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Title: Comparative analysis of cobalt oxide nanoisland stability and edge structures on three related noble metal surfaces: Au(111), Pt(111) and Ag(111)

Here, metal oxide nanostructures and thin films grown on metallic substrates have attracted strong attention as model catalysts and as interesting inverse catalyst systems in their own right. In this study, we investigate the role of metal support in the growth and stabilization of cobalt oxide nanostructures on the three related (111) surfaces of Au, Pt and Ag, as investigated by means of high-resolution scanning tunneling microscopy and DFT calculations. All three substrates promote the growth of crystalline CoO x (x = 1–2) islands under oxidative conditions, but we find several noteworthy differences in the occurrence and stabilization of four distinct cobalt oxide island phases: Co–O bilayers, O–Co–O trilayers, Co–O–Co–O double bilayers and O–Co–O–Co–O multilayers. Using atom-resolved images combined with analysis of defect lines in bilayer islands on Au and Pt, we furthermore unambiguously determine the edge structure. Interestingly, the island shape and abundances of edge types in bilayers change radically from mixed Co/O edge terminations on Au(111) to a predominance of Co terminated edges (~91 %) on Pt(111) which is especially interesting since the Co metal edges are expected to host the most active sites for water dissociation.
Authors:
 [1] ;  [2] ;  [3] ;  [1] ;  [2] ;  [2] ;  [1]
  1. Aarhus Univ., Aarhus (Denmark)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  3. Aarhus Univ., Aarhus (Denmark); Univ. of Manchester, Manchester (United Kingdom)
Publication Date:
Grant/Contract Number:
AC02-76SF00515
Type:
Accepted Manuscript
Journal Name:
Topics in Catalysis
Additional Journal Information:
Journal Volume: 6; Journal Issue: 10; Journal ID: ISSN 1022-5528
Publisher:
Springer
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; scanning tunneling microscopy; density functional theory; cobalt oxides; Pt(111); Au(111); Ag(111); inverse oxide/metal catalyst; water dissociation
OSTI Identifier:
1349299