09700841 cites 202 patents.
Synergized PGM catalyst converters configured as three-way catalyst (TWC) systems are disclosed. The disclosed SPGM system configurations exhibit high thermal stability, attenuated air to fuel (A/F) perturbations, enhanced TWC activity, and high catalytic conversion efficiency as a result of synergizing a low PGM loading close-coupled catalyst (CCC), with Ce-based oxygen storage, with a front spinel zone of suitable mixed metal oxide compositions acting as pre-catalyst for oxygen storage. The attenuation of A/F perturbations to lower amplitude, before exhaust gas emissions go into the standard PGM CCC, allows the system to work within a range of R values very close to the stoichiometric point for both lean and rich conditions, and high catalytic conversion efficiency in NOX, CO, and HC conversions. The disclosed SPGM system configurations can be utilized in a plurality of TWC applications, such as conventional TWC systems including an optional underfloor catalyst.