title: CO blocking of D2 dissociative adsorption on Ru(0001).
abstract: The influence of pre-adsorbed CO on the dissociative adsorption of D(2) on Ru(0001) is studied by molecular-beam techniques. We determine the initial dissociation probability of D(2) as a function of its kinetic energy for various CO pre-coverages between 0.00 and 0.67 monolayers (ML) at a surface temperature of 180 K. The results indicate that CO blocks D(2) dissociation and perturbs the local surface reactivity up to the nearest-neighbour Ru atoms. Non-activated sticking and dissociation become less important with increasing CO coverage, and vanish at theta(CO) approximately 0.33 ML. In addition, at high D(2) kinetic energy (>35 kJ mol(-1)) the site-blocking capability of CO decreases rapidly. These observations are attributed to a CO-induced activation barrier for D(2) dissociation in the vicinity of CO molecules.
authors.affiliation: FOM Institute for Plasma Physics Rijnhuizen, Association Euratom-FOM, P.O. Box 1207, 3430 BE Nieuwegein, The Netherlands.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ueta
authors.forename: Irene M N
authors.initials: IM
authors.lastname: Groot
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gleeson
authors.forename: Steven
authors.initials: S
authors.lastname: Stolte
authors.forename: George C
authors.initials: GC
authors.lastname: McBane
authors.forename: Ludo B F
authors.initials: LB
authors.lastname: Juurlink
authors.forename: Aart W
authors.initials: AW
authors.lastname: Kleyn