Preparation of liquid metal–mediated aluminothermite and its catalytic effect on the thermal decomposition of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate

Aluminum readily undergoes oxidation under ambient conditions, forming a dense Al₂O₃ surface layer that retards the energy release by oxidation. To enhance the energy release of aluminum powder oxidation, this study focused on the preparation of liquid metal (LM) mediated thermite (LM-Al@oxide) by combining the aluminum powder with the nanosized metal oxides. The thermal properties of thermite and its catalytic effects on the thermal decomposition of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) were investigated by differential scanning calorimetry (DSC). Specifically, WO₃ and Fe₂O₃ significantly reduced the onset oxidation temperature of aluminum to near its melting point. Upon incorporating LM-Al@oxide composites, both the peak decomposition temperature and activation energy of TKX-50 decreased. Among them, LM-Al@Fe₂O₃ exhibited optimal catalytic activity for TKX-50 decomposition, reducing its peak decomposition temperature (T_p1) and mean apparent activation energy (E_a) by 24.5°C and 59.0 kJ·mol⁻¹, respectively, which could be attributed to electron acceptance from TKX-50 through Lewis acid sites in the oxides, thereby lowering the decomposition energy barrier.