Effect of Additives and Poisons on OSC

As seen before, ceria is the major OSC component in three-way catalysts. Noble metals play a specific role in activating redox sites of ceria, which allows to record very high O storage at low temperatures. OSC properties are currently improved by 

Kacimi et al. [7] have studies the effect of various additives (V, Cr, Mn, Fe, Co, Ni, Cu and Pb) on the OSC of CeOa and Rh/Ce02 catalysts between 350 and 550°C. Co, Ni and Cu were found to promote OSC both of ceria and of Rh/ceria while Mn, V and Pb were found to be strong inhibitors. Fe and Cr showed an intermediary behavior, with either a slight promoter or a slight inhibitor effect. Among all these additives, Cu showed an exceptional effect on Rh/Ce02 improving both OSC and catalyst stability (Table 7.10). 

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