Thermal Decomposition Pathways in Perovskite Energetic Material DAP-7: Mechanisms and Metal Oxide Mediation

Perovskite energetic material [C₆H₁₄N₂)(NH₃NH₂)(ClO₄)₃] (DAP-7) exhibits an exceptional detonation performance and thermal stability. This study elucidates its thermal decomposition behavior and added metal oxide mediation. Monoclinic DAP-7 crystals underwent a phase transition at 112 °C, followed by a two-stage exothermic decomposition (peak at 383 °C). Kinetic analysis via Kissinger, combined, and Friedman methods yielded activation energies of 238.19 kJ/mol (initial step) and 188.99 kJ/mol (secondary step), governed by A2 mechanisms (random two-dimensional nucleation and nucleus growth model). Gas-phase products (H₂O, CO, HCl, NH₃, etc.) were identified via synchronous FTIR-MS. Incorporation of Fe₂O₃ consolidated the decomposition pathway into a single peak (ΔT = -40 °C), reducing energy activation to 193.80 kJ/mol, while CuO accelerated early-stage reactions (peak shift +140 °C) via reactive intermediate enrichment. Combustion tests revealed that DAP-7/CuO achieved a remarkable linear burning rate of 32 mm/s, outperforming pure DAP-7 (7.1 mm/s). Theoretical calculations and experimental validation demonstrate that DAP-7's hexagonal prism morphology and crystal lattice stability, with dominant H···O/H···H interactions, stabilize the perovskite framework, and added metal oxides strategically modulate decomposition pathways, which are beneficial for enhancing energy release efficiency and combustion dynamics. These findings position DAP-7 as a promising candidate for high-energy propellant applications, with catalytic mediation engineering offering a viable pathway to tailor its reactivity performance.