Transition metal doped rare earth ferrocyanide derived multimetal complex nitrogen heterocarbon burning rate catalyst

Abstract

The application discloses a transition metal doped rare earth ferrocyanide derivative multi-metal composite nitrogen heterocarbon burning rate catalyst, wherein the burning rate catalyst is prepared by adding a mixed water solution of soluble salts of transition metals and soluble salts of rare earth metals drop by drop into a saturated aqueous solution of Na4[Fe(CN)6], and then performing solid-liquid separation, washing, drying, and calcining the obtained powder under inert gas protection. The transition metal and the rare earth metal particles are uniformly loaded on the nitrogen heterocarbon material through thermal condensation, the preparation steps are simple, the cost is low, and the obtained composite material can greatly improve the performance as the burning rate catalyst through the synergistic catalytic effect of the multi-metals.

Description

Technical Field

[0001] This invention belongs to the field of solid propellant technology, specifically relating to a multi-metal composite nitrogen-carbon combustion rate catalyst derived from transition metal-doped rare earth ferrocyanate. Background Technology

[0002] With the development of aerospace technology, solid propellants have received increasing attention from researchers. As a crucial functional component of rocket propulsion systems, solid propellants serve as the power source for solid engines in both military and civilian rockets. Their components undergo combustion reactions within the engine through propellant loading design, primarily consisting of oxidizers and reductants. This combustion can be ignited in the oxygen-free environment of space, providing high-temperature gases to power the rocket. Solid propellants can be classified into two types based on their composition: double-base propellants and composite propellants. Future research on solid propellants will focus on developing high-energy, low-signature, insensitive, and economical products. To enhance my country's solid propellant technology production level, research on solid propellants needs to be prioritized. However, solid propellants need to address their drawbacks of low burning rate and high pressure index during use. Therefore, burning rate catalysts need to be added to the propellant loading formulation to improve combustion performance.

[0003] Burning rate catalysts are often classified into burning rate catalysts and burning rate inhibitors based on their effect on propellant combustion rate. To improve the combustion performance and increase the combustion rate of solid propellants, burning rate catalysts are frequently added. As a crucial component of solid propellants, they typically function through chemical reactions to improve combustion performance and meet the launch requirements of different engines and propellants, thus satisfying the needs of modern spacecraft. While there are many types of burning rate modifiers currently available, they can be broadly categorized based on their composition as follows: metals and metal oxides, organometallic compounds, nano-metal powders, carbon materials, and energetic compounds. In recent years, with the continuous deepening of research, rare earth metals have gradually come into the researchers' field of vision as catalysts. Rare earth metals are a collective term for 17 metals, including lanthanides, scandium, and yttrium. In order to improve the thermal characteristics of propellants and reduce the pressure index, many researchers have tried various metal combinations to conduct experiments. Rare earth compounds have a prominent role in the combustion catalysis of double-base propellants and in reducing the infrared decay of fuel gas. In other fields, the composite system of rare earths and other transition elements also has excellent catalytic performance.

[0004] Prussian blue and its analogues, as cyanide-bridged coordination polymers, possess a tunable three-dimensional framework and relatively more active sites, thus exhibiting good catalytic performance. Prussian blue compounds have multi-metal composite properties and good catalytic performance, and also have positive heat of formation, making them suitable as catalysts commonly used in solid propellants. To date, various compounds have been prepared using transition metals, known as Prussian blue analogues. According to Xinhe Bao's research, these compounds can be carbonized in situ at high temperatures to form metal-coated carbon materials. He prepared pod-like nitrogen-doped carbon materials encapsulating FeNi alloy nanoparticles using a direct pyrolysis method with metal-organic precursors, and applied them to the redox reaction of dye-sensitized solar cells, demonstrating excellent electrocatalytic activity (Xi nhe Bao, and Can Li et al. Podlike N-Doped Carbon Nanotubes Encapsulating Fe Ni Alloy Nanoparticles: High-Performance Counter Electrode Materials for Dye-Sensitized Solar Cells. Angewandte. Chemie. 2014(53):7023-7027). Chi Huang et al. prepared a Prussian blue nanosheet assembly material and studied a new pathway for high-efficiency catalysis through its continuous interaction with ammonium perchlorate. The results showed that the decomposition of ammonium perchlorate under the catalysis of this Prussian blue nanosheet exhibited two consecutive exothermic stages, and it was found that this material could maintain excellent catalytic stability (Chi Huang, Peng Zhou et al. Interaction Between Prussian Blue Ultrathin Nanosheet and Ammonium Perchlorate for Highly Efficient Thermal Decomposition. Advanced Functional Materials. 2023(33):2300661-2300672). Summary of the Invention

[0005] The purpose of this invention is to provide a fast, convenient, and readily synthesizable transition metal-doped rare earth ferrocyanate-derived multimetal composite nitrogen-carbon combustion rate catalyst with good catalytic performance.

[0006] The multi-metal composite nitrogen-carbon combustion rate catalyst provided by the present invention is a multi-metal composite nitrogen-carbon material obtained by calcining a Prussian blue analogue of a rare earth metal doped with a transition metal; the transition metal is any one of copper, cobalt, iron, and manganese; the rare earth metal is any one of terbium, samarium, europium, and dysprosium.

[0007] Furthermore, cobalt is preferred among the aforementioned transition metals, and terbium is preferred among the rare earth metals.

[0008] The particle size of the above-mentioned multi-metal composite nitrogen-carbon combustion rate catalyst is 300-500 nm.

[0009] The preparation method of the multi-metal composite nitrogen-carbon combustion rate catalyst of the present invention is as follows: a mixed aqueous solution of soluble salts of transition metals and soluble salts of rare earth metals is added dropwise to a saturated aqueous solution of Na4[Fe(CN)6]. After 4-6 hours at room temperature, the resulting suspension is subjected to solid-liquid separation. The powder obtained after washing and drying the solid is calcined in an inert gas to obtain the multi-metal composite nitrogen-carbon combustion rate catalyst.

[0010] In the above preparation method, preferably, the molar ratio of the transition metal element in the soluble salt of the transition metal to the rare earth metal element in the soluble salt of the rare earth metal is 1:9 to 19, the molar ratio of Na4[Fe(CN)6] to the transition metal element in the soluble salt of the transition metal is 12 to 15:1, and the molar ratio of Na4[Fe(CN)6] to the rare earth metal element in the soluble salt of the rare earth metal is 1 to 2:1.

[0011] In the above preparation method, the soluble salt of the transition metal is a nitrate of the transition metal, and the soluble salt of the rare earth metal is a nitrate of the rare earth metal.

[0012] In the above preparation method, the inert gas is argon.

[0013] In the above preparation method, it is further preferred that the calcination temperature is 300-800℃, the time is 1-6h, and the heating rate is 1-5℃ / min.

[0014] The beneficial effects of this invention are as follows:

[0015] This invention utilizes transition metal ion doping technology to dope rare earth metal ferrocyanates, leveraging the tunable nature of the Prussian blue framework to modify its chemical composition and structure, thereby synthesizing a novel composite combustion rate catalyst with excellent performance and mass production capability. The multi-metal composite combustion rate catalyst of this invention uses carbon materials as a support. Through the synergistic effect between transition metals and rare earth metals, the multiple metals influence and complement each other, fully utilizing the advantages and catalytic performance of the multi-metal composite structure. This invention obtains a sheet-like multi-metal composite nitrogen-carbon combustion rate catalyst by calcining a rare earth metal-doped Prussian blue analogue with transition metals at high temperature. The sheet diameter is approximately 300–500 nm. By doping with transition metals to adjust the morphology, the specific surface area of ​​the Prussian blue framework is increased, exposing more active sites, thus improving the catalytic performance for AP combustion in a simple and effective way. Attached Figure Description

[0016] Figure 1 This is a scanning electron microscope image of the cobalt-doped terbium ferrocyanate-derived polymetallic composite nitrogen-carbon (Co-Tb-N-doped polymetallic carbon materials, Co-Tb-NCM) composite combustion rate catalyst in Example 1.

[0017] Figure 2 Differential scanning calorimetry (DSC) curves of the multi-metal composite nitrogen-carbon combustion rate catalyst prepared by adding 5 wt.% of AP in Examples 1-4 and pure AP.

[0018] Figure 3 Differential scanning calorimetry (DSC) curves are obtained for pure AP, AP with the addition of 5 wt.% of the multi-metal composite nitrogen-carbon combustion rate catalyst prepared in Examples 5-8, and pure AP.

[0019] Figure 4 Differential scanning calorimetry (DSC) curves are obtained for pure AP, AP with the addition of 5 wt.% of the multi-metal composite nitrogen-carbon combustion rate catalyst prepared in Examples 1, 5, 9, and 10, respectively, and pure AP.

[0020] Figure 5 Differential scanning calorimetry (DSC) curves are obtained for pure AP and AP prepared by adding 5 wt.% of comparative examples 1-4, respectively, and pure AP. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to these embodiments.

[0022] Example 1

[0023] 2.91 mg (0.01 mmol) Co(NO3)2·6H2O and 40.77 mg (0.09 mmol) Tb(NO3)3·6H2O were added to 40 mL of water to obtain solution A, in which the molar ratio of Co to Tb was 1:9. 48.40 mg (0.1 mmol) Na4[Fe(CN)6]·10H2O were added to 20 mL of water to obtain solution B. Solution A was then added dropwise to solution B using a dropper, and the mixture was stirred at 350 rpm for 2 hours to produce a pale green suspension. The centrifuge speed was then adjusted to 10000 rpm. Solid-liquid separation was performed by centrifugation for 3 minutes (pm). The product was washed three times with deionized water and once with anhydrous ethanol. The resulting solid was dried in a 60°C oven for 12 hours to obtain a light green powder. The powder was then placed in a quartz boat, which was placed in a small tube furnace under argon protection at a flow rate of 30 mL / min. The calcination temperature was 500°C, the holding time was 5 hours, and the heating rate was 5°C / min. After calcination, the product was removed from the tube furnace, yielding a cobalt-doped terbium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Co-Tb-NCM. Figure 1 It can be seen that the obtained multi-metal composite nitrogen-carbon combustion rate catalyst is in the form of sheets with a diameter of approximately 300–500 nm.

[0024] Example 2

[0025] In this embodiment, Tb(NO3)3·6H2O in Example 1 was replaced with an equimolar amount of Sm(NO3)3·6H2O, and the other steps were the same as in Example 1, to obtain a cobalt-doped samarium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Co-Sm-NCM.

[0026] Example 3

[0027] In this embodiment, Tb(NO3)3·6H2O in Example 1 was replaced with an equimolar amount of Eu(NO3)3·6H2O, and the other steps were the same as in Example 1, to obtain a cobalt-doped europium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Co-Eu-NCM.

[0028] Example 4

[0029] In this embodiment, Tb(NO3)3·6H2O in Example 1 was replaced with equimolar Dy(NO3)3·6H2O, and the other steps were the same as in Example 1, to obtain a cobalt-doped dysprosium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Co-Dy-NCM.

[0030] Example 5

[0031] In this embodiment, equimolar amounts of Cu(NO3)2·6H2O were used to replace Co(NO3)2·6H2O in Example 1, and the other steps were the same as in Example 1, to obtain a copper-doped terbium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Cu-Tb-NCM.

[0032] Example 6

[0033] In this embodiment, Tb(NO3)2·6H2O in Example 1 was replaced with an equimolar amount of Sm(NO3)3·6H2O, and the other steps were the same as in Example 5, to obtain a copper-doped samarium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Cu-Sm-NCM.

[0034] Example 7

[0035] In this embodiment, equimolar amounts of Eu(NO3)3·6H2O were used to replace Tb(NO3)2·6H2O in Example 1. The other steps were the same as in Example 5, resulting in a copper-doped europium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Cu-Eu-NCM.

[0036] Example 8

[0037] In this embodiment, Tb(NO3)2·6H2O in Example 1 was replaced with equimolar Dy(NO3)3·6H2O, and the other steps were the same as in Example 5, to obtain a copper-doped dysprosium ferrocyanate-derived multimetal composite nitrogen-carbon combustion rate catalyst, denoted as Cu-Dy-NCM.

[0038] Example 9

[0039] In this embodiment, equimolar amounts of Fe(NO3)3·9H2O were used to replace Co(NO3)2·6H2O in Example 1, and the other steps were the same as in Example 1, to obtain a multi-metal composite nitrogen-carbon combustion rate catalyst derived from iron-doped terbium ferrocyanate, denoted as Fe-Tb-NCM.

[0040] Example 10

[0041] In this embodiment, Co(NO3)2·6H2O in Example 1 was replaced with an equimolar amount of Mn(NO3)2·4H2O, and the other steps were the same as in Example 1, to obtain a manganese-doped terbium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Mn-Tb-NCM.

[0042] Comparative Example 1

[0043] 90.6 mg (0.02 mmol) of Tb(NO3)3·6H2O was added to 20 mL of water to obtain solution A; 96.8 mg (0.02 mmol) of Na4[Fe(CN)6]·10H2O was added to 20 mL of water to obtain solution B. Solution A was then added dropwise to solution B using a dropper, and the mixture was stirred at 350 rpm for 2 hours to produce a pale green suspension. Solid-liquid separation was performed by centrifuging at 10000 rpm for 3 minutes. The solid was washed three times with deionized water and once with anhydrous ethanol. The resulting solid was dried in a 60°C drying oven for 12 hours to obtain a light green powder. The powder was then placed in a quartz boat, which was placed in a small tube furnace. Argon gas was introduced for protection at a flow rate of 30 mL / min. The calcination temperature was 500°C, the calcination holding time was 5 hours, and the heating rate was 5°C / min. After calcination, the product was removed from the tube furnace to obtain a terbium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Tb-NCM.

[0044] Comparative Example 2

[0045] In this comparative example, Tb(NO3)3·6H2O in Comparative Example 1 was replaced with an equimolar amount of Sm(NO3)3·6H2O, and the other steps were the same as in Comparative Example 1, to obtain a samarium ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Sm-NCM.

[0046] Comparative Example 3

[0047] In this comparative example, Tb(NO3)3·6H2O in Comparative Example 1 was replaced with an equimolar amount of Eu(NO3)3·6H2O, and the other steps were the same as in Comparative Example 1, to obtain a europium ferrocyanide-derived multimetallic composite nitrogen-carbon combustion rate catalyst, denoted as Eu-NCM.

[0048] Comparative Example 4

[0049] In this comparative example, Tb(NO3)3·6H2O in Comparative Example 1 was replaced with an equimolar amount of Dy(NO3)3·6H2O. The other steps were the same as in Comparative Example 1, and a multi-metal composite nitrogen-carbon combustion rate catalyst derived from dysprosium ferrocyanide was obtained, denoted as Dy-NCM.

[0050] To demonstrate the beneficial effects of this invention, combustion catalytic performance was tested by adding 5 wt.% of the multi-metal composite nitrogen-carbon combustion rate catalysts prepared in Examples 1-10 to AP, respectively. The results are shown below. Figures 2-4 Meanwhile, comparative experiments were conducted on the combustion catalytic performance of the multi-metal composite nitrogen-carbon combustion rate catalysts obtained in Comparative Examples 1-4, and the results are shown in [the table below]. Figure 5 .

[0051] from Figure 2It can be seen that, under the same conditions, after adding 5 wt.% of the cobalt-doped rare earth metal ferrocyanate-derived multimetal composite nitrogen-carbon combustion rate catalyst prepared in Examples 1-4 to the main component AP of the solid propellant, the peak temperature of AP in the high-temperature decomposition stage decreased from 402.3℃ to 301.1℃, 319.7℃, 318.7℃, and 319.7℃, respectively, and the apparent heat of decomposition of AP decreased from 679.81 J·g -1 Increased to 1415.66 J·g -1 1532.99 J·g -1 1462.77 J·g -1 1416.54 J·g -1 The increases were 735.85 J·g respectively. -1 853.18 J·g -1 782.96 J·g -1 782.73 J·g -1 Among them, the cobalt-doped terbium ferrocyanate-derived polymetallic composite nitrogen-carbon combustion rate catalyst showed the highest degree of advancement in the high-temperature decomposition peak temperature of AP, and the most concentrated exothermic peak. This indicates that the addition of 5 wt.% of the polymetallic composite nitrogen-carbon combustion rate catalyst prepared in Examples 1-4 to AP has a significant catalytic effect on AP decomposition, with the high-temperature decomposition peak temperature of AP shifting forward and the exothermic heat also increasing significantly.

[0052] from Figure 3 It can be seen that, under the same conditions, after adding 5 wt.% of the copper-doped rare-earth metal ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst prepared in Examples 5-8 to the main component AP of the solid propellant, the decomposition peak temperature of AP was significantly reduced. The high-temperature decomposition peak temperature of AP decreased from 402.3℃ to 303.6℃, ​​304.8℃, 310.7℃, and 303.4℃, respectively, and the apparent heat of decomposition of AP decreased from 679.81 J·g -1 The concentration increased to 1357.36 J·g. -1 1278.63 J·g -1 1277.96 J·g -1 1123.35 J·g -1 The increases were 677.55 J·g respectively. -1 598.82 J·g -1 598.15 J·g -1 443.54 J·g -1 .

[0053] from Figure 4It can be seen that, under the same conditions, after adding 5 wt.% of the transition metal-doped terbium ferrocyanate-derived multimetal composite nitrogen-carbon combustion rate catalyst prepared in Examples 1, 5, 9, and 10 to the solid propellant main component AP, the high-temperature decomposition peak temperature of AP decreased from 402.3℃ to 301.1℃, 303.6℃, ​​311.5℃, and 313.0℃, respectively, and its apparent decomposition heat decreased from 679.81 J·g⁻¹, respectively. -1 Increased to 1415.66 J·g -1 1357.36 J·g -1 1479.20 J·g -1 1344.35 J·g -1 The increases were 736.73 J·g respectively. -1 677.55 J·g -1 799.39 J·g -1 664.54 J·g -1 .

[0054] from Figure 5 It can be seen that, under the same conditions, after adding 5 wt.% of the multi-metal composite nitrogen-carbon combustion rate catalyst prepared in Comparative Examples 1-4 to the main component AP of the solid propellant, the peak temperature of AP in the high-temperature decomposition stage decreased from 402.3℃ to 322.8℃, 317.4℃, 311.5℃, and 320.7℃, respectively, and the apparent heat of decomposition of AP decreased from 679.81 J·g -1 Increased to 1202.63 J·g -1 1351.83 J·g -1 1493.50 J·g -1 1391.76 J·g -1 The increases were 522.82 J·g respectively. -1 672.02 J·g -1 813.69 J·g -1 711.95 J·g -1 .

[0055] Comparing the catalytic effects of the cobalt-doped rare-earth ferrocyanate-derived polymetallic composite nitrogen-carbon combustion rate catalysts prepared in Examples 1-4 with those prepared in Examples 5-8 on AP, considering the high-temperature decomposition peak temperature and apparent heat release of AP, the cobalt-doped terbium ferrocyanate-derived polymetallic composite nitrogen-carbon combustion rate catalyst exhibits a sharper and more concentrated heat release peak, indicating that the cobalt-doped terbium ferrocyanate-derived polymetallic composite nitrogen-carbon combustion rate catalyst has the best catalytic effect on the thermal decomposition of AP. Comparing the single rare-earth metal ferrocyanate-derived polymetallic composite nitrogen-carbon combustion rate catalysts of Examples 1-4 with the cobalt-doped rare-earth ferrocyanate-derived polymetallic composite nitrogen-carbon combustion rate catalysts of Examples 1-4, the cobalt-doped terbium ferrocyanate-derived polymetallic composite nitrogen-carbon combustion rate catalyst synthesized by incorporating cobalt into the terbium ferrocyanate-derived polymetallic composite nitrogen-carbon combustion rate catalyst exhibits superior apparent heat release and concentrated heat release. The high-temperature decomposition peak temperature of AP is advanced to 301.15℃, which is significantly better than that of the single rare-earth metal ferrocyanate-derived composite polymetallic nitrogen-carbon material. Considering both the decomposition peak temperature and apparent heat release, the performance and application prospects of the single rare-earth metal ferrocyanate-derived polymetallic composite nitrogen-carbon material are significantly better than those of the transition metal-doped rare-earth ferrocyanate-derived polymetallic composite nitrogen-carbon material.

Claims

1. The application of a transition metal-doped rare earth ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst in the combustion catalysis of ammonium perchlorate, characterized in that: The combustion rate catalyst is a multi-metal composite nitrogen-carbon material obtained by calcining a Prussian blue analogue of a transition metal doped with a rare earth metal. The transition metal is any one of copper, cobalt, iron, and manganese; The rare earth metal is any one of terbium, samarium, europium, and dysprosium; The preparation method of the combustion rate catalyst is as follows: a mixed aqueous solution of soluble salts of transition metals and soluble salts of rare earth metals is added dropwise to a saturated aqueous solution of Na4[Fe(CN)6]. After 4-6 h at room temperature, the resulting suspension is subjected to solid-liquid separation. The powder obtained after washing and drying the solid is calcined in an inert gas to obtain the multi-metal composite nitrogen-carbon combustion rate catalyst. The molar ratio of the transition metal element in the soluble salt of the transition metal to the rare earth metal element in the soluble salt of the rare earth metal is 1:9 to 19, the molar ratio of Na4[Fe(CN)6] to the transition metal element in the soluble salt of the transition metal is 12 to 15:1, and the molar ratio of Na4[Fe(CN)6] to the rare earth metal element in the soluble salt of the rare earth metal is 1 to 2:

1.

2. The application of the transition metal-doped rare earth ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst according to claim 1 in the combustion catalysis of ammonium perchlorate, characterized in that: The transition metal is cobalt, and the rare earth metal is terbium.

3. The application of the transition metal-doped rare earth ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst according to claim 1 in the combustion catalysis of ammonium perchlorate, characterized in that: The particle size of the multi-metal composite combustion rate catalyst is 300–500 nm.

4. The application of the transition metal-doped rare earth ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst according to claim 1 in the combustion catalysis of ammonium perchlorate, characterized in that: The soluble salts of the transition metals are nitrates of the transition metals, and the soluble salts of the rare earth metals are nitrates of the rare earth metals.

5. The application of the transition metal-doped rare earth ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst according to claim 1 in the combustion catalysis of ammonium perchlorate, characterized in that: The inert gas is argon.

6. The application of the transition metal-doped rare earth ferrocyanate-derived multimetallic composite nitrogen-carbon combustion rate catalyst according to claim 1 in the combustion catalysis of ammonium perchlorate, characterized in that: The calcination temperature is 300–800 °C, the holding time is 1–6 h, and the heating rate is 1–5 °C / min.

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