Fe-B amorphous nanoalloy materials have been synthesized by chemical reduction method using various iron precursors and preparation mediums. The samples have been characterized by X-ray diffraction, inductively coupled plasma atomic emission spectroscopy, N-2 sorption, transmission electron microscopy, X-ray photoelectron spectroscopy, differential scanning calorimetry, and electron diffraction. A series of studies have been performed to elucidate the influences of preparation parameters on the properties of Fe-B nanoalloys. The characterization results indicated that the amorphous nature of Fe-B materials remained up to 400 degrees C and the presence of boron retarded the crystallization of Fe sample. The iron precursor and preparation medium play a critical role in determining the structure, morphology, and composition of Fe-B nanoalloys. The iron precursors have a significant influence on the oxidation states of iron and boron species in Fe-B nanoalloys. The catalytic activities of Fe-B nanoalloys have been investigated by subjecting them for dehydrogenation of ethanol as a probe reaction. The results indicated that Fe72.8B27.2, prepared using FeCl3 in aqueous medium, showed high activity for dehydrogenation of ethanol owing to its high surface area and turnover frequency.