Thermal decomposition of ammonium perchlorate over perovskite catalysts: Catalytic decomposition behavior, mechanism and application

Perovskite-based catalysts show a versatile catalytic ability for redox reactions, but are seldom applied for ammonium perchlorate (AP) decomposition. Their catalytic mechanism on AP decomposition still remains unknown. In this study, four different perovskites, namely LaCoO₃, La₂CuO₄, LaMnO₃ and LaNiO₃, were prepared by co-precipitation method and then applied to catalyze the AP decomposition. LaCoO₃ exhibited the best catalytic performance among all the perovskites used, in which the decomposition temperature of AP was lowered to 301.1 °C (114.9 °C lower than pure AP) and the heat release was increased from 768 to 1428 J g⁻¹. A series of characterization on these four perovskites, such as XRD, SEM, NH₃-TPD, O₂-TPD and XPS, revealed that stronger adsorption abilities of catalysts for NH₃ and O₂ on the surface led to better catalytic performance, thus explaining their differences in the catalytic performance. Online TG/FT-IR further revealed that perovskite catalysts could significantly inhibit the conversion of N₂O to NO, which was benefit to the enhancement of heat release. Finally, the perovskite catalysts were mixed with HTPB-based propellant to test their real application, and the results showed that perovskite containing HTPB-based propellant exhibited an increased burning rate and combustion heat, thus demonstrating their potential application in solid propellant.