Catalytic effect of Fe sub(2)O sub(3), Mn sub(2)O sub(3), and TiO sub(2) nanoparticles on thermal decomposition of potassium nitrate

• Published in: Journal of thermal analysis and calorimetry 2016-05, Vol.124 (2), p.1091-1098
• Main Authors: Ravanbod, Mohsen, Pouretedal, Hamid Reza
• Format: Article
• Language: English
• Subjects: Activation energy; Calorimetry; Catalysis; Catalysts; Nanoparticles; Oxidizers; Thermal decomposition; Titanium dioxide
• ISSN: 1388-6150; 1572-8943
• DOI: 10.1007/s10973-015-5167-y

The kinetic and activation energies of thermal decomposition of KNO sub(3) as an oxidizer in pyrotechnic compositions were studied in the presence of Fe sub(2)O sub(3), Mn sub(2)O sub(3), and TiO sub(2) nanoparticles as catalysts, using thermogravimetric analysis under argon atmosphere at different heating rates (10, 15, and 20 K min super(-1)). The prepared nanoparticles were characterized by XRD patterns, SEM images, and BET surface area analysis. For verification of data, the activation energies for thermal decomposition of KNO sub(3) were calculated using non-isothermal isoconversional methods of KAS, OFW, and Friedman for different conversion fraction ( alpha ) values in the range 0.1-0.9. The activation energies were 201.6-208.2, 170.0-177.9, 173.9-181.6, and 213.0-223.8 kJ mol super(-1), respectively, in the absence and presence of 5 mol% of Fe sub(2)O sub(3), Mn sub(2)O sub(3), and TiO sub(2). The results indicated that while Fe sub(2)O sub(3) and Mn sub(2)O sub(3) nanoparticles have catalytic effects, TiO sub(2) nanoparticles show inhibitory effect on the thermal decomposition of KNO sub(3).