Alkaline-Enhanced Boehmite Catalysts for Catalytic Hydrolysis of Carbonyl Sulfide at Low Temperature

Abstract The removal of carbonyl sulfide (COS), a byproduct gas in the steel industry, is crucial due to its environmental impact, including acid rain formation and corrosion of chemical equipment. This study explores enhancing the catalytic performance for COS hydrolysis at low temperatures by loading potassium hydroxide (KOH) onto boehmite catalysts. The modified catalysts demonstrated significantly improved COS conversion rates and hydrogen sulfide (H2S) yields compared to untreated counterparts. At 40°C, K/Boehmite catalysts achieved approximately 80% COS conversion. As the temperature increased to 50°C, 60°C, and 70°C, COS conversion rates neared 100%, with H2S yields reaching up to 98% for K/Boehmite-3. Characterization results confirmed that KOH increased the number of active sites on the catalyst surface, enhancing COS adsorption and reaction. The KOH modification increases alkalinity and promotes the formation of surface hydroxyl groups, which play a key role in the hydrolysis reaction. These hydroxyl groups facilitate water adsorption and the breakdown of COS into H2S and CO2. This study presents a straightforward method for KOH impregnation on boehmite, marking the first use of boehmite as a COS hydrolysis catalyst, significantly boosting its efficiency and offering a viable solution for industrial COS removal while effectively generating H2S.