Removal of toxic polychlorinated aromatic hydrocarbons (PCAHs) with cheap, efficient, and environmentally friendly catalysts has long been considered a challenging issue. We synthesized novel catalysts which were made from CaCO3/Fe2O3 nanorods. These catalysts oxidized PCAHs and were characterized using numerous analytical techniques. The catalytic activity was evaluated using 1,2-dichlorobenzene (o-DCB), as a model PCAH compound. The results demonstrated that the catalyst (FeCa3) with 2.8 mol% Ca-doping shows superior catalytic activity, with the complete o-DCB oxidization at a lower temperature (350 degrees C) than other reported CaCO3/alpha-Fe2O3 nanocomposites (450 degrees C). Also, we demonstrated that the catalytic activity and stability increased in the presence of water vapor which differs from previous studies. We attribute the excellent catalytic activity to the unique surface morphology and interfacial microstructure composed of CaCO3,and alpha-Fe2O3 nanorods, which play a crucial role in enhancing catalytic activity and stability in a humid atmosphere. The intermediates (formate, acetate, and maleate) and final products (CO2 and H2O) were monitored by in situ FTIR spectroscopy. In summary, we demonstrated that our CaCO3/Fe2O3 nanorod catalysts are promising catalysts for the oxidation of PCAHs. (C) 2016 Elsevier B.V. All rights reserved.