Direct promotion effect of Fe on no reduction by activated carbon loaded with Fe species

• Fe species-loaded activated carbon samples were prepared by impregnation method.
• NO reduction ability was studied under anaerobic condition, high flow velocity.
• Instrument analysis showed Fe species played a special role in NO reduction.
• Using thermodynamics analysis to evaluate the status and roles of Fe species.
• Direct promotion effect of Fe on NO reduction by carbon was clarified.

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 °C, which is a more remarkable influence on NO reduction than that of the well-known CO 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 °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 CO theory of complexes.

An activated carbon loaded with Fe species was prepared to reduce NO under anaerobic condition and studied. The role of Fe on NO reduction was clarified.Figure optionsDownload as PowerPoint slide