Kinetics Model Reconstruction for Multistep Overlapping Thermal Decomposition of Ammonium Perchlorate with and without the Copper Oxide Compound Catalyst

The effects of copper oxide compound catalyst (Cu-O) on various stages of ammonium perchlorate (AP) thermal decomposition were investigated by TG. The results show that the thermal decomposition rate at the low-temperature section increases and the temperature at the maximum thermal decomposition rate (T_m) appears at 571 K when the Cu-O catalyst was added. The T_m at the high-temperature section is reduced from 660 K to 606 K. The thermal decomposition activation energy (E_a) of the whole process shows that the E_a of pure AP is significantly higher than that of AP+Cu-O when α > 0.25. According to the Gaussian peak-fit, the thermal decomposition of pure AP and AP+Cu-O can be divided into four stages. The E_a of each stage shows that the Cu-O catalyst has a significant catalytic effect on the first three stages of AP thermal decomposition, but has almost no catalytic effect on the fourth stage. According to the Coats-Redfern (CR) and masterplot method, the four stages of pure AP and AP+Cu-O are consistent with the n-order reaction F model and the Avrami-Eroféev (AE) model. Finally, the mechanism function reconstruction of four stages for pure AP and AP+Cu-O is completed by Arrhenius equation and kinetics compensation effect.