Heterointerface-Driven Combustion Catalysis for Concentrated Heat Release of Ammonium Perchlorate Over...

Combustion catalysts commonly improve the burning performance of composite solid propellants by lowering the thermal decomposition temperature of ammonium perchlorate (AP) and increasing AP heat release. However, heat release over a narrow temperature range is also critical for ignition response and regulation of the burning rate. To address this gap, we propose a concentrated heat release strategy for AP catalysis. This strategy is implemented using the Cu-BDC-NH₂@TpPa heterostructure (Cu-BDC-NH₂ = copper 2-aminoterephthalate; TpPa is formed by Tp, 1,3,5-triformylphloroglucinol, and Pa, p-phenylenediamine). The TpPa layer regulates contact between AP and Cu active sites. DSC results show that Cu-BDC-NH₂@TpPa-0.20 centers the main AP exothermic peak at 322°C and narrows the heat release range from 60°C for Cu-BDC-NH₂ to 12°C. Electrochemical measurements reveal lower electrochemical polarization and a more sensitive interfacial current response in the redox potential region. Condensed-phase in situ FTIR and TG-DSC-FTIR-MS analyses indicate that the TpPa interface modulates the local NH₄ ⁺/ClO₄ ^- vibrational environment and gaseous product evolution. DFT calculations suggest that the thermally evolved CuO/C composite interface favors the adsorption and transformation of NH₃-related intermediates while facilitating the desorption of NO and NO₂ products. This work provides an interface regulation strategy for combustion catalysis in energetic materials.