In situ formation of MxOy nano-catalysts (M = Mn, Fe) to diminish decomposition temperature and enhance heat liberation of ammonium perchlorate

Abstract

In order to reduce thermal decomposition temperature and enhance the decomposition enthalpy of ammonium perchlorate (AP) in solid fuels, metal spinel nano-catalysts (M3O4, M = Mn, Fe) were prepared simultaneous with AP thermal decomposition, using metal oxalates dihydrate (MC2O4·2H2O). The catalytic effect of nano-particles on AP thermal decomposition was studied by Differential Scanning Calorimetric (DSC) and Thermo Gravimetric (TG) analysis, which showed a decrease in the decomposition temperature from 428 °C to 311 °C for MnC2O4·2H2O in one step, whereas for FeC2O4·2H2O the thermal decomposition occurred in two steps at 294 °C and 393 °C respectively. The activation energy of pure AP, MnC2O4·2H2O@AP and FeC2O4·2H2O@AP were investigated under non-isothermal conditions. Two model-free methods such as Flynn–Wall–Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) were used to determine the Ea,α on a conversion fraction of α = 0.05 until 0.95. The results showed that both methods led to similar values of Ea,α, and they are in agreement with each other.