Coordination-Site Engineering of Porphyrin COFs for Laser Ignition and Combustion Catalysis of Ammonium Perchlorate

Abstract

Rapid laser ignition and efficient subsequent combustion require distinct additive properties, yet integrating both into a single material remains challenging. Here, a Cu/Co-coordinated porphyrin-based covalent organic framework (Cu/Co-Tapp-Phen-COF) was constructed to combine photoresponse with AP decomposition catalysis. The framework was synthesized from premetalated Cu-Tapp, followed by postsynthetic Co coordination at the Phen sites. Metal incorporation modifies the framework’s electronic environment while preserving its ordered structure. Cu/Co-Tapp-Phen-COF exhibits enhanced O2•– generation under 808 nm irradiation and promotes AP thermal decomposition, lowering its high-temperature decomposition peak from 431.1 to 350.6 °C and the apparent activation energy from 224.14 to 144.50 kJ mol–1, accompanied by earlier gas evolution. AP/Cu/Co-Tapp-Phen-COF achieves an ignition delay of approximately 3.5 ms and a combustion duration of 2.08 ± 0.05 s. Mechanistic analysis indicates that photoinduced O2•– contributes to laser ignition, while metal-coordinated sites promote AP thermal decomposition and subsequent combustion. These findings demonstrate that coordination-site engineering is an effective strategy for integrating photoresponse and combustion catalysis within a single COF.