In situ synthesis NiO@TiO₂/MXene as a promoter for ammonium perchlorate based solid propellants

The carrier can widely affect or even dominate the catalytic activity and selectivity of nanoparticles for ammonium perchlorate (AP). In this work, a novel catalyst NiO@TiO₂/MXene (TN) nanocomposite was prepared by a simple hydrothermal method using two-dimensional MXene as the catalyst carrier. System characterization reveals that the utilization of MXene supports facilitates effective dispersion of NiO nanoparticles. TiO₂/MXene itself exhibits commendable catalytic activity and possesses a substantial specific surface area, thereby enabling regulation of the catalytic performance of NiO. TN surpasses both NiO and TiO₂/MXene in promoting the high temperature decomposition (HTD) of AP. By increasing the concentration of Ni²⁺ in the precursor, the loading capacity of NiO on the carrier is enhanced, consequently improving its catalytic capability towards AP. As the load of NiO increases, there is a decrease in high decomposition temperature (T_HTD) from 437.3 ℃ to 313.3 ℃, a reduction in activation energy (E_a) from 216.1kJ/mol to 114.6 kJ/mol, and an increase in heat release by 118 %. NH₃-TPD and O₂-TPD studies have shown that catalysts with strong surface adsorption capacity for NH₃ and O₂ exhibit excellent catalytic performance, leading to differences in their catalytic behavior. TG/FT-IR analysis further confirms that TN nanocomposites accelerate N₂O conversion to NO, which contributes to rapid AP decomposition.