Zirconium metal-organic framework supported platinum nanocatalysts, their preparation methods and applications

Abstract

This application provides a zirconium metal-organic framework-supported platinum nanoparticle catalyst, its preparation method, and its application, belonging to the technical field of catalysts for the selective hydrogenation of furfural to furfuryl alcohol. The process includes the following steps: dispersing platinum nanoparticles in a first solvent to obtain a first mixture; mixing bisimidazole tetracarboxylic acid with a zirconium salt, adding a second solvent and an acid regulator, and mixing thoroughly to obtain a second mixture; adding the first mixture to the second mixture, and reacting under heating conditions to obtain the zirconium metal-organic framework-supported platinum nanoparticle catalyst. This application uses the zirconium metal-organic framework Zr-BBI as a support, encapsulating platinum nanoparticles within the pores of the framework. In the Zr-BBI linker, the uncoordinated nitrogen atoms of the bisimidazole group can better anchor and stabilize the guest platinum, enhancing the interaction between the platinum and the host. The strong interaction between platinum and Zr-BBI promotes high dispersion of the platinum nanoparticles, resulting in Zr-BBI-supported platinum nanoparticles with uniform and small particle sizes.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology for the selective hydrogenation of furfural to prepare furfuryl alcohol, specifically to zirconium metal-organic framework supported platinum nanocatalysts, their preparation methods, and applications. Background Technology

[0002] Lignocellulose-derived furfural is an important biomass platform molecule widely used as an intermediate product, providing a variety of products for the energy sector, as well as the chemical and pharmaceutical industries. As an α,β-unsaturated aldehyde, furfural contains both an aldehyde C=O group and a furan ring C=C group, both unsaturated groups. Selective hydrogenation is a major route for the efficient conversion of furfural into high-value-added chemicals such as furfuryl alcohol, tetrahydrofurfuryl alcohol, furans, 2-methylfuran, and cyclopentanone. Among these, furfuryl alcohol is considered a key renewable chemical intermediate, widely used in the manufacture of crown ethers, adhesives, furan-based resins, synthetic fibers, fuels, and additives. Due to the diversity of unsaturated groups, the selective hydrogenation of biomass furfural to produce furfuryl alcohol is challenging.

[0003] While noble metal catalysts such as Pt, Pd, and Ru exhibit excellent hydrogenation performance, they can also lead to deep hydrogenation of C=C in the furan ring, resulting in low selectivity for furfuryl alcohol. Metal-organic frameworks (MOFs), as heterogeneous catalysts, have attracted increasing attention due to their well-defined active sites, high porosity, tunable pore size, and rich pore structure. Utilizing MOFs to encapsulate platinum nanoparticles can effectively regulate the hydrogenation selectivity of platinum nanoparticle catalysts, suppressing the flattening adsorption and activation of the furan ring to some extent, thereby increasing the hydrogenation selectivity of aldehyde groups. Although existing supported catalytic materials have achieved high furfuryl alcohol yields, most catalytic systems typically require relatively harsh reaction conditions, such as high reaction temperatures (180–210 °C) and high hydrogen pressures (4–8 MPa), leading to high energy consumption, high costs, and stringent operating conditions, limiting their practical applications. Therefore, developing novel supported catalytic materials to achieve a simple and efficient synthesis of furfuryl alcohol via furfural hydrogenation under mild conditions remains of great significance.

[0004] Significant progress has been made in preparing supported catalysts by encapsulating platinum nanoparticles in metal-organic frameworks (MOFs), which have demonstrated excellent catalytic performance in many biomass conversion studies. However, these platinum atoms are typically located on the outer surface of MOFs and tend to aggregate. Furthermore, although some platinum nanoparticles are encapsulated in the pores of MOFs, these metal atoms may leach out from the MOF framework due to the lack of interaction with it. Summary of the Invention

[0005] In view of the technical problems existing in the background art, this application provides zirconium metal-organic framework supported nano-platinum catalyst, its preparation method and application, aiming to solve the technical problems of harsh conditions and catalyst instability in the selective hydrogenation synthesis of furfural.

[0006] In a first aspect, embodiments of this application provide a method for preparing a zirconium metal-organic framework supported platinum nanocatalyst, comprising the following steps:

[0007] Platinum nanoparticles are dispersed in a first solvent to obtain a first mixture;

[0008] Diimidazole tetracarboxylic acid and zirconium salt were mixed, and then a second solvent and an acid regulator were added and mixed evenly to obtain a second mixture.

[0009] The first mixture was added to the second mixture, and after reaction under heating conditions, zirconium metal-organic framework supported platinum nanocatalyst was obtained.

[0010] Preferably, the heating temperature is 115~130℃ and the heating time is 48~72h.

[0011] Preferably, the preparation method of platinum nanoparticles includes the following steps: dispersing PVP in ethylene glycol, adding H2PtCl6, ultrasonically dispersing and heating to obtain a third mixture, adding acetone to the third mixture for precipitation, centrifuging to collect the solid, vacuum drying the solid and washing it with acetone to obtain platinum nanoparticles.

[0012] Preferably, the concentration of platinum nanoparticles in the first mixture is 1~2 mg / mL.

[0013] Preferably, the first solvent is DMF (anhydrous N,N-dimethylformamide).

[0014] Preferably, the diimidazolium tetracarboxylic acid is H4BBI (1,4-phenylbis(1H-imidazol-2,4,5-triyl)tetrabenzoic acid), and the zirconium salt is ZrCl4. In the second mixture, H4BBI and Zr... 4+ The molar ratio is 1:(1~2).

[0015] Preferably, the volume ratio of the second solvent to the acid regulator is 5:(1~3); the second solvent is DMF, and the acid regulator is formic acid.

[0016] Secondly, embodiments of this application provide a zirconium metal-organic framework supported platinum nanoparticle catalyst, which is prepared by the above-described method for preparing zirconium metal-organic framework supported platinum nanoparticle catalyst.

[0017] Thirdly, embodiments of this application provide an application of a zirconium metal-organic framework supported platinum nanocatalyst in the preparation of furfuryl alcohol, comprising the following steps:

[0018] S1. The zirconium metal-organic framework supported platinum nano-catalyst was reduced by heating in a reducing gas atmosphere, and the reduced zirconium metal-organic framework supported platinum nano-catalyst was obtained after cooling.

[0019] S2. Mix furfural and the third solvent, then add the reduced zirconium metal-organic framework supported platinum nano-catalyst. Add 20-40 mg of the reduced zirconium metal-organic framework supported platinum nano-catalyst to each millimole of furfural. React under a hydrogen atmosphere. The reaction conditions are: pressure 1-2 MPa, temperature 80-120℃, and reaction time 6-24 h. After the reaction is completed, cool and centrifuge to separate the reduced zirconium metal-organic framework supported platinum nano-catalyst to obtain furfuryl alcohol.

[0020] Preferably, the reducing gas in step S1 includes nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen is 1:(1~20).

[0021] The advantages of this application, which differ from existing technical solutions, include:

[0022] 1. This application uses H4BBI and ZrCl4 as raw materials to prepare a zirconium metal-organic framework (Zr-BBI). Platinum nanoparticles are encapsulated within the pores of the Zr-BBI framework using Zr-BBI as a carrier. In the Zr-BBI linker, the uncoordinated nitrogen atoms of the bisimidazole groups can better anchor and stabilize the guest platinum, enhancing the interaction between the platinum and the host. The strong interaction between platinum and Zr-BBI promotes high dispersion of the platinum nanoparticles, resulting in Zr-BBI-loaded platinum nanoparticles with uniform and small particle sizes.

[0023] 2. The zirconium metal-organic framework supported platinum nanocatalyst (Pt@Zr-BBI) prepared in this application has high catalytic activity and selectivity. It can achieve selective hydrogenation of furfural to furfuryl alcohol under mild conditions. Using isopropanol as solvent, the conversion rate of furfural can reach 100% after reaction at 120℃ for 12h, and the selectivity of furfuryl alcohol can reach 94.5%.

[0024] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0026] Figure 1 XRD patterns of zirconium metal-organic framework and zirconium metal-organic framework-supported platinum nanoparticle catalyst prepared in Example 1;

[0027] Figure 2 This is a SEM image of the zirconium metal-organic framework supported platinum nanoparticle catalyst prepared in Example 1;

[0028] Figure 3 This is a TEM image of the zirconium metal-organic framework supported platinum nanoparticle catalyst prepared in Example 1. Detailed Implementation

[0029] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0031] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0032] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0034] Although existing supported catalytic materials have achieved high furfuryl alcohol yields, most catalytic systems typically require relatively harsh reaction conditions, such as high reaction temperatures (180–210 °C) and high hydrogen pressures (4–8 MPa). This results in high energy consumption, high costs, and stringent operating conditions, limiting their practical applications. Therefore, developing novel supported catalytic materials to achieve a simple and efficient synthesis of furfuryl alcohol via furfural hydrogenation under mild conditions remains of great significance.

[0035] Significant progress has been made in preparing supported catalysts by encapsulating platinum nanoparticles in metal-organic frameworks (MOFs), which have demonstrated excellent catalytic performance in many biomass conversion studies. However, these platinum atoms are typically located on the outer surface of MOFs and tend to aggregate. Furthermore, although some platinum nanoparticles are encapsulated in the pores of MOFs, these metal atoms may leach out from the MOF framework due to the lack of interaction with it.

[0036] To address the challenges of demanding conditions and catalyst instability in the selective hydrogenation of furfural to furfuryl alcohol, this application provides a zirconium metal-organic framework-supported platinum nanoparticle catalyst, its preparation method, and its applications. Specifically, this application uses H4BBI and ZrCl4 as raw materials to prepare a zirconium metal-organic framework (Zr-BBI). Platinum nanoparticles are encapsulated within the pores of the Zr-BBI support. In the Zr-BBI linker, the uncoordinated nitrogen atoms of the imidazolium group can better anchor and stabilize the guest platinum, enhancing the interaction between the platinum and the host. The strong interaction between platinum and Zr-BBI promotes high dispersion of the platinum nanoparticles, resulting in Zr-BBI-supported platinum nanoparticles with uniform and small particle sizes.

[0037] In a first aspect, embodiments of this application provide a method for preparing a zirconium metal-organic framework supported platinum nanocatalyst, comprising the following steps:

[0038] Platinum nanoparticles are dispersed in a first solvent to obtain a first mixture;

[0039] Diimidazole tetracarboxylic acid and zirconium salt were mixed, and then a second solvent and an acid regulator were added and mixed evenly to obtain a second mixture.

[0040] The first mixture was added to the second mixture, and after reaction under heating conditions, zirconium metal-organic framework supported platinum nanocatalyst was obtained.

[0041] Preferably, the heating temperature is 115~130℃ and the heating time is 48~72h.

[0042] Preferably, the preparation method of platinum nanoparticles includes the following steps: dispersing PVP in ethylene glycol, adding H2PtCl6, ultrasonically dispersing and heating to obtain a third mixture, adding acetone to the third mixture for precipitation, centrifuging to collect the solid, vacuum drying the solid and washing it with acetone to obtain platinum nanoparticles.

[0043] Preferably, the concentration of platinum nanoparticles in the first mixture is 1~2 mg / mL.

[0044] Preferably, the first solvent is DMF.

[0045] Preferably, the diimidazole tetracarboxylic acid is H4BBI, and the zirconium salt is ZrCl4. In the second mixture, H4BBI and Zr... 4+ The molar ratio is 1:(1~2).

[0046] Preferably, the volume ratio of the second solvent to the acid regulator is 5:(1~3); the second solvent is DMF, and the acid regulator is formic acid.

[0047] In the technical solution of this application embodiment, H4BBI and ZrCl4 are used as raw materials, DMF is used as solvent, and formic acid is used as an acid regulator to successfully synthesize a zirconium metal-organic framework Zr-BBI. Zr-BBI is used as a carrier to encapsulate platinum nanoparticles within the pores of the framework. In the Zr-BBI linker, the uncoordinated nitrogen atoms of the bisimidazole group can better anchor and stabilize the guest platinum, enhancing the interaction between the platinum and the host.

[0048] Secondly, embodiments of this application provide a zirconium metal-organic framework supported platinum nanoparticle catalyst, which is prepared by the above-described method for preparing zirconium metal-organic framework supported platinum nanoparticle catalyst.

[0049] Thirdly, embodiments of this application provide an application of a zirconium metal-organic framework supported platinum nanocatalyst in the preparation of furfuryl alcohol, comprising the following steps:

[0050] S1. The zirconium metal-organic framework supported platinum nano-catalyst was reduced by heating in a reducing gas atmosphere, and the reduced zirconium metal-organic framework supported platinum nano-catalyst was obtained after cooling.

[0051] S2. Mix furfural and a third solvent, which is isopropanol, and then add the reduced zirconium metal-organic framework supported platinum nano-catalyst. Add 20-40 mg of the reduced zirconium metal-organic framework supported platinum nano-catalyst to each millimole of furfural. React under a hydrogen atmosphere. The reaction conditions are: pressure 1-2 MPa, temperature 80-120℃, and reaction time 6-24 h. After the reaction is completed, cool and centrifuge to separate the reduced zirconium metal-organic framework supported platinum nano-catalyst to obtain furfuryl alcohol.

[0052] Preferably, the reducing gas in step S1 includes nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen is 1:(1~20).

[0053] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0054] I. Preparation Method

[0055] Example 1

[0056] (1) Preparation of platinum nanoparticles: 444 mg PVP was dissolved in 20 mL of ethylene glycol, and then 101.5 mg H2PtCl6 was added. The solution was sonicated to dissolve completely. The mixture was heated at 180 °C for 10 min, then precipitated with acetone and collected by centrifugation at 8000 rpm for 5 min. The collected solid was dried overnight at 60 °C in a vacuum drying oven. The dried solid was washed three times with acetone to remove excess free PVP. The obtained platinum nanoparticles (Pt NPs) were then dispersed in a certain volume of anhydrous N,N-dimethylformamide (DMF) solvent (concentration 2 mg / mL) for storage.

[0057] (2) Preparation of zirconium metal-organic framework supported platinum nanoparticle catalyst (Pt@Zr-BBI): 14 mg of the organic ligand 1,4-phenylbis(1H-imidazolium-2,4,5-triyl)tetrabenzoic acid (H4BBI) and 24 mg of zirconium tetrachloride were mixed in a 20 mL glass bottle. Then, 5 mL of anhydrous N,N-dimethylformamide (DMF) and 1.5 mL of formic acid were added. After thorough mixing, 0.5 mL of Pt NPs (concentration 2 mg / mL) from step (1) was added. The glass bottle was placed in an oven at 120 °C and heated at a constant temperature for 72 h. After cooling to room temperature, the solid was collected, washed with DMF, and dried to obtain the zirconium metal-organic framework supported platinum nanoparticle catalyst (Pt@Zr-BBI).

[0058] (3) Pretreatment of catalyst: The dried sample was placed in a tube furnace and heated to 120°C at a rate of 10°C / min under nitrogen protection. Then it was reduced for 1 h in a hydrogen / nitrogen (50% v:v) atmosphere. After that, it was cooled to room temperature, taken out and placed in a vacuum drying oven to obtain the reduced zirconium metal-organic framework supported platinum nanoparticle catalyst (Pt@Zr-BBI).

[0059] (4) Reactions for the preparation of furfural alcohol by catalytic hydrogenation: 1 mmol furfural, 1 mmol dodecane and 10 mL isopropanol were placed in a batch reactor, with dodecane as an internal standard. Then, 20 mg of reduced zirconium metal-organic framework supported platinum nanoparticle catalyst (Pt@Zr-BBI) was added to the above liquid. After sealing the batch reactor, 1.5 MPa of hydrogen gas was introduced into it. Then, the temperature was raised under stirring at 600 rpm. After reaching the reaction temperature of 80 °C, the reaction started. After reacting for 24 h, the reaction was cooled to room temperature. After centrifugation, the reduced zirconium metal-organic framework supported platinum nanoparticle catalyst was separated to obtain furfural alcohol.

[0060] Example 2

[0061] The difference between Example 2 and Example 1 is that the reaction temperature used in the catalytic hydrogenation of furfural to prepare furfuryl alcohol is 100°C, while the other steps are the same as in Example 1.

[0062] Example 3

[0063] The difference between Example 3 and Example 1 is that the reaction temperature used in the catalytic hydrogenation of furfural to prepare furfuryl alcohol is 120°C, while the other steps are the same as in Example 1.

[0064] Example 4

[0065] The difference between Example 4 and Example 3 is that the reaction time used in the catalytic hydrogenation of furfural to prepare furfuryl alcohol is 6 hours, while the other steps are the same as in Example 3.

[0066] Example 5

[0067] The difference between Example 5 and Example 3 is that the reaction time used in the catalytic hydrogenation of furfural to prepare furfuryl alcohol is 9 hours, while the other steps are the same as in Example 3.

[0068] Example 6

[0069] The difference between Example 6 and Example 3 is that the reaction time used in the catalytic hydrogenation of furfural to prepare furfuryl alcohol is 12 hours, while the other steps are the same as in Example 3.

[0070] Example 7

[0071] The difference between Example 7 and Example 3 is that the reaction time used in the catalytic hydrogenation of furfural to prepare furfuryl alcohol is 15 hours, while the other steps are the same as in Example 3.

[0072] Example 8

[0073] The difference between Example 8 and Example 6 is that 30 mg of zirconium metal-organic framework supported platinum nanoparticle catalyst (Pt@Zr-BBI) was added in the reaction of furfural catalytic hydrogenation to prepare furfuryl alcohol. All other steps are the same as in Example 6.

[0074] Example 9

[0075] The difference between Example 9 and Example 6 is that 40 mg of zirconium metal-organic framework supported platinum nanoparticle catalyst (Pt@Zr-BBI) was added in the reaction of furfural catalytic hydrogenation to prepare furfuryl alcohol. All other steps are the same as in Example 6.

[0076] Comparative Example 1

[0077] In Comparative Example 1, platinum nanoparticles were used to catalytically hydrogenate furfural. The specific steps are as follows:

[0078] (1) Preparation of platinum nanoparticles: 444 mg PVP was dissolved in 20 mL of ethylene glycol, and then 101.5 mg H2PtCl6 was added. The solution was sonicated to dissolve completely. The mixture was heated at 180 °C for 10 min, then precipitated with acetone and collected by centrifugation at 8000 rpm for 5 min. The collected solid was dried overnight at 60 °C in a vacuum drying oven. The dried solid was washed three times with acetone to remove excess free PVP. The obtained platinum nanoparticles (Pt NPs) were then dispersed in a certain volume of anhydrous N,N-dimethylformamide (DMF) solvent (concentration 2 mg / mL) for storage.

[0079] (2) The reaction of furfural catalytic hydrogenation to prepare furfuryl alcohol: 1 mmol of furfural, 1 mmol of dodecane and 10 mL of isopropanol were placed in a batch reactor, and 1 mg of platinum nanoparticle (Pt NPs) catalyst was added to the above liquid. After sealing the batch reactor, hydrogen gas at 1.5 MPa was introduced into it, and then the temperature was raised to 120 °C under stirring at 600 rpm for 12 h. After the reaction was completed, the mixture was cooled to room temperature, and the reduced zirconium metal-organic framework supported platinum nanocatalyst was separated by centrifugation to obtain furfuryl alcohol.

[0080] Comparative Example 2

[0081] In Comparative Example 2, platinum nanoparticles supported on UiO-66 were used for the catalytic hydrogenation of furfural. The specific steps are as follows:

[0082] (1) Preparation of platinum nanoparticles: 444 mg PVP was dissolved in 20 mL of ethylene glycol, and then 101.5 mg H2PtCl6 was added. The solution was sonicated to dissolve completely. The mixture was heated at 180 °C for 10 min, then precipitated with acetone and collected by centrifugation at 8000 rpm for 5 min. The collected solid was dried overnight at 60 °C in a vacuum drying oven. The dried solid was washed three times with acetone to remove excess free PVP. The obtained platinum nanoparticles (Pt NPs) were then dispersed in a certain volume of anhydrous N,N-dimethylformamide (DMF) solvent (concentration 2 mg / mL) for storage.

[0083] (2) Preparation of UiO-66 supported platinum nanoparticle catalyst (Pt@UiO-66): 16.6 mg of organic ligand terephthalic acid (H2BDC) and 23.3 mg of zirconium tetrachloride were mixed in a 20 mL glass bottle, then 10 mL of N,N-dimethylformamide (DMF) and 1.37 mL of acetic acid were added. After thorough mixing, 0.5 mL of Pt NPs (concentration 2 mg / mL) from step (1) was added. The glass bottle was placed in an oven at 120 °C and heated at a constant temperature for 24-48 h. After cooling to room temperature, the solid was collected, washed with DMF, and dried to obtain Pt@UiO-66.

[0084] (3) Pretreatment of catalyst: The dried sample was placed in a tube furnace and heated from room temperature to 120°C at a rate of 10°C / min under nitrogen protection. Then it was reduced for 1 hour in a hydrogen / nitrogen (50% v:v) atmosphere. After that, it was cooled to room temperature, taken out and placed in a vacuum drying oven to obtain the reduced Pt@UiO-66.

[0085] (4) Reactions for the preparation of furfural alcohol by catalytic hydrogenation: 1 mmol furfural, 1 mmol dodecane and 10 mL isopropanol were placed in a batch reactor, with dodecane as an internal standard. Then, 30 mg of reduced Pt@UiO-66 was added to the above liquid. After sealing the batch reactor, 1.5 MPa of hydrogen gas was introduced into it. The reactor was then heated under stirring at 600 rpm until the reaction temperature reached 120 °C. After reacting for 12 h, the reactor was cooled to room temperature. The reduced Pt@UiO-66 catalyst was separated by centrifugation to obtain furfural alcohol.

[0086] II. Testing Methods

[0087] 1. Detection methods for X-ray powder diffraction (XRD), SEM, TEM, and EDS.

[0088] The X-ray powder diffraction (XRD) applied for used a Rigaku Ultimate IV diffractometer with a Cu-Kα target (40 kV, 40 mA) to analyze the structure and purity of the materials. The test range was 3–50°, and the scan rate was 10° / min.

[0089] This application uses a TESCAN MIRA LMS cold field emission scanning electron microscope (SEM) to observe the microstructure and size of the material.

[0090] Transmission electron microscopy (TEM) images, high-resolution transmission electron microscopy (TEM) images, and elemental distributions (EDS) were obtained using a multifunctional field emission scanning electron microscope (TEM) (model Thermo Fisher Talos F200s).

[0091] 2. Detection methods for furfural conversion rate, furfuryl alcohol selectivity, and furfuryl alcohol yield

[0092] The composition of the catalytic hydrogenation liquid product obtained in the embodiments of this application was analyzed by GC-9790II gas chromatography with FID detector, and the reaction results were calculated.

[0093] III. Analysis of Test Results for Each Embodiment and Comparative Example

[0094] (1) The structure of the zirconium metal-organic framework supported platinum nanoparticle catalyst (Pt@Zr-BBI) synthesized in Example 1 was characterized by X-ray powder diffraction (XRD), such as... Figure 1 As shown, the XRD patterns of zirconium metal-organic frameworks (Zr-BBI) and Pt@Zr-BBI are consistent with the patterns simulated using single-crystal X-ray diffraction data, indicating that the original MOF framework was not destroyed, demonstrating that the structure of the material remains unaffected after loading platinum nanoparticles onto the zirconium metal-organic framework. The diffraction characteristic peaks of platinum nanoparticles in the XRD pattern of Pt@Zr-BBI are not obvious. This may be due to the low concentration of platinum nanoparticles encapsulated in Zr-BBI and the material itself, or it may be due to the small size of the platinum nanoparticles, making their characteristic diffraction peaks undetectable or identifiable.

[0095] The morphology and size of the zirconium metal-organic framework-supported platinum nanoparticle catalyst (Pt@Zr-BBI) were characterized by SEM and TEM. Compared with Zr-BBI, the supported Pt@Zr-BBI maintained its rod-like morphology well. Figure 2 TEM analysis showed that platinum nanoparticles were uniformly dispersed in Zr-BBI with an average size of approximately 4.1 nm, while EDS further confirmed the uniform distribution of platinum in the material. Figure 3 ).

[0096] (2) In Examples 1 to 3, the reaction temperatures for the catalytic hydrogenation of furfural to prepare furfuryl alcohol were 80℃, 100℃ and 120℃, respectively. The furfural conversion and furfuryl alcohol selectivity in Examples 1 to 3 were detected, and the results are shown in Table 1 below.

[0097] Table 1. Effect of reaction temperature on furfural conversion and furfuryl alcohol selectivity

[0098]

[0099] As shown in Table 1, the conversion rate of furfural increases and the reaction rate accelerates with increasing reaction temperature. The optimal reaction temperature for preparing furfural alcohol is 120℃.

[0100] (3) In Examples 3 to 7, the reaction times for the catalytic hydrogenation of furfural to prepare furfuryl alcohol were 24h, 6h, 9h, 12h and 15h, respectively. The furfural conversion and furfuryl alcohol selectivity in Examples 3 to 7 were detected, and the detection results are shown in Table 2 below.

[0101] Table 2 Effect of reaction time on furfural conversion and furfuryl alcohol selectivity

[0102]

[0103] Table 2 shows that the conversion rate of furfural increases with increasing reaction time, and the selectivity for converting furfural to furfuryl alcohol is highest when the reaction proceeds for 12 hours. However, the selectivity for furfuryl alcohol decreases with further increases in reaction time. Therefore, the optimal reaction time is 12 hours.

[0104] (4) In Examples 6 and 8-9, the zirconium metal-organic framework supported platinum nanoparticle catalyst (Pt@Zr-BBI) added to the reaction of furfural catalytic hydrogenation to prepare furfuryl alcohol was 20 mg, 30 mg and 40 mg respectively. The furfural conversion and furfuryl alcohol selectivity in Examples 6 and 8-9 were detected respectively, and the detection results are shown in Table 3 below.

[0105] Table 3 Effect of catalyst dosage on furfural conversion and furfuryl alcohol selectivity

[0106]

[0107] As can be seen from Table 3, the highest furfural conversion rate and furfuryl alcohol yield were achieved when the catalyst dosage was 30 mg.

[0108] (5) In Comparative Example 1 and Comparative Example 2, furfural was catalytically hydrogenated using platinum nanoparticles (Pt NPs) and UiO-66 supported platinum nanoparticle catalyst (Pt@UiO-66), respectively. The furfural conversion and furfuryl alcohol selectivity in Comparative Example 1, Comparative Example 2 and Example 8 were detected, and the results are shown in Table 4 below.

[0109] Table 4. Effects of NPs and Pt@Zr-BBI on furfural conversion and furfuryl alcohol selectivity

[0110]

[0111] Table 4 shows that compared to platinum nanoparticles (Pt NPs) and the Pt@UiO-66 catalyst alone, the zirconium metal-organic framework-supported platinum nanoparticle catalyst (Pt@Zr-BBI) significantly improves its catalytic activity and selectivity. This indicates that the strong interaction between platinum and Zr-BBI promotes the high dispersion of platinum nanoparticles, resulting in Zr-BBI-supported platinum nanoparticles with uniform and small particle size. Furthermore, experiments revealed that using other metals to replace zirconium cannot synthesize isomorphic metal-organic frameworks with H4BBI.

[0112] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. The application of a zirconium metal-organic framework supported platinum nanocatalyst in the preparation of furfuryl alcohol, characterized in that, Includes the following steps: Platinum nanoparticles are dispersed in a first solvent to obtain a first mixture; Diimidazole tetracarboxylic acid and zirconium salt were mixed, and then a second solvent and an acid regulator were added and mixed evenly to obtain a second mixture. The first mixture was added to the second mixture, and after reaction under heating conditions, zirconium metal-organic framework supported platinum nanocatalyst was obtained; The zirconium metal-organic framework supported platinum nanocatalyst was reduced by heating in a reducing gas atmosphere, and the reduced zirconium metal-organic framework supported platinum nanocatalyst was obtained after cooling. Furfural and a third solvent were mixed, and then the reduced zirconium metal-organic framework supported nano-platinum catalyst was added. 20-40 mg of the reduced zirconium metal-organic framework supported nano-platinum catalyst was added to each millimole of furfural. The reaction was carried out under a hydrogen atmosphere. The reaction conditions were: pressure 1-2 MPa, temperature 80-120℃, and reaction time 6-24 h. After the reaction was completed, the mixture was cooled, and the reduced zirconium metal-organic framework supported nano-platinum catalyst was separated by centrifugation to obtain furfuryl alcohol. The bisimidazole tetracarboxylic acid is H4BBI, and the zirconium salt is ZrCl4. In the second mixture, H4BBI and Zr... 4+ The molar ratio is 1:(1~2).

2. The application of the zirconium metal-organic framework supported platinum nanocatalyst according to claim 1 in the preparation of furfuryl alcohol, characterized in that, The heating temperature is 115~130℃, and the heating time is 48~72h.

3. The application of the zirconium metal-organic framework supported platinum nanocatalyst according to claim 1 in the preparation of furfuryl alcohol, characterized in that, The preparation method of the platinum nanoparticles includes the following steps: dispersing PVP in ethylene glycol, adding H2PtCl6, ultrasonically dispersing and heating to obtain a third mixture, adding acetone to the third mixture for precipitation, centrifuging to collect the solid, vacuum drying the solid and washing it with acetone to obtain platinum nanoparticles.

4. The application of the zirconium metal-organic framework supported platinum nanocatalyst according to claim 1 in the preparation of furfuryl alcohol, characterized in that, The concentration of platinum nanoparticles in the first mixture is 1~2 mg / mL.

5. The application of the zirconium metal-organic framework supported platinum nanocatalyst according to claim 1 in the preparation of furfuryl alcohol, characterized in that, The first solvent is DMF.

6. The application of the zirconium metal-organic framework supported platinum nanocatalyst according to claim 1 in the preparation of furfuryl alcohol, characterized in that, The volume ratio of the second solvent to the acid regulator is 5:(1~3); the second solvent is DMF, and the acid regulator is formic acid.

7. The application of the zirconium metal-organic framework supported platinum nanocatalyst according to claim 1 in the preparation of furfuryl alcohol, characterized in that, The reducing gas in step S1 includes nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen is 1:(1~20).

Images