Nanochromates MCrO (M = Co, Ni, Cu, Zn): Preparation, Characterization, and Catalytic Activity on the Thermal Decomposition of Fine AP and CL-20.

The chromate nanoparticles such as CoCrO, NiCrO, CuCrO, and ZnCrO were prepared by a modified sol-gel method. The structural and morphological properties of the chromate nanoparticles were characterized by X-ray diffraction (XRD) and a scanning electron microscope (SEM). The catalytic effects of chromates on the thermal decomposition of fine ammonium perchlorate (FAP) and hexanitrohexaazaisowurtzitane (CL-20) were studied by the TG-DTG measurements. Results show that the addition of CoCrO, NiCrO, CuCrO, and ZnCrO nanoparticles makes the activation energies for the thermal decomposition of FAP decrease by 93.9, 94.0, 83.1, and 67.0 kJ·mol, and the thermal decomposition temperatures decrease by 45.0, 24.9, 57.7, and 38.8 K respectively. On the other hand, a similar trend exists in the case of the thermal decomposition of CL-20. Therefore, the addition of nanochromates shows high catalytic efficiency on the thermal decomposition of both FAP and CL-20 components, which would be beneficial to promote the burning rate of propellants containing FAP and CL-20 components.