Highly Efficient and SO2 resistance of Pr-doped OMS-2 catalyst for CO oxidation

The catalytic oxidation of carbon monoxide (CO) is an effective method for CO removal. However, developing catalysts that exhibit both high activity and resistance to sulfur dioxide (SO ₂ ) remains a significant challenge. In this study, OMS-2 and Pr _X -OMS-2 catalysts were synthesized via a one-pot hydrothermal method. The results of physicochemical characterization revealed that the Pr-modified OMS-2 catalyst increased the specific surface area, enhanced the adsorption capacity of oxygen species, improved the distribution of surface elements, and lowered the reduction temperature of the OMS-2 catalyst during catalytic reactions. The Pr _13% -OMS-2 catalyst achieved complete CO conversion at 140 °C and maintained over 90% CO conversion at 300 °C in the presence of 100 ppm SO ₂ , significantly outperforming the pure OMS-2 catalyst. The SO ₂ resistance is attributed to the ability of Pr to suppress the electron transfer between SO ₃ and Mn, effectively protecting the Mn atoms and preserving high catalytic activity in the presence of SO ₂ .