Recently, we reported the hydrothermal conversion of Fe2O3/SiO2 spheres (Fe2O3 nanoparticles supported on SiO2 spheres) into Fe2O3/Fe-Silicalite-1 nanowires in the presence of ethylenediamine and triethylamine (Micropor. Mesopor. Mater. 200 (2014) 52-60). The catalytic performance of Fe2O3/Fe-Silicalite-1 nanowires in CO oxidation, N2O decomposition, and catalytic reduction of NO by NH3 was evaluated. However, the nature of active Fe species of Fe2O3/Fe-Silicalite-1 nanowires in N2O decomposition was not clear. In the current work, additional samples (i.e., Fe-Silicalite-1, Fe2O3/Silicalite-1, and Fe2O3/Fe-Silicalite-1) were prepared by using conventional Silicalite-1 as a precursor, and tested in N2O decomposition. Fe2O3/Silicalite-1 and Fe2O3/Fe-Silicalite-1 prepared by impregnation showed higher activities than Fe-Silicalite-1 prepared by isomorphous substitution, and Fe2O3/Fe-Silicalite-1 nanowires showed the highest activity among these samples. Through relevant characterization employing XRD, XRF, N-2 adsorption, TEM, UV-vis, and Fe-57 Mossbauer spectroscopy, we conclude that small Fe2O3 nanoparticles with size of 1-2 nm are the main active Fe species for N2O decomposition, whereas framework Fe3+ and larger Fe2O3 particles are not so active. (C) 2015 Elsevier B.V. All rights reserved.