Initial Studies on Development of High-Performance Nano-structured Fe₂O₃ Catalysts for Solid Rocket Propellants

Space launch vehicles and strategic military vehicles commonly employ composite solid rocket propellants containing Fe₂O₃ as ballistic modifier. Nanoscale catalysts, including nanoscale Fe₂O₃, have been reported to exhibit superior activity in the thermal decomposition and combustion of composite rocket propellants. However, scalable methods to prepare such nano-structured catalysts with high performance as ballistic modifiers and systematic studies relating the synthesis parameters to the catalyst characteristics and consequently to the thermal and combustion properties of the composite propellant are scarce. In this paper, we report a novel and facile route to prepare nano-structured Fe₂O₃ with enhanced catalytic activity in the ballistic modification of ammonium perchlorate (AP)-based composite solid rocket propellant. A submerged spray precipitation method using air-assisted liquid-centered coaxial atomization has been developed to prepare these nano-structured Fe₂O₃ catalysts. The prepared Fe₂O₃ catalysts possess higher surface area and exhibit superior activity in the thermal sensitization of AP, leading to an 88% increase in the burning rate of AP-based composite solid rocket propellants, than the Fe₂O₃ catalyst prepared via traditional precipitation method. Merits of the developed preparatory route, influence of the atomization process on the nano-structure morphology and subsequent benefits of these nano-structured catalysts on the ballistic properties of AP-based propellants are demonstrated and discussed in this paper.