Energetic Metal–Organic Frameworks (EMOFs) as Additives for Composite Solid Propellants: Unlocking the Thermal Catalytic Performance for Potassium Perchlorate

Abstract

Potassium perchlorate (KP) is a key oxidizer in solid propellants. However, the high decomposition temperature (HTD) and activation energy (Ea) of KP hinder its application. Traditional transition metal oxide catalysts for KP can partially reduce HTD, but they are still plagued by low heat release (Q) and high Ea. We first propose a strategy to design energetic metal–organic frameworks (EMOFs), [M(DCA)2(1-VIM)2]n (M = Mn, Zn; denoted as 1 and 2), incorporating high-energy dicyanamide (DCA–) anions and 1-ethenylimidazole (1-VIM) ligands, as efficient catalysts for KP. At a loading of 5 wt %, compound 1 reduced the HTD of KP from 606.4 to 424.1 °C, increased the Q from 349.9 to 1071.0 J g–1 and lowered the Ea from 191.1 to 125.9 kJ mol–1. Meanwhile, a loading of 5 wt % 2 afforded the HTD of 465.2 °C, Q of 984.1 J g–1, and Ea of 165.6 kJ mol–1, indicating superior catalytic performance of 1. Experimental evidence demonstrates that 1 achieves superior performance by synchronizing fuel release with O• generation from KP, enabling a two-stage combustion feedback loop that lowers the HTD and enhances Q. These findings guide future design of solid propellant catalysts.