CuO nanocrystals in thermal decomposition of ammonium perchlorate

CuO nanocrystals of different surface areas were prepared. All samples were characterized by X-ray diffraction, transition electron microscope, thermogravimetry, Brunauer-Emmett-Teller technique, Fourier transform infrared spectroscopy, and Raman spectroscopy. CuO nanocrystals showed a stable monoclinic structure. With increasing surface areas, the surface hydration became significant, which is followed by shifts in infrared frequencies and Raman phonon modes. CuO nanocrystals were explored as an additive to catalytic decomposition of ammonium perchlorate (AP). AP decomposition underwent a two-stage process. Addition of CuO nanocrystals led to a downshift of high-temperature stage towards lower temperatures.     

Insight into the catalytic thermal decomposition mechanism of ammonium perchlorate

Journal of Thermal Analysis and Calorimetry -     

The thermal decomposition of doped ammonium perchlorate

The thermal decomposition of ammonium perchlorate doped with Cu²⁺, Mn²⁺, Co²⁺ and Fe³⁺ (with and without H⁺) was studied using DTA and TG. Small concentrations of these ions inhibit the decomposition by eliminating the first exothermic peak. At higher concentrations, a catalyzed decomposition is observed. Either the influence of the doping ions on the mechanism of the thermal decomposition is different from that of added oxides or a modification of the electron transfer mechanism is needed.     

Self-assembled CuO nanoarchitectures and their catalytic activity in the thermal decomposition of ammonium perchlorate

CuO shuttle-like and flower-like nanocrystals were synthesized through a one-step, low-temperature solution-phase method in the presence of a cation surfactant, hexadecyl trimethyl ammonium bromide. These nanocrystals were studied as an additive for promoting the thermal decomposition of ammonium perchlorate (AP). With the addition of CuO shuttle-like and flower-like nanocrystals, the thermal decomposition temperature of AP decreased. The structure, particle size, and morphology of resulting CuO powders were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Thermogravimetric analysis technique was applied to investigate the thermal decomposition of mixtures of AP and as-prepared CuO nanocrystals.     

The catalytic effect of rare earth oxides on the thermal decomposition of ammonium perchlorate

The kinetics of the decomposition of ammonium perchlorate (AP) in the presence of rare earth oxides, yttrium oxide (Y₂O₃) and lanthanum oxide (La₂O₃) as catalysts have been investigated. The Prout-Tompkins and contracting-cube equations have been found to fit the isothermal thermogravimetry data of catalysed AP decomposition. Gases evolved during catalytic decomposition of AP were analysed by infrared spectroscopy by matrix isolation technique. The mechanism of the catalysed thermal decomposition of AP has also been discussed in terms of an electron transfer process.

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Zusammenfassung Es wurde die Reaktionskinetik der thermischen Zersetzung von Ammoniumperchlorat (AP) in Gegenwart der Seltenerdenoxide Yttriumoxid (Y₂O₃) und Lanthanoxid (La₂O₃) als Katalysatoren untersucht. Zum Fitting der isothermen thermogravimetrischen Daten der katalysierten Zersetzung von AP läßt sich die Prout-Tompkins- und die Schrumpfwürfelgleichung erfolgreich anwenden. Die bei der katalytischen Zersetzung von AP freigesetzten Gase wurden durch IR-Spektroskopie untersucht. Der Mechanismus der katalytischen thermischen Zersetzung wurde auch vom Gesichtspunkt eines Elektronentransferprozesses aus besprochen.

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Radiation effects on thermal decomposition of ammonium perchlorate

Thermal decomposition of -irradiated (dose: 0–3.6 MGy) ammonium perchlorate was followed. The dynamic heating (range: 100–220 °C) and IR spectral measurements were carried out simultaneously. Temperature and dose brought a lowering in peak intensity of NH ₄ ⁺ and C10 ₄ ^– ions. Radiolytic products C10₃ and NH₃ are considered to initiate the decomposition process.     

Thermal decomposition of ammonium perchlorate activated via addition of NiO nanocrystals

This work reported on the thermal decomposition of ammonium perchlorate activated by addition of NiO nanocrystals with different surface areas. NiO samples were characterized by X-ray diffraction (XRD), transition electron microscope (TEM), Brunauer-Emmett-Teller (BET) technique, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. With increasing annealing temperature, the surface areas of NiO samples reduced from 108.6 to 0.9 m² g⁻¹. The catalytic activities of NiO nanocrystals on the thermal decomposition of ammonium perchlorate were investigated by thermogravimetric analysis (TG) coupled with differential thermal analysis (DTA). With addition of NiO nanocrystals, thermal decomposition temperature of AP decreased greatly. Larger surface areas of NiO nanocrystals promoted the thermal decomposition of AP.     

Evaluation of the catocene/graphene oxide nanocomposite catalytic activity on ammonium perchlorate thermal decomposition

A novel nanocomposite catalyst for thermal degradation of the ammonium perchlorate (AP) has been synthesized, and its effect on the thermal behavior of AP has been investigated. Preparation of the catalyst was carried out via functionalization of the graphene oxide with phenyl isocyanate and its noncovalent bonding to catocene. The catalytic activity of the catalyst was studied by thermal gravimetric analysis/differential scanning calorimetry at various heating rates. In addition, the effect of the catalyst on the AP thermal decomposition has been investigated by Kissinger and Friedman methods as two model-free methods for calculation of the activation energy parameter. According to the Kissinger method calculations, the E_a of AP decomposition reduced about 151 kJ⋅mol⁻¹ lower than the reported value for pure AP in the presence of the catalyst. Calculation of the E_a value for various reaction conversion rates by the Friedman method also confirmed the Kissinger method results.     

Effect of aluminum morphology on thermal decomposition of ammonium perchlorate

Journal of Thermal Analysis and Calorimetry - In this paper, two kinds of flake aluminum powder are prepared by bidirectional rotation mill using the spherical aluminum powder (Al-1) as raw...     

Thermal decomposition of ammonium perchlorate

This review represents an attempt to summarize literature data on thermal decomposition of ammonium perchlorate. The mechanism of thermal decomposition and various factors which influence on the thermal decomposition of ammonium perchlorate are discussed.     

Kinetics of ammonium perchlorate decomposition

The kinetic law of ammonium perchlorate decomposition in the presence and absence of metal oxides has been studied. Sublimation has also been considered from the kinetic point of view.

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Effects of different additives on the thermal decomposition of ammonium perchlorate

IR spectral investigations on ammonium perchlorate (AP) in the presence of varying amounts of ammonium permanganate (APm) and 2% by weight of different rare earth oxide additives were made over the temperature range 25–290°. Heating and spectral scanning were done simultaneously and the peak intensity was presumed to be proportional to the amount of undecomposed AP. Presence of 10% APm lowered the temperature of AP decomposition from 200 to 110° and increased the rate by several folds. Mixed oxide produced as a result of deflagration of APm are considered catalyzing the process. In the presence of rare earth oxides additives, the NH ₄ ⁺ stretching peak intensity decreased considerably, the extent followed the trend Gd₂O₃ > MnO₂ > Nd₂O₃ > Pr₂O₃ > Dy₂O₃ > Y₂O₃ > La₂O₃ > virgin AP. An electron transfer mechanism is envisaged to explain the results.     

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

Transition Metal Chemistry - Composite particles of carbon nanotubes (CNTs) and titanium dioxide (TiO2) were prepared by a sol-flux method. Characterization of TiO2/CNTs nanocomposite was performed...     

Thermal decomposition of doped ammonium perchlorate

Isothermal decomposition of orthorhombic ammonium perchlorate (AP) has been studied as a function of concentration of the dopants, SO ₄ ^2– and PO ₄ ^3– . In either case, the rate of decomposition passes through a maximum as the dopant concentration increases. Activation energy of the decomposition process remains unaltered by doping. The results are interpreted in terms of electron transfer mechanism.

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Zusammenfassung Die isotherme Zersetzung von orthorhombischen Ammoniumperchlorat (AP) wurde in Abhängigkeit von der Konzentration der Dopanten SO ₄ ^2– und PO ₄ ^3– untersucht. In jedem Falle geht die Geschwindigkeit der Zersetzung mit steigender Dopantenkonzentration durch ein Maximum. Die Aktivierungsenergie des Zersetzungsprozesses wird durch dopen nicht verändert. Die Ergebnisse werden auf einem Elektronentransfer-Mechanismus basierend interpretiert.

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The author is thankful to Dr. V. R. Pai Verneker of Indian Institute of Science, Bangalore, for stimulating discussions.     

Effect of catocene on the thermal decomposition of ammonium perchlorate and octogen

Simultaneous TG/DSC-FT-IR was employed to study the effect of catocene with a high concentration (5, 15, and 25 %) on the thermal decomposition of ammonium perchlorate (AP) and octogen (HMX) with different particle sizes. The experimental results show that catocene has effect on the thermal decomposition of AP and HMX, but the role that catocene playing changes with the concentration of catocene and the particle size of AP and HMX. High concentration of catocene (more than 15 %) benefits the decomposition of fine AP and HMX at low temperature, but has little effect on the decomposition of median and coarse AP. The thermal decomposition of HMX is affected by catocene mainly through increasing the heat release of the first decomposition step, while through both increasing the heat release and decreasing the decomposition temperature of the first decomposition step for the thermal decomposition of AP.     

The role of copper-chromium oxide catalysts in the thermal decomposition of ammonium perchlorate

The catalytic effects of doped or mixed CuO-Cr₂O₃ oxides on the thermal decomposition of ammonium perchlorate (AP) were investigated by using DTA, electrical conductivity and X-ray diffraction techniques. The results obtained revealed that the decrease in the defect electron of CuO catalyst doped with 1 at.% Cr³⁺ inhibited its activity, while the opposite effect was observed when Cr₂O₃ was doped with 1 at.% Cu²⁺. On increase of the concentrations of both oxides, the catalyst containing 70 at.% Cr³⁺ was found to be the most active during the decomposition of AP. The existence of CuCr₂O₄ at this ratio was demonstrated by X-ray diffraction. The activity of this spinel was explained on the basis of a hopping mechanism between Cr³⁺/Cr⁴⁺ active sites. Finally, the activation energies of different decomposition stages of AP alone and mixed with catalysts were calculated.

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Zusammenfassung Mittels DTA, Röntgendiffraktion und elektrischer LeitfÄhigkeit wurden die katalytischen Wirkungen von versetzten oder gemischten CuO-Cr₂O₃ Oxiden auf die thermische Zersetzung von Ammoniumperchlorat (AP) untersucht. Die erhaltenen Ergebnisse zeigen, da\ die Abnahme an Defektelektronen von CuO-Katalysator, versetzt mit 1 mol% Cr³⁺, seine AktivitÄt vermindern, wÄhrend ein entgegengesetzter Effekt bei Cr₂O₃ beobachtet wird, das mit 1 mol% Cu²⁺ versetzt ist.Durch Erhöhung der Konzentrationen beider Oxide zeigt der Katalysator bei der Zersetzung von AP die grö\te AktivitÄt bei einem Cr³⁺-Gehalt von 70 mol%. Mittels Röntgendiffraktion konnte bei dieser Zusammensetzung die Existenz von CuCr₂O₄ gezeigt werden. Die AktivitÄt dieser Spinellstruktur wurde durch einen Hüpfmechanismus zwischen Cr³⁺/Cr⁴⁺-aktiven Stellen erklÄrt. Weiterhin wurden die Aktivierungsenergien von verschiedenen Zersetzungsstufen von AP mit und ohne Katalysatoren berechnet.

     

Synthesis of dihydropyrazole‐bridged dinuclear ferrocenyl derivatives and their catalytic effect on thermal decomposition of ammonium perchlorate

Dihydropyrazole‐bridged dinuclear ferrocenyl derivatives (3a–3c) have been synthesized by the reaction of 1,3‐diferrocenyl‐2‐propen‐1‐on (1) with hydrazine, then acylation with acyl chloride directly. The structures were determined by mass spectrometry, IR and ¹H NMR spectroscopy. The compound 3c was characterized by single‐crystal X‐ray analyses. It was found that compounds 3a–3c have significant catalytic effect on the decomposition of ammonium perchlorate (AP). Compared with the thermal decomposition of pure AP, adding 3a, 3b and 3c in AP decreases its decomposition temperature by 78.8, 74.3 and 57.1 °C, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

A facile synthesis of boron nanostructures and investigation of their catalytic activity for thermal decomposition of ammonium perchlorate particles

In this research, ultrasound irradiation as a simple method was used to produce boron nanostructures. Reaction conditions such as boron concentration and sonication time show important roles in the size, morphology and growth process of the final products. The boron nanostructures (nanoparticles and nanorods) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, small-angle X-ray scattering and inductively coupled plasma atomic emission spectroscopy techniques. Primary evaluation of results showed that nanoparticles and nanorods of boron successfully have been prepared with 25–40 and 50–100 nm average particle size, respectively. These nanostructures (nanoparticles and nanorods) were studied as an additive for promoting the thermal decomposition of ammonium perchlorate (AP) particles. Thermochemical decomposition behaviors of treated samples were characterized by thermal gravimetric analysis and differential scanning calorimetry techniques. Also, the kinetic parameters of thermal decomposition processes of pure and treated samples were obtained by nonisothermal methods proposed by Kissinger and Ozawa. However, boron nanoparticles with the smallest average particle size (25–40 nm) have the most significant catalytic effect including the decrease in decomposition temperature of AP + B nanocomposite by 100 °C, increase in the heat of decomposition from 580 to 1354 J g^?1 and decrease in activation energy from 207 to 110 kJ mol^?1.     

Synthesis of CuO nanoparticles via one-pot wet-chemical method and its catalytic performance on the thermal decomposition of ammonium perchlorate

Sphere-like CuO products aggregated by numerous nanoparticles were fabricated by a low-temperature (50°C) wet chemical method using CuSO₄·5H₂O as precursor. The possible formation processes of CuO were investigated by a series of single-factor experiments. The CuO was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, selectedarea electron diffraction. Furthermore, the application of CuO nanoparticles on the thermal decomposition of ammonium perchlorate was studied with 2 wt % CuO nanoparticles at heating rates of 10, 15, 20, and 25°C min^–1 from 35 to 500°C.     

ZnO twin-cones: synthesis, photoluminescence, and catalytic decomposition of ammonium perchlorate

ZnO twin-cones, a new member to the ZnO family, were prepared directly by a solvothermal method using a mixed solution of zinc nitrate and ethanol. The reaction and growth mechanisms of ZnO twin-cones were investigated by X-ray diffraction, UV-visible spectra, infrared and ion trap mass spectra, and transmission electron microscopy. All as-prepared ZnO cones consisted of tiny single crystals with lengths of several micrometers. With prolonging of the reaction time from 1.5 h to 7 days, the twin-cone shape did not change at all, while the lattice parameters increased slightly and the emission peak of photoluminescence shifted from the green region to the near orange region. ZnO twin-cones are also explored as an additive to promote the thermal decomposition of ammonium perchlorate. The variations of photoluminescence spectra and catalytic roles in ammonium perchlorate decomposition were discussed in terms of the defect structure of ZnO twin-cones.