Controlled Preparation and Performance Study of Iron Single-Atom Catalysts Loaded on Micron-Sized Aluminum Powder

To improve the combustion efficiency of micron-sized aluminum powder and its catalytic performance for energetic molecules, iron single-atom catalysts (Fe₁/Al) loaded on micron-sized aluminum powder are prepared using the chemical vapor transport (CVT) method in this study. The loading amount, structure, and physicochemical properties of the single-atom catalysts are characterized using inductively coupled plasma optical emission spectrometry (ICP-OES), aberration-corrected scanning transmission electron microscopy (AC-STEM), X-ray absorption fine structure spectroscopy (XAFS), and X-ray photoelectron spectroscopy (XPS). Thermogravimetric differential scanning calorimetry (TG-DSC) is used to compare the thermal reaction performance of the materials before and after modification by CVT method, and the catalytic decomposition performance of a series of materials on dihydroxylammonium 5, 5'-bistetrazole-1, 1'-diolate (TKX-50) is investigated. Results indicate that the iron species on the surface of the catalysts prepared by the CVT method exhibit a high degree of atomic-level dispersion. The CVT method allows for controlled preparation in terms of iron single-atom content and catalyst yield. The thermal reaction performance of the series of single-atom catalysts, as well as their catalytic decomposition performance on TKX-50, show significant improvements compared to unmodified aluminum powder. Among them, the Fe₁/Al catalyst with a loading of 5.0% iron exhibits the best catalytic effect on TKX-50. with a peak temperature of the thermal catalytic decomposition reaction reduced by 19.3 °C and 39.1 °C compared to unmodified aluminum powder. This study achieves the controlled preparation of single-atom combustion catalysts loaded on aluminum powder, providing a new method and approach for the modification of micron-sized aluminum powder.