Optimization of regeneration conditions for ozone decomposition catalysts via thermal treatment and hydrogen reduction

Abstract This study synthesized a Mn-based catalyst using a potassium permanganate-assisted precipitation method and investigated its catalytic activity and deactivation behavior in ozone decomposition. The spent catalyst was regenerated via thermal treatment and hydrogen reduction. Ozone decomposition experiments combined with XRD and XPS analyses revealed that the accumulation of surface-adsorbed oxygen species significantly reduced the catalytic activity of Mn-based catalysts by blocking active sites. This accumulation is closely linked to the rate-limiting step in the decomposition mechanism—namely, the desorption of oxygen species. Regeneration methods of spent catalysts were explored using thermal treatment (100–600 °C) and hydrogen reduction (40 °C and 60 °C). Thermal treatment (100–500 °C) restored up to ~ 57.5% of activity at 300 °C, whereas hydrogen reduction at 60 °C achieved ~ 55% recovery under energy-efficient conditions. Notably, hydrogen reduction selectively removed adsorbed oxygen species even at low temperatures, offering a promising alternative to conventional thermal regeneration methods.