Catalytic hydrolysis of carbonyl sulfide over Ce-O_x@ZrO₂ catalyst at low temperature

The high applicable temperature, poor low-temperature activity and stability of current carbonyl sulfur (COS) hydrolysis catalysts greatly restrict their application in the field of blast furnace gas desulfurization. Various metal oxide carriers and rare earth oxide active components to modify the composition of catalysts. By incorporating Ce, the catalytic performance and H₂S selectivity of the modified catalysts were extensively investigated. The 15%Ce-O_x@ZrO₂ catalyst achieved a COS conversion of 80.5% and an H₂S selectivity of 80% at 90 °C. Even after 7 h of reaction, the preferred catalyst maintained a COS conversion rate above 80%. Characterization results indicated that the addition of Ce effectively increased the specific surface area of the catalyst, thereby enhancing the adsorption, diffusion and reaction of reactant molecules on its surface. Furthermore, as the loading of Ce increased, the strength of the weak base centers gradually intensified, while the amount of acid on the catalyst surface significantly decreased. These weak base sites play a vital role in the hydrolysis reaction, which ultimately accounts for the exceptional low-temperature hydrolysis performance of the 15%Ce-O_x@ZrO₂ catalyst. This study provides a theoretical basis for the preparation of rare earth catalytic materials for COS hydrolysis catalysis.