Comparative study of Mn/TiO2 and Mn/ZrO2 catalysts for NO oxidation

• Mn/ZrO2 shows better catalytic activity for NO oxidation than Mn/TiO2.
• Mn/ZrO2 shows the outstanding hydrothermal stability.
• MnOx accelerates the NO oxidation on the surface of the catalysts.
• ZrO2 provides both the support surfaces and the main adsorption sites.

In this paper, NO oxidation activity, sulfur resistance and hydrothermal stability of MnOx/ZrO2 and MnOx/TiO2 were studied. The results found that Mn/ZrO2 showed outstanding hydrothermal stability and better catalytic activity in comparison to Mn/TiO2, no matter in which serving conditions. Besides serving as a support material, ZrO2 also provided abundant adsorption sites for intermediate nitrates, which was beneficial for NO oxidation.

In-situ DRIFT spectra of (a) MnTiO2 and TiO2, and (b) Mn/ZrO2 and ZrO2 in NO + O2 at 250 °C.MnOx accelerates the NO oxidation on the surface of the catalysts. TiO2 only provides the support surfaces for MnOx, while ZrO2 provides both the MnOx supports and the main adsorption sites for intermediate nitrates.Figure optionsDownload as PowerPoint slide