Characterization of α-Fe₂O₃/γ-Al₂O₃ Catalysts for Catalytic Wet Peroxide Oxidation of <i>m</i>-Cresol

Abstract

Fe/γ-Al2O3 catalysts calcined at different temperatures were evaluated in the catalytic wet peroxide oxidation (CWPO) of m-cresol. BET, XRD, and 57Fe Mössbauer spectroscopy (MS) were used to characterize the catalysts and showed that the calcination temperature changed the crystal particles of α-Fe2O3 and the interactions between α-Fe2O3 and the γ-Al2O3 support. The reaction-condition experiments showed that changing the reaction conditions to higher reaction temperature and acidic pH promoted the degradation of m-cresol. m-Cresol was degraded completely, and TOC removal reached 51.0% after CWPO for 2 h at an initial pH of 4 and a temperature of 60 °C over an Fe/γ-Al2O3 catalyst calcined at 350 °C (Fe/γ-Al2O3-350). Both reactions for 10 consecutive reaction cycles and for 120 continuous hours in a fixed-bed reactor showed that the Fe/γ-Al2O3-350 catalyst was stable and a promising catalyst for heterogeneous CWPO. The degradation intermediates were identified by GC-MS, and the possible degradation pathway of m-cresol was investigated.