Deactivation of Automotive Catalysts

One of the challenges associated with catalysis is catalyst deactivation. This example shows how the performance of a three way exhaust catalyst can deteriorate due to “cold start” conditions. These catalysts consist of platinum and rhodium on an oxide support.

The LEIS spectrum of the surface of the fresh catalyst shows a clear platinum peak. When the catalyst has been used under “cold start” conditions, this peak disappears, because the platinum is covered by coke. The covered platinum is no longer available for the catalytic reaction and this causes a poor performance of the catalyst.
The coke can be removed in a regeneration step. The platinum is clean and available for the catalytic reaction and the catalyst’s properties are restored.

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