K-promoted oxidation of CO on Ni(111)

The oxidation of CO promoted by K atoms is observed on Ni(111) for temperatures ranging from room temperature down to 160 K. The catalytic reaction at 160 K gives rise to the formation of adsorbed CO₂ molecules which are stable up to 180 K, above that temperature they completely desorb. The reaction follows the Langmuir-Hinshelwood mechanism and the uptake order of the involved species seems to be of minor importance.