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This content will become publicly available on March 22, 2017

Title: Ceria nanoclusters on graphene/Ru(0001): A new model catalyst system

In this study, the growth of ceria nanoclusters on single-layer graphene on Ru(0001) has been examined, with a view towards fabricating a stable system for model catalysis studies. The surface morphology and cluster distribution as a function of oxide coverage and substrate temperature has been monitored by scanning tunneling microscopy (STM), whereas the chemical composition of the cluster deposits has been determined by Auger electron spectroscopy (AES). The ceria nanoparticles are of the CeO2(111)-type and are anchored at the intrinsic defects of the graphene surface, resulting in a variation of the cluster densities across the macroscopic sample surface. The ceria clusters on graphene display a remarkable stability against reduction in ultrahigh vacuum up to 900 K, but some sintering of clusters is observed for temperatures > 450 K. The evolution of the cluster size distribution suggests that the sintering proceeds via a Smoluchowski ripening mechanism, i.e. diffusion and aggregation of entire clusters.
 [1] ;  [2] ;  [1]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Karl-Franzens Univ., Graz (Austria)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 0039-6028; PII: S0039602816300231
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Surface Science
Additional Journal Information:
Journal Volume: 1021; Journal Issue: C; Journal ID: ISSN 0039-6028
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Org:
Country of Publication:
United States
77 NANOSCIENCE AND NANOTECHNOLOGY ceria; CeO2; nanoclusters; graphene; Ru(0001); smoluchowski ripening; STM; AES