Metal-molecular sieve bifunctional catalyst for catalyzing 5-hydroxymethylfurfural to prepare 3-hydroxymethylcyclopentanone as well as preparation method and application of metal-molecular sieve bifunctional catalyst
By constructing bifunctional catalysts using non-precious metals such as Ni, Co, and Cu on modified molecular sieve supports, the problems of high cost of precious metal catalysts and environmental pollution of homogeneous catalysts were solved, achieving efficient conversion of HMF to HCPN with high selectivity and stability.
Patent Information
- Application Number
- CN202511699733.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-01-27
AI Technical Summary
In existing technologies, precious metal catalysts are expensive and not conducive to industrial application, homogeneous acid catalysts have problems such as product separation difficulties and environmental pollution, and single molecular sieve acid centers are difficult to efficiently drive the conversion of HMF to HCPN.
Metal-molecular sieve bifunctional catalysts are constructed by using non-precious metals such as Ni, Co, and Cu with MFI, BEA, or MOR molecular sieve supports modified by hydrothermal dealumination or chemical silanization. By precisely matching the hydrogenation performance of the metal with the acidity of the molecular sieve, the efficient and highly selective conversion of HMF to HCPN is achieved.
It achieves reduced catalyst cost, excellent catalytic performance, good stability, long catalyst life, high atom economy, avoids environmental pollution, HMF conversion rate exceeds 95%, and HCPN selectivity exceeds 90%.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the fields of high-value utilization of biomass resources and catalytic chemistry technology, specifically relating to a metal-molecular sieve bifunctional catalyst for the preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural, its preparation method, and its application. Background Technology
[0002] With the increasing depletion of fossil resources and the intensification of environmental problems, the development and utilization of renewable biomass resources to produce fuels and chemicals has become a global research hotspot. 5-Hydroxymethylfurfural (HMF) is considered an important bridge compound connecting biomass carbohydrates and petrochemicals, and can be obtained by dehydrating sugars such as cellulose, glucose, and fructose. How to efficiently and selectively convert HMF into high-value-added downstream chemicals is key to achieving biomass refining.
[0003] 3-Hydroxymethylcyclopentanone (HCPN) is an important organic synthesis intermediate. Its molecule contains both carbonyl and hydroxyl groups, exhibiting high reactivity and making it suitable for synthesizing fragrances, pharmaceuticals, pesticides, and high-performance polymers. Currently, the main routes for preparing HCPN from HMF involve hydrogenation and ring-opening rearrangement steps. This reaction pathway is complex and may involve various side reactions such as over-hydrogenation, polymerization, and hydrolysis, thus placing extremely high demands on catalyst design.
[0004] In existing technologies, noble metal (such as Au, Pt, Pd, Ru) based catalysts or homogeneous acid catalysts have been reported to achieve this conversion. For example, Ohyama et al. used Au (Ohyama J et al., Chem. Commun. 2014, 50(42): 5633-5636) and Pt (Ohyama J et al., Green Chem. 2016, 18(3): 676-680), and Li et al. used Pd (Li X et al., JCatal. 2019, 378: 201-208) and other noble metal catalysts. Although they can obtain a certain HCPN yield, the high cost of noble metals is not conducive to industrial application. Other studies have used homogeneous Lewis acid (such as AlCl3) catalysts, but there are problems such as difficult product separation, inability to recycle catalysts, and environmental pollution.
[0005] Molecular sieves are widely used as solid acid catalysts due to their regular pore structure, tunable acidity, and excellent hydrothermal stability. However, a single acidic center in a molecular sieve is insufficient to efficiently drive the complete tandem reaction from HMF to HCPN (requiring synergistic hydrogenation and acid catalysis). Coupled with non-noble metals (such as Ni and Co) to molecular sieves to construct metal-acid bifunctional catalysts promises to reduce costs while achieving precise control of the reaction pathway. Currently, accurately matching the hydrogenation performance of the metal with the acidity (including type, strength, and number) of the molecular sieve to achieve efficient and highly selective conversion of HMF to HCPN remains a critical technical challenge to be solved in this field. Summary of the Invention
[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-cost, highly active, selective and stable metal-molecular sieve bifunctional catalyst for the efficient catalytic preparation of HCPN from HMF.
[0007] The objective of this invention is achieved through the following technical solution: A metal-molecular sieve bifunctional catalyst for the preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural, characterized in that the catalyst is composed of an active metal component and a molecular sieve support; The active metal component is at least one of Ni, Co, and Cu; The molecular sieve support is an MFI, BEA, or MOR structured molecular sieve modified by hydrothermal dealumination or chemical silanization, with a molar ratio of Brønsted acid to Lewis acid of 0.1 to 1.5 and a total acid content of 0.1 to 0.8 mmol / g.
[0008] Preferably, based on the total mass of the catalyst, the loading of the active metal component is 0.5 wt.% to 15 wt.%; the MFI, BEA or MOR structured molecular sieve is at least one of HZSM-5 and HBeta.
[0009] Preferably, the silicon-to-aluminum ratio (i.e., the molar ratio of SiO2 / Al2O3) of the molecular sieve support is 20-150; the molar ratio of Brønsted acid to Lewis acid is 0.1-0.8; and the total acid content is 0.1-0.5 mmol / g.
[0010] The present invention discloses a method for preparing a metal-molecular sieve bifunctional catalyst for the preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural, characterized by comprising the following steps: (1) Modification of molecular sieve support: The original molecular sieve is subjected to hydrothermal dealumination or chemical silanization to obtain a modified molecular sieve support with a specific B / L acid ratio. (2) Metal loading: The solution containing the active metal precursor is added dropwise to the modified molecular sieve support obtained in step (1), and loading is carried out by the equal volume impregnation method; (3) Calcination and reduction: The sample obtained in step (2) is dried and then calcined in an air atmosphere, and then reduced in a reducing atmosphere to obtain the bifunctional catalyst.
[0011] Preferably, in step (1), The hydrothermal dealuminization process is as follows: the molecular sieve is treated in a steam atmosphere at 500-700℃ for 1-10 hours to obtain a modified molecular sieve carrier; or, the molecular sieve is treated in a steam atmosphere at 500-700℃ for 1-10 hours, then acid-washed to remove some of the non-framework aluminum, and dried to obtain a modified molecular sieve carrier. The chemical silanization process involves mixing a molecular sieve with a silanizing reagent, refluxing the reaction, filtering, washing, and drying to obtain a modified molecular sieve support.
[0012] Preferably, in step (1), during the hydrothermal dealuminization process, the pickling is performed using 0.1~0.5M hydrochloric acid at 50~100℃ for 1~5 hours; In the chemical silanization process, the silanizing agent is a 0.1-1M hexamethyldisilazane-hexane solution, and the reflux reaction conditions are 30-80°C for 3-10 hours.
[0013] Preferably, in step (2), the solution containing the active metal precursor is at least one of the corresponding metal nitrate aqueous solution, acetate aqueous solution, and chloride aqueous solution; after the addition is completed, it is left to stand at room temperature for 10 to 24 hours.
[0014] Preferably, in step (3), the calcination temperature is 300-600℃ and the calcination time is 1-6 hours; the reducing atmosphere is hydrogen, the reduction temperature is 300-500℃ and the time is 2-6 hours.
[0015] The application of the bifunctional catalyst described in this invention in the catalytic preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural.
[0016] Preferably, the bifunctional catalyst is added to a 5-hydroxymethylfurfural solution, and after the air in the reaction environment is purged, hydrogen gas is introduced to an initial pressure of 1.0~2.0 MPa. The mixture is then stirred at a speed of 1000~5000 rpm and heated to 100~180℃ for 3~6 hours. The amount of the bifunctional catalyst added is 20~60 wt% of 5-hydroxymethylfurfural. It also includes a method for recovering the catalyst: the catalyst after the reaction is recovered, washed, dried and calcined, and then regenerated at 300~500℃ for 1~5 hours in H2 atmosphere before being used directly in the next round of reaction.
[0017] Technical solution and innovation of this invention: The core of this invention lies in the discovery and verification that a specific ratio (B / L ratio) of Brønsted acid to Lewis acid in the molecular sieve support is crucial for the selective conversion of HMF to HCPN. To achieve this specific acidity match, this invention employs two effective molecular sieve modification methods: (1) Hydrothermal dealuminization: Hydrogen-type molecular sieves (such as HZSM-5) are treated in a high-temperature (500-700℃) steam atmosphere for 1-10 hours. This process can selectively remove framework aluminum by acid washing, which not only creates mesopores to improve mass transfer efficiency, but also significantly reduces strong Brønsted acid sites and generates abundant Lewis acid sites (such as EFAL species), thereby reducing the B / L ratio.
[0018] (2) Chemical silanization: Silanizing reagents such as hexamethyldisilazane react with the silanol and aluminol hydroxyl groups on the surface of the molecular sieve. This process can preferentially passivate Brønsted acid sites, and the introduced silane groups may generate new weak Lewis acid sites, thereby precisely lowering the B / L ratio.
[0019] Using the above method, we controlled the B / L ratio of the molecular sieve within an optimal range of 0.1 to 1.5, and the total acid content within 0.1 to 0.8 mmol / g. When combined with a supported non-noble metal (such as Ni), the moderate metal hydrogenation activity and the optimized acidity produce a synergistic effect: the metal site first rapidly hydrogenates the aldehyde group in the HMF, and the generated intermediate undergoes efficient Piancatelli rearrangement ring opening under the dominance of the L acid, while an appropriate amount of B acid may promote the necessary protonation step in the reaction process, ultimately leading to the highly selective formation of HCPN.
[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. Significantly reduced catalyst costs: The use of non-precious metals such as Ni, Co, and Cu to replace precious metals (Pt, Pd, Ru) has significantly reduced catalyst costs, laying the foundation for industrial applications.
[0021] 2. Excellent catalytic performance: Through careful design, the hydrogenation sites of the metal and the acidic sites of the molecular sieve (especially the synergy of Brønsted acid and Lewis acid) are optimally matched, which can efficiently drive the "hydrogenation-ring opening-rearrangement" series reaction, achieving high conversion rate of HMF (>95%) and high selectivity of HCPN (>90%).
[0022] 3. Good catalyst stability: Molecular sieve supports have excellent hydrothermal stability, making them particularly suitable for aqueous reaction systems. They also have long catalyst life and high reusability.
[0023] 4. Atom Economy and Environmental Friendlyness: This catalytic process achieves direct and highly selective conversion from biomass derivatives to high-value chemicals, resulting in high atom economy. The use of a solid catalyst avoids the separation difficulties and environmental pollution problems associated with homogeneous catalysts.
[0024] 5. Highly innovative: The core innovation of this invention lies in revealing the synergistic mechanism between metal hydrogenation and molecular sieve acidity (especially the modified B / L acid ratio), and successfully applying it to the specific and challenging conversion pathway from HMF to HCPN, providing a new catalyst system and technical route for the high-value utilization of biomass resources. Attached Figure Description
[0025] Figure 1 The image shows the XRD diffraction pattern of catalyst 1 in the example.
[0026] Figure 2 The graph shows the cycle stability test results for catalyst 1 in the examples. Detailed Implementation
[0027] The present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.
[0028] Example 1 Molecular sieve support modification and characterization 1. Carrier A1 (modified HZSM-5): HZSM-5 with a silicon-to-aluminum ratio of 50 was treated at 600℃ and 100% steam for 4 hours to perform hydrothermal dealuminization.
[0029] 2. Carrier A2 (modified HZSM-5): Take carrier A1, wash it with 0.1M HCl solution at 80℃ for 2 hours to remove some non-framework aluminum, and then dry it.
[0030] 3. Carrier B (modified HBeta): HBeta with a silicon-to-aluminum ratio of 25 was mixed with a 0.5 mol / L solution of hexamethyldisilazane-hexane and reacted under reflux at 50°C for 6 hours to carry out chemical silanization. After the reaction, the mixture was filtered, washed, and dried.
[0031] 4. Carrier C (unmodified HZSM-5): For comparison, original HZSM-5 (SiO2 / Al2O3=50) was used.
[0032] Acidity characterization: The acidity of the above support was characterized by pyridine adsorption infrared spectroscopy (Py-IR) and ammonia temperature-programmed desorption (NH3-TPD). The results are shown in the table below: .
[0033] Catalyst preparation Catalyst 1 (A1 as support): Weigh 2.0 g of molecular sieve support A1 after hydrothermal dealumination. Prepare a 0.5 mol / L nickel nitrate (Ni(NO3)2·6H2O) aqueous solution and slowly add it dropwise to the A1 powder using an equal-volume impregnation method. Let it stand at room temperature for 12 hours. Then dry it at 110℃ for 12 hours, and then calcine it at 500℃ for 4 hours in air atmosphere. Finally, reduce the calcined sample at 400℃ for 4 hours in pure H2 atmosphere to obtain a Ni / A1 catalyst with a loading of 5 wt.%. Its XRD powder diffraction pattern is shown below. Figure 1 As shown.
[0034] Catalyst 2 (A2 is the support): The preparation method is the same as that of catalyst 1, except that the support is replaced with A2.
[0035] Catalyst 3 (B is the support): The preparation method is the same as that of catalyst 1, except that the support is replaced with B.
[0036] Catalyst 4 (comparative example, with unmodified HZSM-5 as support): The preparation method is the same as that of catalyst 1, except that the support is replaced with C.
[0037] Catalyst 5 (comparative example, with amorphous SiO2-Al2O3 as support): The preparation method is the same as that of catalyst 1, except that the support is replaced with amorphous SiO2-Al2O3 (B / L ratio is about 0.05, and the total acid content is 0.45 mmol / g).
[0038] Catalyst 6 (comparative example, Pt supported on A1 support): It was prepared by loading chloroplatinic acid (H2PtCl6·6H2O) onto A1 support by an equal volume impregnation method with a loading of 1 wt.%, followed by drying, calcination and reduction.
[0039] Catalyst 7 (Comparative example, physical mixing of Ni / SiO2 and Al support): The preparation method is the same as that of catalyst 1, except that the support is replaced with inert SiO2 to obtain a 5 wt.% Ni / SiO2 catalyst. Then, it is physically mixed with Al support at a metal to molecular sieve mass ratio of 1:20 and thoroughly ground to obtain catalyst 7.
[0040] Catalyst 8 (comparative example, Co supported on Al support): The preparation method is the same as that of catalyst 1, except that the metal precursor is replaced with cobalt nitrate (Co(NO3)2·6H2O).
[0041] Catalytic performance evaluation The HMF catalytic conversion reaction was carried out in a 100 mL high-pressure reactor. 0.2 g of HMF, 40 mL of deionized water as solvent, and 0.1 g of the prepared catalyst were added to the reactor. The reactor was sealed and purged three times with argon gas to remove all air. Then, high-purity hydrogen was introduced to an initial pressure of 2.0 MPa, stirring was started (1000 rpm), and the temperature was raised to 150 °C for 4 hours.
[0042] After the reaction was complete, the reaction vessel was cooled to room temperature, the reaction solution was removed, centrifuged, and the supernatant was collected. The product composition was analyzed by high-performance liquid chromatography (HPLC), and the conversion rate of HMF and the selectivity of each product were calculated. The results are shown in the table below:
[0043] Results Analysis and Conclusions: 1. The decisive role of the B / L ratio. Catalysts 1, 2, and 3 (B / L ratios in the range of 0.27-0.70) all achieved excellent HCPN selectivity exceeding 92%. However, comparative catalyst 4 (B / L = 1.67, excessively strong Brønsted acid) led to severe condensation and polymerization of HMF or intermediates, resulting in a significant decrease in selectivity to 70.3%. Comparative catalyst 5 (B / L = 0.05, almost entirely L-acid), while inhibiting polymerization, suffered from an incomplete reaction pathway due to the lack of necessary Brønsted acid assistance, and the potential for over-hydrogenation at the metal sites under weakly acidic conditions, resulting in the lowest HCPN selectivity (55.4%). This clearly demonstrates that controlling the B / L ratio within the range of 0.1-1.5, especially 0.2-0.7, is crucial for achieving high selectivity.
[0044] 2. Matching of Metal Hydrogenation Activity and Support Acidity: Catalyst 6 uses the noble metal Pt. Although it achieves high HMF conversion, its excessively strong metal hydrogenation ability leads to a significant reduction in selectivity as a large amount of HCPN is further hydrogenated to form byproducts. Catalyst 8 uses the non-noble metal Co. Compared to Ni, its metal hydrogenation ability is relatively weaker, resulting in a certain degree of reduction in both conversion and selectivity. This indicates that a moderate hydrogenation ability of non-noble metals such as Ni is more conducive to the selectivity control of this tandem reaction.
[0045] 3. Synergistic effect of metal-acid sites. The integrated catalyst of this invention (catalyst 1) performs significantly better than the system of simply physically mixing Ni / SiO2 with modified molecular sieve Al (catalyst 7). This confirms that the close proximity of the metal site and the acid site is the key to achieving efficient tandem catalysis, eliminating the need for long-range diffusion of reaction intermediates in solution and avoiding homogeneous side reactions.
[0046] 3. Universality of the modification method. Whether through hydrothermal dealumination (catalysts 1, 2) or chemical silanization (catalyst 3), as long as the acidity of the molecular sieve can be controlled within the preferred range of this invention, excellent catalytic performance can be obtained, proving the universality and reliability of the technical route of this invention.
[0047] Catalyst stability test The catalyst 1 used in the above examples was recovered, washed, dried, and calcined after the reaction, and then regenerated at 400°C for 1 hour under H2 atmosphere before being directly used in the next round of reaction. After five consecutive cycles, the HMF conversion rate remained above 95%, and the HCPN selectivity remained above 90%. Figure 2 As shown, this indicates that the catalyst has good stability and reusability.
[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A metal-molecular sieve bifunctional catalyst for the preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural, characterized in that, The catalyst is composed of an active metal component and a molecular sieve support; The active metal component is at least one of Ni, Co, and Cu; The molecular sieve support is an MFI, BEA, or MOR structured molecular sieve modified by hydrothermal dealumination or chemical silanization, with a molar ratio of Brønsted acid to Lewis acid of 0.1 to 1.5 and a total acid content of 0.1 to 0.8 mmol / g.
2. The metal-molecular sieve bifunctional catalyst for the preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural according to claim 1, characterized in that, Based on the total mass of the catalyst, the loading of the active metal component is 0.5 wt.% to 15 wt.%; the MFI, BEA or MOR structured molecular sieve is at least one of HZSM-5 and HBeta.
3. The metal-molecular sieve bifunctional catalyst for the preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural according to claim 2, characterized in that, The molecular sieve support has a silicon-to-aluminum ratio, i.e., a molar ratio of SiO2 / Al2O3 of 20 to 150; a molar ratio of Brønsted acid to Lewis acid of 0.1 to 0.8; and a total acid content of 0.1 to 0.5 mmol / g.
4. A method for preparing a metal-molecular sieve bifunctional catalyst for the preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural according to any one of claims 1 to 3, characterized in that, Includes the following steps: (1) Modification of molecular sieve support: The original molecular sieve is subjected to hydrothermal dealumination or chemical silanization to obtain a modified molecular sieve support with a specific B / L acid ratio. (2) Metal loading: The solution containing the active metal precursor is added dropwise to the modified molecular sieve support obtained in step (1), and loading is carried out by the equal volume impregnation method; (3) Calcination and reduction: The sample obtained in step (2) is dried and then calcined in an air atmosphere, and then reduced in a reducing atmosphere to obtain the bifunctional catalyst.
5. The preparation method according to claim 4, characterized in that, In step (1), The hydrothermal dealuminization process involves treating the molecular sieve in a steam atmosphere at 500-700℃ for 1-10 hours to obtain a modified molecular sieve carrier. Alternatively, the molecular sieve is treated in a steam atmosphere at 500-700℃ for 1-10 hours, then acid-washed to remove some of the non-framework aluminum, and dried to obtain the modified molecular sieve support. The chemical silanization process involves mixing a molecular sieve with a silanizing agent, refluxing the reaction, filtering, washing, and drying to obtain a modified molecular sieve support.
6. The preparation method according to claim 5, characterized in that, In step (1), during the hydrothermal dealuminization process, the pickling is performed using 0.1~0.5M hydrochloric acid at 50~100℃ for 1~5 hours; In the chemical silanization process, the silanizing agent is a 0.1-1M hexamethyldisilazane-hexane solution, and the reflux reaction conditions are 30-80°C for 3-10 hours.
7. The preparation method according to claim 4, characterized in that, In step (2), the solution containing the active metal precursor is at least one of the corresponding metal nitrate aqueous solution, acetate aqueous solution, and chloride aqueous solution; after the addition is completed, it is left to stand at room temperature for 10 to 24 hours.
8. The preparation method according to claim 4, characterized in that, In step (3), the calcination temperature is 300-600℃ and the calcination time is 1-6 hours; the reducing atmosphere is hydrogen, the reduction temperature is 300-500℃ and the time is 2-6 hours.
9. The use of the bifunctional catalyst according to any one of claims 1 to 3 in the catalytic preparation of 3-hydroxymethylcyclopentanone from 5-hydroxymethylfurfural.
10. The application according to claim 9, characterized in that, The bifunctional catalyst was added to a 5-hydroxymethylfurfural solution. After purging the air from the reaction environment, hydrogen gas was introduced to an initial pressure of 1.0–2.0 MPa. The mixture was then stirred at 1000–5000 rpm and heated to 100–180 °C for 3–6 hours. The amount of the bifunctional catalyst added was 20–60 wt% of the 5-hydroxymethylfurfural. It also includes a method for recovering the catalyst: the catalyst after the reaction is recovered, washed, dried and calcined, and then regenerated at 300~500℃ for 1~5 hours in H2 atmosphere before being used directly in the next round of reaction.