Study on the Catalytic Performance of Porous Cu/Cu2O Synthesized by One-Step Solvothermal Method for Thermal Decomposition of Ammonium Perchlorate

Porous Cu/Cu2O catalytic materials with a unique pore structure were successfully synthesized via a one-step solvothermal method using Cu-MOF-74 as the intermediate, followed by induced collapse and oxidation. The structural properties and catalytic performance of the as-prepared Cu/Cu2O materials in the thermal decomposition of ammonium perchlorate (AP) were systematically investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) surface area analysis, and thermogravimetry–differential scanning calorimetry (TG-DSC) combined with in situ thermogravimetry–mass spectrometry (TG-MS). The results show that the specific surface area of the Cu/Cu2O material is 46.6697 m2/g, and the average pore diameter is 9.4608 nm. Owing to the synergistic effect of Cu0/Cu+ dual sites on promoting electron transfer during AP thermal decomposition, the Cu/Cu2O catalyst exhibits excellent catalytic activity. Specifically, at a heating rate of 20 °C/min, the addition of 2 wt% Cu/Cu2O reduces the high-temperature decomposition temperature of AP from 473.1 °C to 321.1 °C (a decrease of 151.0 °C), lowers the thermal decomposition activation energy from 296.63 kJ/mol to 253.21 kJ/mol (a reduction of 43.42 kJ/mol), and increases the heat release by 617.8 J/g compared to pure AP. TG-MS analysis revealed that Cu/Cu2O accelerates the decomposition of AP by adsorbing and activating NH3 and HClO4 generated in the low-temperature decomposition stage, facilitating the formation of reactive intermediates such as ClOₓ and promoting the oxidation of nitrogen-containing species. This study demonstrates that the porous Cu/Cu2O material synthesized by the one-step solvothermal method is a promising catalyst for enhancing the thermal decomposition performance of AP in solid propellants.