Promoting effect of Co-doped CeO2 nanorods activity and SO2 resistance for Hg0 removal

A simple hydrothermal method for doping cobalt species into CeO2 nanorods to prevent deactivation of ceria and provide additional active sites for Hg-0 removal. The materials were extensively characterized by XRD, SEM, HRTEM, H-2-TPR, Raman, XPS, and Hg-TPD techniques. The introduction of Co improves the reduction properties and greatly enhances the activity of CeO2 for Hg-0 removal. On the basis of the prepared materials, 0.2Co/Ce nanorods with a well-defined (110) surface display excellent performance with more than 95% Hg-0 removal efficiency at 19099 h(-1 )gas hourly space velocity (GHSV) from 100 to 200 degrees C, as well as good resistance to SO2 and H2O. According to the Hg-TPD results, HgO was the major product over Co doped CeO2 nanorods. DFT studies have shown that Co doping can increase the adsorption energy of Hg-0 and promote the formation of oxygen vacancies, which all contribute to the enhanced activity of Hg degrees removal. The oxidation of Hg-0 over Co-doped CeO2 nanorods through a Mars-van Krevelen mechanism, where Hg-0 react with surface oxygen to form HgO. Moreover, the synergistic effect between Ce4+ and Co2+ inhibits the oxidation of SO2 to surface sulfate, preventing the CeO2 from being deactivated.

Automated summary

A simple hydrothermal method is used to dope cobalt species into CeO2 nanorods, which improves the reduction properties and activity of CeO2 for Hg-0 removal. Co doping increases the adsorption energy of Hg-0 and promotes the formation of oxygen vacancies, leading to enhanced activity for Hg degrees removal. The oxidation of Hg-0 over Co-doped CeO2 nanorods occurs through a Mars-van Krevelen mechanism, where Hg-0 reacts with surface oxygen to form HgO.