Catalytic ozonation of dichloromethane at low temperature and even room temperature on Mn-loaded catalysts

Five Mn-loaded catalysts were synthesized on γ-Al(2)O(3), TiO(2), ZrO(2), nano γ-Al(2)O(3) and nanoZrO(2) supports. The catalytic ozonation of DCM (dichloromethane) was evaluated under industrial conditions (i.e., temperature, O(3) input, H(2)O and SO(2) content). According to results, >90% DCM conversion without O(3) residue was achieved for all samples at 120 °C and an O(3)/DCM ratio of 6. At 20–120 °C, the highest Mn(3+) content, abundant surface oxygen species and more weak acid sites led to the best performance of Mn/nanoAl(2)O(3) (M/A-II). At 20 °C and 120 °C, 80% and 95% DCM can be degraded respectively on M/A-II at 20 °C with matched surface oxygen species and acidity. An O(3)/DCM ratio of 6 was optimal for performance and economy. For the effects of complex exhaust, both H(2)O and SO(2) deactivated M/A-II. The H(2)O-induced deactivation was recoverable and also removed surface-deposited chlorine-containing species, enhancing the HCl selectivity. Finally, the Cl equilibrium of the reaction was comprehensively analyzed.