Preparation method of hierarchical pore ZSM-5 confinement metal catalyst and application of hierarchical pore ZSM-5 confinement metal catalyst in aromatic phenol and ether conversion

Abstract

The invention discloses a preparation method of a hierarchical pore ZSM-5 confinement metal catalyst and application of the hierarchical pore ZSM-5 confinement metal catalyst in aromatic phenol and ether conversion. The metal in the catalyst is one of Ni, Cu, Co, Mo, Fe, Mg, Sn, Zn, Pd, Pt, Ir and Rh, the metal loading capacity is 1.1-4.5 wt.%, and the silicon-aluminum ratio is 25-150; the diameter of metal particles in the catalyst is 0.5-7 nm. Compared with a metal-molecular sieve bifunctional material synthesized by a traditional impregnation method and an ion exchange method, the metal-molecular sieve bifunctional material has a unique hierarchical pore structure, high-dispersion metal particles and enhanced metal-carrier interaction, and the conversion rate of catalytic aromatic phenol and ether compounds is greater than 90% under the conditions that the temperature is 130-200 DEG C, the hydrogen pressure is 2-4MPa, the reaction time is 2-5h and the mass of a catalyst / a substrate is 3: 5-1: 1. In five circular reactions, the substrate conversion rate and the product yield index are reduced by less than 3%, and the stability is good.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial catalysis and bioenergy conversion, and particularly relates to a novel catalyst for catalyzing the conversion of aromatic phenols and ethers and a preparation method thereof. Background Art

[0002] Biomass is the only renewable carbon resource that can be used to produce liquid biofuels. Fully utilizing renewable biomass resources will help alleviate the fossil energy crisis and achieve the "dual carbon" goals. Lignin, abundant in biomass, is rich in C6 aromatic structures and provides a renewable raw material for the synthesis of compounds such as cycloalkanes. Cycloalkanes, with their high energy density and excellent combustion properties, are ideal components of high-quality fuels. However, lignin is extremely complex in structure, and exploratory experiments using aromatic phenols and ether chemicals with typical lignin structural functional groups as lignin model compounds have become the mainstream. Therefore, the catalytic conversion of lignin-derived phenolic and ether compounds via hydrodeoxygenation reactions has important application significance.

[0003] Transition metal-molecular sieve bifunctional catalysts have been shown to have excellent hydrodeoxygenation capabilities. Metal active sites (Ni, Co, Mo, etc.) catalyze the hydrogenation reaction of the reactants (Appl. Catal. B Environ., 2017, 202, 557-568), while zeolites (ZSM-5, β, Y, etc.) with rich acidity, high hydrothermal stability and surface area catalyze the dehydration reaction to produce alkane compounds. However, metal-bifunctional catalysts prepared by traditional impregnation, ion exchange, and deposition precipitation methods usually have problems such as uneven metal particles, poor dispersion, and easy agglomeration leading to catalyst deactivation (Appl. Catal. B Environ., 2020, 267, 118690). Post-treatment of molecular sieves (such as etching and pore expansion) makes it difficult to maintain their structural integrity. Literature research shows that there are currently no reports on the efficient conversion of various aromatic phenols and ether compounds at low temperatures (<200°C) using molecular sieves encapsulated with inexpensive metal catalysts.

[0004] In recent years, encapsulating metal clusters in zeolite micropores or cavities has become an efficient strategy for preparing ultrafine metal nanoparticles. The closed environment provided by zeolites can spatially confine metal particles, improve the stability of metals, and prevent sintering and leaching of metal species during the catalytic process. In addition, the successful encapsulation of metal nanoclusters can also achieve their close coexistence with zeolite acidic sites, further enhancing the activity of the hydrodeoxygenation reaction through the synergistic effect between the dual functional sites (Green Chem. 2019, 21, 3744-3768). In situ synthesis of zeolite-confined metal particles is a feasible method to improve dispersibility, but reports on encapsulating metal nanoparticles in high aluminum content molecular sieves are very limited (ACS Catal., 2022, 12, 1847-1856). The main reasons are: high aluminum content easily leads to failure in the formation of MFI structure, and the metal precursor may precipitate prematurely before the zeolite crystallizes, resulting in failure of encapsulation of metal species. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention has developed an in situ synthesis strategy, using Al(OH)3 as the aluminum source, and confining metals (Ni, Cu, Co, etc.) to a molecular sieve with a multi-level pore structure through an in situ two-step hydrothermal method; compared with traditional catalysts, the implementation of this technology solves the problems of low substrate conversion rate and poor catalyst stability existing in the current technology, and achieves high conversion rate (>90%) and yield (>80%) of aromatic phenols and ether compounds under mild conditions (130-180°C), and shows good stability in multiple cycle experiments (the conversion rate and yield indicators decreased by less than 5% after 5 cycles), achieving low-temperature high activity and high stability in the reaction.

[0006] The present invention provides a preparation method of a hierarchical pore ZSM-5 confined metal catalyst and its application in catalyzing the conversion of lignin-derived aromatic phenols and ether compounds.

[0007] The present invention aims to improve the activity and stability of inexpensive metal catalysts for the hydrodeoxygenation of aromatic phenols and ether compounds under mild conditions. A ZSM-5 confined metal catalyst is designed and synthesized through an in situ two-stage synthesis strategy.

[0008] The technical solutions of the present invention are as follows:

[0009] A hierarchical ZSM-5 confined metal catalyst, denoted as M@ZSM-5, wherein M is one of Ni, Cu, Co, Mo, Fe, Mg, Sn, Zn, Ir, Pt, or Rh, and the loading amount of M is in the range of 1.1-4.5 wt.%. The catalyst has a silicon-to-aluminum ratio in the range of 25-150, a metal particle diameter in the range of 0.5-7 nm, and a typical hierarchical porous structure of micropores and mesopores.

[0010] The preparation method of the multi-level porous ZSM-5 confined metal catalyst of the present invention comprises the following steps:

[0011] a) Tetraethyl orthosilicate, a 40% aqueous solution of tetrapropylammonium hydroxide, Al(OH)3 powder, and sodium hydroxide were weighed and placed in deionized water to form a suspension, and the suspension was stirred and aged at room temperature for 20-26 hours to obtain a synthetic gel;

[0012] b) weighing a metal nitrate hydrate and 3-(2-aminoethylamino)propyltrimethoxysilane, placing them in deionized water, and stirring until a dark blue complex solution is formed; then adding the solution to the synthesis gel obtained in step a) under stirring, transferring the resulting mixture to a polytetrafluoroethylene-lined stainless steel autoclave, first performing rotary hydrothermal pre-nucleation at 60-80° C. for 4-10 hours, then hydrothermally crystallizing at 160-190° C. for 12-24 hours, cooling to room temperature, filtering and separating a precipitate, washing three times with deionized water, and drying the precipitate to obtain a catalyst precursor;

[0013] c) The dried catalyst precursor is calcined at 400-550° C. for 3-6 h, and then reduced in a hydrogen atmosphere at 400-550° C. for 3-6 h to obtain M@ZSM-5.

[0014] In the method, the molar ratio of tetraethyl orthosilicate and Al(OH)3 is 25-150:1; the molar ratio of metal nitrate hydrate and 3-(2-aminoethylamino)propyltrimethoxysilane is 1:2; and the concentration of metal nitrate hydrate in the dark blue complex solution is 6.2-24.8 mg / mL.

[0015] In the method, the amount of sodium hydroxide used is 0.114-0.686 mg / mL H2O.

[0016] In the described method, the M@ZSM-5 catalyst is formulated according to a metal M / (M+SiO2+Al2O3) mass ratio of 1.1-4.5 wt.%, and SiO2 and Al2O3 are calculated based on the mass of tetraethyl orthosilicate and Al(OH)3.

[0017] Application of the hierarchical pore ZSM-5 confined metal catalyst prepared by the present invention in the conversion of aromatic phenols and ethers.

[0018] The application of hierarchical ZSM-5 confined metal catalyst in the conversion of aromatic phenols and ethers includes the following steps:

[0019] a) The reaction solvent, catalyst, reaction substrate, internal standard and mixture are added to a reactor, and the gas in the reactor is replaced with hydrogen three times before the reaction begins, and the pressure in the reactor is filled with hydrogen to a target pressure of 2 MPa-4 MPa at room temperature;

[0020] b) heating the reactor to 180-200°C and starting stirring for 2-5 hours;

[0021] c) After the reaction, stirring was stopped and the temperature was lowered to room temperature. The air was then slowly released and the kettle was opened to separate the liquid product and the catalyst. The product was qualitatively and quantitatively analyzed using a mass spectrometer-gas chromatography, and the conversion rate of the substrate was >90%.

[0022] In the application of the hierarchical pore ZSM-5 confined metal catalyst in the conversion of aromatic phenols and ethers, the aromatic phenol and ether reaction substrate is one of guaiacol, phenol, p-cresol, anisole, diphenyl ether, and 2-phenoxy-1-phenylethanol, and the mass ratio of the catalyst to the reaction substrate is 3:5-1:1; the reaction solvent is selected from one of isopropanol, n-hexane, and n-pentane.

[0023] The significant advantages of the present invention are:

[0024] 1. The multi-level porous ZSM-5 confined metal catalyst of the present invention is prepared using cheap chemicals as raw materials, with low cost and simple and easy preparation process, and consumes less time, materials and energy.

[0025] 2. The hierarchical ZSM-5 confined metal catalyst of the present invention has a significant new structural feature, namely, the metal nanoparticles are mainly located in the ZSM-5 pores, with a small amount located on its surface.

[0026] 3. The hierarchical ZSM-5 confined metal catalyst described in this invention exhibits excellent activity in the hydrodeoxygenation of aromatic phenols and ethers. Compared to conventional metal-molecular sieve bifunctional catalysts, this catalyst's unique hierarchical pore structure, highly dispersed metal particles, strong metal-support interaction, and substrate enrichment and enhanced diffusion during the reaction significantly improve catalytic activity, product selectivity, and reaction rate. At a reaction temperature of 180°C, the conversion rate of phenolic and etheric compounds exceeded 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Transmission electron microscopy (TEM) images and particle size statistics of the catalyst described in Example 1.

[0028] Figure 2 This is the XRD pattern of the catalyst described in Example 1.

[0029] Figure 3 This is the N2 adsorption-desorption isotherm diagram of the catalyst described in Example 1. DETAILED DESCRIPTION

[0030] In order to make the contents of the present invention easier to understand, the technical solutions of the present invention are further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0031] Example 1

[0032] Preparation of hierarchical ZSM-5 confined Ni catalyst with a Ni loading of 4.5 wt.% and a Si / Al ratio of 25

[0033] a) Weigh 3.13 g of tetraethyl orthosilicate, 2.18 g of 40% tetrapropylammonium hydroxide aqueous solution, and 0.0468 g of powdered Al(OH)3.

[0034] 24 mg of NaOH (0.686 mg / mL) was mixed in 35 mL of deionized water and stirred at room temperature for 20 h to obtain a synthetic gel.

[0035] b) 0.178 g of Ni(NO₃)₂·6H₂O and 0.279 g of 3-(2-aminoethylamino)propyltrimethoxysilane were weighed and added with 7.2 mL of deionized water, stirring until a dark blue complex solution (nickel nitrate hexahydrate concentration was 24.8 mg / mL) was obtained. This solution was then added dropwise to the synthesis gel from step a) while stirring. The resulting mixture was transferred to a 100 mL polytetrafluoroethylene hydrothermal reactor and subjected to rotary hydrothermal heating at 80°C for 4 hours for prenucleation, followed by hydrothermal crystallization at 160°C for 12 hours. After cooling to room temperature, the light blue precipitate was isolated by filtration, washed three times with deionized water, and dried to obtain a catalyst precursor.

[0036] c) The dried catalyst precursor was calcined at 550° C. for 6 h, and then reduced at 550° C. for 6 h in a hydrogen atmosphere to obtain a catalyst with a loading of 4.5 wt.% and a silicon-aluminum ratio of 25.

[0037] Attachment Figure 1 The TEM images of the catalyst samples described in this example are included, which verify the successful encapsulation of the metal inside the molecular sieve. According to the particle size measurement statistics, the average diameter of the Ni nanoparticles prepared under this condition is 2nm and they are highly dispersed in the catalyst. Figure 2 The XRD spectrum of the catalyst described in this example shows that there are obvious ZSM-5 characteristic peaks, and no characteristic peaks of metal Ni are observed, indicating that metal Ni has not agglomerated and is highly dispersed in the catalyst.

[0038] Example 2

[0039] Preparation of hierarchical ZSM-5 confined Ni catalyst with a Ni loading of 3.4 wt.% and a Si / Al ratio of 25

[0040] a) Weigh 3.13 g of tetraethyl orthosilicate, 2.18 g of 40% tetrapropylammonium hydroxide aqueous solution, and 0.0468 g of powdered Al(OH)3.

[0041] 24 mg of NaOH (0.686 mg / mL) was mixed in 35 mL of deionized water and stirred at room temperature for 22 h to obtain the synthetic gel.

[0042] b) 0.134 g of Ni(NO₃)₂·6H₂O and 0.209 g of 3-(2-aminoethylamino)propyltrimethoxysilane were weighed and added with 7.2 mL of deionized water, stirring until a dark blue complex solution (nickel nitrate hexahydrate concentration was 18.6 mg / mL) was obtained. This solution was then added dropwise to the synthesis gel from step a) while stirring. The resulting mixture was transferred to a 100 mL polytetrafluoroethylene hydrothermal reactor and subjected to rotary hydrothermal heating at 80°C for 6 h for prenucleation, followed by hydrothermal crystallization at 170°C for 16 h. After cooling to room temperature, the light blue precipitate was isolated by filtration, washed three times with deionized water, and dried to obtain a catalyst precursor.

[0043] c) The dried catalyst precursor was calcined at 500°C for 5 h and then reduced at 500°C for 5 h in a hydrogen atmosphere to obtain a catalyst with a loading of 3.4

[0044] wt.%, catalyst with a silicon-aluminum ratio of 25.

[0045] Example 3

[0046] Preparation of hierarchical ZSM-5 confined Ni catalyst with a Ni loading of 2.3 wt.% and a Si / Al ratio of 25

[0047] a) Weigh 3.13 g of tetraethyl orthosilicate, 2.18 g of 40% tetrapropylammonium hydroxide aqueous solution, and 0.0468 g of powdered Al(OH)3.

[0048] 24 mg of NaOH was mixed in 35 mL of deionized water (0.686 mg / mL) and stirred at room temperature for 24 h to obtain the synthetic gel.

[0049] b) Weigh 0.089 g of Ni(NO₃)₂·6H₂O and 0.140 g of 3-(2-aminoethylamino)propyltrimethoxysilane, add 7.2 mL of deionized water, and stir until a dark blue complex solution (nickel nitrate hexahydrate concentration is 12.4 mg / mL) is obtained. This solution is then added dropwise to the synthesis gel from step a) while stirring. The resulting mixture is transferred to a 100 mL polytetrafluoroethylene hydrothermal reactor and subjected to rotary hydrothermal heating at 80°C for 8 hours for prenucleation, followed by hydrothermal crystallization at 180°C for 20 hours. After cooling to room temperature, the light blue precipitate is separated by filtration, washed three times with deionized water, and dried to obtain a catalyst precursor.

[0050] c) The dried catalyst precursor was calcined at 450 °C for 4 h and then reduced at 450 °C for 4 h in a hydrogen atmosphere to obtain a catalyst with a loading of 2.3

[0051] wt.%, catalyst with a silicon-aluminum ratio of 25.

[0052] Example 4

[0053] Preparation of hierarchical ZSM-5 confined Ni catalyst with a Ni loading of 1.1 wt.% and a Si / Al ratio of 25

[0054] a) Weigh 3.13 g of tetraethyl orthosilicate, 2.18 g of 40% tetrapropylammonium hydroxide aqueous solution, and 0.0468 g of powdered Al(OH)3.

[0055] 24 mg of NaOH (0.686 mg / mL) was mixed in 35 mL of deionized water and stirred at room temperature for 26 h to obtain the synthetic gel.

[0056] b) Weigh 0.0445 g of Ni(NO₃)₂·6H₂O and 0.0698 g of 3-(2-aminoethylamino)propyltrimethoxysilane, add 7.2 mL of deionized water, and stir until a dark blue complex solution (nickel nitrate hexahydrate concentration is 6.2 mg / mL) is obtained. This solution is then added dropwise to the synthesis gel from step a) while stirring. The resulting mixture is transferred to a 100 mL polytetrafluoroethylene hydrothermal reactor and subjected to rotary hydrothermal heating at 80°C for 10 h for prenucleation, followed by hydrothermal crystallization at 190°C for 24 h. After cooling to room temperature, the light blue precipitate is separated by filtration, washed three times with deionized water, and dried to obtain a catalyst precursor.

[0057] c) The dried catalyst precursor was calcined at 400°C for 3 h and then reduced at 400°C for 3 h in a hydrogen atmosphere to obtain a catalyst with a loading of 1.1

[0058] wt.%, catalyst with a silicon-aluminum ratio of 25.

[0059] Example 5

[0060] Preparation of hierarchical ZSM-5 confined Ni catalyst with a Ni loading of 4.5 wt.% and a Si / Al ratio of 50

[0061] a) Weigh 3.13 g of tetraethyl orthosilicate, 2.18 g of a 40% aqueous solution of tetrapropylammonium hydroxide, and 0.0234 g of powdered Al(OH)3.

[0062] 12 mg of NaOH was mixed in 35 mL of deionized water (0.343 mg / mL) and stirred at room temperature for 24 h to obtain the synthetic gel.

[0063] b) 0.178 g of Ni(NO₃)₂·6H₂O and 0.279 g of 3-(2-aminoethylamino)propyltrimethoxysilane were weighed and added with 7.2 mL of deionized water, stirring until a dark blue complex solution was obtained. The solution was then added dropwise to the synthesis gel from step a) while stirring. The resulting mixture was transferred to a 100 mL polytetrafluoroethylene hydrothermal reactor and subjected to rotary hydrothermal heating at 70°C for 4 hours for prenucleation, followed by hydrothermal crystallization at 160°C for 12 hours. After cooling to room temperature, the light blue precipitate was separated by filtration, washed three times with deionized water, and dried to obtain a catalyst precursor.

[0064] c) The dried catalyst precursor was calcined at 550°C for 4 h and then reduced in a hydrogen atmosphere at 550°C for 4 h to obtain a catalyst with a loading of 4.5

[0065] wt.%, catalyst with a silicon-aluminum ratio of 50.

[0066] Example 6

[0067] Preparation of hierarchical ZSM-5 confined Ni catalyst with a Ni loading of 4.5 wt.% and a Si / Al ratio of 100

[0068] a) Weigh 3.13 g of tetraethyl orthosilicate, 2.18 g of 40% tetrapropylammonium hydroxide aqueous solution, and 0.0117 g of powdered Al(OH)3.

[0069] 6 mg of NaOH was mixed in 35 mL of deionized water (0.172 mg / mL) and stirred at room temperature for 24 h to obtain the synthetic gel.

[0070] b) Weigh 0.178 g of Ni(NO₃)₂·6H₂O and 0.279 g of 3-(2-aminoethylamino)propyltrimethoxysilane, add 7.2 mL of deionized water, and stir until a dark blue complex solution is obtained. This solution is then added dropwise to the synthesis gel from step a) while stirring. The resulting mixture is transferred to a 100 mL polytetrafluoroethylene hydrothermal autoclave and subjected to rotary hydrothermal heating at 70°C for 4 hours for prenucleation, followed by hydrothermal crystallization at 160°C for 12 hours. After cooling to room temperature, the light blue precipitate is separated by filtration, washed three times with deionized water, and dried to obtain a catalyst precursor.

[0071] c) The dried catalyst precursor was calcined at 550°C for 4 h and then reduced in a hydrogen atmosphere at 550°C for 4 h to obtain a catalyst with a loading of 4.5

[0072] wt.%, catalyst with silicon-aluminum ratio of 100.

[0073] Example 7

[0074] Preparation of hierarchical ZSM-5 confined Ni catalyst with a Ni loading of 4.5 wt.% and a Si / Al ratio of 150

[0075] a) Weigh 3.13 g of tetraethyl orthosilicate, 2.18 g of 40% tetrapropylammonium hydroxide aqueous solution, and 0.009 g of powdered Al(OH)3.

[0076] 4 mg of NaOH was mixed in 35 mL of deionized water (0.114 mg / mL) and stirred at room temperature for 24 h to obtain the synthetic gel.

[0077] b) Weigh 0.178 g of Ni(NO₃)₂·6H₂O and 0.279 g of 3-(2-aminoethylamino)propyltrimethoxysilane, add 7.2 mL of deionized water, and stir until a dark blue complex solution is obtained. While stirring, add this solution dropwise to the synthesis gel from step a). The resulting mixture is transferred to a 100 mL polytetrafluoroethylene hydrothermal autoclave and subjected to rotary hydrothermal heating at 60°C for 4 hours for prenucleation. Subsequently, hydrothermal crystallization is performed at 160°C for 12 hours. After cooling to room temperature, the light blue precipitate is separated by filtration, washed three times with deionized water, and dried to obtain a catalyst precursor.

[0078] c) The dried catalyst precursor was calcined at 550°C for 4 h and then reduced in a hydrogen atmosphere at 550°C for 4 h to obtain a catalyst with a loading of 4.5

[0079] wt.%, catalyst with a silicon-aluminum ratio of 150.

[0080] Example 8

[0081] Preparation of hierarchically porous ZSM-5 with a Si / Al ratio of 25 and confined different metal catalysts (Cu, Co, Mo, Fe, Mg, Sn, Zn, Pt, Ir, Rh, Pd)

[0082] a) Weigh 3.13 g of tetraethyl orthosilicate, 2.18 g of 40% tetrapropylammonium hydroxide aqueous solution, and 0.0468 g of powdered Al(OH)3.

[0083] 24 mg of NaOH was mixed in 35 mL of deionized water (0.114 mg / mL) and stirred at room temperature for 24 h to obtain the synthetic gel.

[0084] b) Weigh 0.6 mmol of metal M nitrate hydrate (M is one of Cu, Co, Fe, Mo, Sn, Mg, Zn, Pt, Ir, or Rh) and 0.279 g of 3-(2-aminoethylamino)propyltrimethoxysilane, add 7.2 mL of deionized water, and stir until a dark blue complex solution is obtained. The solution is then added dropwise to the synthesis gel from step a) while stirring.

[0085] The resulting mixture was transferred to a 100 mL polytetrafluoroethylene hydrothermal reactor and subjected to rotary hydrothermal heating at 80°C for 4 hours for pre-nucleation. It was then hydrothermally crystallized at 160°C for 12 hours. After cooling to room temperature, the precipitate was separated by filtration, washed three times with deionized water, and dried to obtain the catalyst precursor.

[0086] c) The dried catalyst precursor was calcined at 550°C for 4 h, and then reduced at 550°C for 4 h in a hydrogen atmosphere to obtain a multi-level porous

[0087] ZSM-5 confined metal catalyst.

[0088] Example 9

[0089] Guaiacol hydrodeoxygenation reaction

[0090] a) adding 93 mg (catalyst / substrate mass ratio of 3:5) of the catalyst obtained according to Example 1 and 10 mL of a n-hexane solution containing 0.125 mol / L guaiacol and 0.125 mol / L n-dodecane to a 50 mL autoclave;

[0091] b) The air in the autoclave was replaced with hydrogen three times, and then hydrogen was added to the autoclave until the initial pressure was 2 MPa. The temperature was raised to 180°C, the stirring rate was 300 rpm, and the reaction time was 4 h.

[0092] c) After the reaction is completed, stirring is stopped and the temperature is lowered to room temperature. The pressure is then released and the kettle is opened to separate the liquid product and the catalyst. The liquid product is qualitatively and quantitatively analyzed by mass spectrometry-gas chromatography to calculate the substrate conversion rate and product yield.

[0093] The calculation formula is as follows:

[0094]

[0095] The internal standard selected in this technical solution is n-dodecane, and the substrate concentration is selected to be 0.125 mol / L.

[0096] The reaction results are shown in Table 1.

[0097] Table 1. Results of guaiacol conversion using the multi-level pore confined catalyst described in Example 1

[0098]

[0099] The results show that the Ni@ZSM-5 hierarchical pore confinement catalyst with a Ni loading of 4.5 wt.% and a silicon-aluminum ratio of 25 efficiently catalyzes the conversion of guaiacol to cyclohexane at a reaction temperature of 180°C, with a yield of up to 98.2%. Compared with the existing technology, the conversion rate and cyclohexane yield are significantly improved.

[0100] Example 10

[0101] Guaiacol hydrodeoxygenation reaction

[0102] The embodiment is basically the same as Example 10, except that the catalyst used is the catalyst described in Example 2. The reaction results are shown in Table 2.

[0103] Table 2. Results of guaiacol conversion using the multi-level pore confined catalyst described in Example 2

[0104]

[0105] Example 11

[0106] Guaiacol hydrodeoxygenation reaction

[0107] The embodiment is basically the same as Example 10, except that the catalyst used is the catalyst described in Example 3. The reaction results are shown in Table 3.

[0108] Table 3. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 3

[0109]

[0110] Example 12

[0111] Guaiacol hydrodeoxygenation reaction

[0112] The embodiment is basically the same as Example 10, except that the catalyst used is the catalyst described in Example 4. The reaction results are shown in Table 4.

[0113] Table 4. Conversion results of guaiacol catalyzed by the multi-level pore confined catalyst described in Example 4

[0114]

[0115] Example 13

[0116] Guaiacol hydrodeoxygenation reaction

[0117] The embodiment is basically the same as Example 10, except that the catalyst used is the catalyst described in Example 5. The reaction results are shown in Table 5.

[0118] Table 5. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 5

[0119]

[0120] Example 14

[0121] Guaiacol hydrodeoxygenation reaction

[0122] The embodiment is basically the same as Example 10, except that the catalyst used is the catalyst described in Example 6. The reaction results are shown in Table 6.

[0123] Table 6. Results of guaiacol conversion catalyzed by the multi-level pore confined catalyst described in Example 6

[0124]

[0125] Example 15

[0126] Guaiacol hydrodeoxygenation reaction

[0127] The embodiment is basically the same as Example 10, except that the catalyst used is the catalyst described in Example 7. The reaction results are shown in Table 7.

[0128] Table 7. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 7

[0129]

[0130] Example 16

[0131] Guaiacol hydrodeoxygenation reaction

[0132] The embodiment is basically the same as Example 10, except that the catalyst used is the catalyst described in Example 8 and the reaction temperature is 200° C. The reaction results are shown in Table 8.

[0133] Table 8. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 8

[0134]

[0135] The results in Table 8 show that for various types of inexpensive metals, this method has a good catalytic effect on the conversion of guaiacol at 200°C, with a conversion rate of >90% and a cyclohexane yield of >82%.

[0136] Example 17

[0137] Guaiacol hydrodeoxygenation reaction

[0138] The embodiment is basically the same as Example 10, except that the reaction temperature is adjusted to 190° C. or 200° C. The reaction results are shown in Table 8.

[0139] Table 9. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 1

[0140]

[0141] Example 18

[0142] Guaiacol hydrodeoxygenation reaction

[0143] The implementation scheme is basically the same as Example 10, except that the amount of catalyst is adjusted to 124 mg or 155 mg (i.e., the catalyst-substrate mass ratio is 4:5 and 1:1). The reaction results are shown in Table 9.

[0144] Table 10. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 1

[0145]

[0146] Example 19

[0147] Guaiacol hydrodeoxygenation reaction

[0148] The embodiment is basically the same as Example 10, except that the initial hydrogen pressure is adjusted to 3 MPa or 4 MPa. The reaction results are shown in Table 10.

[0149] Table 11. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 1

[0150]

[0151] Example 20

[0152] Guaiacol hydrodeoxygenation reaction

[0153] The implementation scheme is basically the same as Example 10, except that the reaction time is adjusted to 2h, 3h or 5h.

[0154] As shown in Table 11.

[0155] Table 12. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 1

[0156]

[0157] Example 21

[0158] Guaiacol hydrodeoxygenation reaction

[0159] The embodiment is basically the same as Example 10, except that the reaction solvent is replaced with isopropanol or n-pentane. The reaction results are shown in Table 12.

[0160] Table 13. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 1

[0161]

[0162] The results in Tables 9-13 show that within the reaction conditions range: 180°C to 200°C, hydrogen pressure 2MPa-4MPa, reaction time 2h-5h, catalyst / substrate mass 3:5-1:1, the multi-level pore confined catalyst can efficiently catalyze the hydrodeoxygenation of guaiacol to cyclohexane, with a conversion rate of >90% and a cyclohexane yield of >90%.

[0163] Example 22

[0164] Cyclic stability test of catalyst for guaiacol hydrodeoxygenation reaction

[0165] The catalyst from Example 8 was filtered and separated, washed multiple times with n-hexane, and used in the hydrodeoxygenation of guaiacol under the same operating conditions as Example 8. This process was repeated four times, and the activity data for the catalyst after four cycles were measured. The reaction results are shown in Table 13.

[0166] Table 14. Guaiacol conversion results using the multi-level pore confined catalyst described in Example 1

[0167]

[0168] The results in Table 13 show that the catalytic activity of the catalyst remains stable after multiple cycles, and the substrate conversion rate and product yield indicators decrease by less than 3%, indicating that the catalyst has good cyclic stability.

[0169] Example 23

[0170] Hydrodeoxygenation of different aromatic phenols and ethers

[0171] The embodiment is basically the same as Example 10, except that the reaction substrates are replaced with 0.125 mol / L phenol, p-cresol, anisole, diphenyl ether, and 2-phenoxy-1-phenylethanol. The reaction results are shown in Table 14.

[0172] Table 15. Conversion results of aromatic phenols and ethers catalyzed by the multi-level pore confinement catalyst described in Example 1

[0173]

[0174] The results in Table 14 show that the multi-level pore confinement catalyst has high catalytic activity for the conversion of various aromatic phenols and ether compounds, with substrate conversion rates greater than 90% and cycloalkane yields greater than 80%.

[0175] The technical solutions disclosed and proposed by the present invention can be implemented by those skilled in the art by drawing on the content of this document and appropriately changing the conditions, routes, and other aspects. Although the methods and preparation techniques of the present invention have been described through preferred embodiments, it is obvious that those skilled in the art can modify or recombine the methods and technical routes described herein without departing from the content, spirit, and scope of the present invention to achieve the ultimate preparation technology. It is particularly important to point out that all similar substitutions and modifications that are obvious to those skilled in the art are considered to be included in the spirit, scope, and content of the present invention.

Claims

1. A hierarchical pore ZSM-5 confined metal catalyst, characterized in that: Expressed as M@ZSM-5, M is one of Ni, Cu, Co, Mo, Fe, Mg, Sn, Zn, Ir, Pt, Rh, or Pd, the metal loading range is 1.1-4.5 wt.%, the silicon-aluminum ratio of the catalyst ranges from 25-150, the metal particle diameter ranges from 0.5-7 nm, and it has a typical multi-level pore structure of micropores and mesopores.

2. The method for preparing the hierarchical ZSM-5 confined metal catalyst according to claim 1, characterized in that: The steps include: a) Tetraethyl orthosilicate, 40% tetrapropylammonium hydroxide aqueous solution, Al(OH)3 powder, and sodium hydroxide were weighed and placed in deionized water to form a suspension, and stirred and aged at room temperature for 20-26 hours to obtain a synthetic gel; b) weighing a metal nitrate hydrate and 3-(2-aminoethylamino)propyltrimethoxysilane, placing them in deionized water, and stirring until a dark blue complex solution is formed; then adding the solution to the synthesis gel obtained in step a) under stirring, transferring the resulting mixture to a polytetrafluoroethylene-lined stainless steel autoclave, first performing rotary hydrothermal pre-nucleation at 60-80° C. for 4-10 hours, then hydrothermally crystallizing at 160-190° C. for 12-24 hours, cooling to room temperature, filtering and separating a precipitate, washing three times with deionized water, and drying the precipitate to obtain a catalyst precursor; c) The dried catalyst precursor is calcined at 400-550° C. for 3-6 h, and then reduced in a hydrogen atmosphere at 400-550° C. for 3-6 h to obtain M@ZSM-5.

3. The preparation method according to claim 2, wherein: The molar ratio of tetraethyl orthosilicate to Al(OH)3 is 25-150:1; the molar ratio of metal nitrate hydrate to 3-(2-aminoethylamino)propyltrimethoxysilane is 1:2, and the concentration of metal nitrate hydrate in the obtained dark blue complex solution is 6.2-24.8 mg / mL.

4. preparation method as claimed in claim 2, is characterized in that, sodium hydroxide The dosage is 0.114-0.686 mg / mL H2O.

5. The preparation method according to claim 2, wherein: The M@ZSM-5 catalyst is formulated according to a metal M / (M+SiO2+Al2O3) mass ratio of 1.1-4.5wt.%, and SiO2 and Al2O3 are calculated based on the mass of tetraethyl orthosilicate and Al(OH)3.

6. Use of the hierarchical pore ZSM-5 confined metal catalyst according to claim 1 in the conversion of aromatic phenols and ethers.

7. Use of the hierarchical ZSM-5 confined metal catalyst according to claim 6 in the conversion of aromatic phenols and ethers, characterized in that: The steps include: a) adding the reaction solvent, catalyst, reaction substrate, internal standard and fully mixed into a reactor, replacing the gas in the reactor with hydrogen before the reaction starts, and filling the reactor with hydrogen to the target pressure of 2 MPa-4 MPa at room temperature; b) heating the reactor to 180-200°C and starting stirring for 2-5 hours; c) After the reaction was completed, stirring was stopped and the temperature was lowered to room temperature. The air was then released and the kettle was opened to separate the liquid product and the catalyst. The product was qualitatively and quantitatively analyzed using a mass spectrometer-gas chromatography, and the conversion rate of the substrate was >90%.

8. The use of the hierarchical pore ZSM-5 confined metal catalyst in the conversion of aromatic phenols and ethers as claimed in claim 7, characterized in that: The aromatic phenol and ether reaction substrate is one of guaiacol, phenol, p-cresol, anisole, diphenyl ether, and 2-phenoxy-1-phenylethanol.

9. The use of the hierarchical pore ZSM-5 confined metal catalyst in the conversion of aromatic phenols and ethers as claimed in claim 7, characterized in that: The mass ratio of the catalyst to the reaction substrate is 3:5-1:1; the reaction solvent is selected from one of isopropanol, n-hexane and n-pentane.

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