Ni-nb-p non-supported catalyst, preparation method and application thereof

Abstract

The application provides a Ni-Nb-P non-supported catalyst, the catalyst comprises Ni3P and NbOPO4, the catalyst has a mesoporous structure by nitrogen adsorption and desorption method testing, and the catalyst has a sheet structure by SEM testing.The catalyst is prepared by the steps of mixing, stirring, crystallization, drying, calcination and reduction of a soluble nickel salt, a soluble niobium salt, a template agent and diammonium hydrogen phosphate.The application also provides application of the Ni-Nb-P non-supported catalyst in hydrodeoxygenation of oxygen-containing compounds in bio-oil.The preparation process of the Ni-Nb-P non-supported catalyst provided by the application has mild reaction conditions, the template method combined with the one-pot method for preparing the catalyst has the characteristics of high efficiency, and the preparation efficiency of the catalyst can be greatly improved.The Ni-Nb-P catalyst prepared by the application can realize efficient deoxygenation of oxygen-containing bio-oil to prepare liquid alkane fuel oil, and has the excellent effects of high activity and high deoxygenation rate.

Description

Technical Field

[0001] This invention belongs to the field of catalysis technology, specifically relating to a Ni-Nb-P unsupported catalyst, its preparation method, and its application. Background Technology

[0002] In recent years, with the increasing severity of energy and environmental problems, countries around the world are vying to develop safe and environmentally friendly renewable energy sources. Among the many renewable energy sources, biomass energy is abundant, widely available, inexpensive, and readily available, meeting the requirements of sustainable development. Currently, a large amount of research is dedicated to converting biomass into fuels and high-value-added products, especially the research on producing fuels from woody biomass through hydrodeoxygenation, which has received widespread attention.

[0003] Lignin is the most abundant renewable aromatic polymer in nature and the only non-petroleum resource providing renewable aryl compounds. Lignin and its model compounds are applied to lignin degradation through various methods, including hydrogenolysis, oxidation, hydrolysis, thermal, photochemical, and electrochemical approaches. Among these, hydrogenolysis of lignin is one of the most promising pathways, characterized by good product selectivity, high calorific value, high overall atom economy, and high lignin conversion rate. The reaction typically requires a catalyst that simultaneously provides acidic sites and redox activity to achieve high activity and high selectivity. Catalytic hydrogenation degradation of lignin mainly utilizes heterogeneous catalysts, either precious metals or non-precious metals.

[0004] Non-precious metal catalysts are mainly based on Cu, Fe, and Ni. Among them, Ni catalysts exhibit excellent selectivity in the cleavage of CO bonds in aryl ethers, but nickel catalysts have limited activity and stability and are prone to deactivation. Currently, most common hydrodeoxygenation catalysts are transition metal supported catalysts, but their activity is difficult to improve due to the limitation of the active component loading by the support, resulting in harsh reaction conditions. Unsupported catalysts are classified into sulfide, oxidized, and phosphide catalysts according to their morphology. Preparation methods typically include solid-state reaction, co-precipitation, sol-gel method, and hydrothermal synthesis, but these methods are inefficient and produce catalysts with low activity and selectivity.

[0005] Therefore, developing a highly efficient, unsupported catalyst with high activity and selectivity for hydrodeoxygenation is an urgent technical problem to be solved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this application provides a Ni-Nb-P unsupported catalyst and a method for preparing Ni-Nb-P unsupported catalysts using a template method combined with a one-pot method. The template method combined with the one-pot method of this application is highly efficient, significantly improving catalyst preparation efficiency. Furthermore, the multi-cluster catalyst synthesized by the template method combined with the one-pot method exhibits high activity and selectivity, demonstrating excellent performance in catalytic reactions.

[0007] The Ni-Nb-P unsupported catalyst provided by the present invention comprises Ni3P and NbOPO4. The catalyst exhibits a mesoporous structure as determined by nitrogen adsorption-desorption testing and a plate-like structure as determined by SEM testing.

[0008] This invention also provides a method for preparing the Ni-Nb-P unsupported catalyst as described above. The catalyst is prepared by mixing, stirring, crystallizing, drying, calcining, and reducing a soluble nickel salt, a soluble niobium salt, a template agent, and diammonium hydrogen phosphate. Specifically, the method includes the following steps:

[0009] Step SS1: Weigh out a certain amount of niobium oxalate hydrate, nickel nitrate, hexadecyltrimethylammonium bromide, and diammonium hydrogen phosphate and dissolve them separately in beakers containing 10ml to 20ml of deionized water for later use;

[0010] Step SS2: Adjust the pH of the diammonium hydrogen phosphate solution to 2-6 using 85% phosphoric acid;

[0011] Step SS3: Under magnetic stirring at a speed of 200-300 r / min, the niobium oxalate solution prepared in step SS1 is added dropwise to the beaker of the diammonium hydrogen phosphate solution that has been adjusted to pH. After stirring for 10 min, solution A is obtained. Then, nickel nitrate solution is added dropwise to solution A and stirred for 30 min to obtain solution B.

[0012] Step SS4: Add the solution B prepared in step SS3 to the CTAB solution to obtain emulsion C;

[0013] Step SS5: Place the emulsion C in a thermostat and stir at a constant temperature for 3-5 hours to obtain the treated emulsion C;

[0014] Step SS6: Transfer the emulsion C after step SS5 to a crystallization vessel, crystallize at 150-160℃ for 18-24h, filter and wash the filtered solid, and then place the solid in a constant temperature drying oven at 80-120℃ for 4-10h to obtain the Ni-Nb-P composite oxide precursor.

[0015] Step SS7: Calcine the Ni-Nb-P composite oxide precursor in a muffle furnace at 450-550℃ for 3-5 hours, and then reduce it with hydrogen in a tube furnace at 400-500℃ for 3-5 hours to obtain a bulk Ni-Nb-P catalyst.

[0016] Furthermore, in step SS1, the molar ratio of niobium oxalate hydrate to nickel nitrate is between 0.5 and 3.0, the amount of CTAB added is equal to 0.5 to 2 times the total molar amount of niobium oxalate hydrate and nickel nitrate, and the amount of diammonium hydrogen phosphate added is 1.0 to 2.5 times the total molar amount of niobium oxalate hydrate and nickel nitrate.

[0017] Furthermore, in step SS3, the dropping rate of the niobium oxalate solution and the nickel nitrate solution is 60–120 drops / min.

[0018] Furthermore, in step SS4, the flow rate of adding solution B to the CTAB solution is 60–120 drops / min.

[0019] Furthermore, in step SS5, the thermostat temperature is 30–40°C, and the stirring speed is 700 r / min.

[0020] Furthermore, in step SS6, the filtration and solid washing are carried out under a vacuum of -0.05 to -0.07 MPa. The filtered solid is then washed with distilled water, using 400-500 mL of distilled water each time, for 3-5 washes.

[0021] Furthermore, the hydrogen flow rate in the hydrogen reduction process in step SS7 is 30-50 mL / min.

[0022] This invention also provides an application of the Ni-Nb-P unsupported catalyst described above in the hydrodeoxygenation of oxygen-containing compounds in bio-oil. The Ni-Nb-P catalyst and bio-oil are placed in a batch reactor, with the mass ratio of bio-oil to catalyst being 5:1 to 20:1. The hydrodeoxygenation reaction is carried out for 10 min to 6 h under the conditions of hydrogen pressure 1 MPa to 4 MPa, temperature 80 to 200 °C, and stirring speed 500 to 800 r / min, to obtain the hydrodeoxygenated product.

[0023] Furthermore, 10–20 ml of dodecane was added to the batch reactor.

[0024] Compared with the prior art, the superior effects of the present invention are:

[0025] 1. The Ni-Nb-P unsupported catalyst formulation and preparation process provided by this invention have mild reaction conditions. The template method combined with the "one-pot method" for catalyst preparation in this application has the characteristics of high efficiency, which can greatly improve the preparation efficiency of the catalyst.

[0026] 2. When the Ni-Nb-P catalyst prepared in this invention is applied to the hydrodeoxygenation of oxygen-containing compounds in bio-oil, it can achieve efficient deoxygenation of oxygen-containing bio-oil to produce liquid alkane fuel oil, exhibiting excellent effects of high activity and high deoxygenation rate.

[0027] 3. This invention uses a template method combined with a one-pot method to prepare unsupported bifunctional catalysts. This method combines metallic Ni3P and acidic NbOPO4. By controlling the synthesis conditions, it achieves uniform distribution and interaction of active and acidic components, resulting in high activity and high selectivity.

[0028] 4. Compared with supported hydrodeoxygenation catalysts, the catalyst prepared in this invention does not use a support, and all components have catalytic activity. It is mainly composed of medium-strong acid and strong acid sites, with L acid as the main acid center. This provides more active centers for the lignin-derived hydrodeoxygenation reaction and has a stronger hydrodeoxygenation capacity.

[0029] 5. This invention selects a nickel-phosphorus component combined with mesoporous niobium phosphate, and the Ni3P active component combined with the acidic sites of NbOPO4, which makes the hydrodeoxygenation activity higher, the catalytic effect better, and has the advantages of low-cost Ni metal and synergistic effect in hydrogenation activity of lignin, resulting in a high deoxygenation rate for hydrodeoxygenation of lignin-derived oxygen-containing compounds. Attached Figure Description

[0030] Figure 1 The image shows the XRD pattern of the unsupported bifunctional Ni-Nb-P catalyst prepared in Example 1.

[0031] Figure 2 The images show the N2 adsorption-desorption isotherm (a) and pore size distribution (b) of the unsupported bifunctional Ni-Nb-P catalyst prepared in Example 1.

[0032] Figure 3 This is a SEM image of the unsupported bifunctional Ni-Nb-P catalyst prepared in Example 1;

[0033] Figure 4 The image shows the infrared spectrum of the unsupported bifunctional Ni-Nb-P catalyst pyridine prepared in Example 1. Detailed Implementation

[0034] The present invention will be further described below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0035] The technical solution of the present invention will be further explained below with reference to implementation examples.

[0036] Example 1: Preparation of bifunctional Ni-Nb-P catalyst

[0037] Step SS1: Weigh 1.08g of niobium oxalate hydrate, 0.87g of nickel nitrate, and 0.528g of diammonium hydrogen phosphate (NHHPO) and dissolve them in 10ml of water respectively; dissolve 0.73g of hexadecyltrimethylammonium bromide (CTAB) in 20ml of water.

[0038] Step SS2: Adjust the pH of the diammonium hydrogen phosphate solution to 2 using 85% phosphoric acid;

[0039] Step SS3: Under magnetic stirring at a speed of 300 r / min, the niobium oxalate solution prepared in step SS1 is added dropwise at a rate of 80 drops / min to the above-mentioned diammonium hydrogen phosphate solution beaker after pH adjustment. After stirring for 10 min, solution A is obtained. Then, nickel nitrate solution is added dropwise at a rate of 80 drops / min to solution A. After stirring for 30 min, solution B is obtained.

[0040] Step SS4: Add the solution B prepared in step SS3 to the CTAB solution to obtain emulsion C; and control the addition flow rate to be 100 drops / min;

[0041] Step SS5: Place the emulsion C in a thermostat at 30°C and stir at a constant temperature for 4 hours at a stirring speed of 700 r / min to obtain the treated emulsion C.

[0042] Step SS6: Transfer the emulsion C after step SS5 to a crystallization vessel and crystallize at 150℃ for 24h. Then, filter under vacuum of -0.05MPa. Wash 500mL of the filtered solid with distilled water five times. Then, dry the solid in a 90℃ constant temperature drying oven for 5h to obtain the Ni-Nb-P composite oxide precursor.

[0043] Step SS7: The Ni-Nb-P composite oxide precursor was calcined in a muffle furnace at 500℃ for 5h, and then reduced with hydrogen in a tube furnace at 500℃ for 5h. The hydrogen flow rate during the hydrogen reduction process was 50mL / min, to obtain the bulk Ni-Nb-P catalyst.

[0044] The XRD pattern of the unsupported bifunctional Ni-Nb-P catalyst prepared in this embodiment is shown below. Figure 1 The X-ray diffractometer used was a D8 Advance model manufactured by Bruker GmbH, Germany. Measurement conditions: diffraction source was Cu-Kα, wavelength... The tube voltage was 40kV, the tube current was 30mA, the scanning speed was 10° / min, the diffraction angle 2θ scanning range was 5°~90°, and the scanning step size was 0.01° / step. Figure 1It can be seen that the diffraction peaks at 36.38°, 41.13°, 41.76°, 42.81°, and 43.64° of the Ni-Nb-P sample are characteristic diffraction peaks of Ni3P (PDF74-1384). In the prepared catalyst, Ni mainly exists in the form of Ni3P, while NbOPO4 is amorphous.

[0045] The N2 adsorption-desorption isotherm of the unsupported bifunctional Ni-Nb-P catalyst prepared in this embodiment is as follows: Figure 2 As shown in (a), the pore size distribution is as follows Figure 2 (b) shows the results. The test was conducted using an ASAP2020 fully automated physicochemical adsorption analyzer manufactured by Micromeritics, Inc., USA. Test conditions: Approximately 0.2 g of sample was degassed at 250 °C for 12 h, during which time the vacuum level reached 10. -3 The sample was then subjected to low-temperature N2 adsorption and desorption in a liquid nitrogen cold trap at -196℃. The specific surface area of ​​the sample was calculated using the BET method, and the pore volume and pore size were evaluated using the BJH method. As shown in the figure, the isotherms all conform to Type IV of the IUPAC classification, indicating a typical mesoporous material with a large specific surface area and a relatively concentrated pore size distribution; the specific surface area is 180.12 m². 2 ·g -1 With an average pore size of 3.89 nm, the high specific surface area and suitable pore size provide more active centers for the catalyst.

[0046] The SEM image of the unsupported bifunctional Ni-Nb-P catalyst prepared in this embodiment is shown below. Figure 3 As shown. The measurements were performed using a Regulus 8100 scanning electron microscope manufactured by Hitachi, Japan, with an operating voltage of 5kV. Figure 3 It is evident that the prepared catalyst sample has a plate-like structure, which ensures the maximization of the catalyst's specific surface area and exposes more active sites.

[0047] The unsupported bifunctional Ni-Nb-P catalyst pyridine infrared spectrum (Py-FTIR) prepared in this embodiment is as follows: Figure 4 As shown. The infrared spectra of pyridine adsorbed on the catalyst surface were determined using a Bruker TENSOR 27 infrared spectrometer. Before testing, the sample was evacuated to 10⁻⁴ mmHg at 400℃ and maintained for 1 h; then cooled to room temperature to allow pyridine adsorption to reach saturation; after evacuation treatment at 100℃, 200℃, 300℃, and 400℃ for 1 h respectively, the infrared spectra of the adsorbed pyridine were measured. The amounts of B and L acids were calculated from the integrated peak areas of the spectra. Figure 4 It can be seen that the catalyst is at 1446 cm⁻¹ -1 and 1490cm -1The absorption peaks nearby are attributed to pyridine species adsorbed at L-acid centers, while the latter is attributed to pyridine species adsorbed at both L-acid and Brønsted acid centers. No absorption peak at 1540 cm⁻¹ was detected attributable to pyridine adsorbed at Brønsted acid centers. -1 The presence of L acid at different temperatures (near the catalyst) indicates that the acid centers in the Ni-Nb-P catalyst are mainly L acid. The total L acid content distribution at different temperatures is 123.05 mmol / g (100℃), 45.78 mmol / g (200℃), 27.54 mmol / g (300℃), and 10.86 mmol / g (200℃).

[0048] Examples 2 to 9 illustrate the application of the Ni-Nb-P catalyst prepared in Example 1 in different bio-oils.

[0049] Example 2: Hydrogenation Deoxygenation Reaction of Benzaldehyde

[0050] The catalyst prepared in Example 1 was applied to the hydrodeoxygenation reaction of benzaldehyde, which was carried out in a high-pressure reactor. The feedstock consisted of 1.5 g benzaldehyde, 0.2 g catalyst, and 15 ml dodecane. The system reaction temperature was adjusted to 80 °C; the hydrogen pressure was 2 MPa; the stirring speed was 500 r / min; and after 3 h of reaction, the conversion rate of benzaldehyde was measured to be 100%, and the selectivity for toluene was 98.50%. Increasing the reaction temperature to 160 °C and reacting for 10 h, the selectivity for methylcyclohexane reached 97.8%.

[0051] The reaction solution was filtered, and the recovered unsupported bifunctional catalyst was washed three times with 15 ml of dodecane. Equal amounts of benzaldehyde and dodecane were added, and a cyclic catalytic experiment was conducted under the same reaction conditions. After three cycles, the benzaldehyde conversion rate was 99.5%, and the methylcyclohexane selectivity was 96.2%. This indicates that the prepared Ni-Nb-P catalyst exhibits good catalytic performance for the hydrogenation deoxygenation reaction of benzaldehyde. Under mild conditions (80℃), benzaldehyde can be converted to toluene, and at 160℃, it can be hydrogenated to methylcyclohexane. After five cycles of reuse, the conversion rate and selectivity did not decrease significantly, indicating good catalytic performance and stability.

[0052] Example 3

[0053] The catalyst prepared in Example 1 was applied to the hydrodeoxygenation reaction of phenol. The starting material was 1.5 g guaiacol, the catalyst was 0.2 g, and the dodecane was 15 ml. The system reaction temperature was adjusted to 150 °C; the hydrogen pressure was 3 MPa, the stirring speed was 700 r / min, and after 2 h of reaction, the conversion rate of phenol was greater than 99.9%, and the selectivity for cyclohexane was 99.2%.

[0054] The reaction solution was filtered, and the recovered unsupported bifunctional catalyst was washed three times with 15 ml of dodecane. Equal amounts of phenol and dodecane were added, and a cyclic catalytic experiment was conducted under the same reaction conditions. After five cycles, the phenol conversion was greater than 99.9%, and the selectivity for cyclohexane was 98.4%. This indicates that the prepared Ni-Nb-P catalyst also exhibits high selectivity and high catalytic activity for the hydrodeoxygenation of guaiacol, and its catalytic activity did not significantly decrease after five cycles of reuse.

[0055] Example 4

[0056] The catalyst prepared in Example 1 was applied to the hydrodeoxygenation reaction of anisole. The raw materials were 1.5 g anisole, 0.2 g catalyst, and 15 ml dodecane. The reaction temperature was set at 180 °C; the hydrogen pressure was 2 MPa; the stirring speed was 600 r / min; and after 2 h of reaction, the anisole conversion was found to be greater than 99.9%, and the cyclohexane selectivity was 98.9%.

[0057] The reaction solution was filtered, and the recovered unsupported bifunctional catalyst was washed three times with 15 ml of dodecane. Equal amounts of anisole and dodecane were added, and a cyclic catalytic experiment was conducted under the same reaction conditions. After five cycles, the anisole conversion was 98.8%, and the cyclohexane selectivity was 97.9%. This indicates that the prepared Ni-Nb-P catalyst exhibits high selectivity and high catalytic activity for the hydrodeoxygenation of anisole. Furthermore, the selectivity and catalytic activity did not decrease after five cycles, demonstrating the catalyst's good catalytic performance and stability.

[0058] Example 5

[0059] The catalyst prepared in Example 1 was applied to the hydrodeoxygenation reaction of p-cresol. The feedstock consisted of 1.5 g of p-cresol, 0.2 g of catalyst, and 15 ml of dodecane. The reaction temperature was set at 160 °C; the hydrogen pressure was 2 MPa; the stirring speed was 500 r / min; and after 3 h of reaction, the conversion rate of p-cresol was found to be greater than 99.9%, and the selectivity for methylcyclohexane was 100%.

[0060] Example 6

[0061] Referring to Example 5, the difference from Example 5 is that the raw material was replaced with vanillin, the reaction temperature was 180°C, the reaction time was 2 hours, and the vanillin conversion rate was found to be greater than 99.9%, with a cyclohexane selectivity of 100%.

[0062] Example 7

[0063] Referring to Example 5, the difference from Example 5 is that the raw material was replaced with guaiacol, the reaction temperature was 180°C, the reaction time was 3 hours, and the conversion rate of guaiacol was greater than 99.9%, the selectivity of methylcyclohexane was 89%, and the selectivity of toluene was 11%.

[0064] Example 8

[0065] Referring to Example 5, the difference from Example 5 is that the raw material was replaced with diphenyl ether, the reaction temperature was 160°C, the reaction time was 1 hour, and the conversion rate of diphenyl ether was greater than 99.9%, and the selectivity of cyclohexane was 100%.

[0066] Example 9

[0067] Referring to Example 5, the difference from Example 5 is that the raw material was replaced with 4-benzyloxyphenol, the reaction temperature was 180°C, the reaction time was 3 hours, and the conversion rate of 4-benzyloxyphenol was greater than 99.9%, the selectivity of cyclohexane was 48%, and the selectivity of methylcyclohexane was 52%.

[0068] As can be seen from Examples 5 to 9, the Ni-Nb-P catalyst exhibits excellent catalytic effect on lignin derivatives. At relatively low temperatures (≤180℃), it can convert several common lignin derivatives with a conversion rate of >99%, and all of them are converted into deoxygenated products.

[0069] This invention employs a template method combined with a one-pot method to prepare an unsupported Ni-Nb-P mesoporous catalyst. Nb exists as an amorphous NbOPO4 species, while Ni mainly exists as Ni3P, resulting in a uniform, plate-like nanostructure. The Ni-Nb-P catalyst is dominated by medium-strong and strong acid sites, with L-acids as the primary acid centers. This provides more active sites for the lignin-derived hydrodeoxygenation reaction, exhibiting excellent performance in the conversion of lignin-derived oxygen-containing compounds. It fully utilizes the synergistic effect of the Ni3P active component and the NbOPO4 acidic sites to convert lignin-derived oxygen-containing compounds into hydrocarbons under relatively mild conditions of 80–180℃ and 1–3 MPa. The catalyst exhibits good stability, with almost no decrease in catalytic performance after five cycles, extending its lifespan and providing a reference for the efficient catalytic conversion of biomass into hydrocarbon fuels.

[0070] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A Ni-Nb-P unsupported catalyst, characterized in that: The catalyst includes Ni3P and NbOPO4. The catalyst has a mesoporous structure as determined by nitrogen adsorption-desorption test and a plate-like structure as determined by SEM test. The catalyst is prepared by mixing, stirring, crystallizing, drying, calcining, and reducing a soluble nickel salt, a soluble niobium salt, a template agent, and diammonium hydrogen phosphate. Specifically, the preparation includes the following steps: Step SS1: Weigh out a certain amount of niobium oxalate hydrate, nickel nitrate, hexadecyltrimethylammonium bromide, and diammonium hydrogen phosphate and dissolve them separately in beakers containing 10ml~20ml of deionized water for later use; Step SS2: Adjust the pH of the diammonium hydrogen phosphate solution to 2-6 using 85% phosphoric acid; Step SS3: Under magnetic stirring at a speed of 200~300 r / min, the niobium oxalate solution prepared in step SS1 is added dropwise to the beaker of the diammonium hydrogen phosphate solution that has been adjusted to pH. After stirring for 10 min, solution A is obtained. Then, nickel nitrate solution is added dropwise to solution A and stirred for 30 min to obtain solution B. Step SS4: Add the solution B prepared in step SS3 to the CTAB solution to obtain emulsion C; Step SS5: Place the emulsion C in a thermostat and stir at a constant temperature for 3-5 hours to obtain the treated emulsion C; Step SS6: Transfer the emulsion C after step SS5 to a crystallization vessel, crystallize at 150~160℃ for 18~24h, filter and wash the filtered solid, and then place the solid in a constant temperature drying oven at 80~120℃ for 4~10h to obtain the Ni-Nb-P composite oxide precursor. Step SS7: Calcine the Ni-Nb-P composite oxide precursor in a muffle furnace at 450-550℃ for 3-5 hours, and then reduce it with hydrogen in a tube furnace at 400-500℃ for 3-5 hours to obtain a bulk Ni-Nb-P catalyst.

2. The Ni-Nb-P unsupported catalyst according to claim 1, characterized in that, In step SS1, the molar ratio of niobium oxalate hydrate to nickel nitrate is between 0.5 and 3.

0. The amount of CTAB added is equal to 0.5 to 2 times the total molar amount of niobium oxalate hydrate and nickel nitrate, and the amount of diammonium hydrogen phosphate added is 1.0 to 2.5 times the total molar amount of niobium oxalate hydrate and nickel nitrate.

3. The Ni-Nb-P unsupported catalyst according to claim 1, characterized in that, In step SS3, the dropping rate of niobium oxalate solution and nickel nitrate solution is 60~120 drops / min.

4. The Ni-Nb-P unsupported catalyst according to claim 1, characterized in that, In step SS4, the addition rate of solution B to the CTAB solution is 60-120 drops / min.

5. The Ni-Nb-P unsupported catalyst according to claim 1, characterized in that, In step SS5, the thermostat temperature is 30~40℃ and the stirring speed is 700r / min.

6. The Ni-Nb-P unsupported catalyst according to claim 1, characterized in that, In step SS6, the filtration and solid washing are carried out under a vacuum of -0.05 to -0.07 MPa. The filtered solid is then washed with distilled water, using 400-500 mL of distilled water each time, for 3-5 washes.

7. The Ni-Nb-P unsupported catalyst according to claim 1, characterized in that, The hydrogen flow rate in step SS7 during the hydrogen reduction process is 30-50 mL / min.

8. The application of the Ni-Nb-P unsupported catalyst according to any one of claims 1-7 in the hydrodeoxygenation of oxygen-containing compounds in bio-oils, characterized in that: Ni-Nb-P catalyst and bio-oil were placed in a batch reactor with a bio-oil to catalyst mass ratio of 5:1 to 20:

1. The hydrodeoxygenation reaction was carried out for 10 min to 6 h under the conditions of hydrogen pressure of 1 MPa to 4 MPa, temperature of 80 to 200 °C, and stirring speed of 500 to 800 r / min to obtain the hydrodeoxygenation product.

9. The application of the Ni-Nb-P unsupported catalyst according to claim 8 in the hydrodeoxygenation of oxygen-containing compounds in bio-oils, characterized in that: 10-20 ml of dodecane was also added to the batch reactor.

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