New Insights into the Catalytic Decomposition of Ammonium Perchlorate and Decomposition Mechanism by Nano-CuO Dispersed in Graphite-Carbon Nitride Nanosheet Composites

Graphical In this study, n-CuO-X/g-C 3 N 4 composites have been synthesized and were applied for catalyzing AP thermal decomposition. The generated n-CuO/g-C 3 N 4 composites were the excellent catalyst for AP-based composite solid propellants to improve their decomposition efficiency and energy output. The thermal decomposition mechanism of AP was investigated and n-CuO-X/g-C 3 N 4 composites could effectively change the thermal decomposition path of AP and significantly inhibited the conversion of N 2 O to NO during decomposition, thus increasing the apparent heat release of AP decomposition. Enhancing the exothermic decomposition of ammonium perchlorate (AP) is of great significance to obtain solid propellants with excellent combustion performance. Herein, we prepared a series of composites for catalyzing the exothermic decomposition of AP by a facile method with different masses of nano copper oxide (n-CuO) dispersed in graphene-nitride carbon (g-C 3 N 4 ) nanosheets. Among them, n-CuO-8/g-C 3 N 4 showed the best catalytic activity, which reduced the high-temperature decomposition (HTD) value by 95.0 °C, and increased the total heat release by 505 J ⋅ g −1 . The n-CuO-12/g-C 3 N 4 also reduced the activation energy ( E a ) of the HTD stage by 47.34 kJ ⋅ mol −1 . The catalytic mechanism study suggested that the n-CuO-X/g-C 3 N 4 composites promoted the transition of electrons (e − ) and holes (h + ) from ClO 4 − to NH 4 + and inhibited the recombination of e − and h + , which further enhanced the exothermic decomposition of AP. During decomposition, the transformation of N 2 O to NO was significantly inhibited by the n-CuO-X/g-C 3 N 4 composites, thus increasing the integral heat release as evidenced by Real-time thermogravimetry/Fourier transform infrared spectroscopy. This study illustrated that n-CuO-X/g-C 3 N 4 composites are catalysts for the efficient decomposition of AP, which further enhance the energy performance of solid propellants.