Study on the thermal decomposition behavior of ammonium perchlorate catalyzed by Zn–Co cooperation in MOF

Abstract

The combustion performance of solid propellants plays a decisive role in the overall application of rockets. Changing the decomposition behavior of ammonium perchlorate (AP) by adding a catalyst is an effective strategy to control the combustion of solid propellants. Among them, the synergistic catalysis of AP thermal decomposition through different catalytic paths is clearly more efficient. Despite the effectiveness of catalysts, the catalytic mechanism is not clear. In this study, a bimetallic ZnCo–ZIF was used as a catalyst for the thermal decomposition of AP, and the thermal decomposition behavior of AP, actual catalytic component, and the synergistic mechanism of two metals were analyzed. The results showed that ZnCo–ZIF had the best catalytic effect for AP thermal decomposition, high temperature decomposition of AP reached 317.6 °C, and heat release reached 1945 J g⁻¹. The in situ monitoring of gas products via the TG-IR test showed that ZnCo–ZIF could decompose in advance in the presence of AP, while Co₃O₄/ZnO with good dispersion actually played a catalytic role, and the two metal oxides accelerate the decomposition of AP and contribute more heat release through a synergistic effect in the catalytic process. The synergistic catalytic process can be explained by the mechanism of reactive oxygen oxidation and lattice oxidation, and Zn improves the oxidation degree of N and generates nitrogen oxides (N₂O, NO, and NO₂) by releasing lattice oxygen, while Co weakens the N–H bond and accelerates the oxidation of NH₃. These two catalytic processes occur together, reducing the temperature of the AP decomposition peak and increasing heat release. This interesting synergy phenomenon provides experience for exploring synergies between two or more metals.