Adsorption of oxygen and oxidation of CO on the ruthenium (001) surface
Abstract
The adsorption of oxygen on the ruthenium (001) surface has been studied using a combination of techniques: LEED/Auger, Kelvin probe contact potential changes, and flash desorption mass spectrometry. Oxygen is rapidly adsorbed at 300 K, forming an ordered LEED structure having apparent (2 × 2) symmetry. Two binding states of oxygen are inferred from the abrupt change in surface work function as a function of oxygen coverage. LEED intensity measurements indicate that the oxygen layer undergoes an order-disorder transition at temperatures several hundred degrees below the onset of desorption. The order-disorder transition temperature is a function of the oxygen coverage, consistent with two binding states. A model involving the adsorption of atomic oxygen at θ < 0.5 and the formation of complexes with higher oxygen content at θ > 0.5 is proposed. The oxidation of CO to form CO 2 was found to have the maximum rate of production at a ruthenium temperature of 950 K.
- Publication:
-
Surface Science
- Pub Date:
- March 1975
- DOI:
- 10.1016/0039-6028(75)90409-4
- Bibcode:
- 1975SurSc..48..304M