Enhancing charge separation efficiency of CuBi2O4 via Fe-doping strategy for catalytic thermal decomposition of energetic materials

Ammonium perchlorate (AP), cyclotrimethylenetrinitramine (RDX) and 1,1’-dihydroxy-5,5’-ditetrazolium dihydroxyl ammonium (TKX-50) play a vital role in aerospace and military applications. However, improving their thermal decomposition performance remains a critical technical bottleneck. In this study, CuBi 2 O 4 (CBO) was selected as combustion catalyst due to its superior thermal stability and structural tunability, and Fe doping strategy was introduced to modulate its electronic band structure. The effective incorporation of Fe in CBO not only induces lattice distortion, but also stabilizes the thermodynamic nonequilibrium state, thereby reducing the energy barrier for electron transfer and effectively suppressing carrier recombination. Fe-CBO exhibits narrow band gap (1.73 eV), excellent electron transport properties and abundant active sites, which can significantly improve catalytic performance. Systematic optimization of Fe-doping contents reveals that 15 %Fe-CBO has optimal catalytic performance, reducing thermal decomposition peak temperatures of AP, RDX, and TKX-50 by 76.3, 5.7 and 36.3 °C respectively, while lowering apparent activation energies to 125.26, 182.34 and 164.60 kJ·mol −1 . Laser ignition experiments further demonstrates that 15 %Fe-CBO can enhance flame brightness, expand the flame propagation area of AP, RDX and TKX-50, and reduce the time to achieve stable combustion. Moreover, the burning rate of the AP-based composite solid propellant is increased by 1.95 times after the introduction of 15 %Fe-CBO. The decomposition mechanism of AP, RDX, and TKX-50 catalyzed by 15 %Fe-CBO was proposed based on valence band theory and comprehensive experimental characterization. Fe-doping strategy provides a novel approach for the design of efficient combustion catalysts.