Pd supported catalyst as well as preparation method and application thereof
By preparing highly dispersed nanoparticle-based Pd-supported catalysts, the problem of increased byproducts in the production of methyl isobutyl ketone and methyl isopentyl ketone was solved, achieving efficient co-production and separation, and meeting market demand.
Patent Information
- Application Number
- CN202511346922.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-19
- Publication Date
- 2026-01-27
AI Technical Summary
In the existing technology, the production process of methyl isobutyl ketone and methyl isopentyl ketone has the problem of increased by-products, resulting in low selectivity of target products, and the catalyst has insufficient activity and stability, making it difficult to meet market demand.
A Pd-supported catalyst preparation method was adopted, in which palladium nanoparticles were supported on a TiO2-SiO2 composite support and highly dispersed nanoparticle catalysts were prepared by equal-volume impregnation adsorption. This catalyst was used to catalyze the one-step co-production of methyl isobutyl ketone and methyl isopentyl ketone from a mixture of acetone and isobutyraldehyde.
It improves the conversion rate of isobutyraldehyde and the selectivity of methyl isopentyl ketone, reduces organic impurities, simplifies the separation process, and makes the reaction process stable and efficient, suitable for industrial production.
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Figure CN121402079A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of catalysts, in particular to a Pd supported catalyst and a preparation method and application thereof. BACKGROUND
[0002] Methyl isobutyl ketone (MIBK for short), also known as 4-methyl-2-pentanone, is an organic chemical product with excellent performance, which can be used as a high-grade organic solvent, and can also be used as an important organic synthesis raw material and chemical reaction intermediate, and can produce various downstream products such as special coating solvents, high-quality dewaxing solvents and high-performance rubber antioxidants, and is widely used in chemical industry, coating, medicine, dye, oil refining, rubber and other industries. The huge market demand prompts the efficient production of MIBK to become a research hotspot, and at present, MIBK is mainly produced by one-step method of acetone with simple process and low production cost.
[0003] Methyl isopentyl ketone (MIAK for short), also known as 2-octanone, can be used as a high-solid coating such as polyurethane paint resin, which can improve the laminar flow performance and film fullness, and can impart a gloss similar to the projection effect, and adding a certain amount can significantly improve the film performance. MIAK can also be used for the synthesis of acrylic resin, which can improve the compatibility between resins by using the solvent capacity of methyl isopentyl ketone. At the same time, methyl isopentyl ketone is also a raw material for synthesizing 7PPD antioxidant, which has excellent heat aging and ozone aging resistance, and has good protection effect on weathering and fatigue aging. With the increasingly stringent environmental protection requirements, the demand for high-solid coatings is increasing, and the demand for MIAK is also increasing. At present, domestic MIAK mainly depends on import, so it is urgent to independently develop a method for producing MIAK. The industrialized method for synthesizing methyl isopentyl ketone in the industry is mainly to use acetone and isobutyl aldehyde as raw materials to prepare by condensation and hydrogenation.
[0004] By comparing the production methods of methyl isobutyl ketone and methyl isopentyl ketone, it can be known that the basic principles are the same or even some raw materials are the same. Since the principle is aldol condensation and catalytic hydrogenation, it is possible to co-produce MIBK and MIAK. However, since both raw materials contain α-H atoms, self-condensation may occur during condensation, and cross condensation may also occur, which may cause multiple condensation reactions in the system, resulting in an increase in by-products and reducing the selectivity of the target product. Therefore, developing a multifunctional catalyst with high activity, high stability and high selectivity is the key to synthesizing MIAK and MIBK. SUMMARY
[0005] In order to overcome the deficiencies of the prior art, one of the purposes of the present application is to provide a preparation method of a Pd supported catalyst, which has the advantages of simple and green process, safe and easy-to-control reaction process, good crystallization of the prepared Pd supported catalyst, high-dispersed nanometer particle morphology, uniform size and uniform dispersion.
[0006] To solve the above problems, the technical scheme adopted by the present application is as follows: A preparation method of a Pd supported catalyst, comprising the following steps: S1, dissolving tetraethyl orthosilicate and tetrabutyl titanate in anhydrous ethanol, stirring and adjusting pH, aging at room temperature, and then drying to obtain a mixture; S2, extruding the mixture into a long strip, transferring it to a tube furnace for calcination, and preparing a TiO2-SiO2 composite carrier; S3, adding a measured amount of palladium chloride into propylene carbonate, filling hydrogen, and performing a reduction reaction under magnetic stirring to prepare a palladium nanoparticle solution; S4, adding a measured amount of TiO2-SiO2 composite carrier into the palladium nanoparticle solution of step S3 for equal-volume impregnation and adsorption, filtering, washing, and vacuum drying to obtain the Pd supported catalyst.
[0007] As a preferred embodiment of the present application, the pH in step S1 is adjusted to 8-11, and the aging time is 4-8h; the drying is water bath drying, and the drying time is 12-18h.
[0008] Further preferably, the pH in step S1 is adjusted to 9, and the aging time is 6h; the drying time is 15h.
[0009] As a preferred embodiment of the present application, the calcination temperature in step S2 is 300-400℃, and the calcination time is 3-5h.
[0010] Further preferably, the calcination temperature in step S2 is 350℃, and the calcination time is 4h.
[0011] As a preferred embodiment of the present application, the reduction pressure of the reduction reaction in step S3 is 1-5MPa, the reduction temperature is 50-110℃, and the reduction time is 1-6h.
[0012] Further preferably, the reduction pressure of the reduction reaction in step S3 is 3MPa, the reduction temperature is 80℃, and the reduction time is 4h.
[0013] The second purpose of the present application is to provide a Pd supported catalyst prepared by the preparation method as described above.
[0014] The third object of the present application is to provide the use of the Pd supported catalyst as described above in the production of methyl isobutyl ketone and methyl isoamyl ketone from mixed aldehyde ketone.
[0015] The fourth object of the present application is to provide a method for the production of methyl isobutyl ketone and methyl isoamyl ketone from mixed aldehyde ketone, which is the catalytic production of methyl isobutyl ketone and methyl isoamyl ketone from acetone and isobutyraldehyde by using the Pd supported catalyst as described above.
[0016] Specifically, the method for the production of methyl isobutyl ketone and methyl isoamyl ketone from mixed aldehyde ketone comprises the following steps: A. transferring the Pd supported catalyst to a fixed bed reaction device, and introducing protective gas N2 into the device to check the airtightness; B. continuously introducing hydrogen into the middle part of the device, and introducing mixed aldehyde ketone composed of acetone and isobutyraldehyde into the top part of the device, and controlling the reaction temperature to be 70-130℃ to promote the reaction to proceed rapidly; C. after the reaction is completed, the reaction liquid is filtered through the filter of the device, and the products methyl isobutyl ketone, methyl isoamyl ketone and unreacted mixed aldehyde ketone are separated by multi-stage condensation.
[0017] As a preferred embodiment of the present application, the mass ratio of acetone to isobutyraldehyde in the mixed aldehyde ketone of step B is 3.8-4.2:1; preferably 4:1.
[0018] As a preferred embodiment of the present application, the space velocity of hydrogen in step B is 10000-20000h -1 , preferably 15000h -1 ; the flow rate of the mixed aldehyde ketone is 50-80g . h -1 ; preferably 60g.h -1 .
[0019] Further preferably, the reaction temperature in step B is 100℃.
[0020] As a preferred embodiment of the present application, the multi-stage condensation in step C means that the condensation temperature is set according to the boiling points of acetone, isobutyraldehyde, methyl isobutyl ketone and methyl isoamyl ketone respectively to carry out multiple condensations.
[0021] As a preferred embodiment of the present application, after the separation in step C is completed, the unreacted mixed aldehyde ketone is re-proportioned and introduced into the reaction device for reaction; the unreacted gas phase components are condensed, and the gas is refluxed to the reaction device, and the liquid is re-proportioned and introduced into the reaction device for reaction.
[0022] Compared with the prior art, the present application has the following advantages: This invention utilizes equal-volume impregnation adsorption to support palladium nanoparticles on a TiO2-SiO2 composite support. The process is simple, environmentally friendly, safe, and easily controllable. The resulting Pd-supported catalyst exhibits good crystallization, displaying a highly dispersed nanoparticle morphology with uniform size and dispersion. Applying this Pd-supported catalyst to the co-production of methyl isobutyl ketone and methyl isopentyl ketone from mixed aldehydes and ketones effectively improves the conversion rate of isobutyraldehyde, enhances selectivity for methyl isopentyl ketone, and reduces organic impurities in the product, simplifying subsequent separation processes. The reaction process is simple, stable, and efficient, allowing for efficient control of the methyl isopentyl ketone ratio to better meet market demands and is suitable for industrial production. Compared to other existing preparation methods, this co-production method offers advantages such as stable catalyst performance, high feed conversion rate, high selectivity for the target product, and low environmental pollution. Attached Figure Description
[0023] Figure 1 This is a scanning electron microscope (5 nm) image of the Pd-supported catalyst prepared in Example 1 of the present invention. Figure 2 This is a scanning electron microscope (SEM) image (100 nm) of the Pd-supported catalyst prepared in Example 1 of the present invention. Detailed Implementation
[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0025] A method for preparing a Pd-supported catalyst, comprising the following steps: S1. Dissolve measured amounts of tetraethyl orthosilicate (TEOS) and tetrabutyl titanate (MSDS) in measured amounts of anhydrous ethanol, stir vigorously, add ammonia to adjust the pH to 8-11, stir vigorously again, age at room temperature for 4-8 hours, and dry in a water bath for 12-18 hours to obtain a mixture. S2. The mixture is extruded into long strips and transferred to a tube furnace for calcination at 300-400℃ for 3-5 hours to obtain TiO2-SiO2 composite carrier; S3. Add measured amount of palladium chloride to a magnetically stirred reactor containing propylene glycol carbonate, purge with hydrogen to a pressure of 1-5 MPa, and carry out a reduction reaction at 50-110℃ for 1-6 h to obtain palladium nanoparticle solution. S4. The measured TiO2-SiO2 composite support is added to the palladium nanoparticle solution of step S3 for equal-volume impregnation and adsorption. After filtration, it is washed three times and dried under vacuum to obtain the Pd supported catalyst.
[0026] The Pd-supported catalyst prepared by the above method is well crystallized, exhibits a highly dispersed nanoparticle morphology, and is uniform in size and dispersion.
[0027] The Pd-supported catalyst was used to catalyze the one-step co-production of methyl isobutyl ketone and methyl isopentyl ketone from a mixture of acetone and isobutyraldehyde.
[0028] Specifically, the method for co-producing methyl isobutyl ketone and methyl isopentyl ketone from mixed aldehydes and ketones includes the following steps: A. Transfer the Pd supported catalyst to a fixed-bed reactor and introduce protective gas N2 into the reactor to check its airtightness. B. With 10,000~20,000h -1 Hydrogen gas is continuously introduced into the middle of the device at a speed of 50-80g / m³. . h -1 A mixed aldehyde-ketone mixture consisting of acetone and isobutyraldehyde in a mass ratio of 3.8 to 4.2:1 is introduced into the top of the device, and the reaction temperature is controlled at 70 to 130°C to promote rapid reaction. C. After the reaction is complete, the reaction solution is filtered through the apparatus's filter. Then, multi-stage condensation is performed using condensation temperatures set according to the boiling points of acetone, isobutyraldehyde, methyl isobutyl ketone, and methyl isopentyl ketone to separate the products methyl isobutyl ketone, methyl isopentyl ketone, and the unreacted mixed aldehydes and ketones. The unreacted mixed aldehydes and ketones are re-proportioned and reintroduced into the reaction apparatus for further reaction. The unreacted gaseous components are condensed, and the gaseous phase is refluxed back into the reaction apparatus. The liquid phase is re-proportioned and reintroduced into the reaction apparatus for further reaction.
[0029] Example 1 A Pd-supported catalyst is prepared according to the following method: S1. Dissolve measured amounts of tetraethyl orthosilicate (TEOS) and tetrabutyl titanate (MSDS) in measured amounts of anhydrous ethanol, stir vigorously, add ammonia to adjust pH to 9, stir vigorously again, age at room temperature for 6 hours, and dry in a water bath for 15 hours to obtain a mixture. S2. The mixture is extruded into long strips and transferred to a tube furnace for calcination at 350°C for 4 hours to obtain TiO2-SiO2 composite carrier; S3. Add the measured amount of palladium chloride to a magnetically stirred tank containing propylene glycol carbonate, purge with hydrogen to a pressure of 3 MPa, and carry out a reduction reaction at 80°C for 4 hours to obtain a palladium nanoparticle solution. S4. Add the measured TiO2-SiO2 composite support to the palladium nanoparticle solution of step S3 for equal volume impregnation and adsorption, filter, wash three times, and vacuum dry to obtain the final product.
[0030] Figure 1 and Figure 2 These are scanning electron microscope (SEM) images of the catalyst prepared in this embodiment at 5 nm and 100 nm. Figure 1 and Figure 2It can be seen that the catalyst prepared in this embodiment is well crystallized, exhibits a highly dispersed nanoparticle morphology, and is uniform in size and dispersion.
[0031] Examples 2-4 The difference between Examples 2-4 and Example 1 is that in step S1, ammonia water is added to adjust the pH to 8, 10, and 11, respectively, while the other steps and conditions are exactly the same as in Example 1.
[0032] Examples 5-7 The differences between Examples 5-7 and Example 1 are as follows: the aging time in step S1 is 5h, 7h and 8h, respectively, while the other steps and conditions are exactly the same as in Example 1.
[0033] Examples 8-13 The differences between Examples 8-13 and Example 1 are as follows: the water bath drying time in step S1 is 12h, 13h, 14h, 16h, 17h and 18h, respectively, while the other steps and conditions are exactly the same as in Example 1.
[0034] Examples 14-15 The difference between Examples 14 and 15 and Example 1 is that the calcination temperature in step S2 is 300℃ and 400℃, respectively, while the other steps and conditions are exactly the same as in Example 1.
[0035] Examples 16-17 The difference between Examples 16 and 17 and Example 1 is that the calcination time in step S2 is 3 hours and 5 hours, respectively, while the other steps and conditions are exactly the same as in Example 1.
[0036] Examples 18-21 The difference between Examples 18-21 and Example 1 is that hydrogen gas is introduced in step S3 to make the pressure 1MPa, 2MPa, 4MPa and 5MPa respectively, while the other steps and conditions are exactly the same as in Example 1.
[0037] Examples 22-23 The difference between Examples 22 and 23 and Example 1 is that the reduction reaction temperature in step S3 is 50°C and 110°C, respectively, while the other steps and conditions are exactly the same as in Example 1.
[0038] Examples 24-29 The difference between Examples 24-29 and Example 1 is that the reduction reaction time in step S3 is 1h, 2h, 3h, 5h and 6h respectively, while the other steps and conditions are exactly the same as in Example 1.
[0039] Comparative Example 1 The difference between this comparative example and Example 1 is that steps S3 and S4 are omitted, and TiO2-SiO2 composite support is used directly as catalyst. The other steps and conditions are exactly the same as in Example 1.
[0040] Comparative Example 2 The difference between this comparative example and Example 1 is that in step S1, only a measured amount of tetrabutyl titanate (MSDS) is dissolved in a measured amount of anhydrous ethanol; all other steps and conditions are exactly the same as in Example 1. The resulting catalyst is palladium nanoparticles supported on a TiO2 support.
[0041] Comparative Example 3 The difference between this comparative example and Example 1 is that in step S1, only a measured amount of tetraethyl orthosilicate (TEOS) is dissolved in a measured amount of anhydrous ethanol; the other steps and conditions are exactly the same as in Example 1. The resulting catalyst is palladium nanoparticles supported on a SiO2 support.
[0042] Comparative Example 4 The difference between this comparative example and Example 1 is that in step S1, only a measured amount of tetraethyl orthosilicate (TEOS) is dissolved in a measured amount of anhydrous ethanol, and steps S3 and S4 are not performed. The SiO2 composite support is used directly as the catalyst, while the other steps and conditions are exactly the same as in Example 1.
[0043] Comparative Example 5 The difference between this comparative example and Example 1 is that in step S1, only a measured amount of tetrabutyl titanate (MSDS) is dissolved in a measured amount of anhydrous ethanol, and steps S3 and S4 are not performed. The TiO2 composite support is used directly as the catalyst, while the other steps and conditions are exactly the same as in Example 1.
[0044] Application Examples The catalysts prepared in Examples 1-29 and Comparative Examples 1-5 were applied to the co-production of methyl isobutyl ketone and methyl isopentyl ketone from mixed aldehydes and ketones. The specific method included the following steps: A. Transfer the Pd supported catalyst to a fixed-bed reactor and introduce protective gas N2 into the reactor to check its airtightness. B. At 15000h -1 Hydrogen gas was continuously introduced into the middle of the device at a space velocity of 60g. . h -1 A mixed aldehyde-ketone mixture of acetone and isobutyraldehyde in a 4:1 mass ratio is introduced into the top of the device, and the reaction temperature is controlled at 100°C to promote rapid reaction. C. After the reaction is complete, the reaction solution is filtered through the apparatus's filter. Then, multi-stage condensation is performed using condensation temperatures set according to the boiling points of acetone, isobutyraldehyde, methyl isobutyl ketone, and methyl isopentyl ketone to separate the products methyl isobutyl ketone, methyl isopentyl ketone, and the unreacted mixed aldehydes and ketones. The unreacted mixed aldehydes and ketones are re-proportioned and reintroduced into the reaction apparatus for further reaction. The unreacted gaseous components are condensed, and the gaseous phase is refluxed back into the reaction apparatus. The liquid phase is re-proportioned and reintroduced into the reaction apparatus for further reaction.
[0045] The selectivity, acetone conversion and isobutyraldehyde conversion of products MIAK and MIBK were calculated at the corresponding time points, and the results are shown in Table 1.
[0046] Table 1. Performance comparison of the catalysts prepared in Examples 1-29 and Comparative Examples 1-7 in the co-production of MIAK and MIBK.
[0047] As shown in Table 1, applying the Pd-supported catalyst prepared in this invention to the co-production of methyl isobutyl ketone and methyl isopentyl ketone from mixed aldehydes and ketones can effectively improve the conversion rate of isobutyraldehyde, improve the selectivity for methyl isopentyl ketone, reduce the organic impurities in the product, simplify the subsequent separation process, and make the reaction process simple, stable and efficient. It can also efficiently control the proportion of methyl isopentyl ketone to better meet market demands and is suitable for industrial production.
[0048] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.
Claims
1. A method for preparing a Pd-supported catalyst, characterized in that: Includes the following steps: S1. Dissolve tetraethyl orthosilicate and tetrabutyl titanate in anhydrous ethanol, stir and adjust the pH, age at room temperature, and then dry to obtain a mixture. S2. The mixture is extruded into long strips and transferred to a tube furnace for calcination to obtain TiO2-SiO2 composite carrier; S3. Add a measured amount of palladium chloride to propylene glycol carbonate, introduce hydrogen gas, and carry out a reduction reaction under magnetic stirring to obtain a palladium nanoparticle solution. S4. The measured TiO2-SiO2 composite support is added to the palladium nanoparticle solution of step S3 for equal-volume impregnation and adsorption. After filtration, washing, and vacuum drying, the Pd supported catalyst is obtained.
2. The method for preparing the Pd-supported catalyst according to claim 1, characterized in that: In step S1, the pH is adjusted to 8-11, and the aging time is 4-8 hours; the drying is water bath drying, and the drying time is 12-18 hours.
3. The method for preparing the Pd-supported catalyst according to claim 1, characterized in that: In step S2, the calcination temperature is 300~400℃ and the calcination time is 3~5h.
4. The method for preparing the Pd-supported catalyst according to claim 1, characterized in that: In step S3, the reduction pressure is 1~5 MPa, the reduction temperature is 50~110℃, and the reduction time is 1~6 h.
5. A Pd-supported catalyst, characterized in that: It is prepared by any one of claims 1 to 4.
6. The application of the Pd-supported catalyst as described in claim 5 in the co-production of methyl isobutyl ketone and methyl isopentyl ketone from mixed aldehydes and ketones.
7. A method for the co-production of methyl isobutyl ketone and methyl isopentyl ketone from mixed aldehydes and ketones, characterized in that: The Pd-supported catalyst as described in claim 5 is used to catalyze the one-step co-production of methyl isobutyl ketone and methyl isopentyl ketone from acetone and isobutyraldehyde.
8. The method for co-producing methyl isobutyl ketone and methyl isopentyl ketone according to claim 7, characterized in that: Includes the following steps: A. Transfer the Pd supported catalyst to a fixed-bed reactor and introduce protective gas N2 into the reactor to check its airtightness; B. Continuously introduce hydrogen gas into the middle of the apparatus and introduce a mixture of acetone and isobutyraldehyde into the top of the apparatus, controlling the reaction temperature at 70~130℃ to promote the rapid reaction. C. After the reaction is complete, the reaction solution is filtered out through the filter of the device, and then the products methyl isobutyl ketone, methyl isopentyl ketone and unreacted mixed aldehydes and ketones are separated by multi-stage condensation.
9. The method for co-producing methyl isobutyl ketone and methyl isopentyl ketone according to claim 8, characterized in that: In step B, the mass ratio of acetone to isobutyraldehyde in the mixed aldehyde and ketone mixture is 3.8~4.2:
1.
10. The method for co-producing methyl isobutyl ketone and methyl isopentyl ketone according to claim 8, characterized in that: In step B, the hydrogen space velocity is 10,000~20,000 h⁻¹. -1 The flow rate of the mixed aldehydes and ketones is 50-80g. . h -1 .