Metal oxide modified hollow molecular sieve catalyst, method for its preparation and use in the synthesis of high-density endothermic aviation fuels

Abstract

The application discloses a preparation method of a metal oxide modified hollow molecular sieve catalyst, which comprises the following steps: (1) treating a synthesized hollow ZSM-5 molecular sieve with an alkali; (2) preparing a reducible metal oxide precursor solution; (3) adding the hollow ZSM-5 molecular sieve into the reducible metal oxide precursor solution; (4) removing excessive water by rotary evaporation; (5) drying and calcining; (6) measuring a saturated water absorption amount; (7) preparing an active metal precursor solution; (8) loading the active metal on the hollow molecular sieve; and (9) ultrasonic treatment, drying and calcining. The application further discloses the metal oxide modified hollow molecular sieve catalyst and the use of the catalyst in a catalytic reaction for preparing high-density endothermic aviation fuel from polycyclic aromatic hydrocarbons through hydrogenation conversion.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and in particular relates to a metal oxide modified hollow molecular sieve catalyst, a preparation method thereof and application in the synthesis of high-density endothermic aviation fuel. Background Art

[0002] High-density aviation fuel, a mixture of single- or multi-component C8-C16 hydrocarbons, is a power source for supersonic aircraft and weapon systems. It is primarily used in aircraft, rockets, missiles, satellites, and more. Compared to conventional petroleum-based aviation fuel, high-density aviation fuel boasts higher density, volumetric calorific value, and thermal oxidation stability. Within a limited tank volume, it can significantly increase missile range, aircraft flight distance, and payload. The development of high-density aviation fuel is crucial for strengthening my country's national defense and promoting the development of military unmanned aerial vehicles.

[0003] One-step deep hydrogenation of polycyclic aromatic hydrocarbons (PAHs), such as acenaphthene, acenaphthylene, fluorene, phenanthrene, anthracene, and their alkylated derivatives, can produce high-density aviation fuel with a density ≥0.90 g / mL. This fuel contains ≥95% by weight of condensed cycloalkanes and exhibits high volumetric calorific value, high thermal and oxidative stability, and excellent low-temperature performance. PAHs are extremely reactive due to their high resonance energy and steric hindrance. Hydrogenation of the first PAH ring typically consumes 1 or 2 moles of hydrogen, but hydrogenation of the last ring requires 3 moles of hydrogen. Therefore, higher reaction temperatures and pressures are required to achieve complete saturation of PAHs.

[0004] Metal sulfide catalysts were first used in aromatic hydrogenation reactions, but metal sulfides have poor hydrogenation saturation ability and require high temperature (>350°C) and high pressure (>6MPa) to achieve complete hydrogenation. However, due to the limitations of thermodynamic equilibrium, the conversion rate of aromatic hydrogenation is low at high temperature, and high temperature will cause severe cracking of aromatic hydrogenation products, reducing the yield. Molecular sieve-loaded precious metal catalysts exhibit excellent low-temperature hydrogenation activity and can catalyze the hydrogenation saturation of aromatics at a more suitable temperature, but the microporous structure of the molecular sieve limits the mass transfer of large molecular aromatic compounds. Therefore, the development of efficient hydrogenation catalysts to achieve hydrogenation saturation of polycyclic aromatic hydrocarbons under mild conditions is a challenge faced by the hydrogenation of polycyclic aromatic hydrocarbons to produce high-density aviation fuel.

[0005] In patent CN113368891A, the applicant disclosed a method for preparing a hollow ZSM-5 molecular sieve catalyst and its use in catalyzing the hydrogenation of condensed-ring aromatic hydrocarbons to produce high-density aviation fuel. It was found that the hollow molecular sieve catalyst exhibited excellent deep hydrogenation activity for polycyclic aromatic hydrocarbons under mild reaction conditions. However, its deep hydrogenation ability for polycyclic aromatic hydrocarbons was poor under high weight hourly space velocity conditions, and the product contained a large number of intermediate hydrogenation products, which was not conducive to the synthesis of high-density aviation fuel.

[0006] The present invention is proposed for this purpose. Summary of the Invention

[0007] In order to further enhance the deep hydrogenation saturation activity of hollow molecular sieve catalysts, the present invention adopts a rotary evaporation-assisted impregnation method to prepare a reducible metal oxide-modified hollow molecular sieve catalyst to enhance the hydrogen overflow ability of the catalyst and strengthen the interaction between the metal and the support in the catalyst, thereby promoting the deep hydrogenation saturation of polycyclic aromatic hydrocarbons to synthesize high-density endothermic aviation fuel.

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

[0009] The first aspect of the present invention discloses a method for preparing a metal oxide modified hollow molecular sieve catalyst, comprising the following steps:

[0010] (1) Synthesizing a hollow ZSM-5 molecular sieve carrier by an alkali treatment method; the specific operation steps are shown in patent CN113368891A;

[0011] (2) preparing a reducible metal oxide precursor solution;

[0012] (3) adding the hollow ZSM-5 molecular sieve powder of step (1) to the reducible metal oxide precursor solution of (2), stirring at room temperature for 2-16 hours to mix uniformly;

[0013] (4) removing excess water from the mixture obtained in (3) by rotary evaporation;

[0014] (5) drying the solid product obtained in (4), calcining it at a certain temperature for a period of time, and collecting the solid powder, which is the metal oxide modified hollow molecular sieve;

[0015] (6) Measure the saturated water absorption of the metal oxide modified hollow molecular sieve, repeat the measurement three times, and take the average value;

[0016] (7) preparing an active metal precursor solution using water as a solvent, wherein the mass of water in the active metal precursor solution is equal to the saturated water absorption capacity of the metal oxide-modified hollow molecular sieve used; adjusting the pH value of the active metal precursor solution to 9-13 using ammonia water and stirring at room temperature for 0.5-3 hours; preferably, the solution pH value is 11.5 and the stirring time is 2 hours;

[0017] (8) The active metal is loaded onto the metal oxide modified hollow molecular sieve by an enhanced strong electrostatic adsorption method; wherein the loading amount of the active metal is 0.02-6.00 wt%; the metal oxide modified hollow molecular sieve is added to the metal precursor solution with the adjusted pH value in (7), and vigorously stirred at the same time, and an electrostatic adsorption process is performed to load the active metal onto the molecular sieve carrier; more preferably, the loading amount of the active metal is 0.8-2.0 wt%.

[0018] (9) The catalyst sample obtained after electrostatic adsorption in (8) is subjected to ultrasonic treatment for a period of time; then vacuum dried at a certain temperature for a period of time; and the dried product is calcined for a period of time to obtain a metal oxide modified hollow molecular sieve catalyst.

[0019] Preferably, the reducible metal oxide precursor in step (2) is one or more of cerium sulfate, cerium nitrate, cerium isopropoxide, titanium isopropoxide, titanium tetrachloride, tetrabutyl titanate, tetraethyl titanate, zirconium n-butoxide, zirconium n-propoxide, zirconium sulfate, tungsten chloride or ammonium tungstate; cerium nitrate is more preferred.

[0020] Preferably, the solid-liquid mass ratio of the hollow ZSM-5 molecular sieve powder to the reducible metal oxide precursor solution in step (3) is 1:5 to 1:20; the final loading amount of the reducible metal oxide is 0.5 to 9 wt%; more preferably, the solid-liquid ratio is 1:10 and the loading amount is 3 wt%.

[0021] Preferably, in step (4), vacuum is drawn by a vacuum pump and excess water is removed by rotary evaporation; wherein the rotation speed is 80-120 rpm and the rotary evaporation temperature is 40-60°C.

[0022] Preferably, the drying temperature in step (5) is 80-130°C and the time is 5-16h, more preferably the drying temperature is 120°C and the time is 6h; the roasting temperature is 400-600°C and the time is 3-10h, more preferably the roasting temperature is 500°C and the time is 6h.

[0023] Preferably, the active metal in step (7) is one or more of Pt, Pd, Ir, Ru, Rh, Au, Ni, Cu, Zn, Co or Fe; more preferably, the active metal precursor is tetraammine platinum nitrate.

[0024] Preferably, the ultrasonic treatment time in step (10) is 0.2-2h, preferably 0.5h; the vacuum drying temperature is 60-120°C and the time is 6-24h, preferably the vacuum drying temperature is 80°C and the time is 12h; the calcination temperature is 300-500°C and the calcination time is 3-10h, preferably the calcination temperature is 450°C and the calcination time is 4h.

[0025] The second aspect of the present invention discloses a metal oxide modified hollow molecular sieve catalyst prepared by the preparation method.

[0026] The third aspect of the present invention discloses the use of the metal oxide modified hollow molecular sieve catalyst in the catalytic reaction of hydrogenating and converting polycyclic aromatic hydrocarbons to prepare high-density endothermic aviation fuel.

[0027] Preferably, the method for catalytic reaction of using a metal oxide modified hollow molecular sieve catalyst for the hydrogenation conversion of polycyclic aromatic hydrocarbons to prepare high-density endothermic aviation fuel comprises the following steps:

[0028] (A) crushing the metal oxide modified hollow molecular sieve catalyst into 30-40 mesh particles using a fixed bed reactor; and pressing the particles into 30-40 mesh particles using a powder tablet press at a pressure of 10 MPa;

[0029] (B) loading the obtained catalyst particles into a stainless steel reaction tube of a fixed bed reactor, fixing the catalyst particles in the middle of the stainless steel reaction tube with quartz wool, filling the remaining portion of the reaction tube with silicon carbide, and then installing the fixed bed reactor;

[0030] (C) reducing the metal oxide-modified hollow molecular sieve catalyst with hydrogen, adjusting the reactor pressure to be stable at 2-8 MPa and the hydrogen flow rate to be 100-300 mL / min; raising the temperature to 300-500° C. and reducing for 2-6 hours; preferably, the pressure is 4 MPa, the hydrogen flow rate is 100-200 mL / min, and the reduction temperature is 450° C.;

[0031] Before using a fixed-bed reactor, the pressure of the fixed-bed reactor is adjusted to 5 MPa with nitrogen for leak detection. If there is no significant change in the pressure of the fixed-bed reactor within 0.5 h, it indicates that the sealing of the device is good.

[0032] (D) dissolving a condensed ring aromatic hydrocarbon in a condensed ring alkane solvent; wherein the condensed ring aromatic hydrocarbon is one or more of naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene and alkyl substituents thereof, and the condensed ring alkane is one or more of decahydronaphthalene, perhydrofluorene, and perhydroacenaphthene, preferably decahydronaphthalene;

[0033] (E) Adjust the reaction pressure to 2-8 MPa, the reaction temperature to 100-300°C, the hydrogen-to-oil ratio to 200-800 NmL / mL, and the feed mass space velocity (WHSV) of the raw material condensed aromatic hydrocarbon solution to 10-50 h -1 ;

[0034] (F) collecting the product after the hydrogenation reaction in (E) to obtain high-density endothermic aviation fuel; it does not need to be separated and can be directly used as aviation fuel.

[0035] Beneficial effects of the present invention:

[0036] The present invention prepares a metal oxide-modified hollow molecular sieve catalyst by a rotary evaporation-assisted impregnation method, wherein the CeO2-modified hollow Pt / hZ catalyst exhibits strong hydrogen overflow ability and excellent metal-support synergistic catalytic ability, significantly improving the deep hydrogenation saturation activity of the hollow Pt / hZ catalyst for polycyclic aromatic hydrocarbons, and can achieve deep hydrogenation saturation of polycyclic aromatic hydrocarbons under more stringent reaction conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 X-ray diffraction patterns (XRD) of Pt / hZ, Pt / 1CehZ, Pt / 3CehZ and Pt / 6CehZ catalysts.

[0038] Figure 2 This is a high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) image of the Pt / 3CehZ catalyst.

[0039] Figure 3 Hydrogen temperature-programmed desorption data (H2-TPD) diagrams of Pt / hZ (a), Pt / 1CehZ (b), Pt / 3CehZ (c) and Pt / 6CehZ (d)Z catalysts. DETAILED DESCRIPTION

[0040] In order to make the purpose of the present invention, technical scheme clearer, be described in detail with reference to the following examples, embodiment is intended to illustrate the content of the present invention, rather than further limit the scope of protection of the present invention. The process, conditions, reagents, experimental techniques etc. implemented, except the content specifically mentioned below, are common knowledge and common common sense in this area, and the present invention has no particular restrictions. The experimental techniques for the unremarked specific conditions in each embodiment are usually according to conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise indicated, the implication of all professional terms and scientific terms used in this specification sheets is the same as the implication generally understood by those skilled in the art to which the present invention belongs. However, in case of conflict, the present specification sheets comprising the definitions shall prevail.

[0041] Example: Synthesis of CeO2-modified hollow ZSM-5 molecular sieve catalyst and its application in the catalytic reaction of hydroconversion of polycyclic aromatic hydrocarbons to produce high-density endothermic aviation fuel, the steps are as follows:

[0042] (1) Weigh a certain amount of cerium nitrate and dissolve it in 20 mL of water. By changing the amount of cerium nitrate added, the CeO2 doping amount in the final molecular sieve sample is controlled to be 1 wt%, 3 wt% and 6 wt%, respectively. After the cerium nitrate is evenly dissolved, add 2 g of hollow ZSM-5 molecular sieve and continue stirring at room temperature for 8 h. After stirring, fix the molecular sieve sample on a rotary evaporator to remove excess water, set the rotation speed to 90 rpm, and the evaporation temperature to 50 ° C. Then, place the evaporated molecular sieve in an oven and dry it at 120 ° C for 6 h. Finally, transfer it to a muffle furnace and calcine it at 500 ° C for 6 h. Collect the products. According to the different doping amounts, the synthesized metal oxide modified hollow molecular sieve samples are named 1CehZ, 3CehZ and 6CehZ.

[0043] (2) Weigh 0.04g of tetraammine platinum nitrate and dissolve it in water to prepare a metal precursor solution. Add ammonia water dropwise to adjust the pH of the solution to 11.5, stir for 2.0h, and after the pH stabilizes, add 2.0g of the CeO2-modified hollow ZSM-5 molecular sieve obtained in step (1), stir vigorously for 0.5h, and then ultrasonicate for 0.5h. Then, vacuum dry in a drying oven at 80℃ for 12h, place in a muffle furnace and heat to 450℃ at a rate of 1℃ / min and calcine for 4h to obtain CeO2-modified hollow ZSM-5 molecular sieve catalyst (metal oxide modified hollow molecular sieve catalyst), which are respectively recorded as Pt / 1CehZ, Pt / 3CehZ and Pt / 6CehZ. Finally, use a powder tablet press to press the synthesized catalyst into 30-40 mesh particles.

[0044] (3) Weigh 1 g of compressed 30-40 mesh catalyst and place it into the stainless steel reaction tube of the fixed-bed reactor. Fill both ends with quartz wool and then silicon carbide, and then install it into the fixed-bed reactor. After checking the seal with nitrogen, pressurize the device to 4 MPa with hydrogen at a flow rate of 200 mL / min. The temperature is raised and the catalyst is activated by in-situ reduction at 450°C for 4 h.

[0045] (4) After the catalyst reduction is completed, the temperature of the heating furnace is lowered to the catalytic reaction temperature, and the hydrogen flow rate is set to 100 mL / min; the high-pressure liquid phase feed pump is turned on, and the reaction raw material polycyclic aromatic hydrocarbon phenanthrene is fed into the reaction tube for catalytic reaction. The solvent is decahydronaphthalene, and the weight hourly space velocity is 21.6 h -1 After the reaction stabilized, the liquid product was separated into gas and liquid and collected through a sampling port, and then analyzed using Shimadzu gas chromatography.

[0046] Comparative Example: An unmodified hollow ZSM-5 molecular sieve supported Pt catalyst was synthesized for the catalytic reaction of polycyclic aromatic hydrocarbons hydrogenation to produce high-density endothermic aviation fuel. For comparison, the steps are as follows:

[0047] (1) 0.04 g of tetraammine platinum nitrate was weighed and dissolved in water to prepare a metal precursor solution. Ammonia was added dropwise to adjust the pH of the solution to 11.5. The solution was stirred for 2 h. After the pH stabilized, 2.0 g of the synthesized hollow ZSM-5 molecular sieve was added. The solution was vigorously stirred for 0.5 h and then ultrasonicated for 0.5 h. The solution was vacuum dried at 80 °C in a drying oven for 12 h. The solution was placed in a muffle furnace and heated to 450 °C at a rate of 1 °C / min and calcined for 4 h to obtain the synthesized hollow ZSM-5 molecular sieve catalyst, which was recorded as Pt / hZ. Finally, the synthesized catalyst was pressed into 30-40 mesh particles using a powder tablet press.

[0048] (2) 1 g of compressed 30-40 mesh Pt / hZ catalyst was weighed and loaded into the stainless steel reaction tube of the fixed-bed reactor. Both ends were filled with quartz wool and then silicon carbide, and then installed in the fixed-bed reactor. After a leak check with nitrogen, the device was pressurized to 4 MPa with hydrogen at a flow rate of 200 mL / min. The temperature was then increased and the catalyst was activated by in-situ reduction at 450°C for 4 h.

[0049] (3) After the catalyst reduction is completed, the temperature of the heating furnace is lowered to the catalytic reaction temperature, and the hydrogen flow rate is set to 100 mL / min. The high-pressure liquid phase feed pump is turned on, and the reaction raw material polycyclic aromatic hydrocarbon phenanthrene is fed into the reaction tube for catalytic reaction. The solvent is decahydronaphthalene, and the weight hourly space velocity is 21.6 h -1 After the reaction stabilized, the liquid product was separated into gas and liquid and collected through a sampling port, and then analyzed using Shimadzu gas chromatography.

[0050] Figure 1 The X-ray diffraction patterns (XRD) of Pt / hZ, Pt / 1CehZ, Pt / 3CehZ and Pt / 6CehZ catalysts are shown in Figure 2. Figure 1 As can be seen, all Pt catalysts exhibit characteristic diffraction peaks of MFI zeolite at 7.97°, 8.82°, 23.32°, 23.95°, and 24.41° (PDF#44-0003). With increasing CeO2 doping, the characteristic peaks of CeO2 fluorite structure at 28.6°, 33.1°, 47.5°, and 56.4° gradually intensify (PDF#34-0394), demonstrating successful CeO2 doping into the hollow ZSM-5 zeolite. Furthermore, no characteristic peaks associated with metallic Pt were detected, indicating good Pt dispersion in all synthesized catalysts.

[0051] Figure 2 This is a high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) image of the Pt / 3CehZ catalyst. Figure 2It can be observed that the synthesized molecular sieve has a regular hollow structure and the metal particles are highly dispersed on its surface, showing excellent active metal dispersion, which is conducive to exposing more metal active sites to promote hydrogenation.

[0052] Figure 3 The hydrogen temperature programmed desorption data (H2-TPD) of Pt / hZ (a), Pt / 1CehZ (b), Pt / 3CehZ (c) and Pt / 6CehZ (d) Z catalysts are shown in Figure 2. Figure 3 It can be seen that with the increase of CeO2 doping amount, the desorption amount of hydrogen gradually increases, indicating that the hydrogen overflow ability of the catalyst is further enhanced, which is conducive to promoting the hydrogen overflow hydrogenation path of polycyclic aromatic hydrocarbons and enhancing the deep hydrogenation activity of the catalyst.

[0053] Table 1 shows the quantitative H2-TPD desorption data for Pt / hZ, Pt / 1CehZ, Pt / 3CehZ, and Pt / 6CehZ catalysts. It can be clearly observed from Table 1 that the order of hydrogen spillover ability of different Pt catalysts is Pt / 6CehZ > Pt / 3CehZ > Pt / 1CehZ > Pt / hZ, indicating that the introduction of CeO2 significantly enhances the hydrogen spillover performance of the hollow molecular sieve catalyst.

[0054] Table 1 Quantitative H2-TPD desorption data of Pt / hZ, Pt / 1CehZ, Pt / 3CehZ and Pt / 6CehZ catalysts

[0055]

[0056] A fixed bed reactor was used with a comparative catalyst: hollow Pt / hZ catalyst. The catalytic reaction pressure was 4 MPa, the temperature was 180-260°C, the hydrogen-to-oil ratio was 500 NmL / mL, and the weight hourly space velocity was 21.6 h -1 High-density aviation fuel was synthesized under hydrogenation conditions using the condensed aromatic hydrocarbon phenanthrene as the feedstock and decahydronaphthalene as the solvent. Table 2 shows the phenanthrene conversion and hydrogenation product distribution under different reaction conditions. It can be seen that the Pt / hZ catalyst, unmodified with metal oxides, exhibits poor selectivity for the deep hydrogenation products octahydrophenanthrene and perhydrophenanthrene at high weight hourly space velocities. Even at a high temperature of 260°C, the selectivity for the fully hydrogenated product perhydrophenanthrene is only 42.38%, indicating poor deep hydrogenation activity.

[0057] Table 2 Pt / hZ catalyst catalyzes phenanthrene hydrogenation saturation

[0058] serial number Temperature (℃) Conversion rate (%) Dihydrophenanthrene (%) Tetrahydrophenanthrene (%) Octahydrophenanthrene (%) Perhydrophenanthrene (%) 1 180 47.02 49.65 35.51 13.86 0.98 2 200 69.02 40.05 21.61 36.67 1.67 3 220 86.83 22.36 9.78 62.23 5.63 4 240 96.43 5.94 1.90 74.53 17.63 5 260 99.90 0.22 0.44 56.96 42.38

[0059] A fixed bed reactor was used with CeO2-modified hollow Pt / 1CehZ and Pt / 3CehZ catalysts. The reaction pressure was 4 MPa, the temperature was 180-260°C, the hydrogen-to-oil ratio was 500 NmL / mL, and the weight hourly space velocity was 21.6 h -1 Under the conditions of 1000 nm, high-density aviation fuel was synthesized using condensed aromatic hydrocarbon phenanthrene as raw material and decahydronaphthalene as solvent under hydrogenation conditions. Tables 3 and 4 show the conversion rate and hydrogenation product distribution data of phenanthrene hydrogenation catalyzed by Pt / 1CehZ and Pt / 3CehZ under different reaction conditions, respectively. It can be clearly observed that the catalytic activity of the hollow molecular sieve catalyst is further enhanced after CeO2 modification. Compared with the Pt / hZ catalyst under the same temperature conditions, Pt / 1CehZ and Pt / 3CehZ show higher phenanthrene conversion rate and higher selectivity for deep hydrogenation products octahydrophenanthrene and perhydrophenanthrene. This is because the hydrogen overflow ability of the hollow molecular sieve catalyst is enhanced after CeO2 modification, and the synergistic catalytic ability of the metal-support is promoted, thus showing better performance in deep hydrogenation saturation of polycyclic aromatic hydrocarbons.

[0060] Table 3 Pt / 1CehZ catalyst catalyzes phenanthrene hydrogenation saturation

[0061] serial number Temperature (℃) Conversion rate (%) Dihydrophenanthrene (%) Tetrahydrophenanthrene (%) Octahydrophenanthrene (%) Perhydrophenanthrene (%) 1 180 62.25 40.70 38.01 18.26 3.03 2 200 80.03 31.84 22.25 39.69 6.22 3 220 93.22 16.45 8.69 63.78 11.08 4 240 98.01 3.01 3.02 61.92 32.05 5 260 99.89 0.29 0.21 38.66 60.84

[0062] Table 4 Pt / 3CehZ catalyst catalyzes phenanthrene hydrogenation saturation

[0063] serial number Temperature (℃) Conversion rate (%) Dihydrophenanthrene (%) Tetrahydrophenanthrene (%) Octahydrophenanthrene (%) Perhydrophenanthrene (%) 1 180 89.12 26.75 13.02 44.21 16.02 2 200 96.21 12.02 6.02 33.74 48.22 3 220 98.01 3.01 3.25 17.50 76.24 4 240 99.22 1.06 1.25 7.64 90.05 5 260 99.96 0.13 0.09 3.17 96.61

[0064] The embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A metal oxide modified hollow molecular sieve catalyst for the catalytic reaction of polycyclic aromatic hydrocarbons hydroconversion to produce high-density endothermic aviation fuel, characterized in that: The preparation method of the metal oxide modified hollow molecular sieve catalyst comprises the following steps: (1) Synthesis of hollow ZSM-5 molecular sieve carrier by alkali treatment; (2) preparing a reducible metal oxide precursor solution; the reducible metal oxide precursor is one or more of cerium sulfate, cerium nitrate, cerium isopropoxide, titanium isopropoxide, titanium tetrachloride, tetrabutyl titanate, tetraethyl titanate, zirconium n-butoxide, zirconium n-propoxide, zirconium sulfate, tungsten chloride or ammonium tungstate; (3) adding the hollow ZSM-5 molecular sieve powder of step (1) to the reducible metal oxide precursor solution of step (2) and mixing them uniformly; the solid-liquid mass ratio of the hollow ZSM-5 molecular sieve powder to the reducible metal oxide precursor solution is 1:5 to 1:20; and the final loading amount of the reducible metal oxide is 0.5 to 9 wt%; (4) removing excess water from the mixture obtained in step (3) by rotary evaporation; evacuating the mixture by a vacuum pump and removing excess water by rotary evaporation; wherein the rotation speed is 80-120 rpm and the rotary evaporation temperature is 40-60°C; (5) drying the solid product obtained in step (4), calcining it at a certain temperature for a period of time, and collecting the solid powder, which is the metal oxide modified hollow molecular sieve; (6) Measure the saturated water absorption of the metal oxide modified hollow molecular sieve, repeat the measurement three times, and take the average value; (7) preparing an active metal precursor solution using water as a solvent, wherein the mass of water in the active metal precursor solution is equal to the saturated water absorption capacity of the metal oxide modified hollow molecular sieve used; The pH value of the active metal precursor solution is adjusted to 9-13 using ammonia water; the active metal is one or more of Pt, Pd, Ir, Ru, Rh, Au, Ni, Cu, Zn, Co or Fe; (8) The active metal is loaded onto the metal oxide modified hollow molecular sieve by electrostatic adsorption; wherein the loading amount of the active metal is 0.02-6.00 wt%; (9) The catalyst sample obtained after electrostatic adsorption in step (8) is subjected to ultrasonic treatment for a period of time; then vacuum dried at a certain temperature for a period of time; and the dried product is calcined for a period of time to obtain a metal oxide modified hollow molecular sieve catalyst.

2. The use according to claim 1, characterized in that In step (5), the drying temperature is 80-130°C and the time is 5-16 hours; the calcination temperature is 400-600°C and the time is 3-10 hours.

3. The use according to claim 1, characterized in that In step (9), the ultrasonic treatment time is 0.2-2 hours; the vacuum drying temperature is 60-120°C and the time is 6-24 hours; the calcination temperature is 300-500°C and the calcination time is 3-10 hours.

4. The use according to claim 1, characterized in that A method for catalytically reacting a metal oxide-modified hollow molecular sieve catalyst for the hydrogenation conversion of polycyclic aromatic hydrocarbons to produce high-density endothermic aviation fuel comprises the following steps: (A) using a fixed bed reactor to granulate the metal oxide modified hollow molecular sieve catalyst into particles of 30-40 mesh; (B) loading the obtained catalyst particles into a stainless steel reaction tube of a fixed bed reactor, fixing the catalyst particles in the middle of the stainless steel reaction tube with quartz wool, filling the remaining portion of the reaction tube with silicon carbide, and then installing the fixed bed reactor; (C) reducing the metal oxide modified hollow molecular sieve catalyst with hydrogen, adjusting the reactor pressure to be stable at 2-8 MPa and the hydrogen flow rate to be 100-300 mL / min; raising the temperature to 300-500° C. and reducing for 2-6 hours; (D) dissolving a condensed ring aromatic hydrocarbon in a condensed ring alkane solvent; wherein the condensed ring aromatic hydrocarbon is one or more of naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene and alkyl substituents thereof, and the condensed ring alkane is one or more of decahydronaphthalene, perhydrofluorene and perhydroacenaphthene; (E) Adjust the reaction pressure to 2-8 MPa, the reaction temperature to 100-300°C, the hydrogen-to-oil ratio to 200-800 NmL / mL, and the feed mass space velocity of the raw material condensed ring aromatic hydrocarbon solution to 10-50 h -1 ; (F) Collecting the product after the hydrogenation reaction in (E) to obtain high-density endothermic aviation fuel.

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