Development of bimetallic spinel catalysts for low-temperature decomposition of ammonium dinitramide monopropellants

Ammonium dinitramide (ADN) based liquid monopropellants have been identified as environmentally benign substitutes for hydrazine monopropellant. However, new catalysts are to be developed for making ADN monopropellants cold-start capable. In the present study, performance of Co and Ba doped CuCr2O4 nanocatalysts prepared by hydrothermal method was evaluated on the decomposition of aqueous ADN solution and ADN liquid monopropellant (LMP103X). The catalysts were characterized by PXRD (Powder X-ray Diffraction), FTIR (Fourier Transform Infrared spectroscopy), SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), EDS (Energy Dispersive X-ray Spectroscopy), and XPS (X-ray Photoelectron Spectroscopy). The nanosize was confirmed by SEM and TEM, while the nanoflake morphology was confirmed by the SEM analysis. Further, we obtained the elemental composition from the EDS analysis. We investigated the catalytic activity of the catalysts by thermogravimetric (TG) analysis and the developed catalysts lowered the decomposition temperature of ADN monopropellant by about 55 °C. The XPS analysis confirmed the presence of metal ions with different chemical states. Apparently, increase in the surface area of the catalysts and the mixed active sites as well as the development of oxygen vacancy on the catalyst surface introduced by metal doping are influencing the decomposition temperature of ADN samples. [Display omitted]