Revealing the Effect of Copper Single-Atom Catalyst for Improved Energy Release of Ammonium Perchlorate.

Catalyzing ammonium perchlorate (AP) thermal decomposition is essential for improving the energy release of composite solid propellants. Single-atom catalysts (SACs) show great potential in AP catalysis, but systematic research on their regulation of AP decomposition and propellant combustion remains insufficient. Herein, four carbon black-supported transition metal single-atom catalysts (M-SACs, M = Fe, Co, Ni, Cu) were prepared via a coordination adsorption-pyrolysis strategy, and their atomic dispersion and coordination structure were systematically characterized. Thermal tests demonstrate that Cu-SAC delivers the best catalytic performance, reducing AP's high-temperature decomposition peak by 103.6°C, increasing heat release by 4.1 times, and lowering activation energy by 96.3 kJ/mol. Molecular dynamics simulations confirm that Cu-N active sites strongly adsorb key intermediates (NH3 and HClO) and weakly bind final products, providing a thermodynamic basis for its superior catalytic activity. In AP-based propellants, Cu-SAC increases burning rate by 25.6% and shortens ignition delay by 23.1%, while effectively suppressing molten aluminum agglomeration and reducing condensed combustion product size by 61%. This work establishes the multi-scale structure-activity relationship of Cu-N coordination, offering a new route for the design of high-performance propellant combustion catalysts.