High-temperature Decomposition Of Ammonium Perchlorate Research Articles

Two-dimensional cluster catalysts with superior thermal stability and catalytic activity for AP

The preparation of catalysts with small particle size, large specific surface area and high atomic utilization has always been the focus of research in the field of catalysis. As for energetic materials, catalysts are always used to improve the thermal decomposition performance of ammonium perchlorate (AP) as it has significant effect on the power of engine. In this work, a two-dimensional metal clusters catalyst has been successfully prepared by solvothermal and heat treatment to improve thermal decomposition performance of AP. In detail, the transition metal ions were supported on the graphene oxide (GO) surface by organic ligands linking, followed by heat treatment to obtain two-dimensional rGO based metal clusters catalyst. The morphology and structure of the catalysts at different temperatures and their effect on AP decomposition were studied, the results show that catalyst at 300 °C has a particle size of 20 nm and uniformly distributed on rGO. The catalyst promotes the high temperature decomposition of AP by 73.7 °C with improved stability, and increases the heat release from 652.73 J/g to 1392.11 J/g. This may be attributed to good conductivity of GO and the strong gain-loss electron ability of the metal clusters. The presence of GO increased the active sites for cluster catalysis, additional, the metal clusters have a positive synergistic effect with GO. Thus, the thermal decomposition performance of AP was enhanced meanwhile thermal stability can also be improved.

Preparation of TiO2/CNTs nanocomposite and its catalytic performance on the thermal decomposition of ammonium perchlorate

Composite particles of carbon nanotubes (CNTs) and titanium dioxide (TiO2) were prepared by a sol-flux method. Characterization of TiO2/CNTs nanocomposite was performed by X-ray powder diffraction (XRD), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The results show that TiO2 nanocrystals (mixed anatase and rutile) are successfully deposited on the surface of CNTs, forming a granular coating with a thickness of about 2 nm. It is possible that the growth of TiO2 on the surface of CNTs is implemented by anchoring TiO2 through hydroxyl and carboxylic functional groups. In the presence of TiO2/CNTs nanocomposite, the peak temperature of the high-temperature decomposition of ammonium perchlorate (AP) decreased by 52.5 °C, better than other samples including the one of simply mixed TiO2 and CNTs. The catalytic influence is evident even with 1% catalyst concentration. The thermal kinetic constant for the catalytic decomposition of AP is computed using model free (isoconversional) Flynn–Wall–Ozawa approach. It shows that although the two exothermic decomposition peaks merged into one, the low-temperature decomposition stage still exists, and accounts for about thirty percent of the whole reaction.

Formation of composite fuels by coating aluminum powder with a cobalt nanocatalyst: Enhanced heat release and catalytic performance

Aluminum (Al) and Cobalt (Co) materials are used as a metal fuel and a burning rate catalyst in solid propellants, respectively. However, micro-sized Al fuel has a poor heat release performance because of inertial surface oxide layers, and a nano-sized Co catalyst tends to agglomerate due to high surface energy and magnetism. In this work, we successfully synthesize a new composite fuel by coating Al fuel with a Co catalyst (Co/Al) via a novel replacement reaction and experimentally investigate its heat release and catalytic performance. Our measurements show that the heat release efficiency of Al powder is greatly enhanced by coating only 4.6 wt% of Co. The high oxidation temperature of the formed composite fuel is advanced by 112 °C, and the heat release is approximately 1.5 times that of the raw Al. The Co/Al composite fuel displays excellent catalytic activity and stability toward the thermal decomposition of ammonium perchlorate (AP), thereby decreasing the high decomposition temperature of AP by approximately 150 °C. To the best of our knowledge, the promoting efficiencies of the high-temperature oxidation of Al and the high-temperature decomposition of AP are higher than those reported in literature. The heat release and catalytic thermal decomposition mechanisms of Co/Al composite fuel are proposed on the basis of experimental phenomena and results. Results confirm that the formation of composite fuel by coating Al powder with a Co nanocatalyst is an effective method to enhance the heat release of Al and the catalytic performance towards AP. The as-obtained Co/Al composite fuel is expected to have wide application prospects in solid propellants.

Further construction of MnO2 composite through in-situ growth on MXene surface modified by carbon coating with outstanding catalytic properties on thermal decomposition of ammonium perchlorate

In order to improve the dispersion of MnO2 particles and inhibit the self-oxidation of MXene, during MnO2/MXene preparation, MXene@C was firstly prepared before the hybridization of MnO2 and MXene. The coating of carbonaceous materials on the surface of MXene could not only provide carbon as reducing agent to KMnO4 for the in situ generation of MnO2 with controlled extent of reaction for good morphology obtaining, but more importantly, form the shielding layer to avoid MXene oxidation during the redox reaction. The structure and morphology of MnO2/MXene@C composite were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectra (XPS). The results indicated that the layer MXene was well protected and MnO2 particles with uniform particle size were well distributed on the surface of MXene. Furthermore, the catalytic property of MnO2/MXene@C composite on the thermal decomposition of ammonium perchlorate (AP) was evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). With the addition of 2 wt% MnO2/MXene@C composite, the high-temperature decomposition of AP was sharply decreased by 128.8 °C, which was higher than that of pure MXene and MnO2.

Preparation of Al/CuO/PG nanocomposite and catalytic effect on thermal decomposition of AP

ABSTRACTAl/CuO/PG nanocomposites were investigated in this paper as potential catalysts for the thermal decomposition of ammonium perchlorate (AP), where the high temperature decomposition of AP decreases from 424.4°C to 312.3°C, showing its strong catalytic activity on the thermal decomposition of ammonium perchlorate. In addition, the more the catalyst was added, the more the high-temperature decomposition temperature of AP decreased.

CuO nanoparticles supported on three‐dimensional nitrogen‐doped graphene as a promising catalyst for thermal decomposition of ammonium perchlorate

In the present work, CuO nanoparticles grown on three‐dimensional nitrogen‐doped graphene‐based frameworks (CuO@3D‐(N)GFs) were synthesized using a two‐step method. After the synthesis of three‐dimensional nitrogen‐doped graphene, CuO nanoparticles were deposited on it, by adding cupric acetate followed by thermal treatment. Different analysis methods were used to characterize the products. The as‐prepared nanocomposite was used as a promising catalyst for thermal decomposition of ammonium perchlorate (AP) as one of the most common oxidizer in composite propellants. Differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA) techniques were used to investigate the thermal decomposition of ammonium perchlorate. According to the DSC/TGA, high temperature decomposition of AP decreased to 111 °C in the presence of 4% CuO@3D‐(N)GFs and the total heat release (ΔH) from decomposition of AP increased to 1893 J g−1 which is much more than 590 J g−1 for pure AP.

Noncrystalline structure of Ni-P nanoparticles prepared by liquid pulse discharge.

Noncrystalline nickel phosphide (Ni-P) nanoparticles have drawn great attention due to their high potential as catalysts. However, the structure of noncrystalline Ni-P nanoparticles is still unknown, which may shed light on explaining the catalysis mechanism of the Ni-P nanoparticles. In this paper, noncrystalline Ni-P nanoparticles were synthesized. Their morphology, particle size, element contents, local atomic structures, as well as the catalysis in the thermal decomposition of ammonium perchlorate were studied. The results demonstrate that the as-prepared Ni-P nanoparticles are spherical with an average diameter of about 13.5 nm. The Ni and P contents are, respectively, 78.15% and 21.85%. The noncrystalline nature of the as-prepared Ni-P nanoparticles can be attributed to cross-linkage between P-doping f.c.c.-like Ni centers and Ni3P-like P centers. The locally ordered Ni centers and P centers are the nuclei sites, which can explain well the origin of initial nuclei to form the crystalline phases after high-temperature annealing. The starting temperature of high-temperature decomposition of ammonium perchlorate was found having a significant decrease in the presence of the noncrystalline Ni-P nanoparticles. Therefore, the as-prepared noncrystalline Ni-P nanoparticles can be used as a potential catalyst in the thermal decomposition of ammonium perchlorate.

Preparation of high filling ratio Fe 2 O 3 @MWCNTs composite particles and catalytic performance on thermal decomposition of ammonium perchlorate

Iron oxide-filled multi-walled carbon nanotubes (Fe2O3@MWCNTs) composite particles were produced by a mild and superior physical absorption method using molten Fe(NO3)3·9H2O as the precursor. Characterisation of Fe2O3@MWCNTs composite particles was performed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and thermogravimetry-differential scanning calorimetry. The results showed a large number of hematite phase Fe2O3 were uniformly filled in the MWCNTs, and the mass fraction of Fe2O3 was about 25.8 wt%. Furthermore, in the presence of 10 wt% Fe2O3@MWCNTs composite particles, the peak temperature of the high-temperature decomposition of ammonium perchlorate (AP) decreased by 116°C, the peak of the low-temperature decomposition disappeared and the amount of AP heat released was increased about 200 kJ/mol.

Effect of anatase–brookite mixed phase titanium dioxide nanoparticles on the high temperature decomposition kinetics of ammonium perchlorate

In the present study, titanium dioxide (TiO2) nanocatalyst was synthesized using a titanium alkoxide precursor. The nanocatalyst was found to consist of anatase and brookite phases, with an average particle size of ∼10 nm. Formation of the nanostructured anatase–brookite mixed phase TiO2 was confirmed by powder XRD and SAED studies. The nanocatalyst was further characterized by TEM, FTIR and thermogravimetry. Catalytic effect of the TiO2 nanocatalyst on the solid state thermal decomposition reaction of ammonium perchlorate (AP), a solid rocket propellant oxidizer, was evaluated. To evaluate the effectiveness of this nano TiO2 catalyst, the activation energy of the catalyzed decomposition reactions of AP was computed by a non-linear integral isoconversional method. The calculated activation energy value was then compared with that of non-catalyzed AP decomposition reactions. The catalyzed AP decomposition showed an unaffected low temperature decomposition (LTD) at the extent of conversion (α) between 0 and 0.30. Further, a characteristic slowdown and a nanocatalyst influenced high temperature decomposition (HTD) at α between 0.35 and 1 was observed. The possible reasons for the catalytic effect of TiO2 nanoparticles on the HTD of AP are discussed based on the fact that the exposed cations and anions on the transition metal oxide nanoparticle surface act as acid–base site pairs and adsorb gaseous reactive molecules formed during the LTD of AP.

SiO2 capsulized Cu active nanoparticles: synthesis and activity study

Cu active nanoparticles (Cu ANPs) were synthesized in weakly acidic solution to preserve their catalytic activity. SiO2 capsules were designed to insulate Cu ANPs from oxidation. The weak interaction between SiO2 capsules and Cu ANPs ensured that the designed nanoparticles had good anti-oxidation property and potentially high activity. The increased anti-oxidation property with thicker SiO2 capsules (Cus3 > Cus2 > Cus1) and the order of reactivity to oxygen (Cus1 = Cus2 > Cus3) showed that Cu ANPs with SiO2 capsules (Cus2) of appropriate thickness would be the best for application. By using the samples to construct non-enzymatic sensors, the detected activity toward electro-catalytic oxidation of glucose confirmed this conclusion. Dehiscence of SiO2 capsules recovered the activity of the Cu ANPs in the catalytic ammonium perchlorate (AP) decomposition process. With the addition of 1.5% of Cu ANPs, the high temperature decomposition of AP decreased by 184.2 °C.

Preparation of Carbon-Coated Nano-Fe, Co Particles and their Effects on the Thermal Decomposition of Ammonium Perchlorate

Nano Metal/C (Metal=Fe, Co) composite materials, in which nano iron and cobalt particles were uniformly distributed in carbon matrix, was prepared by pyrolysis of M-exchanged cation exchange resin(M-PAA). X-ray diffraction (XRD), Transmission Electron Microscope (TEM) results showed the particle size and morphology of nano iron and cobalt in M/C could be controlled by pyrolytic temperature. The particle size of Co and Fe in M/C obtained at 500 was respectively 15-40 nm and 10-35 nm. DTA was employed to test the thermal decomposition of ammonium perchlorate (AP) in the M/C and AP mixture. Results indicated the decomposition temperature at high-temperature decomposition of AP was lowered with the addition of amount of M/C-500, and the high temperature decomposition peaks of AP respectively lowered as much as 145.2°Cand 68.3°C with adding amount of 5% of Co/C and Fe/C obtained at 500 . The high and low temperature decomposition peaks of AP overlapped with addition of Co/C.

Nanoscale Additives Tailor Energetic Materials

The effect of anatase, rutile, and amorphous TiO2 nanoparticles on the combustion of solid rocket propellant was investigated. Each additive increased the burning rate of propellant strands by 30%. Typical fast-burning propellants are unstable due to oversensitivity to pressure variations, but the anatase additive yielded propellants with high yet stable burning rates over a broad pressure range. Anatase nanoparticles also catalyzed the high-temperature decomposition of ammonium perchlorate, a key component of solid propellant.

Effects of Nanometer Ni, Cu, Al and NiCu Powders on the Thermal Decomposition of Ammonium Perchlorate

AbstractA study of the decomposition behaviour for Ammonium Perchlorate(AP) was carried out by differential thermal analysis and the two decomposition peaks were observed. The high temperature peak was found to shift to lower temperatures, but the corresponding shift in the low temperature peak was smaller due to the effect of nanometer metal powders. Results shows that Cu and NiCu nanopowders decreased both the high and low decomposition temperature, while Ni and Al nanopowders just decreased the high decomposition temperature and increased the low decomposition temperature. Metal micron‐sized powders show catalytic effects on the thermal decomposition of AP, but their effects are less than that of nanometer metal powders. With the increase in content, nanometer metal powders enhanced their catalytic effect on the high temperature decomposition of AP, however their effect was weakened on the low temperature decomposition.

Thermal analysis of ammonium perchlorate +polystyrene +additive mixtures I

The thermolysis of ammonium perchlorate (AP) and AP/polystyrene propellants was investigated with carboxylates of copper as additives. The rate of burning was found to be enhanced considerably. TG and ignition delay studies demonstrated that the high-temperature decomposition of AP is enhanced enormously by these additives, whereas the low-temperature decomposition remains unaffected. It is suggested that the main species catalysing the rate of burning or AP decomposition is CuO. Analysis showed that the increase in the rate of burning is controlled by the catalysis of AP decomposition.

Mass-spectroscopic investigation of the kinetics of the high-temperature decomposition of ammonium perchlorate (APC)

Mass-spectroscopic investigation of the kinetics of the high-temperature decomposition of ammonium perchlorate (APC)

High-temperature decomposition of ammonium perchlorate and heterogeneous systems based on ammonium perchlorate

High-temperature decomposition of ammonium perchlorate and heterogeneous systems based on ammonium perchlorate

Use of a pulse mass spectrometer to investigate the high-speed processes associated with the high-temperature decomposition of ammonium perchlorate

Use of a pulse mass spectrometer to investigate the high-speed processes associated with the high-temperature decomposition of ammonium perchlorate