Heterointerface-Driven Combustion Catalysis for Concentrated Heat Release of Ammonium Perchlorate Over Cu-BDC-NH2@TpPa.

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.