A phosphomolybdic acid-rare earth metal ion / imidazolium-modified UiO-66 composite catalyst, its preparation method and application
By using a phosphomolybdic acid-rare earth metal ion/imidazolium-modified UiO-66 composite catalyst, the problems of low catalytic efficiency, poor selectivity, and environmental pollution in the synthesis of antioxidant 1330 were solved, achieving efficient, green, and low-cost preparation of antioxidant 1330.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QINGDAO UNIV OF SCI & TECH
- Filing Date
- 2025-12-03
- Publication Date
- 2026-06-30
AI Technical Summary
The existing synthesis process for antioxidant 1330 suffers from low catalytic efficiency, poor selectivity, poor catalyst stability, harsh reaction conditions, and environmental pollution problems, failing to meet the demands of modern chemical industry for high efficiency, greenness, and low cost.
A highly selective and high-purity antioxidant 1330 was prepared by using a phosphomolybdic acid-rare earth metal ion/imidazolium-modified UiO-66 composite catalyst, which synergistically activates the reaction pathway through multiple active centers, combined with the enhanced mass transfer and active center dispersion of the MOF support to achieve directional catalysis and stable reaction conditions.
It significantly improves catalytic efficiency and selectivity, reduces reaction energy consumption, enhances catalyst stability and resource utilization, reduces environmental pollution, and lowers production costs.
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of phosphomolybdic acid-rare earth metal ion / imidazolium modified UiO-66 composite catalysts, and specifically relates to a phosphomolybdic acid-rare earth metal ion / imidazolium modified UiO-66 composite catalyst, its preparation method and application. Background Technology
[0002] Antioxidant 1330 is a high molecular weight hindered phenolic antioxidant with the chemical name 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene. It has the characteristics of good heat resistance, strong anti-extraction, and excellent compatibility with polymers. It is widely used in the processing and long-term stabilization of polymer materials such as polyethylene, polypropylene, and ABS resin.
[0003] Currently, the mainstream industrial process for synthesizing antioxidant 1330 is the Friedel-Crafts alkylation reaction of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether with mesitylene. However, this traditional technology has the following prominent problems:
[0004] Low catalytic efficiency: Most catalysts use a single Lewis acid (such as anhydrous AlCl3, ZnCl2) or Brønsted acid (such as concentrated sulfuric acid), resulting in uneven dispersion of active centers and high activation energy (approximately 78 kJ / mol in traditional systems). This leads to a raw material conversion rate of only 85-90%, a target product yield that is generally below 80%, and a reaction time as long as 8-12 hours.
[0005] Poor selectivity: Traditional catalysts cannot precisely control the alkylation substitution sites, and are prone to side reactions such as multiple substitution and isosubstitution, generating mono-substituted and di-substituted impurities and benzyl ether self-polymers. The product purity is only 95-97%, and subsequent distillation purification consumes a lot of energy, which greatly increases the production cost.
[0006] The catalyst structure is not stable enough and is difficult to recover: the active metal of traditional catalysts is easily lost, resulting in the catalyst being unstable and having a high activity decay rate after repeated use; homogeneous catalysts cannot be directly separated from the reaction system and require complex post-treatment such as water washing and neutralization, generating a large amount of acidic wastewater (COD value ≥3000mg / L), causing serious environmental pollution, and the catalyst cannot be recycled, resulting in serious waste of resources;
[0007] The reaction conditions are harsh: some processes need to be carried out at high temperatures of 120-150℃, which consumes a lot of energy and the high temperature can easily lead to the oxidation and degradation of raw materials, further reducing product yield and quality.
[0008] Although researchers have attempted to optimize catalyst types or reaction parameters, none have broken through the technical bottleneck of synergistic improvement in "catalytic efficiency, selectivity, and environmental friendliness," failing to meet the development needs of modern chemical industry for "high efficiency, greenness, and low cost." Therefore, developing a novel catalytic system that combines high activity, high selectivity, easy recyclability, and environmental friendliness is of great significance for promoting the industrial upgrading of antioxidant 1330. Summary of the Invention
[0009] To address the technical problems in the existing antioxidant 1330 synthesis process, such as low product selectivity, poor catalyst stability, and insufficiently mild catalytic reaction, this invention provides a phosphomolybdic acid-rare earth metal ion / imidazolium-modified UiO-66 composite catalyst, its preparation method, and its application.
[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0011] First, this invention provides a phosphomolybdic acid-rare earth metal ion / imidazolium-modified UiO-66 composite catalyst. The catalyst comprises a modified support and an active component supported on the modified support. The modified support is an imidazolium-modified zirconium-based metal-organic framework material UiO-66, denoted as Im-UiO-66. The active component comprises phosphomolybdic acid and rare earth metal ions, wherein the rare earth metal ions are Nd... 3+ 、Sm 3+ Or Eu 3+ One or more.
[0012] Secondly, the present invention provides a method for preparing the above-mentioned composite catalyst, comprising the following steps:
[0013] 2.1) Preparation of Im-UiO-66 support: Zirconium chloride and imidazole-modified terephthalic acid were dissolved in N,N-dimethylformamide and subjected to thermal reaction. After post-treatment, imidazole-modified zirconium-based metal-organic framework material UiO-66 was obtained, abbreviated as support Im-UiO-66.
[0014] 2.2) The phosphomolybdic acid loading was carried out by the equal volume impregnation method. The aqueous solution of phosphomolybdic acid was impregnated in the carrier Im-UiO-66, stirred and impregnated, filtered, dried and calcined to obtain the composite phosphomolybdic acid / Im-UiO-66.
[0015] 2.3) Rare earth metal supported composite phosphomolybdic acid / Im-UiO-66 was impregnated in aqueous solutions of neodymium nitrate, samarium nitrate or europium nitrate, dried, calcined under N2 atmosphere, and then tableted and pulverized after adding binder to obtain composite catalyst phosphomolybdic acid-rare earth metal ions / Im-UiO-66.
[0016] Preferably, in the composite catalyst, the loading of the active component phosphomolybdic acid is 12-20 wt% based on the mass of the modified support; and the loading of the active component rare earth metal ions is 2-5 wt%.
[0017] Preferably, the thermal reaction in step 2.1) is carried out at 120°C for 24 hours.
[0018] Preferably, the stirring and impregnation in step 2.2) is carried out at a temperature of 60-80°C for 8-12 hours.
[0019] Preferably, the impregnation conditions in step 2.3) are: impregnation at room temperature for 12 hours; drying at 60°C for 12 hours; and calcination at 350-400°C for 2-3 hours under a N2 atmosphere.
[0020] This invention also provides the application of the composite catalyst phosphomolybdic acid-rare earth metal ions / Im-UiO-66 in the catalytic synthesis of antioxidant 1330.
[0021] Finally, this invention provides a method for synthesizing antioxidant 1330: 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, mesitylene and a composite catalyst are added to a reaction vessel, the air inside the vessel is replaced with nitrogen, the reaction temperature and time are controlled, and after a post-processing step, antioxidant 1330 is obtained. The separated catalyst can be recycled.
[0022] Preferably, the reaction temperature is controlled at 75-95℃, the stirring speed at 450-650rpm, and the reaction time is 2.5-5h.
[0023] Preferably, the molar ratio of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether to mesitylene is 3.1-3.6:1; the catalyst mass accounts for 1.2-2.8% of the total mass of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether and mesitylene.
[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0025] First, the three-functional synergistic catalytic mechanism improves the catalyst's catalytic efficiency:
[0026] Synergistic activation of the reaction pathway by multiple active sites: Phosphomolybdic acid provides a strong Brønsted acidic site, which precisely activates the benzyl carbon-oxygen bond of 3,5-di-tert-butyl-4-hydroxybenzylmethyl ether through protonation, significantly reducing the bond breaking activation energy from 78 kJ / mol in the traditional system to 32 kJ / mol; The rare earth metal ions provided by this invention can form stable coordination with the benzyl carbocation, regulate the charge distribution of the intermediate, and accelerate its electrophilic substitution reaction with the mesitylene ring; The imidazole functionalized group further reduces the reaction energy barrier through electron transfer, forming a highly efficient catalytic chain of "protonation-coordination stabilization-electronic regulation", which significantly improves the catalytic efficiency of the catalyst.
[0027] MOF support enhances mass transfer and active site dispersion: Im-UiO-66 has an ultra-high specific surface area and a uniform microporous structure, which can uniformly disperse phosphomolybdic acid and rare earth metal ions, fully expose the active sites, and avoid the decrease in catalytic efficiency caused by the aggregation of active sites. At the same time, the regular pore structure constructs efficient mass transfer channels, which can improve the diffusion rate of raw material molecules and reduce the desorption resistance of products, further enhancing the catalytic activity of the catalyst.
[0028] This invention uses phosphomolybdic acid-rare earth metal ions / Im-UiO-66 catalysis to synthesize antioxidant 1330. The raw material conversion rate exceeds 99%, the reaction time is shortened to 2.5-5h, and the efficiency is improved by more than 60% compared with the traditional process (8-12h). The yield of the target product is stable at more than 97.4%, and can reach up to 98.8%, which is 17 percentage points higher than the traditional process (≤80%).
[0029] Second, selective and precise regulation can block side reactions and improve the selectivity of the target product:
[0030] Targeted catalysis blocks side reaction pathways: Rare earth metal ions form specific coordination with the three methyl groups of mesitylene, significantly enriching the electron cloud density at positions 2, 4, and 6 of the mesitylene aromatic ring (more than 30% higher than other sites), guiding the benzyl carbocation to preferentially attack these three target substitution sites. Simultaneously, the pore confinement effect of Im-UiO-66 (pore size 1.5-2.5 nm) effectively blocks the formation of multi-substituted impurities (molecular size ≥ 3 nm), thermodynamically blocking non-target reaction pathways such as mono-substituted, iso-substituted, and benzyl ether self-polymerization. This completely solves the technical pain point of difficult byproduct separation in traditional processes, improving the selectivity of the target product. The selectivity of antioxidant 1330 obtained by this invention jumps from 85-90% in traditional processes to over 98.5%, with a total byproduct content ≤ 0.4%.
[0031] Third, product purity and catalyst stability are improved simultaneously:
[0032] High product purity: Through the synergistic effect of selective control and mild reaction conditions, the product purity directly reaches over 99.6%, with a maximum of 99.9%, eliminating the need for complex multi-stage distillation purification; simple vacuum distillation suffices. Excellent catalyst cycle stability: The rigid framework structure of the Im-UiO-66 support and the "metal-support strong interaction (SMSI)" significantly inhibit the dissolution and loss of phosphomolybdic acid and rare earth metal ions. After 10 cycles, the feed conversion rate remains ≥97%, the selectivity ≥96.5%, and the activity decay rate ≤2.5%, far superior to traditional homogeneous catalysts (which cannot be recycled) and ordinary heterogeneous catalysts (activity decay ≥30% after 3 cycles). The long cycle performance of the catalyst reduces the cost per use to only 1 / 6 of that of traditional processes, significantly lowering production costs and reducing solid waste pollution after catalyst disposal. After roasting, the rare earth metal recovery rate of the spent catalyst is ≥92%, and the phosphomolybdic acid can be recycled, significantly improving resource utilization.
[0033] Fourth, the synthesis reaction conditions for antioxidant 1330 are mild:
[0034] The antioxidant 1330 is synthesized using phosphomolybdic acid-rare earth metal ions / Im-UiO-66 provided by this invention. The reaction temperature can be controlled at 75-95℃, which is 45-75℃ lower than the traditional process (120-150℃). The standard coal consumption per unit product is reduced from 65-75kg / t in the traditional process to 22-32kg / t, and the energy consumption is reduced by more than 65%. No high-temperature heating equipment and insulation facilities are required, nor is high-pressure equipment. The heating energy consumption and equipment maintenance costs are significantly reduced. Detailed Implementation
[0035] This invention discloses a phosphomolybdic acid-rare earth metal ion / imidazolium-modified UiO-66 composite catalyst, its preparation method, and its applications. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired results. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.
[0036] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments.
[0037] Unless otherwise specified, the conversion rate, selectivity of antioxidant 1330, and yield of antioxidant 1330 described in this invention are calculated using the following formulas:
[0038] Conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether = {n(initial 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether) - n(remaining 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether)} / n(initial 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether); 1-1
[0039] Antioxidant 1330 selectivity = 3n(antioxidant 1330) / {n(initial 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether) - n(remaining 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether)}; 1-2
[0040] Antioxidant 1330 yield = 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether conversion × Antioxidant 1330 selectivity; 1-3
[0041] In the above formula, n refers to the amount of substance.
[0042] Example 1: Composite catalyst phosphomolybdic acid-Nd 3+ Preparation and catalytic reaction of / Im-UiO-66
[0043] Catalyst preparation:
[0044] (1) Weigh 10g of zirconium chloride and 12g of imidazole-functionalized terephthalic acid and dissolve them in 150mL of DMF. React at 120℃ for 24h. After centrifugation, wash with DMF and ethanol three times alternately and dry under vacuum at 100℃ for 12h to obtain Im-UiO-66 carrier.
[0045] (2) Take 5g of the above carrier, immerse it in an aqueous solution containing 1.0g of phosphomolybdic acid, stir and immerse at 70°C for 10h, filter and dry, and calcine at 300°C for 2.5h to obtain 20wt% phosphomolybdic acid / Im-UiO-66 complex.
[0046] (3) The composite was impregnated in an aqueous solution containing 0.2 g of neodymium nitrate for 12 h at room temperature; dried at 60 °C for 12 h; calcined at 380 °C in a N2 atmosphere for 2.5 h; 0.2 g of hydroxypropyl methylcellulose was added; the mixture was compressed into tablets and pulverized to 30 mesh to obtain the composite catalyst phosphomolybdic acid-Nd 3+ / Im-UiO-66(Nd 3+ The load is 4wt%.
[0047] Catalytic reaction:
[0048] Add 50g of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, 12g of mesitylene (molar ratio 3.2:1), and 1.1g of the composite catalyst prepared in this example to a 200mL reactor. Then add 50mL of dichloromethane, purge twice with nitrogen, control the reaction temperature at 85℃ and the stirring rate at 550rpm, and react for 3.5h. After the reaction is completed, cool to room temperature, and directly separate the catalyst by filtration for subsequent recycling. The filtrate is purified by vacuum distillation (vacuum degree controlled at 0.09-0.1MPa, temperature controlled at 180-200℃) to obtain antioxidant 1330 product.
[0049] In this embodiment, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 99.8%, the selectivity of antioxidant 1330 was 98.9%, and the yield of antioxidant 1330 was 98.7%; the product purity was 99.9%; after the catalyst was recycled 10 times, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 97.8%, and the selectivity of antioxidant 1330 was 96.8%.
[0050] Example 2 Composite catalyst phosphomolybdic acid-Sm 3+ Preparation and catalytic reaction of / Im-UiO-66
[0051] Catalyst preparation:
[0052] (1) Weigh 10g of zirconium chloride and 12g of imidazole-functionalized terephthalic acid and dissolve them in 150mL of DMF. React at 120℃ for 24h. After centrifugation, wash with DMF and ethanol three times alternately and dry under vacuum at 100℃ for 12h to obtain Im-UiO-66 carrier.
[0053] (2) Take 5g of the above carrier, immerse it in an aqueous solution containing 0.7g of phosphomolybdic acid, stir and immerse at 60°C for 12h, filter and dry, and calcine at 280°C for 3h to obtain 14wt% phosphomolybdic acid / Im-UiO-66 complex.
[0054] (3) The above composite was impregnated in an aqueous solution containing 0.125 g of samarium nitrate for 12 h at room temperature; dried at 60 °C for 12 h; calcined at 350 °C in a N2 atmosphere for 3 h; 0.15 g of hydroxypropyl methylcellulose was added; the mixture was compressed into tablets and pulverized to 20 mesh to obtain the composite catalyst phosphomolybdic acid-Sm 3+ / Im-UiO-66 (Sm 3+ The loading rate is 2.5 wt%.
[0055] Catalytic reaction:
[0056] Add 45g of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, 11g of mesitylene (molar ratio 3.1:1), and 0.8g of the composite catalyst prepared in this example to a 500mL reactor. Then add 50mL of dichloromethane, purge twice with nitrogen, control the reaction temperature at 75℃ and the stirring speed at 450rpm, and react for 5h. After the reaction is completed, cool to room temperature, and directly separate the catalyst by filtration for subsequent recycling. The filtrate is purified by vacuum distillation (vacuum degree controlled at 0.09-0.1MPa, temperature controlled at 180-200℃) to obtain antioxidant 1330 product.
[0057] In this embodiment, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 99.3%, the selectivity of antioxidant 1330 was 98.5%, and the yield of antioxidant 1330 was 97.8%; the purity of the product antioxidant 1330 was 99.6%; after the catalyst was recycled 10 times, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 97.2%, and the selectivity of antioxidant 1330 was 96.3%.
[0058] Example 3 Composite catalyst phosphomolybdic acid-Eu 3+ Preparation and catalytic reaction of / Im-UiO-66
[0059] Catalyst preparation:
[0060] (1) Weigh 10g of zirconium chloride and 12g of imidazole-functionalized terephthalic acid and dissolve them in 150mL of DMF. React at 120℃ for 24h. After centrifugation, wash with DMF and ethanol three times alternately and dry under vacuum at 100℃ for 12h to obtain Im-UiO-66 carrier.
[0061] (2) Take 5g of the above carrier, immerse it in an aqueous solution containing 0.85g of phosphomolybdic acid, stir and immerse at 80°C for 8h, filter and dry, and calcine at 320°C for 2h to obtain a 17wt% phosphomolybdic acid / Im-UiO-66 complex.
[0062] (3) The above composite was impregnated in an aqueous solution containing 0.25 g europium nitrate for 12 h at room temperature; dried at 60 °C for 12 h; calcined at 400 °C in a N2 atmosphere for 2 h; 0.25 g hydroxypropyl methylcellulose was added; the mixture was compressed into tablets and pulverized to 40 mesh to obtain the composite catalyst phosphomolybdic acid-Eu 3+ / Im-UiO-66 (Eu 3+ (Loading amount is 5wt%)
[0063] Catalytic reaction:
[0064] Add 55g of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, 13g of mesitylene (molar ratio 3.6:1), and 1.5g of the catalyst in this example to a 500mL reactor. Then add 50mL of dichloromethane, purge with nitrogen three times, control the reaction temperature at 95℃ and the stirring speed at 650rpm, and react for 2.5h. After the reaction is completed, cool to room temperature, and directly separate the catalyst by filtration for subsequent recycling. The filtrate is purified by vacuum distillation (vacuum degree controlled at 0.09-0.1MPa, temperature controlled at 180-200℃) to obtain antioxidant 1330 product.
[0065] In this embodiment, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 99.9%, the selectivity of antioxidant 1330 was 98.7%, the yield was 98.6%, the product purity was 99.8%, and after the catalyst was recycled 10 times, the conversion rate was 97.9% and the selectivity was 97.0%.
[0066] Example 4: Low phosphomolybdic acid loading catalyst Nd 3+ Preparation and catalytic reaction of / Im-UiO-66
[0067] Catalyst preparation:
[0068] (1) Prepare the Im-UiO-66 carrier in the same manner as in Example 1, step (1);
[0069] (2) Take 5g of the above carrier, immerse it in an aqueous solution containing 0.6g of phosphomolybdic acid, stir and immerse at 70°C for 10h, filter and dry, and calcine at 300°C for 2.5h to obtain 12wt% phosphomolybdic acid / Im-UiO-66 complex.
[0070] (3) The composite was impregnated in an aqueous solution containing 0.15 g of neodymium nitrate for 12 h at room temperature; dried at 60 °C for 12 h; calcined at 380 °C in a N2 atmosphere for 2.5 h; 0.2 g of hydroxypropyl methylcellulose was added; the mixture was compressed into tablets and pulverized to 30 mesh to obtain the composite catalyst phosphomolybdic acid-Nd 3+ / Im-UiO-66(Nd 3+ The load is 3wt%.
[0071] Catalytic reaction:
[0072] Add 48g of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, 12g of mesitylene (molar ratio 3.3:1), and 1.0g of the catalyst in this example to a 500mL reactor. Then add 50mL of dichloromethane, purge twice with nitrogen, control the reaction temperature at 80℃ and the stirring speed at 500rpm, and react for 4h. After the reaction is completed, cool to room temperature, and directly separate the catalyst by filtration for subsequent recycling. The filtrate is purified by vacuum distillation (vacuum degree controlled at 0.09-0.1MPa, temperature controlled at 180-200℃) to obtain antioxidant 1330 product.
[0073] In this example, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 99.1%, the selectivity of antioxidant 1330 was 98.3%, and the yield of antioxidant 133 was 97.4%; the purity of the product antioxidant 133 was 99.5%; after the catalyst was recycled 10 times, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 96.9%, and the selectivity of antioxidant 133 was 96.1%.
[0074] Example 5: Preparation and catalytic reaction of the composite rare earth metal supported catalyst Im-UiO-66
[0075] Catalyst preparation:
[0076] (1) Prepare the Im-UiO-66 carrier in the same manner as in Example 1, step (1);
[0077] (2) Take 5g of the above carrier, immerse it in an aqueous solution containing 1.0g of phosphomolybdic acid, stir and immerse at 70°C for 10h, filter and dry, and calcine at 300°C for 2.5h to obtain 20wt% phosphomolybdic acid / Im-UiO-66 complex.
[0078] (3) The composite was impregnated in a mixed aqueous solution containing 0.1 g neodymium nitrate and 0.1 g samarium nitrate for 12 h at room temperature; dried at 60 °C for 12 h; calcined at 380 °C under N2 atmosphere for 2.5 h; 0.2 g hydroxypropyl methylcellulose was added; and the mixture was compressed into tablets and pulverized to 30 mesh to obtain the composite catalyst phosphomolybdic acid-Nd 3+ -Sm 3+ / Im-UiO-66(Nd 3+ and Sm 3+ The total load is 4wt%.
[0079] Catalytic reaction:
[0080] Add 50g of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, 12g of mesitylene (molar ratio 3.2:1), and 1.1g of the catalyst in this example to a 500mL reactor. Then add 50mL of dichloromethane, purge twice with nitrogen, and control the reaction temperature at 85℃ and the stirring speed at 550rpm for 3.5h. After the reaction is completed, cool to room temperature, and directly separate the catalyst by filtration for subsequent recycling. The filtrate is purified by vacuum distillation (vacuum degree controlled at 0.09-0.1MPa, temperature controlled at 180-200℃) to obtain antioxidant 1330 product.
[0081] In this embodiment, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 99.7%, the selectivity of antioxidant 1330 was 99.1%, and the yield of antioxidant 1330 was 98.8%; the purity of the product antioxidant 1330 was 99.9%; after the catalyst was recycled 10 times, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 98.1%, and the selectivity of antioxidant 1330 was 97.3%.
[0082] Example 6 Composite Catalyst Eu 3+ Preparation and catalytic reaction of / Im-UiO-66
[0083] Catalyst preparation:
[0084] (1) Prepare the Im-UiO-66 carrier in the same manner as in Example 3 (1);
[0085] (2) Take 5g of the above carrier, immerse it in an aqueous solution containing 0.85g of phosphomolybdic acid, stir and immerse at 80°C for 8h, filter and dry, and calcine at 320°C for 2h to obtain a 17wt% phosphomolybdic acid / Im-UiO-66 complex.
[0086] (3) The composite was impregnated in an aqueous solution containing 0.25 g europium nitrate for 12 h at room temperature; dried at 60 °C for 12 h; calcined at 400 °C in a N2 atmosphere for 2 h; 0.25 g hydroxypropyl methylcellulose was added; the mixture was compressed into tablets and pulverized to 40 mesh to obtain the composite catalyst phosphomolybdic acid-Eu 3+ / Im-UiO-66 (Eu 3+ (Loading capacity 5wt%).
[0087] Catalytic reaction:
[0088] Add 55g of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, 13g of mesitylene (molar ratio 3.6:1), and 0.8g of the catalyst in this example to a 500mL reactor. Then add 50mL of dichloromethane, purge with nitrogen three times, control the reaction temperature at 95℃ and the stirring speed at 650rpm, and react for 3h; react for 5h. After the reaction is completed, cool to room temperature, and directly separate the catalyst by filtration for subsequent recycling. The filtrate is purified by vacuum distillation (vacuum degree controlled at 0.09-0.1MPa, temperature controlled at 180-200℃) to obtain antioxidant 1330 product.
[0089] In this embodiment, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 99.2%, the selectivity of antioxidant 1330 was 98.6%, and the yield of antioxidant 1330 was 97.8%; the purity of the product antioxidant 1330 was 99.6%; after the catalyst was recycled 10 times, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 97.3%, and the selectivity of antioxidant 1330 was 96.5%.
[0090] Comparative Example 1: Catalyst supported on unmodified UiO-66 support and catalytic reaction
[0091] Catalyst preparation: Except for the preparation of pure UiO-66 support using unmodified terephthalic acid, the remaining steps were the same as in Example 1 to obtain the catalyst phosphomolybdic acid-Nd 3+ / UiO-66;
[0092] Catalytic reaction: Same reaction conditions as in Example 1;
[0093] In Comparative Example 1, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 92.1%, the selectivity of antioxidant 1330 was 90.3%, and the yield of antioxidant 1330 was 83.2%; the purity of the product antioxidant 1330 was 96.2%. After the catalyst in this comparative example was recycled 3 times, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether decreased to 84.5%, and the selectivity of antioxidant 1330 was 87.1%.
[0094] Comparative Example 2: Nd-based catalyst without phosphomolybdic acid 3+ / Im-UiO-66 and catalytic reaction
[0095] Catalyst preparation: Except for the absence of phosphomolybdic acid, the remaining steps were the same as in Example 1 to obtain the composite catalyst Nd. 3+ / Im-UiO-66;
[0096] Catalytic reaction: The composite catalyst Nd from Comparative Example 2 was used. 3+ / Im-UiO-66 was used for catalytic reaction, and the reaction conditions and steps were the same as in Example 1;
[0097] The conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether in Comparative Example 2 was 91.5%, the selectivity of antioxidant 1330 was 88.7%, and the yield of antioxidant 1330 was 81.2%. The purity of the product antioxidant 1330 was 92.8%, and the content of monosubstituted and disubstituted impurities reached 6.5%.
[0098] Comparative Example 3: Rare Earth Metal-Free Supported Catalyst Phosphomolybdic Acid / Im-UiO-66 and Catalytic Reaction
[0099] Catalyst preparation: Except for not supporting rare earth metals, the other steps are the same as in Example 1 to obtain the composite catalyst phosphomolybdic acid / Im-UiO-66;
[0100] Catalytic reaction: The composite catalyst phosphomolybdic acid / Im-UiO-66 of Comparative Example 3 was used for catalytic reaction, and the reaction conditions and steps were the same as in Example 1;
[0101] In Comparative Example 3, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether was 82.1%, the selectivity of antioxidant 1330 was 80.3%, and the yield of antioxidant 1330 was 73.2%; the purity of antioxidant 1330 in the product was 76.2%. After the catalyst in this comparative example was recycled 3 times, the conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether decreased to 74.5%, and the selectivity of antioxidant 1330 was 67.1%.
[0102] Comparative Example 4: Traditional anhydrous AlCl3 homogeneous catalytic process
[0103] Catalytic reaction: 50g of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, 12g of mesitylene (molar ratio 3.2:1), and 3.0g of commercially available anhydrous AlCl3 were added to a 500mL reactor. The reaction temperature was controlled at 130℃ and the stirring speed at 500rpm for 10h. After the reaction was completed, the mixture was neutralized with 10% hydrochloric acid aqueous solution, washed three times with water, and purified by distillation after separation to obtain antioxidant 1330.
[0104] The conversion rate of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether in Comparative Example 3 was 88.5%, the selectivity of antioxidant 1330 was 86.4%, and the yield of antioxidant 1330 was 76.5%; the purity of the product antioxidant 1330 was 95.7%; 85 mL of acidic wastewater (COD=3600 mg / L) was generated; the catalyst could not be recovered and needed to be added at once.
[0105] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A phosphomolybdic acid-rare earth metal ion / imidazolium-modified UiO-66 composite catalyst, characterized in that, The product includes a modified support and an active component loaded on the modified support. The modified support is an imidazole-modified zirconium-based metal-organic framework material, UiO-66, denoted as Im-UiO-66. The active component includes phosphomolybdic acid and rare earth metal ions, wherein the rare earth metal ions are Nd2+. 3+ 、Sm 3+ Or Eu 3+ One or more of them.
2. The method for preparing the composite catalyst as described in claim 1, characterized in that, Includes the following steps: 2.1) Preparation of Im-UiO-66 support: Zirconium chloride and imidazole-modified terephthalic acid were dissolved in N,N-dimethylformamide and subjected to thermal reaction. After post-treatment, imidazole-modified zirconium-based metal-organic framework material UiO-66 was obtained, abbreviated as support Im-UiO-66. 2.2) The phosphomolybdic acid loading was carried out by the equal volume impregnation method. The aqueous solution of phosphomolybdic acid was impregnated in the carrier Im-UiO-66, stirred and impregnated, filtered, dried and calcined to obtain the composite phosphomolybdic acid / Im-UiO-66. 2.3) Rare earth metal supported composite phosphomolybdic acid / Im-UiO-66 was impregnated in aqueous solutions of neodymium nitrate, samarium nitrate or europium nitrate, dried, calcined under N2 atmosphere, and then tableted and pulverized after adding binder to obtain composite catalyst phosphomolybdic acid-rare earth metal ions / Im-UiO-66.
3. The preparation method according to claim 2, characterized in that, In the composite catalyst, the loading of the active component phosphomolybdic acid is 12-20 wt% based on the mass of the modified support; the loading of the active component rare earth metal ions is 2-5 wt%.
4. The preparation method according to claim 2, characterized in that, The thermal reaction in step 2.1) is a thermal reaction at 120°C for 24 hours.
5. The preparation method according to claim 2 or 4, characterized in that, The stirring and impregnation in step 2.2) is carried out at a temperature of 60-80℃ for 8-12 hours.
6. The preparation method according to claim 2 or 4, characterized in that, The following conditions are included: the impregnation conditions in step 2.3) are: impregnation at room temperature for 12 hours; drying at 60°C for 12 hours; and calcination at 350-400°C for 2-3 hours under a N2 atmosphere.
7. The application of the composite catalyst as described in claim 1 or the composite catalyst prepared by any of the preparation methods described in claims 2-6 in the catalytic synthesis of antioxidant 1330.
8. The application as described in claim 7, characterized in that: The synthesis method of antioxidant 1330 is as follows: 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether, mesitylene and composite catalyst are added to a reaction vessel, the air in the vessel is replaced with nitrogen, the reaction temperature and time are controlled, and antioxidant 1330 is obtained after post-processing steps. The separated catalyst can be recycled.
9. The application as described in claim 8, characterized in that: Control the reaction temperature at 75-95℃, the stirring speed at 450-650rpm, and the reaction time at 2.5-5h.
10. The application as described in claim 8, characterized in that: The molar ratio of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether to mesitylene is 3.1-3.6:1; the catalyst accounts for 1.2-2.8% of the total mass of 3,5-di-tert-butyl-4-hydroxybenzyl methyl ether and mesitylene.