Method for constructing energetic transition metal complexes based on waste biomass cellulose and products and applications thereof

Abstract

The present application provides a kind of method for constructing energetic transition metal complex based on waste biomass cellulose and its product and application. Specifically, 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material is prepared by hydrothermal method, which effectively solves the problems of energy loss, incompatible catalytic performance and chemical compatibility, high preparation cost and other problems caused by the introduction of inert combustion catalyst in the prior art. The composite material prepared by the present application has the advantages of stable morphology, high specific surface area and good nanoparticle dispersity. As a combustion catalyst, it can not only catalyze the thermal decomposition of ammonium perchlorate (significantly reduce the thermal decomposition temperature of ammonium perchlorate, increase the total heat release and the activation energy of ammonium perchlorate at low temperature decomposition stage); but also improve the stability and reliability of doped ammonium perchlorate. In addition, the process of the present application is simple, the reaction conditions are mild, the amount of organic reagent is small, the raw materials are widely available and the cost is low, which is especially suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of combustion catalyst technology, specifically relating to a method for constructing energetic transition metal complexes based on waste biomass cellulose and the products thereof. Background Technology

[0002] Ammonium perchlorate is a commonly used oxidizer component in modern composite solid propellants. Its thermal decomposition characteristics (such as decomposition rate and exothermic behavior) are among the main factors determining the combustion rate, energy release efficiency, and specific impulse of solid propellants. However, ammonium perchlorate itself has inherent defects such as excessively high decomposition temperature, incomplete combustion, and non-concentrated exothermic behavior, which severely reduce the combustion performance of propellants. Combustion catalysts are currently the most effective strategy for controlling the decomposition characteristics of ammonium perchlorate.

[0003] However, existing combustion catalyst systems generally suffer from the following key problems: ① Commonly used inert combustion catalysts themselves contain no energy, and the introduction of ammonium perchlorate leads to a decrease in the overall energy of the system; ② Although nano-sized combustion catalysts can effectively improve catalytic performance, the high surface energy of the catalyst and the strong van der Waals forces between nanoparticles make them prone to aggregation, reducing dispersibility and the number of active sites, resulting in a significant decline in catalytic performance; ③ The catalytic activity and chemical compatibility with ammonium perchlorate are not uniform. Furthermore, long-term storage of a mixture of combustion catalyst and ammonium perchlorate will slowly generate gas, leading to problems such as propellant aging and cracking, and a decrease in stability and performance. The higher the catalytic activity of existing catalysts, the worse their chemical compatibility with ammonium perchlorate tends to be.

[0004] In summary, providing a novel catalyst that combines high energy sensitivity, good catalytic performance, high stability, and economic feasibility is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a method for preparing 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material using a hydrothermal method, which effectively solves the problems of energy loss, incompatibility of catalytic performance and chemical compatibility, and high preparation cost caused by the introduction of inert combustion catalysts in the prior art.

[0006] To achieve the above objectives, the present invention provides a method for constructing energetic transition metal complexes based on waste biomass cellulose, characterized in that...

[0007] (I) Modification treatment of waste cellulose: Waste biomass cellulose raw materials are crushed and sieved, and alkaline reagents are added. Alkaline treatment is carried out under the first temperature condition. The resulting product is mixed with biological enzymes and fermented under the second temperature condition for a period of time. The resulting product is dispersed in a weak acid-weak acid salt buffer system. 2,2,6,6-Tetramethylpiperidine oxide, sodium chlorite and sodium hypochlorite are added in sequence. After stirring and reacting under the third temperature condition for a period of time, the resulting product is washed and dried to obtain modified cellulose.

[0008] (II) Preparation of 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material:

[0009] (1) Weigh 0.005-0.1g of the obtained modified cellulose, 0.1-1.5mmol of transition metal nitrate and 4-50mL of mixed solvent, mix them evenly, heat them at the fourth temperature condition for a period of time, and then cool them naturally.

[0010] (2) Add 4-nitro-1H-indazole-6-carboxylic acid to the cooled solution. The molar ratio of 4-nitro-1H-indazole-6-carboxylic acid to the transition metal ion is 1:(0.1~10). Heat the mixture at the fifth temperature condition for a period of time. After natural cooling, wash and dry to obtain the 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material.

[0011] In a preferred embodiment, in the step of modifying waste cellulose (I), the waste biomass cellulose raw material includes Bupleurum chinense residue; preferably, the Bupleurum chinense residue is the residue after water extraction and alcohol precipitation, which can be obtained by conventional methods known to those skilled in the art, such as: after pulverizing Bupleurum chinense, adding distilled water at a material-to-liquid ratio of 1g:(15-20)mL, soaking for 15-30 minutes, and then heating and refluxing at 95-105℃ for 1-3 times, each time for 1-2 hours, and combining the filtrates; concentrating the filtrate to 1 / 5-1 / 10 of the original volume at 60-70℃ and a vacuum degree of -0.06 to -0.08MPa, cooling, and slowly adding 95% ethanol to make the final ethanol concentration reach 70-80%, stirring evenly, sealing, and standing at 4℃ for 12-24 hours; centrifuging at 4000-5000rpm for 10-15 minutes, collecting the precipitate, washing, and drying to obtain the Bupleurum chinense residue after extraction.

[0012] Natural cellulose has a large number of hydroxyl groups on its surface, which are converted into carboxyl groups through oxidation, allowing for the anchoring of energetic complex particles using chemical bonds. After simple alkali treatment and fermentation to remove lignin and hemicellulose, the biomass waste, such as Bupleurum chinense residue, possesses excellent properties of high porosity and high specific surface area, making it an ideal loading material. Furthermore, the Bupleurum chinense residue has already undergone organic solvent extraction, saving on cellulose processing steps. Compared to traditional carbon nanomaterials (carbon nanotubes, graphene, etc.), natural cellulose has advantages such as low cost, no pollution, mild chemical modification, and wide availability. Therefore, this invention selects waste Bupleurum chinense residue as the cellulose raw material.

[0013] In a preferred embodiment, in the (a) waste cellulose modification treatment step, the sieve mesh size is 50 to 300 mesh.

[0014] Waste biomass cellulose raw materials are crushed and sieved to obtain micro-nano-sized powders. This process can not only destroy the aggregated structure of cellulose and fully expose hemicellulose and lignin, which is beneficial for subsequent alkali treatment and fermentation to remove hemicellulose and lignin, but also control the particle size distribution by sieving, increase the specific surface area, and increase the loading of energetic complex particles.

[0015] In a preferred embodiment, in the step of modifying waste cellulose (a), the alkaline reagent includes a sodium hydroxide solution; preferably, the concentration of the sodium hydroxide solution is 0.05 to 0.5 mol / L.

[0016] In a preferred embodiment, in the step of modifying waste cellulose, the mass-to-volume ratio of the waste biomass cellulose to the alkaline reagent is (0.05-100) g: 1000 mL.

[0017] In a preferred embodiment, in the (a) waste cellulose modification treatment step, the first temperature condition includes 100-250°C, and the alkali treatment time is 2-10 hours.

[0018] In this step, alkaline reagents (such as NaOH and KOH) can dissolve impurities such as lignin and hemicellulose, while breaking the hydrogen bonds between cellulose molecules, creating conditions for the introduction of functional groups, thereby enhancing their coordination ability with transition metal ions.

[0019] In a preferred embodiment, in the (i) waste cellulose modification step, the bioenzyme includes cellulase and / or xylanase; preferably, the bioenzyme is a mixture of cellulase and xylanase in a mass ratio of (0.1-2):1.

[0020] In a preferred embodiment, in the step of modifying waste cellulose (a), the mass ratio of the product after alkali treatment to the bioenzyme is (0.01-4):1.

[0021] In a preferred embodiment, in the (a) waste cellulose modification treatment step, the second temperature condition includes 45-70°C, and the fermentation time is 10-60 h.

[0022] In this step, enzymatic fermentation using cellulase and / or xylanase selectively decomposes cellulose and hemicellulose, preserving the cellulose skeleton as a catalyst carrier while removing impurities through synergistic alkali treatment and enzymatic hydrolysis.

[0023] In a preferred embodiment, in the modification treatment step of waste cellulose (I), after the fermentation is completed, the process further includes inactivation, washing and drying. The inactivation can be carried out using conventional methods known to those skilled in the art, such as inactivation treatment at 80-100°C for 2-3 hours. The washing includes washing with deionized water 2-4 times, followed by rinsing with anhydrous ethanol 1-2 times. The drying includes drying at 50-60°C for 2-6 hours.

[0024] In a preferred embodiment, in the (a) waste cellulose modification step, the weak acid-weak salt buffer system includes an acetate-sodium acetate buffer solution; preferably, the pH of the weak acid-weak salt buffer system is 1 to 7.

[0025] In a preferred embodiment, in the (a) waste cellulose modification treatment step, the mass-to-volume ratio of the fermentation product to the weak acid-weak salt buffer system is (0.1-100) g:1 L.

[0026] In this step, the main function of the acetate-sodium acetate buffer solution is to ensure that the pH of the reaction system remains constant during the reaction process, so as not to affect the biological activity of the complex enzyme; secondly, it serves to disperse cellulose and the complex enzyme. The mass-to-volume ratio of the fermented cellulose to the buffer solution has a significant impact on the fermentation efficiency; if it exceeds this range, the efficiency of removing hemicellulose and lignin from the cellulose decreases sharply.

[0027] In a preferred embodiment, in the (i) waste cellulose modification step, the mass ratio of the fermentation product, 2,2,6,6-tetramethylpiperidine oxide (TEMPO), sodium chlorite, and sodium hypochlorite is (0.1–50):(0.01–10):(0.01–30):(0.01–30).

[0028] In this step, TEMPO, sodium chlorite, and sodium hypochlorite are used synergistically as a modifier, which oxidizes the C6-OH of cellulose to generate carboxylate anions (-COO-). -The formulation design and mixing ratio of the modifiers (TEMPO, sodium chlorite, and sodium hypochlorite), as well as the ratio of the modifiers to the fermentation products, all determine the conversion rate of hydroxyl groups on the cellulose surface. Exceeding the aforementioned range will significantly reduce the hydroxyl oxidation efficiency, thereby affecting the content of carboxyl groups generated.

[0029] In a preferred embodiment, in the (a) waste cellulose modification treatment step, the third temperature condition includes 45-70°C, and the stirring reaction time is 10-60 h.

[0030] In a preferred embodiment, in the (a) waste cellulose modification treatment step, the washing and drying can be carried out using conventional methods known to those skilled in the art, such as washing including washing with deionized water 2 to 4 times, and then rinsing with anhydrous ethanol 1 to 2 times; drying including drying at 50 to 60°C for 2 to 6 hours.

[0031] In a preferred embodiment, in step (1) of (ii) preparing the composite material, the transition metal nitrate includes Co(NO3)2·6H2O and / or Fe(NO3)3·6H2O.

[0032] In a preferred embodiment, in step (1) of preparing the composite material (ii), the mixed solvent comprises N,N-dimethylformamide (DMF) / H2O and / or N,N-dimethylformamide (DMF) / ethanol; preferably, the mixed solvent is composed of DMF and H2O in a volume ratio of (0.1-3):1; preferably, the mixed solvent is composed of DMF and ethanol in a volume ratio of (0.1-3):1.

[0033] This invention, through extensive experimental research, has discovered that mixed solvents significantly affect the morphology and aggregation state of energetic complexes in composite materials. For different metal types, selecting N,N-dimethylformamide (DMF) / H₂O and / or N,N-dimethylformamide (DMF) / ethanol can yield composite materials with controllable morphology. Simultaneously, excessive or insufficient volume of the mixed solvent leads to insufficient loading of energetic complex particles on the cellulose surface or severe aggregation. Therefore, this invention designs the aforementioned dosage ratios.

[0034] In a preferred embodiment, in step (1) of preparing the composite material (ii), in order to improve the mixing effect of modified cellulose, transition metal nitrate and mixed solvent, ultrasonic dispersion at 100-900W for 5-20 minutes can be used.

[0035] In a preferred embodiment, in step (1) of preparing the composite material (ii), the fourth temperature condition includes 100-150°C and the heating time is 3-12 h.

[0036] In a preferred embodiment, in step (2) of preparing the composite material, 4-nitro-1H-indazole-6-carboxylic acid, CAS No. 885519-71-1.

[0037] In a preferred embodiment, in step (2) of preparing the composite material, in order to improve the dispersion effect of 4-nitro-1H-indazole-6-carboxylic acid in the system, ultrasonic dispersion at 100-900W can be used for 5-20 minutes.

[0038] In a preferred embodiment, in step (2) of preparing the composite material, the fifth temperature condition includes 100-150°C and the heating time is 3-12 h.

[0039] In this invention patent, the preparation of the composite material is carried out in two steps. First, under a fourth temperature condition, the carboxyl groups on the surface of modified cellulose coordinate with metal ions. This temperature should not be set too high to avoid chemical reactions with the solvent. Subsequently, energetic organic molecules are introduced, and under a fifth temperature condition, the energetic organic molecules coordinate with the metal ions and attach to the cellulose surface. The reaction time is 3–12 hours to ensure that the cellulose surface complex nucleates and grows into nano-sized particles. Temperatures above 150°C are prone to decomposition, and temperatures below 100°C result in uncontrollable morphology of the complex. Both reaction steps take 3–12 hours to ensure sufficient reaction in each step and uniform particle size of the cellulose surface complex.

[0040] In a preferred embodiment, in step (2) of preparing the composite material, the washing and drying can be carried out using conventional methods known to those skilled in the art, such as washing with deionized water 2 to 4 times; and drying at 50 to 60°C for 2 to 6 hours.

[0041] Another object of the present invention is to provide a 2,4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material prepared by any of the above methods.

[0042] In a preferred embodiment, the particle size of the composite material is 50 nm to 500 μm, and according to NH3-TPD testing (heating range 50 to 300 °C), the number of acidic sites on the surface of the composite material is 1 to 2.5 mmol / g.

[0043] Another object of the present invention is to provide the application of the 2,4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material prepared by any of the above methods in the catalytic thermal decomposition of ammonium perchlorate.

[0044] In a preferred embodiment, the catalytic thermal decomposition of ammonium perchlorate includes one or more of the following: reconstructing the thermal decomposition pathway, lowering the high-temperature decomposition energy barrier, increasing the low-temperature decomposition rate, and enhancing energy release.

[0045] In a preferred embodiment, the amount of the 2,4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material is 1 to 3 wt%, that is, the weight of the composite material accounts for 1 to 3% of the total weight of the composite material and ammonium perchlorate.

[0046] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0047] (1) From the perspective of material properties, the 4-nitro-1H-indazole-6-carboxylic acid nitrogen-rich heterocyclic transition metal complex / modified cellulose composite material prepared in this invention has the advantages of high density, high heat of formation and low toxicity of combustion products. This composite material can not only efficiently catalyze the thermal decomposition of ammonium perchlorate, but also compensate for the energy loss of the system caused by the addition of an inert combustion catalyst.

[0048] (2) From a structural design perspective, in the construction of composite materials, metal ions act as central nodes, and through coordination with carboxyl groups and nitrogen-rich heterocyclic ligands on the surface of cellulose, they self-assemble into energetic complex nanoparticles on the surface of natural cellulose. This structural design avoids the aggregation of nanoparticles and improves the long-term storage stability of the material. In addition, natural cellulose can achieve uniform dispersion of nanoparticles through the anchoring effect of surface carboxyl groups, thereby stabilizing the energetic complex and reducing its mechanical sensitivity.

[0049] To address the problem of balancing catalytic activity and chemical compatibility in traditional combustion catalysts, the natural cellulose support selected in this invention, due to its loading of energetic complexes, not only significantly improves the decomposition rate of ammonium perchlorate but also reduces the activation energy in the low-temperature decomposition stage, exhibiting excellent catalytic activity; at the same time, the material system also shows good chemical compatibility.

[0050] (3) From the perspective of preparation process, the novel catalyst provided by this invention is prepared by hydrothermal method, which has the advantages of simple process, mild reaction conditions and small amount of organic reagents. Moreover, the cellulose raw material used is waste biomass cellulose (such as Bupleurum chinense residue), which is widely available and inexpensive, and is especially suitable for large-scale industrial production. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0052] Figure 1 The images shown are SEM images and physical images of the products obtained in Examples 1 and 3 of the present invention; wherein, (a) is a physical image of the product of Example 1, (b) is a physical image of the product of Example 3, (c) is a SEM image of the product of Example 1, and (d) is a SEM image of the product of Example 3.

[0053] Figure 2 The microstructure characterization diagrams of the product obtained in Example 1 of the present invention are shown; wherein, (a) is a TEM image, (b) is an HRTEM image, and (cg) is an EDX-mapped elemental analysis diagram.

[0054] Figure 3 The microstructure characterization diagrams of the product obtained in Example 3 of the present invention are shown; wherein, (a) is a TEM image, (b) is an HRTEM image, and (cg) is an EDX mapping elemental analysis diagram;

[0055] Figure 4 The images show SEM images of Examples 1 and 2 of the present invention, the test results of the thermal decomposition of pure ammonium perchlorate, and the kinetic linear fitting graphs. Among them, (a) is the SEM image of Example 1, (b) is the SEM image of Example 2, (c) is the DSC curve of 2% Example 1 + 98% ammonium perchlorate at different heating rates, (d) is the DSC curve of 2% Example 2 + 98% ammonium perchlorate at different heating rates, and (e) is the linear fitting result of the thermal decomposition kinetics of 2% Example 1 + 98% ammonium perchlorate and 2% Example 2 + 98% ammonium perchlorate.

[0056] Figure 5The images shown are SEM images of Examples 3, 4, 5, and 6 of this invention, along with test results of the thermal decomposition of pure ammonium perchlorate and kinetic linear fitting graphs. Specifically, (a) is the SEM image of Example 3, (b) is the SEM image of Example 4, (c) is the SEM image of Example 5, (d) is the SEM image of Example 6, (e) is the DSC curve of 2% Example 3 + 98% ammonium perchlorate at different heating rates, (f) is the DSC curve of 2% Example 4 + 98% ammonium perchlorate at different heating rates, (g) is the DSC curve of 2% Example 5 + 98% ammonium perchlorate at different heating rates, (h) is the DSC curve of 2% Example 6 + 98% ammonium perchlorate at different heating rates, and (I) shows the linear fitting results of the thermal decomposition kinetics of 2% Example 3 + 98% ammonium perchlorate, 2% Example 4 + 98% ammonium perchlorate, 2% Example 5 + 98% ammonium perchlorate, and 2% Example 6 + 98% ammonium perchlorate.

[0057] Figure 6 The figures show the thermal decomposition test results of pure ammonium perchlorate (AP). In the figure, (a) is the DSC curve of pure ammonium perchlorate at different heating rates, and (b) is the linear fitting result of the thermal decomposition kinetics of pure ammonium perchlorate. Detailed Implementation

[0058] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] The technical solution of this application will be described in detail below through specific embodiments:

[0060] Unless otherwise specified, the technical means used in this invention are conventional means well known to those skilled in the art. All raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. Unless otherwise specified, all reagents used in this invention are of analytical grade. The Bupleurum chinense residue used in this embodiment of the invention was prepared by the following method: Bupleurum chinense was pulverized, and distilled water was added at a material-to-liquid ratio of 1g:15mL. After soaking for 15 minutes, the mixture was extracted three times by reflux at 100℃, each time for 1 hour, and the filtrates were combined. The filtrate was concentrated to 1 / 5 of its original volume at 60℃ and a vacuum of -0.06 to -0.08MPa. After cooling, 95% ethanol was slowly added to achieve a final ethanol concentration of 70%. After stirring evenly, the mixture was sealed and allowed to stand at 4℃ for 12 hours. The precipitate was collected by centrifugation at 4000rpm for 10 minutes, washed, and dried to obtain the Bupleurum chinense residue. The 4-nitro-1H-indazole-6-carboxylic acid used in this embodiment of the invention was purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.

[0061] In this invention, the weight parts can be weight units known in the art such as μg, mg, g, kg, or multiples thereof, such as 1 / 10, 1 / 100, 10 times, 100 times, etc.

[0062] Example 1 Preparation of [4-NI6A]Co / NC (0.30 / 0.15-DMF + ethanol-100 / 100)

[0063] Modification treatment of waste cellulose:

[0064] (1) Crush the Bupleurum chinense residue and pass it through a 200-mesh sieve. Take the cellulose powder that passes through the 200-mesh sieve and treat it with sodium hydroxide solution at 160℃ for 4 hours (the mixing ratio of cellulose powder and 0.1mol / L sodium hydroxide solution is 50g:1000mL) to obtain product 1.

[0065] (2) The obtained product 1 was mixed with a complex bio-enzyme (cellulase and xylanase) at a mass ratio of 4:6, wherein the mass ratio of cellulase to xylanase in the complex bio-enzyme was 1:1. The mixture was fermented at 55℃ for 48 hours. After fermentation, the mixture was inactivated at 90℃ for 3 hours, centrifuged, washed three times with water, rinsed once with anhydrous ethanol, and dried at 60℃ for 4 hours to obtain product 2.

[0066] (3) Weigh 1g of product 2 and disperse it in 80mL of acetate-sodium acetate buffer solution (pH=4.5). Add TEMPO (0.16g), sodium chlorite (1.81g), and sodium hypochlorite (1.41g) in sequence. Stir continuously at 60℃ for 48h. After the reaction is complete, centrifuge to separate the product. Wash the product three times with water and once with anhydrous ethanol. Dry at 60℃ for 4 hours to obtain product 3.

[0067] Preparation of cobalt 4-nitro-1H-indazole-6-carboxylate complex / modified cellulose:

[0068] (4) In the first stage, metal ions are loaded onto the surface of cellulose: 0.01 g of product 3 and 0.30 mmol of Co(NO3)2·6H2O are weighed and added to the lining of the hydrothermal reactor. Then, 16 mL of mixed solvent (DMF and ethanol are mixed in a volume ratio of 1:1) is added to the lining. The solution is sonicated for 10 min to make it uniform. Then, it is heated at 100℃ for 6 h and allowed to cool naturally.

[0069] (5) Second stage, ligands are coordinated with metal ions and loaded onto the cellulose surface: 0.15 mmol of 4-nitro-1H-indazole-6-carboxylic acid is added to the cooled solution, sonicated for 10 min, heated at 100℃ for 10 h, and after natural cooling, filtered, the filter cake is washed twice with water, and dried at 60℃ for 2 h to obtain the product 4-nitro-1H-indazole-6-carboxylic acid cobalt / modified cellulose composite material.

[0070] Figure 1 The images show (a) and (c) scanning electron micrographs of the [4-NI6A]Co / NC composite material prepared in Example 1. It can be observed that the resulting composite material is yellow and powdery, and the [4-NI6A]Co / NC prepared by the hydrothermal method exhibits a nanoflower-like morphology. Figure 2 The TEM and HRTEM images show that the complex is composed of many layers of sheet-like material stacked together, with a clear layered structure; the nanoparticles are well dispersed and do not exhibit agglomeration.

[0071] Example 2: Preparation of [4-NI6A]Co / NC(0.24 / 0.12-DMF+ethanol-100 / 100)

[0072] The only difference between this embodiment and Example 1 is that in step (4), the amount of Co(NO3)2·6H2O used is 0.24 mmol, and in step (5), the amount of 4-nitro-1H-indazole-6-carboxylic acid used is 0.12 mmol. The other raw materials and steps are exactly the same as in Example 1.

[0073] Example 3: Preparation of [4-NI6A]Fe / NC(0.24 / 0.12-DMF+water-100 / 100)

[0074] The modification treatment of waste cellulose is the same as in Example 1.

[0075] Preparation of ferric complex of 4-nitro-1H-indazole-6-carboxylic acid / modified cellulose:

[0076] (4) In the first stage, metal ions are loaded onto the surface of cellulose: 0.01 g of product 3 and 0.24 mmol of Fe(NO3)3·6H2O are weighed and added to the lining of the hydrothermal reactor. Then, 8 mL of mixed solvent (DMF and H2O mixed in a volume ratio of 1:1) is added to the lining. The solution is sonicated for 10 min to make it uniform. Then, it is heated at 100℃ for 6 h and allowed to cool naturally.

[0077] (5) In the second stage, the ligands are coordinated with metal ions and loaded onto the cellulose surface: 0.12 mmol of 4-nitro-1H-indazole-6-carboxylic acid is added to the cooled solution, sonicated for 10 min, heated at 100℃ for 10 h, and after natural cooling, filtered. The filter cake is washed twice with water and dried at 60℃ for 2 h to obtain the product 4-nitro-1H-indazole-6-carboxylic acid iron / modified cellulose composite material.

[0078] Figure 1 Image (b) and scanning electron micrograph (d) of the [4-NI6A]Fe / NC composite material prepared in Example 3. The resulting composite material is observed to be reddish-brown and powdery. Furthermore, the [4-NI6A]Fe / NC prepared via hydrothermal method exhibits a microstructure of uniformly distributed nanoparticles on the cellulose surface. Figure 3 TEM and HRTEM images show that the complex consists of near-spherical nanoparticles. The particle size is approximately 15-50 nm, and no obvious aggregation is observed.

[0079] Example 4: Preparation of [4-NI6A]Fe / NC(0.24 / 0.12-DMF+water-100 / 120)

[0080] The only difference between this embodiment and Example 3 is that in step (5), the heating temperature of the second stage reaction is 120°C. The other raw materials and steps are exactly the same as in Example 3.

[0081] Example 5: Preparation of [4-NI6A]Fe / NC(0.19 / 0.09-DMF+water-100 / 120)

[0082] The only difference between this embodiment and Example 4 is that in step (4), the Fe(NO3)3·6H2O used is 0.19 mmol, and in step (5), the 4-nitro-1H-indazole-6-carboxylic acid used is 0.09 mmol. The other raw materials and steps are exactly the same as in Example 4.

[0083] Example 6: Preparation of [4-NI6A]Fe / NC(0.24 / 0.12-DMF+water-120 / 120)

[0084] The only difference between this embodiment and Example 4 is that in step (4), the heating temperature of the first stage reaction is 120°C. The other raw materials and steps are exactly the same as in Example 4.

[0085] Application Example 1: Thermal Decomposition of Ammonium Perchlorate

[0086] Take 3 mg of ammonium perchlorate for DCS testing. Test conditions: heating rate 5, 10, 15, 20℃ / min, heating range 100-500℃, nitrogen atmosphere, flow rate 20 mL / min.

[0087] Application Example 2: Thermal Decomposition Analysis of Ammonium Perchlorate Catalyzed by [4-NI6A]Co / NC

[0088] 2 mg of the [4-NI6A]Co / NC composite material prepared in Examples 1-2 was added to an agate mortar and mixed and ground with 98 mg of ammonium perchlorate. After thorough grinding, 3 mg of the sample to be tested was weighed. The test conditions were the same as in Application Example 1.

[0089] Application Example 3: Thermal Decomposition Analysis of Ammonium Perchlorate Catalyzed by [4-NI6A] Fe / NC

[0090] 2 mg of the [4-NI6A]Fe / NC composite material prepared in Examples 3-6 was added to an agate mortar and mixed and ground with 98 mg of ammonium perchlorate. After thorough grinding, 3 mg of the sample to be tested was weighed. The test conditions were the same as in Application Example 1.

[0091] The test results for Application Example 1-3 are shown in Table 1:

[0092] Table 1

[0093]

[0094] Results and Discussion:

[0095] (1) The thermal decomposition test results of pure ammonium perchlorate are shown in the figure. Figure 6 The high-temperature decomposition temperature of pure ammonium perchlorate is 416℃, with a total heat release of 613 J / g. Its activation energy Ea in the low-temperature decomposition stage is 127 kJ / mol, and its rate constant k is 0.46 min⁻¹. -1 The activation energy Ea of the high-temperature decomposition stage is 324 kJ / mol, and the rate constant k is 0.77 min. -1 .

[0096] (2) The [4-NI6A]Co / NC prepared in Examples 1 and 2 have a significant catalytic effect on the thermal decomposition of ammonium perchlorate, which advances the thermal decomposition of ammonium perchlorate. Figure 4(c) The DSC curves show that the [4-NI6A]Co / NC composite material prepared in Example 1 has the best catalytic effect on ammonium perchlorate. The [4-NI6A]Co / NC prepared in Example 1 advances the high-temperature decomposition peak temperature of ammonium perchlorate to 332℃ and increases the heat release to 1108 J / g. The kinetic parameters of the thermal decomposition of the [98% Example 1 + 98% ammonium perchlorate] mixture were calculated using the Kissinger equation method. The activation energy Ea in the low-temperature decomposition stage increased from 127 kJ / mol (pure ammonium perchlorate) to 258 kJ / mol, indicating that ammonium perchlorate and [4-NI6A]Co / NC have good chemical compatibility. The rate constant k increased from 0.46 min... -1 (Ammonium perchlorate) increased to 0.91 min -1 It exhibits excellent catalytic performance; the activation energy Ea in the high-temperature decomposition stage is reduced from 324 KJ / mol (ammonium perchlorate) to 228 KJ / mol, while the rate constant k remains largely unaffected, eliminating the stagnation period between low-temperature and high-temperature decomposition and resulting in more concentrated heat release.

[0097] (3) According to the results of the [4-NI6A]Fe / NC catalyzed thermal decomposition of ammonium perchlorate prepared in Examples 3-6, it can be seen that all products have obvious catalytic effects on the thermal decomposition of ammonium perchlorate, which advances the thermal decomposition of ammonium perchlorate. Figure 5 The DSC curves in (e) show that the [4-NI6A]Fe / NC composite material prepared in Example 3 exhibits the best catalytic effect on ammonium perchlorate. The addition of this catalyst merges the low-temperature decomposition peak and the high-temperature decomposition peak of ammonium perchlorate into a single exothermic peak. The decomposition temperature is 361°C, and the total exothermic heat is 1684 J / g. The kinetic parameters of the thermal decomposition of [98% Example 3 + 98% ammonium perchlorate] were calculated using the Kissinger equation method. The activation energy Ea of the low-temperature decomposition stage increased from 127 kJ / mol (ammonium perchlorate) to 150 kJ / mol, and the rate constant k increased from 0.46 min⁻¹. -1 (Ammonium perchlorate) increased to 0.63 min -1 This indicates that ammonium perchlorate has good chemical compatibility with [4-NI6A]Fe / NC and exhibits excellent catalytic performance, eliminating the stagnation period between low-temperature and high-temperature decomposition and resulting in more concentrated exothermic reactions.

[0098] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for preparing 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite materials using a hydrothermal method, characterized in that, (a) Modification treatment of waste cellulose: Waste biomass cellulose raw materials are crushed and sieved, and alkaline reagents are added. Alkaline treatment is carried out under the first temperature condition. The resulting product is mixed with biological enzymes and fermented under the second temperature condition for a period of time. The resulting product is dispersed in a weak acid-weak acid salt buffer system. 2,2,6,6-Tetramethylpiperidine oxide, sodium chlorite and sodium hypochlorite are added in sequence. After stirring and reacting under the third temperature condition for a period of time, the resulting product is washed and dried to obtain modified cellulose. (II) Preparation of 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material: (1) Weigh 0.005~0.1g of the obtained modified cellulose, 0.1~1.5mmol of transition metal nitrate and 4~50mL of mixed solvent, mix them evenly, heat them at the fourth temperature condition for a period of time, and then cool them naturally. (2) Add 4-nitro-1H-indazole-6-carboxylic acid to the cooled solution. The molar ratio of 4-nitro-1H-indazole-6-carboxylic acid to the transition metal ion is 1:(0.1~10). Heat the mixture at the fifth temperature condition for a period of time. After natural cooling, wash and dry to obtain the 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material. In step (1) of preparing the composite material in (ii), the transition metal nitrate is Co(NO3)2·6H2O or Fe(NO3)3·6H2O; the mixed solvent is N,N-dimethylformamide / H2O or N,N-dimethylformamide / ethanol; In step (2) of preparing the composite material, the heating temperature of the fifth temperature condition is 100~150 ℃ and the heating time is 3~12 h.

2. The method for preparing 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material by hydrothermal method as described in claim 1, characterized in that, In the modification treatment step of (i) waste cellulose, the waste biomass cellulose raw material includes Bupleurum chinense residue; the alkaline reagent includes sodium hydroxide solution; the mass-volume ratio of the waste biomass cellulose to the alkaline reagent is (0.05~100) g:1000 mL.

3. The method for preparing 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material by hydrothermal method as described in claim 1, characterized in that, In the modification treatment step of waste cellulose (I), the bio-enzyme includes cellulase and / or xylanase; the mass ratio of the product after alkali treatment to the bio-enzyme is (0.01~4):

1.

4. The method for preparing 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material by hydrothermal method as described in claim 1, characterized in that, In the modification treatment step of waste cellulose (I), the weak acid-weak acid salt buffer system includes an acetate-sodium acetate buffer solution; the mass-volume ratio of the fermentation product to the weak acid-weak acid salt buffer system is (0.1~100) g:1 L.

5. The method for preparing 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material by hydrothermal method as described in claim 1, characterized in that, In the modification treatment step of waste cellulose (I), the mass ratio of fermentation product, 2,2,6,6-tetramethylpiperidine oxide, sodium chlorite and sodium hypochlorite is (0.1~50):(0.01~10):(0.01~30):(0.01~30).

6. The 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material prepared by the method according to any one of claims 1-5.

7. The application of the 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material prepared by the method according to any one of claims 1-5 in the catalytic thermal decomposition of ammonium perchlorate.

8. The application as described in claim 7, characterized in that, The amount of the 4-nitro-1H-indazole-6-carboxylic acid transition metal complex / modified cellulose composite material is 1~3 wt%.

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