IMPROVEMENT OF THERMAL STABILITY OF COPPER-MANGANESE SPINEL AS ZERO PGM CATALYST FOR TWC APPLICATION

摘要

Effect of the type of ZPGM material composition to improve thermal stability of ZPGM catalyst systems for TWC application is disclosed. ZPGM catalyst system samples are prepared and configured with washcoat on ceramic substrate, overcoat including doped Zirconia support oxide, and impregnation layer including either Cu₁Mn₂O₄ spinel or Cu₁Co₁Mn₁O₄ spinel. Testing of ZPGM catalyst samples including variations of aging temperatures and different impregnation layer materials are developed under isothermal steady state sweep test condition for ZPGM catalyst systems to evaluate performance especially NOx conversions and level of thermal stability. As a result disclosed ZPGM catalyst systems with most suitable spinel that includes Cu₁Co₁Mn₁O₄ in impregnation layer exhibit high NOx conversion and significant improved thermal stability compare to Cu₁Mn₂O₄ spinel, which is suitable for under floor and close coupled TWC application. The effect of adding Co to Cu-Mn spinel composition to improve thermal stability confirmed by TPR measurement.