Effect of metal-carbonitride layered composites with different Ni/Fe molar ratios on the thermal decomposition and combustion performance of energetic components

The development of highly efficient catalysts for regulating thermal decomposition and combustion behavior of energetic components is of great significance. This study successfully designed, synthesized and characterized a series of nickel-iron layered double oxide doped graphitic carbon nitride (NFL@CN-X, X = 1, 3, 5) composite combustion catalysts with varying Ni/Fe molar ratios through electrostatic self-assembly followed by thermal treatment. These catalysts exhibit well-developed porous structures and highly active metal centers. The effects of these catalysts on the thermal decomposition behavior of Ammonium perchlorate (AP), Cyclotrimethylene trinitramine (RDX), Cyclotetramethylene tetranitramine (HMX) and Hexanitrohexaazaisowurtzitane (CL-20) were systematically investigated using differential scanning calorimetry (DSC) and thermogravimetric (TG) analyses, and relevant kinetic and thermodynamic parameters were calculated. In addition, the optimal catalyst was employed for ignition experiments, and high-speed camera technology was employed to evaluate their impact on the combustion performance of various energetic composite systems. Furthermore, a potential catalytic mechanism was proposed using HMX as a representative energetic compound, based on thermogravimetric-mass spectrometry (TG-MS) analysis. The DSC and TG results revealed that the incorporation of NFL@CN-X ( X = 1, 3, 5) significantly lowered the peak decomposition temperatures (T p ) of AP, RDX, HMX and CL-20 by 73.6∼81.0 °C, 1.3∼2.4 °C, 1.1∼1.5 °C, and 5.1∼7.7 °C, respectively. Correspondingly, the apparent activation energies (E a ) of the energetic composite systems markedly reduced by 113.41∼140.86 kJ·mol −1 , 3.44∼29.85 kJ·mol −1 , 32.73∼134.58 kJ·mol −1 , and 49.77∼66.74 kJ·mol −1 compared with those of the raw samples, respectively. Among these, NFL@CN-5 exhibited the most pronounced catalytic thermal decomposition effect and also significantly enhanced combustion characteristics and energy release efficiency of energetic composite systems. Ignition experiments further demonstrate that energetic systems incorporating NFL@CN-5 exhibit increased flame heights, prolonged combustion durations, and more complete combustion behavior. The NFL@CN series catalysts show great potential as superior alternatives to conventional combustion catalysts.