Novel energetic coordination compound [Cu(AT)₄]Cl₂ for catalytic thermal decomposition of ammonium perchlorate

The lower high-temperature decomposition (HTD) temperature of ammonium perchlorate (AP) and more heat release of composite solid propellants (CSPs) put forward higher requirements on thermal catalysts. Herein, a new anhydrous energetic coordination compound [Cu(AT)₄]Cl₂ was well-designed and synthesized by coordination reaction of copper(II) and 5-amino-1H-tetrazole (AT), in which copper(II) catalytic active center has catalytic effect on reducing the HTD temperature of AP, and energetic AT can increase heat release. The structure of [Cu(AT)₄]Cl₂ was well determined by single crystal X-ray diffraction. The excellent thermal stability of [Cu(AT)₄]Cl₂ was verified by the results of thermogravimetric analysis and non-isothermal kinetics method. The catalytic activity of [Cu(AT)₄]Cl₂ for AP thermal decomposition was studied by the differential thermal analytical. The results indicated that the HTD peak of AP was significantly decreased by 60 ​K–495 ​K, and the activation energy of AP decreased by 57.5 ​kJ ​mol⁻¹ to 163.37 ​kJ ​mol⁻¹. The results of TGA-FTIR shows that the [Cu(AT)₄]Cl₂ will decompose and produce HCN gas before catalyzing AP, then the thermal decomposition products participated in the thermal decomposition of AP as an effective component of catalysis. The mechanical sensitivities and energetic characteristics of [Cu(AT)₄]Cl₂ was also studied by mechanical sensitometer, Calvet-type differential thermal conductivity calorimeter, and Kamlet-Jacbos equations. The results indicated that [Cu(AT)₄]Cl₂ has lower sensitivity than Trinitrotoluene and brilliant energetic characteristics. The [Cu(AT)₄]Cl₂ is expected to be one candidate additive in CSPs for catalytic thermal decomposition of AP.