title: Energetically driven reorganization of a modified catalytic surface under reaction conditions.
abstract: The compositional and structural rearrangements at the catalyst surface during chemical reactions are issues of great importance for understanding and modeling the catalytic processes. Low-energy electron microscopy and photoelectron spectromicroscopy studies of the real-space structure and composition of a Au-modified Rh(110) surface during water formation reveal reorganization processes due to Au mass transport triggered by the propagating reaction fronts. The temporal evolution of the surface reaction results in a 'patterned' surface consisting of separated Au-rich and Au-poor phases with different oxygen coverage, Rh surface structure, and reactivity. The experimental results are complemented by ab initio electronic-structure calculations of the O and Au adsorption phases, which demonstrate that the reorganization of the Au adlayer by the propagating reaction fronts is an energetically driven process. Our findings suggest that reaction-induced spatial inhomogeneity in the surface composition and structure is a common feature of metal catalysts modified with adatoms which become mobile under reaction conditions.
authors.affiliation: Sincrotrone Trieste S.C.p.A., S.S. 14, km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy. andrea.locatelli@elettra.trieste.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Locatelli
authors.forename: Carlo
authors.initials: C
authors.lastname: Sbraccia
authors.forename: Stefan
authors.initials: S
authors.lastname: Heun
authors.forename: Stefano
authors.initials: S
authors.lastname: Baroni
authors.forename: Maya
authors.initials: M
authors.lastname: Kiskinova