Effects of doping on the thermal decomposition of potassium perchlorate
TL;DR: In this paper, the effects of impurities and additives on the thermal decomposition of potassium perchlorate have been investigated by thermoanalysis, and the results indicate that the predominant effect of the impurities in altering the thermal stability of the potassium per chlorate is the formation of molten phases.
About: This article is published in Journal of Inorganic and Nuclear Chemistry.The article was published on 1965-07-01. It has received 6 citations till now. The article focuses on the topics: Thermal decomposition & Potassium perchlorate.
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TL;DR: In this article, the catalytic decomposition of KClO4 by Fe2O3, obtained by calcination of Fe(II) salts at different temperatures, was investigated by DTA, TG, X-ray and IR.
Abstract: The catalytic decomposition of KClO4 by Fe2O3, obtained by calcination of Fe(II) salts at different temperatures, was investigated by DTA, TG, X-ray and IR. A sample without catalyst was found to begin fusion and decomposition simultaneously, and to form an intermediate, KClO3. Addition of catalysts resulted in solid-phase decomposition before fusion of KClO4, and in a small amount of KClO3. The difference in catalytic effect observed for different catalysts was less in the molten-phase decomposition than in the solid phase. The initial decomposition temperature (T
i) increased with the temperature of preparation of the catalyst and showed a definitive relationship with the crystallite size of the catalyst. The change ofT
i is discussed on the basis of then-type semiconductive properties of the catalyst.
32 citations
TL;DR: In this article, 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.
Abstract: 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.
31 citations
TL;DR: In this paper, a study of the thermal decomposition of intimate mixtures of different molar ratios of KClO4 and chromium(III) oxide was conducted employing thermogravimetry, differential thermal analysis, chemical analysis, infrared spectroscopy and X-ray diffraction analysis.
22 citations
TL;DR: In this article, the catalytic effect of a mixed oxides system, consisting of MnO2-CuO in different atomic ratios (Cu/(Cu+Mn) = x, where x = 0-1), on the non-isothermal decomposition of KClO4 has been studied according to an electron transfer mechanism.
16 citations
TL;DR: In this article, the effect of catalyst properties such as surface area, non-stoichiometry and electrical characteristics on the thermal decomposition of KClO4 was investigated using thermogravimetric analysis.
13 citations
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TL;DR: In this article, a detailed differential thermal analysis curve for the decomposition of potassium perchlorate is presented for the first time, which reveals two exothermal processes: one during decomposition prior to the precipitation of potassium chloride and the other which occurs simultaneously with the precipitation.
Abstract: Gordon and Campbell published a paper1 in which the differential thermal analysis of potassium perchlorate is illustrated from the point of view of the characterization of this compound rather than the details of its decomposition. In this work, where the differential thermal analysis was carried out in a test-tube in an open furnace, a large endotherm following the initial exotherm after fusion was observed. Later, Markowitz and Boryta2 became interested in the details of decomposition as revealed by differential thermal analysis and pointed out that this endotherm is due to the molten sample rising up the sides of the tube resulting in separation of the sample from the thermocouple. This gives rise to an apparent endotherm at that point. These authors attempted to overcome the thermal effects which accompany the separation of the sample from the thermocouple by carrying out the thermal analysis in a closed furnace system. Although the endotherm in question is not observed under these conditions, the details of the decomposition are missed, undoubtedly due to the large mass of sample used in these experiments and because of poor heat transfer conditions in the closed furnace system. The approach in conducting the differential thermal analysis experiments in the present work is to adjust the sample mass and dimensions of the sample container so that the decomposing gases will not force the reacting mass up the tube. This results in intimate contact of the sample with the thermocouple throughout the entire reaction, which is after all the best condition for the differential thermal analysis experiment. It was found that when 500 mg and less of potassium perchlorate are contained in test-tubes with a ninside diameter of 16 mm separation of the sample from the thermocouple does not occur. These experiments show that it is possible to obtain detailed differential thermal analysis curves for decomposition reactions which are accompanied by violent foaming and bubbling by adjusting sample weight and geometric experimental parameters. In this work the detailed differential thermal analysis curve for the decomposition of potassium perchlorate is presented for the first time, which reveals two exothermal processes: one during decomposition prior to the precipitation of potassium chloride and the other which occurs simultaneously with the precipitation of potassium chloride. This was determined in differential thermal analysis experiments carried out in a metal block previously described1 where provisions were made for observing the sample as it was heated.
10 citations
TL;DR: In this paper, it was shown that perchlorate in fused sodiund hydroxide at temperatures from 360 to 420 deg can decompose to chloride in two consecutive first-order reactions.
Abstract: Sodium perchlorate in fused sodiund hydroxide at temperatures from 360 to 420 deg is found to decompose to chloride in two consecutive first-order reactions. Rate constants for conversion of perchlorate to chlorate and from chlorate to chlordde were evaluated, the first step being the faster. Respective activation energies of 47.3 and 53.2 kcal mole-1 were calculated. Decomposition rates are much greater in fused sodium hydroxide than in fused sodium nitrate. It is suggested that the decomposition is promoted by hydroxyl ion through the formation of a peroxide intermediate.
4 citations