Catalytic effect of Fe2O3, Mn2O3, and TiO2 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: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-015-5167-y

The kinetic and activation energies of thermal decomposition of KNO 3 as an oxidizer in pyrotechnic compositions were studied in the presence of Fe 2 O 3 , Mn 2 O 3 , and TiO 2 nanoparticles as catalysts, using thermogravimetric analysis under argon atmosphere at different heating rates (10, 15, and 20 K min −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 3 were calculated using non-isothermal isoconversional methods of KAS, OFW, and Friedman for different conversion fraction ( α ) 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 −1 , respectively, in the absence and presence of 5 mol% of Fe 2 O 3 , Mn 2 O 3 , and TiO 2 . The results indicated that while Fe 2 O 3 and Mn 2 O 3 nanoparticles have catalytic effects, TiO 2 nanoparticles show inhibitory effect on the thermal decomposition of KNO 3 .