The exhaust of a gasoline engine is a demanding environment that obligates TWC to operate at low temperature, withstand thermal peaks up to about 1000ºC, tolerate the presence of poisons, especially sulfur species and lead (in the past), and not to be affected by gas flow pulsations and severe mechanical vibrations [1]. Catalytic systems were first introduced to control exhaust emissions in vehicles in the 1970s, and to fulfill all these requirements, the composition of TWC has been improved since early formulations.