Catalytic Decomposition of Energetic Liquid Solution Over Various Types of Hexaaluminate Catalysts.

A hexaaluminate support was prepared by a co-precipitation method, and a metal (Cu, Pt, or Ir) was impregnated on the support to prepare a powdered catalyst. After that, organic and inorganic binders were added to the powdery catalyst and then pellets were formed. The so-formed catalysts were heat-treated at 1200°C, and their physicochemical properties were analyzed by N₂-adsorption, X-ray diffraction (XRD), X-ray fluorenscence (XRF), and scanning electron microscopy (SEM). The decomposition activity of the catalysts on an ammonium dinitramide (ADN)-based liquid propellant was evaluated repeatedly, and the effects of catalyst composition and morphology on low temperature decomposition activity and durability were investigated. It was confirmed that the Cu-hexa-pellet, Pt-hexa-pellet, and Ir-hexa-pellet catalysts could be recovered and reused as a catalyst for decomposition of an ADN-based liquid monopropellant. The initial activity and the thermal stability of the Cu-hexa-pellet catalyst for the decomposition of ADN-based liquid monopropellants were better than for the other catalysts. The better activity of the Cu-hexa-pellet catalyst seems to be because the dispersion of the copper was higher than the metal dispersion in the other two catalysts.