Thermal decomposition catalytic properties of ammonium perchlorate with three new energetic complexes on the basis of metal centre regulation

Abstract

Due to the diverse structural configurations and exceptional thermal stability, energetic complexes have been extensively utilized as catalysts for the thermal decomposition of ammonium perchlorate (AP). Nevertheless, enhancing the catalytic activity of these energetic complexes remains a significant challenge. In this study, three nitrogen-rich heterocyclic complexes, M(Hapza)₂(H₂O)₄ (M = Co, Zn, and Cd), were successfully synthesized by the hydrothermal method using 3-aminopyrazole-4-carboxylic acid (H₂apza) as an energetic ligand. Single-crystal X-ray diffraction analysis revealed that the three complexes are single-nucleated and isomorphic, forming thermally stable three-dimensional supramolecular structures through extensive hydrogen bonding networks. The incorporation of these complexes significantly advanced the high decomposition peak of AP by 26.9–51.4 °C and reduced the activation energy (E_a) by 41.19–52.99 kJ mol⁻¹, demonstrating their remarkable catalytic effect on AP. The detonation properties of the complexes were evaluated using the Kamlet-Jacobs equation, revealing that these complexes possess higher detonation velocities (8.9–9.4 km s⁻¹) and detonation pressures (36.1–42.4 GPa) compared to traditional energetic materials. Further investigation into the possible catalytic mechanism suggested that metal oxides, generated from the decomposition of metal complexes, may facilitate charge transfer and enhance the desorption of NH₃ during the high-temperature decomposition stage of AP. This study highlights the importance of experimental and theoretical analysis, providing a fresh perspective for the development of complexes in the field of energetic materials.