Simultaneous removal of NOx and soot particulates over La0.7Ag0.3MnO3 perovskite oxide catalysts

A highly active catalyst (La0.7Ag0.3MnO3) for simultaneous removal of nitrogen oxides (NOx) and diesel soot is synthesized by solid state method and the catalyst is characterized by XRD, FT-IR, H2-TPR, and O2-TPD. The results indicate that metallic Ag appears in the La0.7Ag0.3MnO3 catalyst. The concentration of oxygen vacancy and the over-stoichiometry oxygen content also remarkably increase as the substitution increase of Ag+ for La3+ at A-site ions. The simultaneous removal of soot particulates and NOx activities are evaluated by a temperature-programmed reaction (TPRe) technique. The superior performance of the La0.7Ag0.3MnO3 catalyst for the reaction is probably due to lots of oxygen vacancy and over-stoichiometry oxygen in the perovskite lattice along with the zero-valence silver.