by XRF characterization technology to be 0.56 wt%.

[0071] Catalytic hydrogenation of furfuryl alcohol to cyclopentanone:

[0072] The steps were the same as in Example 1 to obtain a solution containing cyclopentanone. The conversion of furfuryl alcohol and the selectivity of cyclopentanone were detected by gas chromatograph. The detection of the solution containing cyclopentanone showed that the conversion of furfuryl alcohol was 91.236% and the selectivity of cyclopentanone was 65.041%.

[0073] Comparative Example 2

[0074] Preparation of comparative resin-based hydrogenation catalyst:

[0075] The functionalized resin in Example 1 was replaced by a primary ammonia resin (produced by Shandong Dechuan Chemical Technology Co., Ltd., brand D303). The remaining steps and raw materials were the same as in Example 1 to prepare a comparative resin-based hydrogenation catalyst. The palladium content of the comparative resin-based hydrogenation catalyst was measured by XRF characterization technology to be 0.21 wt%.

[0076] Catalytic hydrogenation of furfuryl alcohol to cyclopentanone:

[0077] The steps were the same as in Example 1 to obtain a solution containing cyclopentanone. The conversion of furfuryl alcohol and the selectivity of cyclopentanone were detected by gas chromatograph. The detection of the solution containing cyclopentanone showed that the conversion of furfuryl alcohol was 90.103% and the selectivity of cyclopentanone was 67.194%.

[0078] Comparative Example 3

[0079] Preparation of comparative resin-based hydrogenation catalyst:

[0080] The amphoteric chelating resin in Example 1 was replaced by a commercially available chelating resin (produced by Shandong Dechuan Chemical Technology Co., Ltd., brand D467). The remaining steps and raw materials were the same as in Example 1 to prepare a comparative resin-based hydrogenation catalyst. The palladium content on the comparative resin-based hydrogenation catalyst was measured by XRF characterization technology to be 0.37 wt%.

[0081] Catalytic hydrogenation of furfuryl alcohol to cyclopentanone:

[0082] The steps were the same as in Example 1 to obtain a solution containing cyclopentanone. The conversion of furfuryl alcohol and the selectivity of cyclopentanone were detected by gas chromatograph. The detection of the solution containing cyclopentanone showed that the conversion of furfuryl alcohol was 90.569% and the selectivity of cyclopentanone was 67.776%.

[0083] Comparative Example 4

[0084] When the phosphorous acid aqueous solution was replaced with aminodiacetic acid or aminotriacetic acid, the palladium loading was found to be less than 0.1%, and a qualified palladium / amphoteric chelate resin hydrogenation catalyst could not be produced, so no subsequent testing was performed.

[0085] Test Example 1

[0086] The palladium / amphoteric chelate resin hydrogenation catalyst prepared in Example 1 was used to catalyze the hydrogenation of furfuryl alcohol to prepare cyclopentanone. Different hydrogenation reaction times were set. The specific catalytic hydrogenation reaction steps were the same as in Example 1. The effect of reaction time on the furfuryl alcohol conversion rate and cyclopentanone selectivity was tested. The specific results are shown in Table 1.

[0087]

[0088] As can be seen from Table 1, the present invention limits the reaction time to 5-10 h. Within this time range, the yield of cyclopentanone can be guaranteed to be at a relatively high level. Too short or too long a time will lead to an increase in the yield of the by-product 2-cyclopentenone or cyclopentanol, resulting in a decrease in the yield of cyclopentanone.

[0089] Test Example 2

[0090] The palladium / amphoteric chelate resin hydrogenation catalyst prepared in Example 1 was used to catalyze the hydrogenation of furfuryl alcohol to prepare cyclopentanone. Different hydrogenation reaction pressures were set. The specific catalytic hydrogenation reaction steps were the same as in Example 1. The effect of the hydrogenation reaction pressure on the furfuryl alcohol conversion and cyclopentanone selectivity was tested. The specific results are shown in Table 2.

[0091]

[0092] As can be seen from Table 2, the present invention limits the reaction pressure to 1-3 MPa. Within this time range, the furfuryl alcohol conversion rate and the cyclopentanone yield can be guaranteed to be at a relatively high level. When the pressure is lower than this range, the effect of the present invention cannot be achieved.

[0093] Test Example 3

[0094] The palladium / amphoteric chelate resin hydrogenation catalyst prepared in Example 1 was used to catalyze the hydrogenation of furfuryl alcohol to prepare cyclopentanone. Different hydrogenation reaction temperatures were set. The specific catalytic hydrogenation reaction steps were the same as in Example 1. The effect of the hydrogenation reaction temperature on the furfuryl alcohol conversion and cyclopentanone selectivity was tested. The specific results are shown in Table 3.

[0095]

[0096] As shown in Table 3, the present invention limits the reaction temperature to 140-180° C. Within this temperature range, the selectivity of cyclopentanone can be guaranteed to be at a relatively high level. If the temperature is too high or too low, the optimal effect cannot be achieved.

[0097] Test Example 4

[0098] The reaction solutions in Examples 1 to 3 were filtered to obtain palladium / amphoteric chelate resin hydrogenation catalysts, which were then recycled. The same procedure was followed for Comparative Examples 1 to 3. The recycling results are shown in Table 4.

[0099]

[0100] " / " means that the yield after 5 applications was less than 40.000%, which is no longer valuable for industrial application and thus no further testing was performed. As shown in Table 4, the catalytic activity of the catalysts in Examples 1 to 3 did not decrease significantly after 20 applications.

Claims

1. A method for preparing a palladium / amphoteric chelate resin hydrogenation catalyst comprises the following steps: (1) A primary amine resin, a phosphorous acid aqueous solution, and hydrochloric acid are mixed, heated and stirred, and then formaldehyde is added and kept warm. The functionalized resin is obtained by cooling and filtering. The concentration of the phosphorous acid aqueous solution is 18-22 wt%, the concentration of the hydrochloric acid is 36-38 wt%, and the mass ratio of the phosphorous acid aqueous solution, the hydrochloric acid, and the primary amine resin is (1.25-1.45):(0.25-0.35):

1. (2) The functionalized resin was loaded into an ion exchange column, and the resin was treated with pure water and hydrochloric acid in sequence, and then washed with water to obtain an amphoteric chelating resin; the particle size range was 0.4-0.5 mm, the weak acid group exchange capacity was 2.23-2.40 mmol / g, and the weak base group exchange capacity was 2.28-2.52 mmol / g; (3) adding palladium nitrate solution to the amphoteric chelate resin, stirring and filtering, and then washing the amphoteric chelate resin until no palladium ions are left in the washed water, thereby obtaining an amphoteric chelate resin loaded with palladium ions; (4) Using an ascorbic acid aqueous solution to carry out liquid phase reduction of the palladium ion-loaded amphoteric chelating resin, after standing, filtering, washing and drying, the palladium ion-loaded amphoteric chelating resin is then subjected to gas phase reduction using a mixed hydrogen flow to obtain a palladium / amphoteric chelating resin hydrogenation catalyst.

2. the preparation method of palladium / amphoteric chelate resin hydrogenation catalyst according to claim 1, is characterized in that, In step (1), the concentration of formaldehyde is 33-42 wt %, the mass ratio of formaldehyde to primary amine resin is (0.25-0.3):1; the stirring temperature is 85-95° C., and the holding time is 10-15 h.

3. the preparation method of palladium / amphoteric chelate resin hydrogenation catalyst according to claim 1, is characterized in that, In step (2), the concentration of hydrochloric acid is 4-7 wt %, the mass ratio of pure water, hydrochloric acid and functionalized resin is (7-12):4:1, and the flow rate of pure water and hydrochloric acid is 2-4 BV / h; during water washing, when the pH value of the effluent is ≥3.0, the water washing is completed.

4. the preparation method of palladium / amphoteric chelate resin hydrogenation catalyst according to claim 1, is characterized in that, In step (2), the physical and chemical indicators of the amphoteric chelating resin are: uniformity coefficient 1.19~1.21, water content 54.22~55.35%, and wet true density 1.10~1.12 g / mL.

5. the preparation method of palladium / amphoteric chelate resin hydrogenation catalyst according to claim 1, is characterized in that, In step (3), the concentration of the palladium nitrate solution is 0.75-0.85 wt %, and the mass ratio of the palladium nitrate solution to the amphoteric chelating resin is (1.75-5.0):1; the stirring temperature is 23-30° C., and the stirring time is 4-6 h.

6. The preparation method of palladium / amphoteric chelate resin hydrogenation catalyst according to claim 1, wherein In step (4), the concentration of the ascorbic acid aqueous solution is 9.5-10.5 wt %, the mass ratio of the ascorbic acid aqueous solution to the amphoteric chelating resin is (1-3):1, the standing time is 6-12 h, and the drying temperature is 60-70° C.

7. The preparation method of palladium / amphoteric chelate resin hydrogenation catalyst according to claim 1, wherein In step (4), the volume ratio of hydrogen to nitrogen in the mixed hydrogen flow is 1:(7-9), the gas phase reduction temperature is 220-250°C, and the gas phase reduction time is 3-5h; the palladium content of the palladium / amphoteric chelate resin hydrogenation catalyst is 1.0-3.5wt%.

8. Use of a palladium / amphoteric chelate resin hydrogenation catalyst prepared by the preparation method of any one of claims 1 to 7, characterized in that: Furfuryl alcohol and water are added to a reactor, and a palladium / amphoteric chelate resin hydrogenation catalyst is added. Stirring is started, hydrogen is introduced for hydrogenation reaction, and cyclopentanone is obtained after filtration.

9. The use of a palladium / amphoteric chelate resin hydrogenation catalyst according to claim 8, wherein The ratio of palladium / amphoteric chelate resin hydrogenation catalyst to furfuryl alcohol is (0.1-0.3):1, and the mass ratio of furfuryl alcohol to water is 1:(10-100).

10. The use of the palladium / amphoteric chelate resin hydrogenation catalyst according to claim 8, characterized in that The reactor needs to be purged with hydrogen 5 to 10 times, the hydrogenation reaction pressure is 1 to 3 MPa, the hydrogenation reaction temperature is 140 to 180°C, the stirring speed is 160 to 180 rpm, and the hydrogenation reaction time is 5 to 10 hours.

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