Enhancement of resistance to chlorine poisoning of Sn-modified MnCeLa catalysts for chlorobenzene oxidation at low temperature

Abstract

In this article, MnCeLa and Sn-MnCeLa mixed oxide catalysts prepared by a sol–gel and coprecipitation method were evaluated for the catalytic combustion of chlorobenzene (CB), which was employed as a model compound for volatile organic chlorinated aromatics. The activity tests revealed that both catalysts presented an excellent activity in catalytic destruction of CB showing 90% conversion below 210 °C. A considerably higher stability was observed for the Sn-MnCeLa catalyst compared with the MnCeLa sample, indicating that the catalytic stability of the MnCeLa catalyst for chlorobenzene oxidation could be significantly enhanced via the introduction of Sn. X-ray photoelectron spectroscopy (XPS) demonstrated that Sn modification can increase the concentration of surface reactive oxygen species, which is critical to remove Cl species. Additionally, Raman and hydrogen temperature programmed reduction (H₂-TPR) showed that the addition of Sn inhibited the formation of MnO_xCl_y on the active sites of the MnCeLa catalyst. These two aspects are responsible for the remarkably improved resistance to chlorine poisoning of the Sn-modified MnCeLa catalyst.