The experimental and mechanism study of novel heterogeneous Fenton-like reactions using Fe3-xTixO4 catalysts for Hg0 absorption

Novel heterogeneous Fenton-like Fe3-xTixO4 catalysts prepared by co-precipitation method were used for Hg-0 absorption in a self-designed bubbling reactor system. Characterization by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed that Ti successfully entered the structure of Fe3-xTixO4 catalysts and was enriched on the surface of Fe3-xTixO4. Important factors affecting Fe3-xTixO4 catalysts activity toward Hg-0 absorption, such as H2O2 concentration and Ti content in Fe3-xTixO4, were considered. Results showed that Fe3-xTixO4 can effectively decompose H2O2 to generate highly reactive center dot OH radicals, and oxidize Hg-0 to Hg2+ in Fenton-like solutions. The mechanism model of Hg-0 absorption by heterogeneous Fenton-like reaction was preliminarily established. Theoretically calculated results using the model well agreed with the experimental results, indicating that Hg-0 absorption is simultaneously controlled by solid-liquid surface oxidation and gas-liquid film oxidation. These findings can help investigations on the mechanism of Hg-0 absorption by the heterogeneous Fenton-like reaction. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.