Dissociation of CO on the Ru(1 1 (2)over-bar 0) surface

The dissociation of CO on the Ru(11 (2) over tilde0) surface was investigat ed by thermal desorption spectroscopy and high resolution electron energy l oss spectroscopy (HREELS). Up to about 20% of a monolayer CO dissociates on the Ru(11 (2) over tilde0) surface at room temperature. Oxygen (68 meV) an d carbon (42 meV) are identified as dissociation products by HREELS. At tem peratures below 240 K the precursor of dissociation can be stabilized. In t his state, CO is tilted and presumably bonded at a kind of a fourfold hollo w site. During annealing, CO2 formation is observed from CO reacting with o xygen from the dissociation. (C) 2001 Elsevier Science B.V. All rights rese rved.