Search Results

To clarify the thermal deterioration mechanism of three-way catalysts quantitatively, we investigated the relationship between the catalytic performance and the catalyst characteristics for thermally aged Pt/Rh catalysts. 1. Experimentally, the HC oxidation reaction, which occurs on the surface of Pt/Rh particles on catalysts, is approximated by a first-order reaction of HC concentration with a constant activation energy. 2. The relationship between the Pt mean diameter D and the HC 50% conversion temperature T50 is described by the following equation; where E and kB are the activation energy of the reaction and the Boltzman constant, respectively. 3. The sintering rate of Pt particles on the three-way catalysts was found to depend on the aging temperature(T) of catalyst and the concentration of oxygen in the gas phase([O2]).