Thermal Decomposition CharacteristicS of Ammonium Nitrate(v) in the Presence of Mn2O3/Graphene Oxides

Abstract

Nano-composites (Mn2O3, Mn2O3/graphene oxides (GO)) were prepared by a new method. The nano-composites were characterized by XRD and HRTEM. The catalytic performance of the nano-composites on the thermal decomposition of ammonium nitrate(V) (AN) was investigated by TG-DSC and TG-MS. The reaction of AN with the nano-composites in the condensed phase was investigated by RSFTIR. The results of TG-DSC experiments indicated that the nano-composites significantly catalyze the thermal decomposition of AN, especial Mn2O3/GO. The exothermic reaction of AN with Mn2O3/GO commenced at about 185 °C. Based on the TG-MS results, it was ascribed to N2O formation. In the RSFTIR experiments, the dissociation reaction and ionization reaction of AN were both detected. NOx formation at low temperature was also found. NH2 was directly oxidized by HNO3/NO3− at low temperature. The interaction between Mn2O3 and NH3 was detected according to DRIFT experiments. At elevated temperature, the functional groups of GO are destroyed, which had an influence on the interaction between Mn2O3 and GO. A probable mechanism for the exothermic reaction and then its disappearance is proposed. HNO3 gas was absorbed on the surface of solid AN, which can markedly catalyze the thermal decomposition of AN. Perhaps the HNO3 plays a key role in the exothermic reaction and then the reaction of AN disappears at very low temperatures.