Multi-Scale study on combustion acceleration and Self-Catalytic mechanisms of Nickel-Based energetic complex [Ni(N2H4)2](N3)2

Abstract

This study establishes a multi-scale system model to investigate the combustion acceleration characteristics and self-catalytic mechanisms of the nickel-based energetic complex [Ni(N₂H₄)₂](N₃)₂ (NHA). By examining the role of nickel and its oxides, particularly NiO, in accelerating the reaction, the research reveals that NHA experiences significant combustion acceleration due to the self-catalytic effects of the intermediate product NiO. In an air atmosphere, where oxygen promotes NiO formation, the activation energy initially fluctuates between 150 and 200 kJ·mol^–1, peaks at 317.04 kJ·mol^–1, and subsequently decreases. Under an argon atmosphere, the reaction of NHA is driven by its inherent properties and also releases a significant amount of heat. Thermal analysis shows that NHA decomposes in air through a two-step process, with major mass losses occurring at 216 °C and 265 °C, while in argon, decomposition occurs at lower temperatures (161 °C and 177 °C). X-ray diffraction (XRD) analysis identifies NiO as the primary combustion product in air and elemental Ni in argon, with peak combustion temperatures of 1460.3 °C in air and 949.9 °C in argon. These findings not only contribute to a comprehensive understanding of the combustion process of NHA but also provide an available research approach for studying the combustion behavior of initiatory explosives. This model can serve as a foundation for studying the combustion process of other primary explosives.