title: Activation of Cu(111) surface by decomposition into nanoclusters driven by CO adsorption.
abstract: The (111) surface of copper (Cu), its most compact and lowest energy surface, became unstable when exposed to carbon monoxide (CO) gas. Scanning tunneling microscopy revealed that at room temperature in the pressure range 0.1 to 100 Torr, the surface decomposed into clusters decorated by CO molecules attached to edge atoms. Between 0.2 and a few Torr CO, the clusters became mobile in the scale of minutes. Density functional theory showed that the energy gain from CO binding to low-coordinated Cu atoms and the weakening of binding of Cu to neighboring atoms help drive this process. Particularly for softer metals, the optimal balance of these two effects occurs near reaction conditions. Cluster formation activated the surface for water dissociation, an important step in the water-gas shift reaction.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
authors.forename: Baran
authors.initials: B
authors.lastname: Eren
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
authors.forename: Danylo
authors.initials: D
authors.lastname: Zherebetskyy
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA. CNR-IOM, Laboratorio TASC, Strada Statale 14, Km. 163.5, I-34149 Trieste, Italy. Physics Department and CENMAT, University of Trieste, via A. Valerio 2, I-34127 Trieste, Italy.
authors.forename: Laerte L
authors.initials: LL
authors.lastname: Patera
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA. Department of Chemistry, University of California, Berkeley, CA, USA.
authors.forename: Cheng Hao
authors.initials: CH
authors.lastname: Wu
authors.affiliation: Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bluhm
authors.affiliation: CNR-IOM, Laboratorio TASC, Strada Statale 14, Km. 163.5, I-34149 Trieste, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Africh
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
authors.forename: Lin-Wang
authors.initials: LW
authors.lastname: Wang
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA. Department of Chemistry, University of California, Berkeley, CA, USA.
authors.forename: Gabor A
authors.initials: GA
authors.lastname: Somorjai
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA. Department of Materials Science and Engineering, University of California, Berkeley, CA, USA. mbsalmeron@lbl.gov.
authors.forename: Miquel
authors.initials: M
authors.lastname: Salmeron