Nitrogen-doped titanium dioxide supported Pd(OH)2 catalysts, their preparation methods and applications

Abstract

The application discloses a nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst and a preparation method and application thereof. The preparation method of the catalyst comprises the following steps: (1) preparing a nitrogen-doped titanium dioxide carrier; (2) dissolving PdCl2 in hydrochloric acid to obtain a solution A; (3) adding the nitrogen-doped titanium dioxide carrier and deionized water into a container, stirring at 50-70 DEG C for 10-20 min to make them uniformly mixed; slowly adding the solution A into the container containing the mixture, and continuing to stir for 5-7 h; then adjusting the pH to > 10 by using an alkaline solution, continuing to stir for 1-3 h, and continuing to stir for 1-3 h after the heating is turned off; finally, performing suction filtration, drying, and obtaining the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst. The application discloses application of the catalyst in preparation of TAIW from HBIW through two-step hydrogenolysis debenzylization, and the catalyst exhibits good product yield and stability in the two-step reaction.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, its preparation method, and its application in the two-step hydrogen debenzylation of hexabenzylhexaazaisowurtzite (HBIW). Background Technology

[0002] In both military and civilian fields, improving the energy density of explosives and propellants is an important research direction. Energy density refers to the energy stored per unit volume or unit mass, and it is crucial for explosive performance and propulsion effectiveness. Early explosives and propellants used traditional nitrate and organic explosives, which had relatively low energy densities, limiting the performance of explosive and propulsion systems. Materials with broad application prospects in rocket, propellant, and explosive chemistry are typically high-energy-density materials (HEDMs).

[0003] In the field of energetic materials, the current main focus is on developing advanced solid propellants with higher energy (Is), environmentally friendly combustion products, and insensitivity to explosions. CL-20 is the highest-energy and highest-density compound known among organic chemicals, initially synthesized by Nielsen in 1986. The debenzylation of HBIW is considered a key step in the synthesis of CL-20. Because of the competitive nitration of the benzene ring, direct nitration of HBIW to CL-20 via nitration is unsuccessful; therefore, debenzylation of HBIW via catalytic hydrogenolysis is necessary before nitration. The debenzylation reaction of HBIW involves multiple steps, resulting in high costs due to the use of large amounts of catalyst. Furthermore, the catalyst is prone to deactivation during the reaction, leading to numerous side reactions and low catalyst recycling rates and yields.

[0004] This invention prepares a nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, which has high reactivity, high selectivity and stability for the product, and produces very few by-products during the reaction, greatly improving the rate and yield of HBIW hydrogen debenzylase. Summary of the Invention

[0005] To address the aforementioned problems, this invention discloses a nitrogen-doped titanium dioxide-supported Pd(OH)2 catalyst, its preparation method, and its application in the two-step hydrogen debenzylation of hexabenzylhexaazaisowurtzite (HBIW).

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a nitrogen-doped titanium dioxide-supported Pd(OH)2 catalyst, comprising the following specific steps:

[0008] (1) Preparation of nitrogen-doped titanium dioxide support: Titanium-containing organic matter and anhydrous ethanol are mixed, and then a certain amount of nitrogen-containing organic matter is added. The mixture is stirred continuously for 22-24 hours, centrifuged, and dried in a forced-air oven at 100-120℃ for 6-8 hours. After that, it is ground to obtain powder. Finally, the powder is placed in a muffle furnace and calcined at 300-500℃ for 1-4 hours. After cooling to room temperature, nitrogen-doped titanium dioxide support is obtained. This support is denoted as TiO2-mN-xy, where x represents the calcination temperature, y represents the calcination time, and m represents the molar percentage of nitrogen element in titanium element, m = 1%-5%, and m is calculated according to the feed ratio. The nitrogen-containing organic matter is at least one of pyrrole, pyridine, 1,3,5-tris(4-aminophenyl)benzene, melamine, and L-glutamine.

[0009] (2) Dissolve PdCl2 in hydrochloric acid to obtain solution A;

[0010] (3) Add the nitrogen-doped titanium dioxide support and deionized water obtained in step (1) to the container, and stir in a water bath at 60-70℃ for 10-20 min to make it evenly mixed; take the solution A obtained in step (2) and slowly add it dropwise to the container containing the mixture, and continue stirring for 5-7 h; then use an alkaline solution to adjust the pH to >10 (preferably 11-13, more preferably 11), continue stirring for 1-3 h, turn off the heating and continue stirring for 1-3 h; finally, filter, and the obtained sample is dried under vacuum to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, so that the loading of Pd = mass of Pd / (mass of Pd + mass of nitrogen-doped titanium dioxide support) × 100% = 5wt%-10wt%, where the mass of Pd refers to the mass of Pd element contained in the added solution A.

[0011] Further, in step (1), the titanium-containing organic compound is at least one of tetraethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate.

[0012] Further, in step (1), the volume ratio of the titanium-containing organic matter to anhydrous ethanol is 1:10-30.

[0013] Furthermore, in step (1), the nitrogen-containing organic compound is 1,3,5-tris(4-aminophenyl)benzene, m = 5%, the calcination temperature is 350℃, and the calcination time is 2h.

[0014] Further, in step (1), the dispersant is first dissolved in anhydrous ethanol, and then a titanium-containing organic compound is added. The dispersant is selected from one of triethoxysilane, silane ether, polyethylene glycol, sodium dodecylbenzenesulfonate, and hexadecyltrimethylammonium bromide. The mass-to-volume ratio of the dispersant to the titanium-containing organic compound is (1-3) g: 10 mL, preferably 2 g: 10 mL. Even further, the dispersant is selected from sodium dodecylbenzenesulfonate or hexadecyltrimethylammonium bromide, and the nitrogen-containing organic compound is 1,3,5-tris(4-aminophenyl)benzene, m = 5%, calcined at 400°C for 2 hours.

[0015] Further, in step (3), the alkaline solution is an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, or ammonia.

[0016] Furthermore, in step (3), the vacuum drying temperature is 80-110℃ and the vacuum drying time is 6-12h.

[0017] In a second aspect, the present invention provides a nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst prepared according to the preparation method described in the first aspect.

[0018] Thirdly, the present invention provides the application of the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst in the two-step hydrogenodebenzylhexaazaisowurtzite (HBIW) to tetraacetylhexaazaisowurtzite (TAIW).

[0019] The preparation of TAIW from hexabenzylhexaazaisowrutzane (HBIW) via a two-step hydrogenodebenzyl process is carried out according to the following steps:

[0020] Step 1: Debenzylation: In a reactor, hexabenzylhexaazaisowrutzane, N,N-dimethylformamide, bromobenzene or p-bromotoluene, nitrogen-doped titanium dioxide-supported Pd(OH)2 catalyst, and acetic anhydride are added sequentially. The air in the reactor is replaced with hydrogen, and hydrogen is introduced. The reaction is carried out at 0.4-0.5 MPa and 25-40℃ for 20-24 hours. After the HBIW hydrogenolysis reaction is completed, the hydrogen in the reactor is discharged and the mixture is filtered. The filter cake is washed with ethanol and dried in a forced-air oven at 100-110℃ for 2-3 hours to obtain a gray solid containing the target product tetraacetyldibenzylhexaazaisowrutzane (TADBIW) and the catalyst.

[0021] The second step, debenzylation: The gray solid obtained from the first step of debenzylation, acetic acid, nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, and water are added sequentially to the reactor. The air in the reactor is replaced with hydrogen, and hydrogen is introduced. The reaction is carried out under reaction conditions of 1.4-1.5 MPa and 40-60℃ for 20-24 hours. The product obtained after hydrogenolysis of TADBIW is tetraacetylhexaazaisowrutzane (TAIW), which is dissolved in the reaction solvent. After filtering the catalyst, the filtrate is distilled or purified to obtain tetraacetylhexaazaisowrutzane (TAIW).

[0022] Furthermore, the feed ratio of hexabenzylhexaazaisowulzane, N,N-dimethylformamide, bromobenzene or p-bromotoluene, the nitrogen-doped titanium dioxide-supported Pd(OH)2 catalyst added in the first step, acetic anhydride, acetic acid, the nitrogen-doped titanium dioxide-supported Pd(OH)2 catalyst added in the second step, and water is 15g:127mL:0.3mL:0.2g:21mL:127mL:0.2g:18mL.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1) The nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst prepared according to the present invention introduces defect sites and nitrogen species in the nitrogen doping process during the preparation of the nitrogen-doped titanium dioxide support, which is beneficial to better disperse metallic palladium. Therefore, the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst has good stability in the reaction and can be reused multiple times.

[0025] 2) The nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst prepared according to the present invention has excellent acid resistance and a mesoporous structure. The mesoporous structure can reduce the particle size of Pd, thereby increasing the specific surface area of ​​the catalyst and improving the reaction activity. On the other hand, TiO2 and Pd have a strong interaction, and nitrogen doping strengthens this interaction.

[0026] 3) The nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst prepared in this invention has a surfactant added, which not only increases the electron density of Pd, but also improves the dispersion of PdNPs, and exhibits excellent catalytic performance in hydrogenation reaction.

[0027] 4) The nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst prepared in this invention is applied to the preparation of tetraacetylhexaazaisowurtzite (TAIW) from hexabenzylhexaazaisowurtzite (HBIW) via a two-step hydrogen debenzylation reaction. The yield of the two-step debenzylation reaction is high and the catalyst has good stability.

[0028] 5) In the method for producing TADBIW by hydrogen debenzylation of HBIW described in this invention, the bromobenzene auxiliary agent is replaced with p-bromotoluene, which can further improve the yield of TADBIW. Attached Figure Description

[0029] Figure 1 These are the XRD patterns of the catalysts prepared in Examples 1, 10, and 11. Detailed Implementation

[0030] The technical solution of the present invention will be described in more detail below with reference to the embodiments. The scope of protection of the present invention is not limited to the specific embodiments described below.

[0031] Unless otherwise specified in the embodiments of this invention, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained through conventional technical means or commercially available.

[0032] Example 1

[0033] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then, slowly add 0.2020 mL of pyrrole and stir for 24 h. Centrifuge and dry in a 110 °C oven for 6 h. Afterward, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 400 °C for 2 h at a heating rate of 5 °C / min. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-5% N-400-2.

[0034] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a 50 °C water bath. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 5 min and shake well to obtain solution A.

[0035] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 70mL of deionized water and stir in a 70℃ water bath for 10min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 5h after the addition is complete. Then adjust the pH to 11 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter the solution and dry it in a vacuum drying oven at 110℃ for 8h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0036] Example 2

[0037] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then, slowly add 0.2350 mL of pyridine and stir for 24 h. Centrifuge and dry in a 110 °C oven for 6 h. Finally, calcine in a muffle furnace at a heating rate of 4 °C / min. After that, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 300 °C for 2 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-5%N-300-2.

[0038] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a water bath at 65 °C. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 8 min and shake well to obtain solution A.

[0039] (3) Weigh 1.9 g of the support using a weighing balance and place it in a 150 mL beaker. Add 80 mL of deionized water and stir in a 70 °C water bath for 13 min to ensure homogeneity. Slowly add 2 mL of solution A obtained in step (2) dropwise to the beaker containing deionized water and the support. Continue stirring for 5 h after the addition is complete. Then adjust the pH to 12 using sodium hydroxide solution and continue stirring for 2 h. After turning off the heating, continue stirring for 2 h. Finally, filter the solution and dry it at 100 °C for 10 h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 5 wt%.

[0040] Example 3

[0041] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then slowly add 0.3640 g of 1,3,5-tris(4-aminophenyl)benzene and stir for 24 h. Centrifuge and dry in a 120 °C oven for 6 h. Finally, calcine in a muffle furnace at a heating rate of 3 °C / min. Afterward, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 350 °C for 2 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-5%N-350-2.

[0042] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a water bath at 60 °C. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 7 min and shake well to obtain solution A.

[0043] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 75mL of deionized water and stir in a 70℃ water bath for 10min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 5h after the addition is complete. Then adjust the pH to 11 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 110℃ for 8h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0044] Example 4

[0045] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then slowly add 0.0611 g of melamine and stir for 24 h. Centrifuge and dry in a 110 °C oven for 6 h. Finally, calcine in a muffle furnace at a heating rate of 5 °C / min. After that, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 450 °C for 2 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-5% N-450-2.

[0046] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a water bath at 60 °C. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 6 min and shake well to obtain solution A.

[0047] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 60mL of deionized water and stir in a 65℃ water bath for 15min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 5h after the addition is complete. Then adjust the pH to 13 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 110℃ for 7h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0048] Example 5

[0049] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then slowly add 0.2125 g of L-glutamine and stir for 24 h. Centrifuge and dry in a 110 °C oven for 7 h. Finally, calcine in a muffle furnace at a heating rate of 5 °C / min. After that, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 500 °C for 2 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-5%N-500-2.

[0050] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a 60 °C water bath. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 10 min and shake well to obtain solution A.

[0051] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 70mL of deionized water and stir in a 60℃ water bath for 10min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 7h after the addition is complete. Then adjust the pH to 12 using sodium hydroxide solution and continue stirring for 3h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 110℃ for 10h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0052] Example 6

[0053] (1) Add 20 mL of tetraisobutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then, slowly add 0.2660 mL of pyrrole and stir for 24 h. Centrifuge and dry in a 110 °C oven for 8 h. Finally, calcine in a muffle furnace at a heating rate of 5 °C / min. After that, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 400 °C for 1 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-5%N-400-1.

[0054] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a water bath at 65 °C. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 10 min and shake well to obtain solution A.

[0055] (3) Weigh 1.85g of the support using a weighing balance and place it in a 150mL beaker. Add 75mL of deionized water and stir in a 65℃ water bath for 15min to ensure homogeneity. Slowly add 3mL of solution A obtained in step (2) to the beaker containing deionized water and the support. After the addition is complete, continue stirring for 5h. Then, adjust the pH to 11 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 110℃ for 6h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0056] Example 7

[0057] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then, slowly add 0.0470 mL of pyridine and stir for 24 h. Centrifuge and dry in a 120 °C oven for 6 h. Finally, calcine in a muffle furnace at a heating rate of 3 °C / min. After that, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 400 °C for 3 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-1%N-400-3.

[0058] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a 60 °C water bath. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 10 min and shake well to obtain solution A.

[0059] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 70mL of deionized water and stir in a 70℃ water bath for 15min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 5h after the addition is complete. Then adjust the pH to 13 using sodium hydroxide solution and continue stirring for 2h. After turning off the heating, continue stirring for 3h. Finally, filter and dry at 100℃ for 6h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0060] Example 8

[0061] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then slowly add 0.0728 g of 1,3,5-tris(4-aminophenyl)benzene and stir for 24 h. Centrifuge and dry in a 100 °C oven for 8 h. Finally, calcine in a muffle furnace at a heating rate of 5 °C / min. Afterward, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 400 °C for 4 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-1%N-400-4.

[0062] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a water bath at 60 °C. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 8 min and shake well to obtain solution A.

[0063] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 60mL of deionized water and stir in a 65℃ water bath for 10min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 6h after the addition is complete. Then adjust the pH to 12 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 110℃ for 8h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0064] Example 9

[0065] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then slowly add 0.03666 g of melamine and stir for 24 h. Centrifuge and dry in a 100 °C oven for 8 h. Finally, calcine in a muffle furnace at a heating rate of 4 °C / min. After that, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 450 °C for 3 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is denoted as TiO2-3%N-450-3.

[0066] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a 60 °C water bath. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 10 min and shake well to obtain solution A.

[0067] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 70mL of deionized water and stir in a 60℃ water bath for 15min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 5h after the addition is complete. Then adjust the pH to 12 using sodium hydroxide solution and continue stirring for 3h. After turning off the heating, continue stirring for 2h. Finally, filter and dry at 110℃ for 6h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0068] Example 10

[0069] (1) Weigh 2g of sodium dodecylbenzenesulfonate, add it to 150mL of anhydrous ethanol and stir until completely dissolved. Then add 10mL of tetrabutyl titanate, followed by 0.1820g of 1,3,5-tris(4-aminophenyl)benzene. Stir for 24h, centrifuge, and dry in a 100℃ oven for 8h. Finally, calcine in a muffle furnace at a heating rate of 5℃ / min. Afterward, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 400℃ for 2h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support modified with sodium dodecylbenzenesulfonate. This support is designated as TiO2-5%N-SDBS-400-2.

[0070] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a 60 °C water bath. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 10 min and shake well to obtain solution A.

[0071] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 70mL of deionized water and stir in a 60℃ water bath for 15min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 5h after the addition is complete. Then adjust the pH to 12 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 110℃ for 6h to obtain the nitrogen-doped titanium dioxide-supported Pd(OH)2 catalyst modified with sodium dodecylbenzenesulfonate, wherein the Pd loading is 10wt%.

[0072] Example 11

[0073] (1) Weigh 2g of hexadecyltrimethylammonium bromide, add it to 150mL of anhydrous ethanol and stir until completely dissolved. Then add 10mL of tetrabutyl titanate, followed by 0.1820g of 1,3,5-tris(4-aminophenyl)benzene. Stir for 24h, centrifuge, and dry in a 100℃ oven for 8h. Finally, calcine in a muffle furnace at a heating rate of 5℃ / min. Afterward, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 400℃ for 2h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support modified with sodium dodecylbenzenesulfonate. This support is denoted as [reference needed].

[0074] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a 60 °C water bath. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 10 min and shake well to obtain solution A.

[0075] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 70mL of deionized water and stir in a 60℃ water bath for 15min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. After the addition is complete, continue stirring for 5h. Then, adjust the pH to 13 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 110℃ for 6h to obtain the nitrogen-doped titanium dioxide-supported Pd(OH)2 catalyst modified with sodium dodecylbenzenesulfonate, wherein the Pd loading is 10wt%.

[0076] Example 12

[0077] The application of different nitrogen-doped titanium dioxide-supported Pd(OH)2 catalysts prepared in Examples 1 to 9 in the two-step hydrogen debenzylation of hexabenzylhexaazaisowurtzite (HBIW) was investigated.

[0078] In the first step of debenzylation, hexabenzylhexaazaisowrtzine, N,N-dimethylformamide, bromobenzene, nitrogen-doped titanium dioxide-supported Pd(OH)₂ catalyst, and acetic anhydride were added sequentially to a 250 mL reactor at a feed ratio of 15 g: 127 mL: 0.3 mL: 0.2 g: 21 mL. The air in the reactor was replaced five times with hydrogen gas, and the reaction was carried out at 0.5 MPa and 40 °C for 24 h. After the HBIW hydrogenolysis reaction was completed, the hydrogen gas in the reactor was discharged, and the mixture was filtered. The filter cake was washed three times with ethanol. It was then dried in a forced-air oven at 110 °C for 2 h to obtain a gray solid containing the target product tetraacetyldibenzylhexaazaisowrtzine (TADBIW) and the catalyst. In the second step of debenzylation, the gray solid from the first step, 127 mL of acetic acid, 0.2 g of nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, and 18 mL of water were added sequentially to the reactor. The air in the reactor was replaced with hydrogen five times, and hydrogen was introduced. The reaction was carried out at 1.5 MPa and 60 °C for 24 h. The product obtained after hydrogenolysis of TADBIW was tetraacetylhexaazaisowulzane (TAIW), which was dissolved in the reaction solvent. After filtering the catalyst, the filtrate was analyzed by liquid chromatography. The experimental results are shown in Table 1.

[0079] Table 1. Catalytic hydrodebenzylation performance of Pd(OH)₂ / TN catalysts prepared from TN supports calcined at different temperatures and times.

[0080] catalyst First step yield (%) Second step yield (%) Example 1 52 91 Example 2 59 92 Example 3 78 92 Example 4 71 87 Example 5 33 93 Example 6 71 61 Example 7 73 70 Example 8 71 72 Example 9 68 82

[0081] Example 13

[0082] The application of nitrogen-doped titanium dioxide supported Pd(OH)2 catalysts prepared in Examples 3, 10 and 11 in the two-step hydrogen debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12, and the experimental results are shown in Table 2.

[0083] Table 2 Comparison of hydrogenation performance of catalysts with different surfactant-modified supports

[0084] catalyst First step yield (%) Second step yield (%) Example 3 78 92 Example 10 79 93 Example 11 77 95

[0085] Comparative Example 1 (compared to Example 3)

[0086] Comparative Example 1 investigated the reactivity of a commercial titanium dioxide (P25) supported Pd(OH)2 catalyst.

[0087] 8.34 g of PdCl2 was placed in 70 mL of concentrated hydrochloric acid and dissolved by stirring in a 60 °C water bath. The completely dissolved solution was then transferred to a 100 mL volumetric flask, and deionized water was added dropwise to the mark. Finally, the solution was sonicated for 10 min and shaken thoroughly to obtain solution A.

[0088] Weigh 1.8 g of commercial TiO2 support using a weighing balance and place it in a 150 mL beaker. Add 70 mL of deionized water and stir in a 70 °C water bath for 10 min to ensure homogeneity. Slowly add 4 mL of solution A dropwise to the beaker containing deionized water and support. After the addition is complete, continue stirring for 5 h. Then, adjust the pH to 11 using sodium hydroxide solution, continue stirring for 1 h, turn off the heating, and continue stirring for another 1 h. Finally, filter and dry at 110 °C for 8 h. This yields a titanium dioxide-supported Pd(OH)2 catalyst with a Pd loading of 10 wt%.

[0089] The application of the prepared titanium dioxide-supported Pd(OH)2 catalyst in the two-step debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12. The yield of the first debenzylation step was 72%, and the yield of the second debenzylation step was 90%.

[0090] Comparative Example 2 (compared to Example 3)

[0091] Comparative Example 2 investigated the reaction performance of a nitrogen- and fluorine co-doped titanium dioxide supported Pd(OH)2 catalyst.

[0092] (1) Using NaF as the F source, NaF was added to 150 mL of anhydrous ethanol and stirred until completely dissolved. Then, 10 mL of tetrabutyl titanate was added, followed by the slow addition of 0.3640 g of 1,3,5-tris(4-aminophenyl)benzene. The mixture was stirred for 24 h, centrifuged, and repeatedly washed with deionized water. It was then dried in a 110 °C oven for 6 h. Finally, it was calcined in a muffle furnace at 400 °C for 2 h at a heating rate of 5 °C / min. This yielded a nitrogen- and fluorine-doped titanium dioxide support. This support is designated TN-F.

[0093] (2) 8.34 g of PdCl2 was placed in 70 mL of concentrated hydrochloric acid and dissolved by stirring in a 60 °C water bath. The completely dissolved solution was then transferred to a 100 mL volumetric flask, and deionized water was added dropwise to the mark. Finally, the solution was sonicated for 10 min and shaken until homogeneous to obtain solution A. 1.8 g of the support was weighed using a weighing balance and placed in a 150 mL beaker, along with 70 mL of deionized water. The mixture was stirred in a 70 °C water bath for 10 min to ensure homogeneity. 4 mL of solution A was slowly added dropwise to the beaker containing deionized water and the support. After the addition was complete, stirring was continued for 5 h. The pH was then adjusted to 11 using sodium hydroxide solution, and stirring was continued for 1 h. After turning off the heating, stirring was continued for another 1 h. Finally, the mixture was filtered and dried at 110 °C for 8 h. A nitrogen- and fluorine co-doped titanium dioxide-supported Pd(OH)2 catalyst was obtained, with a Pd loading of 10 wt%.

[0094] (3) The application of the prepared nitrogen and fluorine co-doped titanium dioxide supported Pd(OH)2 catalyst in the two-step hydrogen debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12. The yield of the first step debenzylation was 64%, and the yield of the second step debenzylation was 77%.

[0095] Comparative Example 3 (compared to Example 3)

[0096] Comparative Example 3 investigated the reaction performance of a nitrogen- and phosphorus co-doped titanium dioxide supported Pd(OH)2 catalyst.

[0097] (1) Take 2g of TN-400-2 powder prepared in Example 3 and use the equal-volume impregnation method. Mix orthophosphoric acid with 3mL of deionized water evenly and add it dropwise to a petri dish containing TN-400-2 powder. After impregnation for 24h, dry in a 100℃ forced-air oven for 8h. Finally, calcine in a muffle furnace at 400℃ for 2h, with a heating rate of 5℃ / min. This is denoted as TN-P.

[0098] (2) 8.34 g of PdCl2 was placed in 70 mL of concentrated hydrochloric acid and dissolved by stirring in a 60 °C water bath. The completely dissolved solution was then transferred to a 100 mL volumetric flask, and deionized water was added dropwise to the mark. Finally, the solution was sonicated for 10 min and shaken until homogeneous to obtain solution A. 1.8 g of the support was weighed using a balance and placed in a 150 mL beaker, along with 70 mL of deionized water. The mixture was stirred in a 70 °C water bath for 10 min to ensure homogeneity. 4 mL of solution A was slowly added dropwise to the beaker containing deionized water and the support. After the addition was complete, stirring was continued for 5 h. The pH was then adjusted to 11 using sodium hydroxide solution, and stirring was continued for 1 h. After turning off the heating, stirring was continued for another 1 h. Finally, the mixture was filtered and dried at 110 °C for 8 h. A nitrogen- and phosphorus co-doped titanium dioxide-supported Pd(OH)2 catalyst was obtained, with a Pd loading of 10 wt%.

[0099] (3) The application of the prepared nitrogen and phosphorus co-doped titanium dioxide supported Pd(OH)2 catalyst in the two-step hydrogen debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12. The yield of the first step debenzylation was 55%, and the yield of the second step debenzylation was 80%.

[0100] Comparative Example 4 (compared to Example 3)

[0101] Comparative Example 4 investigated the reaction performance of a nitrogen- and sulfur-co-doped titanium dioxide-supported Pd(OH)2 catalyst.

[0102] (1) Using KSCN as the S source, add it to 150 mL of anhydrous ethanol and stir until completely dissolved. Then add 10 mL of tetrabutyl titanate, followed by the slow addition of 0.3640 g of 1,3,5-tris(4-aminophenyl)benzene. Stir for 24 h, centrifuge, and wash repeatedly with deionized water. Dry in a 110 °C oven for 6 h. Finally, calcine in a muffle furnace at 400 °C for 2 h at a heating rate of 5 °C / min. Nitrogen- and fluorine-doped titanium dioxide support is obtained. This support is designated TN-S.

[0103] (2) 8.34 g of PdCl2 was placed in 70 mL of concentrated hydrochloric acid and dissolved by stirring in a 60 °C water bath. The completely dissolved solution was then transferred to a 100 mL volumetric flask, and deionized water was added dropwise to the mark. Finally, the solution was sonicated for 10 min and shaken until homogeneous to obtain solution A. 1.8 g of the support was weighed using a balance and placed in a 150 mL beaker, and 70 mL of deionized water was added. The mixture was stirred in a 70 °C water bath for 10 min until homogeneous. 4 mL of solution A was slowly added dropwise to the beaker containing deionized water and the support. After the addition was complete, stirring was continued for 5 h. Then, the pH was adjusted to 11 using sodium hydroxide solution, and stirring was continued for 1 h. After turning off the heating, stirring was continued for 1 h. Finally, the mixture was filtered and dried at 110 °C for 8 h. A nitrogen- and sulfur-co-doped titanium dioxide-supported Pd(OH)2 catalyst was obtained, in which the Pd loading was 10 wt%.

[0104] (3) The application of the prepared nitrogen and sulfur co-doped titanium dioxide supported Pd(OH)2 catalyst in the two-step hydrogen debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12. The yield of the first step debenzylation was 64%, and the yield of the second step debenzylation was 81%.

[0105] Comparative Example 5 (compared to Example 3)

[0106] Comparative Example 5 investigated the reaction performance of a sulfur-doped titanium dioxide-supported Pd(OH)2 catalyst.

[0107] (1) Using KSCN as the sulfur source, add it to 150 mL of anhydrous ethanol and stir until completely dissolved. Then add 10 mL of tetrabutyl titanate, stir for 24 h, centrifuge, and wash repeatedly with deionized water. Dry in a 110 °C oven for 6 h. Finally, calcine in a muffle furnace at 400 °C for 2 h, with a heating rate of 5 °C / min. This yields a sulfur-doped titanium dioxide support. This support is denoted as TS.

[0108] (2) 8.34 g of PdCl2 was placed in 70 mL of concentrated hydrochloric acid and dissolved by stirring in a 60 °C water bath. The completely dissolved solution was then transferred to a 100 mL volumetric flask, and deionized water was added dropwise to the mark. Finally, the solution was sonicated for 10 min and shaken to obtain solution A. 1.8 g of the support was weighed using a balance and placed in a 150 mL beaker, and 70 mL of deionized water was added. The mixture was stirred in a 70 °C water bath for 10 min to ensure homogeneity. 4 mL of solution A was slowly added dropwise to the beaker containing deionized water and the support. After the addition was complete, stirring was continued for 5 h. Then, the pH was adjusted to 11 using sodium hydroxide solution, and stirring was continued for 1 h. After turning off the heating, stirring was continued for 1 h. Finally, the mixture was filtered and dried at 110 °C for 8 h. A sulfur-doped titanium dioxide-supported Pd(OH)2 catalyst was obtained, in which the Pd loading was 10 wt%.

[0109] (3) The application of the prepared sulfur-doped titanium dioxide supported Pd(OH)2 catalyst in the two-step debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12. The yield of the first debenzylation step was 14%, and the yield of the second debenzylation step was 23%.

[0110] Comparative Example 6 (compared to Example 3)

[0111] Comparative Example 6 investigated the reaction performance of a phosphorus-doped titanium dioxide-supported Pd(OH)2 catalyst.

[0112] (1) Using the equal-volume impregnation method. Orthophosphoric acid was mixed evenly with 3 mL of deionized water and added dropwise to a petri dish containing commercial TiO2 powder. After impregnation for 24 h, it was dried in an 80℃ forced-air oven for 8 h. Finally, it was calcined in a muffle furnace at 400℃ for 2 h, with a heating rate of 5℃ / min. This is denoted as TP.

[0113] (2) 8.34 g of PdCl2 was placed in 70 mL of concentrated hydrochloric acid and dissolved by stirring in a 60 °C water bath. The completely dissolved solution was then transferred to a 100 mL volumetric flask, and deionized water was added dropwise to the mark. Finally, the solution was sonicated for 10 min and shaken to obtain solution A. 1.8 g of the support was weighed using a balance and placed in a 150 mL beaker, and 70 mL of deionized water was added. The mixture was stirred in a 70 °C water bath for 10 min to ensure homogeneity. 4 mL of solution A was slowly added dropwise to the beaker containing deionized water and the support. After the addition was complete, stirring was continued for 5 h. Then, the pH was adjusted to 11 using sodium hydroxide solution, and stirring was continued for 1 h. After turning off the heating, stirring was continued for 1 h. Finally, the mixture was filtered and dried at 110 °C for 8 h. A phosphorus-doped titanium dioxide-supported Pd(OH)2 catalyst was obtained, in which the Pd loading was 10 wt%.

[0114] (3) The application of the prepared phosphorus-doped titanium dioxide supported Pd(OH)2 catalyst in the two-step debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12. The yield of the first debenzylation step was 23%, and the yield of the second debenzylation step was 33%.

[0115] Comparative Example 7

[0116] Comparative Example 7 investigated the effect of solvent on the performance of the catalyst in the HBIW hydrodebenzylation reaction.

[0117] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then slowly add 0.3640 g of 1,3,5-tris(4-aminophenyl)benzene and stir for 24 h. Centrifuge and dry in a 120 °C oven for 6 h. Finally, calcine in a muffle furnace at a heating rate of 3 °C / min. Afterward, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 350 °C for 2 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is designated as TN-350-2.

[0118] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a 60 °C water bath. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 10 min and shake well to obtain solution A.

[0119] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 75mL of deionized water and stir in a 65℃ water bath for 15min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 6h after the addition is complete. Then adjust the pH to 11 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 120℃ for 8h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0120] (4) The application of the prepared nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst in the two-step hydrogen debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12, except that the solvent for the first step of debenzylation was replaced with N,N-dimethylacetamide. The yield of the first step of debenzylation was 0%, and the yield of the second step of debenzylation was 70%.

[0121] Comparative Example 8

[0122] Comparative Example 8 investigated the effect of the additive on the catalyst's performance in the HBIW hydrodebenzyl reaction.

[0123] (1) Add 20 mL of tetrabutyl titanate to 300 mL of anhydrous ethanol and stir until homogeneous. Then slowly add 0.3640 g of 1,3,5-tris(4-aminophenyl)benzene and stir for 24 h. Centrifuge and dry in a 120 °C oven for 6 h. Finally, calcine in a muffle furnace at a heating rate of 3 °C / min. Afterward, grind with an agate mortar to obtain a light yellow powder. Finally, place the light yellow powder in a muffle furnace and calcine at 350 °C for 2 h. Cool to room temperature to obtain a nitrogen-doped titanium dioxide support, which is designated as TN-350-2.

[0124] (2) Dissolve 8.34 g of PdCl2 in 70 mL of concentrated hydrochloric acid by stirring in a 60 °C water bath. Then transfer the completely dissolved solution to a 100 mL volumetric flask and add deionized water to the mark. Finally, sonicate for 10 min and shake well to obtain solution A.

[0125] (3) Weigh 1.8g of the support using a weighing balance and place it in a 150mL beaker. Add 75mL of deionized water and stir in a 65℃ water bath for 15min to ensure homogeneity. Slowly add 4mL of solution A obtained in step (2) to the beaker containing deionized water and the support. Continue stirring for 6h after the addition is complete. Then adjust the pH to 11 using sodium hydroxide solution and continue stirring for 1h. After turning off the heating, continue stirring for 1h. Finally, filter and dry at 120℃ for 8h to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, in which the Pd loading is 10wt%.

[0126] (4) The application of the prepared nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst in the two-step hydrogen debenzylation of hexabenzylhexaazaisowulzane (HBIW) was investigated. The application process and conditions were the same as in Example 12, except that the bromobenzene in the first step of debenzylation was replaced with p-bromotoluene. The yield of the first step of debenzylation was 81%, and the yield of the second step of debenzylation was 95%.

Claims

1. The application of a nitrogen-doped titanium dioxide-supported Pd(OH)₂ catalyst in the two-step hydrogenolysis of hexabenzylhexaazaisowrutzane to prepare tetraacetylhexaazaisowrutzane, characterized in that: The preparation method of the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst includes the following specific steps: (1) Preparation of nitrogen-doped titanium dioxide support: Titanium-containing organic matter and anhydrous ethanol were mixed, and then a certain amount of nitrogen-containing organic matter was added. The mixture was stirred continuously for 22-24 hours, centrifuged, and dried in a forced-air oven at 100-120 ℃ for 6-8 hours. After that, the mixture was ground to obtain powder. Finally, the powder was placed in a muffle furnace and calcined at 350 ℃ for 2 hours. After cooling to room temperature, nitrogen-doped titanium dioxide support was obtained. This support is denoted as TiO2-mN-350-2, where 350 represents the calcination temperature, 2 represents the calcination time, and m represents the molar percentage of nitrogen element in titanium element, m=1%-5%, and m is calculated according to the feed ratio. The nitrogen-containing organic matter is 1,3,5-tris(4-aminophenyl)benzene. (2) Dissolve PdCl2 in hydrochloric acid to obtain solution A; (3) Add the nitrogen-doped titanium dioxide support and deionized water obtained in step (1) to the container and stir in a water bath at 60-70 ℃ for 10-20 min to make it evenly mixed; take the solution A obtained in step (2) and slowly add it dropwise to the container containing the mixture, and continue stirring for 5-7 h; then use an alkaline solution to adjust the pH to > 10, continue stirring for 1-3 h, turn off the heating and continue stirring for 1-3 h; finally, filter, and the obtained sample is dried under vacuum to obtain the nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, so that the loading of Pd = mass of Pd / (mass of Pd + mass of nitrogen-doped titanium dioxide support) × 100% = 10wt%, where the mass of Pd refers to the mass of Pd element contained in the added solution A.

2. The application as described in claim 1, characterized in that: In step (1), the titanium-containing organic compound is at least one of tetraethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate.

3. The application as described in claim 1, characterized in that: In step (1), the volume ratio of the titanium-containing organic matter to anhydrous ethanol is 1:10-30.

4. The application as described in claim 1, characterized in that: In step (1), m = 5%.

5. The application as described in claim 1, characterized in that: In step (1), the dispersant is first dissolved in anhydrous ethanol, and then titanium-containing organic matter is added. The dispersant is selected from one of triethoxysilane, silane, polyethylene glycol, sodium dodecylbenzenesulfonate, and hexadecyltrimethylammonium bromide. The mass-volume ratio of the dispersant to the titanium-containing organic matter is (1-3) g: 10 mL.

6. The application as described in claim 1, characterized in that: In step (3), the alkaline solution is an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, or ammonia; the vacuum drying temperature is 80-110℃, and the vacuum drying time is 6-12h.

7. The application as described in any one of claims 1-6, characterized in that: The preparation of tetraacetylhexaazaisowrutzane from hexabenzylhexaazaisowrutzane via a two-step hydrogenodebenzyl process is specifically carried out according to the following steps: Step 1: Debenzylation: Hexabenzylhexaazaisowrutzane, N,N-dimethylformamide, bromobenzene or p-bromotoluene, nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, and acetic anhydride are added sequentially to a reactor. The air in the reactor is replaced with hydrogen, and hydrogen is introduced. The reaction is carried out for 20-24 hours under the reaction conditions of 0.4-0.5 MPa and 25-40℃. After the HBIW hydrogenolysis reaction is completed, the hydrogen in the reactor is discharged and the mixture is filtered. The filter cake is washed with ethanol and dried in a forced-air oven at 100-110 ℃ for 2-3 hours to obtain a gray solid containing the target product tetraacetyldibenzylhexaazaisowrutzane and the catalyst. The second step is debenzylation: The gray solid obtained from the first step of debenzylation, acetic acid, nitrogen-doped titanium dioxide supported Pd(OH)2 catalyst, and water are added sequentially to the reactor. The air in the reactor is replaced with hydrogen, and hydrogen is introduced. The reaction is carried out for 20-24 hours under the reaction conditions of 1.4-1.5 MPa and 40-60℃. The product obtained after hydrogenolysis of tetraacetyldibenzylhexaazaisowrutzane is tetraacetylhexaazaisowrutzane, which is dissolved in the reaction solvent. After filtering the catalyst, the filtrate is distilled or purified to obtain tetraacetylhexaazaisowrutzane.

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