I. Pelly

Bio: I. Pelly is an academic researcher from Hebrew University of Jerusalem. The author has contributed to research in topics: Thermal decomposition & Perchlorate. The author has an hindex of 2, co-authored 4 publications receiving 13 citations.

A Study on the Mechanism of the Thermal Decomposition of Ammonium Perchlorate

Abstract: The thermal decomposition of ammonium perchlorate in the presence of potassium chloride and chromium (III) oxide was investigated using K36 Cl and51 Cr2 O3 to elucidate the reaction mechanism. Two simultaneous routes are suggested for the decomposition. It was found that double decomposition in vacuo between potassium chloride and ammonium perchlorate does not result in the formation of potassium perchlorate. Chromium (III) oxide was not oxidized by ammonium perchlorate, but oxidation to the hexavalent state took place when potassium chloride was present.

On the reaction between molten lithium perchlorate and chromium(III) oxide

Abstract: The reaction at 300°C between molten lithium perchlorate and chromium(III) oxide gave lithium dichromate. When lithium perchlorate and chromium(III) oxide were in the formula weight ratio of 2:1 respectively, the chromium was oxidized completely into the hexavalent oxidation state, and only a negligible chloride percentage of 0·1 remained in the resulting lithium dichromate. Different formula weight ratios were taken for the reaction at 300°C. In the runs where the formula weight ratios of the perchlorate and oxide were lower than 2:1, the amount of chromium oxidized was higher than expected by the proposed route, and an explanation is given. Reactions with 51Cr2O3 showed that a very small amount of chromium volatilized. Results obtained from experiments both in vacuum and air were in very good agreement. A reaction mechanism is proposed.

Thermal decomposition of nitrosyl perchlorate and nitryl perchlorate—I: Mechanism of decomposition

Abstract: The thermal decomposition of NOClO4 (powder, or fragments of pressed pellets) and of NO2ClO4 (granules) has been studied gasometrically and by X-ray diffraction. During the decomposition of NOClO4, NO2ClO4 is formed as an intermediate. The following mechanism is suggested for the decomposition of NOClO4: NOCl 4 → ClO 3 + NO 2 , 3 NOClO 4 + ClO3 → 1 2 +3 NO 2 ClO 4 , 3 NO 2 ClO 4 →3 ClO 2 +3 NO 2 +3 o 2 . NO2ClO4 is partly reduced to NOClO4. Independently of the initial sample, the reaction mixture will contain both perchlorates.

Thermal decomposition of nitrosyl and nitryl perchlorate—II

Abstract: The decomposition of mixtures of metal oxides with NOClO4 or NO2ClO4 was studied by gasometry, thermogravimetry, D.T.A. and i.r. absorption. It is shown that NOClO4 is first converted to NO2ClO4, which reacts with some of the oxides to form the corresponding metal perchlorate. The weight loss indicated by the thermogravimetric curves is in quantitative accord with this description and the mechanism previously proposed for the decomposition of NOClO4.

Thermal decomposition of ammonium perchlorate

Abstract: 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.

Effect of Transition Metal Oxides on Decomposition and Deflagration of Composite Solid Propellant Systems: A Survey

Abstract: Introduction T metal oxides (TMO) like Fe2O3, CuO, MnO2, CuCr2O4, etc., form a very popular group of catalysts for burning rate modification of composite solid propellants. Although it is well known that these oxides affect the decomposition characteristics of polymers and oxidizers like ammonium perchlorate (AP)' and potassium perchlorate, (KP) the exact mechanism of the effect on solid propellants is by no means clear even today. Much fragmentary literature is available on the effect of these oxides on propellant burning and decomposition, oxidizer burning and decomposition, and sandwich and condensed mixture combustion. It is the purpose of this review to bring the material together so that a comprehensive picture can be drawn of the mechanism of the action of these catalysts. It may be mentioned here that these oxides also catalyze hydrocarbon oxidation reactions by inducing free radical decomposition of hydroperoxides (formed by the contact of oxidizer and hydrocarbon).

Thermal decomposition of ammonium perchlorate in the presence of Al(OH)(3)·Cr(OH)(3) nanoparticles.

Abstract: An Al(OH)(3)center dot Cr(OH)(3) nanoparticle preparation procedure and its catalytic effect and mechanism on thermal decomposition of ammonium perchlorate (AP) were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TG-DSC), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis and mass spectroscopy (TG-MS) In the preparation procedure, TEM, SAED, and FT-IR showed that the Al(OH)(3)center dot Cr(OH)(3) particles were amorphous particles with dimensions in the nanometer size regime containing a large amount of surface hydroxyl under the controllable preparation conditions When the Al(OH)(3)center dot Cr(OH)(3) nanoparticles were used as additives for the thermal decomposition of AP, the TG-DSC results showed that the addition of Al(OH)(3)center dot Cr(OH)(3) nanoparticles to AP remarkably decreased the onset temperature of AP decomposition from approximately 450 degrees C to 245 degrees C The FT-IR, RS and XPS results confirmed that the surface hydroxyl content of the Al(OH)(3)center dot Cr(OH)(3) nanoparticles decreased from 6794% to 6365%, and Al(OH)(3)center dot Cr(OH)(3) nanoparticles were limitedly transformed from amorphous to crystalline after used as additives for the thermal decomposition of AP Such behavior of Al(OH)(3)center dot Cr(OH)(3) nanoparticles promoted the oxidation of NH3 of AP to decompose to N2O first, as indicated by the TG-MS results, accelerating the AP thermal decomposition (C) 2014 Elsevier BV All rights reserved

Facile preparation of Cr2O3 nanoparticles and their use as an active catalyst on the thermal decomposition of ammonium perchlorate

Abstract: Cr2O3 nanoparticles were prepared by repeated wet mechanical milling technique. Three drying methods, oven drying, vacuum drying, and vacuum freeze-drying were comparatively used to dry Cr2O3 nanop...

Evaluation of kinetic parameters from a single TG curve based on the similarity theory and process symmetry

Abstract: The equation for calculation of the activation energy of the diffusion of the evolved products through the matrix (E) from a single TG curve were proposed by solving Fick's laws. The solution is based on the similarly theory by utilizing a Fourier number. The proposed method was examined by using mass loss data for the dehydroxylation of some micas with and without FeO (muscovite and its varieties and lepidolite) as determined from their TG curves. TheE values for the first stage of the dehydroxylation of these micas areE 1,=85±10 kJ mol−1; for the final stageE 2=380±40 kJ mol−1 and for the mass loss connected with fluorineE F=85±10 kJ mol−1.