Advantageous Role of N-doping on K@Al in COS/CS2 Hydrolysis: Diminished Oxygen Mobility and Rich basic sites

Basic sites are important to promote carbonyl sulfide (COS) and carbon disulfide (CS 2 ) hydrolysis activity while improving the oxidation resistance of hydrolysis catalysts is a challenge. Here, we report an N -doped alumina-based catalyst ( N -K@Al), where the complete hydrolysis removal of COS and CS 2 by the N -doped catalyst was extended up to 15 h at 160 °C, and the turnover frequency (TOF) value of the catalyst was increased from 0.85 × 10 -2 s −1 to 1.16 × 10 -2 s −1 . The results showed that the strong interaction between nitrogen and potassium decreased the reactive oxygen density and activated –OH, weakening the oxygen mobility. In addition, the beneficial effects of N -doped included the addition of moderately and weakly basic sites by pyridine N. The optimized N -K@Al showed good catalytic performance in the hydrolysis of COS and CS 2 removal with lower reaction temperature and higher total hydrogen sulfide yield. Density functional theory calculations revealed that N -K@Al reduced the Gibbs free energy of COS and CS 2 hydrolysis to 0.21 eV and 0.33 eV, respectively, contributing to the enhanced catalytic activity. The present study presents new strategies for developing efficient antioxidant organosulfur hydrolyzers and other practical industries.