Electrochemical Synthesis of the Energetic Combustion Catalyst Co(BODN)·9H 2 O and Its Catalytic Effect on Ammonium Perchlorate Thermal Decomposition.

Safe, efficient, and green synthetic energetic combustion catalysts are of great importance for the application of ammonium perchlorate (AP) in solid propellants. In this study, a novel, simple, efficient, and green electrochemical method for synthesizing energetic combustion catalysts was designed and implemented to successfully synthesize Co(BODN)·9H 2 O (BODN = [2,2'-bi{1,3,4-oxadiazole}]-5,5'-dinitramide), a novel energetic combustion catalyst. The target products were characterized via single-crystal X-ray diffraction, powder X-ray diffraction, Fourier transform infrared spectroscopy, optical microscopy, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. Results reveal that Co(BODN)·9H 2 O crystallizes in the triclinic P 1̅ space group and has a density of 1.836 g cm -3 . The size of the Co(BODN)·9H 2 O crystal increases gradually with the increase in the reaction current and the prolongation of the reaction time, respectively. However, the change in reaction current and time does not affect the crystal form. In addition, with the increase in Co(BODN)·9H 2 O content, the peak temperature of high-temperature decomposition (HTD) and apparent activation energy of AP/Co(BODN)·9H 2 O gradually decrease, and the heat release during thermal decomposition gradually increases. The HTD peak temperature and apparent activation energy of AP/Co(BODN) 9H 2 O (10%) decrease by 97.9 °C and 94.2 kJ·mol -1 , respectively, compared with those of pure AP, and the heat release during thermal decomposition increases by 1613 J·g -1 . Furthermore, compared with those of the propellant containing pure AP, the burning rate and flame temperature of the propellant containing AP/Co(BODN)·9H 2 O (10%) increase by 8.15 mm s -1 and 458.44 °C, respectively. Real-time Fourier transform infrared spectroscopy reveals that CoO catalyzes the thermal decomposition of AP mainly by promoting electron transfer to accelerate the oxidation of NH 3 and the conversion of N 2 O to NO. In brief, this work provides new insights into synthesizing energetic combustion catalysts. Moreover, Co(BODN)·9H 2 O synthesized through the electrochemical method exhibits considerable application prospects for improving the thermal and energy performance of AP and the combustion performance of propellants.