Аңдатпа
In this work, the catalytic effect of copper (I) iodide (CuI) synthesized by a mechanochemical method on the thermal decomposition of ammonium nitrate (NH4NO3) was studied. CuI was obtained by ball milling CuSO4·5H2O and KI at 300-400 rpm for 60-120 min. The results of X-ray phase analysis showed that CuI, with high phase purity, formed after 120 min of processing. The composite systems were prepared based on NH4NO3 by adding 1, 3, and 5 wt.% CuI. DSC analysis was carried out in the temperature range of 25-500 °C and at heating rates of 5-20 °C·min-1. While for pure ammonium nitrate the main thermal decomposition was observed at ~282 °C, the appearance of a pronounced exothermic peak at ~276 °C in the presence of CuI indicated an earlier reaction onset. In addition, it was found that the deepening of the endothermic effect at ~300 °C is associated with the intensive release of gaseous products. According to the results of kinetic analysis, the activation energy for pure NH4NO3 is in the range of 101.27-113.48 kJ·mol-1, while with the introduction of 5 wt.% CuI, this value decreases to 81.37-94.59 kJ·mol-1. In the second reaction stage, the activation energy decreases from 188.73 kJ·mol-1 to 159.71 kJ·mol-1. The observed decrease in activation energy is consistent with a mechanism reported in the literature involving Cu+/Cu2+ redox cycling and the possible formation of reactive radicals. The results show that CuI synthesized by the mechanochemical method significantly affects the thermal decomposition kinetics of ammonium nitrate, thereby decreasing the reaction energy barrier and increasing the system’s overall reactivity.