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.

Energetically driven reorganization of a modified catalytic surface under reaction conditions / Locatelli, A.; Sbraccia, C.; Heun, S.; Baroni, S.; Kiskinova, M.. - In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. - ISSN 0002-7863. - 127:7(2005), pp. 2351-2357. [10.1021/ja045285k]

Energetically driven reorganization of a modified catalytic surface under reaction conditions

Baroni, S.;Kiskinova, M.
2005-01-01

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.
2005
127
7
2351
2357
Locatelli, A.; Sbraccia, C.; Heun, S.; Baroni, S.; Kiskinova, M.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/16315
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