Preparation method and application of difunctional rodlike CeO2ZSM-5 composite catalyst

Abstract

The invention relates to a difunctional rod-shaped CeO2amp; the preparation method of the ZSM-5 composite catalyst specifically comprises the following steps: weighing cerium nitrate hexahydrate and sodium hydroxide, dissolving the cerium nitrate hexahydrate and the sodium hydroxide in deionized water to obtain a light blue solution, and standing; after standing, adding acidic ZSM-5 while stirring to form a white turbid solution, and reacting for a period of time; after the reaction is finished, transferring the white turbid solution into a reaction kettle, carrying out hydrothermal reaction to obtain a blue precipitate, washing the blue precipitate with deionized water and absolute ethyl alcohol respectively, and drying to obtain a rod-like precursor; carrying out high-temperature calcination on the precursor in an air atmosphere to obtain difunctional rod-like CeO2amp with uniform oxygen vacancies and acidity; the invention discloses a ZSM-5 composite catalyst. The catalyst is applied to catalytic conversion of lignin oil and oligomers thereof. The method is simple in preparation process, low in cost, stable in structure and high in active center dispersity, overcomes weak interaction between carriers, and has an efficient catalytic conversion effect on lignin oil and derived oligomers thereof.

Description

Technical field:

[0001] The invention belongs to the field of catalysts, and in particular relates to a preparation method and application of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst. Background technology:

[0002] Energy sources such as petroleum cannot be regenerated in a short period of time, and their consumption rate far exceeds their regeneration rate. As a clean energy source with large reserves and renewable energy, biomass energy has received more and more attention. In wood fiber, lignin accounts for about 40% of the total energy. It is a macromolecular compound composed of structural units such as lignin-derived C7 oligomers. It is the only renewable resource containing aromatic rings in nature. At present, catalytic degradation of lignin can obtain bio-oil products mainly composed of lignin-derived oligomers. Therefore, research on high value-added conversion of lignin-derived oligomers is of great significance.

[0003] The catalysts commonly used in the hydrodeoxygenation reaction of lignin-derived oligomers are mainly divided into catalysts with noble metals as catalytic active components and catalysts with non-noble metals as catalytic active components. However, noble metal catalysts have been difficult to be applied in large-scale industry due to their high cost and low reserves. Non-noble metal catalysts have weak interaction between metal and carrier, which leads to poor stability, and nanoparticles are prone to agglomeration, sintering and loss, thereby reducing the effective use of metal active components.

[0004] Therefore, there is an urgent need to design a catalyst that is low-cost, stable in performance and can efficiently catalyze the conversion of lignin-derived oligomers. Summary of the invention:

[0005] In view of this, the present invention designs a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst and uses it for the catalytic conversion of lignin oil and its oligomers. It has low processing cost and good stability, and can overcome the low dispersion of the catalyst active center and the weak interaction between the carriers.

[0006] A method for preparing a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst, the method comprising the following steps:

[0007] Weigh cerium nitrate hexahydrate and sodium hydroxide, dissolve in deionized water to obtain a light blue solution, and let stand;

[0008] After standing, add acidic ZSM-5 molecular sieve while stirring to form a white turbid solution, and react for a period of time;

[0009] After the reaction is completed, the white turbid solution is transferred into a reaction kettle for hydrothermal reaction to obtain a blue precipitate, which is washed with deionized water and anhydrous ethanol respectively and then dried to obtain a rod-shaped precursor;

[0010] The rod-shaped precursor is calcined at high temperature in an air atmosphere to obtain a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst with uniform oxygen vacancies and acidity.

[0011] Preferably, the method is specifically:

[0012] Weigh cerium nitrate hexahydrate and sodium hydroxide solids in a mass ratio of (0.1-0.2) g:(1.1-1.2) g, dissolve in deionized water, wherein the ratio of solid addition amount to deionized water is (0.1-0.2) g:(0.33-0.34) g, and let stand for 20-40 minutes;

[0013] After standing, acidic ZSM-5 is added under stirring at a temperature of 20°C to 50°C and a stirring speed of 400r / min to 600r / min to form a white turbid solution, wherein the mass ratio of cerium nitrate hexahydrate to ZSM-5 molecular sieve is (0.1 to 0.2) g: (0.06 to 0.08) g, and the reaction is carried out for 1h to 3h, wherein acidic ZSM-5 molecular sieves with different silicon-aluminum ratios can be selected to be added, and generally, the silicon-aluminum ratios of the acidic ZSM-5 molecular sieves are ZSM-5 (Si / Al=36), ZSM-5 (Si / Al=45) and ZSM-5 (Si / Al=200);

[0014] After the reaction is completed, the white turbid solution is transferred to a reactor, and reacted in the reactor at 80° C. to 120° C. for 12 h to 36 h to obtain a blue precipitate. The blue precipitate is centrifuged, washed with deionized water and anhydrous ethanol for 2 to 4 times, respectively, and dried at 60° C. to 120° C. for 5 h to 15 h to obtain a rod-shaped precursor;

[0015] The precursor is calcined at 300° C. to 500° C. for 2 to 6 hours in an air atmosphere to obtain a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst with uniform oxygen vacancies and acidity.

[0016] Preferably, the rod-shaped precursor is a light yellow solid.

[0017] The invention discloses an application of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst, wherein the composite catalyst is used for catalytic conversion of lignin oil and its oligomers.

[0018] Preferably, the application specifically includes: dissolving a reaction substrate in a reaction solvent to obtain a reaction solution, and catalytically reacting the reaction solution with hydrogen under anaerobic conditions, wherein the reaction substrate is lignin oil or one of lignin-derived C7 oligomers, and the reaction solvent is water.

[0019] Preferably, the temperature of the catalytic reaction is 220°C to 60°C, the reaction is carried out under stirring, the stirring speed is 700r / min to 100r / min, the hydrogen pressure is 1.5Mpa to 2.5Mpa, and the reaction time is 1.5h to 2.5h.

[0020] Beneficial effects of the present invention: The preparation method of the present invention adopts an in-situ hydrothermal reaction to prepare a rod-shaped precursor, and the dry precursor is calcined at a high temperature in an air atmosphere to obtain an acidic and O V The uniformly dispersed bifunctional CeO2&ZSM-5 composite catalytic material has a simple preparation process and low cost. The composite catalyst is easy to separate from the reaction system when in use and can be recycled for multiple times, saving costs.

[0021] The CeO2 / ZSM-5 composite catalyst prepared by the method for preparing a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst designed by the present invention has a stable structure by introducing a molecular sieve; the introduction of the acidic ZSM-5 reduces the energy barrier of the bond energy, and provides a proton acid center and a Lewis acid center, further improving the interaction between carriers; the ZSM-5 structure has a large specific surface area and a pore structure, can fully contact with the reaction substrate, improves the selectivity of bond breaking, and thus improves the selectivity of the product; at the same time, oxygen vacancies (O V ), O V The formation of ads ) amount, which increases the oxygen-containing groups in the reaction substrate in the lattice oxygen (O latt ), further solving the problems of poor stability of the composite catalyst, low dispersion of active centers, and weak interactions between carriers;

[0022] The CeO2 / ZSM-5 composite catalyst prepared by the present invention is used for catalytic conversion of lignin oil and C7 oligomers derived from lignin. After the reaction is completed, the filtrate is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry and gas chromatograph. The conversion rate of the reaction can reach 99.9%, and the selectivity of the main product benzene reaches 46.1% to 83.5%. The main product benzene has a good application prospect in industry and can be used for efficient catalytic conversion of lignin oil and oligomers derived from lignin. Description of the drawings:

[0023] Attached Figure 1 Attached is a scanning electron microscope (SEM) image of the CeO2 / ZSM-5 composite catalytic material prepared in Example 1. Figure 2 is an X-ray diffraction spectrum (XRD) of the CeO2 / ZSM-5 composite catalytic material prepared in Examples 1 to 3; Specific implementation method:

[0024] In order to make the technical solution of the present invention easier to understand, the technical solution of the present invention is now clearly and completely described in the form of specific embodiments.

[0025] Embodiment 1:

[0026] The preparation method of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst in this embodiment includes the following steps:

[0027] First, weigh 3.47 g of cerium nitrate hexahydrate and 38.4 g of sodium hydroxide, dissolve them in 140 ml of deionized water, and stir thoroughly to dissolve to form a light blue solution. Let it react for 20 minutes. Then, add 2.42 g of acidic ZSM-5 with a silicon-aluminum ratio (Si / Al) of 36 for an in-situ reaction at a temperature of 20°C and a stirring speed of 400 r / min to react for 1 hour.

[0028] After the reaction is completed, the above solution is transferred to a sealed reactor and reacted at 80°C for 12 hours. After the reaction is completed, the temperature is cooled to room temperature. The obtained light blue precipitate is centrifuged, washed twice with deionized water, washed twice with anhydrous ethanol, and dried at 60°C for 5 hours to obtain a light yellow rod-shaped precursor. After the light yellow rod-shaped precursor is ground into a uniform powder, it is placed in a quartz boat and sent to a heating kettle. In an air atmosphere, it is heated at a heating rate of 2°C per minute, and the heating is stopped at 300°C and kept warm for 2 hours. After the calcination is completed, it is cooled to room temperature to obtain a bifunctional CeO2&ZSM-5 composite catalytic material. The mass ratio of CeO2 / ZSM-5 (Si / Al=36) in the composite catalytic material is 3:5.

[0029] from Figure 1 It can be seen from the figure that the CeO2&ZSM-5 composite catalytic material is successfully prepared by the preparation method of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst disclosed in the present invention. It can be seen from the figure that the crystalline structure of the composite catalytic material and the rod-shaped structure with a size of 200-300nm have relatively few clusters and are evenly dispersed with each other. The relatively dispersed rod-shaped structure is conducive to the acidic ZSM-5 and O V distribution, which indicates that the composite catalyst has more defect sites that make the acidity and O V As active centers are evenly dispersed, the interaction between carriers is enhanced.

[0030] In this embodiment, a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst is used as follows:

[0031] The CeO2 / ZSM-5 (Si / Al=36) composite catalytic material prepared in this embodiment is placed in a high-pressure reactor to catalyze the conversion of C7 oligomers derived from lignin. The C7 oligomers derived from lignin are used as reaction substrates, 10ml of water is used as reaction solvent, 0.03g of the composite catalytic material prepared in this embodiment and 0.03g of C7 oligomers derived from lignin are added, and the reactor is filled with hydrogen at room temperature, the reaction pressure of hydrogen is 1.5MPa, the temperature is raised to a reaction temperature of 220°C, the reaction time is 90min, and the stirring speed is 700r / min. After the reaction is completed, it is cooled to room temperature, and the liquid product is taken, and qualitative and quantitative detection is performed using a gas chromatography-mass spectrometer and a gas chromatograph. The analysis results are shown in Table 1.

[0032] Embodiment 2:

[0033] The preparation method of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst in this embodiment includes the following steps:

[0034] First, weigh 3.40g of cerium nitrate hexahydrate and 37.0g of sodium hydroxide and dissolve them in 140ml of deionized water, stir and dissolve them thoroughly, and form a light blue solution to react for 30min. At a temperature of 30℃ and a stirring speed of 500r / min, add 2.40g of acidic ZSM-5 with a silicon-aluminum ratio (Si / Al) of 45 for in-situ reaction for 2h. After the reaction, transfer the above solution to a reactor and seal it, react at 100℃ for 24h, cool it to room temperature after the reaction, centrifuge the obtained light blue precipitate, wash it 3 times with deionized water, wash it 3 times with anhydrous ethanol, and dry it at 80℃ for 10h to obtain a light yellow rod-shaped precursor. After grinding the above light yellow rod-shaped precursor into uniform powder, put it in a quartz boat and send it into a heating kettle. In an air atmosphere, heat it at a heating rate of 3℃ per minute, stop heating at 400℃, and keep it warm for 4h. After calcination, cool it to room temperature to obtain a bifunctional CeO2&ZSM-5 composite catalytic material. The mass ratio of CeO2 / ZSM-5 (Si / Al=45) in the composite catalytic material is 3:5.

[0035] In this embodiment, a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst is used as follows:

[0036] The CeO2 / ZSM-5 (Si / Al=45) composite catalytic material prepared in this embodiment was placed in a high-pressure reactor to catalytically convert the C7 oligomer derived from lignin, with the C7 oligomer derived from lignin as the reaction substrate, 10 ml of water as the reaction solvent, 0.03 g of the composite catalytic material prepared in this embodiment and 0.03 g of the C7 oligomer derived from lignin were added, the reactor was filled with hydrogen at room temperature, the reaction pressure of hydrogen was 2 MPa, the temperature was raised to a reaction temperature of 240°C, the reaction time was 120 min, the stirring speed was 800 r / min, after the reaction was completed, the temperature was lowered to room temperature, the liquid product was taken, and qualitative and quantitative detection was performed using a gas chromatography-mass spectrometer and a gas chromatograph. The analysis results are shown in Table 1.

[0037] Embodiment 3:

[0038] The preparation method of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst in this embodiment includes the following steps:

[0039] First, weigh 3.57g of cerium nitrate hexahydrate and 39.4g of sodium hydroxide and dissolve them in 140ml of deionized water, stir and dissolve them thoroughly, and form a light blue solution to react for 40min. At a temperature of 40℃ and a stirring speed of 600r / min, add 2.62g of acidic ZSM-5 with a silicon-aluminum ratio (Si / Al) of 200 for in-situ reaction for 3h. After the reaction, transfer the above solution to a reactor and seal it, react at 120℃ for 36h, cool it to room temperature after the reaction, centrifuge the obtained light blue precipitate, wash it with deionized water 4 times, wash it with anhydrous ethanol 4 times, and dry it at 100℃ for 15h to obtain a light yellow rod-shaped precursor. After grinding the above light yellow rod-shaped precursor into uniform powder, put it in a quartz boat, send it into a heating kettle, heat it at a heating rate of 4℃ per minute in an air atmosphere, stop heating at 500℃, and keep it warm for 6h. After calcination, cool it to room temperature to obtain a bifunctional CeO2&ZSM-5 composite catalytic material. The mass ratio of CeO2 / ZSM-5 (Si / Al=200) in the composite catalytic material is 3:5.

[0040] Figure 2The XRD diagram of the composite catalyst prepared in Example 1-3 shows that the in-situ prepared CeO2 & ZSM-5 composite catalytic materials all show clear diffraction peaks of standard CeO2 (JCPDS PDF#43-1002) and ZSM-5 (JCPDS PDF#44-0003) cubic fluorite structures. The characteristic peaks at 2θ positions of 28.5°, 33.1°, 47.5°, 56.3°, 59.1°, 69.4°, 76.7° and 79.1° are respectively attributed to the (111), (200), (220), (311), (222), (400), (331) and (420) lattice planes of rod-shaped cerium dioxide. It can be seen from XRD that the composite material has many defect sites, which may be due to the in-situ reaction of adding ZSM-5 molecular sieves with large specific surface area and pore structure, which changes the combination of CeO2 and ZSM-5 and forms certain defects (O V ) structure, indicating that the uniform dispersion between CeO2 and ZSM-5 promotes the interaction between acidic and O V As active centers, they are evenly dispersed and can fully contact with the reaction substrate.

[0041] In this embodiment, a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst is used as follows:

[0042] The CeO2 / ZSM-5 (Si / Al=200) composite catalytic material prepared in this embodiment was placed in a high-pressure reactor to catalytically convert the C7 oligomer derived from lignin, with the C7 oligomer derived from lignin as the reaction substrate, 10 ml of water as the reaction solvent, 0.03 g of the composite catalytic material prepared in this embodiment and 0.03 g of the C7 oligomer derived from lignin were added, the reactor was filled with hydrogen at room temperature, the reaction pressure of hydrogen was 2.5 MPa, the temperature was raised to a reaction temperature of 260°C, the reaction time was 150 min, the stirring speed was 900 r / min, after the reaction was completed, it was cooled to room temperature, the liquid product was taken, and qualitative and quantitative detection was performed using a gas chromatography-mass spectrometer and a gas chromatograph. The analysis results are shown in Table 1.

[0043] Embodiment 4:

[0044] The preparation method of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst in this embodiment includes the following steps:

[0045] First, weigh 3.66g of cerium nitrate hexahydrate and 40.30g of sodium hydroxide and dissolve them in 140ml of deionized water, stir and dissolve them thoroughly, and form a light blue solution to react for 40min. At a temperature of 50℃ and a stirring speed of 500r / min, add 3.625g of acidic ZSM-5 with a silicon-aluminum ratio (Si / Al) of 45 to react for 2h. After the reaction, transfer the above solution to a reactor and seal it, react at 120℃ for 24h, cool it to room temperature after the reaction, centrifuge the obtained light blue precipitate, wash it 3 times with deionized water, wash it 3 times with anhydrous ethanol, and dry it at 120℃ for 15h to obtain a light yellow rod-shaped precursor. After grinding the above light yellow rod-shaped precursor into uniform powder, put it in a quartz boat and send it into a heating kettle. In an air atmosphere, heat it at a heating rate of 3℃ per minute, stop heating at 400℃, and keep it warm for 4h. After calcination, cool it to room temperature to obtain a bifunctional CeO2&ZSM-5 composite catalytic material. The mass ratio of CeO2 / ZSM-5 (Si / Al=45) in the composite catalytic material is 2:5.

[0046] In this embodiment, a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst is used as follows:

[0047] The CeO2 / ZSM-5 composite catalytic material prepared in this embodiment was placed in a high-pressure reactor to catalytically convert the C7 oligomer derived from lignin, with the C7 oligomer derived from lignin as the reaction substrate, 10 ml of water as the reaction solvent, 0.03 g of the composite catalytic material prepared in this embodiment and 0.03 g of the C7 oligomer derived from lignin were added, the reactor was filled with hydrogen at room temperature, the reaction pressure of hydrogen was 2 MPa, the temperature was raised to a reaction temperature of 240°C, the reaction time was 120 min, the stirring speed was 800 r / min, after the reaction was completed, it was cooled to room temperature, the liquid product was taken, and qualitative and quantitative detection was performed using a gas chromatography-mass spectrometer and a gas chromatograph. The analysis results are shown in Table 1.

[0048] Embodiment 5:

[0049] The preparation method of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst in this embodiment includes the following steps:

[0050] First, weigh 3.56g of cerium nitrate hexahydrate and 39.0g of sodium hydroxide and dissolve them in 140ml of deionized water, stir and dissolve them thoroughly, and form a light blue solution to react for 40min. At a temperature of 30℃ and a stirring speed of 600r / min, add 1.45g of acidic ZSM-5 with a silicon-aluminum ratio (Si / Al) of 45 for 2h. After the reaction, transfer the above solution to a reactor and seal it. React at 120℃ for 24h. After the reaction, cool it to room temperature. Centrifuge the obtained light blue precipitate, wash it with deionized water 3 times, wash it with anhydrous ethanol 3 times, and dry it at 100℃ for 15h to obtain a light yellow rod-shaped precursor. After grinding the above light yellow rod-shaped precursor into uniform powder, put it in a quartz boat and send it into a heating kettle. In an air atmosphere, heat it at a heating rate of 3℃ per minute. Stop heating when it reaches 400℃ and keep it warm for 4h. After calcination, cool it to room temperature to obtain a bifunctional CeO2&ZSM-5 composite catalytic material. The mass ratio of CeO2 / ZSM-5 (Si / Al=45) in the composite catalytic material is 5:5.

[0051] In this embodiment, a bifunctional rod-shaped CeO2 & ZSM-5 composite catalyst is used as follows:

[0052] The CeO2 / ZSM-5 (Si / Al=45) composite catalytic material prepared in this embodiment is placed in a high-pressure reactor to catalytically convert the C7 oligomer derived from lignin, with the C7 oligomer derived from lignin as the reaction substrate, 10ml of water as the reaction solvent, 0.03g of the composite catalytic material prepared in this embodiment and 0.03g of the C7 oligomer derived from lignin are added, the reactor is filled with hydrogen at room temperature, the reaction pressure of hydrogen is 2MPa, the temperature is raised to the reaction temperature of 240°C, the reaction time is 120min, the stirring speed is 800r / min, after the reaction is completed, it is cooled to room temperature, and the liquid product is taken, and qualitative and quantitative detection is performed using a gas chromatography-mass spectrometer and a gas chromatograph. The analysis results are shown in Table 1.

[0053] Embodiment 6:

[0054] The preparation method of a bifunctional rod-shaped CeO2&ZSM-5 composite catalyst in this embodiment includes the following steps:

[0055] First, weigh 3.47g of cerium nitrate hexahydrate and 38.0g of sodium hydroxide and dissolve them in 140ml of deionized water, stir and dissolve them thoroughly, and form a light blue solution to react for 30min. At a temperature of 35℃ and a stirring speed of 500r / min, add 2.50g of acidic ZSM-5 with a silicon-aluminum ratio (Si / Al) of 45 for in-situ reaction for 2h. After the reaction, transfer the above solution to a reactor and seal it, react at 100℃ for 24h, cool it to room temperature after the reaction, centrifuge the obtained light blue precipitate, wash it 3 times with deionized water, wash it 3 times with anhydrous ethanol, and dry it at 90℃ for 10h to obtain a light yellow rod-shaped precursor. After grinding the above light yellow rod-shaped precursor into uniform powder, put it in a quartz boat and send it into a heating kettle. In an air atmosphere, heat it at a heating rate of 3℃ per minute, stop heating at 400℃, and keep it warm for 4h. After calcination, cool it to room temperature to obtain a bifunctional CeO2&ZSM-5 composite catalytic material. The mass ratio of CeO2 / ZSM-5 (Si / Al=45) in the composite catalytic material is 3:5.

[0056] In this embodiment, a bifunctional rod-shaped CeO2 & ZSM-5 composite catalyst is used as follows:

[0057] The CeO2 / ZSM-5 composite catalytic material prepared in this embodiment is placed in a high-pressure reactor for catalytic conversion of lignin oil. Lignin oil is used as a reaction substrate, 10 ml of water is used as a reaction solvent, 0.03 g of the composite catalytic material prepared in this embodiment and 0.03 g of lignin oil are added, and the reactor is filled with hydrogen at room temperature. The reaction pressure of hydrogen is 2 MPa, the temperature is raised to a reaction temperature of 240°C, the reaction time is 360 min, the stirring speed is 800 r / min, and after the reaction is completed, the temperature is cooled to room temperature, and the liquid product is taken. Qualitative and quantitative detection is performed using a gas chromatography-mass spectrometer and a gas chromatograph. The conversion rate of lignin oil is 89.4%, and the selectivity of aromatics is 72.4%.

[0058] Table 1 Catalytic performance of different composite catalytic materials in Examples 1 to 5 on lignin-derived C7 oligomers

[0059]

[0060] The catalytic performance of different composite catalytic materials on lignin-derived C7 oligomers in Examples 1 to 5 in Table 1 shows that the composite catalytic material provided by the present invention is prepared by an in-situ hydrothermal reaction method as a rod-shaped precursor, which is dried and calcined at high temperature in an air atmosphere to obtain an acidic and O V The method is simple and unique, and oxygen vacancies (O V ) and acidic, O VThe acidity promotes the catalytic activity, reduces the energy barrier of the bond energy, and improves the interaction between the carrier and the substrate. V The formation increases the surface adsorption of oxygen (O ads ) content, increasing the lattice oxygen (O latt ) mobility; ZSM-5 structure has a large specific surface area and pore structure, which can fully contact with the reaction substrate and improve the selectivity of bond breaking. The optimal mass ratio of CeO2 / ZSM-5 in the catalyst is 3:5, the conversion rate can reach 99.9%, and the selectivity of the main product benzene reaches 46.1% to 83.5%. The above results all show that the composite catalyst synthesized by this method has a good catalytic conversion effect on lignin oil and lignin-derived C7 oligomers.

[0061] It should be noted that the embodiments described herein are only partial embodiments of the present invention, rather than all implementations of the present invention, and the embodiments are only exemplary, and their role is only to provide a more intuitive and clear way to understand the content of the present invention, rather than to limit the technical solutions described in the present invention. Without departing from the concept of the present invention, all other implementation methods that can be thought of by ordinary technicians in this field without creative work, and other simple replacements and various changes to the technical solutions of the present invention, all belong to the protection scope of the present invention.

Claims

1. A bifunctional rod-shaped CeO 2 & Preparation method of ZSM-5 composite catalyst, It is characterized in that The method comprises the following steps: Weigh cerium nitrate hexahydrate and sodium hydroxide, dissolve in deionized water to obtain a light blue solution, and let stand; After standing, add acidic ZSM-5 molecular sieve while stirring to form a white turbid solution, and react for a period of time; After the reaction is completed, the white turbid solution is transferred into a reaction kettle for hydrothermal reaction to obtain a blue precipitate, which is washed with deionized water and anhydrous ethanol respectively and then dried to obtain a rod-shaped precursor; The precursor is calcined at high temperature in air atmosphere to obtain bifunctional rod-shaped CeO with uniform oxygen vacancies and acidity. 2 &ZSM-5 composite catalyst.

2. A bifunctional rod-shaped CeO as claimed in claim 1 2 & Preparation method of ZSM-5 composite catalyst, It is characterized in that The method is specifically as follows: Weigh cerium nitrate hexahydrate and sodium hydroxide solids in a mass ratio of (0.1-0.2) g:(1.1-1.2) g, dissolve in deionized water, wherein the ratio of solid addition amount to deionized water is (0.1-0.2) g:(0.33-0.34) g, and let stand for 20-40 minutes; After standing, add acidic ZSM-5 molecular sieve while stirring to form a white turbid solution, wherein the mass ratio of cerium nitrate hexahydrate to ZSM-5 is (0.1-0.2) g: (0.06-0.08) g, and react for 1 h to 3 h; After the reaction is completed, the white turbid solution is transferred into a reactor, and reacted in the reactor at 80° C. to 120° C. for 12 h to 36 h to obtain a blue precipitate, which is washed with deionized water and anhydrous ethanol for 2 to 4 times, respectively, and then dried at 60° C. to 120° C. for 5 h to 15 h to obtain a rod-shaped precursor; The rod-shaped precursor is calcined at 300°C to 500°C for 2h to 6h in an air atmosphere to obtain a bifunctional rod-shaped CeO with uniform oxygen vacancies and acidity. 2 &ZSM-5 composite catalyst.

3. A bifunctional rod-shaped CeO as claimed in claim 2 2 & Preparation method of ZSM-5 composite catalyst, It is characterized in that The rod-shaped precursor is a light yellow solid.

4. A bifunctional rod-shaped CeO 2 &Application of ZSM-5 composite catalyst, It is characterized in that The bifunctional rod-shaped CeO 2 &ZSM-5 composite catalyst is used for catalytic conversion of lignin oil and its oligomers.

5. A bifunctional rod-shaped CeO as claimed in claim 4 2 &Application of ZSM-5 composite catalyst, It is characterized in that The application specifically comprises: dissolving a reaction substrate in a reaction solvent to obtain a reaction solution, and subjecting the reaction solution to a catalytic reaction with hydrogen under anaerobic conditions, wherein the reaction substrate is lignin oil or lignin-derived C 7 One of the oligomers, the reaction solvent is water.

6. A bifunctional rod-shaped CeO as claimed in claim 5 2 &Application of ZSM-5 composite catalyst, It is characterized in that The temperature of the catalytic reaction is 220° C. to 60° C., the reaction is carried out under stirring, the stirring speed is 700 r / min to 100 r / min, the hydrogen pressure is 1.5 MPa to 2.5 MPa, and the reaction time is 1.5 h to 2.5 h.

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