| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Nanomaterials | Monday Sessions |
| Session NM-MoE |
| Session: | Nanocatalysis |
| Presenter: | Monica McEntee, University of Virginia, USA |
| Authors: | M. McEntee, University of Virginia, USA J. Wang, Oak Ridge National Laboratory, USA W. Tang, University of Virginia, USA M. Neurock, University of Virginia, USA A.P. Baddorf, Oak Ridge National Laboratory, USA P. Maksymovych, Oak Ridge National Laboratory, USA J.T. Yates, Jr., University of Virginia, USA |
| Correspondent: | Click to Email |
Fabrication of highly active, stable and selective nanocatalysts requires an understanding of the mechanisms that control charge transfer and the activation of adsorbate interactions at specific surface sites. Here I report on the nature of low coordinated Au sites (likely to be on Au nanoparticles) by creating nano-pits on a Au (111) single crystal surface using scanning tunneling microscopy (STM). At room temperature, CO molecules adsorb on Au atoms and form Au-CO complexes, which allow for Au atom extraction from dislocation sites of the herringbone reconstruction. These complexes migrate and form Au clusters on elbows and edges of the Au surface. In conjunction with STM, transmission infrared (IR) spectroscopy and density functional theory (DFT) calculations were used to understand this new mechanistic motif. The mechanism for the Au atom extraction involves electron transfer from CO to Au forming positive charge on CO that creates stronger bonding with Au atoms of lower coordination number. Nanocatalysts involving Au nanoparticles with an abundance of low coordinated Au sites likely exhibit similar properties and these studies could foster future enhanced catalysts.