Activated carbon materials loaded with Fe species were prepared via an impregnation method and studied. Various analyses showed good dispersion of Fe species on the activated carbon surface when the loading amount did not exceed 2 g of iron(III) nitrate nonahydrate on 10 g of activated carbon. Additionally, the simultaneously existing forms of Fe species on the activated samples were found to be Fe3O4, FeO, and elemental Fe(0). NO reduction experiments under anaerobic conditions showed that the loading of Fe species enhanced the NO reducing ability from an NO conversion of (28 to 86)% at 850 degrees C, which is a more remarkable influence on NO reduction than that of the well-known C-O complexes. Thermodynamic analysis and detailed experimental results led to a new mechanism with two independent routes, both of which require Fe participation and proceed at temperatures below and above 800 degrees C, respectively, and generate different COx products. Furthermore, one of the routes was more efficient in reducing NO than the other. This mechanism explained the experiments much better than the existing C-O theory of complexes. (C) 2015 Elsevier Ltd. All rights reserved.