Co-Precipitated Mn0.15Ce0.85O2−δ Catalysts for NO Oxidation: Manganese Precursors and Mn-Ce Interactions

Two Mn0.15Ce0.85O2−δmixed oxides were synthesized by a co-precipitation method using Mn(NO3)2and KMnO4as the manganese precursors, respectively. Structural analyses by X-ray powder diffraction and Raman spectroscopy reveal the formation of MnOx-CeO2solid solutions. The Mn0.15Ce0.85O2−δcatalyst prepared from the high-valent manganese precursor exhibits higher activity for the catalytic oxidation of NO. The advantage of KMnO4is related to the improved redox property of the catalyst as supported by H2temperature-programmed reduction (TPR) and O2temperature-programmed desorption (TPD). The Mn-Ce interactions create more Mn4+, Ce3+and oxygen vacancies on the KMnO4-synthesized mixed oxides based on the Raman and X-ray photoelectron spectra (XPS).Keywords:solid solutions;precursor;oxidation state;lattice defects;NO oxidation