MANGANESE OXIDE-LANTHANUM MANGANATE PEROVSKITE-PGM COMPOSITES FOR THREE-WAY CATALYSIS

摘要

The present disclosure is directed to compositions for use in oxygen capture applications, for example in three-way catalysts (TWC) systems. In some embodiments, the compositions comprise composites of aggregated and/or fused primary particles, the aggregated and/or fused primary particles collectively having the formulae [MnO_x]_y : [La_zMnO₃]_1-y; wherein x is in a range from about 1 to 2.5; y is in a range from about 1 to about 30 wt%, or from about 1 to about 20 wt% or from about 2-10 wt% or from about 2 to about 5 wt%; and z is about 0.7 to about 1.1; and the La_zMnO₃ is a crystalline perovskite phase; the aggregated and/or fused primary particles of the composite having a mean surface area in a range of from about 25 to about 60 m2/g, preferably from about 27 to about 45 m2/g. In preferred embodiments, these compositions further comprise low levels of at least one platinum group metal (PGM), preferably Pd.