Mn-supported γ-Al ₂ O ₃ and SiO ₂ catalysts for ozone-induced oxidation of <i>m</i> -cresol: role of pH and catalyst support

Abstract Catalytic ozonation using metal oxides is a promising method for the degradation of persistent organic pollutants like m -cresol. In this study, we explored Mn-supported γ-Al 2 O 3 and SiO 2 for the ozonation of m -cresol (as a model phenolic contaminant) under ambient conditions. The structural and chemical properties of catalysts (2.5 wt% Mn) were determined using TEM, SEM, XRD, FT-IR, and EDX technique. Mn catalysed and uncatalysed ozonation were performed under controlled conditions using activated charcoal (as reference standard) for 24 h by sampling at regular intervals. Kinetic analysis demonstrated a similar trend in activity: 2.5 % Mn/SiO 2 &gt; 2.5 % Mn/γ-Al 2 O 3 &gt; activated charcoal, showing enhanced catalytic character for SiO 2 . Post-reaction studies of degradation intermediates were performed using GC-MS analysis to establish the direction of the reactions. The findings highlight the significant role of support material selection (e.g., high surface area of SiO 2 vs. acidic sites on γ-Al 2 O 3 ) in achieving maximum ozone activation and pollutant mineralization.