Catalytic decomposition mechanism of aqueous ammonium dinitramide solution elucidated by thermal and spectroscopic methods

Abstract

Ammonium dinitramide (ADN) is a green, energetic and oxygen rich molecule, developed to replace the commonly used oxidizer ammonium perchlorate (AP). On combustion ADN produces relatively environmental-friendly species such as H2O, NO2, N2O, NO etc., compared to HCl, Cl2, CO2, CO, H2, H2O, N2 and highly reactive chlorine species produced by AP combustion. The ADN synthesized in our laboratory was dissolved in deionized water to prepare aqueous ADN solutions (aq. ADN). The thermal decomposition of solid ADN and aq. ADN were studied and the products of decomposition are identified using a thermogravimetric analyser hyphenated with a FTIR instrument. Nano CuO catalyst was synthesized and aq. ADN was decomposed over the nanocatalyst and the catalytic decomposition mechanism is also elucidated. The study shows that, the condensed phase decomposition of aq. ADN is influenced by the CuO nanocatalyst leading to the generation of higher concentrations of NO2, which autocatalyzes the remaining ADN decomposition.