Oxygen adsorption on spontaneously reconstructed Au(511)
The four-fold site on {100} facets, which are potential catalytic sites on high-curvature gold nanoparticles, is difficult to prepare on a gold single crystal due to surface reconstruction. In this work, the Au(511) surface with a high density of step edges and a well-maintained {100} local structure was studied by scanning tunneling microscopy (STM), temperature programmed reaction spectroscopy (TPRS), and density functional theory (DFT) calculations. Annealing at 550 K and 870 K induces reconstruction on the Au(511) surface to a mixture of (311) and (711) micro-terraces. At room temperature and low oxygen coverage, oxygen adsorbs at both three- and four-fold sites on the surface, leading to a well-ordered zig-zag structure. Oxygen atoms cause significant orbital hybridization and a slight displacement of the gold atoms to which they bind. High oxygen coverages induce the formation of clusters, which are not active towards oxidation of isopropanol at room temperature and a pressure of 10-10 mbar. Oxygen adsorption saturates at 1 monolayer (ML), and two separate oxygen recombinative desorption peaks were observed at coverages above 0.11 ML. Our characterization of this surface and the O adsorption structure offers future studies of {100} micro-terraces for oxidation reactions, which contributes to studies on gold-based catalysts with an irregular shape.
- Research Organization:
- Harvard Univ., Cambridge, MA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0012573
- OSTI ID:
- 1597444
- Alternate ID(s):
- OSTI ID: 1636030
- Journal Information:
- Surface Science, Vol. 679, Issue C; ISSN 0039-6028
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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