Effects of high‐energy multicore ferrocene‐based catalysts on the thermal decomposition of ammonium perchlorate

Abstract

AbstractThree high‐energy multicore ferrocene‐based catalysts containing energy bonds (C═N, N–N) (EMFcs), EMFcs‐1, EMFcs‐2, and EMFcs‐3, were designed and synthesized to reduce the high temperature decomposition (HTD) temperature and increase the heat release of ammonium perchlorate (AP) as well as improve anti‐migration performance for the development of composite solid propellants. The theoretical calculation of the highest occupied molecular orbital (EHOMO), the lowest unoccupied molecular orbital (ELUMO), and the electrostatic potential (ESP) were performed to explore the electronic structure of EMFcs (1–3) and predict their catalytic performance on AP. The chemical structures were confirmed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), ultraviolet (UV), and elemental analysis, and the oxidation ability was evaluated by cyclic voltammetry (CV). The catalytic performance of obtained catalysts was verified by differential scanning calorimetry‐thermogravimetry (DSC‐TG), and the results showed that the designed catalysts possessed much higher heat release and catalytic activity on AP thermal decomposition than that of widely used catalyst of catocene in the solid propellant, and EMFcs‐2 with three ferrocene units showed the best catalytic performance due to the highest Fe content in one molecule of EMFcs‐2. The composite of AP containing 5 wt% of EMFcs‐2 can reduce the HTD temperature of AP from 394°C to 285°C and low the activation energy from 185.81 to 103.18 kJ·mol−1 with heat release increasing from 630.60 to 1841.50 J·g−1. Furthermore, the thermal decomposition gaseous products of AP under the catalysis of EMFcs were confirmed by TG‐FTIR to explore the catalytic decomposition mechanism.