Bimetal hydrogen-free deoxidation catalyst as well as preparation method and application thereof

Abstract

The invention relates to the field of green aviation fuel production, in particular to a bimetallic hydrogen-free deoxidation catalyst and a preparation method and application thereof. The preparation method of the bimetallic hydrogen-free deoxidation catalyst comprises the following steps: mixing a template agent solution and a buffer agent to obtain a buffer template solution; adding a silicon source and aminopropyltriethoxysilane into the buffer template solution, stirring, carrying out a heating reaction, filtering to obtain a solid, and sequentially washing, refluxing, filtering, washing and drying the solid to obtain a surface-functionalized SBA-15-NH2 carrier; and dispersing the surface-functionalized SBA-15-NH2 carrier in an ethanol solution, then adding cobalt salt and nickel salt, stirring, filtering to obtain a solid, washing, drying and calcining to obtain the bimetallic hydrogen-free deoxidation catalyst. Due to the fact that the dispersing amount of metal particles on the surface of the carrier is larger, and amino groups and silane groups are introduced, acid sites and active sites of the catalyst are greatly increased, and the activity and selectivity of the catalyst are greatly improved.

Description

Technical Field

[0001] The invention relates to the field of green aviation fuel production, and in particular to a bimetallic hydrogen-free deoxidation catalyst and a preparation method and application thereof. Background Art

[0002] The growing and rapid development of the global economy and industry has increased the demand for sustainable energy. In the past, the continued dependence on fossil fuels has brought tremendous pressure to the ecological environment, fossil energy reserves and energy industry. To this end, scientists are exploring environmentally friendly biofuels to replace fossil fuels, such as bioalcohol, hydrogen, biodiesel and biojet fuel. The deoxygenation process for preparing biojet fuel involves two main means: one is hydrogen-free decarboxylation (DCX) and decarbonylation (DCN), and the other is hydrodeoxygenation (HDO). Hydrogen-free decarboxylation and decarbonylation reactions are to remove oxygen-containing groups in the form of CO2 / CO in biomass raw material molecules by cracking CO bonds under N2 conditions to generate positive (C15) and positive (C17) hydrocarbons. Hydrodeoxygenation (HDO) refers to the removal of O in the molecular structure by hydrogen addition reaction. Compared with HDO, hydrogen-free decarboxylation and decarbonylation reactions do not undergo hydrogenation reactions and do not contain solvents, so the process requires less energy and cost, and has greater cost advantages. Efficient decarboxylation and decarbonylation reactions depend on the design of efficient catalysts. Previous studies have explored the deoxygenation reaction using noble metal catalysts such as palladium (Pd) and platinum (Pt). However, noble metal catalysts are limited by resource scarcity and production costs. Although transition metals such as nickel (Ni), cobalt (Co), manganese (Mn), zinc (Zn) and copper (Cu) are also promising in deoxygenation reactions, they are subject to low product conversion rates and specific reaction conditions. Bimetallic catalysts have attracted much attention because they have higher activity than monometallic catalysts under similar reaction conditions. Among them, Ni and Co bimetallic catalysts supported by silicon-based carriers such as mesoporous silica (such as SBA-15) show stronger catalytic activity. However, the activity and selectivity of such catalysts still cannot meet the needs of industrial production and conversion of bio-jet fuel. Summary of the invention

[0003] In order to overcome the problem of low activity and selectivity of existing hydrogen-free deoxygenation catalysts, the present invention provides a bimetallic hydrogen-free deoxygenation catalyst and a preparation method thereof, and application in the hydrogen-free deoxygenation of bio-oil to bio-aviation fuel. The present invention uses aminosilane (-NH2) (i.e., aminopropyltriethoxysilane) to prepare a silicon-based mesoporous surface functionalized carrier SBA-15-NH2, which effectively increases the pore size and specific surface area of ​​the carrier. This modification helps the metal particles to disperse on the surface and pores of the carrier, and increases the dispersion of Ni and Co bimetallics on the surface and pores of the silicon-based carrier as much as possible, while increasing the acid sites and active sites of the catalyst, thereby improving the catalytic efficiency and selectivity of the catalyst, solving the problem that the current catalyst is difficult to meet the needs of industrial production and conversion of bio-aviation fuel.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] One of the technical solutions of the present invention is a method for preparing a bimetallic hydrogen-free deoxygenation catalyst, comprising the following steps:

[0006] Step 1, mixing a template solution and a buffer to obtain a buffered template solution;

[0007] Adding a silicon source and aminopropyltriethoxysilane to the buffered template solution, stirring, heating for reaction, and then filtering, and washing, refluxing, filtering, washing, and drying the obtained solid in sequence to obtain a surface-functionalized SBA-15-NH2 carrier;

[0008] Step 2, dispersing the surface functionalized SBA-15-NH2 carrier in an ethanol solution, then adding cobalt salt and nickel salt and stirring, filtering the obtained solid, washing, drying and then calcining to obtain the bimetallic hydrogen-free deoxygenation catalyst.

[0009] The second technical solution of the present invention is a bimetallic hydrogen-free deoxygenation catalyst prepared according to the above-mentioned preparation method.

[0010] A third technical solution of the present invention is an application of the above-mentioned bimetallic hydrogen-free deoxygenation catalyst in the hydrogen-free deoxygenation of bio-oil to convert it into bio-aviation fuel.

[0011] A fourth technical solution of the present invention is a method for preparing bio-aviation fuel by hydrogen-free deoxygenation conversion of bio-oil, which comprises mixing bio-oil with the above-mentioned bimetallic hydrogen-free deoxygenation catalyst, and heating the mixture under an inert atmosphere to obtain bio-aviation fuel.

[0012] The present invention discloses the following technical effects:

[0013] (1) The present invention adopts aminosilane surface functionalization technology to increase the pore size and specific surface area of ​​the silicon-based mesoporous carrier and increase the anchoring sites of metal particles.

[0014] (2) Compared with the existing bimetallic hydrogen-free deoxygenation catalyst, the metal particles of the present invention have better dispersibility on the carrier surface.

[0015] (3) Due to the greater dispersion of metal particles on the carrier surface and the introduction of amino and silane groups, the acid sites and active sites of the catalyst are greatly increased, and the catalyst activity and selectivity are greatly improved.

[0016] (4) The introduction of amino groups leads to stronger electrostatic attraction on the carrier surface, and the adsorption stability of metal particles on the carrier surface is enhanced. The service life of the catalyst is extended from 3 times to 6 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The conversion yield data and conversion selectivity data of the catalyst prepared in Example 1 and Comparative Example 1 when used for the hydrogen-free deoxygenation of bio-oil to bio-aviation fuel; wherein, the left figure is the conversion yield data, and the right figure is the conversion selectivity data.

[0019] Figure 2 High-resolution electron microscope analysis images of the catalysts prepared in Example 1 and Comparative Example 1, wherein the left image is Comparative Example 1 and the right image is Example 1.

[0020] Figure 3 Schematic diagram of the device for preparing bio-aviation fuel by hydrogen-free deoxygenation conversion of bio-oil. DETAILED DESCRIPTION

[0021] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0022] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0023] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0024] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0025] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0026] The present invention discloses a Ni-Co / SBA-15-NH2 hydrogen-free deoxygenation catalyst with surface functionalized mesoporous silicon-based material loaded with Ni-Co. The bimetallic hydrogen-free deoxygenation catalyst has the characteristics of low manufacturing cost, high catalytic conversion efficiency, strong jet fuel hydrocarbon selectivity, etc., and is very suitable for the needs of bio-oil conversion to bio-aviation fuel hydrocarbons. Once the catalyst is promoted and used, it will effectively improve the production efficiency of bio-oil, especially the industrial conversion of waste edible oil to green bio-jet fuel, reduce production costs, and thus produce good environmental, social and economic benefits.

[0027] The present invention uses surface functionalized silicon-based mesoporous material SBA-15-NH2 as a carrier and adopts a wet impregnation method to load Ni and Co bimetallic particles to prepare a bimetallic hydrogen-free deoxygenation catalyst. The preparation method of the bimetallic hydrogen-free deoxygenation catalyst comprises the following steps:

[0028] Step 1, mixing a template solution and a buffer to obtain a buffered template solution;

[0029] Adding a silicon source and aminopropyltriethoxysilane to the buffered template solution, stirring, heating for reaction, and then filtering, and washing, refluxing, filtering, washing, and drying the obtained solid in sequence to obtain a surface-functionalized SBA-15-NH2 carrier;

[0030] Step 2, dispersing the surface functionalized SBA-15-NH2 carrier in an ethanol solution, then adding cobalt salt and nickel salt and stirring, filtering the obtained solid, washing, drying and then calcining to obtain the bimetallic hydrogen-free deoxygenation catalyst.

[0031] In a preferred embodiment of the present invention, in step 1, the concentration of the template solution is 0.13-0.15 g / mL; the template is poloxamer; the buffer is a hydrochloric acid solution with a concentration of 2.0 M; and the mixing temperature is 40°C.

[0032] In a preferred embodiment of the present invention, in step 1, the silicon source is ethyl orthosilicate; the molecular formula of the aminopropyltriethoxysilane is NH 2- CH2CH2CH2Si(OC2H5)3; the mass volume ratio of the silicon source to the aminopropyltriethoxysilane is 8.5g:0.7mL; the volume ratio of the aminopropyltriethoxysilane to the buffer template solution is 0.4:150.

[0033] In a preferred embodiment of the present invention, in step 1, the stirring temperature is 40°C and the stirring time is 24 hours; the heating reaction temperature is 80°C and the time is 24 hours; the reflux temperature is 80°C and the time is 24 hours; the drying temperature is 60°C and the time is 8-12 hours.

[0034] In a preferred embodiment of the present invention, in step 2, the volume concentration of the ethanol solution is 95%; the mass volume ratio of the surface functionalized SBA-15-NH2 carrier to the ethanol solution is 1g:40mL; the cobalt salt is Co(NO3)2·6H2; and the nickel salt is Ni(NO3)2·6H2O.

[0035] In a specific embodiment of the present invention, the cobalt salt and the nickel salt are added in the form of a solution. When the cobalt salt and the nickel salt are prepared into a solution, the amount of solvent water is not particularly limited, and the amount of solvent water can fully dissolve the cobalt salt and the nickel salt. The amount of cobalt salt added is 5% of the mass of the surface functionalized SBA-15-NH2 carrier; the amount of nickel salt added is 5% of the mass of the surface functionalized SBA-15-NH2 carrier.

[0036] In a preferred embodiment of the present invention, in step 2, the stirring temperature is 80°C and the time is 3 hours; the drying temperature is 80°C and the time is 8-12 hours; and the calcination temperature is 550°C and the time is 5 hours.

[0037] The present invention also provides a bimetallic hydrogen-free deoxidation catalyst prepared according to the preparation method.

[0038] The present invention also provides the use of the bimetallic hydrogen-free deoxygenation catalyst in the hydrogen-free deoxygenation of bio-oil to convert bio-aviation fuel.

[0039] The present invention also provides a method for preparing bio-aviation fuel by hydrogen-free deoxygenation conversion of bio-oil, wherein the bio-oil is mixed with a bimetallic hydrogen-free deoxygenation catalyst, and heated to react under an inert atmosphere to obtain the bio-aviation fuel.

[0040] In a preferred embodiment of the present invention, the mass ratio of the bio-fat to the bimetallic hydrogen-free deoxygenation catalyst is 10:1; the temperature of the heating reaction is 270° C.-330° C., and the time is 60-360 minutes.

[0041] (1) The present invention uses SBA-15 silicon-based mesoporous material as a modified carrier matrix to ensure that metal particles such as Ni and Co can be effectively dispersed on the carrier surface and in the pores. (2) In the process of carrier preparation, aminosilane is used to perform surface functionalization treatment on the mesoporous silicon-based material. Due to the introduction of amino and silane functional groups (infrared spectrum, XRD and electron microscopy data show that amino and silane functional groups are successfully introduced), the mesoporous silicon-based material has larger pores and specific surface area in the micelle formation stage. At the same time, the presence of silane functional groups provides more anchor points for the loading of metal particles, which are conducive to the dispersion of metal particles on the carrier surface and in the pores, reducing the agglomeration of metal particles. The presence of amino groups also provides stronger electrostatic attraction, promotes the electrostatic adsorption and stabilization of metal particles, and increases the loading amount of metal particles. (3) The introduction of aminosilane functional groups provides more acidic sites and active sites for the catalyst, which is conducive to the enhancement of catalyst activity and selectivity. (4) The technical design principle of the catalyst is to use aminosilane to introduce amino and silane functional groups during the preparation of the catalyst carrier for surface functionalization, thereby increasing the pore size of the carrier and introducing amino and silane groups at the same time, so that the loading of metal particles on the carrier surface and in the pores is more uniform in the later stage, and the loading amount and loading stability are enhanced. At the same time, due to the increase in the distribution of silane groups and metal particles on the carrier surface, its acidic sites and active sites are greatly increased, thereby improving the conversion efficiency and selectivity of the catalyst.

[0042] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0043] The ethanol solution used in the embodiment of the present invention is an ethanol aqueous solution with a volume concentration of 95%.

[0044] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0045] Example 1

[0046] 4 g of poloxamer (Pluronic P123) was dissolved in 30 ml of distilled water, and then 120 ml of hydrochloric acid (2.0 M) solution was added and heated at 40°C until a transparent solution was formed. Then 8.5 g of tetraethyl orthosilicate (TEOS) and 0.7 ml of aminosilane (-NH2) were added to the mixture and stirred at 40°C for 24 hours. After that, it was placed in an oven at 80°C for 24 hours. The sample obtained by filtration was then washed with ethanol and refluxed at 80°C for 24 hours. The sample was filtered, washed with ethanol, and dried in an oven at 60°C overnight to obtain a surface-functionalized SBA-15-NH2 carrier. The specific surface area of ​​the surface-functionalized SBA-15-NH2 carrier was 588.82 m 2 .g -1 , pore volume is 0.91m 3 .g -1 .

[0047] The bimetallic hydrogen-free deoxygenation catalyst was prepared by wet impregnation, as follows: 2 g of SBA-15-NH2 carrier was dispersed in 80 ml of ethanol solution, and then the required volume of Co(NO3)2·6H2O and Ni(NO3)2·6H2O solution was added and stirred at room temperature for about 3 hours, and slowly heated to form a uniform compound at 80°C. Finally, the generated solid was filtered, washed with distilled water, dried in an oven at 80°C overnight, and finally calcined at 550°C for 5 hours to obtain a 5Ni5Co / SBA-15-NH2 bimetallic hydrogen-free deoxygenation catalyst (Ni and Co loadings on the surface functionalized SBA-15-NH2 carrier were 5 wt%, respectively).

[0048] Comparative Example 1

[0049] 4 g of Pluronic P123 was dissolved in 30 ml of distilled water, and then 120 ml of hydrochloric acid (2.0 M) solution was added and heated at 40°C until a transparent solution was formed. Then 8.5 g of TEOS was added to the mixture and stirred at 40°C for 24 hours. It was placed in an oven at 80°C for 24 hours. The sample was then filtered, washed with ethanol, and refluxed at 80°C for 24 hours. The sample was filtered, washed with ethanol, and dried in an oven at 60°C overnight to obtain an SBA-15 carrier with a specific surface area of ​​406 m 2 .g -1 , pore volume is 0.41m 3 .g -1 .

[0050] 2 g of SBA-15 carrier was dispersed in 80 ml of ethanol solution, and then the required volume of Co(NO3)2·6H2O and Ni(NO3)2·6H2O solution was added and stirred at room temperature for about 3 hours, and slowly heated to form a uniform compound at 80°C. Finally, the generated solid was filtered, washed with distilled water, dried in an oven at 80°C overnight, and finally calcined at 550°C for 5 hours to obtain a 5Ni5Co / SBA-15 bimetallic hydrogen-free deoxygenation catalyst, with Ni and Co loadings on the SBA-15 carrier of 5 wt %. (That is, the only difference from Example 1 is that the addition of 0.7 ml of aminosilane (-NH2) is omitted, and the remaining steps and parameters are the same as Example 1)

[0051] The performance of the 5Ni5Co / SBA-15-NH2 (abbreviated as NiCo / SBA-15-NH2) prepared in Example 1 of the present invention and the 5Ni5Co / SBA-15 (abbreviated as NiCo / SBA-15) catalyst in Comparative Example 1 was compared:

[0052] (1) Method for converting bio-oil into bio-jet fuel hydrocarbon compounds:

[0053] Bio-oils were converted into bio-jet fuel hydrocarbons by solvent-free deoxygenation reaction in the presence of N2. Figure 3 The preparation of a deoxygenation catalytic reaction is described. The deoxygenation reaction was carried out in a semi-batch reactor with loading for 360 min at different temperatures (270°C-330°C). During the treatment, 10.0 g of bio-lipid and 1.0 g of catalyst were placed in the reactor, nitrogen was passed through the reactor for 30 min to ensure that the reaction was carried out under inert conditions, and the air in the reactor was evacuated. Then, the reaction mixture was heated at a certain temperature (270°C-330°C) for 360 min and stirred at 80 rpm. The condenser temperature was kept constant below 17°C by external water cooling. A blank experiment was carried out in order to compare the deoxygenation process in the absence of catalyst.

[0054] (2) Analysis of the composition of reaction product compounds

[0055] The liquid obtained from the deoxygenation process was analyzed by a gas chromatography-FID system. 20 ) was used to obtain a standard curve for determining the composition of the liquid product, while 1-bromohexane was used as an internal standard. Prior to analysis, the biojet fuel product was diluted with n-hexane (chromatographic grade) and 1 μL of the sample was injected into the GC column. The deoxygenated product was compared with standard hydrocarbons (C8-C 20) retention time, and the performance of the catalyst in terms of hydrocarbon yield and hydrocarbon selectivity was evaluated using a gas chromatography detection system. The calculation formula is as follows:

[0056] Hydrocarbon production percentage (%) = (total hydrocarbons (C8-C 20 ) / total amount of product)×100%(1)

[0057] Biojet fuel selectivity (%) = (biojet fuel amount (C8-C 16 ) / total hydrocarbons (C8-C 20 ))×100%(2)

[0058] Figure 1 The left figure shows the conversion yield data, and the right figure shows the conversion selectivity data. Figure 1 It can be seen that the hydrocarbon conversion yield of the catalyst NiCo / SBA-15-NH2 in Example 1 reaches more than 95% (blue column), while the hydrocarbon yield of the catalyst NiCo / SBA-15 in Comparative Example 1 is only about 60% (red column), and the gray column in the figure is the conversion yield without catalyst; and the jet fuel selectivity (the total number of hydrocarbons in the C8-C17 range) of the catalyst NiCo / SBA-15-NH2 in Example 1 is also higher than that of the catalyst NiCo / SBA-15 in Comparative Example 1, reaching more than 88%, while the catalyst NiCo / SBA-15 in Comparative Example 1 is about 80%.

[0059] Figure 2 The high-resolution electron microscope analysis pictures of the catalysts prepared in Example 1 and Comparative Example 1 are shown in FIG. 1 , wherein the left picture is Comparative Example 1 and the right picture is Example 1. Figure 2 It can be seen that the metal particles in the catalyst prepared in Example 1 are more evenly dispersed than those in the catalyst prepared in Comparative Example 1.

[0060] The present invention also verifies the stability of repeated use of the catalysts prepared in Example 1 and Comparative Example 1. The results show that the reuse rate of NiCo / SBA-15 is up to 3 times, and the conversion efficiency decreases by 25% and the selectivity decreases by 30% when used for the third time. The reuse rate of NiCo / SBA-15-NH2 reaches 6 times, and the conversion rate decreases by only 15% and the selectivity decreases by only 20% when used for the sixth time.

[0061] The catalyst of the present invention adopts surface functionalization means and creatively utilizes aminosilane (-NH2) to modify the traditional silicon-based mesoporous material SBA-15 to prepare a surface functionalized carrier SBA-15-NH2, so as to increase the dispersion of Ni and Co metal particles on the surface and in the pores of the silicon-based carrier, and obtain a Ni-Co / SBA-15-NH2 bimetallic hydrogen-free deoxygenation catalyst. The catalyst has higher hydrogen-free deoxygenation conversion activity and bio-jet fuel component conversion selectivity, and can better solve the problem of low activity and poor selectivity of previous hydrogen-free deoxygenation conversion bimetallic catalysts.

[0062] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a bimetallic hydrogen-free deoxygenation catalyst, characterized in that: The following steps are involved: Step 1, mixing a template solution and a buffer to obtain a buffered template solution; Adding a silicon source and aminopropyltriethoxysilane to the buffered template solution, stirring, heating for reaction, and then filtering, and washing, refluxing, filtering, washing, and drying the obtained solid in sequence to obtain a surface-functionalized SBA-15-NH2 carrier; Step 2, dispersing the surface functionalized SBA-15-NH2 carrier in an ethanol solution, then adding cobalt salt and nickel salt and stirring, filtering the obtained solid, washing, drying and then calcining to obtain the bimetallic hydrogen-free deoxygenation catalyst.

2. The method for preparing the bimetallic hydrogen-free deoxygenation catalyst according to claim 1, characterized in that: In step 1, the concentration of the template solution is 0.13-0.15 g / mL; the template is poloxamer; the buffer is a 2.0 M hydrochloric acid solution; and the mixing temperature is 40°C.

3. The method for preparing the bimetallic hydrogen-free deoxygenation catalyst according to claim 1, characterized in that: In step 1, the silicon source is ethyl orthosilicate; the mass volume ratio of the silicon source to the aminopropyltriethoxysilane is 8.5 g:0.7 mL; the volume ratio of the aminopropyltriethoxysilane to the buffer template solution is 0.4:

150.

4. The method for preparing the bimetallic hydrogen-free deoxygenation catalyst according to claim 1, characterized in that: In step 1, the stirring temperature is 40°C and the stirring time is 24 hours; the heating reaction temperature is 80°C and the time is 24 hours; the reflux temperature is 80°C and the time is 24 hours; the drying temperature is 60°C and the time is 8-12 hours.

5. The method for preparing the bimetallic hydrogen-free deoxygenation catalyst according to claim 1, characterized in that: In step 2, the volume concentration of the ethanol solution is 95%; the mass volume ratio of the surface functionalized SBA-15-NH2 carrier to the ethanol solution is 1g:40mL; the cobalt salt is Co(NO3)2·6H2; the nickel salt is Ni(NO3)2·6H2O; the amount of cobalt salt added is 5% of the mass of the surface functionalized SBA-15-NH2 carrier; the amount of nickel salt added is 5% of the mass of the surface functionalized SBA-15-NH2 carrier.

6. The method for preparing a bimetallic hydrogen-free deoxygenation catalyst according to claim 1, characterized in that: In step 2, the stirring temperature is 80° C. and the time is 3 hours; the drying temperature is 80° C. and the time is 8-12 hours; and the calcination temperature is 550° C. and the time is 5 hours.

7. A bimetallic hydrogen-free deoxygenation catalyst prepared according to the preparation method according to any one of claims 1 to 6.

8. Use of the bimetallic hydrogen-free deoxygenation catalyst as claimed in claim 7 in the hydrogen-free deoxygenation of bio-oil to convert it into bio-aviation fuel.

9. A method for preparing bio-aviation fuel by hydrogen-free deoxygenation conversion of bio-oil, characterized in that: The bio-oil is mixed with the bimetallic hydrogen-free deoxidation catalyst as claimed in claim 8, and heated to react under an inert atmosphere to obtain bio-aviation fuel.

10. The method according to claim 9, characterized in that The mass ratio of the bio-grease to the bimetallic hydrogen-free deoxygenation catalyst is 10:1; the temperature of the heating reaction is 270° C.-330° C., and the time is 60-360 minutes.

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