Engineering regulation of oxygen vacancies and hydroxyl oxygen groups for low-temperature catalytic hydrolysis of carbonyl sulfide

The deep purification of carbonyl sulfide (COS) is crucial for improving natural gas utilization and promoting environmental sustainability. In this study, a series of modified Cu-Zr/ZnAlOx catalysts was synthesized for COS catalytic hydrolysis, and the regulatory mechanisms of alkali modification and nitrogen doping were systematically investigated. Alkali modification promotes COS hydrolysis and H 2 S oxidation by converting Cu + to Cu 2+ (reducing oxygen vacancies), transforming hydroxyl groups into ·OH, and catalyzing ·O 2 - to 1 O 2 (accelerating the oxidation of H 2 S and elemental sulfur). Nitrogen doping inhibits the direct conversion of H 2 S/elemental sulfur to SO 2 (enhancing oxidation selectivity) by promoting lattice oxygen-to-adsorbed oxygen conversion (increasing oxygen vacancies), forming metal-nitrogen bonds (M–N, conducive to ·OH generation), and suppressing ·O 2 - to 1 O 2 conversion. The synergistic effect of alkali modification and nitrogen doping enhances H 2 O dissociation and C–S bond cleavage during COS hydrolysis, while improving the selectivity of H 2 S oxidation to elemental sulfur. This work provides new insights into the synergistic regulation of dual modifications for efficient COS catalytic hydrolysis.