Decomposition Of Ammonium Perchlorate Research Articles

Synthesis, structure, and AP catalytic performance of two new 1D coordination polymers

Two 1D chain coordination polymers (CPs), [Co(DNDPA)(DMF)2] 1 and [Mn(DNDPA)(DMF)2] 2, were successfully synthesized (4,4′-dinitrodiphenic acid, DNDPA). Their structures were confirmed by single-crystal X-ray diffraction. Differential scanning calorimetry coupled with thermogravimetric analysis revealed that both CPs exhibit commendable thermal stability, with CP 1 and 2 decomposing at 368.9 °C and 375.5 °C, respectively. Non-isothermal kinetic studies confirmed that both CPs displayed significant catalytic activity for the decomposition of ammonium perchlorate (AP). In particular, CP 1 and 2 reduced the activation energy of AP from its intrinsic value to 100.5 kJ/mol and 127.45 kJ/mol, respectively, and its high-temperature decomposition peak to 354.3 °C and 327.7 °C, respectively. These findings underscore the potential of these CPs as effective catalysts for enhancing the combustion properties of AP.

The bimetallic 3,5-dinitrobenzoate composites: A flexible-synergistic catalysts for high-performance decomposition of ammonium perchlorate

Composites of metal complexes have catalytic effects on the thermal decomposition of ammonium perchlorate (AP), while the kinetics and mechanism studies of the processes are seldom mentioned. Here, composite microspheres of cupric 3,5-dinitrobenzoate and cobalt 3,5-dinitrobenzoate [(3,5-DNB)Cox•Cuy] were synthesized and employed to research the kinetics and mechanism of AP catalytic decomposition. The decomposition peak temperature of AP in the presence of the (3,5-DNB)Cox•Cuy microspheres decreased from 403 °C (pure AP) to 288 °C, and the released heat increased by 384.5–745.6 J/g. Notably, the (3,5-DNB)Cox•Cuy microspheres significantly improved the kinetic rate constant by 1.83–37.75 times. The (3,5-DNB)Cox•Cuy microspheres exhibited higher activity than their corresponding single components for the thermal decomposition of AP, indicating excellent synergistic effects and proposing a possible mechanism. Understanding the kinetics and mechanism of the catalytic process developed in this study could further improve the decomposition performance of AP.

Ammonium perchlorate catalyzed with novel n-Al modified on ZIF-67 with silane coupling agent: Superior catalytic activity, advanced decomposition kinetics and mechanisms

Ammonium perchlorate (AP) is commonly utilized as an oxidizer in composite solid propellants (CSPs), and the thermal decomposition of AP has a significant impact on the combustion behaviour of CSPs. Aluminum nanoparticles (n-Al) as a prospective metal fuel have received a lot of interest, however properly extracting energy from n-Al remains a great challenge. Native oxide layer limits the energetic performance of n-Al by impeding sufficient combustion and slowing down mass/heat transport. Development of the high energy storage based on metastable intermolecular composite (MIC) is always a desirable way. This group of hybrid materials uses zeolitic imidazole framework (ZIF) as the precursors of the metal oxides as the oxidizers in conventional nanothermite. Coating n-Al on the surface of ZIF-67 with a silane coupling agent to erase or disturb the oxide layer on the n-Al surface improves n-Al combustion. n-Al@ZIF-67 was synthesized and integrated into AP matrix. The catalytic activity of n-Al@ZIF-67 on AP decomposition was assessed via DSC and TGA/DTG. Whereas n-Al@ZIF-67/AP nanocomposite demonstrated decomposition enthalpy of 2350 J/g; pure AP demonstrated 836 J/g, ZIF-67/AP demonstrated 1680 J/g, and n-Al/AP demonstrated 1170 J/g. While Al@ZIF-67/AP nanocomposite demonstrated one decomposition temperature at 327 oC; pure AP decompose at two decomposition stages at 298 oC, and 453 oC. n-Al@ZIF-67/AP showed a violent reaction with high intensity of flame, and micro-explosion occurred due to rapidly disrupted oxide layer that covered Al core. Decomposition kinetics was investigated. n-Al@ZIF-67/AP demonstrated apparent activation energy of 125.3 ± 1.23 kJ/mol compared with 173.16 ± 1.95 kJ/mol for pure AP. Co3O4 NPs as the combustion product from ZIF-67 can expose active surface sites; the ability of adsorption of released NH3 gas, which inhibition AP from decomposition, offering efficient combustion. This work provides a new strategy for advanced CSPs by introducing ZIF-67 to construct bifunctional properties for AP decomposition, and n-Al combustion.

Selective Conversion of Thermal Decomposition Products of Ammonium Perchlorate by Amorphous CoSnOx

The directional transformation of products in the multiphase decomposition process of ammonium perchlorate (AP) still faces significant challenges, one of which is the conversion of greenhouse gas N2O. Furthermore, additional elucidation of the structure and potential catalytic mechanisms of catalysts with high thermal stability is imperative for the aforementioned process. This study proposes a cobalt-based amorphous oxide with high thermal stability for catalysing the thermal decomposition of AP and achieving the transformation of catalytic products from N2O to NO (its derivatives). The results indicate that the type of catalytic decomposition products is related to the structural transformation of the catalyst, suggesting a synergistic oxidation mechanism by active oxygen and lattice oxygen. The peak decomposition temperature of AP has dropped to near the limit of 257.2 ° C, TG-IR test and MD simulation results indicate the selective generation of NO under the lattice oxygen mechanism. In addition, kinetic calculations elucidated the transition of catalysts from amorphous to crystalline state in catalysis. Finally, suggestions were made for the current characterization techniques of catalysts. This study offers a reference point for the catalyst design of AP decomposition-oriented products, which is beneficial for the transition to more environmentally-friendly products.

High-performance ammonium perchlorate propellants enabled by ferrocene-functionalized carbon nanotube catalysts

Ferrocene-based burning rate catalysts (BRCs) are essential for controlling the combustion of ammonium perchlorate (AP)-based composite solid propellants. However, their efficacy is often limited by migration during storage, leading to performance degradation. This work reports a novel class of covalently grafted ferrocene-functionalized multi-walled carbon nanotubes (CNT-Fc-n, n = 1, 2, 3) exhibiting enhanced catalytic activity and anti-migration properties. Structural characterization confirmed successful functionalization, while electrochemical analysis revealed facilitated electron transfer during AP decomposition due to π-π conjugation within the CNT-Fc-n structure. Consequently, CNT-Fc-n catalysts significantly reduced the AP decomposition activation energy, with CNT-Fc-3 (highest ferrocene loading) demonstrating the most pronounced catalytic effect. Specifically, CNT-Fc-3 lowered the AP decomposition temperature by 103 °C and 39 °C compared to pure AP and Catocene-catalyzed AP, respectively. Kinetic analysis revealed a 28-fold increase in the rate constant for CNT-Fc-3 catalyzed AP decomposition compared to pure AP. Moreover, the unique architecture of CNT-Fc-3 significantly reduced migration during a 50 °C simulation. This work presents a promising strategy for developing high-performance, migration-resistant BRCs for next-generation solid propellants.

Evaluation of the synergistic effect of magnetic nanoparticles and Ferrocene-Based 1,2,3-Triazolyl compounds as burning rate catalysts for solid rocket Motors

This work reports the synthesis, characterization, and application of promising nanocatalysts on the thermal decomposition of ammonium perchlorate (AP). Magnetite nanoparticles were functionalized with Ferrocene-derivative groups through chemical and physical methods to obtain these composite materials. The characterization was done using TEM, FTIR, VSM, and TGA techniques. The composite material MNP-Fc2I causes a decrease in the high-temperature decomposition (HTD) of AP to 357 °C. On the other hand, the MNP-Fc1 obtained the lowest activation energy (138 kJ·mol−1), indicating that the reaction may initiate at a relatively high temperature due to the need to overcome the activation energy barrier; once it begins, it proceeds with reduced energy requirements. Furthermore, performing ion exchange with energetic anions results in a decrease in the decomposition temperature of AP for the MNP-Fc1(N3) and MNP-Fc1(DCA) catalysts.

Synthesis, crystal structure, and thermal properties of energetic complex Cu(II) and Ag(I) based on 3-amino-4-(4,5-diamino-1,2,4-triazole-3yl)-furazan

High nitrogen compounds have received much attention due to their great potential as high energy density materials, and the selection of high nitrogen heterocyclic rings as ligands for energetic coordination compounds (ECCs) play a leading role in regulating the energy properties of ECCs. Furazan is rarely used as a building block for the development of high-energy metal ligands. In this study, a new type of high nitrogen ligand 3-amino-4-(4,5-diamino-1,2,4-triazole-3yl)-furazan (ATF) was selected and four kinds of high energy coordination polymers [Cu(II)(ATF)2·4H2O](NO3)2·2H2O (1), [Cu(II)(ATF)2·4H2O](ClO4)2·2H2O (2), [Ag(I)(ATF)2]ClO4·H2O (3) and [Ag(I)(ATF)2NO3] (4) were prepared by water solvent volatilization method and characterized for the first time. The single crystal XRD confirmed that there were abundant hydrogen bond interactions in the four complexes, resulting in dense aggregation with densities of 1.680 ∼ 2.089 g·cm−3. Meanwhile, theoretical calculations show that the detonation velocities of the four ECCs, 7578 ∼ 8192 m·s−1. In terms of thermal stability, the decomposition temperatures of the four ECCs (Td: 253 ∼ 288 °C) showed higher thermal stability during the rapid heating process than the reported ECCs (Cu(PZCA)2(ClO4)2, [Ag+(daf)NO3−]n and CHHP). Both shock and friction sensitivities are greater than 20 J and 300 N. This new structural motif is a promising high-energy material. Moreover, they can promote the combustion decomposition of ammonium perchlorate (AP) well, and the promotion effect of 1 and 2 is better than that of 3 and 4. In the field of explosives and propellants, four ECCs can be attractive candidates.

Facile boosting catalytic thermal decomposition of ammonium perchlorate from 3D porous nano Co3O4@ZnO composites

The design of efficient catalysts for the pyrolysis of ammonium perchlorate (AP) is important for the performance of composite solid propellants. Co3O4@ZnO heterojunction composites were fabricated by hydrothermal and calcination treatments and used to promote the thermal decomposition of AP. The influences of the Co/Zn molar ratio on the catalytic performance and the content of decomposition products of AP were investigated by various techniques such as TEM, XPS, BET, EIS, and TG-IR. The results revealed that the Co/Zn = 3 sample exhibited excellent performance with the high-temperature decomposition (HTD) temperature of AP reduced from 410°C to 295 °C and the apparent activation energy decreased to 98.7 kJ/mol in the case of 2 wt% addition, attributed to the construction of a heterojunction with abundant active sites enhancing the charge transfer capability between the Co3O4 and ZnO. The decomposition pathway of AP is influenced by the catalyst components, and the Co/Zn = 3 nanostructures demonstrated outstanding catalytic performance by accelerating the decomposition of HClO4 and the conversion of NH3, and promoting the production of N2O, NO, and NO2. This work provides a feasible strategy for the development of Co3O4@ZnO catalysts with excellent catalytic activity towards AP.

Mass Velocity Profiles for Non-Ideal Detonation of Mixtures of Nitromethane and Ammonium Perchlorate Overloaded with Aluminum. Measurements and Calculation

Earlier, by comparing the results of mathematical modeling with experimental data on the non-ideal detonation velocities of triple mixtures of nitromethane and ammonium perchlorate with aluminum excess, the rates of exothermic reactions and the consumption degree of components within the detonation wave reaction zone were determined. A quasi-one-dimensional model of steady detonation was used for calculations, in which all components have a common pressure and move with a common mass velocity, and exothermic conversion is carried out in three stages, which include decomposition of nitromethane and ammonium perchlorate and diffusion combustion of aluminum. To confirm the obtained results and the applicability of the relatively simple theoretical model, calculations of the mass velocity profile during detonation of one of the triple mixtures with 17% nitromethane have been carried out. The calculation results are in agreement with the measured mass velocity profile, concerning the shape of the profile, the amplitude and the rate of decrease of the mass velocity along the detonation reaction zone. A possible explanation of a “leaning” of the beginning portion of the mass velocity profile observed in experiments has been proposed, and an estimate of the rise time of the sensor signal is given, taking into account the calculated curvature of the shock front of the detonation wave.

Dispersion of nanocatalytic materials: a new strategy to explore the best catalytic performance for the thermal decomposition of multiple size ammonium perchlorate

Dispersion of nanocatalytic materials: a new strategy to explore the best catalytic performance for the thermal decomposition of multiple size ammonium perchlorate

Control of burning rate pressure sensitivity for solid propellants by changing the interfacial contact of Al/HMX/AP with precisely located graphene-based energetic catalysts

The control of burning rate pressure sensitivity is essential for stable and reliable combustion of solid propellants. It has been proved that the combustion behavior of propellants can be effectively tuned by interfacial control of Al/oxidizers. In this work, core-shell Al-based composites, using oxidizers such as ammonium perchlorate (AP) and cyclotetramethylene tetranitramine (HMX) as the shell layer, have been prepared with a well-controlled location of graphene-based carbohydrazide complexes (GO-CHZ-M, M = Co2+ or Ni2+) as the catalysts. The catalysts can be located inside HMX or embedded on the surface of AP particles. The decomposition of AP and HMX could be greatly promoted with a trace amount of catalyst. Under the synergistic effects of Al/oxidizer interfacial control and GO-CHZ-M, the ignition delay time is shortened by >48 % with increased in flame radiation. More importantly, the burning rate (r) and pressure exponent (n) of the solid propellants are effectively regulated in a wide range. In particular, the use of Al@HMX/Co results in a lowered n of 0.29 within 1∼20 MPa compared to 0.79 for the blank reference sample. The agglomeration of Al particles during combustion was also inhibited due to the micro-explosion effect of Al@HMX composites. Novelty and Significance statementThe innovative approaches of integrating Al/HMX/AP composites and precise catalysis of graphene-based energetic catalysts in solid propellants have successfully achieved, regarding the modulation of the burning rates and pressure sensitivity. Moreover, the effect of catalyst location on the ignition delay and burning rates has also been studied thoroughly and clarified. This paper provides new insight into the regulation of combustion performance of solid propellants, with improved reaction efficiency and maintained energy density.

Insights into the Fragmentation of Aluminum Hydride and Its Effect on Combustion and Agglomeration of HTPB Propellant.

AlH3 has gained considerable attention as a fuel additive due to its ability to offer high specific impulse and superior combustion performance. However, few studies have focused on the fragmentation and agglomeration behavior of AlH3. This study investigated the effects of fragmentation of AlH3 and AlH3/PVDF particles on the thermal decomposition, ignition, agglomeration, and combustion of HTPB propellants. Thermal analysis indicated that AlH3 and AlH3/PVDF can accelerate the decomposition of ammonium perchlorate by abundant active sites for the adsorption of the decomposition intermediates. Single-particle combustion uncovered the mechanism behind the directional spray of molten Al from the AlH3 particle and the fragmentation of the AlH3/PVDF particle. The melting of porous Al induces particle shrinkage due to solid-liquid interfacial tension and the structural restoration of the oxide shell, which consequently results in the sealing of cracks in the oxide shell of AlH3. Additionally, the accumulation of internal tensile stress leads to the reopening of these cracks and the directional ejection of the molten Al. The flexible oxide shell contributes to a smaller minimum normalized diameter of the AlH3/PVDF particle, aiding in the generation of internal tensile stress, while the sublimation of AlF3 induced the fragmentation. Synchrotron-based X-ray imaging revealed the formation of aggregates promoted by molten Al, the splitting of AlH3 aggregates due to hydrogen explosion, and the enhanced fragmentation of AlH3/PVDF due to the synergistic effect of hydrogen explosion and the sublimation of AlF3. Compared to raw particles, the CCPs (condensed combustion products) of SP2 propellant display a 48% reduction in average size (D50 = 24.5 μm), whereas there is an over 89% decrease in particle size for the CCPs of SP3 propellant (D50 = 5.14 μm). This study contributes to understanding the fragmentation of AlH3 and AlH3/PVDF upon ignition and combustion, providing valuable insights for the development and optimization of propellants containing AlH3.

Modeling adsorption reactions of ammonium perchlorate on rutile and anatase surfaces.

In this work, the effects of two TiO2 polymorphs on the decomposition of ammonium perchlorate (NH4ClO4) were studied experimentally and theoretically. The interactions between AP and various surfaces of TiO2 were modeled using density functional theory (DFT) calculations. Specifically, the adsorption of AP on three rutile surfaces (1 1 0), (1 0 0), and (0 0 1), as well as two anatase surfaces (1 0 1), and (0 0 1) were modeled using cluster models, along with the decomposition of adsorbed AP into small molecules. The optimized complexes of the AP molecule on TiO2 surfaces were very stable, indicating strong covalent and hydrogen bonding interactions, leading to highly energetic adsorption reactions. The calculated energy of adsorption (ΔEads) ranged from -120.23 to -301.98 kJ/mol, with highly exergonic calculated Gibbs free energy (ΔGads) of reaction, and highly exothermic enthalpy of reaction (ΔHads). The decomposition of adsorbed AP was also found to have very negative ΔEdec values between -199.08 and -380.73 kJ/mol. The values of ΔGdec and ΔHdec reveal exergonic and exothermic reactions. The adsorption of AP on TiO2 surfaces anticipates the heat release of decomposition, in agreement with experimental results. The most common anatase surface, (1 0 1), was predicted to be more reactive for AP decomposition than the most stable rutile surface, (1 1 0), which was confirmed by experiments. DFT calculations show the mechanism for activation of the two TiO2 polymorphs is entropy driven.

Construction of nanoflowers combustion catalyst NiO@g-C3N4 for improving thermal decomposition performance of AP

Thermal decomposition of ammonium perchlorate (AP) typically requires high temperatures and activation energy, but the introduction of combustion catalysts will improve its thermal decomposition performance. Therefore, it is crucial to rationally design combustion catalysts for enhancing the thermal decomposition performance of AP. Herein, 3D NiO nanoflowers@2D graphite-phase carbon nitride (g-C3N4) nanosheets (NiO@x%CN, x = 1, 3, 5, 7, 9) composite catalysts were constructed by solvothermal and calcination methods, and characterized by a series of analyses. NiO@5%CN displayed the best ability to catalyze the thermal decomposition of AP, which reduced the high decomposition temperature of AP by 113.8 °C and the activation energy by 21.67 kJ mol−1. The combustion rate of NiO@5%CN-CSP has increased by 118 % compared to that of composite solid propellants. This work provides a new insight for the design of NiO-based high-efficiency combustion catalysts.

Model-free kinetic analysis of multi-step thermal decomposition of ammonium perchlorate coated with reduced graphene oxide

Model-free kinetic analysis of multi-step thermal decomposition of ammonium perchlorate coated with reduced graphene oxide

Enhancement of aluminum powder reaction behavior at high temperatures—Aluminum powders with “sea urchin structure” coated by AP

To solve the problem of high ignition temperature of aluminum powder and easy to burn into blocks at high temperatures, “sea-urchin-structured” aluminum powders (μAl@nAl) obtained by electro-explosion were coated by ammonium perchlorate (AP) on its surface. AP in a high-temperature environment has a rapid decomposition, then the gas production will promote the dispersion of aluminum powder into micro-clusters, thus preventing the aluminum powder agglomeration during the combustion process. The micro-nano composite aluminum powder (μAl@8 %nAl) and physical mixed aluminum powder (μAl + 8 %nAl) coated by AP were completed by solvent volatilization method. The coating surface was observed by scanning electron microscopy. The heat of combustion and pressure curves for different AP contents were tested using a chamber with a constant volume, and the ignition and combustion performance of the AP samples were investigated using a carbon dioxide (CO2) laser ignition device. The AP samples shortened the ignition delay time and improved the combustion performance in the fixed-volume combustion and laser ignition tests. Under atmospheric air, taking into account the theoretical calorific value, pressure curve, and combustion performance, the optimal AP content is 10 %. The thermal decomposition process of two samples was further analyzed using the thermogravimetric and differential scanning calorimetry (TG-DSC) method. The decomposition of AP advanced the first oxidation peak of aluminum powder; however, in the second step oxidation peak, the peak temperature of μAl@8 %nAl@10 %AP sample was delayed compared to μAl + 8 %nAl@10 %AP sample. High-voltage electrical explosions and high-energy laser-induced air shock waves were created to simulate the high-temperature environment of the detonation reaction zone, and pictures of the reaction process and pressure change curves of the “sea urchin structure” aluminum powder coated by AP at high temperatures were recorded. The results showed that the “sea urchin structure” aluminum powder coated by AP exhibited better combustion performance, and the reaction degree of the aluminum powder had been deepened.

Cu/Carbon Aerogels Derived from HKUST-1 for the Thermal Decomposition of Ammonium Perchlorate

Cu/Carbon Aerogels Derived from HKUST-1 for the Thermal Decomposition of Ammonium Perchlorate

Preparation of Zn-Co Bimetallic Catalysts and Their Catalytic Properties for Thermal Decomposition of Ammonium Perchlorate.

This research delves into the preparation of heteronuclear bimetallic catalysts and explores their catalytic properties in the thermal decomposition of ammonium perchlorate (AP). The study's central focus is on enhancing the thermal decomposition characteristics of AP and, consequently, the combustion performance of composite solid propellants. The synthesized materials underwent structural characterization by XRD, XPS, SEM, and FTIR. Catalytic properties were examined using DTA tests. Notably, catalysts derived from calcination at 500 °C exhibited heightened catalytic activity. They advanced the pyrolysis temperature by 135.4 °C and reduced the activation energy by 82.38 kJ/mol compared with pure AP. To further elucidate the decomposition mechanism of AP, the investigation also employed a combined approach involving DSC-TG-FTIR-MS analysis.

Based on the strong oxidant AP adjustment strategy to obtain Al/AP@PVDF composite material with excellent energy release performance

In this paper, ammonium perchlorate (AP) as a strong oxidant has been added into Al/polyvinylidene difluoride (PVDF) nanothermites. Based on homogeneous structure of PVDF, shorter reaction contact between components can be obtained for more outstanding ignition and combustion performance. Water contact angle experiments were conducted to evaluate the hydrophobicity of the composite films, indicating that the suitability of composite material has enhanced under wet environment. According to TG-DSC results, the thermal decomposition of AP can improve the whole heat release process, which theoretically has excellent combustion performance advantages. Constant volume pressure tests were conducted to assess the energy release properties of the films compared with Al@PVDF films. Combustion performance in air was evaluated by employing optical sensors and a high-speed camera to measure factors such as the ignition delay time, light intensity and combustion flame propagation. After adding 15 % AP, the maximum pressure of Al/AP@PVDF film is 0.0960 Mpa, and that of Al@PVDF film is 0.0805 Mpa. The maximum pressure of the film is increased by nearly 19.25 %. Compared with Al@PVDF film, the ignition delay time of Al/AP@PVDF film is shortened by 45 ms, and the light intensity is increased by nearly 93.39 %. However, excessive AP content adversely impacted film formation efficiency, leading to the deterioration of various properties. Therefore, an optimal AP content of approximately 15 % in Al/AP@PVDF system was finally identified.

Energetic transition metal complexes based on 1‐allylimidazole and nitrocyanamide: Syntheses, characterizations and catalytic performances on the thermal decomposition of ammonium perchlorate

AbstractTo explore combustion catalysts for solid propellants, four novel energetic coordination compounds were prepared with the anion of nitrocyanamide (NCA) as the ligand and 1‐allyl‐imidazole (AIM) as the ligand, and transition metals Mn, Co, Ni, and Cu as the central ions. The structures of these compounds were [Mn(AIM)4] (NCA)2 (1), [Co(AIM)4](NCA)2 (2), [Ni(AIM)4](NCA)2 (3), [Cu(AIM)4](NCA)2 (4). The results showed that all of the compounds possessed high energy density, and compound 2 had a mass energy density (Eg) of 17.9 kJ g−1 and a volume energy density (Ev) of 25.59 kJ cm−3. The catalytic effect of these compounds on the thermal decomposition of ammonium perchlorate (AP) was studied using DSC. The addition of 5 % catalyst to AP samples advanced the high‐temperature decomposition temperature and significantly increased the heat release. Compound 4 exhibited the best catalytic performance, with an increased heat release of 1739 J g−1, decomposition temperature advanced by 88.2 °C, and activation energy reduced to 74.74 kJ mol−1. These results demonstrate the potential of these compounds as combustion catalysts for solid propellants.