Measurements of Oxygen Species Available in PtRh/CeO2–Al2O3 Type Industrial Catalysts and Relationship with Their Three-Way Catalytic Activity

Measurements of the oxygen storage capacity (OSC) were performed on several aged PtRh/CeO2–Al2O3 industrial catalysts, using different techniques, i.e., TPR experiments, O2 and H2/O2 chemisorption. The obtained OSC values were compared to the catalytic activity measured at 723 K in the simultaneous elimination of CO, C3 hydrocarbons and NO. The best correlation was found for the OSC measured by O2 chemisorption at 298 K on the solids previously reduced at 573 K and which represents the most reactive oxygen atoms of the catalyst surface.