The reaction of ethylene on a model automotive emissions control catalyst.

The reaction of ethylene on a model automotive emissions control catalyst consisting of Rh particles on an epitaxial ceria film grown on the (100) surface of an yttria stabilized zirconia single crystal was studied using TPD. The TPD results showed that ethylene undergoes dehydrogenation on the model catalyst at temperatures below 500 K depositing carbon on the Rh particles. Surface carbon formed in this manner was oxidized to CO upon heating to above 550 K using oxygen supplied by the ceria lattice. Heating to 900 K was found to induce reduction of the ceria film resulting in a marked decrease in oxidation activity. [ABSTRACT FROM AUTHOR]