A series of model catalysts were prepared by using monodisperse iron oxide nanoparticles as the metal precursor and pyrolytic graphene oxides as catalyst support. The catalysts have been employed in the Fischer Tropsch Synthesis (FTS) to study the carbon support effect on the iron active phase. Remarkable catalytic discrepancies in FTS activity and product selectivity were observed, with the pyrolytic treatments of the carbon support at 873 K significantly improved the catalytic performance, particularly for the C5+ hydrocarbon yields. X-ray adsorption spectroscopy, XPS, Raman and TEM characterization techniques were used to reveal the interaction of carbon support with the active Fe species. It was found that catalytic behavior is closely associated with the evolution of surface oxygen-containing groups on the carbon supports. The carbon supports might affect the iron based FTS catalyst through a poisoning-like route of binding parts of the active sites by surface oxygen. (C) 2013 Elsevier B.V. All rights reserved.