Metal-organic Hybrid Hypergolic Materials

Hypergolic materials, which can ignite spontaneously upon contact with oxidizers and self-sustain the reaction under ambient conditions, are a prominent component of bipropellant systems. However, the traditional hydrazine-based hypergolic fuels suffer from toxicity and corrosive issues. In pursuit of rational design and development of high-performance hypergolic fuels, metal-organic hybrid materials are gradually stepping into researchers’ views by virtue of their high density and stability compared to hydrazine-based materials. The diverse compositions and tailorable structures of metal species and organic ligands provide infinite possibilities in this field. In this chapter, a comprehensive overview of metal-organic hypergolic fuels from 0D metal complex/cluster to 3D metal-organic frameworks (MOFs) is presented, highlighting their potential in hybrid bipropellant propulsion systems. Essential properties related to hypergolicity were discussed to analyze the effects of the metal cores and organic ligands on the combustion reaction. Our conclusion involves sharing our thoughts on the opportunities and challenges of designing next-generation hypergolic fuels and promoters.