Hypergolic Propellants Based on Hydrogen Peroxide Oxidizer

This chapter provides a comprehensive review of recent advancements in hypergolic bipropellants utilizing high-concentration hydrogen peroxide (H₂O) as a green oxidizer. It systematically surveys a wide array of fuel classes, including composite solid fuels based on a variety of borohydrides, energetic ionic liquids (EILs), advanced solid fuels leveraging transition metal complexes, and innovative fuels derived from renewable biomass. The review also covers gelled propellants, which offer enhanced safety. The highlighted key developments include the engineering of catalytic promoters to achieve sub-10-ms ignition delay times (IDTs) and the discovery of promoter-free hypergolicity in thiocyanate-based EILs. The chapter concludes that despite slightly lower specific impulse in comparison to N-based legacy toxic systems, the combination of reduced toxicity, high density, operational safety, and lower cost makes H₂O-based hypergolic propellants a highly promising technology for enabling more sustainable and accessible space exploration.