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

Journal Article · Mon Oct 03 00:00:00 EDT 2016 · Surface Science

DOI:https://doi.org/10.1016/j.susc.2016.03.020· OSTI ID:1706101

Novotny, Zbynek ^[1]; Netzer, Falko ^[2]; Dohnalek, Zdenek  ^[1]

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1. BATTELLE (PACIFIC NW LAB)
2. UNIVERSITY PROGRAMS

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.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1706101
• Report Number(s): PNNL-SA-114572
• Journal Information: Surface Science, Vol. 652
• Country of Publication: United States
• Language: English

Related Subjects

Ceria
CeO2
nanoclusters
graphene
Ru(0001)
Smoluchowski ripening
STM
AES