We compared the reactivity of spherical particles composed of aluminum (Al) and silicon (Si) with spherical particles of Al with similar size (nominal diameter 1-2 mu m). Both particles were synthesized using a liquid atomization technique such that both particles were encapsulated in a native oxide passivation shell. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) in inert and oxidative environments were performed coupled with X-ray Diffraction (XRD) for species identification. The results showed that incorporation of Si in the Al particles lowered the melting temperature by 85 degrees C and resulted in lower apparent activation energy for the oxidation reactions and more complete combustion at lower temperatures compared with pure Al powder. Results show promise for engineering fuel particles with minor alterations in metal formulation that promote more complete combustion and energy conversion. (C) 2021 Elsevier B.V. All rights reserved.