Preparation method and application of a hydrodeoxygenation bifunctional NiNb-based catalyst

Abstract

The application is a preparation method and application of a hydrogen-deoxidation bifunctional NiNb-based catalyst. The method uses an optimized sol-gel method to prepare silica doped with niobium species as a carrier, and an equal-impregnation method is used to load a nickel-containing precursor on the composite carrier doped with a niobium additive. Only a nickel source, a niobium source, a complexing agent and a silicon source are needed, without other initiators, promoters and solubilizers, which can reduce the interference of impurities, reduce the cost and simplify the process. The content of oxygen vacancies in the doped catalyst obtained by the application is significantly improved, which greatly promotes the deoxidation effect and effectively makes up for the problem of insufficient deoxidation capacity of the existing catalyst mentioned in the background art, and has very strong advantages and significant applicability in the lignin-derived phenol HDO system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lignin derivative hydrodeoxygenation, and in particular to a preparation method of a nickel supported catalyst with niobium doped silicon dioxide as a carrier, and to the field of preparing naphthene fuel by hydrodeoxygenation of lignin derivative model compounds. BACKGROUND

[0002] Lignin is a high molecular material with huge reserves and stable output, which widely exists in the cells of lignified plants, and is regenerated at a speed of about 50 billion tons per year, and has great potential for utilization. Only the global pulp and paper industry can obtain about 70 million tons of lignin by-products from plants every year, but more than 95% of the lignin is discharged into rivers in the form of "black liquor" or burned after concentration, and the utilization rate is very low. Lignin-derived monomers and dimers are mainly phenolic and ether compounds, which can be hydrodeoxygenated (HDO) to obtain hydrocarbons with carbon number distribution between 6-10, which is basically consistent with the carbon number distribution of commercial gasoline components, and is an ideal green biofuel (CN 110066677A). Therefore, it is particularly important to find a simple and efficient catalyst for depolymerizing lignin to obtain liquid fuel, which is of great significance for the efficient utilization of lignin.

[0003] From the composition of the catalyst, the HDO of phenolic compounds requires a bifunctional catalyst, which involves hydrogenation on the metal site and dehydration / deoxygenation on the carrier.

[0004] Non-noble metal catalysts have attracted extensive attention due to their significant economic advantages. Although non-noble metal catalysts exhibit good hydrogenation or oxygenation performance, they are still inferior to noble metal catalysts. Compared with other transition metals, Ni has a wider d-electron band and higher energy density, which can greatly improve the adsorption and activation of hydrogen molecules, thus providing more active hydrogen species for hydrogenation reactions (Green Chemistry, 2020, 22(23), 8140-8168; Green Chemistry, 2016, 18, 5845-5858). Among Ni, Fe, Cu, Zn, Sn and other transition metal catalysts, Ni-based catalysts exhibit the best activity and product selectivity for the production of renewable chemicals and fuels from lignin. Most of the existing Ni-based catalysts can achieve a conversion rate of more than 85% for typical lignin derivatives such as guaiacol, but the average selectivity of the main product cyclohexane is less than 75%, and there are many oxygen-containing by-products such as phenol and cyclohexanol. Because the dissociation energy of the hydroxyl group is very high, it is generally believed that 300℃ is necessary to achieve high HDO efficiency in non-noble metal systems, and some reaction temperatures even need to be as high as 400℃, indicating that deoxygenation is the key to this type of reaction. Generally, researchers will prepare bimetallic or bifunctional catalyst systems containing non-noble metals to maximize their performance advantages. Therefore, it is necessary to introduce a second metal or other additives to better play the role of deoxygenation, and it is also necessary to develop catalysts with excellent performance under milder reaction conditions.

[0005] Nb compounds have played a significant role in promoting various types of catalytic reactions such as hydrogenation deoxygenation, hydrogenation desulfurization, ammonia oxidation, and solid acid reactions, and can be used as additives or carriers to enhance reaction activity. Patent CN114870853B uses a combination of template method and impregnation method to introduce Nb metal modification during shell formation, forming functional Co@Nb-WO x MSiO2YSNSs catalysts for the hydrogenation of guaiacol to prepare cyclohexanol, and found that the additives Nb and WO xThe introduction of Nb2O5 improves the catalytic activity of metal Co, the dispersion of metal and the acid sites of the catalyst. When Nb2O5 is used as a single carrier, there are problems such as too small specific surface area and too large acidity (Catal. Today, 2017, 285, 211-225). Doping Nb species into the network of other oxides helps to adjust the acidity, thermal stability and specific surface area of the original carrier, and further improves its performance by introducing lattice defects. Fernandes et al. (JTAC, 2017, 131(1), 691-5) incorporated Nb into MCM-41 nanostructured materials and verified the changes in the surface properties and acid functions of the materials. Patent CN 107812516 B provides a preparation method of Nb2O5-doped CeO2, its product and application. When noble metals are loaded, it shows good benzene combustion performance, but polyvinyl alcohol needs to be added as a solubilizing agent to avoid the precipitation of cerium ions due to the addition of oxalate ions during the preparation process. Patent CN 105939775 A uses an impregnation method to prepare cerium oxide catalysts doped with niobium oxide or tantalum oxide, which is applied to selective catalytic reduction reactions, but due to the low solubility of niobium salt, the impregnation method often has the disadvantage of uneven particle distribution when preparing niobium-doped compounds. The closest to the present invention are the following two technologies: Patent CN 113680347 A modifies the cheap SiO2 carrier by adding soluble precursors of Ce, Ta and Nb to prepare a catalyst for oil hydrodesulfurization and regulation of aromatic ring saturation; Patent CN 113441139 A prepares a Nb2O5-SiO2 catalyst loaded with Pd, Pt and Ni, which is used to catalyze the hydrodeoxygenation reaction of sugar platform compound condensates to produce liquid alkanes. However, during the impregnation process, the carrier needs to be immersed in the impregnation solution for a long time (CN 113441139 A), and too high a drying temperature leads to uneven dispersion of the active phase and also causes a loss of 1-3wt% of the active metal components (CN 113680347 A), resulting in a large difference between the actual metal loading and the theoretical loading, making it difficult to control the amount of precursor and increasing the cost of catalyst preparation. In addition, the specific surface area and pore volume of the carrier are not improved enough during the doping process, and the overall catalytic performance needs to be improved.

[0006] The methods used for doping transition metal oxides are mostly traditional methods, such as impregnation, which leads to uneven dispersion of the active phase and loss of active metals; co-precipitation requires long stirring time and introduces alkaline substances, and also requires filtration and washing; hydrothermal method often requires high temperature and pressure, and the preparation time is also relatively long. Sol-gel method has the advantages of short preparation time, simple operation, no need for filtration and washing, and less loss of catalyst components. However, the sol-gel method still needs to be optimized, for example, by controlling the heating rate to adjust the crystal crystallization, while the temperature and time of cross-linking and drying will affect the grain growth and further affect the micro-morphology of the product. SUMMARY

[0007] The purpose of the present application is to provide a preparation method and application of a hydrodeoxygenation bifunctional NiNb-based catalyst to address the deficiencies of the current catalyst. The method uses an optimized sol-gel method to prepare silica doped with niobium species as the carrier, and an equal amount of impregnation method to load the nickel-containing precursor on the composite carrier doped with niobium additives. Only nickel source, niobium source, complexing agent and silicon source are required, without other initiators, accelerators and solubilizers, which can reduce the interference of impurities, reduce costs and simplify the process. The use of complexing agents can help form metal ion complexes, control the concentration of metal ions, and also help adjust the pH value of the reaction system, thereby promoting the formation of gels and improving the quality of gels, increasing the specific surface area and pore volume of the catalyst. The content of oxygen vacancies in the doped catalyst obtained by the present application is significantly improved, which greatly promotes the deoxygenation effect and effectively addresses the problem of insufficient deoxygenation capacity of the existing catalysts mentioned in the background art, and has very strong advantages and significant applicability in the lignin-derived phenol HDO system.

[0008] The technical solution of the present application is:

[0009] A preparation method of a hydrodeoxygenation bifunctional NiNb-based catalyst, the method comprising the following steps:

[0010] (1) Add a silicon source to deionized water, magnetically stir for 5-30 min, then add a complexing agent, continue to magnetically stir for 5-30 min, and obtain solution A;

[0011] Wherein, the mass ratio of the added components is silicon source: complexing agent: deionized water = 1:0.1-0.5:4-12;

[0012] (2) Add a niobium source to the solution A obtained in step (1) under stirring, continue to magnetically stir for 2-8 h, and obtain homogeneous hydrogel pre-polymer liquid B;

[0013] Wherein, the mass ratio is niobium source: silicon source = 1:1-21;

[0014] (3) Segmentally dry the hydrogel pre-polymer liquid B obtained in step (2), the first stage is constant temperature drying at 40-60℃ for 4-6h, take out and grind; continue constant temperature drying at 40-60℃ for 4-6h, and obtain dried solid;

[0015] (4) Calcine the dried solid obtained in step (3) in a muffle furnace at 400-600℃ for 3-5h, with a heating rate of 1-5℃ / min, and obtain yNb@Si sample, which is a silica composite oxide carrier doped with niobium species;

[0016] wherein y represents the doping amount of niobium species in the carrier, and is 4-45wt%;

[0017] (5) The saturated water absorption of the composite oxide carrier obtained in step (4) is determined, and then a nickel source solution is added to the carrier by an equal-amount impregnation method;

[0018] (6) The sample obtained in step (5) is dried at 30-40℃ for 10-12h;

[0019] (7) The dried sample in step (6) is calcined in a muffle furnace at 400-600℃ for 3-5h;

[0020] (8) The calcined sample in step (7) is reduced in a tubular furnace in a flowing hydrogen atmosphere at 400-600℃ for 3-5h to obtain an xNi / yNb@Si catalyst, i.e., a hydrodeoxygenation bifunctional NiNb-based catalyst.

[0021] Optionally, the silicon source in step (1) is one or more of tetraethyl orthosilicate, tetramethyl orthosilicate, tetra-n-butyl orthosilicate, tetra-isopropyl orthosilicate, and alkylalkoxysilane;

[0022] Optionally, the complexing agent in step (1) includes one or more of citric acid, tartaric acid, ethylenediaminetetraacetic acid, malic acid, glycolic acid, and succinic acid;

[0023] Optionally, the niobium source in step (2) includes one or more of niobium oxalate, niobium pentachloride, ethyl niobium, niobium acetate, ammonium niobium oxalate hydrate, or niobium hydroxide;

[0024] Optionally, the nickel source in step (5) includes one or more of nickel nitrate, nickel chloride, nickel carbonate, and nickel oxalate; the concentration of the nickel source solution is 1-4mol / L.

[0025] Further, the hydrodeoxygenation bifunctional NiNb-based catalyst is characterized in that, due to strong metal-carrier interaction during catalyst formation, nickel niobate is formed on the nickel-niobium interface, and special crystalline niobium oxide is formed in the carrier, which can act as an acidic site and is conducive to the removal of oxygen-containing functional groups.

[0026] The doping amount of the Nb additive in the composite carrier is 4-45wt% in terms of mass percentage, and the content of the Ni active component on the catalyst is 1-10wt%.

[0027] The application of the hydrodeoxygenation bifunctional NiNb-based catalyst prepared by the method is used as a catalyst in a process for preparing naphthenic fuel by hydrodeoxygenation of lignin derivatives.

[0028] The specific steps are as follows:

[0029] The lignin derivative, n-dodecane and the hydrogenation and deoxidation bifunctional NiNb-based catalyst are added into a reaction kettle, the kettle is sealed, gas replacement is carried out in the kettle by using 0.5-2 MPa argon, and the reaction is carried out under the conditions of 3-7 MPa hydrogen pressure, 200-260 DEG C and stirring for 0.5-10 h, so that cycloalkanes are obtained;

[0030] The mass ratio of the catalyst, the reactant and the solvent is 1:5-100:490-2400, preferably, the mass ratio of the catalyst and the reactant is 1:10;

[0031] The lignin derivative is one or more of common representative lignin derivative phenolic substances, including phenol, m-cresol, p-cresol, guaiacol, 2-methoxy-4-propylphenol, eugenol and 2,6-dimethoxyphenol, and one or more of lignin derivative dimer substances containing β-O-4, α-O-4 and 4-O-5 bonds.

[0032] Preferably, the reaction temperature is 250 DEG C, the reaction pressure is preferably 5 MPa, the reaction time is preferably 2 h, and the loading amount of the metal in the xNi / yNb@Si catalyst is preferably 10 wt% Ni and 20 wt% Nb.

[0033] The cycloalkane is one or more of cyclohexane, methylcyclohexane, ethylcyclohexane, propylcyclohexane, methylcyclopentane and methylcyclobutane.

[0034] The substantial features of the present application are:

[0035] The present application adopts a sol-gel method to dope niobium oxide into the SiO2 network and impregnate an equivalent amount of nickel precursor to prepare a stable Ni / Nb@Si catalyst system, and the system is applied to the field of preparing cycloalkane fuel by hydrogenation and deoxidation of lignin derivative phenolic compounds. When the niobium source is introduced during the hydrolysis and gelation of the silicon source, Nb enters the SiO2 framework, generates Nb-O bonds to partially replace Si-O bonds, changes the unit cell parameters and the unit cell stacking mode of the composite carrier, and greatly increases the specific surface area of the carrier material. At the same time, due to the difference in atomic size between niobium and silicon, the crystal structure is easily deformed during grain growth, lattice defects are introduced, the carrier acidity is changed, and a large number of oxygen vacancies are generated. Further, when the Nb content is too high, Nb is difficult to completely enter the SiO2 framework, and independent Nb2O5 crystal phases are generated, which reduces the specific surface area and oxygen vacancies to a certain extent. Preferably, the niobium doping amount is 5-20 wt%.

[0036] Compared with the prior art, the present application has the following beneficial effects:

[0037] (1) The composite oxide carrier in the application is obtained by a sol-gel method, which makes up for the shortcomings of a single carrier, increases the specific surface area of the catalyst, improves the dispersity of the active metal nickel, and improves the performance of the catalyst through the synergistic effect of the metal sites and the carrier. From the change of the specific surface area, the Nb2O5 is 6 m 2 / g, the SiO2 is 636 m 2 / g, and the 5Nb@Si after doping increases to 811 m 2 / g, which is 311-511 m 2 / g higher than the preferred specific surface area of the Nb2O5-SiO2 composite oxide in patent CN 113441139 A. From the reaction results of examples 6-12, after loading Ni on only silicon dioxide or niobium pentoxide as a carrier, the selectivity of catalytic guaiacol hydrogenation deoxygenation to cyclohexane is less than 20%; while the selectivity of cyclohexane after loading Ni on the niobium-silicon composite carrier is all greater than 55%, which has been significantly improved, and the highest can even reach 94.37%, and the conversion rate of the reactant can reach 100%.

[0038] (2) The catalyst in the application can realize efficient conversion of lignin derivatives under relatively mild conditions and selectively generate cycloalkane substances. The calculated apparent activation energy of the HDO reaction on the 10Ni / 20Nb@Si catalyst is 54.23 kJ·mol -1 , which is better than the best result reported on non-noble metal catalysts, i.e. 55.9 kJ·mol -1 (Fuel, 2022, 308, 122034). The obtained catalyst has a significant effect on common lignin derivatives hydrogenation deoxygenation and strong universality, and has good application prospect.

[0039] (3) In the application, the catalyst preparation cycle is short, and the process flow is simple; the prices of the raw materials and catalysts used are low, which can significantly reduce the cost; transition metals such as nickel (the price as of July 12, 2024 is 133.375 yuan / kg) and niobium (the price as of July 12, 2024 is 670 yuan / kg) are more economical than noble metals such as platinum (the price as of July 12, 2024 is 212060 yuan / kg) and palladium (the price as of July 12, 2024 is 262000 yuan / kg). In addition, the impact of nickel metal on global warming is estimated to be about 6.5 kg CO2 equivalent / kg, while the impact of platinum metal is 12,500 kg CO2 equivalent / kg, so the components and raw materials selected in the application are more economical and environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1The XRD patterns of the different catalysts obtained in Examples 1-5 and Comparative Example 1 after reduction under H2 atmosphere are shown.

[0041] Figure 2 The N2 physisorption-desorption characterization results are shown for different catalysts obtained in Examples 1-5 and Comparative Example 1; wherein, Figure 2 (a) is the N2 physical adsorption-desorption isotherm; Figure 2 (b) is a diagram showing the aperture distribution.

[0042] Figure 3 For different supports and catalysts obtained in Examples 2-4 and Comparative Example 1 Characteristic peaks of acids and Lewis acids.

[0043] Figure 4 The O1s and Ni2p values ​​of the catalysts obtained in Examples 2-4 and Comparative Examples 1-2 3 / 2 XPS spectra of Nb3d and Nb3d, where O α O represents the characteristic peaks associated with lattice oxygen. β The characteristic peak represents vacant oxygen associated with oxygen vacancies. Detailed Implementation

[0044] The present invention will now be described through specific embodiments. Unless otherwise specified, all technical means used in the present invention are methods well known to those skilled in the art. Furthermore, the embodiments should be understood as illustrative, not limiting the scope of the invention; the essence and scope of the invention are defined only by the claims. Experimental methods not specifically described in the embodiments generally use conventional conditions and conditions described in manuals, or conditions recommended by the manufacturer. Common equipment, materials, reagents, etc., are commercially available unless otherwise specified. The present invention will be further described below with reference to specific embodiments.

[0045] Catalyst preparation methods:

[0046] Example 1

[0047] Silicon source 12.38 g tetraethyl orthosilicate (TEOS) was added to 49.54 g deionized water, and after magnetic stirring for 10 min, complexing agent 3.84 g citric acid (CA) was added, and magnetic stirring was continued for 10 min, then niobium source 0.7604 g niobium oxalate was added to the solution, and magnetic stirring was continued for 6 h to obtain a homogeneous hydrogel pre-polymer solution. The obtained hydrogel pre-polymer solution was subjected to stepwise drying, the first stage was constant temperature drying at 50℃ for 4 h to make the hydrogel cross-linked and shaped, until no liquid was present in the container, and the pre-polymer solution became a shaped jelly-like solid, which was then taken out and ground into small particles with a mortar; the second stage was constant temperature drying at 50℃ for 5 h to remove internal water and all other volatile substances. Then the dried solid was calcined in a muffle furnace at 600℃ (heating rate 2℃ / min) for 3 h to obtain a composite oxide carrier with a Nb doping amount of about 5wt%, which was recorded as 5Nb@Si sample. According to the saturated water absorption amount of the 5Nb@Si carrier, 2.2015 g of Ni(NO3)2·6H2O was weighed and dissolved in 2.80 g deionized water to obtain a nickel source solution by ultrasonic dispersion for 30 min, and an equal volume of the nickel source solution was added to 4.0 g of the 5Nb@Si carrier by dropwise impregnation method. Then it was dried at 30℃ for 12 h, calcined at 500℃ (heating rate 5℃ / min) for 3 h, and reduced at 500℃ (heating rate 5℃ / min) for 3 h in a tube furnace under a flowing hydrogen atmosphere of 80 mL / min to obtain a 10Ni / 5Nb@Si catalyst (10Ni represents that the active metal Ni loaded accounts for 10wt% of the total mass of the catalyst, and 5Nb represents that the doping amount of niobium species in the carrier is 5wt%).

[0048] Example 2

[0049] Silicon source 12.38 g tetraethyl orthosilicate (TEOS) was added to 49.54 g deionized water, and after magnetic stirring for 10 min, complexing agent 3.84 g citric acid (CA) was added, and magnetic stirring was continued for 10 min, then niobium source 1.6053 g niobium oxalate was added to the solution, and magnetic stirring was continued for 6 h to obtain a homogeneous hydrogel pre-polymer solution. The obtained hydrogel pre-polymer solution was subjected to the same stepwise drying process as in Example 1, and then the dried solid was calcined in a muffle furnace at 600℃ (heating rate 2℃ / min) for 3 h to obtain a composite carrier with a Nb doping amount of about 10wt%, which was recorded as 10Nb@Si sample. The loading method of the nickel source was the same as in Example 1 to obtain a 10Ni / 10Nb@Si catalyst.

[0050] Example 3

[0051] Silicon source 12.38 g tetraethyl orthosilicate (TEOS) was added to 49.54 g deionized water, and after magnetic stirring for 10 min, complexing agent 3.84 g citric acid (CA) was added, and magnetic stirring was continued for 10 min. Then niobium source 3.6119 g niobium oxalate was added to the solution, and magnetic stirring was continued for 6 h to obtain a homogeneous hydrogel pre-polymer solution. The obtained hydrogel pre-polymer solution was subjected to the same stepwise drying treatment as in Example 1, and then the dried solid was calcined at 600 °C (heating rate 2 °C / min) in a muffle furnace for 3 h to obtain a composite carrier with a Nb doping amount of about 5 wt%, which was recorded as 20Nb@Si sample. The loading method of the nickel source was the same as in Example 1 to obtain a 10Ni / 20Nb@Si catalyst.

[0052] Example 4

[0053] Silicon source 12.38 g tetraethyl orthosilicate (TEOS) was added to 49.54 g deionized water, and after magnetic stirring for 10 min, complexing agent 3.84 g citric acid (CA) was added, and magnetic stirring was continued for 10 min. Then niobium source 6.1919 g niobium oxalate was added to the solution, and magnetic stirring was continued for 6 h to obtain a homogeneous hydrogel pre-polymer solution. The obtained hydrogel pre-polymer solution was subjected to the same stepwise drying treatment as in Example 1, and then the dried solid was calcined at 600 °C (heating rate 2 °C / min) in a muffle furnace for 3 h to obtain a composite carrier with a Nb doping amount of about 5 wt%, which was recorded as 30Nb@Si sample. The loading method of the nickel source was the same as in Example 1 to obtain a 10Ni / 30Nb@Si catalyst.

[0054] Example 5

[0055] Silicon source 12.38 g tetraethyl orthosilicate (TEOS) was added to 49.54 g deionized water, and after magnetic stirring for 10 min, complexing agent 3.84 g citric acid (CA) was added, and magnetic stirring was continued for 10 min. Then niobium source 9.6317 g niobium oxalate was added to the solution, and magnetic stirring was continued for 6 h to obtain a homogeneous hydrogel pre-polymer solution. The obtained hydrogel pre-polymer solution was subjected to the same stepwise drying treatment as in Example 1, and then the dried solid was calcined at 600 °C (heating rate 2 °C / min) in a muffle furnace for 3 h to obtain a composite carrier with a Nb doping amount of about 5 wt%, which was recorded as 40Nb@Si sample. The loading method of the nickel source was the same as in Example 1 to obtain a 10Ni / 40Nb@Si catalyst.

[0056] Comparative Example 1

[0057] Using the same sol-gel method as in Example 1, without adding niobium oxalate, a SiO2 alone was synthesized, and then 10 wt% Ni was loaded to obtain a 10Ni / SiO2 catalyst.

[0058] Comparative Example 2

[0059] The same sol-gel method as in Example 1 was used to synthesize Nb2O5 alone without adding tetraethyl orthosilicate, and then 10wt% of Ni was loaded to obtain the 10Ni / Nb2O5 catalyst.

[0060] From the XRD results of Figure 1 As the Nb content increased, the diffraction peaks of amorphous TT-niobium pentoxide appeared, and the diffraction peaks at 2θ of 44.5, 51.8 and 76.4° belonged to the Ni (111), (200) and (220) planes (PDF #87-0712), respectively, indicating the formation of FCC (face-centered cubic) Ni phase.

[0061] From the XRD results of Figure 2 It can be seen from the results that the prepared catalysts have similar pore size distribution and pore structure, with the most probable pore size of 3-4 nm. The specific surface area of Nb2O5 is only 6m 2 / g, but after doping niobium oxide into the silica network, the specific surface area of the 5Nb@Si support increases to 811m 2 / g, when the Nb doping amount is too high, it is difficult for Nb to completely enter the SiO2 framework, and independent Nb2O5 crystal phase is generated, and the specific surface area of 40Nb@Si decreases to 226m 2 / g, therefore the doping amount of niobium has a key influence on the structure.

[0062] Comparative Example 3

[0063] The other steps are the same as in Example 1, except that the obtained hydrogel pre-polymer solution is not subjected to staged drying, but is directly continuously dried at 50°C for 10h. After continuous drying, the final dried solid will become a large hard solid in the form of broken glass, which is difficult to grind into small particles or powder, resulting in poor and incomplete calcination of the subsequent calcination, and the organic matter inside the large solid is difficult to convert and release, which adversely affects the performance of the catalyst.

[0064] The inventors have explored a staged drying method through experiments. The first stage of drying causes chemical reactions inside the catalyst to occur, forming doping and cross-linking between different species, and the catalyst gradually changes from a solution to a sol and then to a gel. When there is no liquid in the container and the pre-polymer solution becomes a shaped jelly-like solid, it is taken out of the oven and ground into small particles using a mortar. Then the second stage of drying is performed until complete drying (4-6h), so that more uniform and complete calcination can be achieved.

[0065] Table 1 Specific surface area and pore structure information of different samples

[0066]

[0067] In Figure 3 the peaks at 1449, 1490 and 1616 cm -1 correspond to the adsorption of pyridine on the Lewis acid sites of the catalyst, and the peak at 1540 cm -1 corresponds to the adsorption of pyridine on the acid sites, and the results confirm that the Lewis acid sites are dominant in the acid sites on the surface of the catalyst, which is mainly due to the presence of coordination unsaturated Ni, Nb cations.

[0068] In Figure 4 the O1s spectrum can be decomposed into a characteristic peak (O α ) at 530.4 eV related to lattice oxygen in the sample, and a characteristic peak (O β ) at 532.5 eV related to vacancy oxygen associated with oxygen defects. In the 10Ni / SiO2 and 10Ni / Nb2O5 catalysts, O α O β ; while in the Ni / Nb@Si sample, O α O β , indicating that there are more oxygen vacancies in the sample after doping niobium.

[0069] The catalyst obtained by the application comprises an active component, a metal promoter and a carrier, and can realize dual functions of hydrogenation and deoxygenation; wherein the nickel species is the hydrogenation active component, and the doped niobium species is the deoxygenation active component. The catalyst can be applied to the reaction of preparing naphthenes from lignin derivatives by hydrogenation and deoxygenation, and the following is a specific example.

[0070] Example 6

[0071] The materials were fed into a 100 mL high-pressure mechanical stirred tank, and the mass ratio of the materials was catalyst: reactant: solvent = 1:10:490. In this example, the catalyst used was the catalyst 10Ni / SiO2 obtained in Comparative Example 1, and the mass was 0.05 g. The reactant was guaiacol, and the solvent was n-dodecane. The reaction tank was assembled and the air tightness of the device was checked, then argon was filled from the reaction inlet, and the gas in the tank was replaced for several times until the air content was negligible. The condensate water was opened, the mechanical stirring was started to a certain speed (generally 800 r / min), the temperature program was set and the temperature was started to rise. 5 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at a temperature of 250℃ for 2 h. The conversion rate and selectivity data of the related species were calculated and are shown in Table 2.

[0072] Example 7

[0073] The 100 mL high-pressure mechanical stirred tank was charged with catalyst, reactant and solvent in a mass ratio of 1 : 10: 490. In this example, the catalyst 10Ni / 5Nb@Si obtained in Example 1 was selected, with a mass of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The pre-treatment and reaction conditions were the same as in Example 6. The conversion and selectivity data of the relevant species were calculated and are shown in Table 2.

[0074] Example 8

[0075] The 100 mL high-pressure mechanical stirred tank was charged with catalyst, reactant and solvent in a mass ratio of 1 : 10: 490. In this example, the catalyst 10Ni / 5Nb@Si obtained in Example 1 was selected, with a mass of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The pre-treatment and reaction conditions were the same as in Example 6. The conversion and selectivity data of the relevant species were calculated and are shown in Table 2.

[0076] Example 9

[0077] The 100 mL high-pressure mechanical stirred tank was charged with catalyst, reactant and solvent in a mass ratio of 1 : 10: 490. In this example, the catalyst 10Ni / 5Nb@Si obtained in Example 1 was selected, with a mass of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The pre-treatment and reaction conditions were the same as in Example 6. The conversion and selectivity data of the relevant species were calculated and are shown in Table 2.

[0078] Example 10

[0079] The 100 mL high-pressure mechanical stirred tank was charged with catalyst, reactant and solvent in a mass ratio of 1 : 10: 490. In this example, the catalyst 10Ni / 5Nb@Si obtained in Example 1 was selected, with a mass of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The pre-treatment and reaction conditions were the same as in Example 6. The conversion and selectivity data of the relevant species were calculated and are shown in Table 2.

[0080] Example 11

[0081] The 100 mL high-pressure mechanical stirred tank was charged with catalyst, reactant and solvent in a mass ratio of 1 : 10: 490. In this example, the catalyst 10Ni / 5Nb@Si obtained in Example 1 was selected, with a mass of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The pre-treatment and reaction conditions were the same as in Example 6. The conversion and selectivity data of the relevant species were calculated and are shown in Table 2.

[0082] Example 12

[0083] The catalyst, reactant and solvent were fed into a 100 mL high-pressure mechanical stirred tank reactor in a mass ratio of catalyst: reactant: solvent = 1:10:490. In this example, the catalyst 10Ni / Nb2O5 obtained in Comparative Example 2 was selected, and the mass of the catalyst was 0.05 g. The reactant was guaiacol, and the solvent was n-dodecane. The reaction was pre-processed and the reaction conditions were the same as in Example 6. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 2.

[0084] As can be seen from the results of different proportions, the selectivity of naphthenes of the pure Ni / SiO2 catalyst is too low, and the product is mainly an oxygen-containing product, indicating that the deoxygenation capacity of the catalyst is not enough. After the introduction of Nb, the naphthenes yield is improved. The catalytic effect shows a trend of first increasing and then decreasing with the increase of the content of Nb, and the catalytic activity is the highest when the content of Nb is 20wt%, which can make the conversion rate of guaiacol reach 100% and the selectivity of cyclohexane reach 94.37%. It is shown that an appropriate amount of Nb content is beneficial to the improvement of the selectivity of deoxygenated products.

[0085] Table 2 Reaction results of Examples 6-12

[0086]

[0087] In order to compare the effects of different reaction temperatures on the guaiacol hydrogenation and deoxygenation reaction, the catalyst 10Ni / 20Nb@Si was selected as the further research object, and the following Examples 13-19 were carried out.

[0088] Example 13

[0089] The catalyst, reactant and solvent were fed into a 100 mL high-pressure mechanical stirred tank reactor in a mass ratio of catalyst: reactant: solvent = 1:10:490. In this example, the catalyst 10Ni / 20Nb@Si obtained in Example 3 was used, and the mass of the catalyst was 0.05 g. The reactant was guaiacol, and the solvent was n-dodecane. The reaction kettle was assembled and the air tightness of the device was checked, then argon was filled from the reaction inlet, and the gas in the kettle was replaced for many times until the air content was negligible. The condensate water was opened, the mechanical stirring was opened to a certain speed, the temperature rising program was set and the temperature rising was started. 5 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at a temperature of 200°C for 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 3.

[0090] Example 14

[0091] The catalyst, reactant and solvent were fed into a 100 mL high-pressure mechanical stirred tank reactor in a mass ratio of catalyst: reactant: solvent = 1:10:490. In this example, the catalyst 10Ni / 20Nb@Si obtained in Example 3 was used, and the mass of the catalyst was 0.05 g. The reactant was guaiacol, and the solvent was n-dodecane. The reaction kettle was assembled and the air tightness of the device was checked, then argon was filled from the reaction inlet, and the gas in the kettle was replaced for many times until the air content was negligible. The condensate water was opened, the mechanical stirring was opened to a certain speed, the temperature rising program was set and the temperature rising was started. 5 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at a temperature of 200°C for 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 3.

[0092] Example 15

[0093] The same catalyst and reaction feed as in Example 13 were charged into a 100 mL high-pressure mechanical stirred tank reactor. The reaction was carried out at 230 °C for 2 h with 5 MPa hydrogen as the hydrogen source. The conversion and selectivity data of the relevant species were calculated and are shown in Table 3.

[0094] Example 16

[0095] The same catalyst and reaction feed as in Example 13 were charged into a 100 mL high-pressure mechanical stirred tank reactor. The reaction was carried out at 230 °C for 2 h with 5 MPa hydrogen as the hydrogen source. The conversion and selectivity data of the relevant species were calculated and are shown in Table 3.

[0096] Example 17

[0097] The same catalyst and reaction feed as in Example 13 were charged into a 100 mL high-pressure mechanical stirred tank reactor. The reaction was carried out at 240 °C for 2 h with 5 MPa hydrogen as the hydrogen source. The conversion and selectivity data of the relevant species were calculated and are shown in Table 3.

[0098] Example 18

[0099] The same catalyst and reaction feed as in Example 13 were charged into a 100 mL high-pressure mechanical stirred tank reactor. The reaction was carried out at 250 °C for 2 h with 5 MPa hydrogen as the hydrogen source. The conversion and selectivity data of the relevant species were calculated and are shown in Table 3.

[0100] Example 19

[0101] The same catalyst and reaction feed as in Example 13 were charged into a 100 mL high-pressure mechanical stirred tank reactor. The reaction was carried out at 260 °C for 2 h with 5 MPa hydrogen as the hydrogen source. The conversion and selectivity data of the relevant species were calculated and are shown in Table 3.

[0102] Table 3 Reaction results of catalyst HDO at different temperatures

[0103]

[0104] In terms of temperature, at a lower reaction temperature, the selectivity of naphthenes is not high enough, and the proportion of cycloalcohols and cycloethers is large, indicating that the hydroxyl and methoxyl groups cannot be effectively removed at a low temperature. As the reaction temperature increases, the rate of removal of hydroxyl and methoxyl groups gradually increases, resulting in an increase in the amount of cyclohexane generated. At 250 °C, the yield of naphthene products reaches 100%. The selectivity increases abruptly, which may be because the temperature has exceeded the energy required for the Calkyl-OH bond to break, causing the alcohol product to rapidly remove the hydroxyl group to generate naphthenes. After further increasing the reaction temperature, there is no obvious change in the distribution of the products.

[0105] To further compare the effect of different reaction pressures on the guaiacol hydrogenation-deoxidation reaction, experiments were performed as follows in Examples 20-24.

[0106] Example 20

[0107] The catalyst, reactant, and solvent were fed into a 100 mL high-pressure mechanical stirred tank reactor in a mass ratio of 1:10:490. In this example, the catalyst 10Ni / 20Nb@Si obtained in Example 3 was used in an amount of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The reactor was assembled and the air tightness of the device was checked, then argon was charged from the reaction inlet, and the gas in the tank was replaced multiple times until the air content was negligible. The cooling water was turned on, the mechanical stirring was turned on to a certain speed, the temperature program was set, and the temperature was started to be raised. 2 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at a temperature of 250°C for 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 4.

[0108] Example 21

[0109] The catalyst, reactant, and solvent were fed into a 100 mL high-pressure mechanical stirred tank reactor in a mass ratio of 1:10:490. In this example, the catalyst 10Ni / 20Nb@Si obtained in Example 3 was used in an amount of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The reactor was assembled and the air tightness of the device was checked, then argon was charged from the reaction inlet, and the gas in the tank was replaced multiple times until the air content was negligible. The cooling water was turned on, the mechanical stirring was turned on to a certain speed, the temperature program was set, and the temperature was started to be raised. 2 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at a temperature of 250°C for 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 4.

[0110] Example 22

[0111] The catalyst, reactant, and solvent were fed into a 100 mL high-pressure mechanical stirred tank reactor in a mass ratio of 1:10:490. In this example, the catalyst 10Ni / 20Nb@Si obtained in Example 3 was used in an amount of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The reactor was assembled and the air tightness of the device was checked, then argon was charged from the reaction inlet, and the gas in the tank was replaced multiple times until the air content was negligible. The cooling water was turned on, the mechanical stirring was turned on to a certain speed, the temperature program was set, and the temperature was started to be raised. 2 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at a temperature of 250°C for 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 4.

[0112] Example 23

[0113] The catalyst, reactant, and solvent were fed into a 100 mL high-pressure mechanical stirred tank reactor in a mass ratio of 1:10:490. In this example, the catalyst 10Ni / 20Nb@Si obtained in Example 3 was used in an amount of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The reactor was assembled and the air tightness of the device was checked, then argon was charged from the reaction inlet, and the gas in the tank was replaced multiple times until the air content was negligible. The cooling water was turned on, the mechanical stirring was turned on to a certain speed, the temperature program was set, and the temperature was started to be raised. 2 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at a temperature of 250°C for 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 4.

[0114] Example 24

[0115] The catalyst, reactant, and solvent were fed into a 100 mL high-pressure mechanical stirred tank reactor in a mass ratio of 1:10:490. In this example, the catalyst 10Ni / 20Nb@Si obtained in Example 3 was used in an amount of 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The reactor was assembled and the air tightness of the device was checked, then argon was charged from the reaction inlet, and the gas in the tank was replaced multiple times until the air content was negligible. The cooling water was turned on, the mechanical stirring was turned on to a certain speed, the temperature program was set, and the temperature was started to be raised. 2 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at a temperature of 250°C for 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 4.

[0116] Table 4 Reaction results of catalyst HDO at different pressures

[0117]

[0118] The effect of the reaction H2 pressure on the product distribution is mainly reflected in the content change of the unsaturated products. Under relatively low pressure conditions, there is a certain amount of benzene and 1,2-dimethoxybenzene, indicating that the hydrogen source is insufficient and the benzene ring is difficult to achieve hydrogenation saturation, so the hydrogen partial pressure should be increased. With the continuous increase of the reaction pressure, the selectivity of naphthene reaches a peak at 5 MPa, but it slightly decreases at 6 MPa, which is mainly because under high hydrogen pressure conditions, a part of naphthene generates methylcyclopentane due to the hydrogenolysis of C-C bond.

[0119] In order to further compare the effects of different reaction times on the guaiacol hydrogenation deoxygenation reaction, the following Examples 25-29 were carried out.

[0120] Example 25

[0121] The catalyst, reactant and solvent were fed into a 100 mL high-pressure mechanical stirred tank in a mass ratio of 1:10:490. In this example, the mass of the catalyst 10Ni / 20Nb@Si obtained in Example 3 was 0.05 g, the reactant was guaiacol, and the solvent was n-dodecane. The assembly of the reaction tank was carried out and the air tightness of the device was checked, then argon was filled from the reaction inlet, and the gas in the tank was replaced for several times until the air content was negligible. The cooling water was opened, the mechanical stirring was opened to a certain speed, the temperature program was set and the temperature rising was started. 5 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at 250°C for 0.5 h. The conversion rate and selectivity data of the related species were calculated and shown in Table 5.

[0122] Example 26

[0123] The catalyst and reactant were fed into a 100 mL high-pressure mechanical stirred tank. The amount of the catalyst and the reactant was the same as that in Example 25. 5 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at 250°C for 1 h. The conversion rate and selectivity data of the related species were calculated and shown in Table 5.

[0124] Example 27

[0125] The catalyst and reactant were fed into a 100 mL high-pressure mechanical stirred tank. The amount of the catalyst and the reactant was the same as that in Example 25. 5 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at 250°C for 2 h. The conversion rate and selectivity data of the related species were calculated and shown in Table 5.

[0126] Example 28

[0127] The catalyst and reactant were fed into a 100 mL high-pressure mechanical stirred tank. The amount of the catalyst and the reactant was the same as that in Example 25. 5 MPa hydrogen was used as the hydrogen source, and the reaction was carried out at 250°C for 4 h. The conversion rate and selectivity data of the related species were calculated and shown in Table 5.

[0128] Example 29

[0129] The catalyst and the reaction material were put into a 100 mL high-pressure mechanical stirred tank. The amount of catalyst and reaction material used was the same as in Example 25. The reaction was carried out at a temperature of 250°C for 6 h with 5 MPa hydrogen as the hydrogen source. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 5.

[0130] Table 5 Reaction results of catalyst HDO at different reaction times

[0131]

[0132] The change rule of the reaction with time (0.5-6 h) can be seen that guaiacol is completely converted after 1 h of reaction, indicating that the catalyst 10Ni / 20Nb@Si has high catalytic efficiency and can quickly achieve hydrogenation saturation of the aromatic ring and effective removal of part of the oxygen-containing functional groups. When the time is extended to 2 h, the yield of the target product tends to be stable. However, when the time is further extended, it is found that the cycloalkane product begins to gradually decrease, which is also due to the ring-closing reaction of some branched cyclopentane and cyclobutane. In summary, the optimal reaction conditions are 250°C, 5 MPa, and 2 h.

[0133] To explore the universality of the catalyst 10Ni / 20Nb@Si, it was applied to HDO experiments of other representative lignin-derived monomers and dimers. In order to study the effect of different substituents on the aromatic ring on HDO, phenol, m-cresol, p-cresol, 2-methoxy-4-propylphenol were selected as representative model compounds. To further increase the unsaturation of the reactant, eugenol was used as the reactant. In order to study the influence of the presence of more oxygen-containing functional groups in the reactant, 2,6-dimethoxyphenol and 4-phenoxyphenol were used as the reactants. The specific implementation is as follows.

[0134] Example 30

[0135] The catalyst 10Ni / 20Nb@Si obtained in Example 3 was used for the hydrodeoxygenation reaction of phenol. N-dodecane 24.5 g, reactant 4 mmol (mass 0.3760 g), catalyst 0.05 g were put into the reaction kettle. The pre-treatment conditions were the same as in Example 25, the temperature was raised to 250°C, the hydrogen pressure in the kettle was maintained at 5 MPa, and the reaction time was 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 6.

[0136] Example 31

[0137] The obtained catalyst 10Ni / 20Nb@Si was used for the hydrodeoxygenation reaction of m-cresol. n-Dodecane 24.5 g, reactant 4 mmol (mass 0.4326 g), catalyst 0.05 g were put into the reaction kettle. The pretreatment conditions before reaction were the same as in Example 25, the temperature was raised to 250 ℃, the hydrogen pressure in the kettle was kept at 5 MPa, and the reaction time was 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 6.

[0138] Example 32

[0139] The obtained catalyst 10Ni / 20Nb@Si was used for the hydrodeoxygenation reaction of p-cresol. n-Dodecane 24.5 g, reactant 4 mmol (mass 0.4326 g), catalyst 0.05 g were put into the reaction kettle. The pretreatment conditions before reaction were the same as in Example 25, the temperature was raised to 250 ℃, the hydrogen pressure in the kettle was kept at 5 MPa, and the reaction time was 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 6.

[0140] Example 33

[0141] The obtained catalyst 10Ni / 20Nb@Si was used for the hydrodeoxygenation reaction of guaiacol. n-Dodecane 24.5 g, reactant 4 mmol (mass 0.4966 g), catalyst 0.05 g were put into the reaction kettle. The pretreatment conditions before reaction were the same as in Example 25, the temperature was raised to 250 ℃, the hydrogen pressure in the kettle was kept at 5 MPa, and the reaction time was 2 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 6.

[0142] Example 34

[0143] The obtained catalyst 10Ni / 20Nb@Si was used for the hydrodeoxygenation reaction of 2-methoxy-4-propylphenol. n-Dodecane 24.5 g, reactant 4 mmol (mass 0.6649 g), catalyst 0.05 g were put into the reaction kettle. The pretreatment conditions before reaction were the same as in Example 25, the temperature was raised to 250 ℃, the hydrogen pressure in the kettle was kept at 5 MPa, and the reaction time was 10 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 6.

[0144] Example 35

[0145] The obtained catalyst 10Ni / 20Nb@Si was used for the hydrodeoxygenation reaction of eugenol. n-Dodecane 24.5 g, reactant 4 mmol (mass 0.6568 g), catalyst 0.05 g were put into the reaction kettle. The pretreatment conditions before reaction were the same as in Example 25, the temperature was raised to 250 ℃, the hydrogen pressure in the kettle was kept at 5 MPa, and the reaction time was 10 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 6.

[0146] Example 36

[0147] The obtained catalyst 10Ni / 20Nb@Si was used for the hydrodeoxygenation reaction of 2,6-dimethoxyphenol. N-dodecane 24.5 g, phenol 4 mmol (mass 0.6167 g), catalyst 0.05 g were put into the reaction kettle. The pretreatment conditions before reaction were the same as in Example 25, the temperature was raised to 250°C, the hydrogen pressure in the kettle was kept at 5 MPa, and the reaction time was 10 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 6.

[0148] Example 37

[0149] The obtained catalyst 10Ni / 20Nb@Si was used for the hydrodeoxygenation reaction of 4-phenoxyphenol. N-dodecane 24.5 g, reactant 4 mmol (mass 0.7448 g), catalyst 0.05 g were put into the reaction kettle. The pretreatment conditions before reaction were the same as in Example 25, the temperature was raised to 250°C, the hydrogen pressure in the kettle was kept at 5 MPa, and the reaction time was 10 h. The conversion rate and selectivity data of the relevant species were calculated and are shown in Table 6.

[0150] Table 6 Reaction results of Examples 30-37

[0151]

[0152]

[0153] The above detailed description of the present application is made with specific examples. Obviously, the described examples are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0154] The details of the present application not described above are known technologies.

Claims

1. The application of a bifunctional NiNb-based hydrodeoxygenation catalyst in the process of preparing cycloalkane fuels by hydrodeoxygenation of lignin derivatives, characterized in that, Includes the following steps: A lignin derivative, n-dodecane, and a bifunctional NiNb-based catalyst for hydrodeoxygenation were added to a reactor. After sealing, the reactor was purged with 0.5-2 MPa argon gas. The reactor was then reacted for 0.5-10 h under conditions of 3-7 MPa hydrogen pressure, 200-260 °C, and stirring to obtain cycloalkanes. The mass ratio of the feed materials is catalyst:reactant:solvent = 1:5-100:490-2400; The lignin derivative is one or more of lignin-derived phenolic substances and lignin-derived dimers; The preparation method of the aforementioned hydrodeoxygenation bifunctional NiNb-based catalyst includes the following steps: (1) Add the silicon source to deionized water, stir magnetically for 5-30 minutes, then add the complexing agent and continue stirring magnetically for 5-30 minutes to obtain solution A; The added components are in the following mass ratio: silicon source: complexing agent: deionized water = 1:0.1-0.5:4-12; (2) Add the niobium source to the solution A obtained in step (1) under stirring, and continue to stir magnetically for 2-8 hours to obtain a homogeneous hydrogel prepolymer solution B; (3) The hydrogel prepolymer B obtained in step (2) is dried in stages. In the first stage, it is dried at a constant temperature of 40-60℃ for 4-6 hours, then taken out and ground. Then, it is dried at a constant temperature of 40-60℃ for another 4-6 hours to obtain a dried solid. (4) The dried solid obtained in step (3) is calcined at 400-600℃ for 3-5 hours with a heating rate of 1-5℃ / min to obtain a silica composite oxide support doped with niobium species; wherein the doping amount of niobium species in the support is 5-20 wt%; (5) Determine the saturated water absorption of the composite oxide support obtained in step (4), and then use the equal volume impregnation method to drop the nickel source solution onto the support; (6) Dry the sample obtained in step (5) at 30-40℃ for 10-12 hours; (7) Calcine the dried sample from step (6) at 400-600℃ for 3-5 hours; (8) The sample calcined in step (7) is reduced in a tube furnace in a flowing hydrogen atmosphere at 400-600 °C for 3-5 h to obtain xNi / yNb@Si catalyst, i.e., hydrogenation and deoxygenation bifunctional NiNb-based catalyst. The silicon source mentioned in step (1) is one or more of tetraethyl orthosilicate, methyl orthosilicate, butyl orthosilicate, isopropyl orthosilicate, and alkylalkoxysilane; The complexing agent mentioned in step (1) includes one or more of citric acid, tartaric acid, malic acid and succinic acid; The niobium source mentioned in step (2) includes one or more of niobium oxalate, niobium pentachloride, niobium ethoxylate, and ammonium oxalate hydrate of niobate; The nickel source mentioned in step (5) includes one or both of nickel nitrate and nickel chloride; the concentration of the nickel source solution is 1-4 mol / L.

2. The application of the bifunctional NiNb-based hydrodeoxygenation catalyst as described in claim 1 in the process of preparing cycloalkane fuels by hydrodeoxygenation of lignin derivatives, characterized in that, The lignin derivatives are one or more of phenol, m-cresol, p-cresol, guaiacol, 2-methoxy-4-propylphenol, eugenol, 2,6-dimethoxyphenol, and lignin-derived dimers containing β-O-4, α-O-4, or 4-O-5 bonds.

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