ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A study on simultaneous catalytic ozonation of Hg⁰ and NO using Mn–TiO₂ catalyst at low flue gas temperatures

Ping Zhang, Wei-guo Pan, Rui-tang Guo, Shu-ming Liu, Ming-yuan Li, Ling Qin, Xiao-qing Pan, and Xia-feng Ye

Shanghai University of Electric Power, Shanghai, People’s Republic of China

E-mail: grta@zju.edu.cn

Abstract: Mn–TiO₂ catalysts were utilized as an ozonation catalyst for the first time to study the simultaneous catalytic ozonation of Hg⁰ and NO at low flue gas temperatures. BET, SEM–EDS, XRD, XPS, H₂-TPR, NO _x -TPD and Hg⁰-TPD were used to characterize the catalysts. The Mn–TiO₂ catalyst, in which the molar content of metal Mn was 60%, exhibited the best catalytic activities of Hg⁰ and NO oxidation, compared with other Mn–TiO₂ catalysts. It was found that within the range of experiment, the catalytic ozonation efficiency of Hg⁰ and NO was higher than that of ozonation or catalytic oxidation. The results also showed that the presence of NO gas inhibited the catalytic ozonation of elemental mercury, and the inhibition was enhanced with the NO inlet concentration, while few elemental mercury molecules did promote the catalytic ozonation of NO. The addition of H₂O vapor promoted the catalytic ozonation of Hg⁰ and NO. In addition, 0.6Mn–TiO₂ catalyst demonstrated a good TOS and cyclic stability. The catalytic ozonation of NO and Hg⁰ on Mn–TiO₂ catalyst likely followed the Langmuir–Hinshelwood mechanism, where the hydroxyl radicals reacted with adjacently adsorbed NO molecules and elemental mercury on catalyst surface.

Keywords: Mn–TiO₂ catalyst ; Catalytic ozonation ; NO ; Hg⁰ 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-018-0388-8

Chemical Papers 72 (6) 1347–1361 (2018)