Three-dimensional ordered macroporous nitrogen-doped carbon-loaded PdM catalyst and application thereof in TADBIW hydrogenolysis

Abstract

The invention discloses a three-dimensional ordered macroporous nitrogen-doped carbon loaded PdM catalyst and an application of the three-dimensional ordered macroporous nitrogen-doped carbon loaded PdM catalyst in hydrogenolysis of TADBIW. The preparation method comprises the following steps: filling a precursor of ZIF-8 and M (M is Cu, Fe, Ni, Co or Mn) salt between orderly arranged polystyrene templates, inducing coordination and crystallization growth of the ZIF-8 through double solvents to form ZIF-8, carrying out high-temperature calcination to remove the templates and convert the templates into a nitrogen-doped carbon phase, and loading Pd to obtain the PdM / DOM-NC catalyst with a three-dimensional ordered macroporous structure. The catalyst is uniform in particle size, uniform in dispersion and stable in structure. Benefited from the synergistic effect of a unique three-dimensional ordered macroporous structure and bimetal, in the hydrogenolysis reaction process of TADBIW, the catalyst shows activity far superior to that of a commercial Pd / C catalyst, the reaction efficiency is improved, and the use amount of precious metal is reduced, so that the production cost is effectively reduced, and the catalyst has a relatively good application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of catalyst applications, and particularly relates to a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon and its application in the hydrogenolysis of TADBIW. Background Art

[0002] CL-20 (hexanitrohexaazaisowurtzitane) has become a research hotspot in the field of energetic materials due to its excellent explosive performance and energy output. In the currently reported industrial production process of CL-20, it is inevitable to use a noble metal Pd catalyst to promote the conversion of the intermediate tetraacetyldibenzylhexaazaisowurtzitane (TADBIW) to tetraacetylhexaazaisowurtzitane (TAIW). However, the traditional Pd catalyst used in this process has defects such as low catalytic efficiency, poor cyclic stability, and easy loss and aggregation of the Pd component. The low catalytic economy greatly limits the large-scale production of CL-20. In recent years, related research work has basically focused on the development of new carriers (CN112844439A, CN111644194A) and doped transition metals (CN106946894A), but problems such as high catalyst dosage and long reaction time have not been solved. Therefore, there is an urgent need to develop a stable and efficient catalyst to replace the Pd / C catalyst used in the traditional production process to reduce the production cost of CL-20.

[0003] Catalysts with a microporous structure have a relatively large specific surface area, but the adsorption and desorption of larger substrates on the catalytic active centers during the catalytic process will be restricted by the microporous structure. Therefore, applying a catalyst with a macroporous structure in the process of macromolecular catalysis can enhance the mass transfer rate and substrate accessibility, thereby improving the catalytic reaction efficiency. Bimetallic nanoparticles are composed of two different metals. The synergistic effect, electronic effects such as charge transfer, smaller size, and better dispersion between the two metals make them highly regarded as high-performance catalytic materials. Therefore, for reactions catalyzed by noble metals, doping with relatively inexpensive transition metals in the form of alloy phases or particle mixtures will bring great variability to aspects such as the composition, structure, and properties of the catalyst, and may reduce the usage amount of noble metals.

[0004] The macroporization of the catalyst support and metal doping have been applied in many catalytic systems and achieved expected results, but there is no relevant report on the hydrogenolysis reactant of TADBIW. As an organic macromolecule, the mass transfer and diffusion efficiency of TADBIW in the catalytic system will have a greater impact on the reaction activity. Designing a catalyst with a macroporous structure for this substrate may greatly improve the efficiency of its hydrogenolytic debenzylation. Doping transition metals such as Cu, Fe, Ni, Co, or Mn into the catalyst and forming a synergistic effect with Pd are expected to reduce the usage amount of Pd. Summary of the Invention

[0005] The object of the present invention is to provide a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon and its application in the hydrogenolysis of TADBIW, aiming to develop a new type of hydrogenolytic debenzylation industrial catalyst and reduce the production cost of CL-20 in view of the problems of low catalytic efficiency and high noble metal consumption of the catalyst in the hydrogenolysis reaction of TADBIW.

[0006] To achieve the object of the above invention, the present invention adopts the following technical solutions:

[0007] Precursors of zeolitic imidazolate framework (ZIF-8) and salts of M (where M is Cu, Fe, Ni, Co or Mn) are filled between orderly arranged polystyrene templates (PS), and they are induced to coordinate and crystallize to grow into ZIF-8 through double solvents, and then the templates are removed by high-temperature calcination and transformed into a nitrogen-doped carbon phase. After loading Pd, a PdM / DOM-NC catalyst with a three-dimensionally ordered macroporous structure is obtained.

[0008] A preparation method of a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon includes the following steps:

[0009] 1) Synthesize PS microspheres by emulsion polymerization

[0010] Wash styrene with 10 wt.% NaOH solution and deionized water. Measure 32.5 mL of the washed styrene and add it to a 500 mL three-necked flask, and mix it with 250 mL of deionized water and 1.25 g of polyvinylpyrrolidone (PVP). Bubble nitrogen for 20 - 25 min, stir the mixture at 70 - 75 °C under a N2 atmosphere for 30 - 40 min, then add 25 mL of an aqueous solution containing 0.5 g of K2S2O8 as an initiator, and stir at 80 - 88 °C under the protection of a N2 atmosphere at a rotation speed of 500 - 600 rpm for 24 - 28 h. A PS microsphere emulsion suspension is obtained by the polymerization reaction. Centrifuge the suspension at a rotation speed of 8000 - 1000 rpm, collect the white precipitate and wash it with deionized water, and vacuum dry it at 60 - 70 °C for 10 - 12 h to obtain three-dimensionally ordered PS microspheres.

[0011] Among them, the purpose of washing styrene is to remove the inhibitor in the styrene reagent. The initiator can also be one of Na2S2O8 and (NH4)2S2O8 in addition to K2S2O8. The synthesized PS microspheres have a particle size of 150 ± 10 nm.

[0012] 2) Preparation of a macroporous support and loading of metal M (where M is Cu, Fe, Ni, Co or Mn)

[0013] Dissolve 4.08 g of Zn(NO3)2·6H2O, 3.38 g of 2-methylimidazole and 200 mg of metal M (M is Cu, Fe, Ni, Co or Mn) salt in 10 mL of methanol solution to obtain solution A;

[0014] Place the PS microspheres (as a template) and solution A in a flask, degas under vacuum for 10 - 15 min and then let stand for 1 - 1.2 h. Filter and collect product A and dry it at 50 - 60 °C for 7.5 - 8.5 h. Then place product A in a flask, add a methanol / ammonia water mixed solution, degas under vacuum for 3 - 5 min, restore normal pressure and let stand at room temperature for 24 - 28 h. Filter and collect product B and dry it at room temperature for 18 - 24 h. Then put product B into a tube furnace, introduce an inert gas at a rate of 38 - 42 mL / min, heat up to 400 - 420 °C at a rate of 9 - 11 °C / min and calcine for 3.8 - 4.2 h, then continue to heat up to 950 - 1050 °C at a rate of 4.8 - 5.2 °C / min and calcine for 1 - 1.1 h. Cool to room temperature and take out to obtain the three-dimensional ordered macroporous nitrogen-doped carbon material M / DOM-NC loaded with metal M.

[0015] Among them, the optimal molar ratio of Zn(NO3)2·6H2O to 2-methylimidazole is 1:3. The metal M salt is one of sulfate, nitrate, acetate, chloride containing metal M. The two vacuum degassing operations are to strengthen the entry of Zn salt, organic ligand or methanol / ammonia water mixed solution into the gaps of the PS microsphere template. The optimal volume ratio of methanol to ammonia water in the methanol / ammonia water mixed solution is 3:4, and its function is deprotonation and promoting crystal growth. The inert gas can be one of nitrogen and argon. The calcination at 400 - 420 °C is to remove the PS template, and the calcination at 950 - 1050 °C is to pyrolyze ZIF-8.

[0016] 3) Impregnation reduction method for loading metal Pd

[0017] Mix M / DOM-NC with deionized water and disperse it evenly by ultrasonic wave. Stir vigorously at 75 - 85 °C at a rotation speed of 600 - 800 rpm to obtain a carrier suspension. Adjust the pH of the suspension to 11 - 12 with an alkali solution. Dissolve the Pd salt in deionized water and then slowly add it dropwise to the carrier suspension. Stir vigorously at a rotation speed of 600 - 800 rpm for 8 - 9 h. After the suspension cools, filter it, wash it several times and dry it at 60 - 65 °C for 12 - 18 h. Place the product in a porcelain boat and put it into a tube furnace. Introduce H2 at a rate of 38 - 42 mL / min, heat up to 200 - 220 °C at a rate of 4.8 - 5.2 °C / min and reduce it at this temperature for 1 - 1.1 h. Cool and take out to obtain the PdM / DOM-NC catalyst.

[0018] Among them, the alkali solution is one of sodium bicarbonate, sodium hydroxide, and ammonia water. The Pd salt is one of palladium nitrate, palladium chloride, chloropalladic acid, sodium tetrachloropalladate, and tetraammine palladium sulfate. The Pd loading of the obtained PdM / DOM-NC catalyst can be controlled by the amount of Pd salt added, and can be 1%, 2%, 5%, 10%, etc.

[0019] The PdM / DOM-NC catalyst with a three-dimensional ordered macroporous structure provided by the present invention can be applied to the process of hydrogenolysis of benzyl group from macromolecular TADBIW, improving the problem of low catalytic efficiency of traditional microporous supports. The specific steps are as follows:

[0020] Weigh a certain amount of TADBIW and place it in a reactor. Add a mixed solution of glacial acetic acid and deionized water as the reaction solvent to the reactor, and then add a certain mass of PdNi / DOM-NC catalyst. After introducing nitrogen and checking its airtightness, switch to hydrogen. Start stirring and heat up to the reaction temperature. After the reaction is completed, filter the catalyst, rotary evaporate the reaction solution, and dry to obtain the target product. The catalyst is washed to neutrality and then dried for recovery.

[0021] The mass ratio of the catalyst to TADBIW is preferably 0.001 - 0.01, and optimally 0.004. Among them, the mass of the catalyst is calculated based on the mass of the Pd component, and the added mass of the catalyst can be obtained according to the actual loading.

[0022] The reaction temperature for catalysis can be between 40 and 60 °C, and optimally 50 °C; the reaction time is 80 - 300 min, and optimally 100 min; the washing liquid can be one of acetone, ethanol, and deionized water.

[0023] The above hydrogenolysis reaction formula is as follows:

[0024]

[0025] The present invention adopts the above technical solutions, uses nitrogen-doped carbon (NC) with a three-dimensional ordered macroporous (DOM) structure as a support to load the bimetal palladium PdM (M is Cu, Fe, Ni, Co, or Mn). Among them, DOM-NC is obtained by pyrolyzing on the basis of synthesizing zeolitic imidazolate framework (ZIF-8) with polystyrene (PS) microspheres as a template. The in-situ loading of metal M is realized during the filling and growth crystallization process of the ZIF-8 precursor, and the loading of metal Pd is realized by the impregnation reduction method.

[0026] The present invention has the following beneficial effects:

[0027] The catalyst of the present invention has a unique three-dimensional ordered macroporous structure. The highly interconnected macropores enhance the process of TADBIW diffusing to the Pd active sites, greatly accelerating the reaction rate. At the same time, the DOM-NC support improves the dispersion of the supported Pd particles, and the heteroatoms play an anchoring role for Pd. The doping of metal M (M is Cu, Fe, Ni, Co or Mn) improves the electronic structure of Pd, and the synergistic effect of the bimetals enables the catalyst to efficiently promote the hydrogenolysis reaction of TADBIW even at a lower Pd dosage. The catalyst exhibits good activity, selectivity and stability. After several cycles, no obvious loss and aggregation of Pd occur, and the activity does not decrease significantly.

[0028] The present invention combines the synergistic effect generated by bimetal doping with a macroporous support to prepare a PdM bimetal catalyst, breaking through the limitation that the lowest mass ratio of Pd:TADBIW in the reported catalytic hydrogenolysis of TADBIW is 0.004, successfully reducing the Pd dosage and improving the catalytic economy.

[0029] The catalyst of the present invention has uniform particle size, uniform dispersion and stable structure. Benefiting from the unique three-dimensional ordered macroporous structure and the synergistic effect of the bimetals, during the hydrogenolysis reaction of TADBIW, this catalyst exhibits far higher activity than the commercial Pd / C catalyst, improving the reaction efficiency, reducing the noble metal dosage, thus effectively reducing the production cost and having good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is the 2%-PdNi / DOM-NC catalyst prepared in Example 1.

[0031] Figure 2 It is the XRD spectra of three bimetal three-dimensional ordered macroporous catalysts prepared in Examples 1, 3 and 4. DETAILED DESCRIPTION OF THE INVENTION

[0032] The technical solution of the present invention will be further explained and illustrated below through specific examples. In the present invention, unless otherwise specified, all raw materials are commercially available products.

[0033] Example 1

[0034] Preparation of PdNi / DOM-NC Catalyst

[0035] 1) Preparation of PS microspheres

[0036] Wash styrene with 10 wt.% NaOH solution and deionized water. Measure 32.5 mL of the washed styrene and add it to a 500 mL three-necked flask. Mix it with 250 mL of deionized water and 1.25 g of PVP. After bubbling nitrogen for 20 min, stir the mixture at 70 °C under a N2 atmosphere for 30 min. Add 25 mL of an aqueous solution containing 0.5 g of K2S2O8 and stir at 85 °C under a N2 atmosphere at a rotation speed of 500 rpm for 24 h to obtain a PS microsphere suspension. Centrifuge the suspension at a rotation speed of 8000 rpm, collect the white precipitate, wash it with deionized water, and dry it in vacuum at 60 °C for 12 h to obtain PS microspheres.

[0037] 2) Preparation of Ni / DOM-NC support

[0038] Dissolve 4.08 g of Zn(NO3)2·6H2O, 3.38 g of 2-methylimidazole, and 200 mg of Ni(NO3)2·6H2O in 10 mL of methanol solution to obtain solution A;

[0039] Take 3 g of PS microsphere template and place it in a flask. Add solution A to the flask. After vacuum degassing for 10 min, let it stand for 1 h. Filter and collect product A and dry it at 50 °C for 8 h. Then place product A in a flask, add a mixed solution of 15 mL of methanol and 20 mL of ammonia water, vacuum degas for 3 min, restore normal pressure, and let it stand at room temperature for 24 h. Filter and collect product B and dry it at room temperature for 12 h. Then place product B in a tube furnace, introduce an inert gas (40 mL / min), heat it to 400 °C at a rate of 10 °C / min, calcine for 4 h, continue to heat it to 1000 °C at a rate of 5 °C / min and calcine for 1 h, cool it to room temperature and take it out to obtain the Ni / DOM-NC support.

[0040] 3) Preparation of PdNi / DOM-NC catalyst

[0041] Mix 200 mg of Ni / DOM-NC support with 30 mL of deionized water in a flask. Sonicate to fully disperse the support, and stir vigorously at 80 °C with a rotation speed of 600 - 800 rpm. Adjust the pH of the suspension to 11.5 with an alkaline solution. Dissolve 15 mg of palladium nitrate dihydrate in 10 mL of deionized water and slowly add it dropwise to the support suspension. Stir vigorously at 600 - 800 rpm for 8 h. After the suspension cools, filter it, wash it several times, and then dry it at 60 °C for 12 h. Place the material in a porcelain boat, put it into a tubular furnace, introduce H2 (40 mL / min), heat it to 200 °C at a rate of 5 °C / min and reduce it at this temperature for 1 h. Take it out after cooling to obtain the PdNi / DOM-NC catalyst (the measured Pd loading is 2%, denoted as 2%-PdNi / DOM-NC. In the actual operation process, an excessive amount needs to be prepared, that is, the mass of Pd metal: the mass of M / DOM-NC support should be greater than 2%).

[0042] Hydrogenolysis of TADBIW

[0043] Weigh 1 g of TADBIW and place it in a reaction kettle. Add a mixed solution of 20 mL of glacial acetic acid and 5 mL of deionized water as the reaction solvent into the kettle. Then add 125 mg of PdNi / DOM-NC catalyst. Introduce nitrogen and check its airtightness, and then switch to hydrogen. Start stirring and heat up to 50 °C. After reacting for 100 min, filter the catalyst, rotary evaporate the reaction solution, and dry it to obtain the target product. The catalyst is washed with ethanol until neutral and then dried for recycling.

[0044] Example 2

[0045] Do not add Ni salt as a doping component (i.e., do not add 200 mg of Ni(NO3)2·6H2O). Other operations and parameters are the same as those in Example 1. The prepared catalyst is 2%-Pd / DOM-NC.

[0046] Example 3

[0047] Change the 200 mg of Ni(NO3)2·6H2O added in Example 1 to 277 mg of iron nitrate nonahydrate. Other operations and parameters are the same as those in Example 1. The prepared catalyst is 2%-PdFe / DOM-NC.

[0048] Example 4

[0049] Change the 200 mg of Ni(NO3)2·6H2O added in Example 1 to 166 mg of copper nitrate trihydrate. Other operations and parameters are the same as those in Example 1. The prepared catalyst is 2%-PdCu / DOM-NC.

[0050] Example 5

[0051] Change the catalyst dosage of the TADBIW hydrogenolysis reaction in Example 1 to 200 mg, and keep other parameters and operations the same as those in Example 1.

[0052] Example 6

[0053] Change the catalyst dosage of the TADBIW hydrogenolysis reaction in Example 2 to 200 mg, and keep other parameters and operations the same as those in Example 2.

[0054] Example 7

[0055] Change the catalyst dosage of the TADBIW hydrogenolysis reaction in Example 3 to 200 mg, and keep other parameters and operations the same as those in Example 3.

[0056] Example 8

[0057] Change the catalyst dosage of the TADBIW hydrogenolysis reaction in Example 4 to 200 mg, and keep other parameters and operations the same as those in Example 4.

[0058] Comparative Example 1

[0059] 1) Prepare PS microspheres: The steps are the same as those in Example 1.

[0060] 2) Prepare NC support

[0061] 0.45 g of Zn(NO3 )2 ·6H2O and 3.73 g of 2-methylimidazole are dissolved in 50 mL of methanol. The mixed solution is placed in a hydrothermal autoclave and reacted at 150 °C for 12 h. After cooling, it is centrifuged and collected, washed several times with deionized water, and dried at 80 °C for 12 h. The material is placed in a tubular furnace, an inert gas (40 mL / min) is introduced, heated to 400 °C at a rate of 10 °C / min, calcined for 4 h, then heated to 1000 °C at a rate of 5 °C / min and continued to be calcined for 1 h, and taken out after cooling to room temperature.

[0062] 3) Prepare 2%-Pd / NC catalyst

[0063] Except that the support is NC with a microporous structure, other parameters and operations are the same as those in Example 1.

[0064] 4) Hydrogenolysis of TADBIW

[0065] The operations and parameters are the same as those in Example 1.

[0066] Comparative Example 2

[0067] Change the catalyst dosage of the TADBIW hydrogenolysis reaction in Comparative Example 1 to 200 mg, and keep other parameters and operations the same as those in Comparative Example 1.

[0068] Comparative Example 3

[0069] Commercially available 5% Pd / C catalyst, the amount of catalyst added in the hydrogenolysis of TADBIW was 50 mg, and other parameters and conditions were the same as those in Example 1.

[0070] Comparative Example 4

[0071] The amount of catalyst added in the hydrogenolysis of TADBIW was 80 mg, and other parameters and conditions were the same as those in Comparative Example 3.

[0072] The catalysts in Examples 1 to 8 and Comparative Examples 1 to 4 were used for the hydrogenolytic debenzylation of TADBIW, and the reaction conditions, catalyst parameters and yields are shown in Table 1.

[0073] Table 1 Hydrogenolysis of TADBIW

[0074]

[0075]

[0076] Examples 1 to 8 show that: at a relatively large catalyst dosage (Pd: TADBIW = 4 wt.‰), Pd and bimetallic PdNi, PdCu, PdFe, etc. supported on three-dimensional ordered nitrogen-doped carbon catalysts all have good catalytic activity for TADBIW (Examples 5, 6, 7, 8). Among them, the PdNi / DOM-NC catalyst has the highest activity. However, when the catalyst dosage drops to Pd: TADBIW = 2.5 wt.‰ (Examples 1, 2, 3, 4), the catalytic activities of bimetallic PdFeDOM-NC, PdCu / DOM-NC and single Pd / DOM-NC all show a significant decrease, while the PdNi / DOM-NC catalyst still maintains a relatively high catalytic activity. This shows the strengthening effect of Ni doping on Pd as the active site, enabling this catalyst to provide sufficient active sites even at a lower Pd dosage to convert TADBIW into TAIW, effectively reducing production costs and improving catalytic economy. The commercially available Pd / C and the nitrogen-doped carbon catalyst Pd / NC supported on conventional ZIF-8 as the precursor in Comparative Examples 1 to 4 are mainly microporous structures and have low catalytic activities at different Pd dosages, indicating the superiority of the three-dimensional ordered macroporous structure in the catalytic process of such macromolecules. The orderly interconnected macroporous channels strengthen the mass transfer process and greatly improve the catalytic efficiency.

Claims

1. A preparation method of a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon, characterized in that, It includes the following steps: 1) Synthesize PS microspheres 2) Prepare the macroporous support and load metal M Dissolve Zn(NO3)2·6H2O, 2-methylimidazole and metal M salt in a methanol solution to obtain solution A; the metal M is one of Cu, Fe, Ni, Co or Mn; Place the PS microspheres and solution A in a flask, vacuum degas and then stand still for 1 - 1.2 h, filter and collect product A and dry it. Then place product A in a flask, add a methanol / ammonia water mixed solution, vacuum degas, restore to normal pressure and stand still at room temperature for 24 - 28 h, filter and collect product B and dry it. Then place product B in a tubular furnace, introduce an inert gas, heat it at a rate of 9 - 11 °C / min to 400 - 420 °C, calcine for 3.8 - 4.2 h, and then continue to heat it at a rate of 4.8 - 5.2 °C / min to 950 - 1050 °C and calcine for 1 - 1.1 h, cool to room temperature and take it out to obtain the three-dimensional ordered macroporous nitrogen-doped carbon material M / DOM-NC loaded with metal M; 3) Load metal Pd by impregnation reduction method Mix M / DOM-NC with water and disperse it evenly by ultrasonic wave. Stir at 75 - 85 °C to obtain a support suspension. Adjust the pH of the support suspension to 11 - 12 with an alkali solution. Dissolve the Pd salt in water and then drop it into the support suspension, stir for 8 - 9 h. After the suspension cools, filter, wash and dry it. Place the product in a porcelain boat and put it into a tubular furnace. Pass H2 at a rate of 38 - 42 mL / min, heat it at a rate of 4.8 - 5.2 °C / min to 200 - 220 °C and reduce it at this temperature for 1 - 1.1 h, cool and take it out to obtain the PdM / DOM-NC catalyst.

2. The preparation method of a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon according to claim 1, wherein The method for synthesizing PS microspheres in step 1) is as follows: Wash styrene with a NaOH solution and water. Measure 32.5 mL of the washed styrene and add it to a three-necked flask, and mix it with 250 mL of water and 1.25 g of polyvinylpyrrolidone. Bubble nitrogen for 20 - 25 min. Stir the mixture at 70 - 75 °C under a N2 atmosphere for 30 - 40 min, then add 25 mL of an aqueous solution containing an initiator, and stir at 80 - 88 °C under the protection of a N2 atmosphere at a rotation speed of 500 - 600 rpm for 24 - 28 h to obtain a PS microsphere emulsion suspension. Centrifuge the suspension, collect the precipitate and wash it, and dry it under vacuum to obtain PS microspheres.

3. The preparation method of a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon according to claim 2, characterized in that, The initiator is one of K2S2O8, Na2S2O8, (NH4)2S2O8.

4. The preparation method of a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon according to claim 1, characterized in that, In step 2), the molar ratio of Zn(NO3)2·6H2O to 2-methylimidazole is 1:3, and the metal M salt is one of the sulfate, nitrate, acetate, and chloride salts containing metal M.

5. The preparation method of a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon according to claim 1, wherein, In step 2), the product A is dried at 50 - 60 °C for 7.5 - 8.5 h, the product B is dried at room temperature for 18 - 24 h, the volume ratio of methanol to ammonia water in the methanol / ammonia water mixed solution is 3:4, the inert gas is nitrogen or argon, and the rate of introducing the inert gas is 38 - 42 mL / min.

6. The preparation method of a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon according to claim 1, characterized in that, In step 3), the alkaline solution is one of sodium bicarbonate, sodium hydroxide, and ammonia water.

7. The preparation method of a PdM catalyst supported on three-dimensionally ordered macroporous nitrogen-doped carbon according to claim 1, wherein, In step 3), the Pd salt is one of palladium nitrate, palladium chloride, chloropalladic acid, sodium tetrachloropalladate, and tetraamminepalladium sulfate; the Pd loading of the obtained PdM / DOM-NC catalyst is 1% - 10%.

8. A three-dimensionally ordered macroporous nitrogen-doped carbon-supported PdM catalyst obtained by the preparation method according to any one of claims 1 - 7.

9. Application of a three-dimensionally ordered macroporous nitrogen-doped carbon-supported PdM catalyst as claimed in claim 8 in the hydrocracking of TADBIW.

10. The application according to claim 8, wherein The mass ratio of Pd in the catalyst to the mass of TADBIW is 0.001 - 0.01, the catalytic reaction temperature is between 40 - 60 °C, and the catalytic reaction time is 80 - 300 min.

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