Tailoring the Composition of BaxBO3 (B = Fe, Mn) Mixed Oxides as CO or Soot Oxidation Catalysts in Simulated GDI Engine Exhaust Conditions

Abstract

Mixed oxides with perovskite-type structure (ABO3) are promising catalysts for atmospheric pollution control due to their interesting and tunable physicochemical properties. In this work, two series of BaxMnO3 and BaxFeO3 (x = 1 and 0.7) catalysts were synthesized using the sol–gel method adapted to aqueous medium. The samples were characterized by μ-XRF, XRD, FT-IR, XPS, H2-TPR, and O2-TPD. The catalytic activity for CO and GDI soot oxidation was determined by temperature-programmed reaction experiments (CO-TPR and soot-TPR, respectively). The results reveal that a decrease in the Ba content improved the catalytic performance of both catalysts, as B0.7M-E is more active than BM-E for CO oxidation, and B0.7F-E presents higher activity than BF for soot conversion in simulated GDI engine exhaust conditions. Manganese-based perovskites (BM-E and B0.7M-E) achieve better catalytic performance than iron-based perovskite (BF) for CO oxidation reaction due to the higher generation of actives sites.