Synergetic Zn doping and KOH etching of CeO2 for enhanced H2S oxidation via electronic structure reconstruction

This study employs a synergistic strategy of Zn doping and KOH etching to precisely regulate the physicochemical properties of CeO 2 , significantly enhancing its H 2 S catalytic oxidation performance. Experimental results indicate that Zn doping induces lattice expansion of CeO 2 , while KOH etching further removes Zn, increases Ce 3+ and oxygen vacancy concentrations, thereby optimizing surface acidity-basicity and redox capability. The obtained E-Zn/CeO 2 material exhibits excellent H 2 S conversion, reaction and kinetics, while promoting the selective formation of SO 2 . Mechanistic studies reveal that H 2 S undergoes adsorption and dissociation via μ 2 -OH/–COOH groups on the material surface, with the oxidation process following the MvK mechanism, where oxygen vacancies play a key role in adsorption and lattice oxygen transfer. Theoretical calculations further demonstrate that the synergistic modification induces reconstruction of the electronic structure of CeO 2 , including weakened covalency of Ce O bonds and a spin-state transition of O 2p orbitals, which significantly reduces the oxygen vacancy formation energy (as low as −1.47 eV) and enhances structural stability. This work provides both experimental and theoretical foundations for the rational design of highly efficient H 2 S catalytic materials.