CO oxidation over MnO2 catalysts prepared by a simple redox method: Influence of the Mn (II) precursors

• MnO2 catalysts were prepared at room temperature by simple redox methods.
• The effect of Mn2+ precursors was studied in the oxidation of CO.
• MnO2 catalyst prepared from Mn-chloride shows excellent activity.
• The catalytic activity is correlated with the amount of labile oxygen species.

MnO2 was prepared by a simple redox method using potassium permanganate and various Mn2+ precursors (Mn-chloride, Mn-nitrate, Mn-acetate, and Mn-sulfate) and the influence of Mn-precursors in the CO oxidation was investigated. The light-off temperatures (T50%) in the dry conditions increased as following order: Mn-chloride < Mn-nitrate < Mn acetate < Mn-sulfate. In the presence of CO2 and H2O vapor, the T50% value significantly shifted to higher temperatures compared to its value in the absence of them. MnO2 catalyst prepared from Mn-chloride exhibited a high quantity of labile oxygen and better reducibility compared with the other catalysts.

The CO2 is formed by reaction between gas phase CO and labile oxygen species of the catalysts. The catalytic performance for CO oxidation is closely correlated with the quantity of CO2 formation of the MnO2 catalysts.Figure optionsDownload as PowerPoint slide