The porous Fe-based catalysts supported on polystyrene mesoporous carbon were studied in the Fischer-Tropsch Synthesis. The solids were pretreated at different calcination temperatures and their characterizations were examined by X-ray diffraction (XRD), Raman spectroscopy, Scanning and Transmission electron microcopies (SEM and TEM), textural properties, elemental composition by X-ray dispersive spectroscopy (EDS), temperature programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). It was shown that the preexistent carbides phases, obtained upon using elevated temperatures of calcinations procedure, were not completely reoxidized during the reaction, while the formation of carbides through the polymeric carbon reaction with magnetite and/or metallic iron resulted in highly active catalyst for FTS. (C) 2016 Elsevier B.V. All rights reserved.