Construction of Fe Nanoparticles Interfacial Layer on Micron Al Surface: Boosting the Efficient Energy Release of High-Energy DAP-4 as a Gradient Catalyst.

The high-energy (Hdabco)[NH(ClO)] (DAP-4) with excellent energetic performance attracts wide attention from researchers. The investigation of its interaction with the Aluminum (Al) is of great importance. However, the higher ignition threshold of DAP-4 and the dense oxide layer (AlO) of Al severely limit the energy release efficiency of Al/DAP-4. In this study, a new idea to is first proposed to improve and adjust the thermal decomposition and combustion performance of Al/DAP-4 by constructing a highly dispersed iron (Fe) nanoparticle interfacial layer. It acts as a gradient catalyst to promote the thermal decomposition and combustion of DAP-4 and Al, and it also act as an oxygen transport channel to promote the contact and reaction of oxidizing gases with the internal reactive Al powder. It reduces the thermal decomposition temperature of Al@Fe-3/DAP-4 from 386.30 °C (Al/DAP-4) to 349.48 °C and leads to the vigorous combustion. Theoretical calculations show that Fe nanoparticle interfacial layer can facilitate the transport of oxygen through the established oxygen transport channels, and it can also significantly improve the energetic properties of Al@Fe-3/DAP-4 composites. In conclusion, the new approach is proposed to improve the performance of metal fuel/oxidizer composites by constructing interfacial layers, which is expected to promote their practical applications.