Three Novel Green Bismuth-Based Combustion Catalysts for Catalyzing the High-Energy Oxidizer RDX

Abstract

The combustion efficacy of propellants is crucial to the overall performance of rockets and missiles. Conventional propellant combustion catalysts suffer from toxicity and severe environmental pollution. To meet the demand for new green and non-toxic combustion catalysts, we synthesized three novel bismuth-based combustion catalysts, namely, [Bi2(DHBQDC) (OX)2(DMF)6] 1, [Bi(BPSA)(PHON)(Ph)]·3DMF 2, and [BiO(TFPHA)H₂O]·H₂O 3, in this study. The structures of the catalysts were determined by single-crystal X-ray diffraction (SCXRD), and their thermal stability was investigated. Results demonstrated that all three catalysts exhibited excellent thermal stability, with the decomposition temperature of their organic frameworks exceeding 200 °C. In addition, differential scanning calorimetry and thermogravimetry were employed to study the thermal decomposition performance of the catalyst–RDX mixed systems. The introduction of these catalysts promoted the decomposition of RDX, leading to a reduction in the decomposition temperature of the systems to varying degrees and a decrease in the activation energy of the reaction. A high-speed camera was used to study the flame combustion performance of the mixed catalyst systems with RDX+NC/NG, which further confirmed the catalytic performance of various catalysts.