Preparation of Cu-Containing Substances via an Ultrasonic-Assisted Solvothermal Approach and Their Catalytic Effects on the Thermal Decomposition of Ammonium Perchlorate

In this study, a one-pot, ultrasonic-assisted solvothermal method was successfully employed to prepare three copper-containing compounds: copper benzene-1,3,5-tricarboxylate (Cu₃(BTC)₂), copper powder, and copper-metalized activated carbon (Cu@AC). This method is efficient and safe and has potential for use in scalable production. The characteristics of the resulting products were analyzed using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), specific surface area measurement along with pore size distribution, and thermogravimetric analysis-differential scanning calorimetry (TG-DSC). Additionally, the catalytic effects of these products on the thermal decomposition of ammonium perchlorate (AP) were evaluated. All three substances were found to lower the thermal decomposition temperature of AP and enhance heat release. Cu₃(BTC)₂ demonstrated exceptional catalytic performance and compatibility with AP, as shown using the vacuum stability test (VST). The thermal analysis results indicated that the thermal decomposition temperature and apparent activation energy of AP decreased from ~442 °C to around 340 °C and from ~207 kJ mol^-1 to approximately 128 kJ mol^-1, respectively, when 3 wt% Cu₃(BTC)₂ was contained in AP. Moreover, the heat released via the exothermic decomposition of AP increased from 740 J g^-1 to1716 J g^-1. A possible reaction mechanism is proposed based on the evolved gas analysis (EGA) findings to explain the observed catalytic effects.