The generation of hydroxyl radicals by hydrogen peroxide decomposition on FeOCl/SBA-15 catalysts for phenol degradation.

Iron oxychloride (FeOCl) supported on mesoporous silica (SBA-15), as a Fenton-like solid catalyst for phenol degradation, showed supreme activity for production of hydroxyl radical (HO·) by H₂O₂ decomposition, and the generation capacity was comparable to the conventional Fenton reagent (Fe²⁺+H₂O₂). The structure of FeOCl was characterized with spectroscopies. The generation of HO· species during the reaction was detected using 5,5-dimethyl-1-pyrroline N-oxide trapped electron paramagnetic resonance. Furthermore, the kinetics in detail was driven for the creation and diffusion of HO· by H₂O₂ decomposition over FeOCl, which follows a first-order rate through a two-step reaction. With the combination of the catalyst structure and kinetic parameters, the plausible mechanism for H₂O₂ decomposition during the oxidative degradation of phenol was rationalized. As a Fenton-like solid catalyst, FeOCl/SBA-15 is a promising alternative for the removal of low-level organic contaminates from water. © 2014 American Institute of Chemical Engineers AIChE J, 61: 166-176, 2015 [ABSTRACT FROM AUTHOR]