A hydrodeoxygenation catalyst, its preparation method and application

Abstract

The present disclosure provides a hydrodeoxygenation catalyst and a preparation method and application thereof. The hydrodeoxygenation catalyst comprises an acidic zeolite carrier and an active bimetallic component, the acidic zeolite carrier is a zeolite nanotube, and the active bimetallic component comprises a first metal and a second metal, the first metal is Ru, and the second metal is a metal other than Ru. The hydrodeoxygenation catalyst provided by the present application has acidic sites of traditional zeolites, ensures basic deoxygenation capacity, has a large specific surface area, provides sufficient sites for loading active metals, at the same time, provides a large contact area of reactants, improves reaction conversion rate, the hydrodeoxygenation catalyst has a large number of uniform and connected microporous and mesoporous structures, enhances the intracrystalline mass transfer rate of reactants and reaction intermediates, improves selectivity, and reduces the occurrence of carbon deposition side reactions.

Description

Technical Field

[0001] This disclosure relates to the field of catalyst technology, and in particular to a hydrodeoxygenation catalyst, its preparation method, and its application. Background Technology

[0002] With the development of the aerospace industry, the requirements for fuel performance in aircraft (such as airplanes, rockets, and missiles) are constantly increasing. Traditional petroleum-based jet fuels (aviation kerosene and rocket kerosene) are mainly composed of saturated alkanes, and their density and calorific value have reached their limits. Developing high-density hydrocarbon fuels with cycloalkanes and polycyclic alkanes as the main components, which have the advantages of high density and high volumetric calorific value, has attracted significant attention from various countries. Using biomass as a raw material to prepare liquid aerospace fuels can not only open up new avenues for energy security but also provide an important pathway for the high-value utilization of biomass.

[0003] Lignin is the only naturally occurring aromatic hydrocarbon polymer in nature. Its reserves in nature are vast, accounting for 10-35 wt% of biomass, yet its energy density is as high as 40%. Lignin is not edible for humans, and its use will not negatively impact food supply, nor does it compete with humans for food. Lignin depolymerization produces lignin-derived biomass, containing high concentrations of phenolic monomers, dimers, and oligomers, making it an ideal raw material for the production of cycloalkanes. Using lignin-derived biomass as a raw material for hydrodeoxygenation reactions to obtain high-quality cycloalkanes is a highly promising approach for the production of aerospace fuels.

[0004] Bifunctional catalysts possess both hydrogenation and deoxygenation sites, enabling the direct conversion of oxygen-containing compounds into hydrocarbon products. Zeolite molecular sieves, with their excellent shape selectivity, abundant acidic sites, and good hydrothermal and thermal stability, are the most widely studied catalyst supports with superior overall catalytic performance. However, the limited micropores of zeolite molecular sieves restrict intracrystalline diffusion and mass transfer of large molecular reactants and intermediates such as branched phenol monomers and dimers. Furthermore, the longer mass transfer pathways may lead to increased side reactions and catalyst deactivation. While possessing deoxygenation capabilities, the strongly acidic sites of molecular sieves also readily cause deoxygenation intermediates to condense and deposit carbon. Therefore, focusing on enhancing the intracrystalline diffusion and mass transfer capabilities of molecular sieve supports, regulating deoxygenation capabilities, and mitigating side reactions and carbon deposition holds promise for further improving the efficiency and selectivity of hydrodeoxygenation reactions. Summary of the Invention

[0005] This disclosure provides a hydrodeoxygenation catalyst, its preparation method, and its application, to at least solve one of the technical problems existing in the prior art.

[0006] According to a first aspect of this disclosure, a hydrodeoxygenation catalyst is provided, the catalyst comprising an acidic zeolite support and an active bimetallic component, the acidic zeolite support being zeolite nanotubes, and the active bimetallic component comprising a first metal and a second metal, the first metal being Ru, and the second metal being a metal other than Ru.

[0007] In one embodiment, the second metal is one of Co, Ni, and Fe.

[0008] In one embodiment, the active bimetallic component accounts for 1 to 15 wt% of the catalyst;

[0009] The mass ratio of the first metal to the second metal in the active bimetallic component is 1:1 to 20.

[0010] According to a second aspect of this disclosure, a method for preparing a hydrodeoxygenation catalyst is provided, comprising:

[0011] Zeolite nanotubes, a first metal salt solution, and a second metal salt solution are mixed, stirred, heated until the water evaporates, dried, and then calcined in an air atmosphere at 400–650°C. The mixture is then placed in a hydrogen-inert gas mixture and reduced with hydrogen at 200–300°C for 2–10 hours to obtain the hydrogenation deoxygenation catalyst.

[0012] In one embodiment, the method for preparing the zeolite nanotubes includes:

[0013] Preparation of intermediate A: 4,4′-dihydroxybiphenyl, 1,10-dibromodecane and potassium hydroxide were added to an ethanol solution and reacted under inert gas reflux with stirring. After the reaction was completed, the mixture was cooled and washed with hot ethanol and water to obtain intermediate A.

[0014] Preparation of intermediate B: Intermediate A and quinine ring were added to acetonitrile and reacted under reflux of inert gas at a temperature of 60-80℃. After the reaction was completed, the mixture was cooled, and diethyl ether was added to precipitate the product. The product was then washed, dried, and intermediate B was obtained.

[0015] Preparation of the carrier: Intermediate B was added to deionized water, followed by sodium hydroxide and hydrated aluminum sulfate. Silica gel was added dropwise and stirred. The mixture was crystallized at 140–160 °C for at least 6 days. After crystallization, the mixture was centrifuged, washed with water, and dried. Then, it was calcined in air at 400–650 °C for 4–12 h to obtain the zeolite nanotubes.

[0016] In one embodiment, in the preparation step of intermediate A: the mass ratio of 4,4′-dihydroxybiphenyl, 1,10-dibromodecane, potassium hydroxide and ethanol is 1-2:10-14:1:70-100;

[0017] The reaction is carried out under inert gas reflux conditions with stirring, at a temperature of 60–80°C and a stirring time of 12–24 h.

[0018] In one embodiment, in the preparation step of intermediate B: the mass ratio of intermediate A, quinine ring and acetonitrile is 1:0.5-1:30-70; in the preparation step of the carrier: the mass ratio of silica gel, hydrated aluminum sulfate, intermediate B, sodium hydroxide and deionized water is 2-5:0.1-0.5:1:0.2-0.8:20-50.

[0019] According to a third aspect of this disclosure, a hydrodeoxygenation catalyst or a hydrodeoxygenation catalyst prepared by any of the above-described embodiments is provided for use in the preparation of cycloalkanes from biomass derivatives.

[0020] In one embodiment, the hydrodeoxygenation catalyst and the biomass derivative are added to a hydrodeoxygenation solvent, mixed, and reacted under heating and a hydrogen atmosphere to obtain cycloalkanes.

[0021] In one embodiment, the hydrodeoxygenation solvent is one or a mixture of n-decane, dodecane, tetradecane, and hexadecane;

[0022] The reaction temperature is 170–280℃, the reaction time is 0.5–4h, and the hydrogen pressure is 1–6MPa.

[0023] The biomass derivative is one or more of guaiacol, phenol, aromatic ketone, and aromatic alcohol;

[0024] The mass ratio of the hydrodeoxygenation catalyst, biomass derivative, and hydrodeoxygenation solvent is 1:0.5-10:50-2000.

[0025] Compared with existing technologies, the advantages of this application are as follows: 1) The hydrodeoxygenation catalyst provided by this application has the acidic sites of traditional zeolites, ensuring basic deoxygenation capacity; it also has a large specific surface area, providing sufficient sites for loading active metals, and simultaneously providing a larger contact area for reactants, thus improving reaction conversion rate; 2) The hydrodeoxygenation catalyst of this application has a large number of uniform and interconnected micropores and mesopores, enhancing the intracrystalline mass transfer rate of reactants and reaction intermediates, improving selectivity while reducing the occurrence of carbon deposition side reactions; 3) The preparation method of the catalyst provided by this invention is simple and convenient. Under the premise of synthesizing a template agent with a specific structure, the traditional zeolite crystallization synthesis method is adopted, which is conducive to large-scale promotion and application.

[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0027] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which:

[0028] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0029] Figure 1 Transmission electron micrographs of the catalyst according to embodiments of the present disclosure are shown (where a) is a zeolite nanotube bundle and b) is a zeolite nanotube;

[0030] Figure 2 The image shows a scanning electron microscope image of a conventional zeolite (where a) is a ZSM-5 zeolite molecular sieve and b) is a nanosheet zeolite.

[0031] Figure 3 Nitrogen adsorption maps of zeolite nanotubes, zeolite nanosheets, and ZSM-5 according to embodiments of the present disclosure are shown.

[0032] Figure 4 The pore size distribution diagrams of zeolite nanotubes, zeolite nanosheets, and ZSM-5 according to embodiments of the present disclosure are shown.

[0033] Figure 5 The diagram illustrates the intracrystalline mass transfer rate of cyclohexane in zeolite nanotubes, zeolite nanosheets, and ZSM-5 according to embodiments of the present disclosure. Detailed Implementation

[0034] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0035] In view of the deficiencies of existing technologies, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. This invention utilizes a template agent with a unique structure to synthesize nanotube-shaped zeolites. This increases the specific surface area of ​​traditional zeolites while introducing a uniform mesoporous structure connected to micropores, enhancing the mass transfer efficiency of reactants and reaction intermediates within the zeolite crystals. Simultaneously, the introduction of a second metal into the active metal Ru enhances the dispersion of Ru particles on the support surface and improves anti-agglomeration ability, thereby increasing catalyst lifetime. The combination of zeolite nanotubes and a bimetallic compound can improve the conversion rate and cycloalkane selectivity of the hydrodeoxygenation reaction.

[0036] This invention aims to provide a hydrodeoxygenation catalyst for the preparation of cycloalkanes from biomass derivatives, overcoming the problems of low specific surface area and disconnected micropores and mesopores in traditional zeolite molecular sieves, thereby achieving high conversion efficiency, good selectivity, and fewer side reactions.

[0037] Based on this, according to an embodiment of the present disclosure, the present invention provides a hydrodeoxygenation catalyst (hereinafter referred to as "catalyst"), the catalyst comprising an acidic zeolite support and an active bimetallic component, wherein the acidic zeolite support is a zeolite nanotube, and the active bimetallic component comprises a first metal and a second metal, wherein the first metal is Ru, and the second metal is a metal other than Ru.

[0038] Preferably, the second metal is one of Co, Ni, and Fe.

[0039] Preferably, the zeolite nanotubes have a hollow tubular structure with an inner diameter of approximately 3 mm. The tube walls are composed of Si, Al, and O elements, and the tube walls have characteristic zeolite micropores of about 0.5 nm. The zeolite nanotubes have a large specific surface area (up to 720 m²). 2 (above / g), far exceeding that of traditional Zsm-5 zeolite molecular sieves and zeolite nanosheets.

[0040] Preferably, the active bimetallic component accounts for 1 to 15 wt% of the catalyst by mass; exemplary, the active bimetallic component accounts for 1 wt%, 3 wt%, 5 wt%, 8 wt%, 10 wt%, 13 wt%, and 15 wt% of the catalyst by mass.

[0041] The mass ratio of the first metal to the second metal in the active bimetallic component is 1:1 to 20. For example, the mass ratio of the first metal to the second metal is 1:1, 1:3, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18, or 1:20.

[0042] The hydrodeoxygenation catalyst provided in this application introduces a second metal into the active metal Ru, enhancing the dispersion and anti-agglomeration ability of Ru particles on the support surface and improving catalyst lifetime. Furthermore, the catalyst utilizes zeolite nanotubes as a support, increasing its surface area while introducing a uniform mesoporous structure connected to micropores, thus enhancing the mass transfer efficiency of reactants and reaction intermediates within the zeolite crystals. This allows the catalyst to improve the conversion rate of biomass derivatives and the selectivity of cycloalkanes during the hydrodeoxygenation reaction of biomass derivatives.

[0043] Secondly, this disclosure also provides a method for preparing a hydrodeoxygenation catalyst, comprising:

[0044] Zeolite nanotubes, a first metal salt solution, and a second metal salt solution are mixed, stirred, heated until the water evaporates, dried, and then calcined in an air atmosphere at 400–650°C. The mixture is then placed in a hydrogen-inert gas mixture and reduced with hydrogen at 200–300°C for 2–10 hours to obtain a hydrodeoxygenation catalyst.

[0045] For example, zeolite nanotubes, a first metal salt solution, and a second metal salt solution are mixed and stirred using an impregnation method, then heated to 80°C to evaporate the moisture, dried in an oven at 105°C, calcined in an air atmosphere at 400–650°C, and then placed in a hydrogen-inert gas mixture and reduced with hydrogen at 200–300°C for 2–10 hours to obtain a hydrodeoxygenation catalyst.

[0046] For example, the first metal salt solution includes, but is not limited to, ruthenium chloride (RuCl3) and ruthenium nitrate (Ru(NO3)3).

[0047] The second metal salt solution includes, but is not limited to, cobalt chloride (CoCl2), ferric chloride (FeCl3), nickel chloride (NiCl2), cobalt nitrate (Co(NO3)2), ferric nitrate (Fe(NO3)3), nickel nitrate (Ni(NO3)2), cobalt sulfate (CoSO4), ferric sulfate (Fe2(SO4)3), and nickel sulfate (NiSO4).

[0048] For example, preferably, when zeolite nanotubes and the first / second metal salt solution are mixed, stirred, heated to evaporate moisture, dried, and then calcined in an air atmosphere at 400-650°C, the calcination temperature in the air atmosphere can be 400°C, 450°C, 500°C, 550°C, 600°C, or 650°C, and the calcination time is at least 4 hours; wherein the mixing and stirring time of zeolite nanotubes and the first / second metal salt solution is 6-24 hours.

[0049] Preferably, in the hydrogen-inert gas mixture, the volume percentage of hydrogen in the mixture is 10%, and the inert gas includes, but is not limited to, one or more of nitrogen (N2), argon (Ar), and helium (He).

[0050] In some embodiments, the method for preparing zeolite nanotubes includes:

[0051] Preparation of intermediate A: 4,4′-dihydroxybiphenyl, 1,10-dibromodecane and potassium hydroxide were added to an ethanol solution and stirred under reflux of an inert gas. After the reaction was completed, the mixture was cooled and washed with hot ethanol and water, respectively, to obtain intermediate A.

[0052] Preparation of intermediate B: Intermediate A and quinine ring were added to acetonitrile and refluxed at 60-80°C under an inert gas (e.g., N2, Ar, He) for at least 12 hours. After the reaction was completed, the mixture was cooled, and diethyl ether was added to precipitate the product. The product was then washed with diethyl ether and dried to obtain intermediate B.

[0053] Preparation of the carrier: Intermediate B was added to deionized water, followed by sodium hydroxide and hydrated aluminum sulfate. Silica gel was added dropwise and stirred at room temperature. The mixture was then crystallized at 140–160 °C for at least 6 days. After crystallization, the mixture was centrifuged, washed with water, and dried. Then, it was calcined in air at 400–650 °C for 4–12 h to obtain zeolite nanotubes.

[0054] Preferably, in the preparation step of intermediate A, the mass ratio of 4,4′-dihydroxybiphenyl, 1,10-dibromodecane, potassium hydroxide and ethanol is 1-2:10-14:1:70-100; preferably, potassium hydroxide can also be replaced by sodium hydroxide.

[0055] Preferably, in the preparation step of intermediate A, the reaction under inert gas reflux and stirring conditions is carried out at a reaction temperature of 60-80°C and a stirring time of 12-24 hours.

[0056] Preferably, in the preparation step of intermediate B, the mass ratio of intermediate A, quinine ring and acetonitrile is 1:0.5 to 1:30 to 70.

[0057] Preferably, in the carrier preparation step, the mass ratio of the silica gel, hydrated aluminum sulfate, intermediate B, sodium hydroxide, and deionized water is 2–5:0.1–0.5:1:0.2–0.8:20–50. The silica gel can be HS-30 silica gel.

[0058] Preferably, in the preparation step of the carrier, the stirring time at room temperature is 1 to 5 hours. The crystallization temperature is 140 to 160°C. For example, the crystallization temperature can be 140°C, 150°C, or 160°C.

[0059] Thirdly, the embodiments of this disclosure also provide the application of hydrodeoxygenation catalysts or hydrodeoxygenation catalysts obtained by the preparation methods described above in the preparation of cycloalkanes from biomass derivatives.

[0060] In some embodiments, the hydrodeoxygenation catalyst and the biomass derivative are added to a hydrodeoxygenation solvent, mixed evenly, and reacted under heating and a hydrogen atmosphere to obtain cycloalkanes.

[0061] In some embodiments, the hydrodeoxygenation solvent is one or a mixture of n-decane, dodecane, tetradecane, and hexadecane;

[0062] The reaction temperature is 170–280℃, the reaction time is 0.5–4h, and the hydrogen pressure is 1–6MPa.

[0063] The biomass derivative is one or more of guaiacol, phenol, aromatic ketones, and aromatic alcohols; guaiacol, phenol, aromatic ketones, and aromatic alcohols are lignin depolymerization products. Aromatic ketones include, but are not limited to, benzophenone. Aromatic alcohols include, but are not limited to, benzyl alcohol.

[0064] The mass ratio of the hydrodeoxygenation catalyst, biomass derivative, and hydrodeoxygenation solvent is 1:0.5-10:50-2000.

[0065] The present application will be further described in detail below with reference to the embodiments and accompanying drawings:

[0066] Example 1

[0067] A method for preparing a hydrodeoxygenation catalyst, comprising:

[0068] Step (1): Add 1.6g of 4,4′-dihydroxybiphenyl, 12.5g of 1,10-dibromodecane and 1g of potassium hydroxide to 100g of ethanol solution, and stir the reaction under nitrogen reflux (reaction temperature is 75℃, stirring for 12h). After the reaction is completed, cool the mixture and wash it with hot ethanol and water respectively to obtain intermediate A.

[0069] Step (2): Add 0.5g of intermediate A and 0.35g of quinine ring to 25g of acetonitrile, and heat at 70℃. 、 The reaction was carried out under nitrogen reflux for 12 hours. After the reaction was completed and cooled, diethyl ether was added to precipitate the product. The product was washed with diethyl ether and dried to obtain intermediate B.

[0070] Step (3): Add 0.113g of intermediate B to 4.45g of deionized water, then add 0.067g of sodium hydroxide, 0.027g of hydrated aluminum sulfate, and dropwise add 0.5g of HS-30 silica gel. Stir at room temperature for 3 hours, then crystallize in a polytetrafluoroethylene autoclave at 150℃ for 7 days. After crystallization, centrifuge, wash with water, and dry. Then calcine at 550℃ in air for 6 hours to obtain zeolite nanotubes.

[0071] Step (4): The first metal salt solution (RuCl3), the second metal salt solution (CoCl2), and the zeolite nanotubes were mixed and stirred for 10 hours. Then, the mixture was heated to 80°C to evaporate the moisture and dried in an oven at 105°C. After that, it was calcined in an air atmosphere at 550°C for 4 hours, and then placed in a 10% hydrogen-nitrogen mixture and reduced with hydrogen at 250°C for 4 hours to obtain a catalyst with a Ru-Co bimetallic loading of 10%, wherein the mass ratio of Ru to Co was 1:15.

[0072] Application of a hydrodeoxygenation catalyst in the preparation of cycloalkanes from biomass derivatives:

[0073] The reaction involved adding 20 mg of the catalyst from step (4) and 20 mg of guaiacol to a 20 g n-dodecane solution. The hydrogen pressure in the reactor was 2 MPa, the temperature was 240 °C, and the reaction was carried out for 2 hours. The conversion rate of guaiacol was 99.9%, and the selectivity of cyclohexane was 99%.

[0074] Example 2

[0075] A method for preparing a hydrodeoxygenation catalyst, comprising:

[0076] Step (1): Add 1g of 4,4′-dihydroxybiphenyl, 10g of 1,10-dibromodecane and 1g of potassium hydroxide to 70g of ethanol solution, and stir the reaction under nitrogen reflux (reaction temperature is 60℃, stirring for 12h). After cooling, wash with hot ethanol and water respectively to obtain intermediate A.

[0077] Step (2): Add 1g of intermediate A and 0.5g of quinine ring to 30g of acetonitrile, and react at 60℃ under nitrogen reflux for 12h. After the reaction is completed and cooled, add diethyl ether to precipitate the product, wash with diethyl ether, and dry to obtain intermediate B.

[0078] Step (3): Add 1g of intermediate B to 20g of deionized water, then add 0.2g of sodium hydroxide, 0.1g of hydrated aluminum sulfate, and 2g of HS-30 silica gel dropwise. Stir at room temperature for 3 hours, then crystallize in a polytetrafluoroethylene autoclave at 150℃ for 7 days. After crystallization, centrifuge, wash with water, and dry. Then calcine at 550℃ in air for 6 hours to obtain zeolite nanotubes.

[0079] Step (4): The first metal salt solution (RuCl3), the second metal salt solution (CoCl2), and the zeolite nanotubes were mixed and stirred for 10 hours. Then, the mixture was heated to 80°C to evaporate the moisture and dried in an oven at 105°C. After that, it was calcined in air at 550°C for 4 hours and then reduced with hydrogen at 250°C for 4 hours in a 10% hydrogen-nitrogen mixture to obtain a catalyst with a Ru-Co bimetallic loading of 1%, wherein the mass ratio of Ru to Co was 1:10.

[0080] Application of a hydrodeoxygenation catalyst in the preparation of cycloalkanes from biomass derivatives:

[0081] The process involved adding 20 mg of the catalyst from step (4) and 10 mg of guaiacol to a 1 g n-dodecane solution, with a reactor hydrogen pressure of 1 MPa, a temperature of 280 °C, and a reaction time of 0.5 hours. The conversion rate of guaiacol was 90%, and the selectivity of cyclohexane was 70%.

[0082] Example 3

[0083] A method for preparing a hydrodeoxygenation catalyst, comprising:

[0084] Step (1): Add 2g of 4,4′-dihydroxybiphenyl, 14g of 1,10-dibromodecane and 1g of potassium hydroxide to 100g of ethanol solution, and stir the reaction under nitrogen reflux (reaction temperature is 80℃, stirring for 12h). After cooling, wash with hot ethanol and water respectively to obtain intermediate A.

[0085] Step (2): Add 1g of intermediate A and 1g of quinine ring to 70g of acetonitrile, and react at 80℃ under nitrogen reflux for 12h. After the reaction is completed and cooled, add diethyl ether to precipitate the product, wash with diethyl ether, and dry to obtain intermediate B.

[0086] Step (3): Add 1g of intermediate B to 50g of deionized water, then add 0.8g of sodium hydroxide, 0.5g of hydrated aluminum sulfate, and dropwise add 5g of HS-30 silica gel. Stir at room temperature for 3 hours, then crystallize in a polytetrafluoroethylene autoclave at 150℃ for 7 days. After crystallization, centrifuge, wash with water, and dry. Then calcine at 550℃ in air for 6 hours to obtain zeolite nanotubes.

[0087] Step (4): The first metal salt solution, the second metal salt solution, and the zeolite nanotubes were mixed and stirred for 10 hours. Then, the mixture was heated to 80°C to evaporate the moisture and dried in an oven at 105°C. After that, it was calcined in an air atmosphere at 550°C for 4 hours and then reduced with hydrogen at 250°C for 4 hours in a 10% hydrogen-nitrogen mixture to obtain a catalyst with a Ru-Co bimetallic loading of 15%, wherein the mass ratio of Ru to Co was 1:20.

[0088] Application of a hydrodeoxygenation catalyst in the preparation of cycloalkanes from biomass derivatives:

[0089] The reaction involved adding 20 mg of the catalyst from step (4) and 200 mg of guaiacol to a 40 g n-dodecane solution. The reactor was subjected to a hydrogen pressure of 6 MPa and a temperature of 170 °C for 4 hours. The conversion rate of guaiacol was 20%, and the selectivity of cyclohexane was 60%.

[0090] Example 4

[0091] A method for preparing a hydrodeoxygenation catalyst, comprising:

[0092] Step (1): Add 1.6g of 4,4′-dihydroxybiphenyl, 12.5g of 1,10-dibromodecane and 1g of potassium hydroxide to 100g of ethanol solution. Under nitrogen reflux, stir the reaction (reaction temperature is 65℃, stirring for 12h). After cooling, wash with hot ethanol and water respectively to obtain intermediate A.

[0093] Step (2): Add 0.5g of intermediate A and 0.35g of quinine ring to 20g of acetonitrile, and react at 65℃ under nitrogen reflux for 12h. After the reaction is completed and cooled, add diethyl ether to precipitate the product, wash with diethyl ether, and dry to obtain intermediate B.

[0094] Step (3): Add 0.113g of intermediate B to 4.45g of deionized water, then add 0.067g of sodium hydroxide, 0.027g of hydrated aluminum sulfate, and dropwise add 0.5g of HS-30 silica gel. Stir at room temperature for 3 hours, then crystallize in a polytetrafluoroethylene autoclave at 150℃ for 7 days. After crystallization, centrifuge, wash with water, and dry. Then calcine at 550℃ in air for 6 hours to obtain zeolite nanotubes.

[0095] Step (4): The first metal salt solution (RuCl3), the second metal salt solution (NiCl2), and the zeolite nanotubes were mixed and stirred for 10 hours. Then, the mixture was heated to 80°C to evaporate the moisture and dried in an oven at 105°C. The mixture was then calcined in air at 550°C for 4 hours and then reduced with hydrogen at 250°C for 4 hours in a 10% hydrogen-nitrogen mixture to obtain a catalyst with a Ru-Ni bimetallic loading of 5%, wherein the mass ratio of Ru to Ni was 1:5.

[0096] Application of a hydrodeoxygenation catalyst in the preparation of cycloalkanes from biomass derivatives:

[0097] The reaction involved adding 20 mg of the catalyst from step (4) and 20 mg of phenol to 17 g of n-decane. The reactor was subjected to a hydrogen pressure of 1 MPa and a temperature of 190 °C for 2 hours. The conversion rate of phenol was 99.9% and the selectivity of cyclohexane was 95%.

[0098] Example 5

[0099] A method for preparing a hydrodeoxygenation catalyst, comprising:

[0100] Step (1): Add 1.6g of 4,4′-dihydroxybiphenyl, 12.5g of 1,10-dibromodecane and 1g of potassium hydroxide to 100g of ethanol solution. Under nitrogen reflux, stir the reaction (reaction temperature is 80℃, stirring for 12h). After cooling, wash with hot ethanol and water respectively to obtain intermediate A.

[0101] Step (2): Add 0.5g of intermediate A and 0.35g of quinine ring to 20g of acetonitrile, and react at 80℃ under nitrogen reflux for 12h. After the reaction is completed and cooled, add diethyl ether to precipitate the product, wash with diethyl ether, and dry to obtain intermediate B.

[0102] Step (3): Add 0.113g of intermediate B to 4.45g of deionized water, then add 0.067g of sodium hydroxide, 0.027g of hydrated aluminum sulfate, and dropwise add 0.5g of HS-30 silica gel. Stir at room temperature for 3 hours, then crystallize in a polytetrafluoroethylene autoclave at 150℃ for 7 days. After crystallization, centrifuge, wash with water, and dry. Then calcine at 550℃ in air for 6 hours to obtain zeolite nanotubes.

[0103] Step (4): The first metal salt solution (RuCl3), the second metal salt solution (FeCl3), and the zeolite nanotubes were mixed and stirred for 10 hours. Then, the mixture was heated to 80°C to evaporate the moisture and dried in an oven at 105°C. The mixture was then calcined in air at 550°C for 4 hours and then reduced with hydrogen at 250°C for 4 hours in a 10% hydrogen-nitrogen mixture to obtain a catalyst with a Ru-Fe bimetallic loading of 8%, wherein the mass ratio of Ru to Fe was 1:12.

[0104] Application of a hydrodeoxygenation catalyst in the preparation of cycloalkanes from biomass derivatives:

[0105] The reaction involved adding 20 mg of the catalyst from step (4) and 30 mg of aromatic ketone to 17 g of n-tetradecane. The reactor was subjected to a hydrogen pressure of 3 MPa and a temperature of 210 °C for 1.5 hours. The conversion rate of benzophenone was 98%, and the selectivity of cyclohexane was 85%.

[0106] Example 6

[0107] A method for preparing a hydrodeoxygenation catalyst, comprising:

[0108] Step (1): Add 1.6g of 4,4′-dihydroxybiphenyl, 12.5g of 1,10-dibromodecane and 1g of potassium hydroxide to 100g of ethanol solution. Under nitrogen reflux, stir the reaction (reaction temperature is 70℃, stirring for 12h). After cooling, wash with hot ethanol and water respectively to obtain intermediate A.

[0109] Step (2): Add 0.5g of intermediate A and 0.35g of quinine ring to 30g of acetonitrile and react at 75℃ under nitrogen reflux for 12h. After the reaction is completed and cooled, add diethyl ether to precipitate the product. Wash with diethyl ether and dry to obtain intermediate B.

[0110] Step (3): Add 0.113g of intermediate B to 4.45g of deionized water, then add 0.067g of sodium hydroxide, 0.027g of hydrated aluminum sulfate, and dropwise add 0.5g of HS-30 silica gel. Stir at room temperature for 3 hours, then crystallize in a polytetrafluoroethylene autoclave at 150℃ for 7 days. After crystallization, centrifuge, wash with water, and dry. Then calcine at 550℃ in air for 6 hours to obtain zeolite nanotubes.

[0111] Step (4): The first metal salt solution (RuCl3), the second metal salt solution (FeCl3), and the zeolite nanotubes were mixed and stirred for 10 hours. Then, the mixture was heated to 80°C to evaporate the moisture and dried in an oven at 105°C. The mixture was then calcined in air at 550°C for 4 hours and then reduced with hydrogen at 250°C for 4 hours in a 10% hydrogen-nitrogen mixture to obtain a catalyst with a Ru-Fe bimetallic loading of 8%, wherein the mass ratio of Ru to Fe was 1:12.

[0112] Application of a hydrodeoxygenation catalyst in the preparation of cycloalkanes from biomass derivatives:

[0113] The reaction involved adding 20 mg of the catalyst from step (4) and 20 mg of aromatic alcohol to 20 g of n-hexadecane. The reactor was subjected to a hydrogen pressure of 2 MPa and a temperature of 240 °C for 2 hours. The conversion rate of benzyl alcohol was 97%, and the selectivity of cyclohexane was 90%.

[0114] Comparative Example 1

[0115] Comparative Example 1 is a comparative example of Example 1.

[0116] The catalyst preparation method and cycloalkanes preparation method of Comparative Example 1 are largely the same as those of Example 1, except that Comparative Example 1 uses conventional ZSM-5 zeolite molecular sieves for metal loading ( Figure 2 a) A Ru-Co bimetallic catalyst with a loading of 10% was obtained, wherein the mass ratio of Ru to Co was 1:15. Cycloalkanes were prepared under the same conditions, and the evaluation results showed that the guaiacol conversion rate was 95% and the cyclohexane selectivity was 94%.

[0117] Comparative Example 2

[0118] Comparative Example 2 is a comparative example of Example 1.

[0119] The catalyst preparation method and cycloalkanes preparation method of Comparative Example 2 are largely the same as those of Example 1, except that Comparative Example 1 uses zeolite nanosheets for metal loading ( Figure 2 (b) A catalyst with a Ru-Co bimetallic loading of 10% was obtained, wherein the mass ratio of Ru to Co was 1:15. Cycloalkanes were prepared under the same conditions, and the evaluation results showed that the guaiacol conversion rate was 97% and the cyclohexane selectivity was 96%.

[0120] Comparative Example 3

[0121] Comparative Example 3 is a comparative example of Example 1.

[0122] The catalyst preparation method and cycloalkanes preparation method of Comparative Example 3 are largely the same as those of Example 1, except that: no metal salt solution is added in step (4), and cycloalkanes are prepared under the same conditions. The evaluation results show that the conversion rate of guaiacol is 80% and the selectivity of cyclohexane is 10%.

[0123] Comparative Example 4

[0124] Comparative Example 4 is a comparative example of Example 1.

[0125] The catalyst preparation method and cycloalkanes preparation method of Comparative Example 4 are largely the same as those of Example 1, except that in step (4), only single metal Ru loading is performed to obtain a catalyst with Ru metal loading of 10%, and cycloalkanes are prepared under the same conditions. The evaluation results show that the conversion rate of guaiacol is 97% and the selectivity of cyclohexane is 98%.

[0126] Characterization and Testing

[0127] 1) The catalyst prepared in Example 1 was subjected to transmission electron microscopy (TEM) testing. The TEM image is shown below. Figure 1 As shown. From Figure 1 As can be seen, the prepared zeolite nanotubes have a typical tubular structure, are distributed in bundles, have a single tube diameter of about 4 nm, and have very thin walls between tubes, exhibiting one-dimensional structural characteristics.

[0128] In addition, this application also performed scanning electron microscopy on traditional zeolites, such as... Figure 2 As shown, where Figure 2 a is a scanning electron microscope image of ZSM-5 zeolite molecular sieve. Figure 2 b is a scanning electron microscope image of zeolite nanosheets. From Figure 2 As can be seen, zeolite nanosheets exhibit a typical sheet-like structure, displaying two-dimensional characteristics, with the sheets stacked in a staggered manner. ZSM-5, on the other hand, exhibits a typical blocky structure, displaying three-dimensional characteristics. Both... Figure 1 The zeolite nanotubes exhibit significant differences in microstructure.

[0129] 2) Nitrogen adsorption tests were performed on the zeolite nanotubes prepared in Example 1, as well as traditional zeolite nanosheets and ZSM-5 zeolite molecular sieves. The results are as follows: Figure 3 As shown.

[0130] from Figure 3 As can be seen, the zeolite nanotubes prepared in Example 1 adsorb nitrogen much more effectively than the zeolite nanosheets and ZSM-5 zeolite molecular sieves. The specific surface area of ​​the aircraft nanotubes, calculated using BET, is as high as 720 m². 2 / g, higher than zeolite nanosheets and ZSM-5.

[0131] 3) The pore size distribution of the zeolite nanotubes prepared in Example 1, as well as traditional zeolite nanosheets and ZSM-5 zeolite molecular sieves, was tested, and the results are as follows: Figure 4 As shown.

[0132] from Figure 4 As can be seen, zeolite nanotubes, zeolite nanosheets and ZSM-5 all have microporous structures below 1 nm, but the mesoporous distribution of zeolite nanotubes is much higher than that of zeolite nanosheets and ZSM-5, and the distribution is more concentrated.

[0133] 4) The intracrystalline mass transfer rate of cycloalkanes (specifically cyclohexane) in zeolite nanotubes, traditional zeolite nanosheets, and ZSM-5 zeolite molecular sieves was tested, and the results are as follows: Figure 5 As shown.

[0134] from Figure 5 As can be seen, the intracrystalline mass transfer rate of cycloalkanes within the three zeolite molecular sieve supports, from fastest to slowest, is zeolite nanotubes, zeolite nanosheets, and ZSM-5. The intracrystalline mass transfer rate of zeolite nanotubes is significantly higher than that of the other two supports. This is closely related to the high specific surface area and uniform, interconnected microporous structure of zeolite nanotubes. The higher intracrystalline mass transfer rate of zeolite nanotubes to the products is beneficial for improving the conversion rate and selectivity of the catalytic reaction.

[0135] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0136] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0137] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A hydrodeoxygenation catalyst, characterized by: The catalyst comprises an acidic zeolite carrier and an active bimetallic component, the acidic zeolite carrier is a zeolite nanotube, the active bimetallic component comprises a first metal and a second metal, the first metal is Ru, and the second metal is a metal other than Ru, and the second metal is one of Co, Ni and Fe; The preparation method of the zeolite nanotube comprises: Preparation of intermediate A: 4,4'-dihydroxydiphenyl, 1,10-dibromoadamantane and potassium hydroxide are added into an ethanol solution, and stirred under inert gas reflux conditions, and after the reaction is completed, the mixture is cooled, washed with hot ethanol and water, and intermediate A is obtained; Preparation of intermediate B: intermediate A and quinine ring are added into acetonitrile, and reacted under inert gas reflux at a temperature of 60-80°C, and after the reaction is completed, the mixture is cooled, precipitated by adding diethyl ether, washed, dried, and intermediate B is obtained; Preparation of the carrier: intermediate B is added into deionized water, and then sodium hydroxide and aluminum sulfate hydrate are added, and silica gel is added dropwise, and stirred, and crystallized at 140-160°C for at least 6 days; After crystallization is completed, the mixture is centrifuged, washed with water, and dried, and then calcined at 400-650°C in air for 4-12h, and the zeolite nanotube is obtained.

2. The hydrodeoxygenation catalyst of claim 1, wherein: The active bimetallic component accounts for 1-15wt% of the mass of the catalyst; The mass ratio of the first metal to the second metal in the active bimetallic component is 1:1-20.

3. Process for the preparation of a hydrodeoxygenation catalyst according to any one of claims 1-2, characterized in that: Comprise: The zeolite nanotube, a first metal salt solution and a second metal salt solution are mixed, stirred, heated to evaporate water, dried, and then calcined at 400-650°C in air, and then placed in a hydrogen-inert gas mixture, and reduced by hydrogen at 200-300°C for 2-10h, and the hydrodeoxygenation catalyst is obtained.

4. The method of claim 3, wherein: In the preparation step of intermediate A: the mass ratio of 4,4'-dihydroxydiphenyl, 1,10-dibromoadamantane, potassium hydroxide and ethanol is 1-2:10-14:1:70-100; The stirring reaction under inert gas reflux conditions is at a reaction temperature of 60-80°C and a stirring time of 12-24h.

5. The method of claim 3, wherein: In the preparation step of intermediate B: the mass ratio of intermediate A, quinine ring and acetonitrile is 1:0.5-1:30-70; In the preparation step of the carrier: the mass ratio of silica gel, aluminum sulfate hydrate, intermediate B, sodium hydroxide, deionized water is 2-5:0.1-0.5:1:0.2-0.8:20-50.

6. The hydrodeoxygenation catalyst of any one of claims 1-2 or the hydrodeoxygenation catalyst obtained by the preparation method of any one of claims 3-5 is used in the preparation of naphthene from biomass derivatives.

7. Use according to claim 6, characterized in that: The hydrodeoxygenation catalyst and the biomass derivative are added into a hydrodeoxygenation solvent, mixed, and reacted under heating and hydrogen atmosphere, and naphthene is obtained.

8. Use according to claim 7, characterized in that: The hydrodeoxygenation solvent is a mixture of one or more of n-decane, dodecane, tetradecane and hexadecane; The reaction temperature is 170-280°C, the reaction time is 0.5-4h, and the hydrogen pressure is 1-6MPa; The biomass derivative is one or more of guaiacol, phenol, aromatic ketone and aromatic alcohol; The mass ratio of the hydrodeoxygenation catalyst, the biomass derivative, and the hydrodeoxygenation solvent is 1:0.5-10:50-2000.

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